Two-dimensional (2D) nanomaterials have significantly advanced biosensor technology. Their unique properties enable highly sensitive and specific biomolecule detection, streamlining diagnostics and environmental monitoring with their rapid and efficient capabilities. In this research, we conducted a comprehensive investigation into the development and optimization of flexible optoelectronic biosensors using 2D molybdenum disulfide (MoS2) for the rapid selective detection of biomolecules. Through a series of experimental studies, we explored innovative strategies that leverage the unique photoresponse characteristics of MoS2 and the electrical conductivity of graphene to enhance biosensor performance. In the first part of our study, we introduced a MoS2-based optoelectronic biosensor that demonstrates significantly improved sensitivity and selectivity under photonic excitation. Following this, we extend this approach by integrating MoS2 with graphene electrodes to address conductivity limitations, resulting in a hybrid optoelectronic biosensor with superior sensitivity. Our research further advanced by examining vertical heterostructures of MoS2 and graphene, presenting two configurations that optimize biomolecule sensing capabilities. Our findings reveal that biofunctionalized MoS2 platforms and MoS2 and graphene heterostructures Field-Effect Transistors (FETs) achieve high sensitivity and specificity, significantly advancing biosensor technology. These innovations offer fresh perspectives and methods to boost biosensor performance, paving the way for health and environmental breakthroughs.

Understanding the rainfall-runoff patterns has been a central focus in watershed hydrology. This dissertation investigates the effects of climate variability, wildfire, and subsurface storage on rainfall-runoff responses of small watersheds in coastal California under a Mediterranean climate. I examine orographic rainfall distributions calculated with multiple spatial interpolation methods, which rely on topographic information, and assess the performance and bias of these methods. I present evidence that geographic weighted regression (GWR) performs well in generating spatial distributions of event-based rainfall.I use time series analysis to examine event-based rainfall and runoff data under the impacts of synoptic climate variability (atmospheric rivers; AR, Madden Julian Oscillation; MJO, El Niño- Southern Oscillation; ENSO). The inter-relationships of synoptic climate variability indicate that ENSO phases are the dominant factor in altering AR-associated large-rainfall events in the wet seasons (Nov.-Apr.), especially in wet years. Wavelet power spectra in the runoff data indicate that large floods, generated under the AR events and MJO phases, coincide in time with strong El Niño events.I assess post-fire hydrologic responses using two metrics, differences in event-based storm runoff and flow duration curves (FDC) and event-based rainfall-runoff regression models. I present several findings during post-fire periods: large inter-storm and inter-annual variability of rainfall and runoff, declining differences in event-based runoff, and a downward shift of annual FDCs. These observations can be attributed to precipitation variability, and large coverage of bedrock within the burned areas. Large variation in high flows and similar values of low flows evident in annual post-fire FDCs reflect the runoff response to fire is smaller than the effects of inter-annual variation in rainfall during the post-fire period. I identify water storage dynamics in soil and fractured bedrock using simple water balance models. Recession constants generated from the linear reservoir model indicate that water released from soils and bedrock behaves similarly in four selected watersheds. Water stored in fractured bedrock zones remains slightly changed in the dry seasons. However, during the progression of wet seasons, it may react quickly to rain storms, and lead to large changes to groundwater storage.

After World War II, Chinese films shot in Taiwan and Hong Kong began to play a significant role constructing and disseminating images of Chinese culture and its urban environments to pan-Chinese regions of the world and beyond. To comprehend the relationship between those Chinese films and their urban settings, particularly in Taipei and Hong Kong, numerous scholars in the field of Chinese cinematic urbanism engaged in analyses of the highly aestheticized spatial representations in the films, as well as on the cultural negotiation of Chineseness within a context of political tension, and the issues arising from the rapid capitalization of Chinese cities. However, from the 1990s, the global popularity of Hollywood movies threatened the film industry both in Taiwan and Hong Kong. Concurrently, Mainland China rose in stature to supplant Taiwan and Hong Kong as the seat of political, economic, and cultural “Chineseness”. To respond to these changes, film industry executives in Taiwan and Hong Kong began to seek new ways to survive, sparking a process in which the relationship between cities and the film industries grew more complex. Numerous cinematic ventures were created to intentionally address considerations of film tourism, urban marketing, intervention in the urban process, and the formation of localism.

