VictorJuiz/thesis huggingface dataset:
The Impact of Adverse Weather on Freeway Bottleneck Performance

Congestion on freeways occurs when demand exceeds the available capacity. Common causes of recurring congestion, also known as freeway bottlenecks, include lane drops, on-ramp merges, and weaving sections. Adverse weather reduces traffic speeds and the maximum queue discharge flow at freeway bottlenecks. However, the impact of weather characteristics on bottleneck discharge flows has not been systematically investigated. This research investigated the relationship between bottleneck queue discharge flow and weather characteristics including rainfall intensity, wind speed, and visibility./nQueue discharge rates at four isolated merge bottlenecks within Orange County, California were measured utilizing an established methodology of cumulative count and occupancy curves. An analysis of how queue discharge varied by rainfall intensity revealed reduced discharge ranging from 5% in drizzle (rainfall <0.02 inches/hour) up to 27% in heavy rainfall (rainfall >0.1 inches/hour). However, variation in this single weather characteristic only accounted for a small percentage of the variability in discharge flow, particularly in light rain. Several hypotheses were proposed and tested utilizing the two additional variables of wind speed and visibility and dividing the periods of discharge flow into three groupings. Analyses based on these hypotheses better described the variation in queue discharge flow than the analysis with rainfall intensity alone. A model was developed to predict bottleneck discharge flow by combining data points from all sites. This model predicted that an increase in rainfall intensity of 0.1 inches per hour reduced queue discharge by approximately 1.8% at all sites after the onset of congestion./nThis research shows that weather characteristics are an important predictor of bottleneck queue discharge rates. Forecasted weather patterns could be used to predict reductions in bottleneck capacity. Complementary research building on this work by examining changes in trip start time during adverse weather would allow an improved prediction of vehicle delay and travel time reliability. This information would allow traveler information services to incorporate weather characteristics in order to provide more accurate predicted route times for commuters.

Advisor: Skabardonis, Alexander
Measurement of the top quark pair differential cross-section at high top quark transverse momentum in 8 TeV proton-proton collision data collected with the ATLAS detector at the LHC

This dissertation presents the first measurement of the top quark pair differential cross-section as a function of the hadronic top candidate transverse momentum that uses boosted top quark identification techniques. This allows to extend the measurement into the TeV range, with the cross-section reported for top candidate transverse momentum between 300 GeV and 1.2 TeV. The measurement is performed using events reconstructed in the lepton+jets channel in 20.3 fb$^{-1}$ of $\sqrt{s}$ = 8 TeV proton-proton collision data collected by the ATLAS experiment. Previous measurements have reported the cross-section as a function of the top quark kinematics. To allow for a robust top candidate definition, independent of assumptions required to isolate the kinematics of individual partons, the cross-section presented here is reported at the stable particle level. The cross-section is reported within a fiducial region closely following the detector-level event selection to minimize uncertainties associated with extrapolations beyond the detector acceptance. To illustrate the evolution of the uncertainties associated with extrapolating the particle level results to the usual top parton definition, the results are also presented within the full phase-space at the parton level.

Advisor: Shapiro, Marjorie
Driving Freedom, Navigating Neoliberalism: San Francisco Taxi Workers, Juridical Precarity, and the Politics of Work Law

Labor conditions and real wages in the United States have atrophied over the past thirty years, weakened by neoliberal governance, shifting business models, and the decline of private-sector unions. This dissertation examines the San Francisco taxi industry as a site of these changes, and uses archival research and ethnography to understand the emerging intersection of structural changes, political and legal activism, and worker identities. I argue that free market practices and new regimes of work have transformed not only the nature of work, but also the subjectivities of U.S. workers and the dynamics of collective worker politics./nThrough a legal and historical analysis of how employment identities and work are constructed under U.S. law, my dissertation traces the bifurcation of worker classification into employees and independent contractors from the New Deal to the present. I show how the erratic legal analysis of who constitutes a state-protected employee has its origins not in an objective reality about the changing nature of work itself, but rather in shifting cultural meanings about the individual in relation to phases of capitalism. Drawing on court decisions and the political and legal history of San Francisco taxi drivers, my research situates the production of juridical precarity alongside the sociolegal construction of taxi drivers as working-class entrepreneurs./nComplementing this historical analysis, my ethnographic research examines the contemporary politics of work and work law amongst cab drivers and those who advocate on their behalf. I argue, contrary to existing labor law scholarship, that post-classification legal challenges to the independent contractor identity are ineffective; they reify the inequalities between "master" and "servant" by ignoring the subjectivities and desires of workers. My interviews reveal that for San Francisco taxi workers, legal work categories have become embodied cultural and political identities. Many immigrant taxi workers, for example, embrace their independent contractor status because it provides legal validation for their identities as aspiring entrepreneurs, propelling them closer to the possibility of upward social mobility. For my interlocutors, working-class entrepreneurship, even alongside material deprivation and poor working conditions, enables an affective freedom and re- affirms a working-class masculinity, lost amidst shifts in modes of capitalist production./nBuilding on these historical and ethnographic findings, my dissertation considers new possibilities of worker collectivities and a new politics of work law. I consider "worker centers" as sites for potentially radical work politics. Precisely because they function outside the context of existing and outmoded forms of labor law, worker centers, I argue, respond to the subjectivities and intersectional identities of contemporary immigrant workers and have powerful potential to compel a new politics of work and work law attentive to ever-shifting forms of labor.

