2024-03-29T01:20:02Zhttps://escholarship.org/oaioai:escholarship.org:ark:/13030/qt3s80t0pj2011-11-04T17:12:35Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3s80t0pjHicks, JohnauthorRamanathan, NithyaauthorFalaki, HosseinauthorLongstaff, BrentauthorParameswaran, KannanauthorRahimi, MohammadauthorKim, DonnieauthorSelsky, JoshuaauthorJenkins, JohnauthorEstrin, Dauthor2011-11-04Advances in technology and infrastructure have positioned mobile phones as a convenient platform for real-time assessment of an individuals health and behavior, while offering unprecedented accessibility and affordability to both the producers and the consumers of the data. In this paper we address several of the key challenges that arise in leveraging smartphones for health: designing the complex set of building blocks required for an end-to-end system, motivating participants to sustain engagement in long-lived data collection, and interpreting both the data and the quality of the data collected.We present AndWellness, a mobile to web platform that records, analyzes, and visualizes data from both prompted experience samples entered by the user, as well as continuous streams of data passively collected from sensors onboard the mobile device. In order to address the system design and participation motivation challenges, we have incorporated feedback from hundreds of behavioral and technology researchers, focus group participants, and end-users of the system in an iterative design process. AndWellness additionally includes rich system and user analytics to instrument the act of participation itself and ultimately to contextualize and better understand the factors affecting the quality of collected data over time. We evaluate the usability and feasibility of AndWellness using data from 3 studies with a variety of populations including young moms and recent breast cancer survivors. More than 85% of the diverse set of participants who responded to exit surveys claim they would use AndWellness for further personal behavior discovery.publicSystemsStatistics and Data PracticesUrban SensingOther Computer EngineeringDesignHuman FactorsExperimentationExperience SamplingWireless Health MonitoringAndWellness: An Open Mobile System for Activity and Experience Samplingarticlelocaloai:escholarship.org:ark:/13030/qt95t603tj2011-08-02T17:02:07Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/95t603tjAcker, AmeliaauthorLukac, MartinauthorEstrin, Deborahauthor2010-11-30Participatory Sensing is a process whereby individuals and communities use mobile phones and web services to observe, analyze, and present personal and environmental artifacts, events and experiences. In this technical report we describe a community data campaign that made use of smartphone based participatory sensing for environmental needs assessment. Community organizers defined the content of the participatory sensing campaign. 68 individuals participated over the course of 6 weeks, uploading over 450 mini-surveys, including over 700 images.publicUrban SensingCommunity-based ResearchCommunity EngagementOther Computer Sciencesparticipatory sensingcommunity-data campaignsparticipatory researchmobile data collectionParticipatory Sensing for Community Data Campaigns: A case studyarticlelocaloai:escholarship.org:ark:/13030/qt0nj8w1pm2011-07-08T17:29:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0nj8w1pmL. GirodauthorT. StathopoulosauthorN. RamanathanauthorM. LukacauthorA. ParkerauthorR. GuyauthorD. Estrinauthor2005-01-01EmStar is a software system for developing and deploying wireless sensor networks involving Linux-based platforms. As the wireless sensor network community has attempted to deploy more complex designs---large-scale, long-lived systems that need self-organization and adaptivity---a number of difficult software design issues have arisen. Advances in software design have not kept pace with the capabilities of hardware. This is because designing for an adaptive, efficient, and useful sensor network has turned out to be surprisingly complex and difficult. EmStar is a Linux-based software framework, whose goal is to dramatically reduce this complexity, enabling work to be shared and reused, and simplifying and speeding the design of new sensor network applications.publicEmStar Software Environmentarticlelocaloai:escholarship.org:ark:/13030/qt8867594b2011-07-03T21:12:23Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8867594bRundel, P WauthorGraham, Ericauthor2009-01-01Environmental sensor networks offer a powerful combination of distributed sensing capacity, real-time data visualization and analysis, and integration with adjacent networks and remote sensing data streams. These advances have become a reality as a combined result of the continuing miniaturization of electronics, the availability of large data storage and computational capacity, and the pervasive connectivity of the Internet. Environmental sensor networks have been established and large new networks are planned for monitoring multiple habitats at many different scales. Projects range in spatial scale from continental systems designed to measure global change and environmental stability to those involved with the monitoring of only a few meters of forest edge in fragmented landscapes. Temporal measurements have ranged from the evaluation of sunfleck dynamics at scales of seconds, to daily CO2 fluxes, to decadal shifts in temperatures. Above-ground sensor systems are partnered with subsurface soil measurement networks for physical and biological activity, together with aquatic and riparian sensor networks to measure groundwater fluxes and nutrient dynamics. More recently, complex sensors, such as networked digital cameras and microphones, as well as newly emerging sensors, are being integrated into sensor networks for hierarchical methods of sensing that promise a further understanding of our ecological systems by revealing previously unobservable phenomena.publicTerrestrialaquatic ecosystemsdata managementimagersmobile sensorssensor networkssoil ecosystemswireless sensorsTansley Review: Environmental sensor networks in ecological researcharticlelocaloai:escholarship.org:ark:/13030/qt8pq5g7rm2011-07-03T21:12:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8pq5g7rmGraham, Ericauthor2008-01-01Plant phenology relates strongly to primary productivity and the energy that enters into ecological food webs, and thus is vital in understanding ecosystem function and the effects of climate and climate change. The manual collection of phenological data is labor-intensive and not easily scalable, thus the ability to quantify leaf flush and other parameters at many locations requires innovative new methodologies such as the use of visible light digital cameras. Improved imaging performancewas obtained by using a cabled, mobile camera system that allowed a repeated image census of branches of Rhododendron occidentale in the understory along a 30m transect during leaf flush. Automatic division of acquired images into areas of interest (leaves) and background for calculating leaf area was accomplished by thresholding images in different color spaces. Transformation of the color space into the hue, saturation, and luminance (HSL) color space before thresholding resulted in a mean RMS error of 21.2 cm2 compared to hand-counts of leaf area. Thresholding in the native red, green, and blue (RGB) color space to isolate leaves resulted in a larger error, as did using algebraic combinations of the color components or color ratios. Relating physiological function to images, as for sap flow for branches of R. occidentale, indicates that the greening and calculated leaf area of a species as detected by imagers requires additional meteorological sensor data for interpretation.publicTerrestrialOther Plant SciencesDigital cameraGreen-upRoboticHSL color spaceBudburst and leaf area expansion measured with a ground-based, mobile camera system and simple color thresholdingarticlelocaloai:escholarship.org:ark:/13030/qt3z79z6h62011-07-03T18:40:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3z79z6h6Pavlin RadoslavovauthorChristos PapadopoulosauthorRamesh GovindanauthorDeborah Estrinauthor2004-01-01publicA Comparison of Application-Level and Router-Assisted Hierarchical Schemes for Reliable Multicastarticlelocaloai:escholarship.org:ark:/13030/qt8db3f7mr2011-07-03T18:39:56Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8db3f7mrXi WangauthorFabio SilvaauthorJohn Heidemannauthor2003-01-01Directed diffusion is a data-centric communication mechanism for sensor networks. It is supported by a flexible diffusion filter framework. GPSR (greedy perimeter stateless routing) is a routing mechanism commonly used in sensor networks. This project is an effort to connect GPSR with directed diffusion. Compared with existing routing mechanisms in the diffusion platform, including push, pull and gear, GPSR has quite different qualities in performance. It is an importation addition to the diffusion platform. As a widely known protocol, GPSR is also a good benchmark for ongoing and future research works. In this project, GPSR is implemented as a filter in the diffusion platform, and we performed simulations to compare the performance of different routing mechanisms. There are two findings from simulations results: a) overall GPSR is a rather efficient routing protocol. B) the behavior of GPSR is quite sensitive to node density. The performance will degrade significantly for sparse (barely connected) wireless networks. The poster will show simulation results with analysis. It will also show the internal structure and interfaces of the GPSR filter, as the implementation of the GPSR filter is good example of integrating new routing filters to the diffusion platform.publicEvaluation of GPSR in the Diffusion Filter Frameworkarticlelocaloai:escholarship.org:ark:/13030/qt6wv369j62011-07-03T18:35:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6wv369j6Monica KohlerauthorIgor StubailoauthorPaul DavisauthorDeborah EstrinauthorRichard GuyauthorRamesh GovindanauthorRobert NigborauthorMark HansenauthorAndrew BaekauthorTom HeatonauthorCase BradfordauthorJohn WallaceauthorDerek Skolnikauthor2006-01-01A main thrust of the seismic application is the development of algorithms for performing high spatial resolution measurements and modeling of structures using wired and wireless arrays. The UCLA Factor building is a testbed for predictive numerical modeling, wireless network, and smart event-detection developments related to structural health monitoring. Waveform data from the 72-node array in the 17-story moment-resisting steel frame Factor building are used in comparison with finite element calculations for predictive behavior.publicSEI 2: Embedded Wired and Wireless Seismic Networks for Structural Health Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt8kt128f62011-07-03T18:33:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8kt128f6Nithya RamanathanauthorLaura BalazanoauthorSaurabh GaneriwalauthorRam KumarauthorShane MarkstrumauthorRoy SheaauthorDeborah EstrinauthorEddie KohlerauthorRupak MajumdarauthorTodd MillsteinauthorMani Srivastavaauthor2006-01-01As wireless sensors networks become a critical part of applications with significant scientific, economic, and safety impact, issues of system and data integrity have gained importance. Careful design and calibration prior to deployment are insufficient to ensure integrity in the presence of environmental uncertainties, hardware and software faults, changes in hardware characteristics, and malicious manipulation of system behavior. The fragile nature of current systems is a bottleneck in scaling the embedded sensing technology. This poster describes CENS research in three different aspects of the integrity problem: sensor data integrity, software faults, and security attacks.publicSYS 4: Designing High Integrity Embedded Networked Sensing Systemsarticlelocaloai:escholarship.org:ark:/13030/qt71j5p7cq2011-07-03T18:33:12Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/71j5p7cqMohammand RahimiauthorShaun AhmadianauthorShyamal ChandraauthorHyungjin KimauthorRam KumarauthorRafael LauferauthorDong-U LeeauthorKevin LeeauthorJeff MasciaauthorSameera PoduriauthorDavid ZatsauthorDeborah EstrinauthorMani SrivastavaauthorJohn Villasenorauthor2006-01-01Sensor network research faces challenges in exploiting vision, the most powerful of human senses. In our earlier research we presented Cyclops, a new CMOS based low power and low complexity imaging sensor with on-board computation. In this poster, we present recent advances in exploiting Cyclops in a vision network. This includes our approach to building reconfigurable and customized computations. We illustrate our systems ability to be incrementally updated after deployment, including the addition and removal of image processing libraries. This enables flexible and dynamic image processing based on the variation in requirements of the applications or in response to the environmental variations. In addition, we illustrate our progress in exploiting Cyclops in application domains. We present a tiered system which uses a stereo pair of Cyclops to locate objects in three dimensional spaces for further investigation by an actuated vision node. Finally, we demonstrate our recent deployment of a network of Cyclops for monitoring wildlife and habitat at James San Jacinto Mountains Reserve.publicSYS 3: Cyclops A Reconfigurable Low-power Platform for Distributed Image Sensingarticlelocaloai:escholarship.org:ark:/13030/qt38m7c4g82011-07-03T18:32:56Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/38m7c4g8Lewis GirodauthorMartin LukacauthorVlad TrifaauthorDeborah Estrinauthor2006-01-01The Acoustic Embedded Networked Sensing Box, is a platform for prototyping rapid-deployable distributed acoustic sensing systems, particularly distributed source localization. Each ENSBox integrates an ARM processor running Linux and supports key facilities required for source localization: a sensor array, wireless network services, time synchronization, and precise self-calibration of array position and orientation. The ENSBoxs integrated high precision self-calibration facility sets it apart from other platforms, in that its results in complex, realistic environments are precise enough to support acoustic source localization applications.publicSYS 2: Acoustic ENSBox A System of Self Calibrating Distributed Acoustic Arraysarticlelocaloai:escholarship.org:ark:/13030/qt95h363qs2011-07-03T18:32:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/95h363qsOm GnawaliauthorBen GreensteinauthorRamakrishna GummadiauthorKi-Young JangauthorAugust JokiauthorNupur KothariauthorPaek, JeongyeupauthorMarcos VieiraauthorDeborah EstrinauthorRamesh GovindanauthorEddie KohlerauthorTodd Millsteinauthor2006-01-01Existing programming systems and tools for observing systems are primitive and do not promote much code reuse. There is a pressing need for revisiting sensor network architecture to increase reusability and manageability, as well as higher-level programming abstractions that can help reduce the development cycle. This poster illustrates three on-going efforts that address these challenges. The Tenet project proposes a novel architecture for sensor networks that simplifies application development and improves system manageability and robustness, while the Vango and Kairos projects significantly raise the level of abstraction to the point where programmers need not concern themselves with communication and resource management issues.publicSYS 1: Programming and Architecting Embedded Networked Systemsarticlelocaloai:escholarship.org:ark:/13030/qt9951c5sx2011-07-03T18:29:27Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9951c5sxCathy KongauthorWilliam KaiserauthorGreg Pottieauthor2006-01-01Environment reconstruction through sampling is a difficult task and usually requires a large amount of resources. In some applications such as the sun light field reconstruction, the sensors are very expensive. Hence, reducing the number of samples while meeting the distortion requirement becomes very important in such applications. Many phenomena can be measured by different types of sensors, which provide information at different scales and accuracy. Prior knowledge and external information may serve to provide the global information. By exploiting the underlying models of the phenomenon, we efficiently deploy the sensors and combine the information from different levels. In this way, we can approach the reconstruction accuracy reached by exhaustive sensing in one level with much less number of sensors.publicModel Based Multiscale Sensing (MAS 5)articlelocaloai:escholarship.org:ark:/13030/qt9q81q2zj2011-07-03T18:28:39Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9q81q2zjDohyun KimauthorJack W. JudyauthorIra B. Goldbergauthor2003-01-01We have conducted feasibility studies based on chronocoulometry of nitrate for the purpose of fabricating a miniaturized sensor. Detection and monitoring of nitrate ion in surface water are important because of environmental and ecological influence of nitrate. For this application, sensors should be small, stand-alone, and have a low detection limit. Conventional nitrate sensing methods (spectroscopy, chromatography, electrophoresis, etc.) Do not meet aforementioned requirements because of the cumbersome sample preparation and complex implementation. Electrochemical detection is simple and a sensor can be easily miniaturized when using this method. The proposed electrochemical cell (silver working electrode, platinum counter electrode, ag/agcl reference electrode, and sodium hydroxide supporting electrolyte) shows high sensitivity for the nitrate ion detection. Oxygen dissolved in aqueous electrolyte interferes with the nitrate detection, but was successfully removed by a simple differential approach.publicMicromachined Amperometric Nitrate Sensorarticlelocaloai:escholarship.org:ark:/13030/qt6n4945xt2011-07-03T18:27:53Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6n4945xtOnur SertauthorMarcos VieiraauthorGaurav S. SukhatmeauthorRamesh Govindanauthor2006-01-01We investigate the differential pursuit-evasion games between multiple pursuers and multiple evaders. Pursuers make use of a hierarchical sensor network embedded in the environment in order to perceive the evader locations. Evaders are localized to some topological nodes using "Received Signal Strength Indication" (RSSI), which results in a coarse estimate of the evader locations. Based on this information and particle filter based self-localization of the pursuers, we use optimal and sub-optimal pursuit-policies and some task allocation schemes so that the pursuers capture the evaders in a time optimal manner. The effect of sensing errors and other network related errors due to communication delay and packet loss on the pursuit-evasion games are also investigated.publicPursuit-Evasion Games Using Sensor Networks (MAS 11)articlelocaloai:escholarship.org:ark:/13030/qt4b54228v2011-07-03T18:27:11Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4b54228vSrikanth SaripalliauthorJonathan KellyauthorGaurav S. Sukhatmeauthor2006-01-01We present a method for highly accurate surveying using an autonomous helicopter equipped with a downward looking camera. Given a location that needs to be mapped the helicopter creates accurate aerial maps by combining visual data with inertial and GPS data. We present initial results that show maps of Lake Fulmor using the helicopter. These maps were created manually but they demonstrate the method used.publicRobotic Helicopter Surveying (MAS 13)articlelocaloai:escholarship.org:ark:/13030/qt6k64v5hk2011-07-03T18:26:28Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6k64v5hkLewis GirodauthorMartin LukacauthorAndreas MantikauthorVlad TrifaauthorTravis CollierauthorDeborah Estrinauthor2006-01-01The deployment of autonomous recoding devices has enabled behavioral biologists, conservation biologists, and ecologists to address a host of scientific questions including problems which were impractical or impossible without such devices. By adding the ability to spatially locate the source of vocalizations, a host of new possibilities have been opened. We have developed self-localizing field-deployable acoustic sensors that can coordinate to detect, record, localize, and enhance animal calls and bird songs. Ongoing improvements focus on making the system more robust and easy to use, as well as improving detection and localization algorithms using a paradigm which includes inter-node collaboration.publicSelf-Calibrating Distributed Acoustic Sensor Array: Localization of Bio-acoustic Sources (SYS 3)articlelocaloai:escholarship.org:ark:/13030/qt2kf8m3712011-07-03T18:25:25Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2kf8m371Vinayak NaikauthorLewis GirodauthorMartin LukacauthorNithya RamanathanauthorBenjamin GreensteinauthorEddie KohlerauthorDeborah Estrinauthor2006-01-01EmStar served its primary purpose, based on the past 5 years, we have found that we also need a system that can take care of previously unhandled issues, viz. memory access errors resulting in a runtime crash, lack of portability across platforms other than Linux, and manageability issues during deployment due to multiple processes. These issues have led us to redesign EmStar to better serve the wide-range of needs of programming development environment of the 32-bit class of embedded devices in wireless sensor networks. This second version of EmStar, hence forth called as or EmStar-2, has automatic garbage collection for better runtime memory management, portability across platforms other than Linux, runtime exception handling to reduce crashesing, and single process with single thread of control for better manageability during deployments, etc. In addition, EmStar-2 will still be able to seamlessly integrate with the existing EmStar toolsets, there by reaping the benefits of the rich library provided by code-base existing that exists in EmStar.publicEmStar-2: The Next Generation Programming Development Environment for 32-bit Class of Embedded Devices (SYS 9)articlelocaloai:escholarship.org:ark:/13030/qt6434t2m82011-07-03T18:24:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6434t2m8Martin LukacauthorLewis GirodauthorDeborah Estrinauthor2006-01-01publicDisruption Tolerant Shell (SYS 13)articlelocaloai:escholarship.org:ark:/13030/qt7wq6q87h2011-07-03T18:24:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7wq6q87hTad DreierauthorSadaf ZahediauthorThomas SchmidauthorMani Srivastavaauthor2006-01-01Software defined radio provides unique benefits as well as challenges. Our work in advanced channel access schemes and base stations for sensor networks exploit the flexibility of SDR, while our unified design enviornment addresses t he challenges that come with the multidisciplinary nature of SDR.publicSDRCADE: Software Defined Radio for Efficient Channel Access, Flexible Sensor Network Gateways, and a Rapid Develeopment Enviornment (SYS 16)articlelocaloai:escholarship.org:ark:/13030/qt5251z9bp2011-07-03T18:21:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5251z9bpMelissa CookauthorDeborah FieldsauthorWilliam A. Sandovalauthor2006-01-01publicYou guys are going to pretend to be a scientist: Positioning talk in science inquiry classrooms (EDU 2)articlelocaloai:escholarship.org:ark:/13030/qt6n71w2gg2011-07-03T18:20:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6n71w2ggAmit DhariwalauthorGaurav S. SukhatmeauthorAristides A.G. RequichaauthorDavid CaronauthorCarl ObergauthorBeth StaufferauthorEric Shiehauthor2005-01-01publicSensor-Actuated Roboduck Network for Marine Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt1134z2042011-07-03T18:19:45Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1134z204Beth StaufferauthorDavid CaronauthorMrinal MahapatroauthorAri Requichaauthor2005-01-01publicDetection and Identification of Marine Microorganismsarticlelocaloai:escholarship.org:ark:/13030/qt4v52f4q62011-07-03T18:18:58Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4v52f4q6Carl ChinauthorYu Qing HeauthorCarl ChinauthorYu-Chong Tai Chong Taiauthor2005-01-01publicIon Liquid Chromatography On Ion Liquid Chromatography On-a-Chip Chiparticlelocaloai:escholarship.org:ark:/13030/qt7gk0d9rh2011-07-03T18:17:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7gk0d9rhKaren KimauthorWesley UeharaauthorDeborah EstrinauthorWilliam KaiserauthorGregory PottieauthorRichard Guyauthor2005-01-01CENS undergraduate and graduate programs are designed to provide an educational pipeline to graduate school and increase the diversity of CENS and those pursuing education and careers in science and engineering.publicEDU1: CENS Graduate and Undergraduate Student Programsarticlelocaloai:escholarship.org:ark:/13030/qt43w910tr2011-07-03T18:16:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/43w910trPaul DavisauthorAllen HuskerauthorIgor StubailoauthorRichard GuyauthorSam IrvineauthorJohn Propstauthor2005-01-01The first long term scientific deployment of the portable broadband seismic array is a part of MASE (Middle America Subduction Experiment) in collaboration with California Institute of Technology and Universidad Nacional Autnoma de Mexico (UNAM). We are mapping the subducted slab beneath Mexico and examining slow earthquakes which have been observed at this subduction zone, volcanic earthquakes and the propagation of seismic waves in Mexico City which was devastated in the 1985 Michoacan earthquake. We will compare our 50 instrument wireless array with the 50 instruments of a stand-alone array that has been installed by Caltech. The transect covered by all stations is 500 km long between Acapulco-Mexico City-Tampico.publicSEI2: Wide Area Wireless Networks for Geophysicsarticlelocaloai:escholarship.org:ark:/13030/qt0dx3t8pb2011-07-03T18:15:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0dx3t8pbMonica KohlerauthorPaul DavisauthorIgor StubailoauthorJohn Wallaceauthor2005-01-01A testbed for structural health monitoring uses the embedded 72-sensor seismic network in the UCLA Factor building which records continuous data at 500 Hz. In addition, a 15-station prototype wireless seismic monitoring array has been developed and tested. It is based on the Crossbow mote technology and will be run side by side with digitzers in Factor for comparison.The Mica-2 mote network is controlled by Wisden software and is designed to monitor local areas such as buildings. Data from the wired building array have been used to compute time-varying displacements in 3D, to compute the finite impulse response of the building during the 9/28/04 Parkfield and 12/16/04 Santa Monica Bay earthquakes, and to apply time series analysis techniques to long time series and stacked spectra to identify the higher modes of vibration. Modes of building vibration are found to decrease in frequency at the times of large amplitude shaking by earthquakes or wind.publicSEI1: Sensor Networks for Real Time Monitoring State of Health of Buildingsarticlelocaloai:escholarship.org:ark:/13030/qt28p3k1rj2011-07-03T18:15:42Z am 3u Center for Embedded Network SensingVol. 24, no. 4 (Nov. 2008) 969-995eScholarship, University of Californiahttps://escholarship.org/uc/item/28p3k1rjYu, EunjongauthorSkolnik, DerekauthorWhang, Daniel H.authorWallace, John W.author2008-11-01The nees@UCLA mobile field laboratory was utilized to collect forced and ambient vibration data from a four-story reinforced concrete (RC) building damaged in the 1994 Northridge earthquake. Both low amplitude broadband and moderate amplitude harmonic excitation were applied using a linear shaker and two eccentric mass shakers, respectively. Floor accelerations, interstory displacements, and column and slab curvature distributions were monitored during the tests using accelerometers, linear variable differential transformers (LVDTs) and concrete strain gauges. The use of dense instrumentation enabled verification of common modeling assumptions related to rigid diaphragms and soil-structure-interaction. The first six or seven natural frequencies, mode shapes, and damping ratios were identified. Significant decreases in frequency cor responded to increases in shaking amplitude, most notably in the N-S direction of the building, most likely due to preexisting diagonal joint cracks that formed during the Northridge earthquake. DOI: 10.1193/1.2991300publicSeismicForced Vibration Testing of a Four-Story Reinforced Concrete Building Utilizing the nees@UCLA Mobile Field Laboratoryarticlelocaloai:escholarship.org:ark:/13030/qt2m71r5n02011-07-03T18:15:33Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2m71r5n0Paul DavisauthorAllen HuskerauthorMonica KohlerauthorIgor StubailoauthorRichard GuyauthorSam IrvineauthorJohn PropstauthorJohn Wallaceauthor2005-01-01publicSEI0: CENS Seismic Research: Overviewarticlelocaloai:escholarship.org:ark:/13030/qt12v1d7w32011-07-03T18:15:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/12v1d7w3Bin ZhangauthorGaurav S. Sukhatmeauthor2008-01-01publicAquaticAdaptive Sampling With Multiple Mobile Robotsarticlelocaloai:escholarship.org:ark:/13030/qt7nt8d1172011-07-03T18:15:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7nt8d117Stealey M.authorSingh A.authorBatalin M.authorJordan B.authorKaiser W.author2008-01-01publicMultiscaled Actuated SensingNIMSAQ: A novel system for autonomous sensing of aquatic environmentsarticlelocaloai:escholarship.org:ark:/13030/qt4cx5t82z2011-07-03T18:14:48Z am 3u Center for Embedded Network SensingVol. 2, no. 3 (Jan. 2008) 195-201eScholarship, University of Californiahttps://escholarship.org/uc/item/4cx5t82zRodriguez, Marko AauthorPepe, Albertoauthor2008-01-01This article presents a study that compares detected structural communities in a coauthorship network to the socioacademic characteristics of the scholars that compose the network. The coauthorship network was created from the bibliographic record of an overt interdisciplinary research group focused on sensor networks and wireless communication. The popular leading eigenvector community detection algorithm was employed to assign a structural community to each scholar in the network. Socioacademic characteristics were gathered from the scholars and include such information as their academic department, academic affiliation, country of origin, and academic position. A Pearson's \$\chi^2\$ test, with a simulated Monte Carlo, revealed that structural communities best represent groupings of individuals working in the same academic department and at the same institution. A generalization of this result indicates that, contrary to the common conception of a multi-institutional interdisciplinary research group, collaboration is primarily driven by scholar expertise and physical proximity.publicStatistics and Data PracticesOn the relationship between the structural and socioacademic communities of an interdisciplinary coauthorship networkarticlelocaloai:escholarship.org:ark:/13030/qt8wr1w9hh2011-07-03T18:10:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8wr1w9hhA. AliauthorS. AsgariauthorC.E. ChenauthorB.W. ChengauthorR.E. HudsonauthorF. LorenzelliauthorE. TacinrogluauthorL. VandenbergheauthorK. Yaoauthor2005-01-01In many sensor network applications, the localization of an emitting acoustic source as well as those of sensor nodes is of importance. In this poster, we first tackle the localization of the acoustic source by utilizing the Approximate-Maximum-Likelihood (AML) methodology. By using the virtual array method, the AML estimated direction-of-arrival (DOA) can be used to localize the source under controlled reverberant scenarios. For localization of an impulsive source, whitening of the observed data before the AML operation has been shown to be an effective operation. For wireless sensor node localization, we assume the locations of the anchor nodes are known. Range information among neighborhood sensor nodes as well as from sensor nodes to neighborhood anchor nodes are also available. By using the distributed Gauss-Newton estimation approach, a sequential algorithm and a parallel algorithm are shown to be efficient in determining the locations of the sensor nodes.publicSIP1: Acoustic Source and Wireless Sensor Node Localizationsarticlelocaloai:escholarship.org:ark:/13030/qt4kk1p8g02011-07-03T18:10:35Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4kk1p8g0G. Pottie (co-PI)authorM. PotkonjakauthorS. SoattoauthorM. SrivastavaauthorK. Yao (co-PI)author2005-01-01publicSIP0: CENS Sensor Information Processing Research Overviewarticlelocaloai:escholarship.org:ark:/13030/qt4q0921wh2011-07-03T18:05:38Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4q0921whDeborah EstrinauthorMiodrag PotonjakauthorDaniela RusauthorGaurav Sukhatmeauthor2005-01-01No abstractpublicNeTS-NOSS: Mobility NOSS: Mobility-assisted Network assisted Networkarticlelocaloai:escholarship.org:ark:/13030/qt5ft2s3052011-07-03T18:05:14Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5ft2s305Dustin McIntireauthorKei HoauthorBernie YipauthorAmarjeet SinghauthorWinston WuauthorWilliam J. Kaiserauthor2005-01-01A broad range of embedded networked sensor (ENS) systems for critical environmental monitoring applications now require complex, high peak power dissipation sensor devices as well as on-demand high performance computing and high bandwidth communication. Embedded computing demands for these new platforms include support for computationally intensive image and signal processing as well as optimization and statistical computing. To meet these new requirements while maintaining critical support for low energy operation, a new multiprocessor node hardware and software architecture,publicThe Low Power Energy Aware Processing (LEAP) Embedded Networked Sensor Systemarticlelocaloai:escholarship.org:ark:/13030/qt4g43c9qv2011-07-03T16:35:03Z am 3u Center for Embedded Network SensingVol. 87, no. 52 (Jan. 2006)eScholarship, University of Californiahttps://escholarship.org/uc/item/4g43c9qvRamanathan, NithyaauthorRothenberg, SarahauthorEstrin, DauthorHarmon, T CauthorHarvey, CharlesauthorJay, J AauthorKohler, Eddieauthor2006-01-01The presence of arsenic in the groundwater has led to the largest environmental poisoning in history; tens of millions of people in the Ganges Delta continue to drink groundwater that is dangerously contaminated with arsenic. A current working hypothesis is that arsenic is mobilized in the near surface environment where sediments are weathered by seasonal changes in the redox state that drive a cycle of pyrite oxidation and iron oxide reduction. In order to test the supporting hypothesis that subsurface geochemical changes may be induced by agricultural activity, we deployed 42 wirelessly networked ion-selective electrodes, including calcium, ammonium, nitrate, ORP, chloride, carbonate, and pH in a rice paddy in the Munshiganj district of Bangladesh in January of 2006. Each sensor was connected to an MDA300 sensor board and Mica2 wireless transceiver and computational device. Over a period of 11 days, we observed clear diel, and diurnal trends in 4 of the electrodes (calcium, ammonium, chloride and carbonate). The trends may be due to hydrological changes, or geochemical changes induced either by photosynthesis in the overlying water (which then infiltrated to the depth of the sensors) or in the root zone of rice plants. While the spatiotemporally dense measurements from wireless sensor networks enable scientists to ask new questions and elucidate complex relationships in heterogeneous physical environments such as soil, there are many practical issues to address in order to collect data usable for scientific purposes. For example, in response to a stream of faults in one of our sensor network deployments, we designed Sympathy to enable users to find and fix problems impacting the quantity of data collected in the field. Sympathy detects packet loss experienced at the base station and systematically assigns blame to faulty components in the network for remediation, replacing the prior policy of ad-hoc node rebooting and battery replacements. Sympathy has been deployed in many habitat monitoring sensor networks. While using Sympathy at our Bangladesh field site we received 80% of the sensor data expected at the base station, upon returning, post-deployment analysis revealed that 42% of these sensor data were potentially faulty. Due to the remote location of the deployment, we were unable to go back and validate the questionable segments of the data set, forcing us to discard potentially interesting information. In addition to being undesirable, this response is often avoidable as well. Even simple actions such as checking sensor connections and quickly validating sensors in the field could have increased our confidence in the quality of the data, minimizing doubts that data observations were simply caused by badly behaving hardware. To improve data quality, we have designed a system called Confidence, which continuously monitors data collected at a base-station to identify faulty data and notify the user in the field of actions they can take to validate the data or remediate the sensor fault. Augmenting a sensor network deployment with Confidence and Sympathy enables users in the identification and remediation of faults impacting the quality and quantity of data respectively.publicContaminant TransportInvestigation of Hydrologic and Biogeochemical Controls on Arsenic Mobilization Using Distributed Sensing at a Field Site in Munshiganj, Bangladesharticlelocaloai:escholarship.org:ark:/13030/qt69s787762011-07-03T16:27:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/69s78776Gummadi, RamakrishnaauthorKothari, NupurauthorMillstein, ToddauthorGovindan, Rameshauthor2007-03-12Wireless sensor networks consist of a system of distributed sensors embedded in the physical world, and promise to allow observation of previously unobservable phenomena. Since they are exposed to unpredictable environments, sensor-network applications must handle a wide variety of faults: software errors, node and link failures, and network partitions. The code to manually detect and recover from faults crosscuts the entire application, is tedious to implement correctly and efficiently, and is fragile in the face of program modifications. We investigate language support for modularly managing faults. Our insight is that such support can be naturally provided as an extension to existing “macroprogramming” systems for sensor networks. In such a system, a programmer describes a sensor network application as a centralized program; a compiler then produces equivalent node-level programs. We describe a simple checkpoint API for macroprograms, which can be automatically implemented in a distributed fashion across the network. We also describe declarative annotations that allow programmers to specify checkpointing strategies at a higher level of abstraction. We have implemented our approach in the Kairos macroprogramming system. Experiments show it to improve application availability by an order of magnitude and incur low messaging overhead.publicSystemsWSNMacroprogrammingNode-level programmingDeclarative Failure RecoveryCheckpointingDeclarative Failure Recovery for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt6p95c0fh2011-07-03T16:27:23Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6p95c0fhD. GanesanauthorB. GreensteinauthorD. PerelyubskiyauthorD. EstrinauthorJ. Heidemannauthor2003-01-01Wireless sensor networks enable dense sensing of the environment, offering unprecedented opportunities for observing the physical world. Centralized data collection and analysis adversely impact sensor node lifetime. Previous sensor network research has, therefore, focused on in network aggregation and query processing, but has done so for applications where the features of interest are known a priori. When features are not known a priori, as is the case with many scientific applications in dense sensor arrays, efficient support for multi-resolution storage and iterative, drill-down queries is essential. Our system demonstrates the use of in-network wavelet-based summarization and progressive aging of summaries in support of longterm querying in storage and communication-constrained networks. We evaluate the performance of our linux implementation and show that it achieves: (a) low communication overhead for multi-resolution summarization, (b) highly efficient drill-down search over such summaries, and (c) efficient use of network storage capacity through load-balancing and progressive aging of summaries.publicAn evaluation of multi-resolution search and storage in resource-constrained sensor networksarticlelocaloai:escholarship.org:ark:/13030/qt9261v4zx2011-07-03T16:27:03Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9261v4zxArnaud BenahmedauthorNikolaus RechnerauthorChih Ming Hoauthor2005-01-01Surface Plasmons (SP) are electromagnetic waves that propagate on the interface between a metal, such as gold, and a dielectric. Because they are waves concentrated around the interface, they are very sensitive to minute changes of dielectric constant on the interface. Monitoring surface plasmon propagation can therefore be used to measure the binding of molecules on top of a metallic surface, a technique called Surface Plasmon Resonance (SPR) detection. This technique is however too fragile and bulky to be incorporated in a network of embedded sensors. By using the properties of the propagation of SP in periodic media, we are exploring a new paradigm for surface plasmon sensing that will enable sensors that are much more robust and reliable. Because these sensors can be adapted to the specific detection of most molecules, we believe that they will become ultimately a powerful solution for embedded biological sensing.publicUsing Surface Plasmon Band Gap for robust, on-field, biological and chemical detectionarticlelocaloai:escholarship.org:ark:/13030/qt8wb4118r2011-07-03T16:26:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8wb4118rKaren KimauthorChristine BorgmanauthorJune ChangauthorMelissa CookauthorAmy FannauthorDeborah FieldsauthorKathy GriffisauthorRichard Guy Aletha HarvenauthorKelli MillwoodauthorWilliam SandovalauthorLinda SaxauthorVandana ThadaniauthorWesley UeharaauthorJillian WallisauthorJoe WiseauthorDeborah EstrinauthorMichael AllenauthorDave CaronauthorPaul DavisauthorEric GrahamauthorRamesh GovindanauthorMichael HamiltonauthorMark HansonauthorTom HarmonauthorJohn HeidemannauthorJenny JayauthorWilliam KaiserauthorJens PalsbergauthorGreg PottieauthorMohammad RahimiauthorPhil RundelauthorMani SrivastavaauthorGaurav SukhatmeauthorYu-Chong Tauthor2006-01-01publicEDU 0: Education Overviewarticlelocaloai:escholarship.org:ark:/13030/qt3kv078m42011-07-03T16:26:20Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3kv078m4Deborah EstrinauthorChristine BorgmanauthorLinda SaxauthorJune ChangauthorAmy FannauthorKaren KimauthorWes Ueharaauthor2006-01-01At CENS, our diversity initiatives continue to gain momentum. We have developed several programs designed to increase the number of diverse students pursuing advanced degrees in CENS related fields, particularly women, underrepresented minorities, and US citizens. To that end, we have developed a number of key projects to help establish a pipeline to graduate school and CENS research. Our Women@CENS program is designed to promote gender equity by focusing on our summer internship program and research promising practices of undergraduate research programs nationally. We have also established collaboration with other STCs, partnering institutions and local colleges and organizations that focus on serving underrepresented students. These programs are designed not only to help us provide services and opportunities that support gender equity and underrepresented minorities but also to identify promising diversity practices that can be broadly shared.publicEDU 2: Diversity at CENSarticlelocaloai:escholarship.org:ark:/13030/qt9xm259522011-07-03T16:26:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9xm25952Paul DavisauthorMonica KohlerauthorDeborah EstrinauthorRichard GuyauthorRamesh GovindanauthorIgor StubailoauthorAllen HuskerauthorMartin LukacauthorSam Irvineauthor2006-01-01publicSEI 0: Embedded Network Approaches to Multiscale Seismic Networks Overviewarticlelocaloai:escholarship.org:ark:/13030/qt8xh7q6w32011-07-03T16:26:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8xh7q6w3Aman KansalauthorWilliam J. KaiserauthorGregory J. PottieauthorMani B. SrivastavaauthorGaurav Sukhatmeauthor2006-01-01The resolution at which a sensor network observes the environment is a crucial parameter of performance since it governs the range of applications that are feasible using that network. A higher resolution, in most situations, enables more applications and improves the reliability of existing ones. For science applications for instance, a higher resolution may yield newer insights into the phenomenon than available from lower resolution data. In this poster we discuss a system architecture that uses controlled motion to provide virtual high-resolution in a network of cameras. Several orders of magnitude advantage in resolution is achieved. We discuss several system design choices in the context of our prototype camera network implementation that realizes the proposed architecture. Real world data is collected using our prototype system and used for the evaluation of our proposed methods.publicMAS 3: Coordinated Actuation for Environment Observationarticlelocaloai:escholarship.org:ark:/13030/qt17q969sm2011-07-03T16:26:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/17q969smSameer PoduriauthorVinay MallekalauthorAjay DeshpandeauthorGaurav SukhatmeauthorDaniela Rusauthor2006-01-01The performance of camera sensors placed in harsh outdoor environments varies drastically because of factors such as lighting conditions, background contrast, luminance, etc. which are very hard to model. We present a data-driven approach to minimize the number of cameras while ensuring complete sensing coverage. A network of Cyclops cameras were deployed in the UCLA botanical gardens to detect moving people, Based on the data, we estimated detection ranges at a large number of points and found optimal camera locations.publicCoverage Optimization with a location dependent Sensing Quality (MAS 7)articlelocaloai:escholarship.org:ark:/13030/qt4c09r01d2011-07-03T16:26:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4c09r01dKannika SikangwanauthorMiodrag Potkonjakauthor2006-01-01We address one of the canonical problems in sensor networks - integrity of collected datapublicOptimal and Heuristic Techniques for Fault Detection (MAS 8)articlelocaloai:escholarship.org:ark:/13030/qt5mz9f1d82011-07-03T16:25:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5mz9f1d8Xiangming KongauthorWilliam KaiserauthorGreg Pottieauthor2006-01-01In many environment sensing applications, we can observe the field by multiple types of sensors in multiple levels. We propose that we can achieve the accuracy of exhaustive sensing at one level by sparse sensing at multiple levels. Our previous results proved that we do achieve the same reconstruction accuracy as exhaustive sensing with reduced number of sensors. But by fusing measurement from different sensors directly in our previous approach, the improvement is limited. In our current work, we established field models to incorporate more information. The distribution models help assign uncertainty to the measurements. By applying correlation models in reconstruction process, we can probe the structure in the data and further improve reconstruction accuracy.publicMAS 2: Multiscale Actuated Sensing Theoryarticlelocaloai:escholarship.org:ark:/13030/qt5jj5q1hj2011-07-03T16:25:45Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5jj5q1hjSatish VedantamauthorUrbashi MitraauthorAshutosh Sabharwalauthor2006-01-01A joint sensing/communication problem is considered for sensor networks. Herein, the channel(s) between a source and destination are the parameters to be sensed and communicated over the network. Lower bounds on the end-to-end distortion are developed for a multihop, linear network. Inter-node communication is assumed to be done via an amplify-and-forward approach and the results are compared to those previously presented for an encode-and-forward approach. It is shown that amplify-and-forward has the potential to significantly outperform encode-and-forward. Furthermore, with respect to an asymptotic measure which evaluates the rate of decay of the mean-squared error with respect to the SNR, amplify-and-forward can achieve the maximal possible decay rate.publicMultihop Sensing and Communication Networks (SEN 5)articlelocaloai:escholarship.org:ark:/13030/qt4312j4732011-07-03T16:25:39Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4312j473Rodrigo VargasauthorAlisha GlassauthorMike TaggartauthorKuni KitajimaauthorMichael HamiltonauthorMichael Allenauthor2006-01-01The prototype of the automated minirhizotron (AMR) has demonstrated better image quality than conventional manual minirhizotrons. The AMR is capable to record images at user-defined intervals that will be able to capture short-term ecological changes. We have compiled an image database with >60,000 images from manual minirhizotrons at the James Reserve, CA since June 2005. Images were analyzed manually and we used the MARK capture-recapture program to calculate the root survival rate. Preliminarily results suggest that new-born roots have a shorter lifespan than old ones (9 days vs. 24 days). Additionally to the root image analysis we have data from our soil sensor array or soil temperature moisture and soil CO2. We measured CO2 concentration at three soil depths to calculate soil respiration based on CO2 gradients and diffusivity. Data collected from these sensors have increased the understanding of spatio-temporal variation in soil respiration and its relation with root dynamics. To identify the fungal biota participating in soil biogeochemical processes we isolated fungal hyphae from soil.publicLinking minirhizotron images to soil physical properties and microbial diversity (TER 2)articlelocaloai:escholarship.org:ark:/13030/qt7hz560ds2011-07-03T16:25:35Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7hz560dsBrian FulkersonauthorStefano SoattoauthorMike AllenauthorMike TaggartauthorMichael Hamiltonauthor2006-01-01As sensor networks become widely deployed in ecological settings, imaging is increasingly becoming an integral component of the system. Often, ecologists are interested in meta-information about the content of these images, rather than the images themselves. This information is at least tedious, and sometimes completely impractical, to extract manually. We will discuss our experiences with images from two deployments at the James Reserve: the existing minirhizotron systems (with an eye toward the upcoming AMARRS), and the nestbox cameras.publicAdventures in Automating Ecological Image Analysis (TER 3)articlelocaloai:escholarship.org:ark:/13030/qt6cj5v6p92011-07-03T16:25:29Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6cj5v6p9Dohyun KimauthorIra B. GoldbergauthorMichael GlickmanauthorJack W. Judyauthor2006-01-01A highly sensitive and miniaturized amperometric nitrate sensor for groundwater monitoring was successfully designed, fabricated, and tested. The silver sensing electrodes were patterned on the silicon substrate with microfabrication techniques. The sensor was thoroughly characterized and the performance is very promising. A low detection limit of 4 ,#61549;M, wide dynamic range of 10000 ,#61549;M with excellent linearity (r2=0.99), and a good selectivity (13.9 % increase in signal for 400% increase of interfering ion concentration) were achieved and yet sensor is in a small form factor (4��×4��×3 cm without electronics). Many efforts have been being made to improve the sensor reliability and operational lifetime, such as including polymer-coated Ag/AgCl reference electrode. To enable real-time field measurements, a sample-preparation system, an automated sample-handing system, and a micropotentiostat with built-in pumps and valves controller have also been studied. In order to overcome limited life-time of the thin-film working electrode, a palm-sized sensor system that consists of macro-scale commercial electrodes, Plexiglass housing, built-in microfluidic channels, and anion-permeable membrane, have been developed.publicA High-Performance Micromachined Amperometric Nitrate Sensor for Environmental Monitoring (SEN 8)articlelocaloai:escholarship.org:ark:/13030/qt9k66k6mx2011-07-03T16:25:24Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9k66k6mxDave CaronauthorDeborah EstrinauthorAri RequichaauthorGaurav Sukhatme; Mrinal MahapatroauthorCarl ObergauthorBeth Stauffer; Amit DhariwalauthorAlex LeeauthorEric ShiehauthorBin Zhang; USC/UCLAauthor2005-01-01publicAQU0: CENS Aquatic Research: Overviewarticlelocaloai:escholarship.org:ark:/13030/qt7285862h2011-07-03T16:25:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7285862hYeonjeong ParkauthorJuyoul KimauthorJose SaezauthorThomas C. Harmonauthor2005-01-01An issue associated with agricultural irrigation using reclaimed wastewater is the potential threat to underlying groundwater quality. A prime example is nitrate, which serves as a fertilizing agent but has the potential to leach into groundwater. In order to balance water reuse and groundwater protection, intelligent irrigation monitoring and management systems are required to manage water reuse. In this work, a wirelessly networked sensor array is being designed for deployment at an agricultural research plot. The sensor array is coupled to a simulation and management algorithm to optimize irrigation scheduling.publicCON2: Management of Soil Moisture and Nitrate Transport Using Sensor Networks and Feedback Controlarticlelocaloai:escholarship.org:ark:/13030/qt5tv6d5s22011-07-03T16:25:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5tv6d5s2J. Eric HauxauthorJohn EwartauthorTom SchoellhammerauthorNaim BusekauthorDeborah EstrinauthorThomas C. Harmonauthor2005-01-01Wireless sensor arrays for observing soil properties would be extremely useful in support of many precision agriculture, environmental monitoring, and terrestrial habitat observation applications. This effort describes the fabrication and functionality of CENS’�¡�Çs aggregate subterranean sensing stations referred to as soil pylons. The specific system described here includes the following sensing modalities: soil moisture, temperature, above-ground precipitation/irrigation rate and aqueous nitrate concentrations. This pylon is being deployed in the context of an wastewater recycling/precision agriculture application.publicCON1: Development of the Soil Pylon System for Observing Subterranean Processesarticlelocaloai:escholarship.org:ark:/13030/qt7z85n9022011-07-03T16:25:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7z85n902Thomas C. HarmonauthorJennifer JayauthorDeborah EstrinauthorJose SaezauthorWilliam KaiserauthorSteve MargulisauthorMiodrag Potkonjak; J. Eric HauxauthorJason FisherauthorJuyoul KimauthorMohammad RahimiauthorNaim BusekauthorJohn EwartauthorYeojeong ParkauthorNithya RamanathanauthorTom Schoellhammerauthor2005-01-01publicCON0: CENS Contaminant Transport Observation and Management Research: Overviewarticlelocaloai:escholarship.org:ark:/13030/qt3c79853s2011-07-03T16:25:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3c79853sMichael HamiltonauthorEric GrahamauthorDeborah EstrinauthorPhil RundelauthorMichael AllenauthorBill KaiserauthorBill SwensonauthorMichael WimbrowauthorMichael TaggartauthorVanessa Rivera Del RioauthorRichard GuyauthorSean Askayauthor2005-01-01publicTER0: Overview Poster: Terrestrial Ecology Observing Systems at the James Reservearticlelocaloai:escholarship.org:ark:/13030/qt5qf724x32011-07-03T15:43:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5qf724x3Ameesh PandyaauthorGreg Pottieauthor2003-01-01Prior results have shown that for ad hoc networks with uniform source-destination probabilities, where each node generates trafc, the transport capacity for each node in the network declines with the network size n [1]. In this paper, we show that the nite per-node throughput and hence scalability is achievable with the adjustment of source-destination pair distributions. We also explore the rate-distortion bound in the context of sensor networks. Considering a network over a nite region, with nite Gaussian point sources and densely distributed sensors, the otherwise difcult to obtain data rate region under a delity criterion, reduces to a partial side information problem for Gaussian sources. The key concept in proving this is to consider source, sensor, and communications relay densities as separate quantities.publicOn Scalability and Source/Channel Coding Decoupling in Large Scale Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt6t24x5xx2011-07-03T15:06:41Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6t24x5xxThomas HarmonauthorChih-Ming HoauthorJack W. JudyauthorYu-Chong Tai; Ira GoldbergauthorTatyan BendikovauthorDohyun KimauthorArnaud BenahmedauthorQing Heauthor2005-01-01publicSEN0: CENS Sensor Research: Overviewarticlelocaloai:escholarship.org:ark:/13030/qt9cp530k42011-07-03T15:06:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9cp530k4Cathy KongauthorRichard PonauthorMohammed RahimiauthorBill KaiserauthorMark HansenauthorGreg PottieauthorGaurav SukhatmeauthorDeborah Estrinauthor2005-01-01In this poster, two major strategies for sampling phenomena with high rate of spatiotemporal variation, namely, multiscale sampling and adaptive sampling, are presented. Multiscale sampling is based on the hypothesis that a combination of sparse sensing along with auxiliary multiscale/multimode sensing will yield accuracy approaching exhaustive sampling. Adaptive sampling is a feature based sampling technique. Algorithms and simulation results for both techniques are demonstrated.publicACT6: Strategies for Sampling the Environmentarticlelocaloai:escholarship.org:ark:/13030/qt1ws825zq2011-07-03T15:06:16Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1ws825zqRichard PonauthorLisa ShirachiauthorBill Kaiserauthor2005-01-01Rapidly growing stress on the natural environment has created an urgent demand for new environmental exploration systems that operate remotely and autonomously. As sensor networks are applied to this critical environmental monitoring problems, a series of new requirements have emerged for extensive characterization of dynamic phenomena in three-dimensional environments. The unpredictable presence of obstacles to sensing and the inherent temporal evolution of events create limitations for optimal deployment of sensors in the environment. Networked Infomechanical Systems (NIMS) technology has been developed to introduce precise and sustainable actuation for distributed sensing.publicACT5: Networked Infomechanical Systemsarticlelocaloai:escholarship.org:ark:/13030/qt5ck1f0h42011-07-03T15:06:07Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5ck1f0h4Dohyun KimauthorIra B. GoldbergauthorJack W. Judyauthor2005-01-01publicA High A High-Performance Performance Micromachined Micromachined Amperometric Amperometricarticlelocaloai:escholarship.org:ark:/13030/qt6sj0b1d62011-07-03T15:06:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6sj0b1d6Dohyun KimauthorIra B. GoldbergauthorJack W. Judyauthor2005-01-01publicA High-performance Micromachined Amperometric Nitrate Sensor for Environmental Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt9bn253ck2011-07-03T15:05:57Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9bn253ckAmeesh PandyaauthorAman KansalauthorGreg PottieauthorMani Srivastavaauthor2003-01-01We consider the network information theoretic problem of finding the rate distortion bound for separate coding of multiple correlated sources. First, we find the outer region for separate coding with distortion when only one of the sources is to be reproduced and the other sources are used as helpers. We then find the outer region for separate coding when all the sources are to be reproduced with specified distortions. The rate distortion bounds have previously been calculated for two correlated sources. We find an inductive approach to consider several sources one after the other to derive the general result. We also show the practical implications of our work for several implementations. Our results can be directly utilized by designers to choose not only how many of the available sources should actually be coded but also which sources have the highest potential to reduce the distortion.publicCollaborative Data Compression in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt06k6p7pz2011-07-03T15:05:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/06k6p7pzAmit DhariwalauthorGaurav SukhatmeauthorAri RequichaauthorDavid Caronauthor2003-01-01The poster presents a very simple approach for source and boundary detection using biased random walks (inspired from bacterial motion) which could be a novel strategy for robotic sensor network problems.publicBacteria-Inspired Motion Strategies for Robotic Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt8q70p81g2011-07-03T14:39:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8q70p81gPark, YeonjeongauthorShamma, JeffauthorHarmon, Thomas Cauthor2009-02-01The capacity to adaptively manage irrigation and associated contaminant transport is desirable from the perspectives of water conservation, groundwater quality protection, and other concerns. This paper introduces the application of a feedback-control strategy known as Receding Horizon Control (RHC) to the problem of irrigation management. The RHC method incorporates sensor measurements, predictive models, and optimization algorithms to maintain soil moisture at certain levels or prevent contaminant propagation beyond desirable thresholds. Theoretical test cases are first presented to examine the RHC scheme performance for the control of soil moisture and nitrate levels in a soil irrigation problem. Then, soil moisture control is successfully demonstrated for a center-pivot system in Palmdale, CA where reclaimed water is used for agricultural irrigation. Real-time soil moisture, temperature, and meteorological data are streamed wirelessly to a field computer to enable autonomous execution of the RHC algorithm. The RHC scheme is demonstrated to be a viable strategy for achieving water reuse and agricultural objectives while minimizing negative impacts on environmental quality.publicContaminant Transportsoil sensorsirrigationfeedback-controlA Receding Horizon Control Algorithm for Adaptive Management of Soil Moisture and Chemical Levels during Irrigationarticlelocaloai:escholarship.org:ark:/13030/qt77r2j6p02011-07-03T14:37:17Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/77r2j6p0Estrin, Dauthor2007-01-01This paper presents different applications of wireless sensing systems in environmental sensing and sensing in everyday life.publicReflections on Wireless Sensing Systems: From Ecosystems to Human Systemsarticlelocaloai:escholarship.org:ark:/13030/qt8d0845882011-07-03T14:34:51Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8d084588M. BatalinauthorG. S. Sukhatmeauthor2004-01-01publicCoverage, Exploration and Deployment by a Mobile Robot and Communication Networkarticlelocaloai:escholarship.org:ark:/13030/qt63g6k6qx2011-07-03T14:33:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/63g6k6qxNiles J. HasselquistauthorAllen, Edith BauthorAllen, Michael F.author2006-01-11Seasonal tropical forests are currently experiencing rapid deforestation and changing land management practices, which in turn may permanently transform mature forests into more shrub-herbaceous dominated plant communities and planted pastures. Effective restoration efforts are therefore essential for maintaining the biodiversity and ecosystem functioning in seasonal tropical forests, yet before implementing restoration efforts we need to better understand mechanisms influencing secondary plant succession. The main objective of this study was to investigate the ecological significance mycorrhizae, the symbiotic association between plant roots and specific fungi, may have during secondary plant succession. In 2004, we selected a chronosequence of five distinct stages of secondary succession ranging from recently disturbed areas to more mature forest at El Eden Ecological Reserve in northeastern Yucatan. We determined the plant community composition, as well as, the percent vesicular-arbuscular mycorrhizae (VAM) colonization and VAM spore diversity for each of the distinct stages of succession. Based on preliminary data we found a relatively low Sorenson index for plant species composition among the different stages (0.24-0.430) compared to within specific stages (0.50- 0.789), suggesting that plant communities are changing during secondary succession. On the other hand, we detected no significant difference in vesicular-arbuscular mycorrhizal (VAM) infection among the chronosequence, with an overall average infection of 16.94%. Nevertheless, we did observe a change in VAM species from small-spored Glomus species in earlier stages of succession to larger-spored Gigaspora and Acaulospora species as the forest matures. It therefore appears that in order to maintain the biodiversity and ecosystem functioning of seasonal tropical forest attention must also be give to below ground processes such as mycorrhizal fungi.publicTerrestrialThe Influence of Vesicular-Arbuscular Mycorrhizae During Secondary Plant Succession in a Seasonal Tropical Forestarticlelocaloai:escholarship.org:ark:/13030/qt94h847x92011-07-03T14:32:17Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/94h847x9Savvides, AndreasauthorPark, HeeminauthorSrivastava, Mani B.author2002-09-28The recent advances in MEMS, embedded systems and wireless communication technologies are making the realization and deployment of networked wireless microsensors a tangible task. Vital to the success of wireless microsensor networks is the ability of microsensors to “collectively perform sensing and computation”. In this paper, we study one of the fundamental challenges in sensor networks, node localization. The collaborative multilateration presented here, enables ad-hoc deployed sensor nodes to accurately estimate their locations by using known beacon locations that are several hops away and distance measurements to neighboring nodes. To prevent error accumulation in the network, node locations are computed by setting up and solving a global non-linear optimization problem. The solution is presented in two computation models, centralized and a fully distributed approximation of the centralized model. Our simulation results show that using the fully distributed model, resource constrained sensor nodes can collectively solve a large non-linear optimization problem that none of the nodes can solve individually. This approach results in significant savings in computation and communication, that allows fine-grained localization to run on a low cost sensor node we have developed.publicMultiscaled Actuated SensingAd-Hoc LocalizationDistributed LocalizationSensor NetworksThe Bits and Flops of the N-hop Multilateration Primitive for Node Localization Problemsarticlelocaloai:escholarship.org:ark:/13030/qt906314cv2011-07-03T14:31:38Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/906314cvLewis GirodauthorMartin LukacauthorAndrew ParkerauthorThanos StathopoulosauthorJeffrey TsengauthorHanbiao WangauthorDeborah EstrinauthorRichard GuyauthorEddie Kohlerauthor2005-01-01publicA Reliable Multicast Mechanism for Sensor Network Applicationsarticlelocaloai:escholarship.org:ark:/13030/qt0dh6p44g2011-07-03T14:28:45Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0dh6p44gJ. ZhaoauthorS. AsgariauthorC.E. ChenauthorA.M. AliauthorR.E. HudsonauthorK. YaoauthorE. Tacirogluauthor2006-01-01This poster describes our work on sensor array processing for the purpose of source localization with seismic signals. Methods for event detection, source direction of arrival (DOA) estimation, and source localization via DOA estimates are presented with results.publicSensor Array Processing for Seismic Source Localization (SYS 23)articlelocaloai:escholarship.org:ark:/13030/qt6tf8q6kc2011-07-03T14:28:18Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6tf8q6kcLeyla SabetauthorArnaud BenahmedauthorChih-Ming Hoauthor2006-01-01publicUltra Sensitive Laser Induced Fluorescence Sensor (SEN 4)articlelocaloai:escholarship.org:ark:/13030/qt7zj817c82011-07-03T14:28:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7zj817c8Jason FisherauthorHenry PaiauthorThomas Harmon (UC Merced); Amarjeet SinghauthorMaxim A. BatalinauthorMichael StealeyauthorVictor ChenauthorWilliam Kaiser (UCLA)author2006-01-01In order to understand and control the impact of non-point source pollution in Central California and many semi-arid regions of the world, a multiscale observational network focused on several water quality issues is proposed. Specifically, we are targeting the main stem of the San Joaquin River as a prototypical river system. By developing multiscale modeling approaches, we will endeavor first to understand the hydrodynamics of salt mixing on the San Joaquin at each of the three river confluences (with the Merced, Tuolumne, and Stanislaus Rivers) and create salt-flow rating curves characterizing 5 different flow conditions, and second, to quantify and sample groundwater-surface water interactions along critical reaches of the river where the US Geological Survey is investigating with respect to groundwater accretion.publicUnderstanding of Flow, Mixing, and Groundwater Accretion on Large-Scale Rivers Using Integrated Modeling and Multiscale embedded Networked Sensing (CON 4)articlelocaloai:escholarship.org:ark:/13030/qt2t72v6nt2011-07-03T14:27:16Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2t72v6ntAmit DhariwalauthorBin ZhangauthorEric ShiehauthorBeth StaufferauthorCarl ObergauthorDavid CaronauthorAristides RequichaauthorGaurav Sukhatmeauthor2005-01-01There is a need to provide a platform for better monitoring and sampling in Marine environments. Such a platform should be able to withstand the highly dynamic nature of such an environment as well as cope with its vastness. The platform should be simple and easily scalable. A platform of this type would provide the scientists an invaluable tool in order to further the marine research by monitoring phenomena of biological importance. As part of our research, we are building a fleet of autonomous roboducks (robotic air boats) for in-situ operation (data collection and analysis: using the stargate platform) in marine environments. The platform would support a variety of sensor suites and at the same time be easy to operate.publicACT4: Networked Aquatic Sampling Systemarticlelocaloai:escholarship.org:ark:/13030/qt1v08b6672011-07-03T14:26:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1v08b667William SwensonauthorRodrigo VargasauthorMike TaggartauthorChris GloverauthorMichael HamiltonauthorMichael F. Allenauthor2005-01-01publicAMARSS: Identifying meaningful spatial and temporal scales for measuring ecological processes in soilarticlelocaloai:escholarship.org:ark:/13030/qt0fs0f24f2011-07-03T14:25:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0fs0f24fNarayanan SadagopanauthorBhaskar KrishnamachariauthorHelauthor2003-01-01We propose a novel and efficient mechanism for obtaining information in sensor networks which we refer to as acquire. In acquire an active query is forwarded through the network, and intermediate nodes use cached local information (within a look-ahead of d hops) in order to partially resolve the query. When the query is fully resolved, a completed response is sent directly back to the querying node. We take a mathematical modeling approach to calculate the energy costs associated with acquire. The models permit us to characterize analytically the impact of critical parameters, and compare the performance of acquire with respect to alternatives such as flooding-based querying (FBQ) and expanding ring search (ERS). We show that with optimal parameter settings, depending on the update frequency, acquire obtains order of magnitude reduction over FBQ and a potential reduction of 60% over ERS in consumed energy.publicThe Acquire Mechanism for Efficient Querying in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt6fs4559s2011-07-03T14:23:40Z am 3u Center for Embedded Network SensingVol. 