http://www.rssboard.org/rss-specification 720 https://escholarship.org/uc/citris/rss Recent eScholarship items from Center for Information Technology Research in the Interest of Society (CITRIS) Fri, 4 Sep 2026 09:20:16 +0000 https://escholarship.org/uc/item/29t4c67d This report explores the overall potential of blockchain’s use in the public sector and focuses on two use cases that have received less attention: blockchain-based digital identity and health records management systems for the homeless and other vulnerable populations in California. https://escholarship.org/uc/item/29t4c67d Fri, 23 Oct 2020 00:00:00 +0000 Crittenden, Camille Sistla, Maitreyi https://escholarship.org/uc/item/2j9596dp Blockchain in California: A Roadmap https://escholarship.org/uc/item/2j9596dp Tue, 7 Jul 2020 00:00:00 +0000 Crittenden, Camille https://escholarship.org/uc/item/9qq066hw Optimization of distributed power assets is a powerful tool that has the potential to assist utility efforts to ensure customer voltages are within pre-defined tolerances and to improve distribution system operations. While convex relaxations of Optimal Power Flow (OPF) problems have been proposed for both balanced and unbalanced networks, these approaches do not provide universal convexity guarantees and scale inefficiently as network size and the number of constraints increase. In balanced networks, a linearized model of power flow, the LinDistFlow model, has been successfully employed to solve approximate OPF problems quickly and with high degrees of accuracy. In this work, an extension of the LinDistFlow model is proposed for unbalanced distribution systems, and is subsequently used to formulate an approximate unbalanced OPF problem that uses VAR assets for voltage balancing and regulation. Simulation results on the IEEE 13 node test feeder demonstrate the ability of the unbalanced... https://escholarship.org/uc/item/9qq066hw Wed, 28 Jun 2017 00:00:00 +0000 Arnold, Daniel B Sankur, Michael Dobbe, Roel Brady, Kyle Callaway, Duncan S Von Meier, Alexandra https://escholarship.org/uc/item/974620tg <p>The goal of the Distributed Intelligent Automated Demand Response (DIADR) project at UC Berkeley is to reduce peak load of Sutardja Dai Hall by 30% while maintaining a healthy, comfortable, and productive environment for the occupants. The team consists of members fromSiemens, UC Berkeley and Lawrence Berkeley National Laboratory.</p><p>This paper describes the work in progress of achieving this goal in the office portion ofthe building given an overcooled building not fully commissioned, grossly oversized chillers, and problems isolating the nanofabrication laboratory. Most of the reduction comes from HVAC: increasing supply air and zone temperatures and reducing ventilation rates. Other reductionsinvolve dimming lights and turning off the tankless water heaters. Engaging the occupants of the building should provide further reduction. The web interface for the distributed load controller allows the prioritization of curtailable appliances and visualization of energy consumption.... https://escholarship.org/uc/item/974620tg Wed, 28 Jun 2017 00:00:00 +0000 Peffer, Therese, PhD Auslander, David Caramagno, Domenico Culler, David, PhD Jones, Tyler Krioukov, Andrew Sankur, Michael Taneja, Jay Trager, Jason Kiliccote, Sila Yin, Rongxin Lu, Yan Mukka, Prasad https://escholarship.org/uc/item/9390n4hc This paper describes a research project to develop a network of high-precision phasor measurement units, termed micro-synchrophasors or μPMUs, and explore the applications of μPMU data for electric power distribution systems. https://escholarship.org/uc/item/9390n4hc Wed, 28 Jun 2017 00:00:00 +0000 von Meier, Alexandra Culler, David McEachern, Alex Arghandeh, Reza https://escholarship.org/uc/item/8zq9x1qx This paper proposes a novel approach to detecting the topology of distribution networks based on the analysis of time series measurements. The analysis approach draws on data from high-precision phasor measurement units (PMUs or synchrophasors) for distribution systems. A key fact is that time-series data taken from a dynamic system show specific patterns regarding state transitions such as opening or closing switches, as a kind of signature from each topology change. The algorithm proposed here is based on the comparison of the actual signature of a recent state transition against a library of signatures derived from topology simulations. The IEEE 33-bus model is used for initial algorithm validation. https://escholarship.org/uc/item/8zq9x1qx Wed, 28 Jun 2017 00:00:00 +0000 von Meier, Alexandra Arghandeh, Reza Cavraro, Guido Barchi, Grazia https://escholarship.org/uc/item/846892fv The distribution