In 2008, for example, a popular Taiwanese movie Cape No. 7 induced a fever of domestic tourism, drawing numerous visitors to its shooting locales. As a result of this phenomenon, local governments, in particular those of two major cities, Taipei and Kaohsiung, recognized the potential for a new type of relationship between the film industry, cities’ imaginaries, and the promotion of cities as tourist destinations. They began to sponsor films that highlighted the appeal of special urban attractions in their cities—films intended to foster tourist activity and advertise a specially crafted urban imaginary. Meanwhile, film executives and the government in Hong Kong collaborated to produce a novel nostalgic film genre intended to foster the formation of localism toward Hong Kong. In these films, a specific historical architecture or neighborhood was chosen as the setting for films that evoked the Hong Kong spirit and collective memories of Hong Kong people, distinguishing this city’s imaginary from the otherwise dominant image of Mainland Chinese cities. The films then attracted local audiences to visit the filmic locales, an experience which further developed the domestic audiences’ local identity. In all of these cases, the distinctive imaginary of each city was developed and distributed, and a new relationship between cities and cinema emerged, one with a powerful influence on the film industries, the development of physical urban environments, and the negotiations between Chineseness and local identities in Taiwan and Hong Kong.

This dissertation research offers an in-depth examination of this historical movement from the late 2000s to the present, though archival research, film analysis, and participatory observation, exploring the ways in which linchpin cities in Taiwan and Hong Kong, through cinematic production and representation, induced tourism and pursued alternative models for pan-Chinese urban development, in the process further constructing their local identities. Particularly, three cities—Kaohsiung, Taipei, and Hong Kong—and several specific movies that have had crucial effects on each city’s urban imaginary and physical environment will be addressed. In the case of Kaohsiung, I examine the municipal government’s initiation of the policy of film sponsorship through assisting a TV series, Black & White, and its sequel films. Black and White was used to publicize the municipal government’s political achievements and transform Kaohsiung’s urban imaginary from a postindustrial port city to a global harbor city with Taiwanese cultural distinctions, which further established Kaohsiung as a potential locus for the film industry. Following the achievement of Kaohsiung, the Taipei municipal government first established a similar policy of film sponsorship and later became the most important supporter for the present redevelopment of the Taiwanese film industry through quickly adjusting its film policies to suit the filmmakers’ demands.

Furthermore, in Dadaocheng, a specific district of Taipei, these circumstances led to the transformation of a preserved historical district with a long and diverse political and cultural legacy into a popular tourist attraction as well as a popular filming location, as cinematic representations of Dadaocheng resulted in interventions in its spatial preservation and economic redevelopment process. Tracing both the failures and successes of cinematic interventions in Dadaocheng, this research attempts to capture the complicated dynamics among different agents—government bureaucrats, city planners, filmmakers, and existing urban communities—whose negotiations have had a vital impact in shaping contemporary cinematic urbanism and localism in Taiwan. In the meantime, as Taiwan’s political, economic, and cultural counterpart, Hong Kong offers the comparison case that completes the discourse. The research of cinematic intervention in Hong Kong examines the effects of a government-sponsored nostalgic film, Echoes of the Rainbow, recalling the collective memory of developing Hong Kong in the 1970s. This movie was successfully deployed to halt an urban renewal project and persuade the government to preserve and renovate its main shooting location, a historical neighborhood in Central Hong Kong.

Building upon previous studies that provided the theoretical foundation for cinematic urbanism studies, this dissertation examines the novel phenomenon of contemporary pan-Chinese cinematic urbanism in Taiwan and Hong Kong to illustrate its agency in urban processes.