7, no. 1–2 (Nov. 2006) 17-30eScholarship, University of Californiahttps://escholarship.org/uc/item/6fs4559sBorgman, C LauthorWallis, J CauthorEnyedy, Nauthor2006-11-25e-Science promises to increase the pace of science via fast, distributed access to computational resources, analytical tools, and digital libraries. “Big science” fields such as physics and astronomy that collaborate around expensive instrumentation have constructed shared digital libraries to manage their data and documents, while “little science” research areas that gather data through hand-crafted fieldwork continue to manage their data locally. As habitat ecology researchers begin to deploy embedded sensor networks, they are confronting an array of challenges in capturing, organizing, and managing large amounts of data. The scientists and their partners in computer science and engineering make use of common datasets but interpret the data differently. Studies of this field in transition offer insights into the role of digital libraries in e-Science, how data practices evolve as science becomes more instrumented, and how scientists, computer scientists, and engineers collaborate around data. Among the lessons learned are that data on the same variables are gathered by multiple means, that data exist in many states and in many places, and that publication practices often drive data collection practices. Data sharing is embraced in principle but little sharing actually occurs, due to interrelated factors such as lack of demand, lack of standards, and concerns about publication, ownership, data quality, and ethics. We explore the implications of these findings for data policy and digital library architecture. Research reported here is affiliated with the Center for Embedded Networked Sensing.publicStatistics and Data PracticesLittle Science Confronts the Data Deluge: Habitat Ecology, Embedded Sensor Networks, and Digital Librariesarticlelocaloai:escholarship.org:ark:/13030/qt3v00c6982011-07-03T14:23:30Z am 3u Center for Embedded Network SensingVol. 32, no. 6 (Nov. 2006) 929-937eScholarship, University of Californiahttps://escholarship.org/uc/item/3v00c698Stafsudd, J.ZauthorAsgari, ShadnazauthorChen, Chiao-EnauthorHudson, Ralph E.authorLorenzelli, F.authorYao, KauthorTaciroglu, Ertugrulauthor2006-11-20In this paper, we consider the analysis, implementation, and application of wideband sources using both seismic and acoustic sensors. We use the approximate maximum likelihood (AML) algorithm to perform acoustic direction of arrival (DOA). For non-uniform noise spectra, whitening filtering was applied to the received acoustic signals before the AML operation. For short-range seismic DOA applications, one method was based on eigen-decomposition of the covariance matrix and a second method was based on surface wave analysis. Two well-known optimization schemes were used to estimate the source locations from the estimated DOAs at sensors of known locations. Experimental estimation of the DOAs and resulting localizations using the acoustic and seismic signals generated by striking a heavy metal plate by a hammer were reported.publicMultiscaled Actuated Sensingacoustic arrayseismic arraybeamformingDOAlocalizationAnalysis, Implementation, and Application of Acoustic and Seismic Arraysarticlelocaloai:escholarship.org:ark:/13030/qt6tc5w7zf2011-07-03T14:22:50Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6tc5w7zfJohn ProbstauthorAllen HuskerauthorIgor StubailoauthorMonica KohlerauthorPaul Davisauthor2004-01-01The Seismic Applications group is working to increase the practical limits of the density of seismic deployments and move to more rapid data gathering in temporary deployments. Temporary deployments in seismology typically consist of stand-alone sites in order to decrease installation time. Data must be collected either periodically from each site or at the end of the experiment and incorporated into a data base for analysis. Permanent seismic installations do transmit data immediately to central data bases through ethernet, point-to-point radio, and modem. We add the ’¡Èreal-time’¡É data collection of permanent installations to temporary networks with multi-hop networking. Off-the-shelf 802.11 wireless radio cards are incorporated with an Intel Stargate computer running Roofnet networking software. In-house software is developed to collect data and route it hop-by-hop through the network to a central data repository. Hop-by-hop data movement allows data to pass effectively through the radio network despite breaks or flaky links within the network.publicSeismic Networkarticlelocaloai:escholarship.org:ark:/13030/qt9ff9w4pm2011-07-03T14:22:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9ff9w4pmStasa MilojevicauthorKalpana ShankarauthorChristine Borgmanauthor2003-01-01CENS is producing a vast and rich array of scientific and technical data. Ensuring accessibility and maintaining the integrity of those data is essential for the research and educational efforts of CENS participants and future users of CENS data. The nature of CENS data and the heterogeneity of its users present a number of information and data management challenges. We need to understand better how to collect, organize, access, and preserve scientific data so that they are useful for multiple users having different level of subject expertise and with multiple purposes for use. To do so will require studying current practices and information needs of CENS users, developing user scenarios, and investigating standards, tools, and policies for scientific data, metadata, and information management. Here we present our current research and plans for the future. Our goal is for CENS to become a leader in the implementation of standards and technologies for multidisciplinary data and sensor network portals.publicMaking CENS Data Useful And Usablearticlelocaloai:escholarship.org:ark:/13030/qt74h0v84v2011-07-03T14:22:11Z am 3u Center for Embedded Network SensingVol. 36, no. 5 (Jan. 2006) 619-639eScholarship, University of Californiahttps://escholarship.org/uc/item/74h0v84vYu, EunjongauthorTaciroglu, ErtugrulauthorWallace, J Wauthor2006-01-01In this study, we formulate an improved finite element model-updating method to address the numerical difficulties associated with ill conditioning and rank deficiency. These complications are frequently encountered model-updating problems, and occur when the identification of a larger number of physical parameters is attempted than that warranted by the information content of the experimental data. Based on the standard bounded variables least-squares (BVLS) method, which incorporates the usual upper/lower-bound constraints, the proposed method (henceforth referred to as BVLSrc) is equipped with novel sensitivity-based relative constraints. The relative constraints are automatically constructed using the correlation coefficients between the sensitivity vectors of updating parameters. The veracity and effectiveness of BVLSrc is investigated through the simulated, yet realistic, forced-vibration testing of a simple framed structure using its frequency response function as input data. By comparing the results of BVLSrc with those obtained via (the competing) pure BVLS and regularization methods, we show that BVLSrc and regularization methods yield approximate solutions with similar and sufficiently high accuracy, while pure BVLS method yields physically inadmissible solutions. We further demonstrate that BVLSrc is computationally more efficient, because, unlike regularization methods, it does not require the laborious a priori calculations to determine an optimal penalty parameter, and its results are far less sensitive to the initial estimates of the updating parameters. Copyright © 2006 John Wiley & Sons, Ltd.publicSeismicsystem identificationmodel updatingforced-vibration testingParameter Identification of Framed Structures Using an Improved Finite Element Model Updating Method—Part I: Formulation and Validationarticlelocaloai:escholarship.org:ark:/13030/qt8zx0j3jk2011-07-03T14:21:53Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8zx0j3jkYang, Lung-JiehauthorYao, Tze-JungauthorHuang, Yu-LinauthorXu, YongauthorTai, Yu-Chongauthor2002-01-20This paper describes a new method and an analytical model for characterizing the surface energy inside a microchannel using the measurement of the marching velocity of a capillary meniscus. This method is based on the fact that surface tension of a liquid meniscus in a hydrophilic case produces pressure to pull liquid into the channel and the velocity of the meniscus is related to the surface energy. Both Parylene and silicon nitride microchannels with different surface conditions were fabricated to perform the liquid-filling experiments. It is shown that our model agrees well with the data and this is a valid method.publicSensorscapillaritysurface energysurface tensionMarching Velocity of Capillary Meniscuses in Microchannelsarticlelocaloai:escholarship.org:ark:/13030/qt9bp577932011-07-03T14:20:43Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9bp57793Gnawali, OmprakashauthorGreenstein, BenauthorJang, Ki-YoungauthorJoki, AugustauthorPaek, JeongyeupauthorVieira, MarcosauthorEstrin, DauthorGovindan, RameshauthorKohler, Eddieauthor2006-11-01Most sensor network research and software design has been guided by an architectural principle that permits multi-node data fusion on small-form-factor, resource-poor nodes, or motes. We argue that this principle leads to fragile and unmanageable systems and explore an alternative. The Tenet architecture is motivated by the observation that future largescale sensor network deployments will be tiered, consisting of motes in the lower tier and masters, relatively unconstrained 32-bit platform nodes, in the upper tier. Masters provide increased network capacity. Tenet constrains multinode fusion to the master tier while allowing motes to process locally-generated sensor data. This simplifies application development and allows mote-tier software to be reused. Applications running on masters task motes by composing task descriptions from a novel tasklet library. Our Tenet implementation also contains a robust and scalable networking subsystem for disseminating tasks and reliably delivering responses.We show that a Tenet pursuit-evasion application exhibits performance comparable to a mote-native implementation while being considerably more compact.publicsensor networksnetwork architecturemotesThe Tenet Architecture for Tiered Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt75z962742011-07-03T14:19:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/75z96274Deepak GanesanauthorRazvan CristescuauthorBaltasar Beferull-Lozanoauthor2003-01-01We consider the joint optimization of sensor placement and transmission structure for data gathering, where a given number of nodes need to be placed in a field such that the sensed data can be reconstructed at a sink within specified distortion bounds while minimizing the energy consumed for communication.publicPower-Efficient Sensor Placement and Transmission Structure for Data Gathering under Distortion Constraintsarticlelocaloai:escholarship.org:ark:/13030/qt8r1758662011-07-03T14:16:29Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8r175866Graham, EricauthorHicks, JohnauthorRiordan, ErinauthorWang, EricauthorYuen, Ericauthor2009-05-12Stationary and mobile ground-based cameras can be used to scale ecological observations, relating pixel information in images to in situ measurements. Currently there are four CENS projects that involve using cameras for scaling ecological observations: 1. Scaling from one individual to the landscape. Pan-Tilt-Zoom cameras can be zoomed in on a tight focus on individual plants and parts of individuals and then zoomed out to get a landscape view, composed of the same and similar species. 2. Estimating photosynthesis over large areas with HDR. High Dynamic Range imaging is a technique to capture an absolute amount of reflected light in an image. For a meadow composed of similarly reflecting species, we can estimate light received by leaves and thus photosynthesis over a wide area. 3. Scaling soil surface temperature measurements. Soil surface temperatures and soil energy balance are related to solar radiation and air temperature. Sunflecks captured with a camera taking panoramic mosaics of images can be used to estimate the radiation load for large areas of unobstructed understory. 4. Expanding plant phenological observations with a nation-wide network of webcams. Twice-daily images from over 1000 internet-connected and freely available cameras have been collected since February 2008. The advance of Spring can be tracked as a "green-up" and related to satellite remote sensing signals.publicTerrestrialUsing Imagers for Scaling Ecological Observationsarticlelocaloai:escholarship.org:ark:/13030/qt3538q0g02011-07-03T14:15:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3538q0g0Beth StaufferauthorStefanie MoorthiauthorBin ZhangauthorAmit DhariwalauthorCarl ObergauthorArvind PereiraauthorDavid CaronauthorGaurav Sukhatmeauthor2006-01-01The Networked Aquatic Microbial Observing System (NAMOS) is an array of embedded networked sensors that has been developed to study plankton populations in marine and aquatic environments. The application of NAMOS in Lake Fulmor, adjacent to the James Mountain Reserve, California, has begun to yield valuable insights into plankton community structure and dynamics, including phytoplankton spatial and temporal distributions throughout the lake. Data collected during deployments of the system in May, July, and October, 2005 revealed decreases in water column temperature stratification, accompanied by overall increases in chlorophyll in the lake throughout the three deployments. Chlorophyll concentrations (indicative of phytoplankton biomass) exhibited strong diel variations at a depth of one meter, with highest concentrations during the evening and early morning (18:00-06:00) and much lower values during the day. These findings presumably indicate a strong vertical migratory behavior of the phytoplankton assemblage.publicAQU 1: Characterization of the Phytoplankton Community in Lake Fulmor, CA, Using Embedded Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt2vv078qh2011-07-03T14:13:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2vv078qhN. RamanathanauthorL. GirodauthorE. KohlerauthorD. Estrinauthor2005-01-01publicSympathy: A Debugging System for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt34b2t2f52011-07-03T14:13:03Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/34b2t2f5B. FulkersonauthorS. SoattoauthorW. SwensonauthorM. AllenauthorM. Hamiltonauthor2005-01-01The ability to do robust, meaningful research with minirhizotron images is currently limited by the amount of time that can be spent by a human expert classifying the data. This poster focuses on presenting a path towards automated analysis of these images. It shows preliminary results from two off-the-shelf vision algorithms, which suggest that further research needs to be done.publicSIP4: Towards Automated Analysis of Minirhyzotron Imagesarticlelocaloai:escholarship.org:ark:/13030/qt9bf7f3n52011-07-03T14:11:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9bf7f3n5Jeongyeup PaekauthorNupur KothariauthorKrishna ChintalapudiauthorSumi RangwalaauthorRamesh Govindanauthor2004-01-01An issue associated with agricultural irrigation using reclaimed wastewater is the potential threat to underlying groundwater quality. A prime example is nitrate, which serves as a fertilizing agent but has the potential to leach into groundwater. In order to balance water reuse and groundwater protection, intelligent irrigation management and monitoring systems are required for such water reuse systems. In this work, a nonlinear programming-based control algorithm is proposed to optimize irrigation scheduling subject to contaminant transport constraints. In support of the algorithmic developments, a networked sensor array is being designed for deployment at an agricultural research plot. This array will supply real-time field information about water infiltration and distribution, nitrate propagation, and heat transport, to the irrigation scheduling algorithm. The control scheme (measurement, decision, and action) will be continuously updated using on-line feedback from sensors. The simulator on which the management algorithm depends is a one-dimensional form of the Richards equation coupled to energy and solute transport mass balances.publicThe Performance of a Wireless Sensor Network for Structural Health Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt8ps6g3vp2011-07-03T14:11:49Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8ps6g3vpHuiyu LuoauthorGreg Pottieauthor2004-01-01We study the correlated information routing with source coding using explicit side information in wireless sensor networks. This problem belongs to the difficult joint compression/routing optimization, and has its connections to the network information theory. We present our network and rate models based on explicit side information available at both the encoder and decoder, then introduce the integer programming formulation with a few simplifying assumptions. A two-stage DPCM coding scheme that can take advantage of the explicit side information and report the additional spatial is also included.publicCorrelated Data Routing in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt4948t1w42011-07-03T14:11:44Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4948t1w4Juyoul KimauthorJose SaezauthorNaim BusekauthorYeonjeong ParkauthorJ. Eric HauxauthorDeborah EstrinauthorThomas Harmonauthor2004-01-01An issue associated with agricultural irrigation using reclaimed wastewater is the potential threat to underlying groundwater quality. A prime example is nitrate, which serves as a fertilizing agent but has the potential to leach into groundwater. In order to balance water reuse and groundwater protection, intelligent irrigation management and monitoring systems are required for such water reuse systems. In this work, a nonlinear programming-based control algorithm is proposed to optimize irrigation scheduling subject to contaminant transport constraints. In support of the algorithmic developments, a networked sensor array is being designed for deployment at an agricultural research plot. This array will supply real-time field information about water infiltration and distribution, nitrate propagation, and heat transport, to the irrigation scheduling algorithm. The control scheme (measurement, decision, and action) will be continuously updated using on-line feedback from sensors. The simulator on which the management algorithm depends is a one-dimensional form of the Richards equation coupled to energy and solute transport mass balances.publicNetworked Sensing of Nitrate in Support of Groundwater Quality Protectionarticlelocaloai:escholarship.org:ark:/13030/qt3db3d6442011-07-03T14:11:38Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3db3d644Dohyun KimauthorIra GoldbergauthorJack Judyauthor2004-01-01A nitrate-sensing system that consists of a micromachined sensor substrate, nitrate-permeable membrane, integrated microfluidic channels, and standard fluidic connectors has been designed, fabricated, assembled, and tested. Our microsensor was designed for in-situ monitoring of nitrate concentrations in ground water. A silver electrode was patterned for amperometric nitrate detection. An electrochemically oxidized silver electrode was used as a reference electrode. Microfluidic channels were fabricated as flow paths for the eluent and ground-water sample to the microelectrochemical (MEC) cell. The sensor also incorporates an anion-permeable membrane that is used for selective measurement of nitrate. With standard addition methods, linear calibration curves (1NlM to 1 mM) are obtained for several sensing chips. We observed that the sensor output increased only 13.9 %, even though a 100NlM nitrate sample solution contains interfering ions of the same concentration (100NlM each of PO 4-2, SO4-3, F-, Cl-).publicMicromachined Amperometric Nitrate Sensorarticlelocaloai:escholarship.org:ark:/13030/qt2wx271882011-07-03T14:11:17Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2wx27188Lewis GirodauthorThanos StathopoulosauthorNithya RamanathanauthorEric OsterweilauthorTom SchoellhammerauthorR. KapurauthorDeborah Estrinauthor2004-01-01Recently deployed Wireless Sensor Network systems (WSNs) are increasingly following {\em heterogeneouspublicEmTOS: A Development Tool for Heterogeneous Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt25p5w88n2011-07-03T14:11:11Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/25p5w88nSaurabh GaneriwalauthorMani B. Srivastavaauthor2004-01-01The traditional approach of providing network security has been to borrow tools from cryptography and authentication. However, we argue that the conventional view of security based on cryptography alone is not sufficient for the unique characteristics and novel misbehaviors encountered in sensor networks. Fundamental to this is the observation that cryptography cannot prevent malicious or non-malicious insertion of data from internal adversaries or faulty nodes. We believe that in general tools from different domains such as economics, statistics and data analysis will have to be combined with cryptography for the development of trustworthy sensor networks. Following this approach, we propose a reputation-based framework for sensor networks where nodes maintain reputation for other nodes and use it to evaluate their trustworthiness. The framework is modularized; we will analyze each building block in detail in this paper. We will show that this framework provides a scalable, diverse and a generalized approach for countering all types of misbehavior resulting from malicious and faulty nodes.publicReputation-Based Frameworks for High Integrity Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt08z378g12011-07-03T14:10:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/08z378g1Bianauthor2004-01-01Until practical ad-hoc localization systems are developed, early deployments of wireless sensor networks will manually configure location information in network nodes in order to assign spatial context to sensor readings. In this paper, we argue that such deployments will use hierarchical location names (for example, a node in a habitat monitoring network might be said to be node number N in cluster C of region R), rather than positions in a two- or three-dimensional coordinate system. We show that these hierarchical location names can be used to design a scalable routing system called HLR. HLR provides a variety of primitives including unicast, scoped anycast and broadcast, as well as various forms of scalable rendezvous. These primitives can be used to implement most data-centric routing and storage schemes proposed in the literature; these schemes currently need precise position information and geographic routing in order to scale well. We evaluate HLR using simulations as well as an implementation on the Mica-2 motes.publicUsing Hierarchical Location Names for Scalable Routing and Rendezvous in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt60z050qn2011-07-03T14:10:37Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/60z050qnAlberto CerpaauthorJennifer WongauthorLouane KuangauthorMiodrag PotkonjakauthorDeborah Estrinauthor2004-01-01Recently, several landmark wireless sensor network deployment studies clearly demonstrated a great discrepancy between experimentally observed communication properties and properties produced by widely used simulation models. Our first goal is to provide sound foundations for conclusions drawn from these studies by extracting the relationship between pairs of location (e.g distance) and communication properties (e.g. reception rate) using non-parametric statistical techniques and by calculating intervals of confidence for all claims. Furthermore, we study not only individual links properties, but also their correlation with respect to common transmitters and receivers and their geometrical location. The second and main objective is to develop a series of wireless network generators which produce networks of an arbitrary size and under arbitrary deployment rules with realistic communication properties. For this task we use a generalized rejection algorithm and an iterative improvement-based optimization procedure to generate instances of the network that are statistically similar to empirically observed networks. We evaluate the accuracy our conclusions using the proposed model on a set of standard communication tasks, such as connectivity maintenance and routing.publicStatistical Model of Lossy Links in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt3vb8178z2011-07-03T14:10:28Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3vb8178zAlessandro BissaccoauthorJason MeltzerauthorSoheil GhiasiauthorStefano Soattoauthor2004-01-01We present a fast visual feature tracking system which takes advantage of dedicated hardware to perform the computationally intensive step of selection. A software system uses the output of the hardware selector to develop tracks using filtering and data association techniques, and image-based validation. By using separate, custom hardware to select hundreds of points per frame then associating these points to tracks in software, we achieve greater than 60Hz real-time tracking.publicFast Visual Feature Selection and Tracking in a Hybrid Reconfigurable Architecturearticlelocaloai:escholarship.org:ark:/13030/qt4z9444hm2011-07-03T14:10:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4z9444hmMaxim BatalinauthorGaurav SukhatmeauthorWilliam KaiserauthorYan YuauthorRichard PonauthorJason GordonauthorM. H. RahimiauthorGregory J. PottieauthorDeborah Estrinauthor2004-01-01Monitoring of environmental phenomena with embedded networked sensing confronts the challenges of both unpredictable variability in the spatial distribution of phenomena, coupled with demands for a high spatial sampling rate in three dimensions. For example, low distortion mapping of critical solar radiation properties in forest environments may require two-dimensional spatial sampling rates of greater than 10 samples=m2 over transects exceeding 1000 m2. Clearly, adequate sampling coverage of such a transect requires an impractically large number of sensing nodes. A new approach, Networked Infomechanical System (NIMS), has been introduced to combine autonomous-articulated and static sensor nodes enabling sufficient spatiotemporal sampling density over large transects to meet a general set of environmental mapping demands.publicTask Allocation for Event-Aware Spatiotemporal Sampling of Environmental Variablesarticlelocaloai:escholarship.org:ark:/13030/qt9r02g4jq2011-07-03T14:10:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9r02g4jqYuan YaoauthorYing LinauthorHanbiao WangauthorEdward StablerauthorKung YaoauthorCharles Taylorauthor2003-01-01The acorn woodpecker (melanerpes formicivorus) is a highly social species with co-breeding behavior. The vocalization of the acorn woodpecker is thought to be complex due to the complexity of its social system. This research aims to study the vocalization and relevant social behaviors of the acorn woodpecker through various aspects such as the vocal features, the functions of different call types, general patterns of vocal communication, intraspecific /interspecific responses to vocal signals. In the study the distributed wireless sensor network will be applied to collect and monitor the vocal signals of acorn woodpeckers. Furthermore, this system could identify and localize individuals from their calls. After the sensor network is built, the information collected by the network will be used in bioacoustic and behavioral analysis.publicA Study of Vocalization and Social Behavior of the Acorn Woodpecker (Melanerpes Formicivorus) Based on the Remote Sensor Networkarticlelocaloai:escholarship.org:ark:/13030/qt4wb2q9672011-07-03T14:10:04Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4wb2q967Ashutosh VermaauthorWinston WuauthorSridhar VemuriauthorGregory PottieauthorWilliam Kaiserauthor2003-01-01Advances in distributed embedded computing and wireless networking have enabled the first generation of wireless sensor networks for applications including national security, healthcare, and environmental monitoring. Many applications require nodes with continuous vigilance and unattended operations for periods of months to years with only compact energy sources. In this research we are developing the new Smart Object architecture that is based on modular, reconfigurable, hardware components with intelligent interfaces for local power and performance scheduling and for rapid composabilty. It is focused on the development of architectures and modules along with the corresponding standard object oriented software library interfaces, and the implementation of complete open source wireless sensor solutions.publicSmart Object Architecture for Energy-Efficient Wireless Sensorsarticlelocaloai:escholarship.org:ark:/13030/qt9tw3399r2011-07-03T14:09:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9tw3399rNorman Makoto SuauthorHeemin ParkauthorEric BostromauthorJeff BurkeauthorMani B. SrivastavaauthorDeborah Estrinauthor2003-01-01With the advent of tiny networked devices, mark weisers vision of a world embedded with invisible computers is coming to age. Due to their small size and relative ease of deployment, sensor networks have been utilized by zoologists, seismologists and military personnel. In this paper, we investigate the novel application of sensor networks to the film industry. In particular, we are interested in augmenting film and video footage with sensor data. Unobtrusive sensors are deployed on a film set or in a television studio and on performers. During a filming of a scene, sensor data such as light intensity, color temperature and location are collected and synchronized with each film or video frame. Later, editors, graphics artists and programmers can view this data in synchronization with film and video playback. For example, such data can help define a new level of seamless integration between computer graphics and real world photography. A real-time version of our system would allow sensor data trigger camera movement and cue special effects...publicAugmenting Film/Video Footage with Sensor Dataarticlelocaloai:escholarship.org:ark:/13030/qt7bk862xd2011-07-03T14:09:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7bk862xdMohammad RahimiauthorHardik ShahauthorSandeep BabelauthorGuarav SukhatmeauthorJohn HeidemannauthorDeborah Estrinauthor2003-01-01Robomote is a next generation sensor actuator platform to enable mobility in sensor networks. Mobility assisted sensor networks would be able to do things like network repair, balance energy distribution and boundary detection.publicRobomote: Sensor Actuator Platformarticlelocaloai:escholarship.org:ark:/13030/qt25p2k94q2011-07-03T14:09:25Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/25p2k94qSundeep PattemauthorBhaskar KrishnamachariauthorRamesh Gauthor2003-01-01While several data aggregation techniques have been proposed for sensor networks, an understanding of the performance of various data aggregation schemes across the range of spatial correlations is lacking. We analyze the performance of routing with compression in sensor networks using an application-independent measure of data compression (an empirically obtained approximation for the joint entropy of sources as a function of the distance between them) to quantify the size of compressed information, and a bit-hop metric to quantify the total cost of joint routing with compression. Analytical modeling and simulations reveal that while the nature of optimal routing with compression does depend on the correlation level, surprisingly, there exists a static clustering scheme which can provide near-optimal performance for a wide range of spatial correlations. The implication, that there exist relatively simple energy-efficient aggregation schemes for correlated sources has much practical importance.publicThe Impact of Spatial Correlation on Routing with Compression in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt1p24g76m2011-07-03T14:09:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1p24g76mKelli A. MillwoodauthorWilliam A. SandovalauthorJeffery BockertauthorKathy GriffisauthorSara TerheggenauthorJoe WiseauthorChristine Borgmanauthor2003-01-01This study examined how urban high school students beliefs about the nature of professional science relate to their beliefs about school science, with particular focus on ideas about the purpose of experimentation and factors influencing knowledge change. A published questionnaire (VNOS, Lederman et al., 2002) was used to assess students’¡Ç beliefs about professional science, and groups of students were interviewed about an artifact they created from a modeling activity. The interview asked about their perceptions of the purpose of the activity, its relation to experimentation to knowledge change, and to professional scientists work. Analytic themes were developed to characterize students’¡Ç responses to interview questions and VNOS items. There are both differences and similarities between students’¡Ç responses in both contexts. Students seemed to recognize their activity as like what scientists would do, and understood it as a modeling task. Yet, students seemed to have few resources to draw upon to consider the nature of experimentation in either their own school work or in professional scientific work...publicStudent Beliefs about Professional and School Sciencearticlelocaloai:escholarship.org:ark:/13030/qt462087t82011-07-03T14:08:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/462087t8Aman KansalauthorDunny PotterauthorMani Srivastavaauthor2003-01-01Energy is a major constraint in the design of embedded sensor networks. The energy supplied by batteries with acceptable form factor may not be sufficient for several applications. Extracting energy from the environment is a feasible alternative in many practical scenarios. We present methods to make the most of the available energy in a distributed system and to operate reliably from highly variable energy sources. We also demonstrate the first version of our hardware which is compatible with several existing sensor nodes for enabling energy harvesting.publicEnvironmental Energy Management in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt9zp954hw2011-07-03T13:24:23Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9zp954hwHuiyu LuoauthorGreg Pottieauthor2005-01-01publicCorrelated Data Routing in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt3f74t94h2011-07-03T13:24:12Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3f74t94hDongjin SonauthorBhaskar KrishnamachariauthorJohn Heidemannauthor2004-01-01We experimentally investigate the impact of variable transmission power on link quality, and propose variable power link quality control techniques to enhance the performance of data delivery in wireless sensor networks. This study extends the state of the art in two key respects: first, while there are a number of previous results on power control techniques for wireless ad hoc and sensor networks, to our knowledge nearly all of them have been simulation or analytical studies that assume idealized link conditions; second, while there are several recent experimental studies that have shown the prevalence of non-ideal unreliable communication links in sensor networks, these have not thoroughly investigated the impact of variable transmission power.publicExperimental Study of the Effects of Tx Power Control and Blacklisting in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt0s11v2sx2011-07-03T13:23:42Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0s11v2sxJ. ElsonauthorD. Estrinauthor2004-01-01publicWireless Sensor Networks: A bridge to the Physical Worldarticlelocaloai:escholarship.org:ark:/13030/qt9ph492p22011-07-03T13:22:28Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9ph492p2Singh, AmarjeetauthorBudzik, DianeauthorChen, WillieauthorBatalin, MaximauthorKaiser, W Jauthor2007-01-15Many environmental applications require high temporal frequency (rapidly changing) and spatially distributed phenomena to be sampled with high fidelity. This requires mobile sensing elements to perform guided sampling in regions of high variability. We propose a multiscale approach for efficiently sampling such phenomena. This approach introduces a hierarchy of sensors according to the sampling fidelity, spatial coverage, and mobility characteristics. In this paper, we report the development of a two-tier multiscale system where information from a low-fidelity, high spatial (global) sensor actuates a mobile robotic node, carrying a high-fidelity, low spatial coverage (spot measurement) sensor, to perform guided sampling in the regions of high phenomenon variability. As a case study of the proposed multiscale paradigm, we investigated the spatiotemporal distribution of the light intensity in a forest understory. The performance of the multiscale approach is verified in simulation and on a physical system. Results suggest that our approach is adequate for the problem of high-frequency spatiotemporal phenomena sampling and significantly outperforms traditional sampling approaches such as a raster scan.publicMultiscaled Actuated Sensingmobile robotssensorsactuated sensinghigh frequency dynamic phenomenamobile robotic nodemobility characteristicsmultiscale paradigmmultiscale sensingsampling fidelityspatial coveragespatiotemporal distributiontwo-tier multiscale systemMultiscale Sensing: A New Paradigm for Actuated Sensing of High Frequency Dynamic Phenomenaarticlelocaloai:escholarship.org:ark:/13030/qt4r48w3bb2011-07-03T11:05:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4r48w3bbSingh, AmarjeetauthorKrause, Andreas R.authorGuestrin, CarlosauthorKaiser, W JauthorBatalin, Maximauthor2006-12-24In many sensing applications, including environmental monitoring, measurement systems must cover a large space with only limited sensing resources. One approach to achieve required sensing coverage is to use robots to convey sensors within this space.Planning the motion of these robots – coordinating their paths in order to maximize the amount of information collected while placing bounds on their resources (e.g., path length or energy capacity) – is a NP-hard problem. In this paper, we present an efficient path planning algorithm that coordinates multiple robots, each having a resource constraint, to maximize the “informativeness” of their visited locations. In particular, we use a Gaussian Process to model the underlying phenomenon, and use the mutual information between the visited locations and remainder of the space to characterize the amount of information collected. We provide strong theoretical approximation guarantees for our algorithm by exploiting the submodularity property of mutual information. In addition, we improve the efficiency of our approach by extending the algorithm using branch and bound and a region-based decomposition of the space. We provide an extensive empirical analysis of our algorithm, comparing with existing heuristics on datasets from several real world sensing applications.publicMultiscaled Actuated SensingEfficient Planning of Informative Paths for Multiple Robotsarticlelocaloai:escholarship.org:ark:/13030/qt6qt7q51z2011-07-03T11:02:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6qt7q51zHanbiao WangauthorKung YaoauthorDeborah Estrinauthor2005-01-01In this paper, we describes the informationtheoretic approaches to sensor selection and sensor placement in sensor networks for target localization and tracking.publicInformation-Theoretic Approaches for Sensor Selection and Placement in Sensor Networks for Target Localization and Trackingarticlelocaloai:escholarship.org:ark:/13030/qt9472q3qd2011-07-03T11:00:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9472q3qdDustin McIntireauthorKei HoauthorBernie YipauthorAmarjeet SinghauthorWinston WuauthorWilliam J. Kaiserauthor2006-01-01A broad range of embedded networked sensor (ENS) systems for critical environmental monitoring applications now require complex, high peak power dissipating sensor devices, as well as on-demand high performance computing and high bandwidth communication. Embedded computing demands for these new platforms include support for computationally intensive image and signal processing as well as optimization and statistical computing. To meet these new requirements while maintaining critical support for low energy operation, a new multiprocessor node hardware and software architecture, Low Power Energy Aware Processing (LEAP), has been developed. The LEAP architecture integrates fine-grained energy dissipation monitoring and sophisticated power control scheduling for all subsystems including sensor subsystems.publicThe Low Power Energy Aware Processing (LEAP) Embedded Networked Sensor System (MAS 12)articlelocaloai:escholarship.org:ark:/13030/qt87n3f38z2011-07-03T11:00:21Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/87n3f38zMadhavan VajapeyamauthorSatish VedantamauthorUrbashi Mitraauthor2006-01-01In resource limited, large scale underwater sensor networks, cooperative communication over multiple hops offers opportunities to save power. Intermediate nodes between source and destination act as cooperative relays. Herein, protocols coupled with space-time block code (STBC) strategies are proposed and analyzed for distributed cooperative communication. Amplify-and-forward type protocols are considered, in which intermediate relays do not attempt to decode the information. The Alamouti-based cooperative scheme proposed by Hua et al (2003) for flat-fading channels is generalized in order work in the presence of multipath, thus addressing a main characteristic of underwater acoustic channels. A time-reversal distributed space-time block code (TR-DSTBC) is proposed, which extends the dual-antenna TR-STBC (time reversal space-time block code) approach from Lindskog and Paulraj (2000) to a cooperative communication scenario for signaling in multipath. It is first shown that, just as in the dual-antenna STBC case, TR along with the orthogonality of the DSTBC essentially allows for decoupling of the vector ISI detection problem into separate scalar problems, and thus yields strong performance (compared with single hop communication) and with substantially reduced complexity over non-orthogonal schemes.publicCooperative Schemes for Underwater Acoustic Communications (AQU 3)articlelocaloai:escholarship.org:ark:/13030/qt7p59022p2011-07-03T11:00:13Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7p59022pH. LuoauthorX. KongauthorG. Pottieauthor2005-01-01The introduction of mobile sensors such as NIMS has generated a variety of new research topics. Here, we demonstrate our ongoing work of iteratively sampling and reconstructing a two-dimensional field using mobile sensors. The sampling is conducted in multiple iterations. Each time, the field statistical model and current reconstructed field are utilized to select most desirable sampling points from a pool of sampling candidates.publicSIP3: Iterative Sampling of the Sunlight Fieldarticlelocaloai:escholarship.org:ark:/13030/qt05x915kz2011-07-03T11:00:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/05x915kzRahul BalaniauthorIlias TsigkogiannisauthorSimon HanauthorRam Kumar RengaswamyauthorMani Srivastavaauthor2005-01-01In-situ reconfiguration is indispensable in sensor network deployments. It is required for efficient management and upgrade of software in large scale sensor networks, re-tasking a deployed network or for recovering a deployed system from crippling bugs or malicious intent. A spectrum of techniques for re-programming have been proposed. The major approaches are: 1. Full binary upgrade supported by TinyOS/Deluge mechansim that allows arbitrary changes to the functionality but incurs a high transmission and storage cost. 2. SOS operating system for sensor nodes consists of a static kernel that is extensible through modular extensions that can be installed and updated over the air. 3. Application specific virtual machines (ASVMs) are domain specific interpreters built on top of TinyOS to enable limited high-level changes to the functionality by injecting concise application level scripts. The three approaches vary in the cost and the flexibility of the updates that they can support. The nature of the update determines the most suitable technique. We have built a system that supports this complete hierarchy of reconfiguration.publicHierarchy of Reconfiguration in Sensor Network Software Systemsarticlelocaloai:escholarship.org:ark:/13030/qt02h4x5wp2011-07-03T09:47:41Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/02h4x5wpThanos StathopoulosauthorLewis GirodauthorJohn HeidemannauthorDeborah Estrinauthor2004-01-01Tiered systems comprised of low-power, resource constrained sensor devices (motes) and higher powered microservers are quickly becoming a reality. A typical deployment scenario would consist of several microserver-class devices, each of which would be responsible for a set of motes. Mote clustering is a set of tools and services that enables interoperation between motes and microservers, thereby allowing applications to seamlessly use the available hardware infrastructure in order to achieve their task. In particular, the goal is to leverage the computational power of the microservers, as well as the higher quality state view (in terms of both temporal and spatial resolution). One of the driving applications behind mote clustering is flexible triggering of imagers. This will be comprised of a collection of microservers with cameras attached to them, as well as a deployment of motes. The motes would sense the environment and trigger the cameras when something of interest is detected. Using mote herding, the application can associate mote locations and camera fields of view as well as locate the appropriate camera for each task.publicSystem Supoort for Coordinated Imaging for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt9jz9s82r2011-07-03T07:06:33Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9jz9s82rG.M. KobeleauthorJ. RiggleauthorR. BrooksauthorD. FriedlanderauthorC. TaylorauthorE. Stablerauthor2004-01-01publicInduction of Prototypes in a Robotic Setting Using Local Search MDLarticlelocaloai:escholarship.org:ark:/13030/qt0k03m88d2011-07-03T07:04:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0k03m88dRichard KarpauthorJeremy ElsonauthorDeborah EstrinauthorScott Shenkerauthor2003-01-01A model of optimally precise and globally consistent clock synchronization, using the model provided by Reference-Broadcast Synchronization.publicOptimal and Global Time Synchronization in Sensornetsarticlelocaloai:escholarship.org:ark:/13030/qt6tt8g4462011-07-03T07:04:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6tt8g446Juyoul KimauthorYeonjeong ParkauthorThomas C. Harmonauthor2003-01-01This work describes the integration of data acquisition hardware and software for the purpose acquiring not only data, but real-time transport model parameter estimates in the context of subsurface flow and transport problems. Integrated data acquisitionparameter estimation systems can be used to reduce data storage requirements, trigger event recognition and/or more detailed sampling actions, and otherwise enhance remote monitoring capabilities. The contaminant transport problem is posed here as the analogous heat transfer problem in a three-dimensional, intermediate-scale physical aquifer model. A constant source of warm water is fed into a sandy aquifer undergoing steady, unidirectional flow. The spatial distribution of temperature in the medium is monitored over time using 17 thermocouples embedded in the medium. These sensors log temperatures via conventional analog-to-digital conversion hardware driven by commercially available data acquisition software (LabVIEW™). Parameter estimation routines programmed in MATLAB™-based M-files are embedded in the LabVIEW data acquisition routine and access parameter estimation libraries, such as the descent method employed here, via the Internet. The integrated data acquisition-parameter estimation system is demonstrated for the estimation of (1) the thermal dispersion coefficients (analogous to mass dispersion coefficients), given a known heat source, and (2) the location of a heat source, given known thermal dispersion coefficients. In both cases, the parameter estimation procedure is executed repeatedly as the data are acquired. For the case of source location, the effect of the number of sensors on the parameter estimation procedure is also demonstrated. Reasonable parameter estimates are provided rapidly during both the transient and steady state phases of the experiments, with accuracy increasing with time and with the number of observations employed.publicReal-time Model Parameter Estimation for Analyzing Transport in Porous Mediaarticlelocaloai:escholarship.org:ark:/13030/qt9c1796x62011-07-03T07:04:36Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9c1796x6Aman KansalauthorArun SomasundaraauthorDavid JeaauthorMani SrivastavaauthorDeborah Estrinauthor2004-01-01We develop a fluid infrastructure for embedded networking through the introduction of actuated elements in the network infrastructure. Our design allows the network to adapt to run time dynamics in order to maintain required levels of performance. Our approach yields significant advantages for energy constrained systems, sparsely deployed networks, delay tolerant networks, and in security sensitive situations.publicIntelligent Fluid Infrastructure for Embedded Networksarticlelocaloai:escholarship.org:ark:/13030/qt2zs0d08c2011-07-03T07:04:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2zs0d08cAman KansalauthorEric YuenauthorWilliam J KaiserauthorGregory J PottieauthorMani Srivastavaauthor2004-01-01Realistic sensing environments pose a significant challenge to ensuring the quality of sensing due to the unpredictable nature and dynamics of sensing media. This paper presents a practical approach for reducing sensing uncertainty by exploiting mobility while at the same time elimitaing the mobility overheads of complex navigation and energy expense.publicSensing Uncertainty Reduction Using Low Complexity Actuationarticlelocaloai:escholarship.org:ark:/13030/qt4qc1q1jc2011-07-03T07:00:28Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4qc1q1jcMohammad RahimiauthorMark HansenauthorWilliam KaiserauthorGaurav SukhatmeauthorDeborah Estrinauthor2004-01-01publicAdaptive Sampling in Environmental Roboticsarticlelocaloai:escholarship.org:ark:/13030/qt1nx4w72g2011-07-03T06:19:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1nx4w72gE. AgapieauthorG. ChenauthorD. HoustonauthorE. HowardauthorJ. KimauthorM. Y. MunauthorA. MondscheinauthorS. ReddyauthorR. RosarioauthorJ. RyderauthorA. SteinerauthorJ. BurkeauthorE. EstrinauthorM. HansenauthorM. Rahimiauthor2007-01-01publicUrban SensingSeeing Our Signals: Combining location traces and web-based models for personal discoveryarticlelocaloai:escholarship.org:ark:/13030/qt9s44v89q2011-07-03T06:14:03Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9s44v89qTatyana A. BendikovauthorThomas C. Harmonauthor2003-01-01publicA Sensitive and Highly Selective Nitrate Ion Selective Electrode from a Pencil Lead: An Analytical Laboratory Experimentarticlelocaloai:escholarship.org:ark:/13030/qt4mt9x7qk2011-07-03T06:13:57Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4mt9x7qkRamanathan, Nithyaauthor2008-10-01This paper presents Confidence, a tool for identifying and addressing faults in wireless sensing systems. Confidence pinpoints potential sensor and network faults in real time, allowing users to validate unexpected data and address any failures in the field. By introducing a well defined, low-dimension feature space, and functions to map sensor data into this space, we are able to achieve fault detection and diagnosis with relatively simple mechanisms such as outlier detection. Users can directly modify system outcomes by altering a classification label in instances when Confidence's automated algorithm draws the wrong inference. This label is applied to all similar points in the feature space, enabling Confidence to learn from user interaction in the field. This abstraction for incorporating user knowledge provides a lightweight and easy- to-understand interface for the user, while limiting user bur- den and reducing the required a priori environmental knowledge. Confidence has performed well on real-world deployments, including one deployment of 130 sensors, replayed datasets, and network simulations. Confidence accurately detects and diagnoses at least 90% of all data, and user interaction improves it's performance.publicSystemsfault detectionfault diagnosishuman in the loopFixing Faults in Wireless Sensing Systems with Confidencearticlelocaloai:escholarship.org:ark:/13030/qt5qm2r7px2011-07-03T06:13:43Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5qm2r7pxZhao, YueauthorPottie, Gregory Jauthor2008-11-21In this paper, we investigate the optimal spectrum management problem in multiuser frequency selective interference channels. First, a simple pairwise condition for FDMA to be optimal is discovered: for any two among all the users, as long as the normalized cross couplings between them two are both larger than or equal to 1/2, orthogonalization between these two users is optimal for every existing user. Therefore, this single condition applies to achieving all Pareto optimal points of the rate region. Furthermore, not only is this condition sufficient, but in symmetric channels, it is also necessary for FDMA to be always optimal. When the normalized cross couplings are less than 1/2, the optimal spectrum management strategy can be a mixture of frequency sharing and FDMA, depending on users’ power constraints. We first explicitly solve the sum-rate maximization problem in two user symmetric flat channels by solving a closed form equation, providing the optimal spectrum management with a clear intuition as the optimal combination of flat FDMA and flat frequency sharing. Next, we show that this result leads to a primal domain convex optimization formulation for generalizations to frequency selective channels. Finally, we show that all the general optimization problems with n>=2 users and an arbitrary weighted sum-rate objective function in non-symmetric frequency selective channels can be solved by primal domain convex optimization with the same methodology.publicSystemsOptimal spectrum managementFDMA optimality conditionorthogonalization vs. sharingprimal domain convex optimizationinterference channelOptimal Spectrum Management in Multiuser Interference Channelsarticlelocaloai:escholarship.org:ark:/13030/qt47k5b67p2011-07-03T06:13:37Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/47k5b67pStathopoulos, ThanosauthorMcIntire, DustinauthorKaiser, W Jauthor2007-11-15This paper describes a new embedded networked sensor platform architecture that combines hardware and software tools providing detailed, fine-grained real-time energy usage information. We introduce the LEAP2 platform, a qualitative step forward over the previously developed LEAP and other similar platforms. LEAP2 is based on a new low power ASIC system and generally applicable supporting architecture that provides unprecedented capabilities for directly observing energy usage of multiple subsystems in real-time. Real-time observation with microsecond-scale time resolution now enables direct accounting of energy dissipation for each computing task as well as for each hardware subsystem. This new hardware architecture is exploited with our new software tools, etop and endoscope. A series of experimental investigations provide high-resolution power information in networking, storage, memory and processing for primary embedded networked sensing applications. Using these results obtained in real-time we show that for a large class of wireless sensor network nodes, there exist several interdependencies in energy consumption between different subsystems. Through the use of our measurement tools we demonstrate that by carefully selecting the system operating points, energy savings of over 60% can be achieved while retaining system performance.publicSystemsEndoscopeLEAP2EMAP2Energy-awareThe Energy Endoscope: Real-time Detailed Energy Accounting for Wireless Sensor Nodesarticlelocaloai:escholarship.org:ark:/13030/qt4zw2f3s62011-07-03T06:13:32Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4zw2f3s6V.BychkovskiyauthorS.MegerianauthorD.EstrinauthorM.Potkonjakauthor2003-01-01Numerous factors contribute to errors in sensor measure- ments. In order to be useful, any sensor device must be calibrated to adjust its accuracy against the expected measurement scale. In large- scale sensor networks, calibration will be an exceptionally dicult task since sensor nodes are often not easily accessible and manual device-by- device calibration is intractable. In this paper, we present a two-phase post-deployment calibration technique for large-scale, dense sensor de- ployments. In its �rst phase, the algorithm derives relative calibration relationships between pairs of co-located sensors, while in the second phase, it maximizes the consistency of the pair-wise calibration func- tions among groups of sensor nodes. The key idea in the �rst phase is to use temporal correlation of signals received at neighboring sensors when the signals are highly correlated (i.e. sensors are observing the same phenomenon) to derive the function relating their bias in amplitude. We formulate the second phase as an optimization problem and present an algorithm suitable for localized implementation. We evaluate the perfor- mance of the �rst phase of the algorithm using empirical and simulated data.publicColibration: A Collaborative Approach to In-Place Sensor Calibrationarticlelocaloai:escholarship.org:ark:/13030/qt2446x3n42011-07-03T06:13:23Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2446x3n4Bulusu NauthorHeidemann JauthorEstrin D.authorTran T.author2003-01-01Embedded networked sensors promise to revolutionize the way we interact with our physical envi- ronment and require scalable, ad hoc deployable and energy-ecient node localization/positioning. This paper describes the motivation, design, implementation and experimental evaluation (on sharply resource-constrained devices) of a self-con�guring localization system using radio beacons. We identify beacon density as an important parameter in determining localization quality, which saturates at a transition density. We develop algorithms to improve localization quality by (i) automating placement of new beacons at low densities (HEAP) and (ii) rotating functionality among redundant beacons while increasing system lifetime at high densities (STROBE).publicSelf-configuring Localization Systems: Design and Experimental Evaluationarticlelocaloai:escholarship.org:ark:/13030/qt5h22d6xv2011-07-03T06:13:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5h22d6xvJ. ElsonauthorS. BienauthorN. BusekauthorV. BychkovskiyauthorA. CerpaauthorD. GanesanauthorL. GirodauthorB. GreensteinauthorT. SchoellhammerauthorT. StathopoulosauthorD. Estrinauthor2003-01-01An overview of EmStar, CENS'' Linux-based framework for developing sensor network software.publicEmStar: An Environment for Developing Wireless Embedded Systems Softwarearticlelocaloai:escholarship.org:ark:/13030/qt01h8v8qt2011-07-03T06:13:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/01h8v8qtDeepak GanesanauthorSylvia RatnasamyauthorHanbiao WangauthorDeborah Estrinauthor2003-01-01Wireless sensor networks have attracted attention from a diverse set of researchers, due to the unique combination of distributed, resource and data processing constraints. However, until now, the lack of real sensor network deployments have resulted in ad-hoc assumptions on a wide range of issues including topology characteristics and data distribution. As deployments of sensor networks become more widespread [1, 2], many of these assumptions need to be revisited. This paper deals with the fundamental issue of spatio-temporal irregularity in sensor networks We make the case for the existence of such irregular spatio-temporal sampling, and show that it impacts many performance issues in sensor networks. For instance, data aggregation schemes provide inaccurate results, compression efficiency is dramatically reduced, data storage skews storage load among nodes and incurs significantly greater routing overhead. To mitigate the impact of irregularity, we outline a spectrum of solutions. For data aggregation and compression, we propose the use of spatial interpolation of data (first suggested by Ganeriwal et al in [3]) and temporal signal segmentation followed by alignment. To reduce the cost of data-centric storage and routing, we propose the use of virtualization, and boundary detection.publicCoping with irregular spatio-temporal sampling in sensor networksarticlelocaloai:escholarship.org:ark:/13030/qt59k7w3tv2011-07-03T06:12:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/59k7w3tvHuiyu LuoauthorAmeesh PandyaauthorGregory Pottieauthor2003-01-01This paper discusses the sensing, quantization, and interpolation errors in distributed sensor networks.publicDetection Fidelity in Distributed Wireless Sensor Neworksarticlelocaloai:escholarship.org:ark:/13030/qt2g49z78g2011-07-03T06:12:48Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2g49z78gAlberto CerpaauthorNaim BusekauthorDeborah Estrinauthor2003-01-01This paper describes SCALE, a software tool to make radio connectivity measurements and presents results of using SCALE with Mica 1 and 2 in three different environments under systematically varied conditions.publicSCALE: A tool for Simple Connectivity Assessment in Lossy Environmentsarticlelocaloai:escholarship.org:ark:/13030/qt97x201c32011-07-03T06:12:43Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/97x201c3Ram KumarauthorVlasios TsiatsisauthorMani B Srivastavaauthor2003-01-01Explored the latency and energy tradeoffs introduced by the heterogeneity of sensor nodes in the netework.publicComputation Hierarchy for In-network processingarticlelocaloai:escholarship.org:ark:/13030/qt9s9717fw2011-07-03T06:12:37Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9s9717fwLewis GirodauthorJeremy ElsonauthorAlberto CerpaauthorThanos StathopoulosauthorNithya RamanathanauthorDeborah Estrinauthor2003-01-01Em* (pronounced EmStar) is a software environment for developing and deploying Wireless Sensor Network (WSN) applications on Linux-class hardware platforms (called ''Microservers''). Em* consists of libraries that implement message-passing IPC primitives, tools that support simulation, emulation, and visualization of live systems, both real and simulated, and services that support for networking, sensing, and time synchronization. While Em*''s design has favored ease of use and modularity over efficiency, the resulting increase in overhead has not been an impediment to any of our current projects.publicEmStar: a Software Environment for Developing and Deploying Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt1w5241rv2011-07-03T06:11:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1w5241rvShadnaz AsgariauthorRalph E. HudsonauthorKung Yaoauthor2006-01-01Estimation of three-dimensional (3-D) direction-of-arrival angles (DOA) has received a significant amount of attention over the last several decades. It has also played an important role in array signal processing areas such as radar, sonar, radio astronomy, and mobile communication systems. In this work, we extend our original approximate maximum likelihood (AML) algorithm which has already been provened to work very well under a two-dimensional scenario, to work for a three-dimensional case. The main challenge in this extension is to have good accuracy of DOA estimation for all possible azimuth and elevation angles, while keeping the complexity of algorithm still as low as possible. We will show that for some specific subarray configurations named as isotropic arrays, we can achieve this goal very well.publicOptimized three-dimensional acoustical array for source localization (SYS 15)articlelocaloai:escholarship.org:ark:/13030/qt43c704nh2011-07-03T06:11:47Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/43c704nhJennifer L. WongauthorTom SchoellhammerauthorMiodrag PotkonjakauthorDeborah Estrinauthor2006-01-01Efficient deployment of a distributed wireless systems is a fundamental and difficult task. When considering the problem from the perspective of a sensing system, the challenge of efficient deployment becomes two-fold. First, the main purpose of the deployment is the gathering and quality of the spatial phenomena collected from the environment. Secondly, the selected positions should communicate efficiently.Due to the presence of unknowns in the deployment environment and lossy communication links, prediction of efficient deployment positions for communication is difficult. We propose the use of deployed sensor nodes for analysis of the communication qualities in the deployment environment. Using a small collected set of communication quality measurements, we propose an optimization approach for determining the deployment positions of additional nodes into the network in order to improve the communication quality and therefore the lifetime of the network. In order to solve the optimization problem, we map the communication qualities into an equivalent corresponding instance of non-linear programming in a new communication and lifetime space. We analyze the new deployment approach using both actually deployed networks, as well as extensive simulation studies.publicStrategic Deployment in the Presence of Lossy Communication Links (SYS 21)articlelocaloai:escholarship.org:ark:/13030/qt20t3n8r82011-07-03T06:11:43Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/20t3n8r8Nathan Yauauthor2006-01-01publicSensorBase.org: A Centralized Repository to Slog Sensor Network Data (KNO 2)articlelocaloai:escholarship.org:ark:/13030/qt4z7076sm2011-07-03T06:11:38Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4z7076smYu-Ching TongauthorGreg Pottieauthor2006-01-01In a sensor network environment, where energy and communication resources are limited but the sensors are abundant, it is beneficial if the network only activates sufficient, with little excess, sensors to achieve a given task.In this paper we propose a utility function for a localization application that provides a means of sensor selection, based on a source-sensor spatial relationship.publicUtility Function for the Sensor Selection Problem in Localization Applications (SYS 22)articlelocaloai:escholarship.org:ark:/13030/qt48h986b42011-07-03T06:11:33Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/48h986b4Ben GreensteinauthorEddie KohlerauthorDeborah Estrinauthor2005-01-01publicSensor Network Application Construction Kit (SNACK)articlelocaloai:escholarship.org:ark:/13030/qt21c8q5cw2011-07-03T06:11:28Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/21c8q5cwBeth StaufferauthorMrinal MahapatroauthorChongwu ZhouauthorAri RequichaauthorAlex LeeauthorChao LiauthorStefanie MoorthiauthorDave Caronauthor2005-01-01With an increase in blooms of harmful algae on both national and global levels, it is becoming ever more important to be able to detect these organisms at high spatial and temporal resolutions. It is also imperative that methods of detection are able to identify target cells at low concentrations. To this end we present a number of immunologically-based techniques for detecting cells of Aureococcus anophagefferens, the cause of ’�¡�ÈBrown Tides’�¡�É off the Mid-Atlantic coast. These techniques include flow cytometry, atomic force microscopy, and nanowire- and nanotube-based sensing. We also detail experiments carried out in a laboratory testbed demonstrating ecologically significant behavior patterns in two harmful algal species responsible for ’�¡�ÆBrown’�¡�Ç and ’�¡�ÆRed’�¡�Ç tides on the east and west coast, respectively.publicAQU2: Detection and Identification of Aquatic Microorganismsarticlelocaloai:escholarship.org:ark:/13030/qt9w31d5b52011-07-03T06:11:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9w31d5b5Beth StaufferauthorTechnical StaffauthorUSCauthor2003-01-01None provided.publicDetection Of Marine Microorganisms using Immuno-Based Methodsarticlelocaloai:escholarship.org:ark:/13030/qt4pv7r6n32011-07-03T06:11:14Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4pv7r6n3Bin ZhangauthorAmit DhariwalauthorEric ShiehauthorBeth StaufferauthorCarl ObergauthorDave CaronauthorAri RequichaauthorGaurav Sukhatmeauthor2005-01-01The goal of adaptive sampling is to acquire high-resolution data in the important regions with relative less sensor nodes. We built a system to study the behavior of algae. The system consists of both static sensor nodes and mobile sensor nodes. The sensors equipped include thermistors and fluorometers. Thermistors measure one of key environment parameters for the growth of the algae while the fluorescence of chlorophyll provides useful pro xy for algal abundance. The system has been deployed in Lake Fulmor in James Reserve and the data collected in field are presented.publicAQU1: Adaptive Sampling for Marine Microorganism Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt7r04j82d2011-07-03T06:11:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7r04j82dMichael HamiltonauthorEric GrahamauthorDeborah EstrinauthorPhil RundelauthorVanessa Rivera Del RioauthorRichard GuyauthorS ean Askayauthor2005-01-01EMISSARY is a new system under development for an advanced data visualization, spatio-temporal modeling interface, and field portable tools for in-situ data exploration of sensormicronets and distributed instrument management. Our research is defining a set of functional capabilities for an advanced system for in the field communication with a sensormicronet and distributed instrumentation, on-line and interactive modeling tools, and system diagnostics and configuration interfaces. Conceptually this system would be a hand-held PDA or laptop class computer with wireless communication to mote-class devices (sensor nodes), networked data-logging instruments, WAN/LAN, and the Internet.publicFrom Sensor to Scientist Emissary and Cyberinfrastructure for Sensor Networks in Terrestrial Ecological Researcharticlelocaloai:escholarship.org:ark:/13030/qt50c7f1532011-07-03T05:30:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/50c7f153Ning XuauthorRamesh Govindanauthor2003-01-01We will demonstrate the collection of accelerometer reading by motes in a multi-hop manner, we have implemented data compression to reduce dataset and a NACK based protocol to achieve reliability.publicA Wireless Seismic Sensing Arrayarticlelocaloai:escholarship.org:ark:/13030/qt7kb1r6142011-07-03T05:30:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7kb1r614Beth A. StaufferauthorDavid CaronauthorMrinal MahapatroauthorAri RequichaauthorUniversity of Southern CaliforniaauthorMarine BiologyauthorLaboratory for Molecular Roboticsauthor2004-01-01With an increase in blooms of harmful algae on both national and global levels, it is becoming ever more important to be able to detect these organisms at high spatial and temporal resolutions. It is also imperative that methods of detection are able to identify target cells at low concentrations. To this end we present a number of immunologically-based techniques for detecting cells of Aureococcus anophagefferens, the cause of ’¡ÈBrown Tides’¡É off the Mid-Atlantic coast. These techniques include flow cytometry, enzyme-linked immunosorbent assay (ELISA), quartz crystal microbalance (QCM), and atomic force microscopy (AFM).publicProgress in Detection and Identification of Marine Microorganismsarticlelocaloai:escholarship.org:ark:/13030/qt7td3g73w2011-07-03T05:29:41Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7td3g73wRatâko, AlexanderauthorDietrich, HeidiauthorPark, YeonjeongauthorGonzalez-Jimenez, RubyauthorKim, DohyunauthorAswin, BuddyauthorGoldberg, IraauthorHarmon, ThomasauthorJudy, Jackauthor2009-05-12Inorganic nitrogen (nitrate, NO3-) is a major source of pollution in groundwater, surface water and the air. Application of nitrate-containing fertilizers can create distributed or non-point source pollution problems. Scalable nitrate sensors (sensors which are small and inexpensive) would enable us to better assess non-point source pollution processes in agronomic soils, groundwater and rivers. Sensor research groups in the CENS have been working toward high-performance scalable nitrate sensors using (1) potentiometric, (2) amperometric method, and the recent addition is (3) spectrochemical sensor. 