Advisor: Albiston, Catherine
Following Politics: Russian Youth Activism in Post-Socialist Latvia

My dissertation is based on fieldwork conducted in Latvia. Latvia is frequently introduced with a demographic statistic which characterizes 60% of its population as Latvian and 40% as Russian. The ensuing discussion focuses on nationalism and ethnic tensions--terms central to scholarship on Eastern Europe. Below, I problematize the ubiquity of these terms in accounts of post-socialist politics. Drawing on ethnographic research with Latvia's Russian youth organizations, I argue that these terms obscure a phenomenon that has an important empirical bearing: the fact that actors, who are by no means marginal in electoral politics, have a stake in remaining legible within a sphere of action characterized by ethnic division; and, at the same time, challenge forms of action based on ethnic solidarity./nRecent events in Ukraine have once again brought to the fore the problematic role of ethnic Russians in post-Soviet republics. In much of political commentary Russians living outside of the Russian Federation appear as pawns of Kremlin's attempt to regain its dominance over the post-soviet world; as subjects injured by nationalizing elites' attempt to undo effects of Soviet Russification; and, fundamentally, as reactionary supporters of a (pro-) Russian autocracy. In fact, over the last decade policy makers from the European Union have spent a great deal of effort working with Russian activists in Eastern Europe in a hope to shift their political allegiances; to teach them the value of national sovereignty; and, fundamentally, to get them to differentiate between democratic freedoms (inherent in European institutions) and selective privileges (held over from the Soviet period)./nIn my dissertation, I challenge the assumption that Russians living outside the Russian Federation are pawns of Muscovite expansion, and, in the same vein, critique the hope that they make become agents of European democratization. Analyzing Latvia's Russian youth activists' ambitious for meaningful elected office, I argue that despite having different geopolitical and ideological orientations, EU- and RF-programs are equally likely to perpetuate parliamentary gridlock, voter apathy, and anti-political sentiment. In a related vein, I explore how youth activists turn to late-socialist practices in an attempt to create viable alternatives to both "pro-Russian" and "pro-European" positions; and how these alternatives have immense potential to draw together young people of different ideological persuasions, ethnic identities and life styles.

Advisor: Cohen, Lawrence
Ultra‐low Power Wake‐up Radio for Low Activity Wireless System

Recent advances in low power radio design have enabled a broad range of low activity applications such as smart utilities, health monitoring, building and industry automation, automotive control and monitoring, wireless control and etc. The key challenge to implement these applications is to reduce the average power consumption spent on wireless communications. A traditional way to solve this is to implement protocol based duty cycling which leads to a tradeoff between reduced average power consumption and increased system latency. A smarter solution is to use a dedicated wake-up receiver continuously monitoring the channel and activating the main receiver upon detection of a wake-up signal. The use of a wake-up receiver helps to improve the overall power performance while keeping the system latency bounded./nThis dissertation addresses challenges and concerns of designing an ultra-low power high performance wake-up radio. It proposes a two-step wake-up architecture including energy detection mode and address detection mode to reduce the active power dissipation meanwhile improving the robustness and reliability of the system. Design metrics has been provided to serve as a guideline for detailed circuit implementations. Based on that, a wake-up radio prototype has been built in TSMC 65nm standard CMOS targeting 915MHz band for IEEE 802.15.4g. This prototype focuses on improving the sensitivity performance at an ultra-low power level. It consumes only 45ÂµW in energy detection mode. With 20Âµs detection time, it is able to achieve a sensitivity of -90dBm at 10-2 error rates. In address detection mode, it consumes 300 ÂµW and is able to achieve a sensitivity of -74.5dBm at 10-3 BER.