grid is changing to become an active resource with complex modeling needs. The new active distribution grid will, within the next ten years, contain a complex mix of load, generation, storage and automated resources all operating with different objectives on different time scales from each other and requiring detailed analysis. Electrical analysis tools that are used to perform capacity and stability studies have been used for transmission system planning for many years. In these tools, the distribution grid was considered a load and its details and physical components were not modeled. The increase in measured data sources can be utilized for better modeling, but also control of distributed energy resources (DER). The utilization of these sources and advanced modeling tools will require data management, and knowledgeable users. Each of these measurement and modeling devices have accuracy constraints, which will ultimately define their future ability to be planned... https://escholarship.org/uc/item/846892fv Wed, 28 Jun 2017 00:00:00 +0000 von Meier, Alexandra Stewart, E. M. Kiliccote, Sila Arnold, Daniel Arghandeh, Reza https://escholarship.org/uc/item/7pd2h1rq Power flow analysis is one of the tools that is required in most of the distribution system studies. An important characteristic of distribution systems is the load unbalance in the phases and a three-phase power flow analysis is needed. In this paper, a three-phase linear power flow (3LPF) formulation is derived based on the fact that in a typical distribution system, voltage angles and magnitudes vary within relatively narrow boundaries. The accuracy of the proposed 3LPF is verified using several test cases. Potential applications of the proposed method are in distribution systems state estimation and volt-VAR optimization. https://escholarship.org/uc/item/7pd2h1rq Wed, 28 Jun 2017 00:00:00 +0000 Ahmadi, Hamed Martı´, José R von Meier, Alexandra https://escholarship.org/uc/item/7bz2n6jp Phasor Measurements for DistributionSystem Applications https://escholarship.org/uc/item/7bz2n6jp Wed, 28 Jun 2017 00:00:00 +0000 Stewart, Emma M von Meier, Alexandra https://escholarship.org/uc/item/79w4m753 With the unprecedented growth of renewable resources, electric vehicles, and controllable loads, power system has been incorporating increasing amount of unconventional generations and loads. As a consequence, significant dynamic and stochastic power flow are introduced into distribution network, requiring high resolution monitoring technology and agile decision support techniques for system diagnosis and control. In this paper, we discuss the application of micro-synchrophasor measurement unit (µPMU) for power distribution network monitoring, and we propose a novel data-driven method, namely Ensembles of Bundle Classifier (EBC), for event detection. The main idea is: multiple classifiers are learned each with a short slot of µPMU measurement generated by a single event. Then their decisions are combined with a “winner-takes-all” scheme. This framework naturally resolves the challenging issue of heterogeneity in the high resolution µPMU data, and significantly outperforms classic data-driven... https://escholarship.org/uc/item/79w4m753 Wed, 28 Jun 2017 00:00:00 +0000 Zhou, Yuxun Arghandeh, Reza Konstantakopoulos, Ioannis C Abdullah, Shayaan von Meier, Alexandra Spanos, Costas J https://escholarship.org/uc/item/61w8z66w <p>The introduction and deployment of cheap, high&nbsp;precision, high-sample-rate next-generation synchrophasors en-masse in both the transmission and distribution tier – while&nbsp;invaluable for event diagnosis, situational awareness and capacity&nbsp;planning – poses a problem for existing methods of phasor data&nbsp;analysis and storage.</p><p>Addressing this, we present the design andimplementation of a novel architecture for synchrophasor data&nbsp;analysis on distributed commodity hardware. At the core is a newfeature-rich timeseries store, BTrDB.</p><p>Capable of sustained writes&nbsp;and reads in excess of 16 million points per second per cluster&nbsp;node, advanced query functionality and highly efficient storage,&nbsp;this database enables novel analysis and visualization techniques.