1. Potentiometric Nitrate Sensor. This work describes the fabrication and testing of inexpensive PVC-membrane-based ion selective electrodes (ISEs) for monitoring nitrate levels in soil water environments. Over the past year, we emphasized testing of the in situ behavior of fabricated sensors in soils subject to irrigation with dairy manure water. Observed temporal responses for the nitrate sensors exhibit diurnal cycling with elevated nitrate levels at night and depressed levels during the day; these cycles are prominent even after rigorous temperature corrections. We have thus far concluded that while modern ISEs are not yet ready for long-term, unattended deployment, short-term installations (on the order of 2 to 4 days) are viable and may provide semi-quantitative insights into nitrogen dynamics in complex soil systems. 2. Amperometric Nitrate Sensor. A simple and sensitive amperometric nitrate sensor is microfabricated on the silicon chip and uses a nitrate-sensitive silver electrode. The concentration is determined by double-potential-step chronocoulometry because of high SNR and rejection of oxygen background current. The limit of detection ranges from 4 to 75 µM, and the upper limit of the linear range varies between 500 and 2000 µM. HPO42-/PO34- , Ca2+, and Sr2+ show significant interference (> 20 % signal distortion). We proposed a compact sample-preparation system based on Donnan dialysis to minimize the interference. The novel dialyzer uses small-bore tubes in containing solutions and a peristaltic pump in circulating the solutions to promote agitation. By using an anion-exchange membrane (AEM), the dialyzer removes cations completely and reduces interfering anions significantly from groundwater samples. Major advantages of the novel dialyzer are (1) high dialysis efficiency (~ 90 %), (2) linear response, and (3) reasonable throughput (1 samples/hr).A numerical analysis based on the one-dimensional bi-ionic-system-in-series model provides a good prediction of dialyzer performance. 3. Spectrochemical Nitrate Sensor. A multiplexible, miniaturized, and spectrochemical sensor is proposed because optical methods usually provide superior long-term reliability. UV light is absorbed by nitrate while propagating through groundwater sample in a liquid-core capillary waveguide, and absorbance is analyzed to quantify nitrate using a fiber-optic spectrometer. Using fiber-optic cables and optical multiplexers, multiple sensors can be operated remotely by single spectrophotometer and light source. Multivariate analysis is used to compensate these interferences from ionic and neutral species and baseline from dissolved organic species in groundwater, and calculate nitrate concentration precisely. A series of numerical analyses were performed to assess effects of spectrometric noises and interferences. According to the analyses, a large sharp Gaussian noise with a peak located near the peak of nitrate spectra will generate a significant error. Using a bench-top spectrometer, nitrate spectra in wide concentration range (10-7 to 1-4 M) were recorded to obtain concentration. It is observed that spectra were linear over the range.publicSensorsMicro- and Mini-nitrate Sensors for Monitoring of Soils, Groundwater and Aquatic Systemsarticlelocaloai:escholarship.org:ark:/13030/qt96m2k5tx2011-07-03T05:29:21Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/96m2k5txG. DorettoauthorE. JonesauthorS. Soattoauthor2004-01-01publicSpatially homogeneous dynamic texturesarticlelocaloai:escholarship.org:ark:/13030/qt6xn7x7112011-07-03T05:29:12Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6xn7x711S. ManayauthorA. J. YezziauthorB. W. HongauthorS. Soattoauthor2004-01-01publicIntegral Invariant Signaturesarticlelocaloai:escholarship.org:ark:/13030/qt6r5652p82011-07-03T05:28:27Z am 3u Center for Embedded Network SensingVol. 3993 (Jan. 2006) 514-521eScholarship, University of Californiahttps://escholarship.org/uc/item/6r5652p8Golubchik, LeanaauthorCaron, David A.authorDas, AbhimanyuauthorDhariwal, AmitauthorGovindan, RameshauthorKempe, DavidauthorOberg, CarlauthorSharma, AbhishekauthorStauffer, BethauthorSukhatme, Gauravauthorzhang, binauthor2006-01-01Observing systems facilitate scientific studies by instrumenting the real world and collecting corresponding measurements, with the aim of detecting and tracking phenomena of interest. A wide range of critical environmental monitoring objectives in resource management, environmental protection, and public health all require distributed observing systems. The goal of such systems is to help scientists verify or falsify hypotheses with useful samples taken by the stationary and mobile units, as well as to analyze data autonomously to discover interesting trends or alarming conditions. In our project, we focus on a class of observing systems which are embedded into the environment, consist of stationary and mobile sensors, and react to collected observations by reconfiguring the system and adapting which observations are collected next. In this paper, we give an overview of our project in the context of a marine biology application.publicMultiscaled Actuated SensingA Generic Multi-Scale Modeling Framework for Reactive Observing Systems: An Overviewarticlelocaloai:escholarship.org:ark:/13030/qt9bb9q3xn2011-07-03T05:28:21Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9bb9q3xnArnaud BenahmedauthorNikolaus RechnerauthorRobert LamauthorMichael BendikovauthorAlexander Ratkoauthoryair WisjboomauthorChristopher ButlerauthorIra GoldbergauthorDohyun KimauthorMichael GlickmanauthorDiwei ZhangauthorMike LeuauthorSiyang ZhengauthorMrinal MahapatroauthorPamela GrossauthorBeth StaufferauthorAlex LeeauthorMark ThomsponauthorChongwu ZhouauthorDavid CaronauthorAri RequichaauthorThomas HarmonauthorJack JudyauthorYu-Chong TaiauthorChih-Ming Hoauthor2006-01-01publicSEN 0: Wireless Miniature Sensors for CENS Overviewarticlelocaloai:escholarship.org:ark:/13030/qt78x8d34p2011-07-03T05:28:17Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/78x8d34pStefanie MoorthiauthorBeth StaufferauthorCarl ObergauthorGaurav SukhatmeauthorDavid Caronauthor2006-01-01Lingulodinium polyedrum is a marine, bioluminescent dinoflagellate that is a common red tide species and potential toxin producer (yessotoxin) along a large expanse of the coast of Southern California. Little is known about the factors leading to bloom formation, or its impact on planktonic food webs. Bloom abundances can reach over 1000 cells/ml, events in which the interplay of physical forces (wind and surface currents) and of algal behavior (vertical migration) presumably play an important role. Using the CENS laboratory test bed, we have examined the pattern and timing of vertical migration by the dinoflagellate in a 2m water column on an 11h:13h light:dark photoperiod.publicAQU 2: Investigating Vertical Migration and Bloom Dynamics of a Red Tide Dinoflagellate: Laboratory Observations and a Novel Sensing Approacharticlelocaloai:escholarship.org:ark:/13030/qt939782v32011-07-03T05:28:12Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/939782v3Gaurav SukhatmeauthorDavid CaronauthorCarl ObergauthorBin ZhangauthorAmit DhariwalauthorBeth StaufferauthorStefanie MoorthiauthorArvind Pereiraauthor2006-01-01publicAQU 0: ENS Approaches for Observing and Sensing of Microbial Communities in Aquatic Ecosystems An Overviewarticlelocaloai:escholarship.org:ark:/13030/qt3r17022p2011-07-03T05:28:07Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3r17022pMichael P. HamiltonauthorPhil RundelauthorEric GrahamauthorMichael AllenauthorDeborah EstrinauthorMark HansenauthorMike TaggartauthorSean AskayauthorRichard GuyauthorKevin ChangauthorYeung LamauthorVanessa Rivera del RioauthorNathan YauauthorEric Yuenauthor2006-01-01publicTER 0: TEOS: Terrestrial Ecology Observing Systems Overview of Embedded Networked Systems and EMISSARY Tools for Instrument Management and Data Explorationarticlelocaloai:escholarship.org:ark:/13030/qt26f4730g2011-07-03T05:28:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/26f4730gLucas JohnsonauthorEric Grahamauthor2005-01-01The relative abundance of Coleoptera and Lepidoptera was compared to variation in temperature and relative humidity data from the Trailfinder Weather Station at James Reserve. A light trap was constructed and used in association with the NIMS 2 imager to record insect visitations. The trap consisted of a black light contained in a 19.5 ��× 19.5 ��× 10 inches covered with a white sheet. An additional light above the trap provided illumination for insect identification. A visitation event was defined as when an insect first became immobile on the illuminated area of the insect box. Images were captured every five minutes from 9PM to 5AM on July 30th through August 12th 2005. From independent, direct observation, the average residence time of Coleoptera and Lepidoptera is 34 minutes and 36 minutes respectively. This indicates that a photograph every five minutes provides sufficient resolution. The abundance of Coleoptera was strongly correlated with temperature and weakly with humidity. The abundance of Lepidoptera was weakly correlated with both temperature and humidity.publicRelative Abundance of Coleoptera and Lepidopteraarticlelocaloai:escholarship.org:ark:/13030/qt01w4350s2011-07-03T05:27:57Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/01w4350sKiran GuarajaauthorJohn HeidemannauthorYuan LiauthorIsmael SevickauthorAffan SyedauthorJack WillsauthorWei Yeauthor2005-01-01This project investigates the development of undersea sensor networks. We highlight potential applications to off-shore oilfields for seismic monitoring, equipment monitoring, and underwater robotics. We identify research directions in short-range acoustic communications, MAC, time synchronization, and localization protocols for high-latency acoustic networks, long-duration network sleeping, and application-level data scheduling. We describe our preliminary design on short-range acoustic communication hardware, and summarize results of high-latency time synchronization.publicSNUSE Sensor Networks for Undersea Seismic Experimentationarticlelocaloai:escholarship.org:ark:/13030/qt75s529v42011-07-03T05:27:51Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/75s529v4Keith MayoralauthorBen TitzerauthorJens Palsbergauthor2005-01-012005 CENS Undergraduate InternAvrora, a set of simulation and analysis tools created by the UCLA compilers group, is designed to allow for the debugging of programs meant to run on sensor-networks, as well as provide tools to aid in the analysis of how those programs affect the sensor nodes both individually as well as in a sensor network. The goal of the summer is to implement support for other platform types and thus increase Avrora’�¡�Çs ability to simulate other types of sensor networks. This objective requires research of different platforms which may share similar devices to those of the already implemented MicaZ and Tmote Sky. In the future, this can lead to the ability to simulate different varieties of sensor netowkrs including heterogeneous networks.publicImplementing MicaZ Support for the AVRora Simulatorarticlelocaloai:escholarship.org:ark:/13030/qt275130p22011-07-03T05:27:47Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/275130p2Jessica FengauthorMiodrag Potkonjakauthor2003-01-01Location discovery is a task of fundamental importance in wireless ad-hoc networks. The standard localization problem is difficult due to presence of errors in distance measurements and also the need to minimize communication cost. In addition, in real-life situations, there is also a need to consider the existence of obstacles when solving localization problem and interpreting measurements. Obstacles are defined as objects in the instrumented field that significantly alter (prolong) distance measurements. This problem has not yet been properly addressed so far due to its computational intractability and difficulty. Our goal is to introduce conceptual approaches, develop algorithms and software, and also validation techniques to identify and localize obstacles during simultaneous location discovery. The starting point is formulating location discovery as a nonlinear function minimization problem...publicObstacle Identification and Localizationarticlelocaloai:escholarship.org:ark:/13030/qt51n0073n2011-07-03T05:19:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/51n0073nK. ChintalapudiauthorA. DhariwalauthorR. GovindanauthorG.S. Sukhatmeauthor2004-01-01publicAd-Hoc Localization Using Ranging and Sectoringarticlelocaloai:escholarship.org:ark:/13030/qt5t57f9d42011-07-03T05:19:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5t57f9d4V. BokserauthorC. ObergauthorG. SukhatmeauthorA. Requichaauthor2004-01-01publicA Small Submarine Robot for Experiments in Underwater Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt8jj1w97b2011-07-03T05:18:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8jj1w97bBendikov, TatyanaauthorKim, JuyoulauthorHarmon, T Cauthor2005-05-05This work describes the development and testing of a sensitive and selective potentiometric nitrate microsensor based on doped polypyrrole films. Utilizing 6–7 µm carbon fibers as a substrate for pyrrole electropolymerization allowed fabrication of flexible, miniature and inexpensive sensors for in situ monitoring of nitrate. The sensors have a rapid response (several seconds) and in their characteristics are competitive with expensive commercial nitrate ion selective electrodes (ISE), exhibiting Nernstian behavior (slopes 54 ± 1 mV per log cycle of nitrate concentration (n=8), at T=22°C), a linear response to nitrate concentrations spanning three orders of magnitude (0.1–10⁻⁴ M or 6200–6.2 ppm of NO₃⁻), and a detection limit of (3 ± 1) × 10⁻⁵ M (1.25–2.5 ppm). After a 2-month-period, the response was unchanged, and after 4.5 months, one version of the electrode continued to exhibit significant sensitivity to nitrate. Several polypyrrole nitrate microsensors were embedded sequentially downstream from a point source of nitrate solution in an intermediate scale physical groundwater model as a test of their performance under simulated environmental conditions. The microsensors responded appropriately to the approaching nitrate solution front, demonstrating dispersion and attenuation of the nitrate concentrations that increased with distance from the source.publicNitrate microsensorPotentiometryPolypyrroleCarbon fibersNitrate transportDevelopment and Environmental Application of a Nitrate Selective Microsensor Based on Doped Polypyrrole Filmsarticlelocaloai:escholarship.org:ark:/13030/qt2tp2w3g02011-07-03T05:17:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2tp2w3g0Jeremy Elsonauthor2003-01-01Ph.D. Dissertation, University of California, Los Angeles, 2003publicTime Synchronization in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt1s15s57s2011-07-03T05:17:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1s15s57sWilliam J. KaiserauthorGregory J. PottieauthorMani SrivastavaauthorGaurav S. SukhatmeauthorJohn VillasenorauthorDeborah Estrinauthor2003-01-01This Technical Report introduces Networked Infomechanical Systems (NIMS) technology and the general principles of self-aware, physically reconfigurable sensor networks.publicNetworked Infomechanical Systems (NIMS) for Ambient Intelligencearticlelocaloai:escholarship.org:ark:/13030/qt76k0k3rv2011-07-03T05:15:34Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/76k0k3rvChristine BorgmanauthorMelissa CookauthorDeborah FieldsauthorKathy GriffisauthorAletha HarvenauthorKaren KimauthorKelli MillwoodauthorWilliam SandovalauthorVandana ThadaniauthorJillian WallisauthorJoe Wiseauthor2006-01-01This poster highlights the progress of CENS Pre-College Education group, including the Education AV tool development and the CENSEI project. In particular, the Education AV group, as part of the Emissary research team, is developing educational tools utilizing acoustic and image sensing and has developed the first iDCT, interactive Data Classification Tool, focusing on bird nest boxes. The CENSEI project, (CENS Education cyberInfrastructure) is creating a web-based portal for CENS inquiry curricular units for middle school and high school as well as conducting research on related science inquiry and data management issues.publicEDU 3: Pre-College Activities: CENSEI and Education Tools related to Audio/Visual Sensingarticlelocaloai:escholarship.org:ark:/13030/qt34c134f22011-07-03T05:15:24Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/34c134f2Per Henrik BorgstromauthorVictor ChenauthorBrett JordanauthorMichael J. StealeyauthorJon BinneyauthorAkhilesh SinghaniaauthorYeung LamauthorEric YuenauthorMaxim A. BatalinauthorWilliam J. Kaiserauthor2006-01-01Environmental monitoring has proven to be a rich source of biological and ecological data but typically does not conform to traditional monitoring techniques. Events of interest are often dynamic and may not tolerate the introduction of a conventional infrastructure without disrupting the environment being monitored. The new NIMS architectures require minimal infrastructure, are rapidly deployable, and have self anchoring coordinate systems. Simple cableways provide system mobility with minimal occlusion of the monitored transect allowing for accurate positioning and high positional resolution within the space of interest. These new systems have been developed to operate in either a two dimensional plane (NIMS-RD: e.g. monitor river or stream properties) or in a three dimensional volume (NIMS-3D: e.g. monitor incident solar radiation under a forest canopy).publicMAS 4: Networked InfoMechanical Systems (NIMS): New Architectures and Systems for Actuated Observationarticlelocaloai:escholarship.org:ark:/13030/qt1wm3w3mn2011-07-03T05:14:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1wm3w3mnMichael GlickmanauthorDohyun KimauthorIra GoldbergauthorJack Judyauthor2006-01-01To enable the field testing of sensors developed by the CENS Sensor group, a sample-preparation and data-acquisition system must be developed. We have found and tested compact, low power valves that use only 5.5mJ per switch, and have been combined into a fluidic multiplexer for calibration. We have made a potentiostat out of a few dollars of chips to replace a large bench top potentiostat that cost $20,000. We have designed a nitrate diffusion system to prevent clogs but still allow nitrate ions to diffuse. Finally, we have created a new board for sensor control and measurement that adds functionality to the previous board and corrects the errors of the old one.publicAutomated Sample Preparation for CENS Embedded Sensors (SEN 7)articlelocaloai:escholarship.org:ark:/13030/qt2h1844r32011-07-03T05:14:49Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2h1844r3Allen HuskerauthorIgor StubailoauthorMartin LukacauthorAlma QuezadaauthorSteven SkinnerauthorIrving FloresauthorPaul DavisauthorRichard GuyauthorDeborah Estrinauthor2006-01-01An overview of Mexican subduction is presented; including young lithosphere, flat slab subduction, and current knowledge of the position of the subducting Cocos and Rivera plates. North of the Trans-Mexican Volcanic Belt (TMVB) those positions become unclear. Geochemical analysis suggests that there may be a slab tear causing mafic volcanism along the northern edge of the (TMVB). A torn slab would suggest that the properties of subduction (i.e. possibly the age of the lithosphere and rate of subduction) have changed since its initiation. Moreover, a stub slab is sufficient to maintain subduction.publicDesign, Installation, and Performance of a Delay Tolerant Seismic Network in Mexico (SEI 1)articlelocaloai:escholarship.org:ark:/13030/qt9jx685wn2011-07-03T05:14:44Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9jx685wnPaul DavisauthorMonica KohlerauthorDeborah EstrinauthorRichard GuyauthorRamesh GovindanauthorIgor StubailoauthorAllen HuskerauthorMartin LukacauthorSam Irvineauthor2006-01-011) The UCLA Factor building is a testbed for predictive numerical modeling, wireless network, and smart event-detection developments related to structural health monitoring. Waveform data from the 72-node array in the 17-story moment-resisting steel frame Factor building are used in comparison with finite element calculations for predictive behavior. 2) We are mapping the subducted slab beneath Mexico and examining slow earthquakes which have been observed at this subduction zone, volcanic earthquakes and the propagation of seismic waves in Mexico City which was devastated in the 1985 Michoacan earthquake. We will compare our 50 instrument wireless array with the 50 instruments of a stand-alone array that has been installed by Caltech. The transect covered by all stations is 500 km long between Acapulco-Mexico City-Tampico.3) We are preparing to move our 50 station array to Peru to compare with Mexico results looking at the flat slab subduction.4) We are developing a low power high resolution wireless seismic array (GeoNet). It is going to be a high density self configuring network that would be possible to deploy in the aftershock zones.publicOverview Embedded Network Approaches to Multiscale Seismic Networks (SEI 3)articlelocaloai:escholarship.org:ark:/13030/qt4kv261jf2011-07-03T05:14:34Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4kv261jfSaurabh GaneriwalauthorDeepak Ganesan (UMass)authorHohyun ShimauthorMani SrivastavaauthorMark Hansenauthor2005-01-01Radio duty cycling has received significant attention in sensor networking literature, particularly in the form of protocols for medium access control and topology management. While many protocols have claimed to achieve significant duty-cycling benefit in theory and simulation, these benefits have often not translated to practice. The dominant factor that prevents the optimal usage of the radio in real deployment settings is time uncertainty between sensor nodes. This poster presents an uncertainty-driven approach to duty-cycling where a model of long-term clock drift is used to minimize duty-cycling overhead.publicSYS4: Estimating Clock Uncertainty for Efficient Duty-Cycling in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt14q943br2011-07-03T05:14:27Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/14q943brHeemin ParkauthorJonathan FriedmanauthorVids SamantaauthorJeff BurkeauthorMani B. Srivastavaauthor2005-01-01We present the Ping-Pong mote, a new light sensing module for the Mica mote platform. The Ping-pong mote achieves performance comparable to a commercial light intensity meter, while conforming to the size and energy constraints imposed by its application in wireless sensor networks. The Ping-pong mote was developed to replace the Mica sensor board (MTS310) whose slow response time and narrow dynamic range in light intensity capture is unsuitable to many applications, including media production. The Ping-pong mote features significantly improved SNR due to its adoption of high-end photo sensors, amplification and conversion circuits coupled with active noise suppression, application-tuned filter networks, and a noise-attentive manual layout.publicA New Light Sensing Module for Mica Motesarticlelocaloai:escholarship.org:ark:/13030/qt3mj9h6752011-07-03T05:14:21Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3mj9h675Yuan YaoauthorYing LinauthorEdward StablerauthorCharles Taylorauthor2005-01-01Vocal individuality is hypothesized to exist in acorn woodpecker. If vocal individuality does exist, certain methods could be developed for individual recognition by acoustic sensor network. This work is to test the hypothesis and to look for efficient methods for vocal individual recognition. Result showed that HMMs can recognize individual birds with high accuracy.publicVocal Individual Recognition of Acorn Woodpecker (Melanerpes formicivorus)articlelocaloai:escholarship.org:ark:/13030/qt4t8446n12011-07-03T05:14:16Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4t8446n1Jillian WallisauthorChristine BorgmanauthorNoel EnyedyauthorStasa Milojevicauthor2005-01-01Having a better understanding of the current data practices on the small, local scale will allow us to build more effective large-scale information systems to support the data practices of the various consumers of CENS data. Some of the practices which need to be understood include what exactly falls under the term data, the sharing practices of the different CENS communities, the current state of intellectual property with regards to data collected as a part of CENS, and then how data should be selected and stored to maximize long-term use and preservation. In trying to understand these issues from the bottom up, an ethnographic study of these practices will lead us closer to choosing appropriate tools and standards to support the long-term viability of the CENS project. This will in turn compliment the top down research into theoretical frameworks for data organization we have previously explored.publicMaking CENS Data Useful to Scientists, Engineers, Studentsarticlelocaloai:escholarship.org:ark:/13030/qt3gd2k2nv2011-07-03T05:14:12Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3gd2k2nvRoy SheaauthorShane MarkstrumauthorMani SrivastavaauthorTodd MillsteinauthorRupak Majumdarauthor2005-01-01This work examines proactive techniques to help developers overcome the difficulty of writing software for the sensor network domain. A framework for static program analysis is used to implement a collection of small "checkers" to verify that programs follow established safety conventions and conform to system resource models. Initial analysis of the SOS code base has revealed interesting errors and helped to pinpoint regions of overly complex program constructs. From this foundation we hope to develop a suite of staged checks to support program development from compile time through execution time.publicProgram Analysis for Reliable Sensor Network Softwarearticlelocaloai:escholarship.org:ark:/13030/qt1nd6p5tg2011-07-03T05:13:47Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1nd6p5tgLaura CormanauthorMichael PetraliaauthorEric WittenmeierauthorJonathan FriedmanauthorDavid LeeauthorMani Srivastavaauthor2005-01-012005 CENS Summer Intern:Autonomous recharging of mobile nodes is crucial to sustaining long-term wireless networks, as well as minimizing the need for human interaction. Charging stations in the field help provide uninterrupted collection of data and decrease human disruption to the area of study. These intelligent charging stations share information and resources both locally and globally to manage multiple power sources among several stations. Charging status is communicated among the stations to optimize the efficiency of the overall system. The charging station design includes multiple methods for station detection, modularity of charging contacts to accommodate different robot platforms, self-healing power management, hermaphroditic linking mechanism, self-correcting mechanical design and various annunciation features. The design was validated against the Ragobot platform.publicRagoDOCSarticlelocaloai:escholarship.org:ark:/13030/qt74w9s1ck2011-07-03T05:13:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/74w9s1ckMadhavan VajapeyamauthorGautam ThatteauthorUrbashi Mitraauthor2004-01-01In this work, communication protocols and encoding schemes are analyzed and designed to achieve diversity and superior probability of decoding error for networks of distributed terminals. In particular, a single source and destination pair are considered with a collection of R cooperating relay nodes in between. Communication protocols and encoding schemes based on methods of amplify-and-forward and decode-and-forward coupled with Alamouti based orthogonal space-time block codes and optimum minimum metric space-time block codes are considered. The achievable diversity of a previously proposed amplify-and-forward/Alamouti method is derived and compared to that of a decode-and-forward scheme. For modest SNRs, the decode-and-forward scheme outperforms the amplify-and-forward based scheme. However, poor source-to-relay link quality can severely impact the decode- and-forward scheme and thus a hybrid scheme is proposed and shown to provide superior performance to the previously two discussed schemes.publicA Hybrid Coding Scheme for Cooperative Networksarticlelocaloai:escholarship.org:ark:/13030/qt0cq3738t2011-07-03T05:13:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0cq3738tKarim SeadaauthorMarco ZunigaauthorAhmed HelmyauthorBhaskar Krishnamachariauthor2004-01-01Recent experimental studies have shown that wireless links in real sensor networks can be extremely unreliable, deviating to a large extent from the idealized perfect-reception-within-range models used in common network simulation tools.publicEnergy-Efficient Forwarding Strategies for Geographic Routing in Lossy Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt2735x02h2011-07-03T05:13:20Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2735x02hFred StannauthorJohn Heidemannauthor2004-01-01Data dissemination in sensor networks requires four components: data resource discovery, route establishment, packet forwarding, and route maintenance. Resource discovery can be the most costly aspect if meta-data does not exist to guide the search. Geographic routing can minimize search cost when resources are defined by location, and hash-based techniques like data-centric storage can make searching more efficient, subject to increased storage cost. In general, however, flooding is required to locate all resources matching a specification. We propose BARD, Bayesian-Assisted Resource Discovery, an approach that optimizes resource discovery in sensor networks by modeling search and routing as a stochastic process. BARD exploits the attribute structure of diffusion and prior routing history to avoid flooding for similar queries. BARD models attributes as random variables and finds routes to arbitrary value sets via Bayesian estimation. Results of occasional flooded queries establish a baseline probability distribution, which is used to focus additional queries. Since this process is probabilistic and approximate, even partial matches from prior searches can still reduce the scope of search.publicBARD: Bayesian Assisted Resource Discoveryarticlelocaloai:escholarship.org:ark:/13030/qt6s15h4k82011-07-03T05:13:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6s15h4k8Roja BandariauthorWendy GwoauthorRachel ScollansauthorRichard PonauthorWilliam Kaiserauthor2004-01-01This poster explains Networked Infomechanical Systems (NIMS) and its applications. In addition, it details the problem of getting accurate location data for the NIMS node and the proposed solution using a separate encoder module.publicReliable Actuation for Networked Infomechanical Systemsarticlelocaloai:escholarship.org:ark:/13030/qt4mf6b32b2011-07-03T05:13:03Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4mf6b32bOmprakash GnawaliauthorMark Yarvisauthor2003-01-01A modern corporate workspace, consisting of matrix of cubicles on a large floor, does not provide isolation from noise from other employees. Noise becomes a distraction when loud sound reaches a person who is working in a cubicle. "Do not disturb" (DND) is a sensor networking application designed to address distracting noise in a corporate workspace. The system alerts people who are talking loud and may be causing distraction to co-workers in neighboring cubicles. DND is an example application for which we designed and built technologies to leverage processing heterogeneity in a sensor network.publicDo Not Disturb: An Application Leveraging Heterogeneous Sensor Networkarticlelocaloai:escholarship.org:ark:/13030/qt6cj1756r2011-07-03T02:21:18Z am 3u Center for Embedded Network SensingVol. 15, no. 4 (Dec. 2005) 359-383eScholarship, University of Californiahttps://escholarship.org/uc/item/6cj1756rBorgman, C Lauthor2005-12-06E-Research is intended to facilitate collaboration through distributed access to content, tools, and services. Findings from two large, long-term digital library research projects are used to illustrate ways in which access to such resources does and does not facilitate collaboration. Both the Alexandria Digital Earth Prototype Project (ADEPT) and Center for Embedded Networked Sensing (CENS) project on data management leverage scientific research data for use in teaching. Two types of collaboration are considered: direct collaboration, in which faculty work together, and indirect or serial collaboration, in which faculty use or contribute shared content such as teaching resources, ontologies, or research data. Implications for collaboration in e-Research are divided into five categories: (1) differences in use based on discipline or specialty, (2) incentives to use e- Learning and e-Research technologies, (3) differences in use of information by role, (4) selecting and sharing of information, and (5) functionality and architecture requirements. Reuse and repurposing of content from research to teaching are proving to be even more complex than anticipated. Better tools and services to manage content can improve capture, management, and preservation. Making content more shareable increases the likelihood that it will be shared. Significant barriers and disincentives to sharing exist, including scientific priority, intellectual property, lack of standards, and the effort to implement systems compared to perceived value. Personal digital libraries offer a middle ground between private control and public release of content. We are just beginning to understand how e-Research can facilitate collaboration. The next step is to understand why.publicWhat Can Studies of e-Learning Teach Us about Collaboration in e-Research? Some Findings from Digital Library Studiesarticlelocaloai:escholarship.org:ark:/13030/qt0sh9338g2011-07-03T02:20:38Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0sh9338gAlberto CerpaauthorJennifer L. WongauthorMiodrag PotkonjakauthorDeborah Estrinauthor2005-01-01Recently, several studies have analyzed the statistical properties of low power wireless links in real environments, clearly demonstrating the differences between experimentally observed communication properties and widely used simulation models. However, these studies have not performed in depth analysis of the temporal properties of wireless links. Our first goal is to study the statistical temporal properties of links in low power wireless communications. We study short term temporal issues, like links lagged autocorrelation, lagged correlation of reverse links, and consecutive same path links. We also study long term temporal aspects, gaining insight on the length of time and how often we should measured the channel and update our models. Our second objective is to explore how statistical temporal properties impact routing protocols. We have developed two new routing algorithms for the cost link model: a generalized Dijkstra algorithm with centralized execution, and a localized distributed probabilistic algorithm.publicTemporal Properties of Low Power Wireless Links: Modeling and Implications on Multi-Hop Routingarticlelocaloai:escholarship.org:ark:/13030/qt7nc5z74x2011-07-03T02:20:17Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7nc5z74xJ. GoldmanauthorD. EstrinauthorW. KaiserauthorG. Pottieauthor2006-01-01publicKNO 0: CENS Knowledge Transfer Overviewarticlelocaloai:escholarship.org:ark:/13030/qt62z4b8dt2011-07-03T02:20:03Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/62z4b8dtDiane BudzikauthorAmarjeet SinghauthorPer Henrik BorgstromauthorMichael StealeyauthorMaxim BatalinauthorWilliam Kaiserauthor2006-01-01Many environmental applications require high fidelity sampling of temporally and spatially distributed phenomena. We propose a MultiScale Sampling approach for efficiently sampling such phenomena. This approach introduces a hierarchy of sensors according to the sampling fidelity, spatial coverage, and mobility characteristics. We report the development of a two-tier MultiScale System where information from a low fidelity, high spatial (global) sensor actuates a mobile robotic node, carrying a high fidelity, low spatial coverage (spot measurement) sensor, to perform guided sampling in regions of high phenomenon variability. As a case study of the proposed MultiScale paradigm, we investigated the spatiotemporal distribution of light intensity in a forest under story. Performance of the MultiScale approach is verified in simulation and on a physical system. We also compare the two most recently used sampling approaches, Adaptive Sampling and MultiScale Sampling, empirically in simulation for both static and spatiotemporally varying phenomenon. Results indicate that MultiScale Sampling is suitable for the sampling of high spatiotemporal frequency varying fields and significantly outperforms Adaptive Sampling.publicMAS 1: Multiscale Sensing and Actuation Architecture and Performancearticlelocaloai:escholarship.org:ark:/13030/qt2233b9pd2011-07-03T02:19:53Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2233b9pdRamakrishna GummadiauthorNupur KothariauthorRamesh GovindanauthorTodd Millsteinauthor2006-01-01We are pursuing a new approach to programming sensor networks that significantly raises the level of abstraction over today's practice. The critical change is one of perspective: rather than writing programs from the point of view of an individual node in the network, programmers implement a central program that conceptually has access to the entire network. This pushes to the compiler the task of producing equivalent node-local programs that implement this behavior.In this poster, we outline the design of the Kairos programming language, its compiler, and its runtime system. The Kairos language extends the C language, and it includes new language constructs that allow programmers to declaratively access node-local state within the network and to specify simple forms of concurrent execution. The Kairos compiler employs a novel program analysis to automatically compile Kairos programs to node-local programs written in nesC. Finally, the runtime system executes these node-local programs in an energy-efficient manner on top of TinyOS on the Berkeley motes. It also employs novel locking and deadlock-detection algorithms to ensure serializability in the presence of concurrency.publicKairos: Reliable and Efficient Programming Abstractions for Sensor Networks (SYS 4)articlelocaloai:escholarship.org:ark:/13030/qt56v1c40b2011-07-03T02:19:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/56v1c40bSarah RothenbergauthorJenny Jayauthor2006-01-01Mugu Lagoon is a coastal estuary, located entirely within the Pt. Mugu Naval Air and Weapons Station in Ventura County, about 45 miles north of UCLA. In 1996, Mugu was listed by the State Water Quality Control Board as impaired for mercury, a potent neurotoxin, which is accumulated and biomagnified in the aquatic food web. In 2005, we completed a study on mercury methylation at 10 sampling sites at Mugu, within four habitats at most sites, in the winter and summer. Our results indicated mercury methylation is comparable across the estuary, and there were no seasonal differences; however, significantly higher yields of methylmercury were observed in marsh habitats, compared to other habitats. This winter we will deploy a sensor network at one sampling site within the marsh, to further investigate the biogeochemical controls on mercury cycling. Using an embedded sensor networked array, we will determine under which hydrologic and biogeochemical regimes methylmercury yields are highest. These dense temporal data may be used to determine schemes for "smart sampling," that is, when the conditions are most conducive for mercury methylation.publicA proposed sensor deployment to investigate biogeochemical controls on mercury cycling in Mugu Lagoon, California (CON 5)articlelocaloai:escholarship.org:ark:/13030/qt9jh6n6142011-07-03T02:19:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9jh6n614Gong ChenauthorAndrew ParkerauthorSasank Reddyauthor2006-01-01We envision the blossoming of citizen initiated sensing applications in an urban context, enabled by increasingly affordable and portable sensing hardware, and ubiquitous wireless access to communication infrastructure. The Partisans architecture features infrastructure-supported selective data sharing, verification, and storage services. This effort represents an evolution of activity on embedded networked sensing from the scientific application space to applications in a space that raises novel issues in privacy, security, and interaction with the Internet.publicPartisan (SYS 24)articlelocaloai:escholarship.org:ark:/13030/qt2p13n8md2011-07-03T02:19:22Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2p13n8mdBradley BennettauthorAlberto CerpaauthorJessica FengauthorFarinaz KoushanfarauthorRichard ParkauthorThomas SchoellhammerauthorJennifer L. WongauthorMiodrag Potkonjakauthor2005-01-01We address two of the canonical problems in sensor networks: data integrity and computational sensing. Due to the large scale and distributed nature of sensor networks, their heterogeneous node structure, cost and power constraints, operation in unpredictable and unconditioned (and often harsh) environmental surroundings and inherent unreliability of sensors sensor networks often collect data with errors, faults and missing samples. We have developed a generic approach for both tasks that has three phase: (i) statistical modeling, (ii) prediction, and (iii) fusion and analysis.publicSIP5: Understanding and Controlling Instrumented Physical Systems:Modeling is Complex, but Optimization is Easyarticlelocaloai:escholarship.org:ark:/13030/qt6b38n1jh2011-07-03T02:19:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6b38n1jhH. WangauthorC. E. ChenauthorA. AliauthorS. AsgariauthorR.E. HudsonauthorK. YaoauthorD. EstrinauthorC. Taylorauthor2005-01-01In this poster, we describe the 2-D acoustic array design for robust acoustic beamforming used in woodpecker localization sensor networks. Although woodpecker calls are not narrow-band signals, due to the rugged spectral power density of woodpeckers, the beampattern of the 2-D acoustic array has side lobes that are nearly as tall as the main lobe. With strong multi-path effects of sound propagation in the woods, the sidelobe can easily grow taller than the main lobe and thus causes large error in the beamforming based target direction estimation. We propose to choose the microphone spacing in the 2-D acoustic array according to the narrow-band beamforming of the dominant frequency of the woodpecker calls. This design greatly improves the robustness of target direction estimation using acoustic beamforming.publicAcoustic Sensor Networks for Woodpecker Localizationarticlelocaloai:escholarship.org:ark:/13030/qt60h3h1h42011-07-03T02:18:48Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/60h3h1h4Wang, H BauthorYao, KauthorPottie, GregoryauthorEstrin, Dauthor2003-11-05Entropy based sensor selection heuristics is proposed for localization applications. Given 1) the prior target location distribution, and 2) the location and sensing uncertainty of a set of sensors, the heuristics selects a sub optimal sensor whose measurement would yield nearly the greatest uncertainty reduction of the target location probability distribution. The heuristics defines the potential of a sensor to reduce target location distribution uncertainty. The potential is positively proportional to the entropy of the sensors view of the target location distribution. The potential is negatively proportional to the sensors sensing uncertainty. All candidate sensors potential are evaluated without retrieving actual sensor measurements. The heuristics is illustrated with a localization case study in which bearing sensors, range sensor and time difference sensors are used.publicMultiscaled Actuated SensingEntropy Based Sensor Selection Heuristic for Localizationarticlelocaloai:escholarship.org:ark:/13030/qt9dr4z3zt2011-07-03T02:17:51Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9dr4z3ztXin LiauthorYoung Jin KimauthorRamesh GovindanauthorWei Hongauthor2003-01-01In many sensor network applications, data or events are named by attributes. Many of these attributes have scalar values, so one natural way to query events of interest is to use a multi-dimensional range query. An example of such a range query is: ’¡Èlist all events whose temperature lies between 50 degree and 60 degree, and whose light levels lie between 10 and 15. Such queries are useful for correlating events occurring within the network represented by different attribute values. In this demo, we will demonstrate an implementation of a distributed index that scalably supports multi-dimensional range queries. Our distributed index for multi-dimensional datapublicDistributed Index for Multi-dimensional Data in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt7z37w3qq2011-07-02T23:00:20Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7z37w3qqKarthik DantuauthorGauravauthor2003-01-01We present an algorithm that detects and traces a contour of a scalar field. A set of static sensor nodes are deployed in a given area. The algorithm causes a mobile sensor node to approach a given contour. The algorithm uses local communication between the mobile node and its immediate neighbors only. Also, the path generated by the mobile node is near optimal when the static nodes are deployed at reasonable densities (avg. degree of about six).publicBoundary Detection Using Actuated Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt6b67b1b92011-07-02T23:00:16Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6b67b1b9Laura BalzanoauthorNithya RamanathanauthorTom Sc hoellhammerauthorDeborah EstrinauthorEddie KohlerauthorMani Srivastavaauthor2006-01-01We aim to design a high fidelity collection process that primarily aims to design human interaction into the system to do two things: first, diagnose and/or fix problems that the system cannot address automatically, and second, gather extra sensory observations, such as physical samples, that provide contextual information useful for determining data integrity and easing data analysis. We believe that carefully integrating human input into the collection path will facilitate collection of datasets that are more useful than completely autonomously collected data.publicHigh Fidelity Data Collection: Managing the Collection Process Throughout the Deployment Lifecycle (SYS 19)articlelocaloai:escholarship.org:ark:/13030/qt2s61c9t62011-07-02T23:00:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2s61c9t6Alexander RatkoauthorThomas HarmonauthorChristopher ButlerauthorTatyana BendikovauthorYair WisjboomauthorMichael Bendikovauthor2006-01-01Nitrate pollution of groundwater is often the result of non-point sources of nutrients or livestock waste. Thus, the notion of a technology that would enable us to efficiently yet economically monitor for nitrate in a distributed fashion is an attractive one. Taking into account the advantages of potentiometry as an electroanalytical method, many efforts have been undertaken to develop reliable ion-selective electrode (ISE) suitable for the determination of nitrate at low concentrations while exhibiting good selectivity for nitrate over potentially interfering anions (chloride, nitrite, hydrocarbonate, perchlorate, thyocyanate and etc.). This work reports on the development and applications of a stable solid state nitrate microsensor based on doped polypyrrole films. We have developed a miniature and inexpensive nitrate sensor by electropolymerizing pyrrole on a surface of pencil leads, using nitrate as a dopant. Pencil leads were found to be a good substitute to expensive conductive materials, such as glassy carbon and platinum.publicScaleable nitrate sensors for soil and water observation applications (SEN 6)articlelocaloai:escholarship.org:ark:/13030/qt5kn4c8f62011-07-02T23:00:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5kn4c8f6Tatyana Bendikov (UCLA)authorNicole Jurisch (U Wash)authorMallory Davidson (U Wash)authorThomas Harmon (UCM)author2005-01-01This work describes the development and testing of a sensitive and selective potentiometric nitrate microsensor that are scaleable to large, dense sensor networks required to study environmental systems. We have developed flexible, miniature and inexpensive nitrate sensors by electropolymerizing pyrrole onto carbon fiber substrates, using nitrate as a dopant. Carbon microfibers were found to be an excellent substitute to expensive conductive materials, such as glassy carbon or platinum.publicSEN3: Potentiometric Nitrate Sensors in the Form of Plant Rootsarticlelocaloai:escholarship.org:ark:/13030/qt8kf9p6792011-07-02T23:00:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8kf9p679Deborah EstrinauthorRamesh GovindanauthorRichard GuyauthorJohn HeidemannauthorEddie KohlerauthorTodd MillsteinauthorJens PalsbergauthorMiodrag PotkonjakauthorMani Srivastavaauthor2005-01-01publicSYS0: Systems Area Research Overviewarticlelocaloai:escholarship.org:ark:/13030/qt6jn6h6xj2011-07-02T22:59:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6jn6h6xjNithya RamanathanauthorEddie KohlerauthorDeborah Estrinauthor2005-01-01Being embedded in the physical world, sensor networks present a wide range of bugs and misbehavior qualitatively different than those in most distributed systems. Unfortunately, due to resource constraints, programmers must investigate these bugs with only limited visibility into application behavior. We need a new approach. This poster presents the design and evaluation of Sympathy, a tool for detecting and debugging failures in pre- and post-deployment sensor networks. Sympathy consists of mechanisms for reporting generic system and application metrics; mechanisms for identifying conditions based on these metrics; a simple debugging algorithm to detect failures based on the conditions; and a system for logging metrics and events in their spatiotemporal context.publicSYS5: Sympathy for the Sensor Network Debuggerarticlelocaloai:escholarship.org:ark:/13030/qt5dk877x52011-07-02T21:21:17Z am 3u Center for Embedded Network SensingVol. 36, no. 4 (Jan. 2006) 63-74eScholarship, University of Californiahttps://escholarship.org/uc/item/5dk877x5Rangwala, SumitauthorGummadi, RamakrishnaauthorGovindan, RameshauthorPsounis, Konstantinosauthor2006-01-01In a wireless sensor network of N nodes transmitting data to a single base station, possibly over multiple hops, what distributed mechanisms should be implemented in order to dynamically allocate fair and efficient transmission rates to each node? Our interferenceaware fair rate control (IFRC) detects incipient congestion at a node by monitoring the average queue length, communicates congestion state to exactly the set of potential interferers using a novel low-overhead congestion sharing mechanism, and converges to a fair and efficient rate using an AIMD control law. We evaluate IFRC extensively on a 40-node wireless sensor network testbed. IFRC achieves a fair and efficient rate allocation that is within 20–40% of the optimal fair rate allocation on some network topologies. Its rate adaptation mechanism is highly effective: we did not observe a single instance of queue overflow in our many experiments. Finally, IFRC can be extended easily to support situations where only a subset of the nodes transmit, where the network has multiple base stations, or where nodes are assigned different transmission weights.publicSystemsCongestion ControlRate ControlFairnessWirelessIFRCSensor NetworkInterference-Aware Fair Rate Control in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt4hc0w3ct2011-07-02T21:20:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4hc0w3ctJessica FengauthorLewis GirodauthorMiodrag Potkonjakauthor2006-01-01We propose a new error modeling and optimization-based localization approach for sensor networks in presence of range measurement errors. The approach is solely based on the concept of consistency. The error models are constructed using non-parametric statistical techniques; they do not only indicate the most likely error, but also provide the likelihood distribution of particular errors occurring. The models are evaluated using the learn-and-test method and served as the objective functions for the task of localization. In addition, we also developed a localized localization algorithm where a specified communication cost or the location accuracy is guaranteed while optimizing the other.publicConsistency-based Localization in Sensor Networks (MAS 9)articlelocaloai:escholarship.org:ark:/13030/qt0rf530hg2011-07-02T21:20:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0rf530hgRichard GuyauthorJohn HicksauthorKaren Weeksauthor2006-01-01The Systems Infrastructure team assembles, tests, and provides complete sensor network solutions containing both exploratory and hardened components, from high-level applications and analysis tools, down to hardware at the sensor platform level. Recent significant progress is seen in SensorBase and ESS2 at the database and application levels; in disruption-tolerant data delivery and system control software and in the integration of the latest wireless routing algorithms.publicSystems Infrastructure (SYS 18)articlelocaloai:escholarship.org:ark:/13030/qt7886j2pz2011-07-02T21:20:36Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7886j2pzKathy GriffisauthorJoe Wiseauthor2006-01-01We are working with CENS field biologists and computer scientists/engineers to explore Cyclops camera applications. We are testing whether the Cyclops can serve as a spectrophotometer in detecting the color changes in leaves due to nutrient stress as well as its appropriateness for recording plant growth rates.publicField Application of Cyclops (EDU 3)articlelocaloai:escholarship.org:ark:/13030/qt4d9454v12011-07-02T21:20:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4d9454v1Jason C. FisherauthorHenry PaiauthorThomas C. Harmonauthor2006-01-01Increasing demands on water supplies, non-point source pollution, and water quality-based ecological concerns all point to the need for observing stream flow perturbations and pollutant discharges at higher resolution than was practical in the past. This poster presents a demonstration of the following multiscale ENS approach to observing water quality changes in a regional river network. First, agency gauging station data are used to identify reservoir operations-related flow conditions throughout the region, allowing rough identification of potential trouble spots along the rivers in terms of the flow, temperature and salinity observations. Next, in-field analysis commences with human-actuated nodes in river kayaks characterize the river geometry, bathymetry and water quality at the potential trouble spotspublicA Multiscale Embedded Networking Sensing Water Quality Observatory Study at the Merced and San Joaquin Rivers' Confluence (CON 3)articlelocaloai:escholarship.org:ark:/13030/qt1w58z61k2011-07-02T21:20:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1w58z61kAlberto PepeauthorJillian C. WallisauthorMatthew MayernikauthorChristine L. Borgmanauthor2006-01-01At CENS, practices for data handling vary widely across research groups and projects. The lack of a common set of policies and procedures affects the entire data production life cycle: from data acquisition, for sensor data get encoded in different (possibly incompatible) formats to data dissemination. Internal circulation is performed via shallow methods such as email communication or static FTP transmission. This sort of data management setting does not stimulate data exchange, indicating the need for a common infrastructure capable of enforcing interoperability. We propose adoption of standard, XML-based formats, such as SensorML and EML, to encode sensor data instances and describe detector information; compliance to standard formats enables data reuse across different projects and guarantees long-term preservation. Moreover, we envision utilization of interoperable protocols, such as OAI-PMH, to encapsulate data objects onto an application-independent framework and thus ease collection and dissemination with external research institutions.,#8194;,#8194;,#8194;publicDevising an infrastructure for data interoperability (KNO 4)articlelocaloai:escholarship.org:ark:/13030/qt40q552q42011-07-02T21:20:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/40q552q4BA StaufferauthorSD MoorthiauthorB ZhangauthorA DhariwalauthorC ObergauthorA Menezes-PereiraauthorDA CaronauthorGS Sukhatmeauthor2006-01-01The Networked Aquatic Microbial Observing System (NAMOS) is an array of embedded networked sensors that has been developed to study plankton populations in marine and aquatic environments. The application of NAMOS in Lake Fulmor, adjacent to the James Mountain Reserve, California, has begun to yield valuable insights into plankton community structure and dynamics including the spatial and temporal distributions of phytoplankton throughout the lake, and their adaptive strategies to deal with extremely high light intensities in surface waters of this subalpine lake. Data collected during deployments of NAMOS in May, June, and August, 2006 revealed changes in vertical temperature stratification, accompanied by overall increases in chlorophyll in the lake throughout the three deployments. The phytoplankton community structure was also highly variable for the three deployments, with diatoms, dinoflagellates, and cyanobacteria dominating at different times, most likely as temperature stratification, nutrient concentrations, and light regimes underwent seasonal changes.publicCharacterization of the phytoplankton community and photoadaptive strategies in Lake Fulmor, CA established through embedded networked sensing. (AQU 1)articlelocaloai:escholarship.org:ark:/13030/qt4wt0v46m2011-07-02T21:20:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4wt0v46mTyler McHenryauthorJohn Heidemannauthor2005-01-012005 CENS Summer Intern:Experimentation in medium access control (MAC) protocols for wireless sensor networks cannot be accomplished completely within simulation. Live testing of MAC protocols requires analysis of active, live networks of motes. To gain a picture of the running network, researchers to this point have relied on embedding code within the motes themselves to report status and crude data loggers to collect the data. However, the side effects of embedded debug code may adversely affect an experiment, and collection of raw data is unwieldy and slow to process. Our goal is to provide a non-intrusive and user friendly system for analyzing traffic on active sensor networks which, through creative inference and post-processing, can report to the same level of as embedded debugging code without any side effects on the network. It is important that the software is also adaptive and extensible enough to allow researchers to test changes to their MAC protocol without having to modify the analysis tool or add a new protocol to the framework painlessly. The initial application of this research is to aid in the optimization of MAC protocols for high-density sensor networks.publicNon Intrusive Analysis of Sensor Network MAC Protocolsarticlelocaloai:escholarship.org:ark:/13030/qt3vw6n0fm2011-07-02T21:19:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3vw6n0fmHenri Dubois FerriereauthorLewis GirodauthorDeborah Estrinauthor2003-01-01A common scenario for sensor networks is data-gathering: nodes gather data (periodically, or triggered by certain conditions) and send it back to a sink (or basestation). Data is sent over multiple hops, using a tree topology. Such a system with a single sink presents scaling difficulties as the network grows: the average distance to the sink increases, and nodes near the top of the tree must relay a disproportionate amount of traffic. Placing multiple sinks (basestations) can alleviate this, but on the other hand introduces additional overhead if all sinks flood the entire network. Voronoi scoping is a simple distributed technique to limit floods so that each flood reaches only the subset of nodes in the originating sinks region; that is the nodes who have the originator as closest sink. We have implemented the algorithm in one-phase pull; this demo uses emview to visualize in real-time the clusters formed in the LECS lab ceiling array of motes.publicVoronoi Scoping in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt7q60k5d32011-07-02T21:19:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7q60k5d3Lewis GirodauthorAlberto CerpaauthorHenri Dubois-Ferriereauthor2003-01-01Em View is an extensible visualization system that integrates to emstar-based systems, simulators, and emulators. It can also be connected via gateways and other means to other systems. Em View grew out of a need to develop a unified visualization system to replace a host of individually developed single-application visualizers. Thus, Em View is designed specifically to visualize a wide range of applications from a single reusable framework. A highly customizable interface enables multiple visualization schemes to coexist in a single display, while a simple API significantly reduces the coding required to develop new application specific visualization modules.publicEm View: The Em* Visualizerarticlelocaloai:escholarship.org:ark:/13030/qt6xt4d2702011-07-02T21:16:32Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6xt4d270Zhang, HongweiauthorNaik, Vinayak Sauthor2008-02-28Dynamics of wireless communication, resource constraints, and application diversity pose significant challenges to data transport control in wireless sensor networks. In this chapter, we examine the issue of data transport control in the context of two typical communication patterns in wireless sensor networks: convergecast and broadcast. We study the similarity and differences of data transport control in convergecast and broadcast, we discuss existing convergecast and broadcast protocols, and we present open issues for data transport control in wireless sensor networks.publicSystemsSensorswirelesssesnor networksroutingbroadcastreprogrammingreliableenergy efficientlink layerTDMACSMAData Transport Control in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt8ct2h4pk2011-07-02T21:13:06Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8ct2h4pkJerry ZhaoauthorR. Govindanauthor2003-01-01publicUnderstanding Packet Delivery Performance In Dense Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt7vd511342011-07-02T21:13:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7vd51134D. GanesanauthorS. RatnasamyauthorH. WangauthorD. Estrinauthor2003-01-01publicCoping with Irregular Spatio-Temporal Sampling in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt0fc6s47m2011-07-02T21:11:29Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0fc6s47mQing HeauthorChanglin PangauthorYu-Chong TaiauthorTerry Leeauthor2004-01-01publicIon Liquid Chromatography System On-a-Chip with Beads-Packed Parylene Columnarticlelocaloai:escholarship.org:ark:/13030/qt4354f19z2011-07-02T21:06:17Z am 3u Center for Embedded Network SensingVol. 