Energy demand increases rapidly with industrial and economic development. Fossil fuels, oil, coal, and gas as conventional energy sources are non-renewable and will run out eventually. Their excessive consumption produces a large amount of CO2 which directly leads to the greenhouse effect and climate change. Low-carbon renewable technologies need to be found to solve the global energy crisis. Fusion energy stands out among several alternative energy approaches such as wind, solar, biomass, and conventional nuclear fission, with the advantage of being safe, clean, and virtually inexhaustible. It is difficult to study the fusion energy in the plasma state with the problem of instability under extremely high temperatures caused by the reaction between particles. The magnetic field confinement which usually is a Tokamak device is devised for the burning plasma to keep the particles effectively within its center. To understand and improve the confinement and stability, millimeter-wave and microwave diagnostics are required to monitor the inside status of the burning plasma of its turbulent structures and fluctuations.Two commonly used approaches to microwave diagnostics are microwave imaging reflectometer (MIR) which is an active radar-like system comprised of both transmitter and receiver to analyze the electron density properties and electron cyclotron emission imaging (ECEI) which directly receives the emission signals from the plasma and provides 2-D measurement on electron temperature and its fluctuations. Microwave and millimeter-wave wideband receivers play an important role in MIR and ECEI plasma diagnostics. Previously, V-band (55-75 GHz) and W-band (75-110 GHz) receivers in 90 nm-CMOS and 100 nm-GaAs technologies have been successfully designed, and the W-band one has been deployed for ECEI equipment on DIII-D. This dissertation describes the latest progress in receiver development including the F-band (110~140 GHz) receiver chip development using TSMC 65-nm CMOS technology, W-band (75-110 GHz) receiver chip design using HRL T3 40-nm GaN technology, G-band (130~185 GHz) LNA design using Global Foundries 45-nm RFSOI technology, and the V-band (55~75 GHz) MIR receiver array integration. The F-band receiver chip includes an RF-LNA, actively biased broadband mixer, 2~18 GHz IF-Amp, 36~47 GHz tripler, and a 110~140 GHz driver amplifier. The chip size is 1250 × 1150 μm2 and its total power consumption is 250 mW at 1.8 V bias or 400 mW at 2.5 V. The on-wafer measured conversion gain is 7 dB, NF is 14 dB at 110 GHz, and the RF-IP1dB is -21 dBm. In addition to fusion plasma diagnostics, this 65-nm CMOS receiver is applicable for use in applications such as high-speed local networking around the 118 GHz oxygen absorption line and millimeter-wave test instruments in the post-5G era. The W-band receiver chip has the same circuit blocks as the F-band one, but a larger size of 3 × 5 mm2 and better performance of a higher gain and lower noise figure. Its simulated conversion gain is larger than 25 dB, double sideband noise figure is around 5 dB. The RF-IP1dB is -27 dBm. The G-band LNA as the preliminary attempt for the G-band receiver has a simulated small signal gain of 18 dB and a noise figure of 7 dB. The RF IP1dB is -16 ~ -19 dBm. The V-band receiver chip designed by the former student Jo-Han Yu has been integrated into the receiver module with a feed horn, waveguide-to-CPWG transition, LO multiplier chain, IF amplifier chain, and DC power supplies. The measured conversion gain is larger than 30 dB, and the typical single-sideband noise figure is 16 dB. The receiver modules have been assembled into a receiving array in the enclosure which will be installed on DIII-D with the V-band transmitter to serve as the new generation MIR system for plasma diagnostics.

In this dissertation, we consider a three-layer supply chain with a manufacturer, a reseller, and a salesperson. In the manufacturer's target market, the sales outcome is jointly determined by the market condition and the salesperson's sales effort. While the salesperson can privately observe both, the manufacturer observes none. If the manufacturer contracts with the salesperson directly, it faces a mixture of the adverse selection and moral hazard problems. Because the reseller has a closer contact to the market and the salesperson, she can better monitor the two pieces of private information. Therefore, the manufacturer may delegate the sales responsibility to the reseller to indirectly mitigate the inefficiency caused by information asymmetry. As different resellers have different monitoring expertise, the manufacturer faces a supply chain construction problem by deciding which reseller to delegate to. Unlike traditional two-layer principal-agent problems in which the principal searches for the optimal direct monitoring functions, this dissertation studies the optimal strategy of indirect monitoring.

Using the mechanism design approach and extending the traditional principal-agent model, we discuss the manufacturer's reseller selection strategy and the embedded salesforce compensation problem faced by the reseller. When the reseller can either observe the market condition or the sales effort, we show that the manufacturer should delegate to the latter one. We then study the reseller's resource allocation problem when the reseller can estimate the two aspects, both imperfectly, subject to a fixed budge constraint. When the reseller can only estimate the market condition, we show that the manufacturer's expected profit is convex on the reseller's accuracy. Collectively, our results deliver insights to manufacturers in selecting their reselling partners with various monitoring abilities and answers how the reseller's monitoring functions affect the supply chain performance.

Pre-2018 CSE ID: CS2001-0680

There are typically multiple equilibrium outcomes in the Crawford-Sobel (CS) model of strategic information transmission. This paper identifies a simple condition on equilibrium payoffs, called NITS (no incentive to separate), that selects among CS equilibria. Under a commonly used regularity condition, only the equilibrium with the maximal number of induced actions satisfies NITS. We discuss various justifications for NITS, including perturbed cheap-talk games with nonstrategic players or costly lying. We also apply NITS to other models of cheap talk, illustrating its potential beyond the CS framework.