</p><p>Leveraging this, a distillate framework has been developed that&nbsp;enables agile development of scalable analysis pipelines with strict&nbsp;guarantees on result integrity despite... https://escholarship.org/uc/item/61w8z66w Wed, 28 Jun 2017 00:00:00 +0000 Andersen, Michael P Kumar, Sam Brooks, Connor von Meier, Alexandra, PhD Culler, David E, PhD https://escholarship.org/uc/item/5bw572t4 This paper proposes a data-driven approach to detect the switching actions and topology transitions in distribution networks. It is based on the real time analysis of time-series voltages measurements. The analysis approach draws on data from high-precision phasor measurement units (μPMUs or synchrophasors) for distribution networks. The key fact is that time-series measurement data taken from the distribution network has specific patterns representing state transitions such as topology changes. The proposed algorithm is based on comparison of actual voltage measurements with a library of signatures derived from the possible topologies simulation. The IEEE 33-bus model is used for the algorithm validation. https://escholarship.org/uc/item/5bw572t4 Wed, 28 Jun 2017 00:00:00 +0000 von Meier, Alexandra Poolla, Kameshwar Arghandeh, Reza Cavraro, Guido https://escholarship.org/uc/item/53w685k5 Power system has been incorporating increasing amount of unconventional generations and loads such as renewable resources, electric vehicles, and controllable loads. The induced short term and stochastic power flow requires high resolution monitoring technology and agile decision support techniques for system diagnosis and control. In this paper, we discuss the application of micro-phasor measurement unit (μPMU) for power distribution network monitoring, and study learning based data-driven methods for abnormal event detection. We first resolve the challenging problem of information representation for the multiple streams of high resolution μPMU data, by proposing a pooling-picking scheme. With that, a kernel Principle Component Analysis (kPCA) is adopted to build statistical models for nominal state and detect possible anomalies. To distinguish event types, we propose a novel discriminative method that only requires partial expert knowledge for training. Finally, our methods... https://escholarship.org/uc/item/53w685k5 Wed, 28 Jun 2017 00:00:00 +0000 Zhou, Yuxun Arghandeh, Reza Konstantakopoulos, Ioannis Abdullah, Shayaan von Meier, Alexandra Spanos, Costas J https://escholarship.org/uc/item/49d6x8tz Network topology in distribution networks is often unknown, because most switches are not equipped with measurement devices and communication links. However, knowledge about the actual topology is critical for safe and reliable grid operation. This paper proposes a voting-based topology detection method based on micro-synchrophasor measurements. The minimal difference between measured and calculated voltage angle or voltage magnitude, respectively, indicates the actual topology. Micro-synchrophasors or micro-Phasor Measurement Units (μPMU) are high-precision devices that can measure voltage angle differences on the order of ten millidegrees. This accuracy is important for distribution networks due to the smaller angle differences as compared to transmission networks. For this paper, a microgrid test bed is implemented in MATLAB with simulated measurements from μPMUs as well as SCADA measurement devices. The results show that topologies can be detected with high accuracy. Additionally,... https://escholarship.org/uc/item/49d6x8tz Wed, 28 Jun 2017 00:00:00 +0000 Arghandeh, Reza Gahr, Martin von Meier, Alexandra Cavraro, Guido Ruh, Monika Andersson, Göran https://escholarship.org/uc/item/2qv517b0 Information technology can increase energy efficiency by improving the control ofenergy-using devices and systems. Awareness of this potential is not new—ideas for applications of information technology for energy efficiency have been promoted for more than 20 years. Butmuch of the potential gain from the application of information technology has not yet been realized. In an earlier paper one of the authors discussed some reasons for the slow exploitation of information technology’s potential to increase energy efficiency. The earlier paper also suggested that a combination of new requirements for the operation of the electricity system andthe development of new technology could cause a rapid increase in the pace of adoption. In this paper we describe an application of these ideas to the operation of a commercial building. First, we review basic concepts with emphasis on an open software-architecture. Then we describe thecomponents of this open software-architecture and its ability,... https://escholarship.org/uc/item/2qv517b0 Wed, 28 Jun 2017 00:00:00 +0000 Blumstein, Carl Peffer, Therese https://escholarship.org/uc/item/2qf9607m This paper describes challenges for integrating high&nbsp;fidelity data with utility distribution operations. Two &nbsp;research&nbsp;projects are described microsynchrophasors (μPMU) and&nbsp;OpenPMU and explore the applications of data for electric&nbsp;power distribution systems. https://escholarship.org/uc/item/2qf9607m