4026 (Jan. 2006) 529-545eScholarship, University of Californiahttps://escholarship.org/uc/item/4354f19zFeng, JessicaauthorGirod, LewisauthorPotkonjak, Miodragauthor2006-01-01We have developed a new on-line error modeling and optimization-based localization approach for sensor networks in the presence of distance measurement noise. The approach is solely based on the concept of consistency, and is developed specifically for the case of on-line localization, which refers to the situation when references are not available a priori. The localization problem is formulated as the task of maximizing the consistency between measurements and calculated distances. In addition, we also present a localized localization algorithm where a specified communication cost or the location accuracy is guaranteed while optimizing the other. We evaluated the approach in (i) both GPS-based and GPS-less scenarios; (ii) 1-D, 2-D and 3-D spaces, on sets of acoustic ranging-based distance measurements recorded by deployed sensor networks. The experimental evaluation indicates that localization of only a few centimeters is consistently achieved when the average and median distance measurement errors are more than a meter, even when the nodes have only a few distance measurements. The relative performance in terms of location accuracy compares favorably with respect to several state-of-the-art localization approaches. Finally, several insightful observations about the required conditions for accurate location discovery are deduced by analyzing the experimental results.publicMultiscaled Actuated SensingConsistencyLocation DiscoveryStatistical ModelingConsistency-Based On-line Localization in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt1km520ps2011-07-02T21:05:21Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1km520psHamilton, Michaelauthor2006-12-04publicTerrestrialEmbedded Networked Sensing in Terrestrial Ecosystemsarticlelocaloai:escholarship.org:ark:/13030/qt7gx0q9742011-07-02T21:05:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7gx0q974Kim, JuyoulauthorBendikov, TatyanaauthorPark, YeonjeongauthorHarmon, T Cauthor2003-04-06This work examines the potential role of embedded, networked sensing (ENS) protocols in monitoring the fate and transport of contaminants in the subsurface. The ultimate goal is to deploy a large dense array of chemical sensors for the purpose of identifying key transport parameters that are spatially distributed (e.g., porous media dispersivity) and, in some cases, temporally varying (e.g., nonaqueous phase liquid source zones). While there is clearly a need for further development in chemical sensor technology, the need to prepare to deploy new sensors in distributed networks is equally great. In this work, we first examine heat transfer phenomena as a surrogate for mass transfer in an intermediate scale physical aquifer model. Using a relatively standard data acquisition system (National Instruments A/D converter with Labview software), we continuously monitor water temperature over time and space throughout the model system. For well-defined heat sources, we developed closed-form solutions to the governing differential equations that are suitable for analyzing our data. Then, by embedding these closed solutions into our data acquisition routines, we were able to identify phenomenological parameters in real-time. Moving toward more relevant systems, we next demonstrate the use of a single nitrate sensor placed down-gradient of a finite pulse source of nitrate in a three-dimensional porous medium. Other potential applications and implications of ENS protocols in environmental monitoring networks will be discussed in terms of supporting ENS issues of self-adaptation, self- calibration, and coordinated actuation of responses.publicContaminant TransportNetworked Sensing in Support of Real-Time Transport Model Parameter Estimationarticlelocaloai:escholarship.org:ark:/13030/qt62p283712011-07-02T21:04:48Z am 3u Center for Embedded Network SensingVol. 11, no. 1 (Feb. 2003) 2-16eScholarship, University of Californiahttps://escholarship.org/uc/item/62p28371Intanagonwiwat, ChalermekauthorGovindan, RameshauthorEstrin, DauthorHeidemann, JohnauthorSilva, Fabioauthor2003-02-25Advances in processor, memory, and radio technology will enable small and cheap nodes capable of sensing, communication, and computation. Networks of such nodes can coordinate to perform distributed sensing of environmental phenomena. In this paper, we explore the directed-diffusion paradigm for such coordination. Directed diffusion is data-centric in that all communication is for named data. All nodes in a directed-diffusion-based network are application aware. This enables diffusion to achieve energy savings by selecting empirically good paths and by caching and processing data in-network (e.g., data aggregation). We explore and evaluate the use of directed diffusion for a simple remote-surveillance sensor network analytically and experimentally. Our evaluation indicates that directed diffusion can achieve significant energy savings and can outperform idealized traditional schemes (e.g., omniscient multicast) under the investigated scenarios.publicSystemsdata aggregationdata-centric routingdistributed sensingin-network processingwireless sensor networksomniscient multicastremote-surveillancedirected diffusiondistributed sensorsradio networksremote sensingsensor fusionsurveillancetelecommunication network routingDirected Diffusion for Wireless Sensor Networkingarticlelocaloai:escholarship.org:ark:/13030/qt5v7619xw2011-07-02T21:02:47Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5v7619xwGoldman, JeffauthorRamanathan, NithyaauthorAmbrose, Richard FauthorCaron, DavidauthorEstrin, DauthorFisher, JasonauthorGilbert, RobertauthorHansen, MarkauthorHarmon, T CauthorJay, J AauthorKaiser, W JauthorSukhatme, GauravauthorTai, Yu-Chongauthor2007-02-01The exponential progress of technology development, driven in many cases by Moore’s Law, has enabled the combination of sensing, computation and wireless communication in small, low-power devices that can be embedded directly in the physical environment. Recent research has resulted in several new classes of embedded networked sensing systems that can be rapidly distributed in the environment to study phenomena with unprecedented detail. Embedded networked sensing systems are transforming the way in which physical, biological and chemical changes are detected and quantified. These results are leading to new mechanistic understanding of the environment and, consequently, to new models and predictions for better assessment and management of environmental challenges.This white paper describes the emerging technologies used in distributed sensing systems and the opportunities these systems present for environmental management, and in particular, water quality protection. A team of faculty, students, and staff at the Center for Embedded Networked Sensing (CENS) wrote the report. CENS is a National Science Foundation sponsored Science and Technology Center, headquartered at the University of California, Los Angeles (UCLA). In addition to UCLA, the California Institute of Technology, the Riverside and Merced campuses of the University of California, and the University of Southern California are partners in the center. CENS is developing embedded networked sensing systems and applying this technology to critical scientific and social applications. The Foresight and Governance Project at the Woodrow Wilson International Center for Scholars edited and finalized this document for the U.S. Environmental Protection Agency’s Office of Water.This paper first briefly describes the potential applications of sensing systems to four common water quality management problems. This potential includes: (1) providing early warning for septic systems, (2) allowing for the trading of credits for non-point source runoff, (3) monitoring beach water quality, and (4) management of combined sewer overflows. Section 4 describes these scenarios in further detail.Section 1 provides an overview of sensors (i.e., the devices that convert environmental phenomena into an electronic response) and actuators (i.e., the devices that convert electrical signals into mechanical responses). Sensors have the potential to detect physical, chemical, biological, and radiation properties in the environment. A variety of sensors is currently available for networked environmental sensing, while others are still in early research and development phases. Physical sensors for water quality monitoring are generally the most field-ready and scalable to distributed applications, followed by chemical and then biological sensors. The costs for these sensors depend on the physical, chemical, or biological parameter of interest. Indicator sensors and event-triggering sampling can be used when direct detection sensors are not ready for field deployment. To more extensively detect environmental properties, even more sophisticated sensors and sensing strategies are needed, including: (1) hardening novel sensors types (such as lab-on-a-chip technology) to withstand harsh conditions for extended periods, and (2) devising integrated sensing systems for higher order observations, such as quantifying materials fluxes in the environment.Section 2 on Deployment Platforms discusses three new sensing system classes: static, mobile robotic, and mobile handheld. These sensing systems differ from traditional measurement systems in that sensors are attached to wireless radios that enable real-time communication of the data collected. For any particular situation, the best system class to use depends on the environment’s spatial and temporal variation. Among the three classes of sensing systems, mobile handheld systems are best used when the environmental phenomena of interest cover a broad area and do not require great spatial resolution. Static sensing systems are best used over smaller areas when high spatial resolution is not required, and mobile robotic systems are appropriate for intensive measurement of very small areas. To improve overall sensing efficiency (e.g., time or cost), adaptive sampling allows the system to dynamically adjust its measurement location or frequency to meet spatial or temporal variation in the environment. Sensing platforms can also be combined such that different platforms can provide information at different scales. This type of multi-scale system can also often help improve the efficiency of a monitoring effort. Despite the opportunities these sensing systems present, the ability to deploy them in the field can be limited by power availability and faults that interfere with communication or sensing hardware.To help address some of the challenges facing the effective implementation of sensing systems and the interpretation of the acquired data, section 3 discusses the usefulness of considering the entire “life cycle” of data in a sensing system. This life cycle consists of three distinct phases: design and deployment of the observing system; operation and monitoring; and analysis, modeling and data sharing.The final section of the report offers recommendations for future research. In spite of the substantial success in research and development activities that has given rise to existing sensing systems, relatively few have been deployed in real-world applications. The time is ripe to expand the range of applications where embedded sensing systems are used. Some of the key recommendations outlined in section 5 for novel uses of embedded sensing systems include: Sensors and Actuators • (1) Long-term research and development for sensors where new or improved detection methods are needed and (2) short-term market incentives targeted at moving already well-developed sensing technology from research prototypes (e.g., biological and chemical sensors) to commercially available products. • Long-term research to develop detection methods for carbonaceous compounds, heavy metals, large molecular mass molecules such as dissolved organic compounds and dissolved organic nitrogen compounds, pathogenic organisms, biologically-active compounds, biomarkers, and lab-on-achip sensors. • Research on methods to minimize sensor maintenance in the field. • Investments to bring prototype technologies, such as small robust nitrate sensors that can be deployed for long periods, to market in forms suitable for environmental sensing. Deployment Platforms • Investments in a range of pilot studies to determine specific deployment and analysis methodologies for target systems (e.g., septic system or sewage discharge monitoring). • Definition of requirements of large scale uses of the technology to encourage the production of user-friendly systems. The Data Life Cycle • The encouragement of pilot deployments to test and refine data management tasks for specific applications. • Continued research and testing of tools to improve system robustness and ensure high-quality data. • Additional focus on the integration of sensing systems with external data sources and third-party applications, especially map-based visualization with tools for both rigorous GIS techniques and more public friendly web applications. Training • Training at multiple levels (school systems and professional development) to ensure that a ready workforce exists that is prepared to use these new sensing technologies.Embedded networked sensing systems will form a critical infrastructure resource for society—they will monitor and collect information on such diverse subjects as plankton colonies, endangered species, soil and air contaminants, medical patients, and buildings, bridges and other manmade structures. Investments in further research to help bring the sensing technologies discussed in this report into practice will transform the way we monitor and manage the health of our natural resources and predict and respond to crises.publicDistrbuted Sensing Systems for Water Quality Assesment and Managementarticlelocaloai:escholarship.org:ark:/13030/qt9q5244gn2011-07-02T21:01:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9q5244gnHeemin ParkauthorMani B. Srivastavaauthor2003-01-01This paper presents an energy-efficient task assignment and migration framework for sensor networks.publicEnergy-Efficient Task Assignment Framework for Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt6359f69q2011-07-02T21:01:35Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6359f69qNorman Makoto SuauthorHeemin ParkauthorEric BostromauthorJeff BurkeauthorMani B. SrivastavaauthorDeborah Estrinauthor2003-01-01In this paper, we describe our implementation of a system to augment film and video footage with sensor data.publicAugmenting Film and Video Footage with Sensor Dataarticlelocaloai:escholarship.org:ark:/13030/qt4kw5x35z2011-07-02T21:01:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4kw5x35zSaurabh GaneriwalauthorRam KumarauthorMani B. Srivastavaauthor2003-01-01The paper proposes a protocol for network wide time synchronization in sensor networks.publicTiming-sync protocol for sensor networksarticlelocaloai:escholarship.org:ark:/13030/qt0s17w7fc2011-07-02T21:01:06Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0s17w7fcAman KansalauthorMani Srivastavaauthor2003-01-01This work describes how environmental energy can be managed in a distributed system to maximize performance. Based on the authors'' ACM/IEEE ISLPED 2003 paper.publicAn Environmental Energy Harvesting Framework for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt77d882tk2011-07-02T21:01:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/77d882tkMohammad RahimiauthorRichard PonauthorDeborah EstrinauthorWilliam J. KaiserauthorMani SrivastavaauthorGaurav S. Sukhatmeauthor2003-01-01This paper introduces NIMS as Networked InfoMechanical Systems and describes new semantic of adaptive sampling for environmental robotics to cope with irregularities of the phenomena.publicAdaptive Sampling for Environmental Roboticsarticlelocaloai:escholarship.org:ark:/13030/qt7fs3g0c52011-07-02T21:00:47Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7fs3g0c5Tatyana A. BendikovauthorThomas C. Harmonauthor2005-01-01This work describes the development and fabrication of stable potentiometric solid state sensors for the perchlorate ion (ClO4-) based on doped poly(3,4-ethylenedioxythiophene) (PEDOT) films. PEDOT, one of the most promising conducting polymers, is extremely stable in its oxidized state. Using PEDOT(ClO4-) films as sensing material in ion selective electrodes presents a unique opportunity to create sensors having a longer lifetime compared to analogous sensors, such as those created using doped polypyrrole. Over the eight month period of this study, the PEDOT(ClO4-) sensors exhibited a stable, linear response spanning at least five orders of magnitude in concentration (1 M – 1 × 10-5 M perchlorate) with near-Nernstian slopes approaching -50 mV/decade of ClO4- concentration and a limit of detection of 5 × 10-6 M. Carbon fibers and pencil leads were employed as alternative and inexpensive substrates for EDOT polymerization, addressing problems with the sensor`s form (miniature size, flexibility) and cost.publicLong-lived solid state perchlorate ion selective sensor based on doped poly(3,4-ethylenedioxythiophene) (PEDOT) filmsarticlelocaloai:escholarship.org:ark:/13030/qt3v07x98q2011-07-02T21:00:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3v07x98qAmeesh PandyaauthorAman KansalauthorGregory PottieauthorMani Srivastavaauthor2004-01-01Sensor networks collect data at multiple distributed nodes and transfer the acquired information to points of interest. The raw data collected by each individual sensor is typically not of interest. Instead, a reduced representation of the measured phenomenon is to be generated. Multiple readings, however, add to the information about the phenomenon by providing its description at multiple points in space for distributed phenomena and multiple perspectives for a localized phenomenon. We also note that sensor readings have noise, and multiple readings can help mitigate the effect of this noise. Thus, while all the sensor readings need not be communicated, enough data must be exchanged to reliably reproduce the phenomenon. Considering the above effects, it becomes important to determine how much data should be transmitted from multiple sensors such that only useful information is exchanged and energy or bandwidth are not wasted on redundant data. We address this question using information theoretic techniques. The effects of sensor noise and correlation in the sensor readings are explicitly modelled.publicFidelity and Resource Sensitive Data Gatheringarticlelocaloai:escholarship.org:ark:/13030/qt53j476232011-07-02T21:00:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/53j47623Amarjeet SinghauthorMaxim BatalinauthorMichael StealeyauthorVictor ChenauthorMark H HansenauthorThomas C HarmonauthorGaurav S. SukhatmeauthorWilliam J. Kaiserauthor2006-01-01This paper reports the first application of actuated sensing systems for high spatiotemporal resolution characterization of the threedimensional environment of river and lake aquatic systems. The development of a new method and its verification in these two application areas is described. Both applications involve dynamic phenomena - one resulting from flow of the water and the other from rapidly evolving biological processes. These applications are typical environmental monitoring problems. They exemplify the key challenge in such problems - characterizing phenomena displaying spatiotemporal heterogeneity. In many such examples, the application requires a diverse array of measurements based on sensors for physical, chemical and biological systems. Together, these requirements pose a significant challenge for conventional sensor network methods. We describe the development and applications of a new general purpose method for actuated sensing - Iterative experiment Design for Environmental Applications (IDEA). IDEA introduces a new in-field adaptation of the sensing systems including static and actuated sensors. IDEA addresses the limitations of previous sampling approaches, for example conventional adaptive sampling, by guiding adaptive sampling with an iteratively developed phenomenon model. This paper presents applications of IDEA to: (1) Three-dimensional characterization of contaminant concentration and flow at the confluence of two major rivers; and (2) Characterization of phytoplankton dynamics in a lake system. These applications provide ideal tests by presenting complex structures associated with each phenomenon and enabling a comprehensive evaluation of the general applicability of IDEA methodology. Improved performance using guided adaptive sampling is demonstrated for two existing methodologies, stratified adaptive sampling and hierarchical non-stationary Gaussian Processes. The IDEA experimental results both validate the general applicability of this method and also have advanced the understanding of interrelated physical, chemical and biological processes in these sampled environments.publicIDEA: Iterative experiment Design for Environmental Applicationsarticlelocaloai:escholarship.org:ark:/13030/qt5pt8v7b22011-07-02T20:59:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5pt8v7b2Thomas C. HarmonauthorRichard F. AmbroseauthorRobert M. GilbertauthorJason C. FisherauthorMichael StealeyauthorWilliam J. Kaiserauthor2006-01-01Increasing demands on water supplies, non-point source pollution, and water quality-based ecological concerns all point to the need for observing stream flow perturbations and pollutant discharges at higher resolution than was practical in the past. This work presents a rapidly deployable Networked Infomechanical System (NIMS RD) technology for observing spatiotemporal hydraulic and chemical properties across stream channels.publicHigh Resolution River Hydraulic and Water Quality Characterization Using Rapidly Deployable Networked Infomechanical Systems (NIMS RD)articlelocaloai:escholarship.org:ark:/13030/qt4ts5w2ch2011-07-02T20:59:50Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4ts5w2chThomas SchoellhammerauthorJennifer WongauthorMark HansenauthorMiodrag PotkonjakauthorDeborah Estrinauthor2006-01-01Understanding the dynamics of a microclimate environment is difficult because of the number of factors that lead to changes in the environment. Minimizing the number of sensors needed to accurately characterize the environment results in low deployment and maintenance cost, while maximizing the utility of the data. Optimal sensor placement is difficult because it is dependent upon the properties of the environment, the types of obstacles in the environment, as well as the sensing phenomenon. We have deployed a sensor network in a botanical garden consisting of both static and portable nodes. Each node is equipped with temperature and humidity sensors, and readings were taken once per minute for over a month. Using the data from this deployment we present and evaluate two different approaches to sensor placement. The basis for our deployment approach is spatial-temporal statistical analysis that combines splinebased modeling, principal component analysis, and data partitioning. We prove that sensor network deployment is an NP-complete problem using a transformation from the dominating set problem. We also develop an integer linear programming (ILP) formulation that calculates the provably optimal solution to the network deployment problem.publicSensor Deployment Using Interleaved Experimentation, Modeling, and Optimizationarticlelocaloai:escholarship.org:ark:/13030/qt60k9t66z2011-07-02T20:59:45Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/60k9t66zRichard GuyauthorBen GreensteinauthorJohn HicksauthorRahul KapurauthorNithya RamanathanauthorTom SchoellhammerauthorThanos StathopoulosauthorKaren WeeksauthorKevin ChangauthorLew GirodauthorDeborah Estrinauthor2006-01-01The Extensible Sensing System (ESS) has been in use for several years in a variety of sensor network deployments. It is a key component of a collection of tools that together are a nearly complete, end-to-end, sensor-to-user facility for deploying and managing a sensor network. This paper provides the context and architectural overview of ESS, along with selected deployment details and a series of lessons learned. Lesson areas include connectivity, interactivity, energy vs. robustness, vertical integration, and real-time visibility. The current version of ESS reflects changes from these lessons; further, new tools are in development that complement ESS.publicExperiences with the Extensible Sensing System ESSarticlelocaloai:escholarship.org:ark:/13030/qt91v6t8j22011-07-02T20:59:35Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/91v6t8j2Aman KansalauthorWilliam J KaiserauthorGregory J PottieauthorMani B Srivastavaauthor2005-01-01The information acquisition performance of a sensor network is critical to all applications based on it. This performance depends on factors which cannot be completely known at design or deployment time: sensing medium characteristics and the phenomenon distribution. Simplifying assumptions such as the homogeneous nature of sensing media do not hold in most practical scenarios due to the presence of sensing obstacles. Further, the medium and phenomena may change over time. We propose to use controlled mobility to enhance coverage at run time in an autonomous manner. However, extensive robotic capabilities and supporting services such as precise navigation may be infeasible in large scale sensor networks. We present feasible alternatives for physical reconfiguration using low complexity and low energy actuation. The key contribution of the paper is to show that even small degrees of actuation can lead to a significant coverage advantage. We also compare this approach to conventional means for achieving equivalent coverage by increasing node density without actuation. Further, we discuss the relevant trade-offs which affect the use of mobility in terms of the time required for actuation.publicActuation Techniques for Sensing Uncertainty Reductionarticlelocaloai:escholarship.org:ark:/13030/qt2nj1r0x82011-07-02T20:59:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2nj1r0x8Ben GreensteinauthorAlex PesterevauthorChristopher MarauthorEddie KohlerauthorJack JudyauthorShahin FarshchiauthorDeborah Estrinauthor2007-01-01Embedded systems can already capture data produced at high rates, and embedded CPU and sensor performance are still rapidly improving. Radio technology, however, can not keep pace, and will not in the future due to known physical limits of shared communication channels. This leads to a fundamental gap between the data a sensor network node can collect and the data it can transmit back for analysis. VanGo, our software system for data collection, uses flexible transcoding to narrow this gap. To make effective use of channel bandwidth, data reduction software must run on sensor nodes. However, to calibrate how data reduction software should run, that same software should be capable of running on the back end on real data received from the network. In VanGo, users decide where data processing occurs. To show that transcoding helps, we evaluate two radically different applications: acoustic collection and the measurement of neural activity. Among our findings is that in bandwidth-limited environments, proactive filtering of some of our signal can result in collecting three times the signal energy than we could by removing silent periods alone.publicCollecting High-Rate Data Over Low-Rate Sensor Network Radiosarticlelocaloai:escholarship.org:ark:/13030/qt41b2k7b62011-07-02T20:59:25Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/41b2k7b6Ramesh GovindanauthorEddie KohlerauthorDeborah EstrinauthorFang BianauthorKrishna ChintalapudiauthorOm GnawaliauthorSumit RangwalaauthorRamakrishna GummadiauthorThanos Stathopoulosauthor2005-01-01Future large-scale sensor network deployments will be tiered, with the motes providing dense sensing and a higher tier of 32-bit master nodes with more powerful radios providing increased overall network capacity. In this paper, we describe a functional architecture for wireless sensor networks that leverages this structure to simplify the overall system. Our Tenet architecture has the nice property that the mote-layer software is generic and reusable, and all application functionality resides in masters.publicTenet: An Architecture for Tiered Embedded Networksarticlelocaloai:escholarship.org:ark:/13030/qt7391w3v22011-07-02T20:59:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7391w3v2Deborah Estrinauthor2005-01-01A large class of delay tolerant sensor-net applications require reliable deliver of every data point. The nature of sensor network deployments makes providing reliability a challenge. Harsh environments and unreliable wireless communication can cause long periods of poor to no connectivity. Meanwhile, energy and resource constraints on sensor platforms limit retransmissions and buffer sizes. This paper presents an architecture designed for these challenged networks. The architecture provides packet-level, hop-by-hop reliability for delay-tolerant data using sequential storage for buffering during long queue delays. The concepts discussed in this paper are implemented as services in the Extensible Sensing System, a deployment at the James Reserve as part of the Cold Air Flow Project.publicReliability and Storage in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt8v26b5qh2011-07-02T20:59:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8v26b5qhN. RamanathanauthorL. BalzanoauthorM. BurtauthorD. EstrinauthorT. HarmonauthorC. HarveyauthorJ. JayauthorE. KohlerauthorS. RothenbergauthorM.Srivastavaauthor2006-01-01Rapidly deployable sensor networks are portable, reusable, and can take advantage of a human user in the field attending to the deployment. Unfortunately, even small disruptions or problems in collected data must be addressed quickly, as the overall quantity of data gathered is small relative to longterm deployments. In this paper we describe a procedure for calibration and a system for online fault remediation. Care in the calibration process for ion selective electrodes used for water quality assists interpretation of the data. Scientists will have more confidence in the data obtained from a rapid deployment if in-field users can detect and compensate for problems as they occur. We have designed and implemented a tool for use in the field to detect potential faults and provide actions to remedy or validate the faulty data. In January of 2006 we deployed 48 sensors over a period of 12 days in Bangladesh in order to aid in validating a hypothesis on the mass presence of arsenic in the groundwater. Our system is based on the the approximately 25,000 measurements we collected.publicRapid Deployment with Confidence:Calibration and Fault Detection in Environmental Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt8st0m5wk2011-07-02T20:59:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8st0m5wkThomas SchoellhammerauthorBen GreensteinauthorDeborah Estrinauthor2006-01-01Wireless sensor networks for environmental monitoring promise to be a rich source of ecological, biological, and meteorological data. However, current systems largely return data to a central location for offline analysis, and do not support access by mobile users in the instrumented environment. In many environmental monitoring applications, it is critical to support users in the field so that they can correlate manual observations with the sensor network data, engage in system topology adjustments and calibration tasks, and perform system management. However, it is critical that such mobile users do not interfere with the regular data collection functions of deployed systems. One of the critical systems functions needed to support mobile users of wireless sensor networks is routing. In this paper we iden- tify key mobility usage scenarios and present Hyper, a routing layer that enables efficient and reliable data collection for both static and mobile users.publicHyper: A Routing Protocol To Support Mobile Users of Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt28v8b7c92011-07-02T20:59:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/28v8b7c9N. RamanathanauthorT. SchoellhammerauthorD. EstrinauthorM. HansenauthorT. HarmonauthorE. KohlerauthorM. Srivastavaauthor2006-01-01This paper presents the first systematic design of a robust sensing system suited for the challenges presented by soil environments. We describe three soil deployments we have undertaken: in Bangladesh, and in California at the James Reserve and in the San Joaquin River basin. We discuss our experiences and lessons learned in deploying soil sensors. We present data from each deployment and evaluate our techniques for improving the information yield from these systems. Our most notable results include the following: in-situ calibration techniques to postpone labor-intensive and soil disruptive calibration events developed at the James Reserve; achieving a 91% network yield from a Mica2 wireless sensing system without end-to-end reliability in Bangladesh; and the javelin, a new platform that facilitates the deployment, replacement and in-situ calibration of soil sensors, deployed in the San Joaquin River basin. Our techniques to increase information yield have already led to scientifically promising results, including previously unexpected diurnal cycles in various soil chemistry parameters across several deployments.publicThe Final Frontier: Embedding Networked Sensors in the Soilarticlelocaloai:escholarship.org:ark:/13030/qt9wm343pn2011-07-02T20:58:42Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9wm343pnGong ChenauthorNathan YauauthorMark HansenauthorDeborah Estrinauthor2007-01-01Sensor networks generate a variety of data streams in different temporal and spatial resolutions. The data come as numbers text, images, and audio and are dynamically produced periodically and sporadically. How can we organize hundreds of thousands of such data streams? How can we make it easy for scientists and engineers to publish and share such data streams? In this paper, we present our solution, SensorBase.org. It is a web application that not only provides the user with the functionality of a traditional database management system, but also runs under the notion of a Web 2.0 data experience with a responsive user interface design and RSS data feed techniques. SensorBase.org also aims to be a data search engine to promote exploration. Like a web search engine, the user should be able to search for structures, or rather, “signals”, in the data using simple language queries. We provide a solution to a specific type of signal search problem and describe a search framework derived from the solution. A visualization component is in development to help people understand the data and to enhance the results provided by a data search engine. The development of SensorBase.org allows us, the statisticians, to influence “data practices”. People share data and add documentation within the guidelines of SensorBase.org which supports good experimental design and helps future modeling efforts. Last but not least, SensorBase.org provides a base for data integrity and data quality.publicSharing Sensor Network Dataarticlelocaloai:escholarship.org:ark:/13030/qt7fp998hk2011-07-02T20:48:13Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7fp998hkJ. GoldmanauthorD. EstrinauthorM. HamiltonauthorT. HarmonauthorW. Kaiserauthor2006-01-01Recently, scientists from environmental fields such as ecology, environmental engineering, oceanography, seismology, and hydrological sciences have initiated efforts to design and build networks of field-based measurement systems generically called observatories. Analogous in scope to the community-accessible telescopes common in astronomy, these observatories are distributed across the country and capitalize on cyberinfrastructure advances in measurement systems, networking, data management, and visualization. CENS technology has the potential to enable these observatories. CENS faculty and staff have actively participated developing technology appropriate for two of these efforts: the National Ecological Observatory Network (NEON), a research platform designed to advance understanding of how ecosystems and organisms respond to variations in climate and changes in land use, and CLEANER, a network of environmental facilities for environmental engineering research.publicKNO 1: Facilitating the Adoption of Embedded Networked Sensing by Emerging National Environmental Observatoriesarticlelocaloai:escholarship.org:ark:/13030/qt115559172011-07-02T20:47:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/11555917Thomas HarmonauthorWilliam KaiserauthorAlexanderauthorRat'koauthorJason FisherauthorChris ButlerauthorMichael StealeyauthorSandra Rocio Villamizar Amayaauthor2006-01-01Increasing demands on water supplies, non-point source pollution, and water quality-based ecological concerns all point to the need for observing stream flow perturbations and pollutant discharges at higher resolution than was practical in the past. This poster presents a demonstration of the following multiscale ENS approach to observing water quality changes in a regional river network.publicCON 2: A Multiscale Embedded Networked Sensing Water Quality Observatory Pilot Study at the Merced and San Joaquin Rivers Confluencearticlelocaloai:escholarship.org:ark:/13030/qt4sr1r7n92011-07-02T20:47:27Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4sr1r7n9Nithya RamanathanauthorYeonjeongauthorParkauthorLaura BalzanoauthorJuyoul KimauthorJohn EwartauthorMarci BurtauthorThomas HarmonauthorDeborah EstrinauthorJenny JayauthorEddie KohlerauthorJose SaezauthorSarah RothenbergauthorNaim BusekauthorJohn HicksauthorChe-Chuan WuauthorSteve MargulisauthorMani SrivastavaauthorCharlie Harveyauthor2006-01-01The objective of this work is to develop a modular subsurface environmental sensor node in support of aquatic chemistry observations in soils, sediments and groundwater. The resulting node is called as a soil pylon. Along with describing the pylon architecture, this work presents selected results pertaining to (1) a closed-loop system integrating pylon sensor feedback with process simulation and control algorithms, (2) scale up to large areas using soil geospatial properties, and (3) a protocol for pylon sensor fault filtering. In the former two cases, CENS soil pylons are being tested as a means of providing system feedback at a reclaimed water irrigation research plot in Palmdale, California. Another variation of the pylons was recently field-tested in Bangladesh in an effort to contribute to our understanding of the arsenic contamination problem there. The Palmdale pylons track soil moisture, temperature, and nitrate propagation in unsaturated soils.publicCON 1: Embedded Networked Sensing of Subsurface Water Quality Calibration, Fault Detection and Feedback Controlarticlelocaloai:escholarship.org:ark:/13030/qt8g1600k32011-07-02T20:47:21Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8g1600k3Rodrigo VargasauthorWilliam SwensonauthorMike TaggartauthorMichael F. AllenauthorMichael Hamiltonauthor2006-01-01Human-powered minirhizotrons have been used to estimate root and hyphal turnover rates, but recording and image analysis processes are time consuming. Minirhizotron images and CO2 measurements usually have been taken with the available instruments at time intervals longer than the timescales at which ecological processes happen. We are developing an automated minirhizotron capable to record images at user-defined intervals that will be able to capture short-term ecological changes. Image data alone is not enough to understand ecological processes (e.g. root and hyphal turnover), so coupled with the automated minirhizotron we installed a network of soil sensing instruments. We present variations observed in manual long-term monitoring in a minirhizotron tube and continuous soil CO2 concentration and flux to show a potential application of this technology to identify meaningful temporal scales.publicTER 2: AMARSS: Automated Minirhizotron Coupled With Continuous Monitoring of Soil CO2articlelocaloai:escholarship.org:ark:/13030/qt7zx7n2z02011-07-02T20:46:36Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7zx7n2z0Eric GrahamauthorMichael HamiltonauthorPhil RundelauthorWilliam KaiserauthorMark HansenauthorDeborah EstrinauthorMohammad Rahimiauthor2006-01-01Plant and animal phenology measurements provide an important means of understanding the relationship between periodic phenomena, such as leaf flushes or bird nesting dates, and microenvironmental and climatic conditions. The collection of phenological data, however, can be labor intensive, and thus basic phenological information about many plant and animal species is not known. Imaging technologies at the James Reserve are currently being used to collect high-frequency, multiple-location phenological images together with micrometeorological data. Using simple algorithms for color analysis of images, results from the MossCam project have indicated that rainfalls of even 1 mm can result in significant increases of photosynthesis by the moss Tortula priceps and that leaf area of Rhododendron is positively correlated with green: red pixel ratios. Current work on improving algorithms, extending studies to analyze annual carbon budgets, and correlating micrometeorological data with nesting behavior will allow us to increase our understanding animal population dynamics and the climatic effects on plant distributions and primary productivity.publicTER 1: Imagers as Biological Sensorsarticlelocaloai:escholarship.org:ark:/13030/qt9xc7w41s2011-07-02T20:46:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9xc7w41sBill KaiserauthorMark HansenauthorGaurav Sukhatmeauthorthe MAS Teamauthor2006-01-01publicMAS 0: Multi-scale Actuation and Sensing: An Overviewarticlelocaloai:escholarship.org:ark:/13030/qt7sw7w4k62011-07-02T20:46:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7sw7w4k6Nabil Hajj ChehadeauthorGreg Pottieauthor2006-01-01Natural phenomena are difficult to model because there are many real-world complications. These complications in turn affect the sensor network experimental design which aims to answer a scientific question of interest. For example, a light field is affected by the position of the sun, the height of the tree canopy, and the strength of the wind blowing the leaves, among other things.Instead of using equations which relate all these variables to the field, we can use a statistical model which captures our beliefs of what the field will be like. We can take prior information, which may come from our knowledge or from previous experimental experience, and combine it with uncertanties in unknown quantities using the bayesian statistical framework. We learn the parameters of our models from measured data, and use these models to inform our experimental design.If we use a model for the field which is incorrect to design our sensor network experiements, for example to place the sensors, then our final result will not be what we desired. This project explores ways in which these model choices affect the performance of the learning process.publicUncertainties in Modeling of Natural Phenomena (MAS 4)articlelocaloai:escholarship.org:ark:/13030/qt3t00b3m72011-07-02T20:46:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3t00b3m7C. ButlerauthorA. Rat koauthorYair WishjboomauthorT. BendikovauthorT. HarmonauthorD. KimauthorMichael BendikovauthorJ. Judyauthor2006-01-01Many environmental, agricultural, and ecological water quality problems would be better understood and effectively managed if they could be efficiently and economically observed over time in a spatially distributed manner. Unfortunately, the current selection of commercially available chemical sensors is limited, and those that are available are relatively expensive ($200 to $500 ea.), and are generally not optimally packaged for field deployments. Over the past four years, the CENS Sensor group has directed substantial efforts at creating sensitive, selective nitrate sensors with modest power requirements and that are amenable to micro-fabrication methods which will allow the production of large numbers of small sensors. This poster highlights the results of these efforts with respect to (1) potentiometric and (2) amperometric nitrate microsensors. Prototypes of both types of sensors have been successfully tested in the laboratory, using real environmental samples. The potentiometric sensor has been tested in situ in both soil and river systems.publicSEN 2: Scaleable Nitrate Sensors for Soil and Aquatic Observation Applicationsarticlelocaloai:escholarship.org:ark:/13030/qt2qk152bw2011-07-02T20:46:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2qk152bwJeff BurkeauthorDeborah EstrinauthorRamesh GovindanauthorRichard GuyauthorMark HansenauthorWilliam KaiserauthorEddie KohlerauthorTodd MillsteinauthorJens PalsbergauthorMiodrag PotkonjakauthorMani SrivastavaauthorJohn Villasenorauthor2006-01-01publicSYS 0: CENS Systems Research Overviewarticlelocaloai:escholarship.org:ark:/13030/qt30q628jx2011-07-02T20:46:04Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/30q628jxThanos StathopoulosauthorLewis GirodauthorJohn HeidemanauthorDeborah EstrinauthorKaren Weeksauthor2006-01-01We propose CentRoute a centralized on-demand tree-based routing protocol for resource constrained wireless sensor networks. CentRoute is a unicast routing protocol that utilizes source routing to form paths from a node to the sink and vice-versa. Each node in the network can connect to a single tree at a time which is controlled by a dynamically selected root (or sink). By centralizing routing decisions at the root of the tree, which is not subject to the same resource constraints as the rest of the nodes, CentRoute can avoid routing instabilities and inconsistencies, such as loops. The protocol has constant state requirements on the resource-constrained nodes and as a result can scale to networks of high density. Its on-demand nature results in a low control overhead, as the paths are maintained only when data flows through them. We evaluate the performance of our protocol using simulations as well as an experimental testbed.publicCentralized Routing for Resource-Constrained Wireless Sensor Networks (SYS 5)articlelocaloai:escholarship.org:ark:/13030/qt2h91d57v2011-07-02T20:46:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2h91d57vAmit DhariwalauthorBin ZhangauthorArvind PereiraauthorCarl ObergauthorBeth StaufferauthorStefanie MoorthiauthorDavid CaronauthorGaurav Sukhatmeauthor2006-01-01As part of our research, we have designed and developed sensor-actuated network for marine monitoring. The network consists of ten static buoy nodes and one mobile robotic boat for real-time in-situ measurements and analysis of chemical, physical and biologically pertinent phenomena governing the abundance of micro-organisms at relevant spatio-temporal scales. The goal of the network is to obtain high-resolution information on the spatial and temporal distribution of plankton assemblages in aquatic environments using the in situ presence afforded by the network, and to make possible network-enabled robotic sampling of hydrographic features of interest. This work constitutes advances in (1) real-time observing in aquatic ecosystems and (2) sensor-actuated sampling for biological analysis.publicNetworked Aquatic Microbial Observing System (MAS 1)articlelocaloai:escholarship.org:ark:/13030/qt0m73t2c82011-07-02T20:44:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0m73t2c8Rahul BalaniauthorSimon HanauthorRam Kumar Rengaswamyauthor2006-01-01In-situ reconfiguration of software is indispensable in embedded networked sensing systems. The application includes re-tasking a deployed network, fixing bugs, introducing new features and tuning the system parameters to the operating environment. In this poster, we present a system that supports software reconfiguration in embedded sensor networks at multiple levels. The system architecture is based on an operating system consisting of a fixed tiny static kernel and binary modules that can be dynamically inserted, updated or removed unobtrusively. On top of the operating system is a command interpreter, implemented as a dynamically extensible virtual machine, that can execute high-level scripts written in portable byte code. Any binary module dynamically inserted into the operating systems can register custom extensions in the virtual machine interpreter, thus allowing the high-level scripts executed by the virtual machine to efficiently access services exported by a module, such as tuning module parameters. Together these system mechanisms permit the flexibility of selecting the most appropriate level of reconfiguration. In addition to showing the system architecture, we present a systematic analysis of flexibility versus cost tradeoffs provided by these mechanisms.publicMulti-level Software Reconfiguration for Sensor Networks (SYS 17)articlelocaloai:escholarship.org:ark:/13030/qt4v58r0kp2011-07-02T20:44:21Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4v58r0kpKevin NiauthorGreg Pottieauthor2006-01-01The identification of sensors returning unreliable data is an important task when working with sensor networks. The detection of these sensors while in the field can cue human involvement in repairing problem sensors. This ensures meaningful data is collected throughout the entire length of a sensor deployment. We present a method of selecting non-faulty sensors from a given set of sensors that are expected to behave similarly. We use a Bayesian approach to select a subset of sensors which give the best probability of being correct given the data. From this we can determine whether other sensors' readings fall out of a reasonable range for the sensor set. Using data collected in a test conditions and environment data collected in the forest we verify that our method successfully selects all sensors that are expected to be correct.publicBayesian selection of non faulty sensors (SYS 6)articlelocaloai:escholarship.org:ark:/13030/qt2f03b4qq2011-07-02T20:40:48Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2f03b4qqArnaud BenahmedauthorRobert LamauthorChih-Ming Hoauthor2006-01-01The experimental demonstration of a new sensor based on the properties of surface plasmon propagation through nanostructures is presented. This sensor is a sensitive and versatile device, since it is based on the changes in refractive index on a surface. The integration of the surface plasmon band gap sensor within a censor network would provide a versatile platform to obtain biochemical information with an unprecedented depth and granularity.publicSurface Plasmon Band Gap Sensor A new sensor for robust on-field biosensing (SEN 1)articlelocaloai:escholarship.org:ark:/13030/qt6947w9pp2011-07-02T20:40:42Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6947w9ppMike LiuauthorSiyang ZhengauthorY.C. Taiauthor2006-01-01Lab-on-Chip aquatic microorganism analysis system is a new initiative that aims to expedite research in marine biology using chip-based technology. The miniaturized device reduces the total sample and detection time. Also, the chips can be fabricated in large quantities with minimal cost so many experiments can be run in parallel. Our project is organized into two main research areas. First, we would like to develop a chip to monitor the content of the sea water and assess the concentration of different algae. The chip will take in sea water sample, separate the cells based on size, and a downstream impedance sensor will count the number of cells. The second main area of this project is to make a chip that can culture algae and screen for factors inducing toxin production. The exact causes for Peudo-nitzschia to produce toxins are unclear, and we would like to make a chip that cultures Pseudo-nitzschia under different growing conditions.publicLab-on-a-Chip Aquatic Microorganism Analysis System (SEN 2)articlelocaloai:escholarship.org:ark:/13030/qt0df2j8j72011-07-02T20:40:32Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0df2j8j7Che-Chuan WuauthorSteven A. Margulisauthor2006-01-01Data assimilation (DA) provides an estimation framework to characterize the states of a system by merging information in measurements and physical models. The main purpose of this project is to explore the use of DA methods in designing and maximizing the information content of sensor networks deployed in a complex environmental system. The application is a test bed for wastewater reuse for irrigation in Palmdale, CA. In this study, synthetic experiments with the Ensemble Kalman Filter (EnKF) are performed to estimate soil moisture profiles under three uncertainty scenarios: 1) Initial condition uncertainty; 2) Initial condition and irrigation rate uncertainty; and 3) Initial condition, irrigation rate and time-invariant parameter uncertainty. The estimates from the EnKF with data from embedded sensors are compared with the performance of an open-loop forward modeling simulation and show significant improvements in the estimate of system states under all uncertainty scenarios.publicEmbedded Networked Sensing in Soils: A Stochastic Data Assimilation Approach to Network Design and Real-time State and Parameter Estimation (CON 1)articlelocaloai:escholarship.org:ark:/13030/qt2f03r8722011-07-02T20:39:08Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2f03r872M. KohlerauthorJ. WallaceauthorD. SkolnikauthorR. GovindanauthorO. GnawaliauthorJ. PaekauthorP. DavisauthorI. Stubailoauthor2006-01-01publicDevelopments on the CENS Structural Health Monitoring Front (SEI 2)articlelocaloai:escholarship.org:ark:/13030/qt2jh9b5k72011-07-02T20:39:03Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2jh9b5k7Matthew MayernikauthorAlberto PepeauthorJillian C. WallisauthorChristine L. Borgmanauthor2006-01-01At CENS we are committed to sharing, but how and when that sharing is accomplished is not made explicit. Data sharing practices vary by research group and remain a very localized procedure, typically involving a request made to the research group, who clean and massage the data, and then send the data out in some pre-specified form to the requester. As the volume of CENS data increases and the volume of the requests for these data increases, the existing data sharing practices will not scale well, and data sharing will become a hardship for research groups to accommodate. We need to look towards standards for data sharing at the point where data are available to researchers external to CENS, such as SensorBase. The development and implementation of interoperable standards and protocols, such as Open Archives Initiative protocols, can serve as a data and metadata envelope to encourage collection by other institutions without the need for the existing data sharing exchange to occur. This poster reports on results from our interview study of CENS researchers, specifically we explore the ways in which CENS researchers share data, including within their research group and outside of the research group, and the future needs for data sharing policy and standards.publicCENS Data Sharing Practices (KNO 3)articlelocaloai:escholarship.org:ark:/13030/qt1sh5v3sf2011-07-02T20:38:56Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1sh5v3sfStasa MilojevicauthorChristine L. BorgmanauthorAndrew J. WuauthorWilliam A. SandovalauthorJoe WiseauthorKathy GriffisauthorSara Terheggenauthor2005-01-01publicData Management for CENS: Bridging Multiple Communitiesarticlelocaloai:escholarship.org:ark:/13030/qt8dv5m7z32011-07-02T20:38:51Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8dv5m7z3Melissa CookauthorKathy GriffisauthorAletha HarvenauthorKaren KimauthorKelli MillwoodauthorWilliam SandovalauthorVandana ThadaniauthorJoe WiseauthorDeborah Estrinauthor2005-01-01This poster highlights the progress of CENS Pre-College Education group, including inquiry module development, field testing, and the CENSEI project.publicEDU2: CENS Pre-College Application: Supporting the Educational Pipelinearticlelocaloai:escholarship.org:ark:/13030/qt7q75s5012011-07-02T20:38:45Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7q75s501Qing HeauthorYunan MiaoauthorTerry LeeauthorYu-Chong Taiauthor2005-01-01Here we present HPLC chip based chemical sensing. High Performance Liquid Chromatography (HPLC) is one of the most powerful, versatile, and widely used separation techniques. It allows separation, identification, purification, and/or quantification of the chemical compounds in complex mixtures. By miniaturizing HPLC system onto a chip, significantly lower sample and solvent requirements, higher mass sensitivity, and lower cost can be achieved. Moreover, portable HPLC chips can be used for field tests and/or networked sensing, which is impossible or impractical for conventional desktop HPLC systems. We have developed two integrated HPLC chips. One is demonstrated to perform on-chip sample injection, separation and detection of multiple anions in water (~25ppm). The other is capable of performing high-pressure separation of more complex samples, such as digested proteins. A palm-sized wireless LC system based on the liquid chromatography chips is also being developed.publicSEN2: HPLC Chip Based Chemical Sensingarticlelocaloai:escholarship.org:ark:/13030/qt1h6997k92011-07-02T20:38:39Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1h6997k9Dohyun KimauthorIra GoldbergauthorJack W. Judyauthor2005-01-01A nitrate-sensing system that consists of a micromachined sensing chip, anion-permeable membrane, and integrated microfluidic channels has been designed, fabricated, assembled, and tested. Our microsensor was designed for in-situ monitoring of nitrate concentrations in ground water. Cyclic voltammery of nitrate demonstrates high sensitivity of silver in 0.01 M NaOH electrolyte. Thus, a silver microelectrode was patterned for amperometric nitrate detection. An electrochemically oxidized silver electrode was used as a reference electrode. Microfluidic channels were fabricated as flow paths to the microelectrochemical cell for the eluent (0.01 M NaOH) and ground-water sample. A polyimide insulation layer was deposited to protect lead-wires and electrodes from corrosion. The sensor also incorporates an anion-permeable membrane that is used for selective measurement.publicSEN1: A High-Performance Micromachined Amperometric Nitrate Sensor for Environmental Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt7jh8j3xr2011-07-02T20:37:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7jh8j3xrMaxim BatalinauthorGaurav Sukhatmeauthor2005-01-01Monitoring of environmental phenomena with embedded networked sensing confronts the challenges of both unpredictable variability in the spatial distribution of phenomena, coupled with demands for a high spatial sampling rate in three dimensions. A new approach, Networked Infomechanical System (NIMS), has been introduced to combine autonomous-articulated and static sensor nodes enabling sufficient spatiotemporal sampling density over large transects to meet a general set of environmental mapping demands. This work describes our progress on a critical part of NIMS, the Task Allocation module. We present our algorithm and the two basic greedy Task Allocation policies - based on time of the task arrival (Time policy) and distance from the robot to the task (Distance policy). We present results from NIMS deployed in a forest reserve and from a lab testbed.publicACT3: Multi-Robot Task Allocationarticlelocaloai:escholarship.org:ark:/13030/qt851861542011-07-02T20:37:18Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/85186154Laura BalzanoauthorSaurabh GaneriwalauthorMani Srivastavaauthor2005-01-01Data integrity is vulnerable to faulty and malicious behavior in all sensor network systems. Faulty data is inevitable in low-cost sensor systems, and so it becomes necessary to detect and handle faults and malicious data before they cause problems in an integrated sensor system. This project seeks to present algorithms and infrastructure for high integrity sensor networks by focusing on fault models, detection and resilience techniques, and sensor systems support.publicSIP2: High integrity in Sensor Networks: Models, Techniques, and System Supportarticlelocaloai:escholarship.org:ark:/13030/qt3g8355kv2011-07-02T20:37:14Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3g8355kvKarthik DantuauthorJonathan FriedmanauthorAman KansalauthorDavid LeeauthorRichard PonauthorMohammad RahimiauthorLisa ShirachiauthorIlias TsigkogiannisauthorDeborah EstrinauthorWilliam KaiserauthorMani SrivastavaauthorGaurav Sukhatmeauthor2005-01-01Actuation in sensor networks, in the form of the ability change position and orientation of sensor nodes or their components, has emerged as a critical element in coping with deployment uncertainties and run-time dynamics, and in improving performance and efficiency. To facilitate research on algorithms that manage and exploit actuation and applications that benefit from it, CENS has developed a variety of sensor node platforms with novel actuation capabilities. These platform range from those designed for field deployment such as the NIMS node and the Pacbot data mule) to those designed for lab-scale low-cost experimentation using hardware-in-loop emulation. In this poster we describe three of the lab-scale actuation-capable sensor node platforms that have been developed at the Center.publicACT2: Lab-Scale Actuated Sensing Testbedsarticlelocaloai:escholarship.org:ark:/13030/qt1c93h5st2011-07-02T20:37:07Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1c93h5stAman KansalauthorJames CarwanaauthorWilliam J. KaiserauthorGregory J. PottieauthorMani B. Srivastavaauthor2005-01-01Sensing uncertainty is a key performance metric of interest to any application based on a sensor network. It is thus desirable to sense the phenomenon of interest at the highest possible sensing resolution to achieve the least uncertainty. Given a finite set of sensing resources, it is of interest to determine how to allocate these resources for the best sensing performance. This allocation depends on the distribution of the sensed phenomenon in space and also the characteristics of the medium, such as the presence of obstacles. We propose methods to acquire this environmental information and then move the sensors to improve the sensing performance.publicCoordinated Actuation for Sensing Uncertainty Reductionarticlelocaloai:escholarship.org:ark:/13030/qt4wp0z5p32011-07-02T20:36:50Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4wp0z5p3Gaurav SukhatmeauthorBill Kaiserauthorthe Actuation teamauthor2005-01-01publicACT0: CENS Actuation Research: Overviewarticlelocaloai:escholarship.org:ark:/13030/qt0pt391412011-07-02T20:36:43Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0pt39141Richard GuyauthorMohammad RahimiauthorKaren WeeksauthorVineet AgarwalauthorNaim BusekauthorLewis GirodauthorBen GreensteinauthorSam IrvineauthorRahul KapurauthorMartin LukacauthorAndrew ParkerauthorNithya RamanathanauthorTom SchoellhammerauthorThanos StathopoulosauthorJeff TsengauthorHanbiao WangauthorDeborah Estrinauthor2005-01-01publicSYS7: CENS Systems-Infrastructure Overviewarticlelocaloai:escholarship.org:ark:/13030/qt13w231kr2011-07-02T20:36:38Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/13w231krKrishna ChintalapudiauthorDeborah EstrinauthorOm GnawaliauthorRamesh GovindanauthorEddie KohlerauthorJeong PaekauthorSumit RangwalaauthorThanos Sthathopoulosauthor2005-01-01Over the last five years, sensor network research has seen significant advances in the development of hardware devices and platforms, and in the design of services and infrastructural elements such as routing, localization, and time synchronization. Deployed systems, however, have lagged behind. In this poster, we will describe an alternative architecture, called Tenet, for sensor networks that constrains placement of application-specific functionality on relatively unconstrained nodes. We will then briefly describe our experiences with an early prototype system built on this architecture.publicSYS6: Tenet: An Architecture for Tiered Embedded Networksarticlelocaloai:escholarship.org:ark:/13030/qt67b0x5dt2011-07-02T20:35:06Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/67b0x5dtMichael GlickmanauthorDohyun KimauthorDr. Jack Judyauthor2005-01-01Before the miniature nitrate sensors designed by the CENS Embedded Sensor Project can be integrated into a wireless sensor network, each sensor must first have a sample preparation system that filters the incoming ground water for substances that could damage the sensor or cause faulty results, while still preserving the substance to be measured. Therefore, we are designing a compact, low-power system to provide a continuous stream of segregated acceptable samples to the sensors to enable them to work in remote environments.publicAutomated Sample Preparation for CENS Embedded Sensorsarticlelocaloai:escholarship.org:ark:/13030/qt5f95n0bd2011-07-02T20:35:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5f95n0bdM. KohlerauthorI. StubailoauthorP. Davisauthor2005-01-01Wave propagation effects can be useful in determining the system identification of a building, especially one such as the UCLA Factor building which is so densely instrumented. The density of the measurements makes it possible to observe subtle changes between pairs of floors, to relate the measurements to system properties such as stiffness due to the structural elements, and to measure potential changes in properties such as changes in stiffness due to a column failure. The primary measurements made here are travel times and average velocity after obtaining deconvolved waveforms from displacement time series. The resulting impulse response functions will be used in comparisons with numerical simulations with a model of Factor in finite element calculations.publicObservations of Wave Propagation Effects Through the UCLA Factor Buildingarticlelocaloai:escholarship.org:ark:/13030/qt990264w92011-07-02T20:34:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/990264w9Joon AhnauthorJabed FaruqueauthorJung-Hyun JunauthorShyam KapadiaauthorYongjin KimauthorSundeep PattemauthorSapon TanachaiwiwatauthorMarco ZunigaauthorBhaskar KrishnamachaauthorAhmed Helmyauthor2005-01-01ACQUIRE is a research project at the University of Southern California investigating data centric active querying in wireless sensor networks. The goals of the project are to develop and analyze a novel framework and protocols for scalable querying and resource discovery in next generation wireless sensor networks.publicThe ACQUIRE Projectarticlelocaloai:escholarship.org:ark:/13030/qt90p2k22s2011-07-02T20:34:50Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/90p2k22sLaura BalzanoauthorNithya RamanathanauthorEric GrahamauthorMark HansenauthorMani Srivastavaauthor2005-01-01High Integrity in Sensor Networks studies the effect of compromised data on sensor network data analysis and data fusion algorithms. We are at the start of a study to better understand the compromised data itself so that we can model it in such a way to characterize this affect on analysis. The accelerated life experiment we describe here was instrumented to see how the accuracy of a temperature and humidity sensor changes across mote and sensor systems and across time as the battery dies. We found that the error in the measurements was stable over time, but the bias in the measurements varied greatly across the motes. The experiment gave us more information on the important variables to include in calibration function, so that we can estimate the true measured value from the reported value of the sensor.publicAn Investigation of Sensor Data Integrityarticlelocaloai:escholarship.org:ark:/13030/qt4qt434pp2011-07-02T20:34:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4qt434ppAmit DhariwalauthorBin ZhangauthorEric ShiehauthorBeth StaufferauthorCarl ObergauthorDavid CaronauthorAristides RequichaauthorGaurav Sukhatmeauthor2005-01-01There is a need to provide a platform for better monitoring and sampling in Marine environments. Such a platform should be able to withstand the highly dynamic nature of such an environment as well as cope with its vastness. The platform should be simple and easily scalable. A platform of this type would provide the scientists an invaluable tool in order to further the marine research by monitoring phenomena of biological importance. As part of our research, we are building a fleet of autonomous roboducks (robotic air boats) for in-situ operation (data collection and analysis: using the stargate platform) in marine environments. The platform would support a variety of sensor suites and at the same time be easy to operate. It can operate in both exploration mode and intelligent mode. It can also collaborate (via communication) with other entities (sensor nodes, again using the stargate platform) in the local neighborhood making intelligent decisions. The roboduck fleet in conjunction with the buoy network will serve as a test bed for evaluating algorithms including bacterial navigation for marine sensing and adaptive sampling.publicNetworked Aquatic Sampling Systemarticlelocaloai:escholarship.org:ark:/13030/qt95c2h8th2011-07-02T20:34:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/95c2h8thRoja BandariauthorVictor ChenauthorWillie ChenauthorWendy GwoauthorEric LinauthorKris PorterauthorRachel ScollansauthorMichael StealeyauthorLynn WangauthorEric Yuen. NIMS Graduate Students: Maxim BatalinauthorRobert GilbertauthorJason GordonauthorAman KansalauthorXiangming KongauthorDuo LiuauthorChris LucasauthorRichard PonauthorMohammad RahimiauthorNithya RamanathanauthorLisa ShirachiauthorArun SomasundaraauthorJeffrey TsengauthorAshutosh VermaauthorWinston WuauthorYan Yu. NIMS Faculty: Richard AmbroseauthorDeborah EstrinauthorMichael HamiltonauthorMark HansenauthorTom HarmonauthorJenny JayauthorWilliam J. Kaisauthor2005-01-01Rapidly growing stress on the natural environment has created an urgent demand for new environmental exploration systems that operate remotely and autonomously. As sensor networks are applied to these critical environmental monitoring problems, a series of new requirements have emerged for extensive characterization of dynamic phenomena in three-dimensional environments. The unpredictable presence of obstacles to sensing and the inherent temporal evolution of events create limitations for optimal deployment of sensors in the environment. Networked Infomechanical Systems (NIMS) technology has been developed to introduce precise and sustainable actuation for distributed sensing. NIMS devices are suspended on cable infrastructure to provide a combination of broad range motion combined with accurate localization.publicNetworked Infomechanical Systems-NIMSarticlelocaloai:escholarship.org:ark:/13030/qt4v96k29q2011-07-02T20:34:34Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4v96k29qRobert GilbertauthorVictor ChenauthorWillie ChenauthorGerald KimauthorYeung LamauthorMichael StealeyauthorDr. Richard AmbroseauthorDr. William Kaiserauthor2005-01-01The impacts of anthropogenic inputs on streams in urban watersheds include seasonal algal blooms, high bacteria levels, elevated nutrient concentrations, and altered channel morphology, all of which are commonplace in southern California urban streams. Although it is clear that urbanization effects stream health, the complex mechanisms leading to symptoms such as elevated algal biomass are not well understood. In order to better understand the relationship between urbanization and stream health, the temporal and spatial variation of stream water parameters in urban streams need to be known. Understanding these patterns will help elucidate the driving mechanisms leading to stream degradation and allow for improved management practices. Using various water quality sensors and NIMS technology, the temporal (daily, weekly, and monthly) and spatial (cross sectional and reach scale) variation in Medea Creek in Agoura Hills, CA is being monitored. By analyzing the correlations between these parameters we will be able to determine the driving biotic and abiotic mechanisms leading to the excess algal biomass and nutrient concentrations in Medea Creek.publicNIMS Public Health Applications: Algal Bloomsarticlelocaloai:escholarship.org:ark:/13030/qt6dg7q4zh2011-07-02T20:34:28Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6dg7q4zhBen GreensteinauthorAlex PesterevauthorChristopher MarauthorEddie KohlerauthorJack JudyauthorShahin FarshchiauthorDeborah Estrinauthor2005-01-01Embedded systems can already capture data produced at high rates, and embedded CPU and sensor performance are still rapidly improving. Radio technology, however, cannot keep pace, and will not in the future due to known physical limits of shared communication channels. This leads to a fundamental gap between the data a sensor network node can collect and the data it can transmit back for analysis. VanGo, our software system for data collection, uses flexible transcoding to narrow this gap. To make effective use of channel bandwidth, data reduction software must run on sensor nodes. However, to calibrate how data reduction software should run, that same software should be capable of running on the back end on real data received from the network. In VanGo, users decide where data processing occurs. To show that transcoding helps, we evaluate two radically different applications: acoustic collection and the measurement of neural activity. Among our findings is that in bandwidth-limited environments, proactive filtering of some of our signal can result in collecting three times the signal energy than we could by removing silent periods alone.publicCollecting High-Rate Data Over Low-Rate Sensor Network Radiosarticlelocaloai:escholarship.org:ark:/13030/qt2qr4g4c92011-07-02T20:34:06Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2qr4g4c9Mohammad RahimiauthorShaun AhmadianauthorDavid ZatsauthorJuan GarciaauthorMani SrivastavaauthorDeborah Estrinauthor2005-01-01Recent technological advances in low power CMOS imaging has lead to a new class of imaging devices such as Cyclops. Cyclops is a low power and complexity imaging sensor that mates with conventional sensor network nodes such as Motes.In this demo we present deep vision. An attribute based system that enables orchestrating visual observation through an attribute based system. In our work, visual computations reside on Cyclops sensors and can be addressed as attributes through declarative queries. We present our network architecture and showcase the potential applications and opportunities as well as outstanding challenges. We call our approach deep vision due to the integration of vision with the finest granularity of the sensor network.publicDeep Vision: Experiments in Exploiting Vision in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt57q0g2f72011-07-02T20:34:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/57q0g2f7Sahar Sedighpour ( NESL-UCLA)authorSrdjan Capkun ( IMMauthorTechnical University of Denmark )authorSaurabh GaneriwalauthorMani Srivastava ( NESL-UCLA )author2005-01-01Recently, researchers have proposed a number of ranging and positioning techniques for wireless networks. However, they all studied these techniques in non-adversarial settings. Distance estimation and positioning techniques are, nevertheless, highly vulnerable to attacks from dishonest nodes and malicious attackers. Internal attackers can report false position and distance information in order to cheat on their locations and external attackers can modify the measured positions and distances of wireless nodes. In this work, we demonstrate two attacks on ultrasonic ranging systems: the wormhole attack, by which the attackers reducethe distance measured between two honest nodes, and the pulsedelay attack, by which the attackers enlarge the measured distance. With these attacks, we show that the attackers can arbitrarily modify distances measured with ultrasonic ranging, despite the authentication and integrity protection of the messages used in the ranging protocol. Based on this difference, B estimates its distance to A.publicDistance Enlargement and Reduction Attacks on Ultrasound Rangingarticlelocaloai:escholarship.org:ark:/13030/qt269727tb2011-07-02T20:33:57Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/269727tbJason HsuauthorSadaf ZahediauthorJonathan FriedmanauthorAman KansalauthorVijay RaghunathanauthorMani Srivastavaauthor2005-01-01publicEnabling Long-Lived Sensor Networks Through Solar Energy Harvestingarticlelocaloai:escholarship.org:ark:/13030/qt3g94b0qc2011-07-02T20:33:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3g94b0qcColin RundelauthorEric Grahamauthor2005-01-01As envisioned by the NEON program, sensor networks will commonly be deployed as a tool of ecologists and biologists in the future. For such users it is important to have a simple and easy to use interface that assumes no specific technical knowledge of how the underlying sensor network functions. To this end, we have implemented a suite of simple tools to allow an end-user to interact with data from several test deployments at the James Reserve. Key features of these tools include the monitoring of the overall health of a sensor network through automatic sanity checks and data visualization. Additionally, the end-user is provided low and high level access to historical data through a robust database backend and web based visualization system.publicEnd-user Interface and Backend for Wireless Networksarticlelocaloai:escholarship.org:ark:/13030/qt3rc498k12011-07-02T20:33:47Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3rc498k1Chi-Yuan ShihauthorQing HeauthorCarl ChinauthorYu-Chong Taiauthor2005-01-01We have developed an integrated ion liquid chromatography chip, which is integrated with column, frits/filters, injector and conductivity detector. On-chip separation and detection of anions in water (~25ppm) have been successfully demonstrated. The detection limit is estimated to be 1ppm for the common anions. A much-improved 2nd-genaration chip is currently being developed to do better injection, separation, and detection. A palm-sized wireless LC system based on the LC chip is also actively being developed.publicIon-Liquid Chromatography On-A-Chip For Multiple Ions Sensingarticlelocaloai:escholarship.org:ark:/13030/qt6k57n2152011-07-02T20:33:42Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6k57n215Ramakrishna GummadiauthorNupur KothariauthorRamesh GovindanauthorTodd Millsteinauthor2005-01-01publicKairos: A Macro-Programming Model for Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt0dw2039w2011-07-02T20:33:37Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0dw2039wAlejandro EnriquezauthorJohn HicksauthorKapy KangombeauthorJames Segedyauthor2005-01-01Our goal was to investigate the feasibility of using a wireless sensor network to measure the temporal and spatial variations in microclimates in the Bernard Field Station (a lizard habitat across from the Harvey Mudd Campus). Microclimates are the immediate meteorological conditions experienced by organisms. We did this in a non-intrusive way, basically by distributing remote sensors that would provide habitat monitoring via a wireless network grid. Sensor networks are en emerging technology that allow simple embedded computers with attached sensors to be placed in an environment for remote data gathering. A deployment in the Bernard Field Station can be used by biologists and ecologists to better understand how lizard habitats are affected by local phenomenon including temperature, light sensitivity, and noise. The deployment can act as a testbed for sensor network research including the development of easier to deploy hardware and software elements, improved interfaces to the network, and network protocol development. Our sensor network uses the SOS Operating System (primarily for its inherent ability to support dynamic module loading) running of MicaZ motes.publicLizardnet: Developing and Testing a Non-Invasive Wireless Sensor Network in a Lizard Habitatarticlelocaloai:escholarship.org:ark:/13030/qt880509mc2011-07-02T20:33:12Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/880509mcJessica FengauthorMiodrag Potkonjakauthor2005-01-01We have developed an on-line and in-field error modeling technique, which is a generalization of the calibration problem, that relies on a small number of inaccurate sensors with known error distributions to develop error models for the deployed in-field sensors. We demonstrate the applicability of our transitive error modeling technique and evaluate its performance in various scenarios by conducting experiments using traces of the light intensity measurements recorded by in-field deployed light sensors. In addition, statistical validation and evaluation methods such as resubsitution are used in order to establish the interval of confidence.publicTransitive Error Characterization for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt3gb072q52011-07-02T20:32:56Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3gb072q5Sahar KashefauthorJia Ning (Jane) QuauthorKaren Weeksauthor2005-01-012005 CENS Summer Intern:Emstar, a software infrastructure developed by CENS, is used to monitor wireless sensor networks (among other things). However, using EmStar requires a level of programming and Linux skill that the general scientific community should not be required to possess. Our objective was to create an easy to use internet interface, named Cohesion, so that anyone with basic web knowledge can take advantage of the capabilities of EmStar. Over the duration of the internship, we have developed the layout of the homepage and implemented several of the links from the homepage. Currently, users can send queries to a mote network and view network status information.publicCohesion Web Interface to EmStararticlelocaloai:escholarship.org:ark:/13030/qt1zj2j21d2011-07-02T20:32:29Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1zj2j21dmahanaz, tabassumauthorDevarakonda, Swathiauthor2008-02-01Wireless sensor networks are new type of emerging networks with bunch of applications in all fields due to their low cost and low power scheme. As these networks follow open wireless communication, they undergo dynamic node problems and fault node detection due to malicious node activities. In this paper we overcome these problems with the help of algorithms that will provide uninterrupted communication and also save node’s energy and time.function. It is therefore critical for the base station to find out the reason for the node failure. To distinguish these cases, the base station needs to trace all dead nodes.publicSensorsdynamic node eventsfault toleranceDynamic Node and Fault Tolerance in WSNarticlelocaloai:escholarship.org:ark:/13030/qt71x8s5vr2011-07-02T20:31:21Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/71x8s5vrLaura DionisioauthorMohammad Rahimiauthor2005-01-012005 CENS Summer Intern:The concept behind the Water level Control System is to program a mote to the extent that it can not only read and send data, but can also interpret and use the data as needed. Normally when a mote collects and sends data, it is unreadable and contains other information such as the header of the packet, its address, it’�¡�Çs length, etc. The Water level Control System can interpret the data collected, display readable data onto the computer screen and use the data to determine the status of the water level and pump. It is a simple model system that represents a water supply and demand situation. For example, if there was a water supply at the bottom of a mountain and water was needed at the top of the mountain, a wireless mote at the top of the mountain can send a packet to another wireless mote at the bottom of a mountain to indicate that water is needed. The Water Level Control System works in the same way except at a much smaller scale, however, it was designed such that it can also apply on a larger scale.publicA Wireless Water Level Control Systemarticlelocaloai:escholarship.org:ark:/13030/qt1hq4921q2011-07-02T20:28:20Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1hq4921qH. WangauthorJ. ElsonauthorL. GirodauthorD. EstrinauthorK. YaoauthorL. Vanderbergeauthor2003-01-01publicTarget Classification and Localization in Habitat Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt2dr3t4bm2011-07-02T20:26:37Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2dr3t4bmArvind Menezes PereiraauthorGabriel SibleyauthorGaurav SukhatmeauthorAmit DhariwalauthorBin ZhangauthorCarl ObergauthorBeth StaufferauthorStefanie MoorthiauthorDavid Caronauthor2006-01-01This poster describes ongoing work to use stereo vision for robotic boat navigation. Stereo is low-power which makes it attractive for embedded applications. Stereo is also a challenge due to the complexity of the application domain, the myriad effects of varying illumination, and inherent bias and calibration errors. We describe a preliminary design for our system that will enable an autonomous surface vehicle to navigate using a waypoint following mode through the fusion of measurements from stereo vision, inertial sensors and GPS. We describe initial results obtained from lab tests and field experiments at Lake Fulmor.publicStereo Vision Aided Navigation for Robotic Boats (MAS 10)articlelocaloai:escholarship.org:ark:/13030/qt7s0013nx2011-07-02T20:26:32Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7s0013nxOmprakash GnawaliauthorBen GreensteinauthorKi-Young JangauthorAugust JokiauthorPaek, JeongyeupauthorMarcos VieiraauthorDeborah EstrinauthorRamesh GovindanauthorEddie Kohlerauthor2006-01-01Most sensor network research and software design has been guided by an architectural principle that permits multi-node data fusion on small-form-factor, resource-poor nodes, or motes. We argue that this principle leads to fragile and unmanageable systems and explore an alternative. The Tenet architecture is motivated by the observation that future largescale sensor network deployments will be tiered, consisting of motes in the lower tier and masters, relatively unconstrained 32-bit platform nodes, in the upper tier. Masters provide increased network capacity. Tenet constrains multimode fusion to the master tier while allowing motes to process locally-generated sensor data. This simplifies application development and allows mote-tier software to be reused. Applications running on master task motes by composing task descriptions from a novel tasking library.publicTenet: An Architecture for Tiered Embedded Networks (SYS 8)articlelocaloai:escholarship.org:ark:/13030/qt7bx706ft2011-07-02T20:26:27Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7bx706ftMartin LukacauthorVinayak NaikauthorAllen HuskerauthorIgor StubailoauthorPaul DavisauthorDeborah Estrinauthor2006-01-01We will provide TDMA-based state-synchronization service that will provide low latency and high reliability. Our TDMA service will be built on top of the existing MAC found in the radios for Aensbox. We will provide deployment tools, which will enable the deployer to gauge the quality of the deployed network. Our tools will use above mentioned efficient and reliable state-synchronization service and will work without assuming any end-to-end routing service. We will provide system software for Aensbox, which a multi-processor and multi-radio platform. The desired system software must utilize dual processor and radio depending upon the energy consumption of the operation, e.g. a continuous battery monitoring operation can be delegated to a low power processor (MSP), while analysis of a large data-set will be done by high power processor (XScale). Although, comprehensive evaluation of the entire system can be done only at the real scale, it is necessary to gain confidence at early stages of development where real deployment is not possible.publicGeoNet: A Platform for Rapid Ditributed Geophysical Sensing (SYS 12)articlelocaloai:escholarship.org:ark:/13030/qt9c98s36g2011-07-02T20:26:06Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9c98s36gYan YuauthorMohammad RahimiauthorLisa ShirachiauthorSteve LiuauthorRichard PonauthorNithya RamanathanauthorLewis GirodauthorWilliam KaiserauthorDeborah Estrinauthor2004-01-01The new Networked Infomechanical Systems (NIMS) architecture combines both fixed and mobile sensor nodes to achieve a spatiotemporal environment coverage that is dramatically advanced over that of either system alone. NIMS is applied to challenging environmental monitoring applications regarding primary problems in science and public health. The NIMS system includes a horizontally mobile node, a vertically mobile node, and many environmental sensors, actuators, and wireless network communication among these components. This presents a particularly capable monitoring system, but with associated high complexity that must be managed and presented properly to the system designer. This poster presents how EmStar-based architecture helps to achieve the critical requirements for the embedded system software architecture: (1) Support for autonomous and robust system operation in an unattended field environment; (2) Seamless transition from emulation, through laboratory-scale NIMS systems, to the field deployment; (3) Support for control and management of many complex device drivers that appear in NIMS electromechanical systems.publicSoftware Architecture for Environmental Sensing and Actuation in NIMSarticlelocaloai:escholarship.org:ark:/13030/qt57m9v9p12011-07-02T20:26:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/57m9v9p1Yen-Cheng KuanauthorAndres SavvidesauthorMani Srivastavaauthor2003-01-01None provided.publicAd-Hoc Localization Infrastructurearticlelocaloai:escholarship.org:ark:/13030/qt49b1n75d2011-07-02T20:25:16Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/49b1n75dEric YuenauthorMichael StealeyauthorWillie ChenauthorYueng LamauthorSteve LiuauthorChris LucasauthorWilliam Kaiserauthor2004-01-01Abstract: Metrology presents NIMS with a way to monitor specific objects in the environment such as plants and leaves. The addition of sensor fusion allows NIMS to analyze objects from multiple perspectives and provide detailed information on objects in the environment.publicNIMS Metrologyarticlelocaloai:escholarship.org:ark:/13030/qt34t715w22011-07-02T20:24:29Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/34t715w2Aman KansalauthorWilliam KaiserauthorGreg PottieauthorMani Srivastavaauthor2004-01-01The performance of a sensor network may be best judged by the quality of application specific information return. The actual sensing performance of a deployed sensor network depends on several factors which cannot be accounted at design time, such as environmental obstacles to sensing. We propose the use of mobility to overcome the effect of unpredictable environmental influence and to adapt to run time dynamics. Now, mobility with its dependencies such as precise localization and navigation is expensive in terms of hardware resources and energy constraints, and may not be feasible in compact, densely deployed and widespread sensor nodes. We present a method based on low complexity and low energy actuation primitives which are feasible for implementation in sensor networks. We prove how these primitives improve the detection capabilities with theoretical analysis, extensive simulations and real world experiments.publicActuation Methods for Enhanced Coveragearticlelocaloai:escholarship.org:ark:/13030/qt6pv5x5xf2011-07-02T20:24:22Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6pv5x5xfMohammad RahimiauthorMark HansenauthorWilliam KaiserauthorGaurav SukhatmeauthorSteve LiuauthorDeborah Estrinauthor2004-01-01Monitoring of environmental phenomena with embedded networked sensing confronts the challenges of both unpredictable variability in the spatial distribution of phenomena, coupled with demands for a high spatial sampling rate in three dimensions. For example, low distortion mapping of critical solar radiation properties in forest environments may require two-dimensional spatial sampling rates of greater than 10 samples/m2 over transects exceeding 1000 m2. Clearly, adequate sampling coverage of such a transect requires an impractically large number of sampling locations. This work describes a new approach where the deployment of an adaptive sampling algorithm on a mobile sensor node improves the performance of spatiotemporal sampling density to better cope with a set of environmental mapping demands. Here the robot actively builds a statistical model of the environment and picks samples selectively to increase the performance of such modeling. In addition we will present our active modeling simulation that has been implemented in R statistical computing language and can potentially run on the robot in real time.publicFidelity Driven Sampling in Environmental Sensingarticlelocaloai:escholarship.org:ark:/13030/qt55k6416f2011-07-02T20:24:12Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/55k6416fJ. E. HauxauthorT.C. HarmonauthorJ. SaezauthorJ. KimauthorY. ParkauthorN. D. BusekauthorT. SchoellhammerauthorD. Estrinauthor2004-01-01publicEstablishing a Multi-Spatial Wireless Sensor Network to Monitor Nitrate Concentrations in Soil Moisturearticlelocaloai:escholarship.org:ark:/13030/qt6xk216kv2011-07-02T20:22:18Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6xk216kvP. CorkeauthorS. HrabarauthorR. PetersonauthorD. RusauthorS. SaripalliauthorG. Sukhatmeauthor2004-01-01publicAutonomous Deployment and Repair of a Sensor Network Using an Unmanned Aerial Vehiclearticlelocaloai:escholarship.org:ark:/13030/qt0zw6q9jf2011-07-02T20:20:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0zw6q9jfA. KansalauthorD. PotterauthorMB Srivastavaauthor2004-01-01publicPerformance Aware Tasking for Environmentally Powered Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt0x1395kh2011-07-02T20:13:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0x1395khJason MeltzerauthorStefano Soattoauthor2003-01-01We present a method for inferring the location of a robot relative to a three-dimensional map of its environment. The map, created off-line, consists of image patches, their locations in space, and their associated normal vectors. Observational data consist of one or many images taken from the robot’¡Çs current viewpoint (a point and orientation in space). We develop a framework for matching images of a scene (observations) to a map and show how this can be applied to the task of robot localization. Localization is posed as an optimization problem, where the observed data and the map are aligned to produce an estimate of the current pose of the robot. We provide a formalization of our model and demonstrate experimental results in unstructured environments.publicVision Based Navigationarticlelocaloai:escholarship.org:ark:/13030/qt37c6q31b2011-07-02T20:11:56Z am 3u Center for Embedded Network SensingVol. 44, no. 2 (Jan. 2006) 181-195eScholarship, University of Californiahttps://escholarship.org/uc/item/37c6q31bSarah N. DeonarineauthorGobler, Christopher J.authorLonsdale, Darcy J.authorCaron, David A.author2006-01-01Harmful brown tides caused by the pelagophyte Aureococcus anophagefferens have occurred in mid-Atlantic estuaries for 2 decades. Low grazing rates by microzooplankton have been implicated as a possible cause of these events, but no study to date has concurrently quantified zooplankton population densities and zooplankton grazing rates of A. anophagefferens cells. We conducted field studies from 2002 to 2004 to quantify grazing on the brown tide alga A. anophagefferens by meso-, micro-, and nanozooplankton, while concurrently establishing the composition of the plankton community. Research sites included an estuary that experienced an intense brown tide (Chincoteague Bay, Maryland [MD]; 2004: 2 × 10⁶ cells ml⁻¹) and one that experienced sporadic blooms (Quantuck Bay, New York [NY]; 2002: 8 × 10⁵ cells ml⁻¹; 2003 and 2004: × 10⁴ cells ml⁻¹). The MD site was dominated by small autotrophs (µm), such as A. anophagefferens and other picoeukaryotes, and small heterotrophs, such as Paulinella ovalis, while the NY site hosted a range of large and small autotrophs and zooplankton. Experiments indicated that small zooplankton (3 to 5 µm) were consumers of A. anophagefferens at bloom and non-bloom locations. However, dilution experiments documented active grazing on most picoplankton except A. anophagefferens in MD, while grazing rates on the brown tide alga in NY were comparable to grazing rates on the total phytoplankton community and other picoplankton. Experimental enrichment of estuarine waters with mesozooplankton indicated a preferential avoidance of A. anophagefferens by grazers during intense blooms, but active consumption during non-bloom conditions. Differences in the effect of grazing between sites suggest that zooplankton may be controlling brown tides in NY, but allowing blooms to form due to low grazing pressure in MD. These findings further suggest that the zooplankton community in NY has changed from one which formerly avoided the consumption of A. anophagefferens to one which currently contributes to top-down control of brown tides.publicAquaticHarmful algal bloomsBrown tideAureococcus anophagefferensZooplanktonGrazingTrophic cascadePaulinella ovalisSynechococcus sp.Role of Zooplankton in the Onset and Demise of Harmful Brown Tide Blooms (Aureococcus anophagefferens) in US Mid-Atlantic Estuariesarticlelocaloai:escholarship.org:ark:/13030/qt44n870k02011-07-02T20:09:49Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/44n870k0Husker, AllenauthorDavis, Paulauthor2006-12-11The position of the subducting Cocos Plate beneath Mexico is unknown from the Trans-Mexican Volcanic Belt (TMVB) northward. Geochemical analysis suggests that there may be a slab tear causing mafic volcanism along the northern edge of the (TMVB). An array of 100 seismometers at 5 km spacing is currently installed in Mexico by the MesoAmerican Seismic Experiment (MASE) in conjunction with the Center for Embedded Networked Sensing (CENS) at UCLA, the Universidad Nacional Autonoma de Mexico (UNAM), and the California Institute of Technology (CIS). The data from this array is used to develop P and S wave tomographies to locate the slab. Beneath the MASE line the Cocos plate dips from the trench to a ~ 50 km depth. It is almost subhorizontal between 110 km to 275 km from the trench at a ~50 km depth. Then it continues to dip at a near constant angle.publicSeismic7240Subduction zones1207121912407270Tomography69828180Seismic Tomography of the Cocos Platearticlelocaloai:escholarship.org:ark:/13030/qt5vg6h5n02011-07-02T20:09:37Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5vg6h5n0Lee, Dong-UauthorKim, HyungjinauthorTu, StevenauthorRahimi, MohammadauthorEstrin, DauthorVillasenor, Johnauthor2007-01-01Energy-efficient image communication is one of the most important goals for a large class of current and future sensor network applications. This paper presents a quantitative comparison between the energy costs associated with 1) direct transmission of uncompressed images and 2) sensor platform-based JPEG compression followed by transmission of the compressed image data. JPEG compression computations are mapped onto various resource-constrained sensor platforms using a design environment that allows computation using the minimum integer and fractional bit-widths needed in view of other approximations inherent in the compression process and choice of image quality parameters. Detailed experimental results examining the tradeoffs in processor resources, processing/transmission time, bandwidth utilization, image quality, and overall energy consumption are presented.publicMultiscaled Actuated SensingEnergy-Optimized Image Communication on Resource-Constrained Sensor Platformsarticlelocaloai:escholarship.org:ark:/13030/qt0x20w1b82011-07-02T20:08:55Z am 3u Center for Embedded Network SensingVol. 24, no. 2 (Mar. 2007) 205-215eScholarship, University of Californiahttps://escholarship.org/uc/item/0x20w1b8Sukhatme, GauravauthorDhariwal, AmitauthorZhang, BinauthorOberg, CarlauthorStauffer, BethauthorCaron, David A.author2007-03-01This paper describes the design, development, and initial application of a sensor-actuated network for sensing and sampling microbial communities in aquatic ecosystems. The network consists of ten stationary buoys and one mobile robotic boat for real-time, in situ measurements and analysis of chemical and physical factors governing the abundance and dynamics of microorganisms at biologically relevant spatiotemporal scales. The goal of the network is to obtain high-resolution information on the spatial and temporal distributions of plankton assemblages and concomitant environmental parameters in aquatic environments using the in situ presence afforded by the network and to make possible network-enabled robotic sampling of hydrographic features of interest. This work constitutes advances in (1) real-time observing in aquatic ecosystems and (2) sensor actuated sampling for biological analysis.publicAquaticsensor-actuator networkaquatic microbial observing systemrobotic sensor networkplankton dynamicsThe Design and Development of a Wireless Robotic Networked Aquatic Microbial Observing Systemarticlelocaloai:escholarship.org:ark:/13030/qt4x6723n22011-07-02T20:08:43Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4x6723n2Li, XinauthorKim, Young JinauthorGovindan, RameshauthorHong, Weiauthor2003-01-01In many sensor networks, data or events are named by attributes. Many of these attributes have scalar values, so one natural way to query events of interest is to use a multi-dimensional range query. An example is: "List all events whose temperature lies between 50° and 60°, and whose light levels lie between 10 and 15." Such queries are useful for correlating events occurring within the network.In this paper, we describe the design of a distributed index that scalably supports multi-dimensional range queries. Our distributed index for multi-dimensional data (or DIM) uses a novel geographic embedding of a classical index data structure, and is built upon the GPSR geographic routing algorithm. Our analysis reveals that, under reasonable assumptions about query distributions, DIMs scale quite well with network size (both insertion and query costs scale as O(√N)). In detailed simulations, we show that in practice, the insertion and query costs of other alternatives are sometimes an order of magnitude more than the costs of DIMs, even for moderately sized network. Finally, experiments on a small scale testbed validate the feasibility of DIMs.publicSensorsDIMMulti-dimensional Range QueriesMulti-dimensional Range Queries in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt4n1678dh2011-07-02T20:05:35Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4n1678dhMichael AllenauthorLewis GirodauthorDeborah Estrinauthor2007-01-01publicAcoustic Laptops as a research enablerarticlelocaloai:escholarship.org:ark:/13030/qt1s30z37r2011-07-02T20:04:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1s30z37rFred StannauthorJohn Heidemannauthor2003-01-01publicRMST: Reliable Data Transport in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt7vc0s6mp2011-07-02T20:04:20Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7vc0s6mpLewis GirodauthorAndreas AliauthorMani SrivastavaauthorKung Yaoauthor2006-01-01We assess the use of an acoustic ranging system for vehicle safety applications in GPS-denied areas. The system coordinates acoustic vehicle tracking via RF signaling and informs the vehicle of its position relative to potential hazards. To accurately track the position and orientation and be robust against interferer, we use a distinct pseudo-random sequence for each emitter. The Doppler shift due to the movement of the vehicle, degrades the autocorrelation of the ranging sequence, and is compensated via a velocity search algorithm. The testing platform consists of a microphone array suspended over the roadways with receivers and a pair of speakers on the vehicle's bumper acting as the acoustic emitters.publicCooperative Acoustic Vehicle Localization (SYS 1)articlelocaloai:escholarship.org:ark:/13030/qt5px4k90d2011-07-02T20:03:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5px4k90dKaren KimauthorChristine BorgmanauthorMelissa CookauthorKathy GriffisauthorRichard GuyauthorAletha HarvenauthorKelli MillwoodauthorWilliam SandovalauthorLinda SaxauthorVandana ThadaniauthorWesley UeharaauthorJoe WiseauthorDeborah Estrinauthor2005-01-01publicCENS Education Overviewarticlelocaloai:escholarship.org:ark:/13030/qt9gj865qn2011-07-02T20:03:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9gj865qnK ChangauthorN RamanathanauthorD EstrinauthorJ Palsberg.author2005-01-01Understanding how a sensor network system works requires running the system, extracting log files, and manually interpreting system metrics. When interpreting system metrics, we often try to correlate behavior over multiple modalities. For example, if a node is exhibiting strange behaviors, the cause may be due to weak battery, geographically bad placement, collision, interference, sensor failure, algorithmic faults, or a combination of the above. This approach of interpreting metrics is adequate for closed systems such as the ones run in simulations, with limited duration. However, for complex sensor network systems that have already been deployed for weeks or even months in the fields, this approach is difficult, laborious, and error-prone. Thus, a suite of tools to help analyze complex sensor network system is desirable. We have implemented Deployment Analysis System (DAS), a centralized data mining suite designed to better understand sensor networks. It supports visualization and deployment-related queries that allow the user to inspect historical system metrics, environmental data, geographical placements, and system status.publicDAS-- Deployment Analysis Systemarticlelocaloai:escholarship.org:ark:/13030/qt3r8244j92011-07-02T20:03:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3r8244j9Chi-Yuan ShihauthorQing HeauthorJun XieauthorJason ShihauthorYu-Chong Taiauthor2005-01-01It is desirable that in analytical microfluidic systems such as chip-based liquid chromatography that fluidic channel structure is robust enough so to avoid channel fracture at high pressure operation. In addition, the system fluidic dead volume should be minimized so to enhance analysis quality or shorten the analysis time. We demonstrate here using parylene thin film technology to fabricate channel configurations which provide pressure capacity above 1000 psi. Also, practical solutions for chip packaging and fluidic coupling to off-chip world that guarantee leak-free interface and minimal system dead volume are provided.publicParylene Microfluidic Channel and Plumbing Technologyarticlelocaloai:escholarship.org:ark:/13030/qt4hh6d1cr2011-07-02T20:03:36Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4hh6d1crCharles E. TaylorauthorEdward P. StablerauthorMartin CodyauthorKung YaoauthorEdgar E. VallejoauthorYuan YaoauthorAlex KirschelauthorYing LinauthorTravis C. Collierauthor2005-01-01Working with various groups within CENS, we are developing, testing, and will be soon using acoustic sensor arrays to identify, track, and study the social interactions of various bird species. There has been good technical progress towards this goal, especially in the localization and recognition areas. We are currently collecting data and testing prototype systems at three sites, the James Reserve and the Hastings Reserve in California, and the Montes Azules Biopshere Reserve in Chiapas Mexico.publicSensor Arrays for Acoustic Monitoring of Bird Behavior , Diversityarticlelocaloai:escholarship.org:ark:/13030/qt113900np2011-07-02T20:03:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/113900npNithya RamanathanauthorMarci BurtauthorGenevieve FernandezauthorThomas HarmonauthorJennifer JayauthorCharles HarveyauthorRebecca NuemannauthorDeborah Estrinauthor2005-01-01Arsenic in groundwater has lead to a massive poisoning in Bangladesh. Tens of millions of people are currently drinking dangerously high levels of naturally occurring arsenic in groundwater, resulting in adverse health effects. However, we lack a full understanding of the factors controlling arsenic (a naturally occurring element) mobilization to groundwater. A current working hypothesis is that influx of dissolved arsenic to groundwater is greatly enhanced where rice cultivation provides the primary source of aquifer recharge because anoxic irrigation-return flow mobilizes arsenic (As) as it passes through an As-enriched iron oxide band in the sediment. We plan to deploy a wireless sensor network to monitor oxidation-reduction potential (ORP), moisture, soil temperature, calcium, ammonium, pH, oxidation, and nitrate at three depths in pylons located at three different locations.publicProgress toward deployment of a wireless sensor network to understand arsenic mobilization in a Bangladeshi aquiferarticlelocaloai:escholarship.org:ark:/13030/qt6009c7vm2011-07-02T20:03:25Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6009c7vmKathy GriffisauthorJoe Wiseauthor2005-01-01The K-12 education group is developing tools that extend and integrate existing ENS technology into practical use for scientists by engaging the general public with our interactive data classification tool (iDCT).+publicThe Interactive Data Classification Tool (iDCT)articlelocaloai:escholarship.org:ark:/13030/qt2wj9v34m2011-07-02T20:03:20Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2wj9v34mJ.Z. StafsuddauthorS. AsgariauthorC.E. ChenauthorA. AliauthorR. E. HudsonauthorF. LorenzelliauthorK. YaoauthorE. Tacirogluauthor2005-01-01In this poster, we consider the analysis, implementation, and application of wideband sources using both seismic and acoustic sensors. We use the AML algorithm to perform acoustic DOA. For non-uniform noise spectra, whitening filtering was applied to the received acoustic signals before the AML operation. For short-range seismic DOA applications, one method was based on eigen-decomposition of the covariance matrix and a second method was based on surface wave analysis. Experimental estimation of the DOAs and resulting localizations of a source generated by striking a heavy metal plateby a hammer on the ground using the acoustic and seismic signals individually and jointly are reported.publicLocalization based on acoustic and seismic array processingarticlelocaloai:escholarship.org:ark:/13030/qt1tk2p8zr2011-07-02T20:03:16Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1tk2p8zrBrian R. ZuttaauthorEric A. GrahamauthorPhilip W. Rundelauthor2005-01-01A wireless network of sensors was used to characterize a cold-air drainage event in the canyon surrounding the James Reserve. The flow of cold air at night and the first hours of sunrise have major ecological consequences by limiting the vegetation types to those tolerant of freeze and thaw cycles. A network of wireless sensors provides the opportunity to track this event in real time and fully characterize the cold air flow down the canyon, which may last 1.5 hours, and the pooling of cold air in low lying areas. By adjusting the spatial extent of the wireless sensors and the time interval between data capture, we can optimize the spatial and temporal extent of a sensor network and its ability to describe multiple cold-air drainage events.publicModeling a cold-air drainage event with a wireless sensor networkarticlelocaloai:escholarship.org:ark:/13030/qt7g7940x92011-07-02T20:03:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7g7940x9Thanos StathopoulosauthorLewis GirodauthorJohn HeidemannauthorDeborah Estrinauthor2005-01-01Herding, a new system architecture for large scale, heterogeneous sensor networks. Mote herding uses a mix of many 8 bit sensor nodes (motes) and fewer but more powerful 32-bit sensor nodes (microservers). Mote herding groups motes into flocks that are connected via a multihop network to a microserver acting as a shepherd. Shepherds exploit their greater communications and compute power to form an overlay network, with many flocks joining to form a herd. By keeping each flock small and utilizing several shepherds, the herd can support many nodes with better latency, reliability, and energy efficiency than homogeneous architectures. Using the Mote Herding abstractions, we have implemented a set of services that run across both platforms, namely a mote routing service, a data reliability service and a resource discovery service that is based on three subservices.publicMote Herding for Tiered Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt9b1872k22011-07-02T20:02:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9b1872k2Young Jin KimauthorRamesh GovindanauthorBrad KarpauthorScott Shenkerauthor2005-01-01Geographic routing algorithms are attractive for wireless ad hoc networks because they have been shown to scale better than other alternatives they require per-node state independent of network size, dependent only on network density. More recently, geographic routing algorithms have been proposed for use as a routing primitive for static sensor networks, as building blocks for data storage and flexible query processing in sensor networks, and even as a fallback routing mechanism for reduced state routing in the Internet.publicCLDP Robust Planarization for Geographic Face Routingarticlelocaloai:escholarship.org:ark:/13030/qt0mt880qr2011-07-02T20:02:13Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0mt880qrAthanassios BoulisauthorMani Srivastavaauthor2004-01-01publicNode-level Energy Management for Sensor Networks in the Presence of Multiple Applicationsarticlelocaloai:escholarship.org:ark:/13030/qt2sm2502f2011-07-02T20:01:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2sm2502fVijay RaghunathanauthorMani SrivastavaauthorTrevor PeringauthorRoy Wantauthor2004-01-01This poster presents techniques for energy efficient operation of the Stargate wireless platform. In addition to conventional power management techniques such as dynamic voltage and scaling and processor shutdown, the Stargate features several mechanisms for energy efficient operation of the communication subsystem, such as support for hierarchical radios, Bluetooth based remote wakeup, mote based wakeup, etc. Finally, design optimizations including the use of power gating, and provision for battery-state aware operation are also described.publicStargate: Energy Management Techniquesarticlelocaloai:escholarship.org:ark:/13030/qt09q9d0582011-07-02T20:01:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/09q9d058M. ContrerasauthorG. FarrarauthorS. Taylor LangeauthorD. SkolnikauthorE. YuauthorY. LeiauthorJ. Wallaceauthor2004-01-01System identification of a scale structure in the laboratory preceded full scale studies of the Four Seasons office building (Sherman Oaks, CA) under forced vibrations and the Louis Factor building (UCLA) under earthquake and ambient vibrations. An advanced system identification algorithm, N4SID (numerical subspace state space system identification), is employed. The spurious modes generated due to sensor noise and measured errors are distinguished from the physical ones and disregarded through the use of ’¡Èstability diagrams’¡É. A finite element computer program is used to analyze each structure studied and analytical results are compared to experimental results.publicSystem Identification of Structures in the Laboratory and in the Fieldarticlelocaloai:escholarship.org:ark:/13030/qt70q4t2h42011-07-02T20:00:48Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/70q4t2h4Bin ZhangauthorDavid CaronauthorObergauthorAri RequichaauthorBeth StaufferauthorGaurav Sukhatmeauthor2003-01-01The goal of Adaptive Sampling is to achieve relatively high spatial resolution with relatively few sensors/robots. With the abilities of moving and sensing, the sensors/robots are able to estimate where the important areas are, and then accumulate there. In this way, the environment can be sensed with different resolutions in different places but with emphasis on the interesting place.publicAdaptive Sampling for Marine Microorganism Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt8rv785zx2011-07-02T20:00:13Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8rv785zxEric OsterweilauthorMohan MysoreauthorMohamad RahimiauthorAndrew Wuauthor2003-01-01The ESS is designed as a suite of components that enable and facilitate sensor networks, their deployment, management, and usage. In meeting its charter, the ESS spans a comprehensive set of platforms and operates in a diverse set of environments. It is, therefore, based on a tiered architecture comprised of; motes (mica2, tos, chipcon, sensor interface board), microservers (strongarm/xscale, linux, motenic, 802.11), commodity platforms (x86, linux, 802.11) platforms, and enterprise platforms (such as solaris and oracle)...publicThe Extensible Sensing Systemarticlelocaloai:escholarship.org:ark:/13030/qt2sb5k2562011-07-02T19:59:42Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2sb5k256Dantu, KarthikauthorSukhatme, Gauravauthor2006-05-31Tiered sensor network architectures are gaining currency. In contrast with flat networks of impoverished nodes (the hitherto common assumption in sensor networking), such systems offer the promise of migrating computational load from sensing nodes to higher capability ‘master’ nodes. We argue that for certain data fusion-based services this means that compute intensive algorithms, often shunned as impractical for sensor networks, are in fact a viable possibility. Using localization as an example, we show how accurate results may be obtained by leveraging this capability without the use of specialized hardware or high configuration detail; both of which are standard approaches to the problem when computation is at a premium. Specifically, we propose a mathematical optimization-based framework for localization based on proximity constraints. Most variants of localization can be cast into this framework depending on the kinds of input available (e.g. ranging). We show accurate results, and exploit a technique from distributed optimization to divide the problem into pieces suitable for computation at the master-level nodes. We conclude with remarks on the general implications of this example for tiered systems, with pointers on how it is likely to be applicable to other problems such as power-aware routing.publicMultiscaled Actuated SensingRethinking Data Fusion-Based Services in Tiered Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt7905k0292011-07-02T19:59:36Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7905k029Dhariwal, Amitauthorzhang, binauthorde Menezes Pereira, Arvind AntonioauthorOberg, CarlauthorStauffer, BethauthorMoorthi, StefanieauthorCaron, David A.authorSukhatme, Gauravauthor2006-01-01As part of our research, we have designed and developed sensor-actuated network for marine monitoring. The network consists of ten static buoy nodes and one mobile robotic boat for real-time in-situ measurements and analysis of chemical, physical and biologically pertinent phenomena governing the abundance of micro-organisms at relevant spatio-temporal scales. The goal of the network is to obtain high-resolution information on the spatial and temporal distribution of plankton assemblages in aquatic environments using the in situ presence afforded by the network, and to make possible network-enabled robotic sampling of hydrographic features of interest.publicAquaticNAMOS: Networked Aquatic Microbial Observing Systemarticlelocaloai:escholarship.org:ark:/13030/qt58b3k6412011-07-02T19:59:32Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/58b3k641Girod, LewisauthorRoch, Marie Aauthor2006-12-11In recent decades, the cost of acoustic technologies has declined dramatically. Advances in networks, storage devices, and power management have made it practical to consider the remote location of sensors. Nonetheless, many challenges remain for the fabrication, deployment, and use of remote sensors.This paper provides an overview of the issues involved in developing remote acoustic sensors. We discuss physical design and the integration of components, data storage and communication issues, signal acquisition and classification, and the relationship of these issues to power usage requirements.publicSystemsacoustic transducer arraysaudio signal processingsignal classificationsignal detectionaudio processingaudio signal acquisitiondata storageremote acoustic sensorAn Overview of the Use of Remote Embedded Sensors for Audio Acquisition and Processingarticlelocaloai:escholarship.org:ark:/13030/qt3zm539zd2011-07-02T19:58:51Z am 3u Center for Embedded Network SensingVol. 132, no. 4 (Jan. 2007) 350-357eScholarship, University of Californiahttps://escholarship.org/uc/item/3zm539zdKim, DohyunauthorGoldberg, Ira B.authorJudy, J Wauthor2007-01-01An electrochemical system that consists of a silver electrode in 0.01 M sodium hydroxide electrolyte was investigated in an effort to develop a sensitive in situ analytical method for nitrate. Cyclic voltammetry demonstrated that the proposed system has a high normalized sensitivity (2.47 A s½ V−½ M⁻¹ cm⁻²), compared to more complex electroanalytical schemes. Double- potential-step chronocoulometry was used to maximize the signal-to-noise ratio (SNR), and minimize interference from dissolved oxygen in the electrolyte. The integration period for double- potential-step chronocoulometry was determined by optimizing the extended Cottrell equation. The integrated current is proportional to nitrate up to 10 mM and the average detection limit is approximately 1.7 µM. Dissolved oxygen does not degrade performance. To examine the potential interference of other ions when analyzing nitrate, we measured the electrode response to 1000 µM each of NO₂⁻, Cl⁻, PO₄³⁻, SO₄²⁻, F⁻, CO₃²⁻, BO₂⁻, K⁺, Ca²⁺, and Sr²⁺ with and without 1000 µM nitrate. Interference is negligible for most of the ions when nitrate is absent (i.e., 1% of the response to equimolar nitrate). However, interference is substantial (20% increase or decrease in the electrode response to nitrate) for PO₄³⁻, Ca²⁺, and Sr²⁺ when equimolar nitrate is present.publicSensorsChronocoulometric Determination of Nitrate on Silver Electrode and Sodium Hydroxide Electrolytearticlelocaloai:escholarship.org:ark:/13030/qt9q5083rh2011-07-02T19:58:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9q5083rhKoushanfar, FarinazauthorTaft, NinaauthorPotkonjak, Miodragauthor2006-04-23We address the problem of energy efficient sensing by adaptively coordinating the sleep schedules of sensor nodes while guaranteeing that values of sleeping nodes can be recovered from the awake nodes within a user’s specified error bound. Our approach has two phases. First, development of models for predicting measurement of one sensor using data from other sensors. Second, creation of the maximal number of subgroups of disjoint nodes, each of whose data is sufficient to recover the measurements of the entire sensor network. For prediction of the sensor measurements, we introduce a new optimal non-parametric polynomial time isotonic regression. Utilizing the prediction models, the sleeping coordination problem is abstracted to a domatic number problem and is optimally solved using an ILP solver. To capture evolving dynamics of the instrumented environment, we monitor the prediction errors occasionally to trigger adaptation of the models and domatic partitions as needed. Experimental evaluations on traces of a medium size network with temperature and humidity sensors indicate that the method can extend the lifetime of the network by a factor of 4 or higher even for a strict error target.publicMultiscaled Actuated SensingSleeping Coordination for Comprehensive Sensing Using Isotonic Regression and Domatic Partitionsarticlelocaloai:escholarship.org:ark:/13030/qt91p587cn2011-07-02T19:58:37Z am 3u Center for Embedded Network SensingVol. 5, no. 3 (Sep. 2006) 149-156eScholarship, University of Californiahttps://escholarship.org/uc/item/91p587cnLee, Alexander S.authorMahapatro, MrinalauthorCaron, David A.authorRequicha, AriauthorStauffer, BethauthorThompson, Mark E.authorZhou, Chongwuauthor2006-09-06Aureococcus anophagefferens, a harmful bloom-forming alga responsible for brown tides in estuaries of the Middle Atlantic U.S., has been investigated by atomic force microscopy for the first time, using probes functionalized with a monoclonal antibody specific for the alga. The rupture force between a single monoclonal antibody and the surface of A. anophagefferens was experimentally found to be 246±11 pN at the load rate of 12 nN/s. Force histograms for A. anophagefferens and other similarly-sized algae are presented and analyzed. The results illustrate the effects of load rates, and demonstrate that force-distance measurements can be used to build biosensors with high signal-to-noise ratios for A. anophagefferens. The methods described in this paper can be used, in principle, to construct sensors with single-cell resolution for arbitrary cells for which monoclonal antibodies are available.publicAquaticatomic force microscopyAureococcus anophagefferensbiosensorsforce-distance measurementssingle-cell identificationWhole-Cell Sensing for a Harmful Bloom-Forming Microscopic Alga by Measuring Antibody-Antigen Forcesarticlelocaloai:escholarship.org:ark:/13030/qt81s2s0t22011-07-02T19:58:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/81s2s0t2Ryffel, SebiauthorStathopoulos, ThanosauthorMcIntire, DustinauthorKaiser, WilliamauthorThiele, Lotharauthor2009-01-09This paper presents a novel energy attribution and accounting architecture for multi-core systems that can provide accurate, per-process energy information of individual hardware components. We introduce a hardwareassisted direct energy measurement system that integrates seamlessly with the host platform and provides detailed energy information of multiple hardware elements at millisecond-scale time resolution. We also introduce a performance counter based behavioral model that provides indirect information on the proportional energy consumption of concurrently executing processes in the system. We fuse the direct and indirect measurement information into a low-overhead kernel-based energy apportion and accounting software system that provides unprecedented visibility of per-process CPU and RAM energy consumption information on multi-core systems. Through experimentation we show that our energy apportioning system achieves an accuracy of at least 96% while impacting CPU performance by less than 0:6%.publicSystemsEnergy accountingMulti-core SystemsAccurate Energy Attribution and Accounting for Multi-core Systemsarticlelocaloai:escholarship.org:ark:/13030/qt5xq4j0152011-07-02T19:58:09Z am 3u Center for Embedded Network SensingVol. 6, no. 3 (Jan. 2007) 372-387eScholarship, University of Californiahttps://escholarship.org/uc/item/5xq4j015Schnetzer, AstridauthorMiller, Peter E.authorSchaffner, RebeccaauthorStauffer, BethauthorJones, Burton H.authorWeisberg, Stephen B.authorDiGiacomo, Paul M.authorBerelson, William M.authorCaron, David A.author2007-01-01Abundances of Pseudo-nitzschia spp. and concentrations of particulate domoic acid (DA) were determined in the Southern California Bight (SCB) along the coasts of Los Angeles and Orange Counties during spring and summer of 2003 and 2004. At least 1500 km2 were affected by a toxic event in May/June of 2003 when some of the highest particulate DA concentrations reported for US coastal waters were measured inside the Los Angeles harbor (12.7 μg DA L−1). Particulate DA levels were an order of magnitude lower in spring of 2004 (February and March), but DA concentrations per cell at several sampling stations during 2004 exceeded previously reported maxima for natural populations of Pseudo-nitzschia (mean = 24 pg DA cell−1, range = 0–117 pg DA cell−1). Pseudo-nitzschia australis dominated the Pseudo-nitzschia assemblage in spring 2004. Overall, DA-poisoning was implicated in >1400 mammal stranding incidents within the SCB during 2003 and 2004. Ancillary physical and chemical data obtained during our regional surveys in 2004 revealed that Pseudo-nitzschia abundances, particulate DA and cellular DA concentrations were inversely correlated with concentrations of silicic acid, nitrogen and phosphate, and to specific nutrient ratios. Particulate DA was detected in sediment traps deployed at 550 and 800 m depth during spring of 2004 (0.29–7.6 μg DA (g sediment dry weight)−1). The highest DA concentration in the traps was measured within 1 week of dramatic decreases in the abundances of Pseudo-nitzschia in surface waters. To our knowledge these are the deepest sediment trap collections from which DA has been detected. Sinking of the spring Pseudo-nitzschia bloom may constitute a potentially important link between DA production in surface waters and benthic communities in the coastal ocean near Los Angeles. Our study indicates that toxic blooms of Pseudo-nitzschia are a recurring phenomenon along one of the most densely populated coastal stretches of the SCB and that the severity and magnitude of these events can be comparable to or greater than these events in other geographical regions affected by domoic acid.publicAquaticDomoic acidHarmful algal bloomsLos AngelesPseudo-nitzschiaSouthern CaliforniaBlooms of Pseudo-nitzschia and Domoic Acid in the San Pedro Channel and Los Angeles Harbor Areas of the Southern California Bight, 2003–2004articlelocaloai:escholarship.org:ark:/13030/qt2059b99k2011-07-02T19:56:49Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2059b99kTrifa, VladauthorGirod, LewisauthorCollier, Travis C.authorBlumstein, DanielauthorTaylor, C Eauthor2007-01-01To understand the complex interactions among animals within an ecosystem, biologists need to be able to track their location and social interactions. There are a variety of factors that make this difficult. We propose using adaptive, embedded networked sensing technologies to develop an efficient means for wildlife monitoring. This paper surveys our research; we demonstrate how a self-organizing system can efficiently conduct real-time acoustic source detection and localization using distributed embedded devices.publicMultiscaled Actuated SensingAutomated Wildlife Monitoring Using Self-Configuring Sensor Networks Deployed in Natural Habitatsarticlelocaloai:escholarship.org:ark:/13030/qt9c16b6dd2011-07-02T19:55:20Z am 3u Center for Embedded Network SensingVol. 