Wed, 28 Jun 2017 00:00:00 +0000 Stewart, Emma M Kiliccote, Sila Shand, C M McMorran, A W Arghandeh, Reza von Meier, Alexandra https://escholarship.org/uc/item/2cn5n4p9 In recent years, extreme weather events have severely affected the performance of the electric grid. Very large-scale events (VLSE) with potentially catastrophic impacts on the grid pose more than an inconvenience in today's electricity-driven lifestyle, and the frequency and severity of such events may continue to increase as a consequence of global climate change. This article summarizes the state of the art in leveraging distributed resources to improve resilience of the electric grid. It also highlights the technical questions that need to be addressed through additional research and development if the value of distributed resources is to be maximized. https://escholarship.org/uc/item/2cn5n4p9 Wed, 28 Jun 2017 00:00:00 +0000 Arghandeh, Reza Brown, Merwin Del Rosso, Alberto Ghatikar, Girish Stewart, Emma Vojdani, Ali von Meier, Alexandra https://escholarship.org/uc/item/1qc2b40h This paper proposes a novel phase identification method for distribution networks where phases can be severely unbalanced and insufficiently labeled. The analysis approach draws on data from high-precision phasor measurement units (micro-synchrophasors or uPMUs) for distribution systems. A key fact is that time-series voltage phasors taken from a distribution network show specific patterns regarding connected phases at measurement points. The algorithm is based on analyzing cross-correlations over voltage magnitudes along with phase angle differences on two candidate phases to be matched. If two measurement points are on the same phase, large positive voltage magnitude correlations and small voltage angle differences should be observed. The algorithm is initially validated using the IEEE 13-bus model, and subsequently with actual uPMU measurements on a 12-kV feeder. https://escholarship.org/uc/item/1qc2b40h Wed, 28 Jun 2017 00:00:00 +0000 Wen, Miles H.F. Arghandeh, Reza von Meier, Alexandra Poolla, Kameshwar Li, Victor O.K. https://escholarship.org/uc/item/1kt5524d This paper describes a research project to develop a network of high-precision phasor measurement units, termed micro-synchrophasors or μPMUs, and explore the applications of μPMU data for electric power distribution systems. https://escholarship.org/uc/item/1kt5524d Wed, 28 Jun 2017 00:00:00 +0000 von Meier, Alexandra Culler, David McEachern, Alex https://escholarship.org/uc/item/17s2s5w7 In this work we address the problem of static state estimation (SE) in distribution grids by leveraging historical meter data (pseudo-measurements) with real-time measurements from synchrophasors (PMU data). We present a Bayesian linear estimator based on a linear approximation of the power flow equations for distribution networks, which is computationally more efficient than standard nonlinear weighted least squares (WLS) estimators. We show via numerical simulations that the proposed strategy performs similarly to the standard WLS estimator on a small distribution network. A key advantage of the proposed approach is that it provides explicit off-line computation of the estimation error confidence intervals, which we use to explore the tradeoffs between number of PMUs, PMU placement and measurement uncertainty. Since the estimation error in distribution systems tends to be dominated by uncertainty in loads and scarcity of instrumented nodes, the linearized method along with the... https://escholarship.org/uc/item/17s2s5w7 Wed, 28 Jun 2017 00:00:00 +0000 Schenato, Luca Arghandeh, Reza Barchi, Grazia Macii, David Von Meier, Alexandra Poolla, Kameshwar https://escholarship.org/uc/item/0dr6p7wc Modern society relies heavily upon complex and widespread electric grids. In recent years, advanced sensors, intelligent automation, communication networks, and information technologies (IT) have been integrated into the electric grid to enhance its performance and efficiency. Integrating these new technologies has resulted in more interconnections and interdependencies between the physical and cyber components of the grid. Natural disasters and man-made perturbations have begun to threaten grid integrity more often. Urban infrastructure networks are highly reliant on the electric grid and consequently, the vulnerability of infrastructure networks to electric grid outages is becoming a major global concern. In order to minimize the economic, social, and political impacts of large-scale power system outages, the grid must be resilient in addition of being robust and reliable. The concept of a power system’s cyber-physical resilience centers around maintaining