32, no. 6 (Nov. 2006) 839-845eScholarship, University of Californiahttps://escholarship.org/uc/item/9c16b6ddYao, Kauthor2006-11-01Sensor network has experienced world-wide explosive interests in recent years. It combines the technology of modern microelectronic sensors, embedded computational processing systems, and modern computer and wireless networking methodologies. In this overview paper, we first provide some rationales for the growth of sensor networking. Then we discuss various basic concepts and hardware issues. Four basic application cases in the US. National Science Foundation funded Ceneter for Embedded Networked Sensing program at UCLA are presented. Finally, six challenging issues in sensor networks are discussed. Numerous references including relevant papers, books, and conferences that have appeared in recent years are given.publicMultiscaled Actuated Sensingsensor networkswireless communicationembedded processinginformation processingenvironmental monitoringhealth care systemroboticsautomated manufacturingSensor Networking: Concepts, Applications, and Challengesarticlelocaloai:escholarship.org:ark:/13030/qt48p8j92g2011-07-02T19:55:16Z am 3u Center for Embedded Network SensingVol. 115, no. 1 (Jan. 2006) 5406-5415eScholarship, University of Californiahttps://escholarship.org/uc/item/48p8j92gYao, Kauthor2006-01-01publicArray Processing of Acoustic and Vibrational Sourcesarticlelocaloai:escholarship.org:ark:/13030/qt9bk265632011-07-02T19:54:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9bk26563Rahimi, MohammedauthorAhmadian, ShaunauthorZats, DavidauthorLaufer, RafaelauthorEstrin, Dauthor2006-10-31Large-scale networks of battery-operated wireless image sensors have become technologically feasible. However, it is still unclear how we can benefit from large-scale deployments of imagers. In this paper, we argue that using a large number of low-power image sensors is useful and necessary in many cases. For instance, occluded environments cannot be efficiently observed with a small number of cameras. In this case, distributed imagers can provide better coverage due to minimum infrastructure requirements and availability in large numbers. Additional benefits, such as pose diversity, statistical advantages, and multiple perspectives are discussed in detail using application examples and qualitative arguments.publicMultiscaled Actuated SensingDistributed ImagingEnergy ConsumptionData SizeComplexityComputationMagic of Numbers in Networks of Wireless Image Sensorsarticlelocaloai:escholarship.org:ark:/13030/qt5vx6b93s2011-07-02T19:54:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5vx6b93sHyman, JoshauthorGraham, EricauthorHansen, MarkauthorEstrin, Dauthor2007-01-01There exist many natural phenomena where direct measurement is either impossible or extremely invasive. To obtain approximate measurements of these phenomena we can build prediction models based on other sensing modalities such as features extracted from data collected by an imager. These models are derived from controlled experiments performed under laboratory conditions, and can then be applied to the associated event in nature. In this paper we explore various different methods for generating such models and discuss their accuracy, robustness, and computational complexity. Given sufficiently computationally simple models, we can eventually push their computation down towards the sensor nodes themselves to reduce the amount of data required to both flow through the network and be stored in a database. The addition of these models turn in-situ imagers into powerful biological sensors, and image databases into useful records of biological activity.publicMultiscaled Actuated SensingImagers as Sensors: Correlating Plant CO-2 Uptake with Digital Visible-Light Imageryarticlelocaloai:escholarship.org:ark:/13030/qt5dj0231s2011-07-02T19:54:22Z am 3u Center for Embedded Network SensingVol. 91, no. 8 (Jan. 2003) 1154-1162eScholarship, University of Californiahttps://escholarship.org/uc/item/5dj0231sChen, JoeauthorYip, LauthorElson, JauthorWang, H BauthorManiezzo, DanielaauthorHudson, Ralph E.authorYao, KauthorEstrin, Dauthor2003-01-01Advances in microelectronics, array processing, and wireless networking have motivated the analysis and design of low-cost integrated sensing, computing, and communicating nodes capable of performing various demanding collaborative space–time processing tasks. In this paper, we consider the problem of coherent acoustic sensor array processing and localization on distributed wireless sensor networks. We first introduce some basic concepts of beamforming and localization for wide-band acoustic sources. A review of various known localization algorithms based on time-delay followed by least-squares estimations as well as the maximum–likelihood method is given. Issues related to practical implementation of coherent array processing, including the need for fine-grain time synchronization, are discussed. Then we describe the implementation of a Linux-based wireless networked acoustic sensor array testbed, utilizing commercially available iPAQs with built-in microphones, codecs, and microprocessors, plus wireless Ethernet cards, to perform acoustic source localization. Various field-measured results using two localization algorithms show the effectiveness of the proposed testbed. An extensive list of references related to this work is also included.publicMultiscaled Actuated Sensingad hoc networkbeamformingdistributed sensor networkmicrophone arraysource localizationtime synchronizationwireless networkCoherent Acoustic Array Processing and Localization on Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt3ks9198m2011-07-02T19:54:16Z am 3u Center for Embedded Network SensingVol. 91, no. 11 (Nov. 2003) 1922-1933eScholarship, University of Californiahttps://escholarship.org/uc/item/3ks9198mRequicha, Ariauthor2003-11-01Nanorobotics encompasses the design, fabrication, and programming of robots with overall dimensions below a few micrometers, and the programmable assembly of nanoscale objects. Nanorobots are quintessential nanoelectromechanical systems (NEMS) and raise all the important issues that must be addressed in NEMS design: sensing, actuation, control, communications, power, and interfacing across spatial scales and between the organic/inorganic and biotic/abiotic realms. Nanorobots are expected to have revolutionary applications in such areas as environmental monitoring and health care.This paper begins by discussing nanorobot construction, which is still at an embryonic stage. The emphasis is on nanomachines, an area which has seen a spate of rapid progress over the last few years. Nanoactuators will be essential components of future NEMS.The paper's focus then changes to nanoassembly by manipulation with scanning probe microscopes (SPMs), which is a relatively well established process for prototyping nanosystems. Prototyping of nanodevices and systems is important for design validation, parameter optimization and sensitivity studies. Nanomanipulation also has applications in repair and modification of nanostructures built by other means. High-throughput SPM manipulation may be achieved by using multitip arrays.Experimental results are presented which show that interactive SPM manipulation can be used to accurately and reliably position molecular-sized components. These can then be linked by chemical or physical means to form subassemblies, which in turn can be further manipulated. Applications in building wires, single-electron transistors, and nanowaveguides are presented.publicSensorsatomic force microscopymicroactuatorsmicroassemblingmicromotorsmicrorobotsmicrosensorsnanotechnologyrobot programmingNanorobots, NEMS, and Nanoassemblyarticlelocaloai:escholarship.org:ark:/13030/qt80b3w8d82011-07-02T19:54:12Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/80b3w8d8Ganeriwal, SaurabhauthorKansal, AmanauthorSrivastava, Mani B.author2004-04-26Actuation ability introduces a fundamentally new design dimension in wireless ad-hoc sensor networks, allowing the network to adaptively reconfigure and repair itself in response to unpredictable run-time dynamics. One of the key network resources in these systems is energy and several uncontrollable factors lead to situations where a certain segment of the network becomes energy constrained before the remaining network. The performance gets limited due to the constrained sections. We argue that in this scenario, instead of rendering the complete network useless, the remaining energy resources should be reorganized to form a new functional topology in the network. We present methods for the network to be aware of its own integrity and use actuation to improve performance when needed. This capability of the system is referred to as “self aware actuation”.In this paper, we consider a network where nodes (or a subset of the nodes) have traction ability. The network uses mobility to repair the coverage loss in the area being monitored by it. We present a completely distributed energy aware algorithm (referred to as Co-Fi) for coordinated coverage fidelity maintenance in sensor networks. The energy overheads of mobility are incorporated in the algorithm, thus leaving no hidden costs. Our preliminary analysis shows that Co-Fi can significantly help improve the usable lifetime of these networks.publicMultiscaled Actuated Sensingad hoc networkswireless sensor networkscoverageactuationmobilitysensing rangeSelf Aware Actuation for Fault Repair in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt9tv972pr2011-07-02T19:54:06Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9tv972prGirod, LewisauthorElson, JauthorCerpa, Alberto EauthorStathopoulos, ThanosauthorRamanathan, NithyaauthorEstrin, Dauthor2004-06-27Many Wireless Sensor Network (WSN) applications are composed of a mixture of deployed devices with varying capabilities, from extremely constrained 8-bit “Motes” to less resource-constrained 32-bit “Microservers”. EmStar is a software environment for developing and deploying complex WSN applications on networks of 32-bit embedded Microserver platforms, and integrating with networks of Motes. EmStar consists of libraries that implement message-passing IPC primitives, tools that support simulation, emulation, and visualization of live systems, both real and simulated, and services that support networking, sensing, and time synchronization. While EmStar’s design has favored ease of use and modularity over efficiency, the resulting increase in overhead has not been an impediment to any of our current projects.publicSystemsdistributed programmingwireless communicationsignal processing systemsintegrated environmentsEmStar: A Software Environment for Developing and Deploying Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt7hz3r28p2011-07-02T19:53:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7hz3r28pWhang, DanielauthorXu, NingauthorRangwala, SumitauthorChintalapudi, KrishnaauthorGovindan, RameshauthorWallace, J Wauthor2004-05-05An innovative networked embedded sensing system for structural health monitoring is currently being developed. This sensor network has been prototyped in the laboratory, and will be deployed in a series of forced-vibration tests involving a full-scale, four-story office building in the next coming months. The low-power wireless seismic sensor system enables the acquisition of 15–30 channels of 16-bit accelerometer data at 128 Hz over a wireless network. The advantage of such a system is its trivial deployability. This system contains several novel communication, data compression and time synchronization algorithms in order to deal with the low data rates and the lossy nature of low-power radios, as well as the inability to use GPS at each individual measurement. Our experiments indicate high-fidelity data acquisition, at the cost of slightly higher latency dictated by the radio data rates.publicSystemsDevelopment of an Embedded Networked Sensing System for Structural Health Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt2st0t8cf2011-07-02T19:51:41Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2st0t8cfZhao, YonggangauthorGovindan, RameshauthorEstrin, Dauthor2002-03-17It is important to have continuously updated information about network resources and application activities in a wireless sensor network after it is deployed in an unpredictable environment. Such information can help notify users of resource depletion or abnormal activities. However, constrained by the low user-to-node ratio, limited energy and bandwidth resources, it is infeasible to extract state of each individual node. In this paper, we propose an approach to construct abstracted scans of sensor network health by applying in-network aggregation of network state. Specifically, we design a residual energy scan which approximately depicts the remaining energy distribution within a sensor network. Simulations show that our approach has good scalability and energy-efficiency characteristics, compared to continuously extracting the residual energy level individually from each node.publicSystemsWireless Sensor NetworkAggregationNetwork InstrumentationResidual Energy Scans for Monitoring Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt5sd603sk2011-07-02T19:51:14Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5sd603skXu, YaauthorBien, SolomonauthorMori, YutakaauthorHeidemann, JohnauthorEstrin, Dauthor2003-01-23In wireless ad hoc networks and sensor networks, energy use is in many cases the most important constraint since it corresponds directly to operational lifetime. This paper presents two topology control protocols that extend the lifetime of dense ad hoc networks while preserving connectivity, the ability for nodes to reach each other. Our protocols conserve energy by identifying redundant nodes and turning their radios off. Geographic Adaptive Fidelity (GAF) identifies redundant nodes by their physical location and a conservative estimate of radio range. Cluster-based Energy Conservation (CEC) directly observes radio connectivity to determine redundancy and so can be more aggressive at identifying duplication and more robust to radio fading. We evaluate these protocols through analysis, extensive simulations, and experimental results in two wireless testbeds, showing that the protocols are robust to variance in node mobility, radio propagation, node deployment density, and other factors.publicSystemsWireless sensor networksAdaptive topologyTopology controlEnergy conservationTopology Control Protocols to Conserve Energy in Wireless Ad Hoc Networksarticlelocaloai:escholarship.org:ark:/13030/qt8ft930f92011-07-02T19:50:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8ft930f9Kansal, AmanauthorYuen, EricauthorKaiser, W JauthorPottie, GregoryauthorSrivastava, Mani Bauthor2003-11-30The performance of a sensor network may be best judged by the quality of application specific information return. The actual sensing performance of a deployed sensor network depends on several factors which cannot be accounted at design time, such as environmental obstacles to sensing. We propose the use of mobility to overcome the effect of unpredictable environmental influence and to adapt to run time dynamics. Now, mobility with its dependencies such as precise localization and navigation is expensive in terms of hardware resources and energy constraints, and may not be feasible in compact, densely deployed and widespread sensor nodes. We present a method based on low complexity and low energy actuation primitives which are feasible for implementation in sensor networks. We prove how these primitives improve the detection capabilities with theoretical analysis, extensive simulations and real world experiments. The significant coverage advantage recurrent in our investigation justifies our own and other parallel ongoing work in the implementation and refinement of self-actuated systems.publicMultiscaled Actuated Sensingsensing performanceactuationcoveragerun-time adaptationSensing Uncertainty Reduction Using Low Complexity Actuationarticlelocaloai:escholarship.org:ark:/13030/qt8j4033n72011-07-02T19:50:29Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8j4033n7Kim, DohyunauthorGoldberg, IraauthorJudy, J Wauthor2004-05-05Nitrate-sensing system that consists of a micromachined sensor substrate, nitrate-permeable membrane, integrated microfluidic channels, and standard fluidic connectors has been designed, fabricated, assembled, and tested. Our microsensor was designed for in-situ monitoring of nitrate concentrations in ground water. A silver electrode was patterned for amperometric nitrate detection. An electrochemically oxidized silver electrode was used as a reference electrode. Microfluidic channels were fabricated as flow paths for the eluent and ground-water sample to the microelectrochemical (MEC) cell. The sensor also incorporates a nitrate-permeable membrane that is used for selective measurement of nitrate. The sensor has a linear response over concentration ranging from 1 μM to 1 mM.publicSensorsMicromachined Amperometric Nitrate Sensor with Integrated Microfluidicsarticlelocaloai:escholarship.org:ark:/13030/qt4c0876vh2011-07-02T19:50:24Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4c0876vhGanesan, DeepakauthorCerpa, Alberto EauthorYe, WeiauthorYu, YanauthorZhao, YonggangauthorEstrin, Dauthor2003-12-09The emergence of sensor networks as one of the dominant technology trends in the coming decades [1] has posed numerous unique challenges to researchers. These networks are likely to be composed of hundreds, and potentially thousands of tiny sensor nodes, functioning autonomously, and in many cases, without access to renewable energy resources. Cost constraints and the need for ubiquitous, invisible deployments will result in small sized, resource-constrained sensor nodes.While the set of challenges in sensor networks are diverse, we focus on fundamental networking challenges in this paper. The key networking challenges in sensor networks that we discuss are: (a) supporting multi-hop communication while limiting radio operation to conserve power, (b) data management, including frameworks that support attribute-based data naming, routing and in-network aggregation, (c) geographic routing challenges in networks where nodes know their locations, and (d) monitoring and maintenance of such dynamic, resource-limited systems. For each of these research areas, we provide an overview of proposed solutions to the problem and discuss in detail one or few representative solutions. Finally, we illustrate how these networking components can be integrated into a complex data storage solution for sensor networks.publicSystemsNetworking Issues in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt1dc7f6s02011-07-02T19:50:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1dc7f6s0Kim, DohyunauthorGoldberg, IraauthorJudy, J Wauthor2004-05-05A nitrate-sensing system that consists of a micromachined sensor substrate, anion-permeable membrane, integrated microfluidic channels, and standard fluidic connectors has been designed, fabricated, assembled, and tested. Our microsensor was designed for in-situ monitoring of nitrate concentrations in ground water. A silver electrode was patterned for amperometric nitrate detection. An electrochemically oxidized silver electrode was used as a reference electrode. Microfluidic channels were fabricated as flow paths to the microelectrochemical (MEC) cell for the eluent and ground-water sample. The sensor also incorporates an anion-permeable membrane that is used for selective measurement of nitrate. With standard addition methods, linear calibration curves have been obtained and the detection limit is ~1 μM. To test selectivity, the sensor response to a 100-μM-nitrate solution and a mixture of nitrate and interfering ions (100 μM each of NO₃⁻, PO₄⁻², SO₄⁻³, F⁻, and Cl⁻) were compared. Despite the 400% increase in total ionic concentration, the sensor output only increased 13.9%.publicSensorsMicromachined Amperometric Nitrate Sensor with an Anion Permeable Membranearticlelocaloai:escholarship.org:ark:/13030/qt1s75j5br2011-07-02T19:49:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1s75j5brBatalin, MaximauthorRahimi, MohammedauthorYu, YanauthorLiu, DuoauthorKansal, AmanauthorSukhatme, GauravauthorKaiser, W JauthorHansen, MarkauthorPottie, GregoryauthorSrivastava, Mani BauthorEstrin, Dauthor2004-05-05Monitoring of environmental phenomena with embedded networked sensing confronts the challenges of both unpredictable variability in the spatial distribution of phenomena, coupled with demands for a high spatial sampling rate in three dimensions. For example, low distortion mapping of critical solar radiation properties in forest environments may require two-dimensional spatial sampling rates of greater than 10 samples/m² over transects exceeding 1000 m². Clearly, adequate sampling coverage of such a transect requires an impractically large number of sensing nodes. This paper describes a new approach where the deployment of a combination of autonomous-articulated and static sensor nodes enables sufficient spatiotemporal sampling density over large transects to meet a general set of environmental mapping demands.To achieve this we have developed an embedded networked sensor architecture that merges sensing and articulation with adaptive algorithms that are responsive to both variability in environmental phenomena discovered by the mobile sensors and to discrete events discovered by static sensors. We begin by describing the class of important driving applications, the statistical foundations for this new approach, and task allocation. We then describe our experimental implementation of adaptive, event aware, exploration algorithms, which exploit our wireless, articulated sensors operating with deterministic motion over large areas. Results of experimental measurements and the relationship among sampling methods, event arrival rate, and sampling performance are presented.publicCall and Response: Experiments in Sampling the Environmentarticlelocaloai:escholarship.org:ark:/13030/qt8fg8r34p2011-07-02T19:49:02Z am 3u Center for Embedded Network SensingVol. 11, no. 6 (Dec. 2004) 70-77eScholarship, University of Californiahttps://escholarship.org/uc/item/8fg8r34pElson, JauthorGirod, LewisauthorEstrin, Dauthor2004-12-20Recently, increasing research attention has been directed toward wireless sensor networks: collections of small low-power nodes, physically situated in the environment, that can intelligently deliver high-level sensing results to the user. As the community has moved into more complex design efforts — large-scale, long-lived systems that truly require self-organization and adaptivity to the environment — a number of important software design issues have arisen. To make software robust, we must carefully observe its behavior and understand its failure modes. However, many of these failures are not manifested until deployment time. Channel and storage limitations make visibility into a deployed system difficult, hindering our understanding of failure modes. Simulation is difficult to apply; the network’s physical situatedness makes it sensitive to subtleties of sensors and wireless communication channels that are difficult to model. In this article we describe EmStar, a PC-based software framework that aims to make development easier by improving system visibility. EmStar’s novel execution environments encompass pure simulation, true in-situ deployment, and hybrid modes that combine simulation with real wireless communication and sensors situated in the environment.publicSystemslarge-scale systemssoftware architecturetelecommunication computingtelecommunication network reliabilitywireless sensor networksEmStar: Development with High System Visibilityarticlelocaloai:escholarship.org:ark:/13030/qt633348fz2011-07-02T19:48:56Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/633348fzKim, JuyoulauthorPark, YeonjeongauthorHarmon, T Cauthor2005-05-05This work describes the integration of data acquisition (DAQ) hardware and software for the purpose of acquiring not only data but real-time transport model parameter estimates in the context of subsurface flow and transport problems. Integrated DAQ parameter estimation systems can be used to reduce data storage requirements, trigger event recognition and more detailed sampling actions, and otherwise enhance remote monitoring capabilities. The contaminant transport problem is posed here as the analogous heat transfer problem in a three-dimensional, intermediate-scale physical aquifer model. A constant source of warm water is fed into a sandy aquifer undergoing steady, unidirectional flow. The spatial distribution of temperature in the medium is monitored over time using 17 thermocouples embedded in the medium. These sensors log temperatures via conventional analog-to-digital conversion hardware driven by commercially available DAQ software (LabVIEW™). Parameter estimation routines programmed in MATLAB™-based M-files are embedded in the LabVIEW DAQ routine and access parameter estimation libraries, such as the descent method employed here, via the Internet. The integrated DAQ parameter estimation system is demonstrated for the estimation of (1) the thermal dispersion coefficients (analogous to mass dispersion coefficients), given a known heat source; and (2) the location of a heat source, given known thermal dispersion coefficients. In both cases, the parameter estimation procedure is executed repeatedly as the data are acquired. For the case of source location, the effect of the number of sensors on the parameter estimation procedure is also demonstrated. Reasonable parameter estimates are provided rapidly during both the transient and steady-state phases of the experiments, with accuracy increasing with time and with the number of observations employed.publicReal-Time Model Parameter Estimation for Analyzing Transport in Porous Mediaarticlelocaloai:escholarship.org:ark:/13030/qt373730782011-07-02T19:47:43Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/37373078Cerpa, Alberto EauthorWong, J LauthorPotkonjak, MiodragauthorEstrin, Dauthor2005-01-01Recently, several studies have analyzed the statistical properties of low power wireless links in real environments, clearly demonstrating the differences between experimentally observed communication properties and widely used simulation models. However, most of these studies have not performed in depth analysis of the temporal properties of wireless links. These properties have high impact on the performance of routing algorithms.Our first goal is to study the statistical temporal properties of links in low power wireless communications. We study short term temporal issues, like lagged autocorrelation of individual links, lagged correlation of reverse links, and consecutive same path links. We also study long term temporal aspects, gaining insight on the length of time the channel needs to be measured and how often we should update our models.Our second objective is to explore how statistical temporal properties impact routing protocols. We studied one-to-one routing schemes and developed new routing algorithms that consider autocorrelation, and reverse link and consecutive same path link lagged correlations. We have developed two new routing algorithms for the cost link model: (i) a generalized Dijkstra algorithm with centralized execution, and (ii)a localized distributed probabilistic algorithm.publicTemporal Properties of Low Power Wireless Links: Modeling and Implications on Multi-Hop Routingarticlelocaloai:escholarship.org:ark:/13030/qt4nw064642011-07-02T19:47:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4nw06464Kansal, AmanauthorRahimi, MohammedauthorKaiser, W JauthorSrivastava, Mani BauthorPottie, GregoryauthorEstrin, Dauthor2004-05-05A key challenge in sensor networks is ensuring the sustainability of the system at the required performance level, in an autonomous manner. Sustainability is a major concern because of severe resource constraints in terms of energy, bandwidth and sensing capabilities in the system. In this paper, we envision the use of a new design dimension to enhance sustainability of in sensor networks—the use of controlled mobility. We argue that this capability can alleviate resource limitations and improve system performance by adapting to deployment demands. While opportunistic use of external mobility has been considered before, the use of controlled mobility is largely unexplored. We also outline the research issues associated with effectively utilizing this new design dimension. Two system prototypes are described to present first steps towards realizing the proposed vision.publicControlled Mobility for Sustainable Wireless Networksarticlelocaloai:escholarship.org:ark:/13030/qt0xn8s4mt2011-07-02T19:46:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0xn8s4mtGreenstein, BenauthorMar, ChristopherauthorPesterev, AlexauthorFarshchi, ShahinauthorKohler, EddieauthorJudy, J WauthorEstrin, Dauthor2006-11-01Small-form-factor, low-power wireless sensors—motes—are convenient to deploy, but lack the bandwidth to capture and transmit raw high-frequency data, such as human voices or neural signals, in real time. Local filtering can help, but we show that the right filter settings depend on changing ambient conditions and network effects such as congestion, which makes them dynamic and unpredictable. Mote collection systems for high-frequency data must support iteratively-tuned, deployment-specific filter settings as well as fast sampling.VANGO, our software system for high-frequency data collection, achieves these goals via integrated processing across network tiers. Bandwidth-limited sensor nodes reduce data in network but rely on microservers, which have greater computational capabilities and a wider scope of observation, to plan how. VANGO provides a cross-platform library for data transformation, measurement, and classification; a fast and low-jitter data acquisition system for motes; and a mechanism to control mote and microserver signal processing. With VANGO we have developed new applications: the first acoustic collection system for motes responsive to changing environmental conditions and user interests, and the first neural spike acquisition application capable of supporting a network of nodes.publicsignal processing frameworkssensor networksmotesacousticshealth monitoringCapturing High-Frequency Phenomena Using a Bandwidth-Limited Sensor Networkarticlelocaloai:escholarship.org:ark:/13030/qt3s75m3592011-07-02T19:42:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3s75m359Yan YuauthorDeepak GanesanauthorLewis GirodauthorRamesh GovindanauthorDeborah Estrinauthor2003-01-01Sensor networks have drawn much attention because of their promising applications in environmental monitoring, seismology, and military surveillance. Despite increasing interest, sensor network research is still in its initial phase. Few real systems have been deployed and little data is available to test proposed protocol and data management designs. Most sensor network research to date uses randomly generated data input to simulate their systems. Some researchers have proposed using environmental monitoring data obtained from remote sensing or in-situ instrumentation. In many cases, neither of these approaches is relevant, because they are either collected from regular grid topology, or too coarse grained. This paper proposes to use synthetic data generation techniques to generate irregular data topology from data sets measured on a grid. To tackle this problem, we investigate the use of the available sparsely sampled data sets, model the spatio-temporal correlation in these data sets, and generate irregular topology data based on empirical models of the experimental data. Our goal is to more realistically evaluate sensor network system designs before large scale field deployment. In obtaining these synthetic data sets, we draw heavily on techniques developed in geo-statistics and other spatial interpolation techniques, but appropriately modify them for the application at hand. Our evaluation results on the radar data set of weather observations shows that the spatial correlation of the original and synthetic data are similar. Moreover, visual comparison shows that the synthetic data retains interesting properties (e.g., edges) of the original data. Our case study on the DIMENSIONS system demonstrates how synthetic data helps to evaluate the system over an irregular topology, and points out the need to improve the algorithm.publicData Modeling and Synthetic Data Generation For Fine-Grained Networked Sensingarticlelocaloai:escholarship.org:ark:/13030/qt73k4d7cz2011-07-02T19:41:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/73k4d7czHeemin ParkauthorWeiping LiaoauthorKing Ho TamauthorMani B. SrivastavaauthorLei Heauthor2003-01-01This report presents a simulation framework for quantifying power consumption in a unified way that reflects the node level performance to network-wide power estimation.publicA Unified Network and Node Level Simulation Framework for Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt5085h7qt2011-07-02T19:41:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5085h7qtAmit DhariwalauthorGaurav S. SukhatmeauthorAristides A. Requichaauthor2003-01-01This paper presents an approach, inspired by bacterial chemotaxis, for robots to navigate to sources using gradient measurements and a simple actuation strategy (biasing a random walk). To appear in IEEE International Conference on Robotics and Automation, Apr 2004.publicBacterium-inspired Robots for Environmental Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt1f27k34v2011-07-02T19:40:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1f27k34vHenri Dubois-FerriereauthorDeborah Estrinauthor2004-01-01In a data-gathering sensor network with multiple sinks, it is often unnecessary and redundant for each sink to flood the entire network with its queries. We propose a simple scoping scheme with the property that a query originated at a sink will be forwarded only to the subset of nodes for whom that sink is the closest sink.publicEfficient and Practical Query Scoping in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt2s2878kf2011-07-02T19:40:13Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2s2878kfYan YuauthorDeborah EstrinauthorRamesh GovindanauthorMohammad Rahimiauthor2004-01-01Sensor network research is still in its infancy. Few real systems are deployed and little experimental data from sensor networks is available to test proposed protocol designs. Due to lack of experimental data and sophisticatedmodels derived fromsuch data, most data processing algorithms from the sensor network literature are evaluated with data generated from simple parametric models. We identify a few widely-studied classes of problems that are potentially sensitive to data input: Statistics estimation of the field data; Data compression; and Field estimation. We use them as examples to investigate the dependency of algorithm performance on data. For each class of problem, given the selected problem and algorithm instance, we systematically study how the algorithm performance varies across a range of data input. We also demonstrate how different data input can change the algorithm performance dramatically, the performance comparison between two algorithms may even change depending on the different data inputs. In the end, we propose our synthetic data generation framework and recommend evaluating algorithms across a wide range of data input.publicUse more realistic data models to evaluate sensor network data processing algorithmsarticlelocaloai:escholarship.org:ark:/13030/qt3fq8x53k2011-07-02T19:39:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3fq8x53kJuyoul KimauthorThomas C. Harmonauthor2005-01-01Embedded networked sensing (ENS) technology is rapidly expanding into environmental application domains, where network coverage issues are tightly coupled to the environmental media and observational objectives. The goal of this work is to develop and test an automated, real-time ENS coverage design algorithm in the context of an environmental simulation model. The algorithm combines the application of a genetic algorithm (GA) with a deterministic inverse modeling approach, and is demonstrated in the context of a bench-scale groundwater test bed in which the ENS objective is to identify the location of a heat source. More specifically, optimal sensor locations are determined in real-time using a GA-based evolution algorithm whose objective function is the trace minimization of the model-prediction covariance with respect to potential sensor locations. Next, measured temperature sensor data and a descent-based inverse technique are used to update the source location estimate. The procedure is repeated (2 monitoring sensors per design cycle) until a pre-determined sensor supply is exhausted. Two transient heat transport experiments are undertaken in which sources placed upstream of a manually configurable ENS comprising thermocouples for mapping spatiotemporal temperature distributions. The ENS approach successfully corrected an erroneous initial source location estimate and incrementally improved upon this estimate with the addition of new sensors. A point of diminishing improvement was eventually achieved at an imperfect source location estimate. This result was most likely the result of discrepancies between the mathematical model and the experimental system. For the dual-source experiment, the real-time source locator converged on a single source between the two sources, indicating the need for more sophisticated logic for increasingly complex cases.publicGenetic Algorithm-Based Embedded Networked Sensing Design Coupled to an Environmental Simulatorarticlelocaloai:escholarship.org:ark:/13030/qt9nv096c42011-07-02T19:38:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9nv096c4Thanos StathopoulosauthorLewis GirodauthorJohn HeidemannauthorDeborah Estrinauthor2005-01-01We propose Mote Herding, a new system architecture for large scale, heterogeneous sensor networks. Mote herding uses a mix of many 8-bit sensor nodes (motes) and fewer but more powerful 32-bit sensor nodes (microservers). Mote herding groups motes into flocks that are connected via a multihop network to a microserver acting as a shepherd. Shepherds exploit their greater communications and compute power to form an overlay network, with many flocks joining to form a herd. By keeping each flock small and utilizing several shepherds, the herd can support many nodes with better latency, reliability, and energy efficiency than homogeneous architectures.publicMote Herding for Tiered Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt20f0w8wn2011-07-02T19:36:14Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/20f0w8wnSean Askayauthor2006-01-01New Visualization Tools for Environmental Sensor Networks: Using Google Earth as an Interface to Micro-Climate and Multimedia DatasetspublicNew Visualization Tools for Environmental Sensor Networks: Using Google Earth as an Interface to Micro-Climate and Multimedia Datasetsarticlelocaloai:escholarship.org:ark:/13030/qt3hp231kb2011-07-02T19:24:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3hp231kbKaren KimauthorWesley UeharaauthorRichard GuyauthorDeborah EstrinauthorRamesh GovindanauthorMichael HamiltonauthorMark HansenauthorTom HarmonauthorJenny JayauthorWilliam KaiserauthorGreg PottieauthorMani SrivastavaauthorGaurav SukhatmeauthorYu-Chong Taiauthor2006-01-01CENS programs are designed to create an educational pipeline to graduate school, provide support and development to our graduate student affiliates and increase the diversity of our Center and those pursuing education and careers in science and engineering.publicEDU 1: CENS Graduate and Undergraduate Education Programsarticlelocaloai:escholarship.org:ark:/13030/qt06t6m9mb2011-07-02T19:24:14Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/06t6m9mbAllen HuskerauthorIgor StubailoauthorMartin LukacauthorAlma QuezadaauthorSteven SkinnerauthorIrving FloresauthorPaul DavisauthorRichard GuyauthorDeborah Estrinauthor2006-01-01The deployment phase of CENS equipment began this year within MASE (Middle America Subduction Experiment), a collaboration involving UCLA, the California Institute of Technology (CIT), and the Universidad Nacional Autnoma de Mexico (UNAM). The CENS 50 radio-linked sites joined the 50 stand-alone sites of CIT in Mexico. Scientifically, we will be mapping the subducted slab beneath Mexico, examining the propagation of seismic waves through Mexico, and searching for slow earthquakes. The array has already yielded receiver function images of the slab 10 times clearer than previous images due to the density of the array. We are beginning to develop an inversion algorithm of the data for a 3d velocity tomography. We are hoping the images are clear enough to answer where the subducting slab is. Currently it is unclear if the slab is still there or if it has torn away from the top. Due to a lack of deep seismicity from within the slab, a network of this density is the best way to determine its location.publicSEI 1: Design, Installation, and Performance of a Delay Tolerant Seismic Network in Mexicoarticlelocaloai:escholarship.org:ark:/13030/qt3rr8b4dr2011-07-02T19:24:04Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3rr8b4drMike LiuauthorSiyang ZhengauthorCharlott KwongauthorNan LiauthorYu-Chong TaiauthorChi Ming HoauthorNarvey L. Kasdanauthor2006-01-01Lab-on-Chip aquatic microorganism analysis system is a new initiative that aims to expedite research in marine biology using chip-based technology. The miniaturized device reduces the total sample and detection time. Also, the chips can be fabricated in large quantities with minimal cost so many experiments can be run in parallel. Our project is organized into two main research areas. First, we would like to develop a chip to monitor the content of the sea water and assess the concentration of different algae. The chip will take in sea water sample, separate the cells based on size, and a downstream impedance sensor will count the number of cells. The second main area of this project is to make a chip that can culture algae and screen for factors inducing toxin production. The exact causes for Peudo-nitzschia to produce toxins are unclear, and we would like to make a chip that cultures Pseudo-nitzschia under different growing conditions.publicSEN 1: Lab-on-a-Chip Aquatic Microorganism Analysis Systemarticlelocaloai:escholarship.org:ark:/13030/qt2q0293w32011-07-02T19:23:44Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2q0293w3Amit DhariwalauthorBin ZhangauthorArvind PereiraauthorCarl ObergauthorBeth StaufferauthorStefanie MoorthiauthorDavid CaronauthorGaurav Sukhatmeauthor2006-01-01As part of our research, we have designed and developed a sensor-actuated network for marine monitoring. The network consists of ten static buoy nodes and one mobile robotic boat for real-time in-situ measurements and analysis of chemical, physical and biologically pertinent phenomena governing the abundance of micro-organisms at relevant spatio-temporal scales. The goal of the network is to obtain high-resolution information on the spatial and temporal distribution of plankton assemblages in aquatic environments using the in situ presence afforded by the network, and to make possible network-enabled robotic sampling of hydrographic features of interest.publicMAS 5: NAMOS: Networked Aquatic Microbial Observing Systemarticlelocaloai:escholarship.org:ark:/13030/qt4f55v9pj2011-07-02T19:23:07Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4f55v9pjDong-U LeeauthorHyungjin KimauthorSteve TuauthorJohn Villasenorauthor2006-01-01We examine energy tradeoffs in image communication on highly resource-constrained platforms. A JPEG encoder is implemented on Cyclops which allows a compression factor of six for commonly-used 64x64 and 128x128 images without visible quality degradation. Although computation cost is increased due to the encoding step, the communication cost is much reduced due to the reduction in data size. Results indicate significant energy and speed improvements compared to transmitting uncompressed images.publicEnergy Tradeoffs in Image Communication among Resource-Constrained Image Sensors (SYS 11)articlelocaloai:escholarship.org:ark:/13030/qt40b4z6032011-07-02T19:22:33Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/40b4z603Stefanie MoorthiauthorBeth StaufferauthorCarl ObergauthorGaurav SukhatmeauthorDavid Caronauthor2006-01-01Lingulodinium polyedrum is a marine, bioluminescent dinoflagellate that is a common red tide species and potential toxin producer (yessotoxin) along a large expanse of the coast of Southern California. Little is known about the factors leading to bloom formation, or its impact on planktonic food webs. Bloom abundances can reach over 1000 cells/ml, events in which the interplay of physical forces (wind and surface currents) and of algal behavior (vertical migration) presumably play an important role. Using the CENS laboratory test bed, we have examined the pattern and timing of vertical migration by the dinoflagellate in a 2m water column on an 11h:13h light:dark photoperiod. Species-specific detection and enumeration of this organism was accomplished using an 18S rDNA-based quantitative real-time PCR (qPCR) approach developed in our lab. Positive phototaxis of L. polyedrum resulted in dense aggregations of the dinoflagellate within the top few centimetres of the water column during the light period, while cells were evenly distributed during the night.publicInvestigating vertical migration and bloom dynamics of a red tide dinoflagellate: Laboratory observations and a novel sensing approach. (AQU 2)articlelocaloai:escholarship.org:ark:/13030/qt50p1p17v2011-07-02T19:21:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/50p1p17vYeonjeong ParkauthorJose SaezauthorThomas Harmonauthor2006-01-01In an effort to balance water reuse and protect groundwater quality when irrigating with reclaimed water, an adaptive management scheme with feedback control has been developed and is currently undergoing testing. Several multi-level sensing arrays (pylons) equipped with soil moisture, temperature, and nitrate sensors are installed in Palmdale and in Merced backyard. The pylon is coupled to a simulation and management algorithm to optimize irrigation scheduling. Specifically, a nonlinear programming-based control algorithm, referred to as Receding Horizon Feedback Control (RHFC), is proposed to maximize water reuse and maintain nitrate concentration in groundwater below the regulatory threshold. Each pylon supplies the irrigation scheduling algorithm with real-time field information about water infiltration and distribution, nitrate propagation, and heat transport (in support of evaporation estimates). A test bed for Palmdale deployment is set up in Merced backyard. An automatic flow controller system for sprinkling is equipped with data acquisition board to interface with sensors and management algorithm in MATLABTM. One-dimensional simulators are used to estimate key local soil hydraulic and transport parameters in near real time.publicAutomatic Feedback Control In Support of Sensor Networks to Monitor Nitrate in Palmdale and in Merced Backyard (CON 2)articlelocaloai:escholarship.org:ark:/13030/qt65t5476p2011-07-02T19:21:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/65t5476pJason GordonauthorKris PorterauthorLisa ShirachiauthorRachel ScollansauthorVictor ChenauthorWilliam Kaiserauthor2005-01-01The ability to remotely monitor the dynamics of a natural environment is an increasingly important avenue for investigating and ultimately protecting natural ecosystems and safeguarding public health. NIMS provides a new capability for mobile monitoring of complex environments. NIMS enables the first spatiotemporally resolved sensing capability for applications including microclimate characterization in the forest canopy by using this new multisensor module.publicMultisensor Module for Networked Infomechanical Systemsarticlelocaloai:escholarship.org:ark:/13030/qt9s5164k62011-07-02T19:21:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9s5164k6Michael HamiltonauthorEric GrahamauthorDeborah EstrinauthorPhil RundelauthorVanessa Rivera Del RioauthorRichard GuyauthorSean Askayauthor2005-01-01EMISSARY is a field-portable interface for advanced data visualization, modelling, and data exploration of sensor micronets. Geographical Information Systems (GIS) and a Graphical User Interface (GUI) are combined to expand our understanding of data collected from sensors in the field. EMISSARY supplies real-time access to current and archived data and data models. It also provides field guidance and facilitates the process of sensor configuration, calibration, testing and debugging. It provides researchers with the capability to produce models using past and real-time data for hypothesis testing and experiment planning.publicTER1: From Sensor to Scientist: Emissary and Cyberinfrastructure for Sensor Networks in Terrestrial Ecological Researcharticlelocaloai:escholarship.org:ark:/13030/qt3kd1844w2011-07-02T19:21:20Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3kd1844wArnaud BenahmedauthorBranden BroughauthorChih-Ming Hoauthor2005-01-01Networked censors require miniaturized censors for realistic large scale deployment. We are developing an entire new versatile molecular sensor based on the plasmonic band gap phenomenon. It uses evanescent electromagnetic waves called surface plasmons which are collective excitation of electrons on an interface metal/dielectric. Contrary to existing surface plasmon based sensors, our detection mechanism is based on the properties of the propagation of surface plasmon waves through periodic nanostructures. This allows for a robust and embed- able detection system for on-field deployment.publicSEN4: Surface Plasmon Band Gap Sensor for robust, label-free, on-field biological detectionarticlelocaloai:escholarship.org:ark:/13030/qt6kd570mj2011-07-02T19:20:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6kd570mjMohammad RahimiauthorDeborah EstrinauthorMani SrivastavaauthorRick Baer (Agilent)authorJay Warrior (Agilent)author2005-01-01Despite their increasing sophistication, wireless sensor networks still do not exploit the most powerful of the human senses: vision. Indeed, vision provides humans with unmatched capabilities to distinguish objects and identify their importance. This work seeks to provide wireless sensor networks with similar capabilities by exploiting emerging, cheap, low-power and small form factor CMOS imaging technology. In fact, we go beyond the stereo capabilities of human vision, and exploit the large scale of sensor networks to provide multiple, widely different perspectives of physical phenomena. We have developed a small camera device called Cyclops that bridges the gap between the computationally constrained wireless sensor nodes such as Motes, and CMOS imagers which, while low power and inexpensive, are nevertheless designed to mate with resource-rich hosts. Cyclops enables development of new class of vision applications that span across wireless sensor network.publicSYS3: Cyclops: Image Based Sensing for Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt0j38w23x2011-07-02T19:20:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0j38w23xBen GreensteinauthorChris MarauthorEddie KohlerauthorDeborah Estrinauthor2005-01-01The Sensor Network Application Construction Kit (SNACK) provides a new configuration language, component and service library, and compiler that make it easier to develop efficient sensor network applications. The goal is the construction of smart application service libraries: high-level libraries that implement concepts like routing trees and periodic sensing, and that combine automatically into efficient programs. Important language features include flexible control over component sharing and transitive arrow connections, which let independently-implemented services knit themselves into integrated control flow paths.publicSYS2: Building High Rate Applications Easily through More Flexible Component Compositionarticlelocaloai:escholarship.org:ark:/13030/qt8tp8x7g22011-07-02T19:20:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8tp8x7g2Ben TitzerauthorDaniel K. LeeauthorJens Palsbergauthor2005-01-01We present Avrora, a cycle-accurate instruction-level sensor network simulator. Avrora scales to networks of up to 10,000 nodes and performs as much as 20 times faster than previous simulators with equivalent accuracy, handling as many as 25 nodes in real-time. Avrora emulates sensor nodes based on the Mica2 hardware platform, including the AVR microcontroller, its internal devices such as timers and serial port connections, and external devices such as the CC1000 radio. Avrora provides a platform for simulating, analyzing, and debugging sensor network programs in precise detail.publicSYS1: Avrora: Scalable Sensor Network Simulation with Precise Timingarticlelocaloai:escholarship.org:ark:/13030/qt5rx6w6wx2011-07-02T19:19:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5rx6w6wxPhil RundelauthorEric GrahamauthorWilliam Kaiserauthor2005-01-01There is a critical need to apply developing technologies to problems of scaling tropical ecosystem and ecophysiological processes, from local levels up to stands, communities, biomes, and beyond. Such scaling is critical if we are to accurately predict changes in the composition, structure, and dynamics and understand how those changes are likely to affect tropical rainforests. Fixed and mobile sensor arrays provide a solution to meet these needs. CENS is collaborating with the Organization for Tropical Studies on planning for a large network of fixed and mobile sensors at the La Selva Biological Station in Costa Rica.publicA Rainforest Ecological Portalarticlelocaloai:escholarship.org:ark:/13030/qt75r5t68h2011-07-02T19:19:14Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/75r5t68hBrian FulkersonauthorStefano SoattoauthorWilliam SwensonauthorMike AllenauthorMichael Hamiltonauthor2005-01-01The ability to do robust, meaningful research with minirhizotron images is currently limited by the amount of time that can be spent by a human expert classifying the data. This poster focuses on presenting progress along a path towards the automated analysis of these images. It shows custom software that has been developed to aid in the classification process and filters which locate structures of interest in some cases.publicTowards Automated Analysis of Minirhizotron Imagesarticlelocaloai:escholarship.org:ark:/13030/qt46v9d5t72011-07-02T19:19:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/46v9d5t7Heemin ParkauthorJonathan FriedmanauthorVids SamantaauthorJeff BurkeauthorMani B. Srivastavaauthor2005-01-01We present the Ping-Pong mote, a new light sensing module for the Mica mote platform. The Ping-pong mote achieves performance comparable to a commercial light intensity meter, while conforming to the size and energy constraints imposed by its application in wireless sensor networks. The Ping-pong mote was developed to replace the Mica sensor board (MTS310) whose slow response time and narrow dynamic range in light intensity capture is unsuitable to many applications, including media production. The Ping-pong mote features significantly improved SNR due to its adoption of high-end photo sensors, amplification and conversion circuits coupled with active noise suppression, application-tuned filter networks, and a noise-attentive manual layout. Unlike the MTS310, the Ping-pong mote can capture RGB color intensity (for color temperature calculation) and incident light angle (which discerns the angle of ray arrival from the strongest source). Our prototype demonstrated significantly faster response time (> 6x) and a much wider dynamic range (> 10x) in light intensity measurement as compared with the MTS310. The light-angle estimation results were well correlated with an average error of just 2.63 degree.publicA New Light Sensing Module for Mica Motesarticlelocaloai:escholarship.org:ark:/13030/qt1m3650212011-07-02T19:19:04Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1m365021Phil RundelauthorEric GrahamauthorMichael StealeyauthorYeung LamauthorGerald KimauthorVictor Chenauthor2005-01-01Cool ambient air temperatures and warm soil and rock surfaces in alpine fellfield ecosystems produce sharp and dynamic spatial gradients in surface temperatures, with profound impacts on plant ecophysiology. Spot measurements of plant and soil surface temperatures are not sufficient to understand the complexity of this environment. Thermal scanner instrumentation mounted on a NIMS-RD system can provide dense measurements of spatial and temporal patterns of surface temperatures across a fellfield habitat, as well as a photographic log of transect position.publicTemporal and spatial scales of temperature change in an alpine fell field ecosystemarticlelocaloai:escholarship.org:ark:/13030/qt1fp5g7mz2011-07-02T19:18:57Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1fp5g7mzBeth A. StaufferauthorGaurav S. SukhatmeauthorBin ZhangauthorAmit DhariwalauthorCarl ObergauthorDavid A. CaronauthorAristides Requichaauthor2005-01-01Developing predictive models for aquatic microbial populations requires very fine spatial and temporal resolution of data that traditional monitoring techniques are typically incapable of providing. The need for continuous presence in an environment combined with the desire for directed (intelligent) sampling has prompted the development of a sensor network to address these needs. The network incorporates low-energy demand, and highly adaptable sensors which exploit recent advances in computer networking and robotics to process sensor data and ensure high data fidelity. The coordination of stationary sensor nodes and mobile sensing using a sampling robot allow for efficient collection of samples from features of interest, exemplified in studies of a recent cyanobacterial bloom in Lake Fulmor, California.publicUse of Embedded Networked Sensing for the Study of Cyanobacterial Bloom Dynamicsarticlelocaloai:escholarship.org:ark:/13030/qt21d6t51h2011-07-02T19:18:51Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/21d6t51hYeonjeong ParkauthorJuyoul KimauthorJose SaezauthorThomas C. Harmonauthor2005-01-01An issue associated with agricultural irrigation using reclaimed wastewater is the potential threat to underlying groundwater quality. A prime example is nitrate, which serves as a fertilizing agent but has the potential to leach into groundwater. In order to balance water reuse and groundwater protection, intelligent irrigation monitoring and management systems are required to manage water reuse. In this work, a wirelessly networked sensor array is being designed for deployment at an agricultural research plot.publicManagement of Soil Moisture and Nitrate Transport Using Sensor Networks and Feedback Controlarticlelocaloai:escholarship.org:ark:/13030/qt3759x1cq2011-07-02T19:18:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3759x1cqTatyana BendikovauthorNicole JurischauthorMallory DavidsonauthorThomas Harmonauthor2005-01-01This work describes the development and testing of a sensitive and selective potentiometric nitrate microsensor that are scaleable to large, dense sensor networks required to study environmental systems. We have developed flexible, miniature and inexpensive nitrate sensors by electropolymerizing pyrrole onto carbon fiber substrates, using nitrate as a dopant. Carbon microfibers were found to be an excellent substitute to expensive conductive materials, such as glassy carbon or platinum. The electrodes with a 3-5 micron layer of NO3 -doped polypyrrole (PPy) exhibited a promising lifetime (at least 2 month without changes in sensitivity and linear response), fast response times (seconds), and sensitivity competitive to commercial nitrate ISE.publicPotentiometric Nitrate Sensors in the Form of Plant Rootsarticlelocaloai:escholarship.org:ark:/13030/qt3m69g5642011-07-02T19:18:37Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3m69g564Victor ChenauthorWillie ChenauthorRobert GilbertauthorBrett JordanauthorGerald KimauthorYeung LamauthorMichael StealeyauthorRichard PonauthorWilliam KaiserauthorEric GrahamauthorPhil Rundelauthor2005-01-012005 CENS Summer Intern:NIMS (Networked Info-Mechanical Systems) is a sensor system utilizing fixed and actuated sensors to monitor environmental changes. A new, rapidly deployable NIMS (NIMS RD) allows for more mobility and versatility in the field. With short-term deployments, data is able to be read quickly and in-field calibrations are possible. A variety of sensor nodes can be attached to the system allowing it to work in diverse environments. As a result of this, many deployments have been possible and much environmental data has been collected at Medea Creek, the James Reserve, and the White Mountains.publicNIMS A Rapid Deployable Approacharticlelocaloai:escholarship.org:ark:/13030/qt51w6x5tx2011-07-02T19:18:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/51w6x5txXi WangauthorFabio SilvaauthorJohn Heidemannauthor2004-01-01The Follow-me application is a sensor network based active visitor guidance system. It is easy-to-deploy and self-configurable. In the system, sensor nodes with LEDs and buttons are deployed throughout a building, one on the wall at each office doorway. They blink lights to indicate a path through the building, guiding a visitor with a "breadcrumb trail" to the destination. The most important aspect of the follow-me application is location-aware configuration. GPS and similar systems determine location today, but they require substantial infrastructure in the environment or on sensor nodes to locate nodes in a physical coordinate system. For many applications, logical location - the relationship of nodes with each other and their environment - can be more important than physical location. For example, distance along a road and presence of intersections may be more relevant than Euclidean coordinates for applications that track or guide drivers. We developed deployment order, a new algorithm to configure logical location in a sensor network. Deployment order exploits node deployment patterns and simple user interactions to define logical topologies in a completely distributed manner with little human input.publicInfrastructureless Location Aware Configuration for Sensor Networks and the Follow-Me Applicationarticlelocaloai:escholarship.org:ark:/13030/qt8686v73p2011-07-02T19:18:07Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8686v73pArun SomasundaraauthorAman KansalauthorDavid JeaauthorMani Srivastavaauthor2004-01-01Wireless Sensor network is a network of sensor nodes. A sensor node has, in addition to computation, sensing and wireless communication capability. A network of these nodes is deployed to measure the ecological properties like temperature etc. There is a base station which collects the data from these nodes. The data reaches the base station wirelessly by the multihop communication path established by the sensor nodes. The sensor nodes are resource constrained, and communication is the major consumer of battery resource. The nodes near the base station relay other further nodes data, and as a result die earlier. Once they are gone, the network is effectively disconnected. We explore the option of a chargeable mobile base station traversing the network, and the nodes transfer the data when it is near. This improves the lifetime of the network. The work involves designing network algorithms for the system, and adaptive speed control strategies for the mobile.publicControlled Mobility for Increased Lifetime in Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt97p9r4552011-07-02T19:18:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/97p9r455Andrew ParkerauthorAthanasios StathopolousauthorJeremy ElsonauthorLewis GirodauthorNing XuauthorAlberto CerpaauthorRamesh GovindanauthorDeborah Estrinauthor2004-01-01There are many wireless sensor network applications that need to operate in the face of lossy or disconnect-prone links. In these situations, traditional MANET protocols are inadequate and higher layer protocols that require continuous end-to-end connectivity will fail. The IEEE Delay Tolerant Networking Research Group (DTNRG) investigates architectural and protocol design principles that provide for communication in performance-challenged environments. This demonstration shows how some of the ideas out DTNRG can be adopted for sensor networks, specifically Bundles as the basic unit of communication, and Custody Transfer as a policy for when to delete data.publicDelay Tolerant Networking for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt22m9b4q12011-07-02T19:17:47Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/22m9b4q1Heemin ParkauthorJonathan FriedmanauthorJeff BurkeauthorMani Srivastavaauthor2004-01-01In this poster, we are exploring sensor networks expansion to media and film production environment. We have derived unique requirements and research challenges in this new driver application domain and proposed1) a deployment-time service to guide a person for rapid and robust sensor deployment, and 2) sensor network system to collect data in synchronized with the film camera frame rate. We evaluated our first implementation of Augmented Recording System in TV studio and we built a method to measure latency between sensor readings and video frames in a systematic way.publicAugmenting Film Video Footage with Sensor Dataarticlelocaloai:escholarship.org:ark:/13030/qt6kc1s4p02011-07-02T19:17:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6kc1s4p0Kelli A. MillwoodauthorMelissa S. CookauthorKathy GriffisauthorJoe WiseauthorJeffery BockertauthorChristine L. BorgmanauthorWilliam A. Sandovalauthor2004-01-01Students face several challenges when trying to make sense of data from sensor networks. The Sensing the Environment Inquiry Module was developed to help students learn about adaptation by investigating ecological data from a local sensor network. Sixty-one students from three Los Angeles-area schools piloted the inquiry unit in Spring 2004. Students at all three schools made significant learning gains.publicCENSing the Environment Middle and High School Students Learningarticlelocaloai:escholarship.org:ark:/13030/qt0491d78j2011-07-02T19:17:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0491d78jJason MeltzerauthorRakesh GuptaauthorMing-Hsuan YangauthorStefano SoattoauthorUCLA Vision LabauthorHonda Research Instituteauthor2004-01-01We propose a vision-based SLAM algorithm incorporating feature descriptors derived from multiple views of a scene, incorporating illumination and viewpoint variations. These descriptors are extracted from video and then applied to the challenging task of wide baseline matching across significant viewpoint changes. The system incorporates a single camera on a mobile robot in an extended Kalman filter framework to develop a 3D map of the environment and determine egomotion. At the same time, the feature descriptors are generated from the video sequence, which can be used to localize the robot when it returns to a mapped location. The kidnapped robot problem is addressed by matching descriptors without any estimate of position, then determining the epipolar geometry with respect to a known position in the map.publicVisual Localization and Mapping with Multiple View Featuresarticlelocaloai:escholarship.org:ark:/13030/qt0w3727q12011-07-02T19:17:27Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0w3727q1Jason HsuauthorAman KansalauthorMani Srivastavaauthor2004-01-01Energy supply is a major challenge for sensor network sustainability. A feasible alternative for enabling long term self-sustained deployments is to supplement or replace the battery supplies with environmentally harvested resources, such as solar power in outdoor environments. However, there are several changes required in system design to support harvested energy such as the capability to learn the environmental energy levels in addition to residual battery. Further, the environmental energy opportunity is significantly variable across space and time. The required taskload should be allocated among multiple nodes as per their energy availabilities to extract maximum performance from the system.publicEnergy Harvesting Support for Sensor Networkingarticlelocaloai:escholarship.org:ark:/13030/qt6k37x5c72011-07-02T19:17:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6k37x5c7Qing HeauthorCarl ChinauthorYu-Chong Taiauthor2004-01-01We have developed an integrated ion liquid chromatography chip, which is integrated with column, frits/filters, injector and conductivity detector. On-chip separation and detection of anions in water (~25ppm) have been successfully demonstrated. The detection limit is estimated to be 1ppm for the common anions. A much-improved 2nd-genaration chip is currently being developed to do better injection, separation, and detection. A palm-sized wireless LC system based on the LC chip is also actively being developed.publicIon Liquid Chromatography On-a-Chip for Multiple Ion Sensingarticlelocaloai:escholarship.org:ark:/13030/qt7bx9v3m02011-07-02T19:17:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7bx9v3m0J. E. HauxauthorT.C. HarmonauthorJ. SaezauthorJ. KimauthorY. ParkauthorN.D. BusekauthorT. SchoellhammerauthorD. Estrinauthor2004-01-01publicEmbedded Network Sensing of Moisture and Nitrate Propagation During Irrigation with Reclaimed Wastewaterarticlelocaloai:escholarship.org:ark:/13030/qt5c6939z32011-07-02T19:16:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5c6939z3Chih-Chieh HanauthorRamKumar RengaswamyauthorRoy Sheaauthor2004-01-01We present SOS, an operating system that enables reconfiguration of wireless sensor networks. These networks are composed of tens of thousands of tiny nodes with very limited resources. Software on the nodes often needs to be updated post-deployment to support feature upgrades, bug fixes or redefined objectives. It is infeasible to physically reprogram each individual node due to the sheer size of the network and the often inhospitable deployment terrain. The SOS architecture enables remote insertion of binary modules into a running kernel without interrupting the system operation. The SOS core is a non-preemptive, event driven microkernel that can operate on platforms with only 4 KB of SRAM. By using a message passing mechanism and dynamic memory, function and memory references are resolved at run time enabling dynamically loadable binary modules. Native execution of the loadable modules results in superior performance over virtual machines. A complex data gathering application has been successfully tested on SOS showing the suitability of this new operating system for the wireless sensor network domain.publicReconfigurable Sensor Networks with SOSarticlelocaloai:escholarship.org:ark:/13030/qt6gq6r67m2011-07-02T19:16:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6gq6r67mBen GreensteinauthorEddie KohlerauthorDeborah Estrinauthor2004-01-01We propose a new configuration language, component and service library, and compiler that make it easier to develop efficient sensor network applications. Our goal is the construction of smart application service libraries: high-level libraries that implement concepts like routing trees and periodic sensing, and that combine automatically into efficient programs. Important language features include flexible control over component sharing and transitive arrow connections, which let independently-implemented services knit themselves into integrated control flow paths. Our language, library, and compiler are collectively called SNACK (Sensor Network Application Construction Kit).publicA Sensor Network Application Construction Kitarticlelocaloai:escholarship.org:ark:/13030/qt2p7553pm2011-07-02T19:16:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2p7553pmRobert GilbertauthorRichard F. AmbroseauthorWilliam J. Kaiserauthor2004-01-01Algal blooms and other negative stream conditions result from dynamic, interrelated factors. Understanding complex biotic and abiotic interactions often require multi-scale, high-resolution measurements. Stream conditions can change rapidly. Conventional low-resolution field sampling may miss important system dynamics. Using the NIMS node technology, we will be able to extract much higher resolution stream data. The nodes will be able to sense and sample a variety of water quality parameters, both abiotic and biotic. The node technology will enable better understanding of the process with which anthropogenic inputs flow through watersheds and change stream ecology. Greater familiarity of these processes will enable better management techniques.publicWater Quality Sensing and Samplingarticlelocaloai:escholarship.org:ark:/13030/qt8sw7c6rc2011-07-02T19:16:41Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8sw7c6rcJonathan FriedmanauthorDavid LeeauthorParixit AgheraauthorAdvaauthor2004-01-01We present a new robotic architecture for research in mobile sensor networks and new interactive gaming environments. The RagoWorld consists of a fully capable, modular mobile platform and an interactive gaming environment, replete with a diverse array of navigational hazards, sensing obstacles, and detectable objects. Currently, Ragobot, the robotic platform, is capable of traversing complex terrains, avoiding moderately sized objects, and reading and writing RFID tags. The next generation of Ragobots will support multiple different sensor node architectures and have more sensing modalities, such as inertial navigation and acoustic tracking.publicReal Action Gaming Robotsarticlelocaloai:escholarship.org:ark:/13030/qt9530278j2011-07-02T19:16:24Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9530278jAmit DhariwalauthorGaurav SukhatmeauthorAristides A.G. RequichaauthorDavid CaronauthorCarl ObergauthorEric Shiehauthor2004-01-01A variety of naturally-occurring and introduced microorganisms adversely impact marine ecosystems. They can affect human health, fisheries and even tourism. However, conditions under which aquatic microorganisms develop are not well understood, and methods for detecting microorganisms are too slow and complex for timely intervention. With the development of technology, sensor networks provide a method to monitor the microorganisms in real time and solve the problem. The ability to autonomously detect, locate and track such phenomena (the source of the induced gradient) would give scientists a tool to monitor and study ecosystems at an unprecedented level of detail. We are in particular motivated by the research goal to track the brown-tide algal blooms in nature and follow their migration over time. We plan to locate these algae and measure their concentrations using a chlorophyll sensor.publicBacterial Navigation and Applications to Sensing in Marine Environmentsarticlelocaloai:escholarship.org:ark:/13030/qt1qh1p0zr2011-07-02T19:16:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1qh1p0zrJerry ZhaoauthorRamesh Govindanauthor2003-01-01Wireless sensor networks promise fine-grain monitoring in a wide variety of environments. Many of these environments (indoor environments or habitats) can be harsh for wireless communication. From a networking perspective, the most basic aspect of wireless communication is the packet delivery performance: the spatio-temporal characteristics of packet loss, and its environmental dependence. These factors will deeply impact the performance of data acquisition from these networks. In this presentation, we report on a systematic medium-scale (up to sixty nodes) measurement of packet delivery in three different environments: an indoor office building, a habitat with moderate foliage, and an open parking lot. Our findings have interesting implications for the design and evaluation of routing and medium-access protocols for sensor networks.publicPacket Delivery Performance in Dense Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt53t615p02011-07-02T19:15:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/53t615p0Thanos StathopoulosauthorJohn HeidemannauthorDeborah Estrinauthor2003-01-01The multicast reliability problem has been studied extensively in the wired internet domain, and, more recently, in wireless and ad-hoc networks as well. In the context of wireless sensor networks, comprised of small, low power and resource-constrained nodes that interact with the physical environment, it remains an active research area. A special case of multicast reliability that is of particular interest in the sensor network domain is code distribution. The ability to add new functionality or perform software maintenance without having to physically reach each individual node is an important piece of a sensor network infrastructure. It becomes critical as sensor networks mature and move toward larger deployment sizes. We present eemoap, an energy-efficient multihop over the air programming mechanism. We discuss the design goals, choices and optimizations for building an efficient code distribution scheme on mica2 motes. The mechanism is evaluated in simulation as well as in an actual mote implementation.publicMulti-hop Code Distribution for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt1mn1f2tw2011-07-02T19:15:49Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1mn1f2twFabio SilvaauthorJohn HeidemannauthorDeborah Estrinauthor2003-01-01None Provided.publicMatching Data Dissemination Algorithms to Application Requirementsarticlelocaloai:escholarship.org:ark:/13030/qt0qp5w05j2011-07-02T19:15:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0qp5w05jRachel ScollansauthorLisa ShirachiauthorKris PorterauthorRichard PonauthorAshutosh VermaauthorWinston WuauthorWilliam Kaiserauthor2003-01-01Method: the experimentation tested various properties under different conditions to characterize the solar cells. Results: established the amount of power the solar array could harvest in a day. Some effects of shading and complete coverage on the solar panel were factored and evaluated. The effects of weather on the solar system were found and analyzed. Conclusions: the battery bank needs a minimum of three days of storage (for short-term deployment) more is optimal. The solar panels should be connected in array to receive more power. To collect more energy from the sun, the array should have an angle of includination of latitude+15 degrees. There is room for additional study on the PV system, particularly the stress on the solar cells due to obstructions. A possible finding upon further study might implement a circuit that cuts off the load if the voltage drops below 11v. Upon testing the solar panels in the field, mounted horizontally, it was found that enough energy was provided to power the node for a 24-hour period.publicSolar Energy Collection and Management for Networked Infomechanical Systems (NIMS)articlelocaloai:escholarship.org:ark:/13030/qt82s9t9pz2011-07-02T19:15:25Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/82s9t9pzJose SaezauthorT. BendikovauthorT. SchoellhammerauthorYeonjeong ParkauthorJuyoul KimauthorMiodrag PotkonjakauthorDeborah EstrinauthorThomas C. Harmonauthor2003-01-01None provided.publicNetworked Sensing of Nitrate in Support of Groundwater Quality Protectionarticlelocaloai:escholarship.org:ark:/13030/qt1232b7rg2011-07-02T19:15:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1232b7rgAbhishek RajgarhiaauthorFred StannauthorJohn Heidemannauthor2003-01-01None Provided.publicMonitoring with a Mix of IR Sensors and Camerasarticlelocaloai:escholarship.org:ark:/13030/qt6sf999tv2011-07-02T19:15:04Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6sf999tvUndergraduates: AhmadiauthorBurkeauthorChanauthorFongauthorGoudarauthorKaoauthorA. LiuauthorLucasauthorParkauthorPorterauthorRibayaauthorScheauthorScollansauthorSharghiauthorShirachiauthorWaughauthorWangrungvichaisriauthorYuen; Graduate Students: GruzdasauthorKansalauthorS. LiuauthorPonauthorRahimiauthorRamanathanauthorTsengauthorVermaauthorWu; Faculty: AmbroseauthorEstrinauthorHamiltonauthorHarmonauthorJayauthorKaiserauthorPottieauthorSrivastavaauthorSukhatmeauthorVillasenorauthor2003-01-01Sensor networks have emerged from research on low power, networked, and embedded systems and are now being applied to important scientific and societal issues. However, current sensor network architectures are unable to determine their most fundamental attribute, the quality of their data return, or sensing uncertainty. This poster will introduce networked infomechanical systems (NIMS), a new distributed embedded computing architecture that exploits a smart infrastructure and sensor diversity, is self-aware of its sensing uncertainty, and is able to adaptively reconfigure itself to maximize sensing fidelity. This will also include a description of the first NIMS prototypes and deployments in environmental science, public health, and physical security.publicNetworked Infomechanical Systems (NIMS)articlelocaloai:escholarship.org:ark:/13030/qt36n1n3kj2011-07-02T19:14:53Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/36n1n3kjYuan LiauthorWei YeauthorJohn Heidemannauthor2003-01-01None Provided.publicSchedule and Latency Control in S-MACarticlelocaloai:escholarship.org:ark:/13030/qt4h79x0362011-07-02T19:14:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4h79x036Ram KumarauthorVlasios TsiatsisauthorMani Srivastavaauthor2003-01-01There is a rich diversity of sensor platforms that are currently available. The platforms cover a large range of MIPS, which is a metric that measures the rate of instruction execution in processors. Also, some of them have specialized architectures (for e.g. DSP, custom H/W on FPGA) which make them efficient for a certain class of applications. However, a single platform alone is not scalable to the large dynamic range of the computational complexity of the sensor network applications...publicHierarchical In-Network Processingarticlelocaloai:escholarship.org:ark:/13030/qt7fz099f22011-07-02T19:13:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7fz099f2Poonam JollyauthorBen HuangauthorAndrew WuauthorDeborah Estrinauthor2003-01-01Current developments in sensing technology will allow sensor networks to be embedded in diverse environments to allow for the collection, manipulation, and transmission of experimental data. One such application of this technology is the Extensible Sensing System, which is designed to be the testbed for sensors and user interfaces to be used in environment sensing...publicWeb Tasking Interface within The Extensible Sensing Systemarticlelocaloai:escholarship.org:ark:/13030/qt8rr5h4h72011-07-02T19:13:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8rr5h4h7Davud JeaauthorArun Agrahara SomasundaraauthorMani Srivastavaauthor2003-01-01None provided.publicAutonomous Intelligent Mobile Micro Serverarticlelocaloai:escholarship.org:ark:/13030/qt6305q4wh2011-07-02T19:13:36Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6305q4whAllen HuskerauthorIgor StubailoauthorMonica KohlerauthorPaul Davisauthor2003-01-01Technological and scientific preparations are occurring for the development of a multi-hop radio-linked seismic array (MHRLSA) of 50 broadband stations (GURALP 3ts) and its first few deployments. A ruggedized data relay device (DRD) is being fabricated using Intel’¡Çs new low power, small form factor stargate motherboard. A DRD will be placed at each node of the array and configured as a local area network (LAN) with station spacing up to 10 km. The objective is to use protocols that have been developed for the world wide web to optimize the acquisition of real time seismic array data...publicSeismic Network Deployment Preparationsarticlelocaloai:escholarship.org:ark:/13030/qt72m1g75k2011-07-02T19:13:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/72m1g75kChih-Chieh HanauthorAthanassios BoulisauthorRoy SheaauthorMani Srivastavaauthor2003-01-01None ProvidedpublicSensorWare in Usearticlelocaloai:escholarship.org:ark:/13030/qt3xh9n7692011-07-02T19:13:03Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3xh9n769Chih-Chieh HanauthorRoy SheaauthorAthanassios BoulisauthorMani Srivastavaauthor2003-01-01None Provided.publicIntegrating Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt53g4v4dx2011-07-02T19:12:58Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/53g4v4dxBenjamin GreensteinauthorDeborah EstrinauthorEddie KohlerauthorDavid Cullerauthor2003-01-01We study and devise methods for detecting spatially distributed features, and in particular, for detecting significant regions of homogeneity. We propose and develop a flexible architecture and macro-programming environment for distributed detection and triggering in sensor networks.publicTriggering on Area: A Systems Approacharticlelocaloai:escholarship.org:ark:/13030/qt5sx2q1bp2011-07-02T19:12:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5sx2q1bpDeepak GanesanauthorBen GreensteinauthorDenis PerelyubskiyauthorDeborah EstrinauthorJohn Heidemannauthor2003-01-01Wireless sensor networks enable dense sensing of the environment, offering unprecedented opportunities for observing the physical world. Centralized data collection and analysis adversely impact sensor node lifetime. Previous sensor network research has, therefore, focused on in network aggregation and query processing, but has done so for applications where the features of interest are known a priori. When features are not known a priori, as is the case with many scientific applications in dense sensor arrays, efficient support for multi-resolution storage and iterative, drill-down queries is essential. Our system demonstrates the use of in-network wavelet-based summarization and progressive aging of summaries in support of long-term querying in storage and communication-constrained networks. We evaluate the performance of our linux implementation and show that: a) wavelet-based hierarchical summarization provides accurate responses to a broad spectrum of spatio-temporal queries with low communication overhead; and b)in a storage-constrained environment, graceful query degradation over time is achieved by networked aging of summaries, such that more useful summaries are retained longer. To our knowledge, no one has examined data aging in the context of highly distributed sensor systems.publicScalable Multi-Resolution Storage and Search in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt0wk5j4dm2011-07-02T19:12:47Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0wk5j4dmKevin N. Gabayanauthor2003-01-01Camera networks can provide images of detected objects that vary in perspective and level of obstruction. To improve the understanding of visual events, vision algorithms are implemented in a wireless sensor network. Methods were developed to fuse data from multiple cameras to improve object identification and location in the presence of obstructions. Training sets of images allow classification of objects into familiar categories. Feature-based object correspondence is used to track multiple objects throughout a sequence of images.publicLow-Level Vision Algorithms for Localization, Classification, and Trackingarticlelocaloai:escholarship.org:ark:/13030/qt94c1b6t92011-07-02T19:12:27Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/94c1b6t9Jessica FengauthorMiodrag Potkonjakauthor2003-01-01Sensor-based measurements are intrinsically prone to errors. One can distinguish two types of errors: systematic and random noise errors. Calibration is the process of validating and/or adjusting the accuracy of a measuring instrument so that the systematic error is calculated and the bias is corrected. Distributed localized in-field calibration of sensor devices in an ad-hoc wireless network is of crucial importance since manual calibration is not feasible and cost-effective. In order to address calibration for an arbitrary system of sensors and actuators and an arbitrary model of systematic errors, we formulate calibration as nonlinear function minimization problem. We start by identifying the necessary and sufficient conditions to solve a specific instance of calibration in a given network. We solve the minimization problem using combination of polak-ribiere conjugate gradient method and singular value decomposition (SVD) algorithms in conjunction with binary search procedure. In addition, we have developed four-phase localized calibration procedure that minimizes the amount of required multi-hop limited-size packet communication and storage...publicModel-based Localized Calibration for Interacting Actuators And Sensorsarticlelocaloai:escholarship.org:ark:/13030/qt66f3q5052011-07-02T19:12:23Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/66f3q505Paul DavisauthorJeremy ElsonauthorDeborah EstrinauthorAllen HuskerauthorIgor Stubailoauthor2003-01-01None Provided.publicWireless Seismic Data Collectionarticlelocaloai:escholarship.org:ark:/13030/qt0p44m1nb2011-07-02T19:12:13Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0p44m1nbAlberto CerpaauthorNaim BusekauthorDeborah Estrinauthor2003-01-01Wireless sensor networks will allow fine-grained monitoring in a wide range of environment (indoor and outdoor). Many of these environments, present very harsh conditions for wireless communication using low-power radios, including multipath/fading effects, reflections from obstacles, and attenuation from foliage. In this work, we introduce scale, a network wireless measurement tool that uses packet delivery as the basic application-level metric. Scale facilitates the gathering of packet delivery statistics using the same hardware platform and in the same environment targeted for deployment. Using up to 55 nodes, we were able to measure and study the connectivity conditions of two hardware platforms, mica 1 and 2 motes, in three different environments: an outdoor habitat reserve, an urban outdoor environment in a university campus, and an office building, under systematically varied conditions. Among other things, we found that there is no clear correlation between packet delivery and distance in an area of more than 50% of the communication range, temporal variations of packet delivery are correlated with mean reception rate of each link, and the percentage of asymmetric links varies from 5% to 30%...publicSCALE: A Tool for Connectivity Assessment in Lossy Environmentsarticlelocaloai:escholarship.org:ark:/13030/qt3s86225c2011-07-02T18:39:28Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3s86225cHyungjin KimauthorDong-U LeeauthorJohn Villasenorauthor2006-01-01We describe a double-tier object localization system consisting of two Cyclopes and a high-resolution PTZ camera. Object detection and recognition are performed on Cyclops via frame differencing and color/size classification. The 3D coordinate of an object of interest is computed by utilizing two Cyclopes for stereoscopic vision. The coordinate is passed to the PTZ camera which takes a high-resolution image of the object for further object classification. Significant energy savings are achieved over traditional single-tier localization systems.publicEnergy-Aware Object Localization Using Heterogneous Image Sensors (SYS 10)articlelocaloai:escholarship.org:ark:/13030/qt1z62t2cg2011-07-02T17:45:25Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1z62t2cgQing HeauthorChanglin PangauthorYu-Chong TaiauthorWeixing LuauthorChih-Ming Hoauthor2003-01-01We are developing a highly sensitive and selective on-chip chromatography-based chemical sensing system, which has the capability to detect most common ions, such as nitrite, nitrate, fluoride, chloride, phosphate and sulphate, in drinking and underground water, with the sensitivity of PPM to PPB level, and within a few minutes or even fractions of a second. The proposed system consists of two major parts: on-chip chromatography system and chemical sensing system. The integrated chromatography system is built with parylene microfluidic technology. Two sensing techniques, one based on conductivity, the other on surface plasmon resonance (SPR), are being explored for their exceptional sensitivity and miniaturization capability.publicOn-Chip Chromatography-Based Chemical Sensingarticlelocaloai:escholarship.org:ark:/13030/qt0h69t3ng2011-07-02T16:52:47Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0h69t3ngHanbiao WangauthorLewis GirodauthorNithya Ramanathanauthor2005-01-01In this paper, we present a platform for collaborative acoustic signal processing, and demonstrate its use with an example application. Our platform is built upon the Stargate Linux-based microserver, and supports synchronized multi-channel acoustic data acquisition. We implement a dataflow-like staged event-driven programming model within the Emstar software framework that simplifies the development of collaborative processing applications. Unlike previous dataflow systems that emphasize real-time constraints, our framework emphasizes collaborative processing across nodes in a distributed system connected by an energy-conserving wireless network with non-deterministic message latency. In our model, an application is constructed by wiring together multiple stages, where each stage is implemented by an EmStar module. The modular approach simplifies development by isolating errors to specific stages, and enables run-time systemreconfigurability by allowing users to swap out implementations of individual stages, and to reconfigure the dataflow at run time.publicA Platform for Collaborative Acoustic Signal Processingarticlelocaloai:escholarship.org:ark:/13030/qt6w02v7jm2011-07-02T16:52:24Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6w02v7jmAman KansalauthorWilliam J KaiserauthorGregory J PottieauthorMani B Srivastavaauthor2005-01-01publicActuation Methods for Enhanced Coveragearticlelocaloai:escholarship.org:ark:/13030/qt8k91k7dz2011-07-02T16:52:14Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8k91k7dzJune ChangauthorLinda SaxauthorKaren KimauthorDeborah EstrinauthorChristine Borgmanauthor2005-01-01Although we have seen progress over the last few decades, women still lag far behind their male counterparts, especially at the doctoral level, in the fields of engineering and computer science. In an attempt to counteract women’�¡�Çs persistent under-representation, pre-college and college experiences have been the focus of both intervention and research endeavors. Despite such efforts, there is one crucial educational component of a woman’�¡�Çs undergraduate experience that remains somewhat of a mystery: the undergraduate research experience. The goals of the project are to:- Identify best practices and strategies inherent in successful undergraduate research programs- Develop a demonstration model of an undergraduate research program that can be shared- Promote women’�¡�Çs long-term commitment to science and engineering.publicWomen@ CENS: A Research Systemarticlelocaloai:escholarship.org:ark:/13030/qt30f452h22011-07-02T16:52:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/30f452h2Roja BandariauthorVictor ChenauthorWillie ChenauthorWendy GwoauthorYeung LamauthorEric LinauthorKris PorterauthorRachel ScollansauthorMichael StealeyauthorLynn WangauthorEric YuenauthorMaxim BatalinauthorRobert GilbertauthorJason GordonauthorAman KansalauthorXiangming KongauthorDuo LiuauthorChris LucasauthorRichard PonauthorMohammad RahimiauthorNithya RamanathanauthorLisa ShirachiauthorArun SomasundaraauthorJeffrey TsengauthorAshutosh VermaauthorWinston WuauthorYan YuauthorRichard AmbroseauthorDeborah EstrinauthorMichael HamiltonauthorMark HansenauthorTom HarmonauthorJenny JayauthorWilliam J. KaiserauthorGregory J. PottieauthorManiauthor2005-01-01Following in the footsteps of the field Networked Infomechanical Systems (NIMS) currently deployed at the James San Jacinto Mountain Reserve in Idyllwild California, two smaller scale NIMS architectures have emerged. The Laboratory Systems (NIMS-LS) provides an experimental testbed for verification of actuated sensing of environmental phenomena. The NIMS-LS System also includes emulation of environmental phenomena (i.e. light distribution in ecosystems). The Rapidly Deployable (NIMS-RD) platform provides a flexible means of sampling environmental phenomena directly with minimal infrastructure, rapid deployability and minimal impact on the environment. NIMS-RD has been deployed at the James San Jacinto Mountain Reserve, Medea Creek in the Santa Monica Mountains, Merced River in Merced CA and White Mountains Research Station near Bishop CA.publicNIMS Laboratory Systemsarticlelocaloai:escholarship.org:ark:/13030/qt99w511qb2011-07-02T16:52:04Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/99w511qbSam IrvineauthorMartin LukacauthorAndrew ParkerauthorAllen HuskerauthorIgor StubailoauthorRichard GuyauthorPaul DavisauthorDeborah Estrinauthor#8194;author#8194;author#8194;author2005-01-01The seismic array is part of the Middle America Subduction Experiment (MASE) partnered with Caltech and Universidad Nacional Aut��ónoma de M��éxico (UNAM). The goals are to map the subducted slab beneath Mexico; examine slow earthquakes observed at this subduction zone; examine volcanic earthquakes observed at this subduction zone; and study the propagation of seismic waves in Mexico City. This will require a line of about 100 stations from Acapulco to Tampico through Mexico City. 50 of the stations are equipped with temporary data-loggers and high-powered 802.11 wireless hardware and antennas. This poster describes the software to achieve an end-to-end autonomous seismic data collection system.publicSeismic Array Software Systemarticlelocaloai:escholarship.org:ark:/13030/qt6df0n5652011-07-02T16:52:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6df0n565Allen HuskerauthorSam IrvineauthorMartin LukacauthorSteve SkinnerauthorAlma QuezadaauthorIgor StubailoauthorRichard GuyauthorPaul Davisauthor2005-01-01The Middle America Subduction Experiment (MASE) is a collaborative project between California Institute of Technology, Universidad Nacional Autonoma de Mexico (UNAM) and UCLA CENS. The project is instrumenting a 500-km transect from Acapulco to Mexico City to Tampico by installing 100 broadband seismometers located every 5 to 20 km. UCLA has installed almost 50 seismometers covering nearly one-half of the line and is using telemetry technology designed by CENS. The entire line will be operating for at least one full year. The seismic data collected by UCLA seismometers is delivered to a RAID array at UCLA in near real time for archiving, processing, and analysis. We are mapping the structure of the Cocos plate subduction zone underneath the Pacific plate along the transect and examine slow earthquakes, volcanic earthquakes and propagation of seismic waves in the heavily populated Mexico City region.publicWide Area Wireless Networks for Geophysicsarticlelocaloai:escholarship.org:ark:/13030/qt3fj6g58j2011-07-02T16:51:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3fj6g58jK. ChintalapudiauthorR. Govindanauthor2003-01-01publicLocalized Edge Detection in Sensor Fieldsarticlelocaloai:escholarship.org:ark:/13030/qt10k610k22011-07-02T16:51:22Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/10k610k2Benjamin GreensteinauthorDeborah EstrinauthorRamesh GovindanauthorSylvia RatnasamyauthorScott Shenkerauthor2003-01-01publicDIFS: A Distributed Index for Features in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt3fm5v6hp2011-07-02T16:51:07Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3fm5v6hpYonggang Jerry ZhaoauthorRamesh GovindanauthorDeborah Estrinauthor2003-01-01publicComputing Aggregates for Monitoring Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt3z34v3jd2011-07-02T16:51:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3z34v3jdH. WangauthorD. EstrinauthorL. Girodauthor2003-01-01publicPreprocessing in a Tiered Sensor Network for Habitat Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt9401q7rc2011-07-02T16:50:56Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9401q7rcA. HowardauthorS. SiddiqiauthorG.S. Sukhatmeauthor2003-01-01publicAn Experimental Study of Localization Using Wireless Ethernetarticlelocaloai:escholarship.org:ark:/13030/qt8t06k2rw2011-07-02T16:50:51Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8t06k2rwA. BoulisauthorS. GaneriwalauthorM. B. Srivastavaauthor2003-01-01publicAggregation in sensor networks: An energy-accuracy trade-offarticlelocaloai:escholarship.org:ark:/13030/qt2h08k1xm2011-07-02T16:50:07Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/2h08k1xmH. JinauthorA. J. YezziauthorS. Soattoauthor2004-01-01publicRegion-based segmentation on evolving surfaces with application to 3D shape and radiance estimationarticlelocaloai:escholarship.org:ark:/13030/qt7694j52g2011-07-02T16:48:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/7694j52gN. XuauthorS. RangwalaauthorK. ChintalapudiauthorD. GanesanauthorA. BroadauthorR. GovindanauthorD. Estrinauthor2004-01-01publicA Wireless Sensor Network for Structural Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt401090d72011-07-02T16:42:16Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/401090d7Gummadi, RamakrishnaauthorKothari, NupurauthorMillstein, ToddauthorGovindan, Rameshauthor2005-01-01Wireless sensor networks research has, till date, made impressive advances in platforms and software services. Research in the area has moved on to consider an essential piece of sensor network technology—support for programming wireless sensor network applications and systems components at a suitably high level of abstraction. Two broad classes of programming models are currently being investigated by the community. One class focuses on providing higher-level abstractions for specifying a node's local behavior in a distributed computation. Examples of this approach include the recent work on node-local or region-based abstractions. By contrast, a second and less-explored class of research considers programming a sensor network in the large called macroprogramming.publicSystemsKairos: A Macro-Programming System for Wireless Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt22q2f5972011-07-02T16:41:01Z am 3u Center for Embedded Network SensingVol. 47, no. 2 (Feb. 2004) 21-23eScholarship, University of Californiahttps://escholarship.org/uc/item/22q2f597Pottie, Gregoryauthor2004-02-01Embed responsibility for privacy into radio-frequency identification tags and other information technology designed to network the physical world.publicMultiscaled Actuated SensingPrivacy in the Global E-Villagearticlelocaloai:escholarship.org:ark:/13030/qt5mh7m01j2011-07-02T16:40:53Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5mh7m01jGaneriwal, SaurabhauthorKumar, RamauthorSrivastava, Mani B.author2003-11-05Wireless ad-hoc sensor networks have emerged as an interesting and important research area in the last few years. The applications envisioned for such networks require collaborative execution of a distributed task amongst a large set of sensor nodes. This is realized by exchanging messages that are timestamped using the local clocks on the nodes. Therefore, time synchronization becomes an indispensable piece of infrastructure in such systems. For years, protocols such as NTP have kept the clocks of networked systems in perfect synchrony. However, this new class of networks has a large density of nodes and very limited energy resource at every node; this leads to scalability requirements while limiting the resources that can be used to achieve them. A new approach to time synchronization is needed for sensor networks.In this paper, we present Timing-sync Protocol for Sensor Networks (TPSN) that aims at providing network-wide time synchronization in a sensor network. The algorithm works in two steps. In the first step, a hierarchical structure is established in the network and then a pair wise synchronization is performed along the edges of this structure to establish a global timescale throughout the network. Eventually all nodes in the network synchronize their clocks to a reference node. We implement our algorithm on Berkeley motes and show that it can synchronize a pair of neighboring motes to an average accuracy of less than 20μs. We argue that TPSN roughly gives a 2x better performance as compared to Reference Broadcast Synchronization (RBS) and verify this by implementing RBS on motes. We also show the performance of TPSN over small multihop networks of motes and use simulations to verify its accuracy over large-scale networks. We show that the synchronization accuracy does not degrade significantly with the increase in number of nodes being deployed, making TPSN completely scalable.publicSystemsSensor NetworksTime SynchronizationPacket DelayClock DriftMedium Access ControlTiming-sync Protocol for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt65j1834w2011-07-02T14:28:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/65j1834wRoja BandariauthorVictor ChenauthorWillie ChenauthorWendy GwoauthorEric LinauthorKris PorterauthorRachel ScollansauthorMichael StealeyauthorLynn WangauthorEric Yuen. NIMS Graduate Students: Maxim BatalinauthorRobert GilbertauthorJason GordonauthorAman KansalauthorXiangming KongauthorDuo LiuauthorChris LucasauthorRichard PonauthorMohammad RahimiauthorNithya RamanathanauthorLisa ShirachiauthorArun SomasundaraauthorJeffrey TsengauthorAshutosh VermaauthorWinston WuauthorYan Yu. NIMS Faculty: Richard AmbroseauthorDeborah EstrinauthorMichael HamiltonauthorMark HansenauthorTom HarmonauthorJenny JayauthorWilliam J. Kaisauthor2005-01-01Rapidly growing stress on the natural environment has created an urgent demand for new environmental exploration systems that operate remotely and autonomously. As sensor networks are applied to these critical environmental monitoring problems, a series of new requirements have emerged for extensive characterization of dynamic phenomena in three-dimensional environments. The unpredictable presence of obstacles to sensing and the inherent temporal evolution of events create limitations for optimal deployment of sensors in the environment.publicNetworked Informechanical Systemsarticlelocaloai:escholarship.org:ark:/13030/qt8n88767h2011-07-02T14:19:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8n88767hPer Henrik BorgstromauthorNils Peter BorgstromauthorMichael J. StealeyauthorMaxim A. BatalinauthorWilliam J. Kaiserauthor2006-01-01NIMS3D is a novel rapidly deployable cabled robot capable of accurate positioning and trajectory tracking within its 3-dimensional span. A generic sensor node is maneuvered by controlling the lengths of three support cables. We present initialization and calibration methods, means to determine the effective range of the robot, trajectory tracking algorithms, and experimental results that show 1) wide applicability for various sensor deployments 2) accurate and repeatable positioning, and 3) responsive and stable trajectory tracking.publicNIMS3D: An Autonomous Three-Dimensional Cabled Robot for Actuated Sensing Applications (MAS 3)articlelocaloai:escholarship.org:ark:/13030/qt3sd731gv2011-07-02T14:17:08Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3sd731gvNi, KevinauthorPottie, G Jauthor2009-01-20Data faults in sensor networks must be marked to ensure accurate inferences. We introduce a two phase semi-realtime end-to-end Bayesian fault detection system for sensor networks. The first phase selects a subset of agreeing sensors from which a model of expected behavior is derived. The second phase uses this subset to derive and tag questionable sensor data. To accurately model the data, we use a hierarchical Bayesian space-time (HBST) model, as compared to the linear autoregressive modeling used in previous works. Applying this system to simulated and real world data, results are excellent when the phenomenon is well modeled by the HBST model. It achieves high detection rates and almost zero false detection rates. Results also indicate that in cases of critically low spatial sampling density a more accurate model is required.publicStatistics and Data PracticesFault DetectionBayesianModelingSensor Network Data Fault Detection Using Bayesian Maximum a Posterior Sensor Selection and Hierarchical Bayesian Space-Time Modelsarticlelocaloai:escholarship.org:ark:/13030/qt5j74t2g22011-07-02T14:16:19Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5j74t2g2Ni, KevinauthorPottie, G Jauthor2009-01-20We present a new application of hierarchical Bayesian space-time (HBST) modeling: data fault detection in sensor networks primarily used in environmental monitoring situations. To show the effectiveness of HBST modeling, we develop a rudimentary tagging system to mark data that does not fit with given models. Using this, we compare HBST modeling against first order linear autoregressive (AR) modeling, which is a commonly used alternative due to its simplicity. We show that while HBST is more complex, it is much more accurate than linear AR modeling as evidenced in greatly reduced false detection rates while maintaining similar, if not better detection rates. HBST modeling reduces false detection rates 41.5% to 96.5% when paired with our simple fault detection method. We also see that HBST modeling is more robust to model mismatches and unmodeled dynamics than linear AR modeling.publicStatistics and Data PracticesFault DetectionModelingSensor Network Data Fault Detection using Hierarchical Bayesian Space-Time Modelingarticlelocaloai:escholarship.org:ark:/13030/qt87h0c2rm2011-07-02T14:10:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/87h0c2rmGautam ThatteauthorUrbashi Mitraauthor2006-01-01Optimal power allocation, in a wireless sensor network with a fusion center, for distributed parameter estimation under a total network power constraint is considered. For the simple star topology, an analysis of the effect of the measurement noise variance on the optimal power allocation policy is presented. As the measurement noise variance increases, the optimal solution evolves from sensor selection to power equalization - the sensor with the lowest SNR is allocated the largest fraction of the total power.Relaying nodes are introduced to form more complicated branch, tree and linear topologies. The optimal power allocation strategies for these topologies are then considered for both amplify-and-forward and estimate-and-forward transmission protocols. Analytical solutions for these cases are intractable, and thus asymptotically (for increasing measurement noise variance) optimal solutions are derived.publicOptimal Power Allocation in Distributed Sensing (SEN 3)articlelocaloai:escholarship.org:ark:/13030/qt5v80v4t32011-07-02T13:50:29Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5v80v4t3R. BandariauthorJ. BurkeauthorV. ChenauthorW. ChenauthorW. GwoauthorE. LinauthorK. PorterauthorR. ScollansauthorM. StealeyauthorL. WangauthorE. YuenauthorR. GilbertauthorJ. GordonauthorA. KansalauthorX. KongauthorS. LiuauthorC. LucasauthorR. PonauthorM. RahimiauthorN. RamanathanauthorL. ShirachiauthorA. SomasundraauthorJ. TsentauthorA. VermaauthorW. WuauthorY. YuauthorR. AmbroseauthorD. EstrinauthorM. HamiltonauthorT. HarmonauthorJ. JayauthorW. KaiserauthorG. PottieauthorM. SrivastavaauthorG. SukhatmeauthorJ. Villasenorauthor2004-01-01Sensor networks have emerged from research on low power, networked, and embedded systems and are now being applied to important scientific issues. Networked Infomechanical Systems, or NIMS, has been developed to exploit infrastructure assisted mobility. With the ability to move and precise knowledge of its own location, NIMS nodes will be able to tackle new areas such as sensing uncertainty, event aware fidelity driven sampling, and active fusion. A brief introduction to each of these fields will be presented. Also included will be a description of the second generation NIMS prototype node currently deployed at the James San Jacinto Mountain Reserve in Idyllwild California and some of the current field biology experiments being undertaken with this technologypublicNetworked Infomechanical Systems (NIMS)articlelocaloai:escholarship.org:ark:/13030/qt5gt3m03c2011-07-02T10:41:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/5gt3m03cY.-C. TongauthorG. Pottieauthor2008-01-01publicStatistics and Data PracticesThe Marginal Utility of Cooperation in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt22j1w3x82011-07-02T10:39:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/22j1w3x8Koushanfar, FarinazauthorKiyavash, NegarauthorPotkonjak, Miodragauthor2006-10-22Missing data is unavoidable in sensor networks due to sensor faults, communication malfunctioning and malicious attacks. There is a very little insight in missing data causes and statistical and pattern properties of missing data in collected data streams. To address this problem, we utilize interacting-particle model that takes into account both patterns of missing data at individual sensor data streams as well as the correlation between occurrence of missing data at other sensor data streams. The model can be used in algorithms and protocols for energy efficient data collection and other tasks in presence of missing data.We use statistical intersensor models for predicting the readings of different sensors. As a driver application, we address the problem of energy efficient sensing by adaptively coordinating the sleep schedules of sensor nodes while we guarantee that values of nodes in the sleep mode can be recovered from the awake nodes within a user’s specified error bound and probability of missing data at awake nodes is less than a given threshold. The sleeping coordination is addressed by creating the maximal number of subgroups of disjoint nodes, each of whose data is sufficient to recover the data of the entire network in presence of missing data. On simulated and actually collected data for temperature and humidity sensors in Intel Berkeley Lab, we show that by using sleeping coordination that considers missing data, we reduce the typical 40% missing data rate of traditional sleeping techniques to less than 7%.publicMultiscaled Actuated Sensingstatistical analysiswireless sensor networkscommunication malfunctioninghumidity sensorsinteracting particle-based modelmalicious attacksmissing datasensor data collectionsensor faultssensor networksleep schedulessleeping coordinationstatistical intersensor modelstemperature sensorsInteracting Particle-based Model for Missing Data in Sensor Networks: Foundations and Applicationsarticlelocaloai:escholarship.org:ark:/13030/qt0nw798m92011-07-02T10:38:21Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0nw798m9Gnawali, OmprakashauthorYarvis, Mark DauthorHeidemann, JohnauthorGovindan, Rameshauthor2004-05-05Unpredictable and heterogeneous links in a wireless sensor network require techniques to avoid low delivery rate and high delivery cost. Three commonly used techniques to help discover high quality paths include (1) link-layer retransmission, (2) blacklisting bad links, and (3) end-to-end routing metrics. Using simulation and testbed experiments, we present the rst systematic exploration of the tradeoffs of combinations of these approaches, quantifying the effects of each of these three techniques. We identify several key results: One is that per-hop retransmissions (ARQ) is a necessary addition to any other mechanism if reliable data delivery is a goal. Additional interactions between the services are more subtle. First, in a multihop network, either blacklisting or reliability metrics like ETX can provide consistent high-reliability paths when added to ARQ. Second, at higher deployment densities, blacklisting has a lower routing overhead than ETX. But at lower densities, blacklisting becomes less stable as the network partitions. These results are consistent across both simulation and testbed experiments. We conclude that ETX with retransmissions is the best choice in general, but that blacklisting may be worth considering at higher densities, either with or without ETX.publicSystemsInteraction of Retransmission, Blacklisting, and Routing Metrics for Reliability in Sensor Network Routingarticlelocaloai:escholarship.org:ark:/13030/qt1s5775ht2011-07-02T10:38:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1s5775htWallis, J CauthorMilojevic, StasaauthorBorgman, C LauthorSandoval, William Aauthor2006-11-01The seemingly simple task of reusing data for science education relies on the presence of scientific data, scientists willing to share, infrastructure to provide access, and mechanisms to share between the two disparate communities of scientists and science students. What makes sharing between scientists and science students a special case of data sharing, is that all of the implicit knowledge attending the data must pass along this same vector. Our work at the Center for Embedded Networked Sensing studying aspects of this data reuse problem has shown us a rough outline of how the future of this data sharing will look. Our approach is to start from the prospective of the scientists, looking for opportunities to support scientific research, and then leveraging the data for reuse by education. The investment needed to capture high quality scientific data necessitates the consideration of reuse by the general population as well as other interested scientific parties.publicThe Special Case of Scientific Data Sharing with Educationarticlelocaloai:escholarship.org:ark:/13030/qt0r31h0vp2011-07-02T10:37:50Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/0r31h0vpNithya RamanathanauthorKevin ChangauthorRahul KapurauthorLewis GirodauthorEddie KohlerauthorDeborah Estrinauthor2005-01-01Being embedded in the physical world, sensor networks present a wide range of bugs and misbehavior qualitatively different than those in most distributed systems. Unfortunately, due to resource constraints, programmers must investigate these bugs with only limited visibility into application behavior. We need a new approach. This paper presents the design and evaluation of Sympathy, a tool for detecting and debugging failures in pre- and post-deployment sensor networks. Sympathy consists of mechanisms for reporting generic system and application metrics; mechanisms for identifying conditions based on these metrics; a simple debugging algorithm to detect failures based on the conditions; and a system for logging metrics and events in their spatiotemporal context. We describe Sympathy and evaluate its performance through fault injection, and by debugging an active application, ESS, in simulation, emulation, and deployment. We show that Sympathy"s analysis and choice of metrics help programmers detect failures and correlate events into the root causes of bugs.publicA Debugging System for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt6gm8q0pc2011-07-02T10:37:40Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6gm8q0pcM. A. BatalinauthorM. RahimiauthorY.YuauthorD.LiuauthorA.KansalauthorG.S. SukhatmeauthorW.J. KaiserauthorM.HansenauthorG. J. PottieauthorM. SrivastavaauthorD. Estrinauthor2004-01-01publicTowards Event-Aware Adaptive Sampling Using Static and Mobile Nodesarticlelocaloai:escholarship.org:ark:/13030/qt8823t1n22011-07-02T10:37:23Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8823t1n2Ahmadian, ShaunauthorKo, TeresaauthorCoe, SharonauthorHamilton, M PauthorRahimi, MohammadauthorSoatto, StefanoauthorEstrin, Dauthor2007-11-07We present a scalable end-to-end system for vision-based monitoring of a biological phenomenon. Our system enables automated analysis of thousands of images, where manual processing would be infeasible. We automate the analysis of raw imaging data using statistics that are tailored to the task of interest, the study of avian behavior during nesting cycles. The system uses simple image statistics (features) as the low-level representation to be fed to generic classifiers and final inferences exploit the temporal and spatial consistencies. Our testbed achieves bird detection accuracy of 82%, and egg counting accuracy of 84%, allowing inference of avian nesting stage with accuracy within a day. Our results demonstrate the challenges and potential of using imagers as biological sensors. An exploration of system performance under varying image resolution and frame rate suggest that an in situ adaptive vision system is technically feasible.publicMultiscaled Actuated SensingHeartbeat of a Nest: Using Imagers as Biological Sensorsarticlelocaloai:escholarship.org:ark:/13030/qt6sj003r42011-07-02T10:37:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6sj003r4Mani SrivastavaauthorMark HansenauthorJeff BurkeauthorAndrew ParkerauthorSasank ReddyauthorGaneriwal SaurabhauthorMark AllmanauthorVern PaxsonauthorDeborah Estrinauthor2006-01-01The creation over the past decade of unanticipated applications of the Internet, such as web services, peer-to-peer file sharing, networked gaming, podcasting, and voice telephony, is resulting in a recent rethinking of the core Internet infrastructure and the original architecture choices. In this project however we propose to go beyond reacting to these applications that have already emerged, and proactively consider the network architecture implications of a new class of applications involving embedded sensing technology as it moves from scientific, engineering, defense, and industrial contexts to the wider personal, social and urban contexts. Today, applications are emerging which draw on sensed information about people, objects, and physical spaces. These applications enable new kinds of social exchange: By collecting, processing, sharing, and visualizing this information, they can offer us new and unexpected views of our communities. They require new algorithms and software mechanisms because unlike scientific applications of distributed sensing, a single system is widely distributed, intermittently connected, and privately administered; and unlike traditional Internet applications the physical inputs are critical to the behavior.publicWireless Urban Sensing Systemsarticlelocaloai:escholarship.org:ark:/13030/qt1n2445p62011-07-02T10:37:03Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1n2445p6Amarjeet SinghauthorMaxim BatalinauthorVictor ChenauthorMichael StealeyauthorBrett JordanauthorJason FisherauthorThomas HarmonauthorMark HansenauthorWilliam Kaiserauthor2006-01-01Distributed, high-density spatiotemporal observations are proposed for answering many river-related questions, including those pertaining to hydraulics and multi-dimensional river modeling, geomorphology, sediment transport and riparian habitat restoration. We present here a case study of an autonomous, high-resolution robotic spatial mapping of cross-sectional velocity and salt concentration in a river basin. Several experiments for analyzing the spatial and temporal trends at multiple cross-sections of the San Joaquin River were performed during the campaign from August 21-25, 2006. Preliminary analysis from these experiments illustrating the range of investigations is presented. Lessons learned during the campaign are discussed to provide useful insights for similar robotic investigations in aquatic environments.publicAutonomous Robotic Sensing Experiments at San Joaquin Riverarticlelocaloai:escholarship.org:ark:/13030/qt9dw389zb2011-07-02T10:36:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9dw389zbKevin ChangauthorJohn HicksauthorMartin LukacauthorDustin McIntireauthorTom SchoellhammerauthorThanos StathopoulosauthorKaren WeeksauthorRichard Guyauthor2006-01-01The Systems Infrastructure team assembles, tests, and provides complete sensor network solutions containing both exploratory and hardened components, from high-level applications and analysis tools, down to hardware at the sensor platform level. Recent significant progress is seen in SensorBase and ESS2 at the database and application levels; in disruption-tolerant data delivery and system control software; in auto-ranging and self-configuration acoustic platform software and in energy harvesting (heliomote) and low-power energy-aware microserver platforms (LEAP).publicSYS 5: Systems Infrastructurearticlelocaloai:escholarship.org:ark:/13030/qt89x2398c2011-07-02T10:36:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/89x2398cThomas HarmonauthorJason FisherauthorYeonjeong ParkauthorNithya RamanathanauthorJennifer JayauthorWilliam KaiserauthorSteve MargulisauthorJose SaezauthorAlexander RatkoauthorJuyoul KimauthorMohammad RahimiauthorJohn HicksauthorLaura BalzanoauthorNaim BusekauthorJohn EwartauthorSarah RothenbergauthorMichael StealeyauthorSandra Rocio Villamizar AmayaauthorChris ButlerauthorChe-Chua WuauthorMani SrivastavaauthorDeborah Estrinauthor2006-01-01publicCON 0: CENS Contaminant Transport Observation and Management (Contam) Research Overviewarticlelocaloai:escholarship.org:ark:/13030/qt89t2v2622011-07-02T10:35:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/89t2v262Hanbiao WangauthorKung YaoauthorDeborah Estrinauthor2004-01-01To facilitate the study of the wireless sensor network for demanding acoustic monitoring of long distance sources, we recently have also started working on the development of a new generation of wireless acoustic sensor network platform using the Stargate nodes. The 400 MHz PXA-255 XScale processor and the 64 MB SDRAM provide the Stargate platform a decent processing capability. The VX Pocket 440 sound card with four external microphones are attached to each Stargate node through the PCMCIA slot for acoustic data acquisition. We use highly-sensitive external microphones with low self-noise. The VXPocket 440 sound card supports data sampling up to 48 KHz in 24 bits. Each Stargate node also has a flash interface to connect a 802.11 card for wireless communication. The Stargate-based platform is for the acoustic monitoring of woodpeckers in the James Reserve and the like.publicStargate-based Acoustic Sensor Platformarticlelocaloai:escholarship.org:ark:/13030/qt1hc5b9rs2011-07-02T10:35:48Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/1hc5b9rsC.E. ChenauthorF. LorenzelliauthorR.E. HudsonauthorK. Yaoauthor2006-01-01This paper deals with the problem of estimating the Direction-of-Arrivals (DOAs) of multiple wideband sources using an array of sensors. While a variety of estimation techniques have been proposed in the literature, the Maximum-Likelihood (ML) DOA estimator has been shown to have superior performance under many challenging environments. In this paper, we propose a novel implementation for ML DOA estimator based on the Cross-Entropy (CE) method. Simulation result shows the CE algorithm converges to the CRB in all scenarios within several iterations and the convergence speed is insensitive to the coherence of sources compared to the Alternating Projection (AP) method.publicAcoustic Source DOA Estimation using the Cross-Entropy Method (SYS 14)articlelocaloai:escholarship.org:ark:/13030/qt3fk811r72011-07-02T10:35:36Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/3fk811r7Ben TitzerauthorJens Palsbergauthor2004-01-01Simulation can be an important step in the development of software for wireless sensor networks and has been the subject of intense research in the past decade. While most previous efforts in simulating wireless sensor networks have focused on protocol level issues utilizing models of the software implementation, a significant challenge remains in precisely measuring time dependent properties such as radio channel utilization. One promising approach, first demonstrated by ATEMU, is to simulate the behavior of sensor network programs at the machine code level in a cycle accurate way, but poor performance has so far limited its scalability. In this paper we present Avrora, a cycle accurate instruction level sensor network simulator which scales to networks of up to 10,000 nodes and performs as much as 20 times faster than previous simulators with equivalent accuracy, handling as many as 25 nodes in real time. We show how an event queue can enable efficient instruction level simulation of microcontroller programs and allow the hidden parallelism in fine grained sensor network simulations to be extracted, once two core synchronization problems are identified and solved. Avrora s ability to measure detailed time critical phenomena can shed new light on design issues for large scale sensor networks.publicAvrora Scalable Simulation of Sensor Networks with Precise Timingarticlelocaloai:escholarship.org:ark:/13030/qt4sn741ns2011-07-02T10:31:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/4sn741nsShilton, KatieauthorBurke, Jeffrey AauthorEstrin, DauthorGovindan, RameshauthorHansen, MarkauthorKang, JerryauthorMun, Minauthor2009-01-01For decades, the Codes of Fair Information Practice have served as a model for data privacy, protecting personal information collected by governments and corporations. But professional data management standards such as the Codes of Fair Information Practice do not take into account a world of distributed data collection, nor the realities of data mining and easy, almost uncontrolled, dissemination. Emerging models of information gathering create an environment where recording devices, deployed by individuals rather than organizations, disrupt expected flows of information in both public and private spaces. We suggest expanding the Codes of Fair Information Practice to protect privacy in this new data reality. An adapted understanding of the Codes of Fair Information Practice can promote individuals’ engagement with their own data, and apply not only to governments and corporations, but software developers creating the data collection programs of the 21st century. To support user participation in regulating sharing and disclosure, we discuss three foundational design principles: primacy of participants, data legibility, and engagement of participants throughout the data life cycle. We also discuss social changes that will need to accompany these design principles, including engagement of groups and appeal to the public sphere, increasing transparency of services through voluntary or regulated labeling, and securing a legal privilege for raw location data.publicUrban Sensingprivacymobile sensingDesigning the Personal Data Stream: Enabling Participatory Privacy in Mobile Personal Sensingarticlelocaloai:escholarship.org:ark:/13030/qt6r96j4rb2011-07-02T09:03:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/6r96j4rbTitzer, B LauthorJoshua AuerbachauthorDavid F. BaconauthorPalsberg, Jauthor2007-01-01Embedded systems pose unique challenges to Java application developers and virtual machine designers. Chief among these challenges is the memory footprint of both the virtual machine and the applications that run within it. With the rapidly increasing set of features provided by the Java language, virtual machine designers are often forced to build custom implementations that make various tradeoffs between the footprint of the virtual machine and the subset of the Java language and class libraries that are supported. In this paper, we present the ExoVM, a system in which an application is initialized in a fully featured virtual machine, and then the code, data, and virtual machine features necessary to execute it are packaged into a binary image. Key to this process is feature analysis, a technique for computing the reachable code and data of a Java program and its implementation inside the VM simultaneously. The ExoVM reduces the need to develop customized embedded virtual machines by reusing a single VM infrastructure and automatically eliding the implementation of unused Java features on a per-program basis. We present a constraint-based instantiation of the analysis technique, an implementation in IBM's J9 Java VM, experiments evaluating our technique for the EEMBC benchmark suite, and some discussion of the individual costs of some of Java's features. Our evaluation shows that our system can reduce the non-heap memory allocation of the virtual machine by as much as 75%. We discuss VM and language design decisions that our work shows are important in targeting embedded systems, supporting the long-term goal of a common VM infrastructure spanning from motes to large servers.publicSystemsVM designVM modularitydead code eliminationembedded systemsfeature analysispersistencepre-initializationstatic analysisstatic compilationThe ExoVM System for Automatic VM and Application Reductionarticlelocaloai:escholarship.org:ark:/13030/qt8qf7v8kv2011-07-01T07:50:11Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8qf7v8kvMichael HamiltonauthorEric GrahamauthorDeborah EstrinauthorPhil RundelauthorMichael AllenauthorBill KaiserauthorBill SwensonauthorMichael WimbrowauthorMichael TaggartauthorVanessa Rivera Del RioauthorEric Yuenauthor2005-01-01The goal of this integrated and cross-campus project is to sense the environment from the leaf to the landscape level. Aspects of the project include, but are not limited to: (1) NIMS and fixed-camera technologies that allow the real-time and automated observation of plant phenological events: leaf flushes, flowering, herbivore attack, and pollination and flower-visitation events. (2) Embedded micro-sensors that include light sensors sensitive to photosynthetic photon flux (PPF; 400-700 nm wavelength) installed on leaf surfaces indicate leaf- and plant-level responses to changes in light conditions, sap flow sensors that measure the velocity at which the transpiration stream flows by the dissipation of heat within a branch, and micrometeorological sensors that monitor conditions that change the driving force for transpiration and affect water balance on a plant- and landscape-level. (3) Minirhizotron tubes enable the direct measurement of root growth and allow for the estimations of microbial activity in the soil.publicTER2: Multiscale Multimodal Embedded Sensing of Plant Phenology and Physiologyarticlelocaloai:escholarship.org:ark:/13030/qt6cm2g31x2011-07-01T07:49:05Z am 3u Center for Embedded Network SensingVol. 