critical functionality... https://escholarship.org/uc/item/0dr6p7wc Wed, 28 Jun 2017 00:00:00 +0000 Arghandeh, Reza Mili, Lamine Mehrmanesh, Laura von Meier, Alexandra https://escholarship.org/uc/item/66v552xx Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission. ABSTRACT We present XBOS, an eXtensible Building Operating System for integrated management of previously isolated building subsystems. The key contribution of XBOS is the development of the Building Profile, a canonical, executable description of a building and its subsystems that changes with a building and evolves the control processes and applications accordingly. We discuss the design and implementation of XBOS in the context of 6 dimensions of an effective BAS – hardware presentation layer, canonical metadata, control process management, building evolution management, security , scalable... https://escholarship.org/uc/item/66v552xx Mon, 22 May 2017 00:00:00 +0000 Fierro, Gabriel Culler, David E https://escholarship.org/uc/item/5368q9mp There is enormous potential for building-focused applications to improve operation and sustainability, both for classical uses like modeling or fault detection as well as innovative ones like occupant-driven control or grid-aware energy management. We show that a building application stack – that addresses shortcomings of existing antiquated architectures by democratizing sensor data, constructing a framework for reliable and fault-tolerant operation of concurrent applications, and establishing an application programming interface to promote portability throughout the building stock – enables development of advanced applications. We observe the growing importance of applications that integrate sensors and actuators from the building infrastructure with those from “add-on” networks, and show how this design pattern is further empowered by the architecture. To prove the efficacy of the approach, we implement two advanced environmental conditioning applications on a large, commercial... https://escholarship.org/uc/item/5368q9mp Mon, 22 May 2017 00:00:00 +0000 Taneja, Jay Krioukov, Andrew Dawson-Haggerty, Stephen Culler, David https://escholarship.org/uc/item/4nz6g9kg As more and more physical information becomes available, a critical problem is enabling the simple and efficient exchange of this data. We present our design for a simple RESTful web service called the Simple Measuring and Actuation Profile (sMAP) which allows instruments and other producers of physical information to directly publish their data. In our design study, we consider what information should be represented, and how it fits into the RESTful paradigm. To evaluate sMAP, we implement a large number of data sources using this profile, and consider how easy it is to use to build new applications. We also design and evaluate a set of adaptations made at each layer of the protocol stack which allow sMAP to run on constrained devices. https://escholarship.org/uc/item/4nz6g9kg Mon, 22 May 2017 00:00:00 +0000 Dawson-Haggerty, Stephen Jiang, Xiaofan Tolle, Gilman Ortiz, Jorge Culler, David E. https://escholarship.org/uc/item/0h5046n4 We report on an experimental case study of personalized lighting controls built on top of an infrastructure designed to enable rapid development of applications in commercial buildings. Our personalized lighting controls (PLC) use an existing standard commercial building lighting automation system and require no new hardware to deploy. PLC presents occupants with a "shared virtual light switch" accessible online and easily viewable on smart phones by scanning a QR code. It embodies three important design principles: individual empowerment with localized human-centered resolution, token effort for energy consumption and return to a low-power state when inactive. After deploying our lighting controls on two new floors of a large research building on campus, we show a sustainable reduction in lighting energy of 50% to 70% on both floors over 12 weeks, continuing to this day. These savings are found to come from a combination of reducing brightness and keeping lights on less often,... https://escholarship.org/uc/item/0h5046n4 Mon, 22 May 2017 00:00:00 +0000 Krioukov, Andrew Dawson-Haggerty, Stephen Lee, Linda Rehmane, Omar Culler, David https://escholarship.org/uc/item/9vg0316f The increase in high-precision, high-sample-rate telemetry timeseries poses a problem for existing timeseries databases which can neither cope with the throughput demands of these streams nor provide the necessary primitives for effective analysis of them. We present a novel abstraction for telemetry timeseries data and a data structure for providing this abstraction: a timepartitioning version-annotated copy-on-write tree. An implementation in Go is shown to outperform existing solutions, demonstrating a throughput of 53 million inserted values per second and 119 million queried values per second on a four-node cluster. The system achieves a 2.9x compression ratio and satisfies statistical queries spanning a year of data in under 200ms, as demonstrated on a year-long production deployment storing 2.1 trillion data points. The principles and design of this database are generally applicable to a large variety of timeseries types and represent a significant advance in the development... https://escholarship.org/uc/item/9vg0316f Fri, 19 May 2017 00:00:00 +0000 Andersen, Michael P. Culler, David E. https://escholarship.org/uc/item/6ww3s0pq "A Drama in Time"�: How Data and Digital Tools are Transforming Cities and their Communities https://escholarship.org/uc/item/6ww3s0pq Mon, 24 Apr 2017 00:00:00 +0000 Crittenden, Camille https://escholarship.org/uc/item/5t72w1d2 Makers’ Marks: Physical Markup for Designing and Fabricating Functional Objects https://escholarship.org/uc/item/5t72w1d2 Thu, 7 Jul 2016 00:00:00 +0000 Savage, Valkyrie Follmer, Sean Li, Jingyi Hartmann, Bjoern https://escholarship.org/uc/item/7dp1t4p8 IoT &amp; Sustainability: Practice, Policy and Promise https://escholarship.org/uc/item/7dp1t4p8 Wed, 29 Jun 2016 00:00:00 +0000 Nonnecke, Brandie M Bruch, Mia Crittenden, Camille https://escholarship.org/uc/item/61c9d9tz During MOOCs and large on-campus courses with limited face-toface interaction between students and instructors, assessing and improving teaching effectiveness is challenging. In a 2014 study on course-monitoring methods for MOOCs [30], qualitative (textual) input was found to be the most useful. Two challenges in collecting such input for ongoing course evaluation are insuring student confidentiality and developing a platform that incentivizes and manages input from many students. To collect and manage ongoing (“just-in-time”) student feedback while maintaining student confidentiality, we designed the MOOC Collaborative Assessment and Feedback Engine (M-CAFE 1.0). This mobile-friendly platform encourages students to check in weekly to numerically assess their own performance, provide textual ideas about how the course might be improved, and rate ideas suggested by other students. For instructors, M-CAFE 1.0 displays ongoing trends and highlights potentially valuable ideas based... https://escholarship.org/uc/item/61c9d9tz Thu, 5 Nov 2015 00:00:00 +0000 Zhou, Mo Cliff, Alison Krishnan, Sanjay Nonnecke, Brandie Crittenden, Camille Uchino, Kanji Goldberg, Ken https://escholarship.org/uc/item/5z97k3bf The design and assessment of development initiatives is increasingly participatory, where decision makers consider feedback from affected populations. While digital data collection facilitates faster and more reliable analysis, existing data collection tools are not optimized for unstructured qualitative (textual) data and peer-to- peer participant collaboration. In this paper, we propose a system called the Development Collaborative Assessment and Feedback Engine version 1.0 (DevCAFE), a customizable participatory assessment platform that collects and integrates quantitative assessment, qualitative feedback and peer-to-peer collaborative filtering. DevCAFE incorporates a library of statistical analyses for researchers to quickly identify quantitative and qualitative trends while collecting field data. DevCAFE can run on any mobile device with a web-browser and can work with or without Internet connectivity. We present results from two pilot projects: (1) 137 participants evaluating... https://escholarship.org/uc/item/5z97k3bf Thu, 5 Nov 2015 00:00:00 +0000 Nonnecke, Brandie Krishnan, Sanjay Patel, Jay Zhou, Mo Byaruhanga, Laura Masinde, Dorothy Meneses, Maria Elena Martin del Campo, Aejandro Crittenden, Camille Goldberg, Ken https://escholarship.org/uc/item/0bz755bj Online civic engagement platforms accessed via desktops or mobile devices can provide new opportunities for the public to express views and insights, consider the views of others, assist in identifying innovative ideas and new approaches to public policy issues, and directly engage with elected leaders. Existing platforms vary widely in their approaches to: assessment, engagement, ideation, evaluation, and deliberation. We consider three online platforms: the Living Voters Guide, including its earlier iterations Consider.it and Reflect; the Open Town Hall; and the California Report Card. We compare them using the International Association of Public Participation’s “Spectrum of Public Participation” framework. Using a 10-point scale, we