24, no. 2 (Jan. 2007) 151-159eScholarship, University of Californiahttps://escholarship.org/uc/item/6cm2g31xHarmon, T CauthorAmbrose, Richard FauthorGilbert, RobertauthorFisher, JasonauthorStealey, MichaelauthorKaiser, W Jauthor2007-01-01Increasing demands on water supplies, along with concerns about non-point source pollution, and water quality–based ecological factors all point to the need for observing stream flow perturbations and pollutant discharges at higher resolution than has been practical until now. This work presents a rapidly deployable Networked Infomechanical System (NIMS RD) technology for observing spatiotemporal variability in hydraulic and chemical properties across stream channels. NIMS RD is comprised of two supporting towers and a suspension cable delivering power and Internet connectivity for controlling and actuating the tram-like NIMS unit. The NIMS unit is capable of raising and lowering a payload of sensors, allowing a preprogrammed or data-actuated adaptive scan to be completed across a stream channel. In this paper, NIMS RD is demonstrated in two relevant cases: (1) elucidating spatiotemporal variations in nutrients and other biologically significant stream constituents in Medea Creek, a small urban stream in Southern California; and (2) using high-resolution synoptic sampling of steady velocity and salinity distributions across the San Joaquin River in Central California to provide quantitative salt load estimates. For Medea Creek, temperature and specific conductivity (SC) exhibited varying cross-sectional patterns throughout each of three 24 hour scans carried out over three summer months. Both temperature and SC displayed repeating sinusoidal diel fluctuations independent of the spatial variation. For each of the months the cross-sectional variation was less during the late nighttime and morning hours than during the afternoon and early nighttime hours. For the San Joaquin River, high-resolution velocity distributions from NIMS RD were successfully reproduced in separate deployments and quantitatively matched stage-based volumetric flow rates at the site. The product of the velocity and associated SC distributions yielded total salt load estimates similar to previously reported values, but no basis for direct comparison was available.publicContaminant Transportstreamriverhydraulicswater qualityconfluencesalinitytemperaturerobotic samplingHigh-Resolution River Hydraulic and Water Quality Characterization Using Rapidly Deployable Networked Infomechanical Systems (NIMS RD)articlelocaloai:escholarship.org:ark:/13030/qt9xz2k8402011-03-23T00:30:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9xz2k840Gummadi, RamakrishnaauthorLi, XinauthorGovindan, RameshauthorShahabi, CyrusauthorHong, Weiauthor2005-05-05Recent sensor networks research has produced a class of data storage and query processing techniques called Data-Centric Storage that leverages locality-preserving distributed indexes like DIM, DIFS, and GHT to efficiently answer multi-dimensional range and rangeaggregate queries. These distributed indexes offer a rich design space of a) logical decompositions of sensor relation schema into indexes, as well as b) physical mappings of these indexes onto sensors. In this poster, we explore this space for energy-efficient data organizations (logical and physical mappings of tuples and attributes to sensor nodes) and devise purely local query optimization techniques for processing queries that span such decomposed relations. We propose four design techniques: (a) fully decomposing the base sensor relation into distinct sub-relations, (b) spatially partitioning these sub-relations across the sensornet, (c) localized query planning and optimization to find fully decentralized optimal join orders, and (d) locally caching join results. Together, these optimizations reduce the overall network energy consumption by 4 times or more when compared against the standard single multidimensional distributed index on a variety of synthetic query workloads simulated over both synthetic and real-world datasets. We validate the feasibility of our approach by implementing a functional prototype of our data organizer and query processor on Mica2 motes and observing comparable message cost savings.publicSensor NetworksData-Centric StorageDCSData OrganizationQuery OptimizationCachingEnergy-Efficient Data Organization and Query Processing in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt9xc0f5662011-03-23T00:30:03Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9xc0f566Chen, Chiao-EnauthorAli, Andreas MauthorLorenzelli, F.authorHudson, Ralph E.authorYao, Kauthor2006-05-14We propose a novel algorithm employing particle filters for acoustic source tracking in a reverberant environment. By incorporating the likelihood function computed through Approximate Maximum-Likelihood (AML) method, the proposed algorithm is applicable to wideband sources and can be implemented for multiple sources tracking. Both computer simulation and experimental results show the effectiveness of the proposed algorithm.publicMultiscaled Actuated Sensingacoustic signal processingmaximum likelihood estimationparticle filtering (numerical methods)approximate maximum-likelihood methodmoving acoustic source localizationmoving acoustic source trackingmultiple sources trackingparticle filteringreverberant roomwideband sourcesParticle Filtering Approach to Localization and Tracking of a Moving Acoustic Source in a Reverberant Roomarticlelocaloai:escholarship.org:ark:/13030/qt9x70f3w02011-03-23T00:30:02Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9x70f3w0Samanta, VidyutauthorRyder, JasonauthorBurke, Jeffrey AauthorEstrin, DauthorWagmister, Fabianauthor2007-10-10We are deploying a metropolitan scale Wi-Fi mesh network near downtown Los Angeles to support the design and development of a data-centric network-fabric for urban participatory sensing. Participatory sensing employs software and network technology to enable people’s everyday mobile devices to act as credible sensors of the natural, built, and cultural environments. Current research focuses on how to make it easy and secure for both the public and professional users to define sensing ‘campaigns,’ recruit participants to collect data, to help ‘make a case’ with data they collect, and digitally publish the results. To further research in this area, our architecture will enable embedding network–attested location and time context in sensor readings. The network will also provide a research framework for developing policy-based privacy, and related security mechanisms for participatory sensing.publicMetropolitan Wi-Fi Research Networkarticlelocaloai:escholarship.org:ark:/13030/qt9t0758gb2011-03-23T00:29:57Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9t0758gbMcIntire, DustinauthorAu, LawrenceauthorChow, TimothyauthorDantu, KarthikauthorShah, MansiauthorStathopoulos, ThanosauthorSukhatme, GauravauthorKaiser, W Jauthor2007-10-10A broad range of embedded networked sensor (ENS) systems for critical environmental monitoring applications now require complex, high peak power dissipating sensor devices, as well as on-demand high performance computing and high bandwidth communication. Embedded computing demands for these new platforms include support for computationally intensive image and signal processing as well as optimization and statistical computing. To meet these new requirements while maintaining critical support for low energy operation, a new multiprocessor node hardware and software architecture, Low Power Energy Aware Processing (LEAP), has been developed. The LEAP architecture integrates fine-grained energy dissipation monitoring and sophisticated power control scheduling for all subsystems including sensor subsystems. The LEAP2 platform is a second generation LEAP system with even higher resolution energy monitoring as well as the unique ability to do per process and per application energy profiling via a dedicated high performance ASIC. This poster will demonstrate the hardware platform capabilities as well as the energy-aware software currently available for LEAP2.publicSystemsThe Low Power Energy Aware Processing (LEAP) Embedded Networked Sensor Systemarticlelocaloai:escholarship.org:ark:/13030/qt9s4541mh2011-03-23T00:29:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9s4541mhKim, KarenauthorUehara, WesauthorEstrin, Dauthor2007-10-10publicEducationCENS Education Overviewarticlelocaloai:escholarship.org:ark:/13030/qt9r57j3k82011-03-23T00:29:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9r57j3k8Ganesan, DeepakauthorGreenstein, BenauthorEstrin, DauthorHeidemann, JohnauthorGovindan, Rameshauthor2007-05-05Wireless sensor networks enable dense sensing of the environment, offering unprecedented opportunities for observing the physical world. This article addresses two key challenges in wireless sensor networks: in-network storage and distributed search. The need for these techniques arises from the inability to provide persistent, centralized storage and querying in many sensor networks. Centralized storage requires multihop transmission of sensor data to Internet gateways which can quickly drain battery-operated nodes.Constructing a storage and search system that satisfies the requirements of data-rich scientific applications is a daunting task for many reasons: (a) the data requirements may be large compared to available storage and communication capacity of resource-constrained nodes, (b) user requirements are diverse and range from identification and collection of interesting event signatures to obtaining a deeper understanding of long-term trends and anomalies in the sensor events, and (c) many applications are in new domains where a priori information may not be available to reduce these requirements.This article describes a lossy, gracefully degrading storage model. We believe that such a model is necessary and sufficient for many scientific applications since it supports both progressive data collection for interesting events as well as long-term in-network storage for in-network querying and processing. Our system demonstrates the use of in-network wavelet-based summarization and progressive aging of summaries in support of long-term querying in storage and communication-constrained networks. We evaluate the performance of our linux implementation and show that it achieves: (a) low communication overhead for multiresolution summarization, (b) highly efficient drill-down search over such summaries, and (c) efficient use of network storage capacity through load-balancing and progressive aging of summaries.publicwireless sensor networksdata storagewavelet processingmultiresolution storagedata agingdrill-down queryMulti-Resolution Storage and Search in Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt9mj6b80x2011-03-23T00:29:43Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9mj6b80xHarmon, ThomasauthorJay, JennyauthorSaez, JoseauthorKaiser, WilliamauthorMargulis, SteveauthorRat'ko, AlexanderauthorLin, Chu-ChinauthorFisher, JasonauthorWu, Che-ChuanauthorButler, ChristopherauthorBuchanan, DolvinauthorByrn, GaryauthorPai, HenryauthorHavens, KellyauthorHermosillo, MarvinauthorRananathan, NithyaauthorBarnes, PatrickauthorVillamizar Amaya, SandraauthorStathopoulos, ThanosauthorLin, TiffanyauthorPark, Yeonjeongauthor2009-05-12The contaminant assessment and management (or “Contam”) research area focuses on developing and implementing embedded networked sensing (ENS) technology to support this new observational strategy in the context of mass and energy distributions and fluxes across a range of temporal and synoptic scales. The specific areas of interest for Contam include soils, groundwater, and riparian systems. The Contam application domain is unique relative to the other three CENS applications in that it is often concerned with enabling adaptive management of environmental problems through engineered responses triggered by ENS observations. Example applications include improving our understanding of river metabolism in relation to adjacent and upstream land management practices, creating closed-loop feedback-control systems for conserving irrigation water and avoiding excessive nitrogen application in agricultural systems, delineating nutrient fluxes between groundwater and surface water, and rapid identification of coastal pollutants.publicContaminant TransportAn Overview of CENS Contaminant Transport Observation and Management Researcharticlelocaloai:escholarship.org:ark:/13030/qt9mf6x4sx2011-03-23T00:29:42Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9mf6x4sxFeng, JessicaauthorGirod, LewisauthorPotkonjak, Miodragauthor2007-04-10We have developed statistical error modeling techniques for acoustic signal detection-based ranging measurements in the framework of wireless ad-hoc sensor networks (WASNs). The models are used as the basis for solving the location discovery problem in sensor networks. We first demonstrate that the major difficulty in location discovery is how to treat errors by proving the location discovery in presence of noisy measurements is a NP-complete problem, even in onedimensional space. Consequently, we formulate the location discovery as an instance of nonlinear function minimization that optimizes each of the empirically derived statistical error models. The minimization problem is then solved using a conjugate gradient-based nonlinear function optimization solver.We validate the efficiency of the approach by conducting comprehensive experiments on both deployed and simulated WASNs. The results indicate that the statistical model-based approach significantly improves the location accuracy compared with the approaches using the traditional optimization objectives. In addition, the localized version of our location discovery algorithm is capable of finding competitive solutions using significantly lower communication cost.publicMultiscaled Actuated Sensingstatistical error modelinglocation discoveryLocation Discovery Using Data-Driven Statistical Error Modelingarticlelocaloai:escholarship.org:ark:/13030/qt9fq9r7jn2011-03-23T00:29:31Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9fq9r7jnBandari, RojaauthorPottie, Gregoryauthor2007-10-10Acoustic source localization often requires the transmission of full received waveforms to a fusion center. Using these waveforms the location of a source can be estimated by different methods such as Beamforming, MUSIC, or AML. In either of these cases, a large number or bits is communicated to the fusion center. When communication has to be done in a wireless manner, a considerable amount of energy is expended and where power is not readily available, this can result in shortening the lifetime of the system. We are interested in investigating how much accuracy is lost by reducing the number of bits transmitted by each sensor. This poster demostrates a study of the tradeoffs between localization performance and number of bits transmitted. A few cases were simulated where sensors have a capability of measuring signal power and can transmit only one bit in one case and two bits in another case.publicCommunication vs. Performance in Source Localizationarticlelocaloai:escholarship.org:ark:/13030/qt9fh6p3ws2011-03-23T00:29:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9fh6p3wsStauffer, BethauthorCetinic, IvonaauthorDarjany, LindsayauthorBai, XuemeiauthorCaron, Davidauthor2007-10-10King Harbor in the City of Redondo Beach, California was the site of massive fish kills during 2005 following intense and prolonged red tide events. Weekly monitoring since early 2006 revealed the presence of an abundant and diverse community of potentially harmful dinoflagellate and raphidophyte species in the harbor with highly heterogeneous spatial and temporal distributions. Vertical migration and photoacclimation of dinoflagellates and raphidophytes were investigated as mechanisms for dealing with changing light levels in the King Harbor marina over a 24-hour cycle on 19-20 June 2007. PAR, CTD, chlorophyll fluorescence, dissolved oxygen concentrations, active chlorophyll fluorescence, backscattering, and light absorption and attenuation data were measured every four hours using sensor arrays. Discrete water samples were analyzed for pigment concentrations, particulate and dissolved inorganic nutrients, and phytoplankton community composition using both microscopical and molecular techniques. The overall phytoplankton community composition changed significantly during the 24-hour cycle, and the depth of the chlorophyll maximum moved from shallow waters to deeper depths, and possibly all the way to the sediment interface, during the evening hours. These data suggest a high degree of small-scale heterogeneity in vertical distribution of harmful algal populations and provide important insights into mechanisms that impact community composition within red tide assemblages in King Harbor.publicInvestigations of Fine-scale Diel Migration of Phytoplankton Populations in King Harbor, Redondo Beacharticlelocaloai:escholarship.org:ark:/13030/qt96t4z8xd2011-03-23T00:29:11Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/96t4z8xdKohler, MonicaauthorHeaton, Thomas H.authorGovindan, RameshauthorDavis, PaulauthorEstrin, D.author2006-10-16Ideally both spectral and time domain data could be used to compute the total building response and to make predic- tions of damage patterns based on various input scenarios. The combination of frequency change information coupled with that provided by wavefield properties can pinpoint the time and location of damage more accurately, especially for densely instru- mented structures such as the 17-story UCLA Factor building. The 72-sensor embedded seismic array in the Factor building, recording continuous waveforms at 500 Hz, makes it possible to observe subtle changes in dynamic characteristics between pairs of floors and to relate the measurements to system properties such as changes in stiffness due to a column failure. The high dy- namic range of the 24-bit digitizers allows both strong motions and ambient vibrations to be recorded with reasonable sig- nal-to-noise ratios. Temporary decreases in frequencies of Factor building modes of vibration have been correlated with moder- ate-to-strong shaking, and spectral amplitudes of ambient vibrations have clear daily and weekly patterns that correlate with working hours, wind speeds, and non-seismic vibrations. Waveform data from the Factor array are also being used in comparison with finite element calculations for predictive damage behavior. A three-dimensional model of the Factor building has been developed based on structural drawings. Observed displacements for 20 small and moderate, local and regional earthquakes were used to compute the impulse response functions of the building by deconvolving the subbasement records as a proxy for the free field. It can be shown that small but significant changes in the travel times, mode shapes, and frequencies are observed in the simulation results for strong ground shaking and for modifications to the structural model for hypothesized damage patterns such as broken welds on a particular floor. Wireless untethered devices whose design is guided by data analysis and simulations such as these can significantly increase the spatial resolution of structural response to earthquakes. A Mica-Z mote network controlled by Wisden software that monitors a local area such as a building is being assembled and tested. The software system addresses some of the challenges associated with high sample rates and limited radio bandwidth, yet allows structural data acquisition from a relatively large network of wireless sensors.publicSeismicWireless sensorsStructural monitoringDamage detectionWave propagationUsing Embedded Wired and Wireless Seismic Networks in the Moment-Resisting Steel Frame Factor Building for Damage Identificationarticlelocaloai:escholarship.org:ark:/13030/qt96j1w5jc2011-03-23T00:29:10Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/96j1w5jcKansal, AmanauthorSrivastava, Mani B.author2005-05-05publicDistributed Energy Harvesting for Energy Neutral Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt94n787sj2011-03-23T00:29:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/94n787sjSingh, AmarjeetauthorBatalin, MaximauthorStealey, MichaelauthorChen, VictorauthorHansen, MarkauthorHarmon, T CauthorSukhatme, GauravauthorKaiser, W Jauthor2007-07-09This paper reports the first application of iterative experimental design methodology for high spatiotemporal resolution characterization of river and lake aquatic systems performed using mobile robot sensing systems. Both applications involve dynamic phenomena spread over large spatial domain: 1) Characterization of contaminant concentration and flow at the confluence of two major rivers displaying dynamics due to flow of the water; and 2) Characterization of rapidly evolving biological processes such as phytoplankton dynamics in a lake system. We describe the development and application of a new general purpose method for mobile robot sensing in such environments - Iterative experiment Design for Environmental Applications (IDEA). IDEA introduces in-field adaptation of mobile robotic sensing system. Analysis of the complex spatial and temporal structures associated with each observed environment is presented. Detailed characterization of the observed environment using IDEA methodology is used as an informed prior to improve the performance of the existing adaptive experimental design approaches for mobile robotic systems - stratified adaptive sampling and hierarchical non-stationary Gaussian Processes.publicMultiscaled Actuated SensingMobile Robot Sensing for Environmental Applicationsarticlelocaloai:escholarship.org:ark:/13030/qt9350j5392011-03-23T00:29:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9350j539Kim, KarenauthorUehara, WesleyauthorEstrin, DeborahauthorAllen, MichaelauthorBorgman, ChristineauthorCarter-LaFlamme, AmberauthorBurke, JeffauthorCook, MelissaauthorGriffis, KathyauthorGuy, RichardauthorHamilton, MichaelauthorHansen, MarkauthorHanusa, RobertauthorHarmon, TomauthorJay, JenniferauthorKaiser, WilliamauthorLau, AndrewauthorLee, ChristineauthorLui, KaisingauthorMartinez, KristinaauthorMehta, AnandauthorMisa, KimauthorNavarro, JuanauthorPottie, GregauthorRyu, SunaauthorSrivastava, ManiauthorSandoval, WilliamauthorSax, LindaauthorWallis, JillianauthorWallace, JohnauthorWise, JoeauthorWong, Jackieauthor2009-05-12publicEducationEducation Overviewarticlelocaloai:escholarship.org:ark:/13030/qt92w6g3md2011-03-23T00:29:00Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/92w6g3mdKothari, NupurauthorMillstein, ToddauthorGovindan, Rameshauthor2009-05-12The most common programming languages and platforms for sensor networks foster a low-level programming style. This design provides fine-grained control over the underlying sensor devices, which is critical given their severe resource constraints. However, this design also makes programs difficult to understand, maintain, and debug. In this work, we describe an approach to automatically recover the high-level system logic from such low-level programs, along with an instantiation of the approach for nesC programs running on top of the TinyOS operating system. We adapt the technique of symbolic execution from the program analysis community to handle the event-driven nature of TinyOS, providing a generic component for approximating the behavior of a sensor network application or system component. We then employ a form of predicate abstraction on the resulting information to automatically produce a finite state machine representation of the component. We have used our tool, called FSMGen, to automatically produce compact and fairly accurate state machines for several TinyOS applications and protocols. We illustrate how this high-level program representation can be used to aid programmer understanding, error detection, and program validation.publicSystemsDeriving State Machines from TinyOS programs using Symbolic Executionarticlelocaloai:escholarship.org:ark:/13030/qt92q6c9xp2011-03-23T00:28:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/92q6c9xpAli, Andreas MauthorAsgari, ShadnazauthorCollier, Travis ColbyauthorAllen, Michael F.authorGirod, LewisauthorHudson, R. E.authorYao, KauthorBlumstein, DanielauthorTaylor, C Eauthor2007-10-10We present the use of the AML algorithm formulated for isotropic and non-isotrophic 3D acoustic source localization. Then we will discuss the recent efforts on the modifications of the wireless-linked acoustic sensing nodes, called ENSBoxes, to achieve accurate node self-localization and array orientations, all crucially needed for the accurate localization of acoustic source(s). We will summarize extensive field measured data collected at RMBL, Colorado, as well as at UCLA, to confirm the proper operations of the system.public2D and 3D Acoustic Source Localization Using the AML Algorithm and ENSBox Nodesarticlelocaloai:escholarship.org:ark:/13030/qt92m8w4m12011-03-23T00:28:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/92m8w4m1Agapie, EauthorHoward, EauthorRyder, JasonauthorSteiner, AauthorLam, DauthorRosario, RauthorModschein, AauthorHouston, DauthorBurke, Jeffrey AauthorHansen, MarkauthorEstrin, Dauthor2007-10-10This project asks “what if we had a constantly updated assessment of our own personal impact on the environment?” It explores how models of environmental exposure and impact can be refined with GPS location data to show us the effects of lifestyle choices that we make every day—their contribution to the environment that we live in with our children, parents, and neighbors. This is the personal, real-time equivalent of government-mandated Environmental Impact Reports and Health Impact Assessments, which document the impact of construction and public works projects on our environment and health.publicPersonal Environment Impact Reportarticlelocaloai:escholarship.org:ark:/13030/qt915743c52011-03-23T00:28:55Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/915743c5Kim, DohyunauthorGoldberg, Ira BauthorGlickman, MichaelauthorJudy, Jack Wauthor2007-10-10A sensitive and miniaturized amperometric nitrate (NO3-) sensor for groundwater monitoring was designed, fabricated, and tested. The thin-film microelectrodes were patterned on the silicon substrate with microfabrication techniques. The sensor shows very promising performance, compared to commercial nitrate sensors. A low detection limit of 4 ?M and wide dynamic range of 10 mM with excellent linearity (r2=0.99) are achieved and yet sensor is in a small form factor (4×4×3 cm). Many efforts have been being made to improve the sensor reliability and to realize stand-alone field measurements. Reference electrode was treated with polyurethane coating. An automated sample-handling and sensor calibration system was studied. A miniaturized potentiostat with built-in pumps and valves controller have also been made. In order to overcome short life-time of the thin-film sensing electrode, a palm-sized sensor that consists of Plexiglass housing, macro-scale electrodes, and microfluidic channels have been newly developed. The interference from common ions in groundwater was characterized and major interferents are Sr+, Ca2+, and PO¬43-. An ion specific membrane is employed in the sensor to minimize interference, and selectivity of the sensor is currently being analyzed.publicA High-performance Micromachined Amperometric Nitrate Sensor for Environmental Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt9155b0f12011-03-23T00:28:54Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/9155b0f1Rahimi, MohammedauthorShah, HardikauthorSukhatme, GauravauthorHeidemann, JohnauthorEstrin, Dauthor2003-09-14We study the feasibility of extending the lifetime of a wireless sensor network by exploiting mobility. In our system, a small percentage of network nodes are autonomously mobile, allowing them to move in search of energy, recharge, and delivery energy to immobile, energy-depleted nodes. We term this approach energy harvesting. We characterize the problem of uneven energy consumption, suggest energy harvesting as a possible solution, and provide a simple analytical framework to evaluate energy consumption and our scheme. Data from initial feasibility experiments using energy harvesting show promising results.publicSystemsmobile robotspower consumptionsolar cellswireless sensor networksenergy consumptionenergy depleted nodesenergy harvestingenergy searchmobile wireless sensor networknetwork nodesStudying the Feasibility of Energy Harvesting in a Mobile Sensor Networkarticlelocaloai:escholarship.org:ark:/13030/qt90r880ch2011-03-23T00:28:53Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/90r880chBorgman, C LauthorWallis, J CauthorEnyedy, Nauthor2006-09-17As data become scientific capital, digital libraries of data become more valuable. To build good tools and services, it is necessary to understand scientists’ data practices. We report on an exploratory study of habitat ecologists and other participants in the Center for Embedded Networked Sensing. These scientists are more willing to share data already published than data that they plan to publish, and are more willing to share data from instruments than hand-collected data. Policy issues include responsibility to provide clean and reliable data, concerns for liability and misappropriation of data, ways to handle sensitive data about human subjects arising from technical studies, control of data, and rights of authorship. We address the implications of these findings for tools and architecture in support of digital data libraries.publicStatistics and Data PracticesBuilding Digital Libraries for Scientific Data: An Exploratory Study of Data Pratices in Habitat Ecologyarticlelocaloai:escholarship.org:ark:/13030/qt90j149pp2011-03-23T00:28:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/90j149ppShilton, KatieauthorBurke, Jeffrey AauthorEstrin, DauthorHansen, MarkauthorSrivastava, Maniauthor2008-04-21Urban sensing systems that use mobile phones enable individuals and communities to collect and share data with unprecedented speed, accuracy and granularity. But employing mobile handsets as sensor nodes poses new challenges for privacy, data security, and ethics. To address these challenges, CENS is developing design principles based upon understanding privacy regulation as a participatory process. This paper briefly reviews related literature and introduces the concept of participatory privacy regulation. PPR reframes negotiations of social context as an important part of participation in sensing-supported research. It engages participants in ethical decision-making and the meaningful negotiation of personal boundaries and identities. We use PPR to establish a set of design principles based on our application drivers.publicUrban SensingUrban sensingprivacyethicsparticipatory designparticipatory researchParticipatory Privacy in Urban Sensingarticlelocaloai:escholarship.org:ark:/13030/qt8wb432382011-03-23T00:28:42Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8wb43238Ryder, JasonauthorLongstaff, BrentauthorReddy, SasankauthorEstrin, Dauthor2009-05-01An important tool for evaluating the health of patients who suffer from mobility-affecting chronic diseases such as MS, Parkinson’s, and Muscular Dystrophy is assessment of how much they walk. Ambulation is a mobility monitoring system that uses Android and Nokia N95 mobile phones to automatically detect the user’s mobility mode. The user’s only required interaction with the phone is turning it on and keeping it with him/her throughout the day, with the intention that it could be used as his/her everyday mobile phone for voice, data, and other applications, while Ambulation runs in the background. The phone uploads the collected mobility and location information to a server and a secure, intuitive web-based visualization of the data is available to the user and any family, friends or caregivers whom they authorize, allowing them to identify trends in their mobility and measure progress over time and in response to varying treatments.publicUrban Sensingambulationsmartphonecampaignrhealthcare technologyAmbulation: a tool for monitoring mobility patterns over time using mobile phonesarticlelocaloai:escholarship.org:ark:/13030/qt8vq444gh2011-03-23T00:28:39Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8vq444ghYu, YanauthorEstrin, DauthorGovindan, RameshauthorRahimi, Mohammedauthor2004-05-05Sensor network research is still in its infancy. Few real systems are deployed and little experimental data from sensor networks is available to test proposed protocol designs. Due to lack of experimental data and sophisticated models derived from such data, most data processing algorithms from the sensor network literature are evaluated with data generated from simple parametric models.We identify a few widely-studied classes of problems that are potentially sensitive to data input: Statistics estimation of the field data; Data compression; and Field estimation. We use them as examples to investigate the dependency of algorithm performance on data.For each class of problem, given the selected problem and algorithm instance, we systematically study how the algorithm performance varies across a range of data input. We also demonstrate how different data input can change the algorithm performance dramatically, the performance comparison between two algorithms may even change depending on the different data inputs.In the end, we propose our synthetic data generation framework and recommend evaluating algorithms across a wide range of data input.publicUsing More Realistic Data Models to Evaluate Sensor Network Data Processing Algorithmsarticlelocaloai:escholarship.org:ark:/13030/qt8v1239d82011-03-23T00:28:36Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8v1239d8Mayernik, MatthewauthorMayoral, KeithauthorLukac, MartinauthorHansen, MarkauthorBorgman, Christineauthor2009-05-12CENS researchers are developing flexible wireless sensing technologies that can be used in a variety of scientific and social applications. These technologies produce data that often have value to both the immediate research questions and to longer-term studies of longitudinal phenomena. CENS sensing systems are being deployed in many different real-world settings. Managing sensor deployments and the resulting data can be difficult. This poster outlines our work in developing tools to help CENS researchers conduct deployments and manage the resulting data, specifically the CENS Deployment Center, Sensorbase, and the deployment webpages created for the Seismic Deployment in Peru. The CENS Deployment Center (CENSDC) is a web-based repository for CENS deployment information. The CENSDC provides a central location for researchers to document deployment activities through the creation of pre-deployment plans and post-deployment feedback/notes. By allowing users to describe their deployment experiences, including lessons learned, troubleshooting techniques, and guidance for future deployments, the CENSDC attempts to capture the tacit knowledge about equipment setups, deployment locations, and field preparations that play a critical role in data collection techniques. Sensorbase is a database for CENS sensor collected data. Users can set up automated data uploads into Sensorbase from remote wifi enabled nodes deployed in the field, enabling researchers to monitor and manage their data remotely. Sensorbase can also generate email alerts when user-defined conditional changes in data occur, eliminating the need to search through the collected data to see that something is wrong (or right) with the deployment. Also, a programmatic approach to doing some of the features previously allowed only in the web user interface has been implemented so that sensors in the field can do more without human interaction. Finally, Sensorbase allows users to designate all or portions of their data to be shared with other researchers. The Peru deployment is a joint UCLA and Caltech project to study seismic activity along the South American subduction zone. Along with the seismic data, the seismic team is collecting various kinds of technical data to measure the health of the seismic stations, as well as of the wireless networks that connect them to each other and to the internet. These measures help the seismic team to identify problems as they arise. We created a number of interfaces that display network health metrics for the installed stations to enable members of the seismic team to view the current status of the wireless links across the transect, and helping them to be more responsive to emerging problems. These tools facilitate more efficient sensor deployments by allowing researchers to discover problems with data in real-time, identify and describe the problems, and annotate the solutions for future deployments. Through this process, the resulting data should be of higher quality in the short term, and more easily used and reused in the long term.publicStatistics and Data PracticesTools for Dynamic Deployment and Data Managementarticlelocaloai:escholarship.org:ark:/13030/qt8v01m8wj2011-03-23T00:28:35Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8v01m8wjJoki, AugustauthorBurke, Jeffrey AauthorEstrin, Dauthor2007-10-26Participatory sensing takes advantage of the pervasive nature of mobile phones to collect data about the urban environment using the available sensors. Campaignr makes collecting this data as simple as a few button pushes. It provides access to the sensors in a robust and flexible way that hides the complexities of the mobile embedded phone environment. This paper describes the design choices and provides some numerical evaluation of Campaignr. Campaignr has been and is being actively used as the data collection method for many research pro jects, both internally and externally.publicurbanparticipatorycampaignCampaignr: A Framework for Participatory Data Collection on Mobile Phonesarticlelocaloai:escholarship.org:ark:/13030/qt8sv2t5xc2011-03-23T00:28:30Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8sv2t5xcKaiser, W JauthorSukhatme, Gaurav S.author2007-10-10publicAn Overview of Multiscale Actuation and Sensingarticlelocaloai:escholarship.org:ark:/13030/qt8r93r4v22011-03-23T00:28:28Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8r93r4v2Kobele, Gregory MauthorRiggle, JasonauthorCollier, Travis CauthorLee, YoosookauthorLin, YingauthorYao, YuanauthorTaylor, C EauthorStabler, E Pauthor2003-05-05publicMultiscaled Actuated SensingGrounding as Learningarticlelocaloai:escholarship.org:ark:/13030/qt8qx229h52011-03-23T00:28:26Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8qx229h5Skolnik, DerekauthorLukac, MartinauthorNaik, Vinayak SauthorKaiser, W JauthorKohler, MonicaauthorGovindan, RameshauthorDavis, PaulauthorEstrin, DauthorStubailo, IgorauthorIrving, Samauthor2007-10-10CENS research related to developing and implementing structural health monitoring (SHM) systems is advancing on two distinct but related fronts; ShakeNet, a portable wireless sensor network for instrumenting civil structures and SHMnet, for monitoring of tall buildings in Los Angeles. SHM is the process of assessing the state of health (e.g., damage) of instrumented structures from measurements. The goal of SHM is to improve safety and reliability of infrastructure systems by detecting damage before it reaches a critical state, or to allow rapid post-event assessment. The primary objective of the SHMnet research is the development of a robust SHM system along with the associated hardware and software, using tall and special buildings in Los Angeles as a testbed. To manage this large-scale, multi-disciplinary goal, the work tasks are divided into several key focus areas, each with specific objectives, including the development of; a robust wireless Data Acquisition (DAQ) toolbox suitable for rapid urban deployments, a suite of state-of-the-art sensors for monitoring key structural responses including an innovative laser/photodiode for directly measuring interstory drift, and probabilistic post-event assessment algorithms based on experimental motion-damage relationships. A confluence of events, namely the local boom in tall building design and construction, the LA-DBS instrumentation requirements for tall buildings, the technology and experience of CENS and nees@UCLA, coupled with the active participation of key industrial partners, provides the synergy required to enable the proposed research.ShakeNet is a vibration sensor network designed for use in civil structures such as buildings and bridges for system identification and for identifying potential locations of damage due to earthquake motions. ShakeNet can also be used in test structures loaded to failure to characterize damage signals in waveform data such as those produced by moment-frame weld fractures. ShakeNet is a multi-tier wireless sensing system of 75 wireless nodes that can be rapidly deployed by 2-3 people on, for example, multiple floors of a large building. It will be designed to collect structural vibration measurements for up to a week from each node within the network. This portable system can be used to instrument large structures within hours immediately after an earthquake. Significant aftershocks of even moderate-size earthquakes occur for up to a week after the earthquake. What makes ShakeNet application-realistic is careful attention to the design of its data-acquisition hardware, the ShakeBoard. The ShakeBoard is a 24-bit high resolution acceleration data acquisition system that uses commercial low-noise MEMS accelerometers and conforms to specifications currently being established by the US Geological Survey for their Advanced National Seismic System (ANSS). ShakeNet’s software subsystem will be built upon Tenet; programmable wireless sensing software designed for multi-tier sensor networks. The strength of ShakeNet lies in the planned field tests in order to make it application-realistic. Future tests of ShakeNet, pending project funding, include deployments in moment-frame steel and reinforced concrete buildings, a bridge, and a dam near the San Andreas Fault.publicDevelopments on the CENS Structural Health Monitoring Frontarticlelocaloai:escholarship.org:ark:/13030/qt8qn830cq2011-03-23T00:28:25Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8qn830cqSilva, FabioauthorGraham, EricauthorRundel, PhilauthorDeSchon, AnnetteauthorYe, WeiauthorBhatt, SpundunauthorPradkin, Yuriauthor2007-10-10The scientific application being addressed at the Stunt Ranch, a 310-acre reserve in the Santa Monica Mountains, is a long-term investigation of the influence of the 2006-07 Southern California drought conditions on the water relations of important chaparral shrub and tree species that differ in their depth of rooting. Rainfall over this past hydrologic year in Southern California has been less than 25% of normal, making it the driest year on record. Measurements will be made using sap flow sensors to continuously monitor the flow of water through the xylem system of replicated stems of four species to compare their access to soil moisture with plant water stress. Core measurements of air temperature, relative humidity, solar irradiance, rainfall, and soil moisture will be monitored continuously at the same site. The project utilizes a flexible satellite Sensornet gateway adapting new Compact RIO technologies under development for NEON.publicSupporting Ecological Research With a Flexible Satellite Sensornet Gatewayarticlelocaloai:escholarship.org:ark:/13030/qt8q18c9m82011-03-23T00:28:22Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8q18c9m8Ramanathan, NithyaauthorKohler, EddieauthorGirod, LewisauthorEstrin, Dauthor2004-05-05publicSystemsSympathy: A Debugging System for Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt8mb6468v2011-03-23T00:28:17Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8mb6468vWong, J LauthorMegerian, SeapahnauthorPotkonjak, Miodragauthor2006-10-22Efficient and complete data collection is one of the most important tasks in wireless ad-hoc sensor networks. Additionally, the collection of the full data set should be performed in the most resource efficient way, thus prolonging the battery lifetime of the network. We introduce a new approach for energy efficient data collection through the use of staggered sampling. Staggered sampling means that at each sampling moment (epoch) only a small percentage of sensors collect (sample) data. The proposed approach leverages on statistical relationships between samples taken from different sensors and/or at different epochs for the prediction of the non-sampled sensor data.The main goal of the approach is to ensure complete collection of data during a periodic cycle while minimizing the number of sensor readings collected at any point in time. Complete data collection is confirmed by ensuring that each sensor is either sampled at each epoch or the data sample can be accurately recovered though model prediction of the sampled sensors. The proposed approach consists of two main phases. First, efficient modeling of the prediction relationship between two sensors using kernel smoothing over different time lags is performed. Second, the selection of epochs at which each sensor is to sample the data is determined. A 0-1 integer linear programming formulation is used to address this NP-complete assignment problem optimally on relatively large instances. We demonstrate the effectiveness of the approach on traces from actually deployed networks for sensor of two modalities: temperature and humidity.publicMultiscaled Actuated SensingStaggered Sampling for Efficient Data Collectionarticlelocaloai:escholarship.org:ark:/13030/qt8kv8h9672011-03-23T00:28:16Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8kv8h967Pon, RichardauthorBatalin, MaximauthorChen, VictorauthorKansal, AmanauthorLiu, DuoauthorRahimi, MohammedauthorShirachi, LisaauthorSomasundara, ArunauthorYu, YanauthorHansen, MarkauthorKaiser, W JauthorSrivastava, Mani BauthorSukhatme, GauravauthorEstrin, Dauthor2005-05-05Distributed embedded sensor networks are now being successfully deployed in environmental monitoring of natural phenomena as well as for applications in commerce and physical security. While substantial progress in sensor network performance has appeared, new challenges have also emerged as these systems have been deployed in the natural environment. First, in order to achieve minimum sensing fidelity performance, the rapid spatiotemporal variation of environmental phenomena requires impractical deployment densities. The presence of obstacles in the environment introduces sensing uncertainty and degrades the performance of sensor fusion systems in particular for the many new applications of image sensing. The physical obstacles encountered by sensing may be circumvented by a new mobile sensing method or Networked Infomechanical Systems (NIMS). NIMS integrates distributed, embedded sensing and computing systems with infrastructure-supported mobility. NIMS now includes coordinated mobility methods that exploits adaptive articulation of sensor perspective and location as well as management of sensor population to provide the greatest certainty in sensor fusion results. The architecture, applications, and implementation of NIMS will be discussed here. In addition, results of environmentally-adaptive sampling, and direct measurement of sensing uncertainty will be described.publicCoordinated Static and Mobile Sensing for Environmental Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt8kh101pm2011-03-23T00:28:15Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8kh101pmBorgman, C LauthorWallis, J CauthorMayernik, Matthew SauthorPepe, Albertoauthor2007-06-18New technologies for scientific research are producing a deluge of data that is overwhelming traditional tools for data capture, analysis, storage, and access. We report on a study of scientific practices associated with dynamic deployments of embedded sensor networks to identify requirements for data digital libraries. As part of continuing research on scientific data management, we interviewed 22 participants in 5 environmental science projects to identify data types and uses, stages in their data life cycle, and requirements for digital library architecture. We found that scientists need continuous access to their data from the time that field experiments are designed through final analysis and publication, thus reflecting a broader notion of “digital library.” Six categories of requirements are discussed: the ability to obtain and maintain data in the field, verify data in the field, document data context for subsequent interpretation, integrate data from multiple sources, analyze data, and preserve data. Three digital library efforts currently underway within the Center for Embedded Networked Sensing are addressing these requirements, with the goal of a tightly coupled interoperable framework that, in turn, will be a component of cyberinfrastructure for science.publicStatistics and Data Practicesscientific datauser-centered designfunctional requirements
analysisnetworked sensingdata delugedata capturedata usedata preservationDrowning in Data: Digital Library Architecture to Support Scientific of Embedded Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt8jp308rg2011-03-23T00:28:11Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8jp308rgKim, YounghunauthorSchmid, ThomasauthorCharbiwala, ZainulauthorSrivastava, ManiauthorBurke, Jeffauthor2009-05-12The average person is currently unaware of the real-time energy consumption for the different household appliances that he uses. At best, he can observe the monthly or bi-monthly bill indicating the total power consumption of all the appliances combined. This makes it difficult to improve the consumption efficiency, since there is no visibility in the data that he can access. We believe that real-time appliance level monitoring is necessary to allow residents to manage their energy consumption efficiently. However, monitoring end-point level power consumption is difficult to impossible with current technologies because expensive sensors, or professionally installation is necessary. In addition, device aesthetic and the inherent intrusiveness of direct in-line sensors to measure the energy usage at every end-point complicate such a system installation. Since appliances emit measurable signals when they are consuming resources, we argue that less-invasive sensors can be used for inferring real-time resource consumption. However, indirect sensors cannot be calibrated during manufacturing because of varying ambient conditions. Thus, the main challenge becomes to provide a method that autonomously calibrates the sensors. We seek to develop an easy and self-configurable monitoring system for very fine grained resource monitoring in residential spaces.publicSystemsToward Resource Efficient Homes: From Measurements to Sustainable Choicesarticlelocaloai:escholarship.org:ark:/13030/qt8h58f66w2011-03-23T00:28:09Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8h58f66wPoduri, SameeraauthorSukhatme, Gaurav Sauthor2007-10-10Coalescence is the problem of isolated mobile robots independently searching for peers with the goal of forming a single connected network. This paper analyzes coalescence time for a worst-case scenario where the robots do not have any knowledge about the environment or positions of other robots and perform independent, memory less search. Using the random direction mobility model, we show that coalescence time has an exponential distribution which is a function of the number of robots, speed, communication range, and size of the domain. Further, as the number of robots (N) increases, coalescence time decreases as O(1/sqrt(N)) and Omega(log(N)/N). Simulations validate our analysis and also suggest that the lower bound is tight.publicCoalescence for Mobile Sensor Networksarticlelocaloai:escholarship.org:ark:/13030/qt8fq0v0p82011-03-23T00:28:05Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8fq0v0p8Sabet, LeylaauthorHo, Chih-Mingauthor2007-10-10With the confocal Laser induced fluorescent sensor developed in our lab concentrations as low as 5.9 fM can be detected. We will work with Professor Caron at USC and Professor Tai at Caltech to detect Amnestic shellfish poisoning (ASP) caused by ingestion of contaminated shellfish by Domoic Acid (DA) causes death both in human beings and animals when the contamination is higher than 20 ?g (64 ?Mole) of DA per gram of shellfish tissue. DA is produced by a number of algae, including microalgae of the genus Pseudo-nitzschia, and it is accumulated by shellfish filter feeding during Pseudo-nitzschia blooms. Competitive ELISA is used for DA detection down to 0.2 ng/mL. The detection limit not low enough, the confocal Laser induced fluorescent sensor is going to be used to detect lower concentrations of DA. In our sensor optics are used to define a very small detection volume. In this method, molecules of interest are labeled with fluorophores. A droplet of sample is added to the sensor. The target molecules which are conjugated with fluorescent molecules will move in and out of the detection volume by diffusion and Brownian motion. A photon burst is observed when the molecule passes the detection volume and the number of peaks per unit of time indicates the concentration of sample under study. Using the pinhole for confocal microscopy will reduce the background noise coming from the reflection and spurious fluorescence background and going to lower concentration down to single molecules will be made possible. The molecule under study can be easily changed with this sensor.publicOptical Detection of Domoic Acid: a major marine algal toxinarticlelocaloai:escholarship.org:ark:/13030/qt8d48d2k22011-03-23T00:28:01Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8d48d2k2Pepe, AlbertoauthorBorgman, C Lauthor2007-10-10At CENS, various efforts aimed at the preservation and dissemination of scientific material have emerged over time, resulting in data being collected in three main repository systems: 1), CENSDC, a database service that provides access to CENS deployments in a centralized web location, 2) Sensorbase.org, a data warehouse for raw sensor data and 3) CDL eScholarship Repository, a digital library service for articles, technical reports and similar scholarly material. We anticipate forthcoming data repositories to include, among others, a directory of CENS people and a sensor software library. Despite the heterogeneity of this content, we believe that these information resources are all building blocks of the same scholarly production chain. With this concept in mind, we are designing a framework that allows the creation, discovery, ingest and publication of aggregated information resources via simple web services.publicAggregating Resources to Facilitate Discovery and Re-Use of Sensor Dataarticlelocaloai:escholarship.org:ark:/13030/qt8cr1m9222011-03-23T00:27:59Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/8cr1m922Lin, DavidauthorBarbieri, AlanauthorMitra, Urbashiauthor2007-10-10Research in the field of underwater sensor networks exists from the need for scientific data collection, pollution monitoring, offshore oil exploration, tsunami warnings, ocean mapping, and tactical surveillance without human assistance. Aided with acoustic communication systems, autonomous underwater vehicles (AUVs) can work along with fixed nodes to enhance the capablities of sensor networks. With channel estimation algorithms, AUVs can detect connectivity loss and position sensors to self-configure for optimal network efficiency. However, one of the biggest challenges to underwater networks is multipath fading, where the reflection and scattering from the bottom and surface of the ocean result in severe intersymbol interference (ISI) of transmitted signals. Secondly, sound absorption loss increases with the increase in frequency, dramatically limiting the bandwidth available. Orthogonal frequency division multiplexing (OFDM) is proposed as a possible method of communication, by transmitting signals over multiple subcarriers simultaneously.publicSingle Channel Estimation Algorithm for Acoustic OFDM Communication Systemsarticlelocaloai:escholarship.org:ark:/13030/qt895068dn2011-03-23T00:27:53Z am 3u Center for Embedded Network SensingVol. 4487 (May. 2007) 995-1001eScholarship, University of Californiahttps://escholarship.org/uc/item/895068dnCaron, David A.authorDas, AbhimanyuauthorDhariwal, AmitauthorGolubchik, LeanaauthorGovindan, RameshauthorKempe, DavidauthorOberg, CarlauthorSharma, AbhishekauthorStauffer, BethauthorSukhatme, Gauravauthorzhang, binauthor2007-05-27Observing systems facilitate scientific studies by instrumenting the real world and collecting corresponding measurements, with the aim of detecting and tracking phenomena of interest. Our AMBROSia project focuses on a class of observing systems which are embedded into the environment, consist of stationary and mobile sensors, and react to collected observations by reconfiguring the system and adapting which observations are collected next. In this paper, we report on recent research directions and corresponding results in the context of AMBROSia.publicStatistics and Data PracticesAMBROSia: An Autonomous Model-Based Reactive Observing Systemarticlelocaloai:escholarship.org:ark:/13030/qt88b146bk2011-03-23T00:27:52Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/88b146bkSingh, DigvijayauthorKaiser, W Jauthor2010-05-26This Technical Report provides a review of a new embedded computing platform enabling research, education and training, and product development based on the Intel Atom processor architecture. This introduces a dramatic advance in the capability for direct characterization of energy and power dissipation in embedded computing platforms and the associated capabilities for optimization of performance and energy. This report includes development, usage, and example operation and results with platform applications in mobile computing, distributed sensing, network routing, and wireless access point implementation. In each case, Atom LEAP is intended to provide both a reference design and a high throughput, easily implemented solution with an unprecedented advance in the capability for characterizing energy usage at a level of computing task and operating system detail substantially superior to prior methods.publicSystemsVLSI and circuits, Embedded and Hardware Systemsenergy efficient computingembedded computingembedded networked sensingThe Atom LEAP Platform For Energy-Efficient Embedded Computingarticlelocaloai:escholarship.org:ark:/13030/qt8773s6xx2011-03-23T00:27:49Z am 3u Center for Embedded Network SensingVol. 24, no. 11–12 (Aug. 2007) 969-989eScholarship, University of Californiahttps://escholarship.org/uc/item/8773s6xxSingh, AmarjeetauthorBatalin, MaximauthorStealey, MichaelauthorZhang, BinauthorDhariwal, AmitauthorStauffer, BethauthorMoorthi, StefanieauthorOberg, Carlauthorde Menezes Pereira, Arvind AntonioauthorChen, VictorauthorLam, YeungauthorCaron, DavidauthorHansen, MarkauthorKaiser, W JauthorSukhatme, Gauravauthor2007-08-22Large-scale environmental sensing, e.g., understanding microbial processes in an aquatic ecosystem, requires coordination across a multidisciplinary team of experts working closely with a robotic sensing and sampling system. We describe a human-robot team that conducted an aquatic sampling campaign in Lake Fulmor, San Jacinto Mountains Reserve, California during three consecutive site visits (May 9–11, June 19–22, and August 28–31, 2006). The goal of the campaign was to study the behavior of phytoplankton in the lake and their relationship to the underlying physical, chemical, and biological parameters. Phytoplankton form the largest source of oxygen and the foundation of the food web in most aquatic ecosystems. The reported campaign consisted of three system deployments spanning four months. The robotic system consisted of two subsystems—NAMOS (networked aquatic microbial observing systems) comprised of a robotic boat and static buoys, and NIMS-RD (rapidly deployable networked infomechanical systems) comprised of an infrastructure-supported tethered robotic system capable of high-resolution sampling in a two-dimensional cross section (vertical plane) of the lake. The multidisciplinary human team consisted of 25 investigators from robotics, computer science, engineering, biology, and statistics.We describe the lake profiling campaign requirements, the robotic systems assisted by a human team to perform high fidelity sampling, and the sensing devices used during the campaign to observe several environmental parameters. We discuss measures taken to ensure system robustness and quality of the collected data. Finally, we present an analysis of the data collected by iteratively adapting our experiment design to the observations in the sampled environment. We conclude with the plans for future deployments.publicMultiscaled Actuated SensingHuman Assisted Robotic Team Campaigns for Aquatic Monitoringarticlelocaloai:escholarship.org:ark:/13030/qt86h0z2782011-03-23T00:27:46Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/86h0z278Mascia, Jeffrey M.authorLee, Juo-YuauthorNikzad, NimaauthorRahimi, MohammedauthorSrivastava, Mani B.author2007-10-10While cameras have the potential to enable many applications in sensor networks, to be effective they must first be externally calibrated. In prior systems, cameras, identified by controllable light sources, utilized angular measurements amongst themselves to determine their relative positions and orientations. However, the typical camera’s narrow field of view makes such systems susceptible to failures in the presence of occlusions or non-ideal configurations. Actuation-assistance helps to overcome such issues by essentially broadening each camera’s view. In this paper we discuss and implement a prototype system that uses actuation to aid in the external calibration of camera networks. We evaluate our system using simulations and a testbed of MicaZ nodes, equipped with Cyclops camera modules mounted on custom pan-tilt platforms. Our results show that actuation-assistance can dramatically reduce node density requirements.publicActuation–assisted Calibration of Distributed Camera Networksarticlelocaloai:escholarship.org:ark:/13030/qt85f6w6sv2011-03-23T00:27:45Z am 3u Center for Embedded Network SensingVol. 150, no. 4 (Apr. 2010) 640-649eScholarship, University of Californiahttps://escholarship.org/uc/item/85f6w6svGraham, EricauthorLam, YeungauthorYuen, Ericauthor2010-04-01The characterization of the solar radiation environment under a forest canopy is important for both understanding temperature-dependent biological processes and validating energy balance models. A modified sinusoidal model of soil heat conductivity was used to estimate subsurface temperature and heat flux from the uneven but periodic solar heating of the soil surface due to sun flecks from a forest canopy. Using a mobile sensor platform with an infrared thermometer along an 11 m transect, a sunfleck model of soil surface temperature was tested using soil surface temperature maxima, air temperatures, and photodiodes placed on the soil surface to measure sunflecks. A pan-tilt-zoom digital camera on a 10 m tower above the site was then used to capture a time series of panoramic images of sunflecks reflected from the soil surface and to scale the sunfleck temperature model to a wide area. Finally, this image-based model of surface temperatures was combined with the modified sinusoidal model for heat conduction to estimate soil subsurface temperatures and heat flux over a wide area due to sunflecks from a forest canopy.publicTerrestrialMultiscaled Actuated SensingOther Plant Sciencessoiltemperaturedigital cameraForest understory soil temperatures and heat flux calculated using a Fourier model and scaled using a digital cameraarticlelocaloai:escholarship.org:ark:/13030/qt84w8b6b92011-03-23T00:27:43Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/84w8b6b9Dhariwal, Amitauthorzhang, binauthorde Menezes Pereira, Arvind AntonioauthorOberg, CarlauthorStauffer, BethauthorMoorthi, StefanieauthorCaron, David A.authorSukhatme, Gauravauthor2006-06-01As part of our research, we have designed and developed sensor-actuated network for marine monitoring. The network consists of ten static buoy nodes and one mobile robotic boat for real-time in-situ measurements and analysis of chemical, physical and biologically pertinent phenomena governing the abundance of micro-organisms at relevant spatio-temporal scales. The goal of the network is to obtain high-resolution information on the spatial and temporal distribution of plankton assemblages in aquatic environments using the in situ presence afforded by the network, and to make possible network-enabled robotic sampling of hydrographic features of interest. This work constitutes advances in (1) real-time observing in aquatic ecosystems and (2) sensor- actuated sampling for biological analysis.Ultimately such systems will be able to establish patterns in the sensed data, and use their mobility to adapt sample collection, a major step forward in the use of embedded networked sensing in aquatic ecosystems. The field work has demonstrated the basic functionality of the system. The data collected from the deployments revealed interesting spatio-temporal patterns of chlorophyll, and were useful to validate the design of the buoys and the boat. Static buoys provide low-resolution spatial sampling with high temporal resolution while a mobile robot boat provides high resolution spatial sampling with low temporal resolution.As part of the demonstration, we will be having our robotic boat at the event equipped with its sensor suite. The robotic boat is equipped with sensors for navigation, instrumentation for data gathering (temperature and chlorophyll) and can communicate with other entities in the environment over wireless 802.11b network and exchange information with them. As part of its capabilities, the boat can be hand-driven via an RC- controller or computer interface. Alternately, a user can specify a path for the boat in terms of gps locations to go to (in order) and the boat can than traverse the path autonomously and collect environmental data as it moves which can be streamed back and analyzed.We will also have on display our results from experiments with autonomous boat navigation and navigation improvements by running a simple EKF.publicAquaticNAMOS: Networked Aquatic Microbial Observing Systemarticlelocaloai:escholarship.org:ark:/13030/qt84v4f4zw2011-03-23T00:27:42Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/84v4f4zwKim, DonnieauthorPeterson, Nicolai MauthorKim, JoeauthorTabrizi, HalehauthorBurke, Jeffrey AauthorEstrin, Dauthor2007-10-10Human memory is a selective process where details are often lost, yet some types of research relies heavily on human memorization. Studies have shown that photographs help enhance the memory significantly. This study envisions to create a low-cost, mass-scale system using cell phones and to handle the massive amount of data that live image capture tends to implicate.publicScalable System Design for Assisted Recall: Leveraging everyday mobile phones and web servicesarticlelocaloai:escholarship.org:ark:/13030/qt84n2p36r2011-03-23T00:27:41Z am 3u eScholarship, University of Californiahttps://escholarship.org/uc/item/84n2p36rStathopoulos, ThanosauthorLukac, MartinauthorMcIntire, DustinauthorHeidemann, JohnauthorEstrin, DeborahauthorKaiser, William Jauthor2007-05-01Dual-radio, dual-processor nodes are an emerging class of Wireless Sensor Network devices that provide both low- energy operation as well as substantially increased computational performance and communication bandwidth for applications. In such systems, the secondary radio and processor operates with sufficiently low power that it may remain always vigilant, while the the main processor and primary, high-bandwidth radio remain off until triggered by the application. By exploiting the high energy efficiency of the main processor and primary radio along with proper usage, net operating energy benefits are enabled for applications. The secondary radio provides a constantly available multi-hop network, while paths in the primary network exist only when required. This paper describes a topology control mechanism for establishing an end-to-end path in a network of dual-radio nodes using the secondary radios as a control channel to selectively wake up nodes along the required end-to-end path. Using numerical models as well as testbed experimentation, we show that our proposed mechanism provides significant energy savings of more than 60% compared to alternative approaches, and that it incurs only moderately greater application latency.publicUrban SensingEnd-to-end Routing for Dual-Radio Sensor Networksarticlelocalmarc21:cens:500:671:eyJmaXJzdCI6NTAwLCJpbmNsdWRlIjpbIlBVQkxJU0hFRCIsIkVNQkFSR09FRCJdLCJvcmRlciI6IlVQREFURURfREVTQyIsImxhc3RJRCI6InF0ODRuMnAzNnIiLCJsYXN0RGF0ZSI6IjIwMTEtMDMtMjJUMTc6Mjc6NDEtMDc6MDAifQ