evaluate the user interface of each platform in terms of how well it supports the Spectrum’s levels of civic engagement (inform, consult, involve, collaborate, and empower). Results suggest how user interface design affects civic engagement and... https://escholarship.org/uc/item/0bz755bj Thu, 5 Nov 2015 00:00:00 +0000 Nelimarkka, Matti Nonnecke, Brandie Krishnan, Sanjay Aitumurto, Tanja Catterson, Daniel Crittenden, Camille Garland, Chris Gregory, Conrad Huang, Ching-Chang (Allen) Newsom, Gavin Patel, Jay Scott, John Goldberg, Ken https://escholarship.org/uc/item/79j098j8 We describe Lamello, an approach for creating tangible in- put components that recognize user interaction via passive acoustic sensing. Lamello employs comb-like structures with varying-length tines at interaction points (e.g., along slider paths). Moving a component generates tine strikes; a real- time audio processing pipeline analyzes the resultant sounds and emits high-level interaction events. Our main contributions are in the co-design of the tine structures, information encoding schemes, and audio analysis. We demonstrate 3D printed Lamello-powered buttons, sliders, and dials. https://escholarship.org/uc/item/79j098j8 Tue, 18 Aug 2015 00:00:00 +0000 Savage, Valkyrie Head, Andrew Hartmann, Bjoern Goldman, Dan Mysore, Gautham Li, Wilmot https://escholarship.org/uc/item/6fd5v16x <p>We study effects of introducing a real-time chatroom into a massive open online course with several thousand students, supplementing an existing forum. The chatroom was sup- ported by teaching assistants, and generated thousands of lines of discussion by 28% of 681 consenting chat condition participants, mostly on-topic. Despite this, chat activity re- mained low (μ = 8.2 messages per hour) and we could find no significant effect of chat use on objective or subjective de- pendent variables such as grades, retention, forum participa- tion, or students’ sense of community. Further investigation reveals that only 12% of chat participants have substantive interactions, while the remainder are either passive or have trivial interactions that are unlikely to result in learning.</p><p>We also find that pervasive, highly visible chat interfaces are highly effective in encouraging both active and substantive participation in chat. When compared to chat interfaces that are restricted... https://escholarship.org/uc/item/6fd5v16x Tue, 18 Aug 2015 00:00:00 +0000 Coetzee, D Fox, Armando Hearst, Marti Hartmann, Bjoern https://escholarship.org/uc/item/58x364m9 Massive open online courses (MOOCs) rely primarily on discussion forums for interaction among students. We investigate how forum design affects student activity and learning outcomes through a field experiment with 1101 participants on the edX platform. We introduce a reputation system, which gives students points for making useful posts. We show that, as in other settings, use of forums in MOOCs is correlated with better grades and higher retention. Reputation systems additionally produce faster response times and larger numbers of responses per post, as well as differences in how students ask questions. However, reputation systems have no significant impact on grades, retention, or the students' subjective sense of community. This suggests that forums are essential for MOOCs, and reputation systems can improve the forum experience, but other techniques are needed to improve student outcomes and community formation. We also contribute a set of guidelines for running field experiments... https://escholarship.org/uc/item/58x364m9 Tue, 18 Aug 2015 00:00:00 +0000 Coetzee, D Fox, Armando Hearst, Marti Hartmann, Bjoern https://escholarship.org/uc/item/3nh311v9 Expert feedback is valuable but hard to obtain for many de- signers. Online crowds can provide a source of fast and affordable feedback, but workers may lack relevant domain knowledge and experience. Can expert rubrics address this issue and help novices provide expert-level feedback? To evaluate this, we conducted an experiment with a 2x2 facto- rial design. Student designers received feedback on a visual design artifact from both experts and novices, who produced feedback using either an expert rubric or no rubric. We found that rubrics helped novice workers provide feedback that was rated just as valuable as expert feedback. A follow-up analy- sis on writing style showed that student designers found feed- back most helpful when it was emotionally positive and spe- cific, and that providing a rubric increased the occurrence of these characteristics in feedback. The analysis also found that expertise correlated with longer critiques, but not the other fa- vorable characteristics.... https://escholarship.org/uc/item/3nh311v9 Tue, 18 Aug 2015 00:00:00 +0000 Yuan, Alvin Luther, Kurt Krause, Markus Dow, Steven Vennix, Sophie Hartmann, Bjoern https://escholarship.org/uc/item/7ck2f48g Feedback is an important component of the design process, but gaining access to high-quality critique outside a classroom or firm is challenging. We present CrowdCrit, a webbased system that allows designers to receive design critiques from non-expert crowd workers. We evaluated CrowdCrit in three studies focusing on the designer’s experience and bene- fits of the critiques. In the first study, we compared crowd and expert critiques and found evidence that aggregated crowd critique approaches expert critique. In a second study, we found that designers who got crowd feedback perceived that it improved their design process. The third study showed that designers were enthusiastic about crowd critiques and used them to change their designs. We conclude with implications for the design of crowd feedback services. https://escholarship.org/uc/item/7ck2f48g Mon, 17 Aug 2015 00:00:00 +0000 Luther, Kurt Tolentino, Jari-Lee Wu, Wei Pavel, Amy Bailey, Brian Agrawala, Maneesh Hartmann, Bjoern Dow, Steven https://escholarship.org/uc/item/55m5773x Ubiquitous computing devices are often size- and power-constrained, which prevents them from directly connecting to the Internet. An increasingly common pattern is therefore to interpose a smart phone as a network gateway, and to deliver GUIs for such devices. Implementing the pipeline from embedded device through a phone application to the Internet requires a complex and disjoint set of languages and APIs. We present fabryq, a platform that simplifies the prototyping and deployment of such applications. fabryq uses smartphones as bridges that connect devices using the short range wireless technology, Bluetooth Low Energy (BLE), to the Internet. Developers only write code in one language (Javascript) and one location (a server) to communicate with their device. We introduce aprotocol proxy programming model to control remote devices; and a capability-based hardware abstraction approach that supports scaling from a single prototype device to a deployment of multiple devices. To... https://escholarship.org/uc/item/55m5773x Mon, 17 Aug 2015 00:00:00 +0000 McGrath, Will Etemadi, Mozziyar Roy, Shuvo Hartmann, Bjoern https://escholarship.org/uc/item/54v8900k Searching for scenes in movies is a time-consuming but cru- cial task for film studies scholars, film professionals, and new media artists. In pilot interviews we have found that such users search for a wide variety of clips—e.g., actions, props, dialogue phrases, character performances, locations— and they return to particular scenes they have seen in the past. Today, these users find relevant clips by watching the entire movie, scrubbing the video timeline, or navigating via DVD chapter menus. Increasingly, users can also index films through transcripts—however, dialogue often lacks vi- sual context, character names, and high level event descrip- tions. We introduce SceneSkim, a tool for searching and browsing movies using synchronized captions, scripts and plot summaries. Our interface integrates information from such sources to allow expressive search at several levels of granularity: Captions provide access to accurate dialogue, scripts describe shot-by-shot actions and settings,... https://escholarship.org/uc/item/54v8900k Mon, 17 Aug 2015 00:00:00 +0000 Pavel, Amy Goldman, Dan Hartmann, Bjoern Agrawala, Maneesh https://escholarship.org/uc/item/3x2192w9 This research investigates how to introduce synchronous interactive peer learning into an online setting appropriate both for crowdworkers (learning new tasks) and students in massive online courses (learning course material). We present an interaction framework in which groups of learners are formed on demand and then proceed through a sequence of activities that include synchronous group discussion about learner-generated responses. Via controlled experiments with crowdworkers, we show that discussing challenging problems leads to better outcomes than working individually, and incentivizing people to help one another yields still better results. We then show that providing amini-lesson in which workers consider the principles underlying the tested concept and justify their answers leads to further improvements. Combining the mini-lesson with the discussion of the multiple-choice question leads to significant improvements on that question. We also find positive subjective responses... https://escholarship.org/uc/item/3x2192w9 Mon, 17 Aug 2015 00:00:00 +0000 Coetzee, D Lim, Seongtaek Fox, Armando Hartmann, Bjoern Hearst, Marti