Advisor: Rabaey, Jan M
Wireless Neural Interface Design

Neural interfaces promise to radically change medicine. Currently, amputees and persons suffering from debilitating brain disorders lack a way to regain mobility and freedom. By recording and interpreting signals from the motor control regions of the brain, researchers have already demonstrated rudimentary control of robotic prosthetic arms in primate and human trials. Now, the next generation of neural interface electronics must provide the required advances in size and power consumption to enable long-term viability of complex, high degree-of-freedom prosthetic devices./nThis dissertation presents two complete neural interface systems to address two key challenges: evading the brain's foreign body response to achieve long probe longevity, and scaling wireless, implantable systems to high channel counts. The first, a self-contained, 0.125 mm2, 4-channel wireless recording system, achieves an unprecedented level of miniaturization. This opens the possibility of free-floating neural nodes in the brain tissue, which eliminates strain caused by transcranial wires. Ultimately, this may lead to probes that out- smart the brain's biological response, and provide stable, long-term recordings for chronic brain-machine interfaces. The second system achieves an unprecedented level of integration, combining 64 recording channels, 16 stimulation channels, and neural data compression onto a single 4.78 mm2 IC. Furthermore, the IC achieves substantial improvements in power and area versus state-of-the-art. These improvements in performance and functionality enable neural recording systems that scale up to thousands of channels, or scale down to extremely compact, low weight, low area, wireless interfaces.

Advisor: Rabaey, Jan
Alon, Elad
A Hybrid Dynamical Systems Theory for Legged Locomotion

Legged locomotion arises from intermittent contact between limbs and terrain. Since it emerges from a closed-loop interaction, reductionist study of body mechanics and terrestrial dynamics in isolation have failed to yield comprehensive strategies for forward- or reverse-engineering locomotion. Progress in locomotion science stands to benefit a diverse array of engineers, scientists, and clinicians working in robotics, neuromechanics, and rehabilitation. Eschewing reductionism in favor of a holistic study, we seek a systems-level theory tailored to the dynamics of legged locomotion./nParsimonious mathematical models for legged locomotion are hybrid, as the system state undergoes continuous flow through limb stance and swing phases punctuated by instantaneous reset at discrete touchdown and liftoff events. In their full generality, hybrid systems can exhibit properties such as nondeterminism and orbital instability that are inconsistent with observations of organismal biomechanics. By specializing to a class of intrinsically self-consistent dynamical models, we exclude such pathologies while retaining emergent phenomena that arise in closed-loop studies of locomotion./nBeginning with a general class of hybrid control systems, we construct an intrinsic state-space metric and derive a provably-convergent numerical simulation algorithm. This resolves two longstanding problems in hybrid systems theory: non-trivial comparison of states from distinct discrete modes, and accurate simulation up to and including Zeno events. Focusing on models for periodic gaits, we prove that isolated discrete transitions generically lead the hybrid dynamical system to reduce to an equivalent classical (smooth) dynamical system. This novel route to reduction in models of rhythmic phenomena demonstrates that the closed-loop interaction between limbs and terrain is generally simpler than either taken in isolation. Finally, we show that the non-smooth flow resulting from arbitrary footfall timing possesses a non-classical (Bouligand) derivative. This provides a foundation for design and control of multi-legged maneuvers. Taken together, these contributions yield a unified analytical and computational framework -- a hybrid dynamical systems theory -- applicable to legged locomotion.

Advisor: Sastry, S. Shankar
Improving Energy Efficiency in CNC Machining

We present our work on analyzing and improving the energy efficiency of multi-axis CNC milling process./nDue to the differences in energy consumption behavior, we treat 3- and 5-axis CNC machines separately in our work. For 3-axis CNC machines, we first propose an energy model that estimates the energy requirement for machining a component on a specified 3-axis CNC milling machine. Our model makes machine-specific predictions of energy requirements while also considering the geometric aspects of the machining toolpath. Our model - and the associated software tool - facilitate direct comparison of various alternative toolpath strategies based on their energy-consumption performance./nFurther, we identify key factors in toolpath planning that affect energy consumption in CNC machining. We then use this knowledge to propose and demonstrate a novel toolpath planning strategy that may be used to generate new toolpaths that are inherently energy-efficient, inspired by research on digital micrography -a form of computational art./nFor 5-axis CNC machines, the process planning problem consists of several sub-problems that researchers have traditionally solved separately to obtain an approximate solution. After illustrating the need to solve all sub-problems simultaneously for a truly optimal solution, we propose a unified formulation based on configuration space theory. We apply our formulation to solve a problem variant that retains key characteristics of the full problem but has lower dimensionality, allowing visualization in 2D. Given the complexity of the full 5-axis toolpath planning problem, our unified formulation represents an important step towards obtaining a truly optimal solution./nWith this work on the two types of CNC machines, we demonstrate that without changing the current infrastructure or business practices, machine-specific, geometry-based, customized toolpath planning can save energy in CNC machining.

Advisor: McMains, Sara
Low Noise, Low Power Cavity Optomechanical Oscillators

Cavity Optomechanical oscillators (OMOs) rely upon photon radiation pressure to induce harmonic mechanical motion of a micron-scale light resonator. Unlike most oscillators, optomechanical oscillators require only CW input light without the need for electronic feedback and so hold promise for their novelty. In an optical cavity of sufficient quality factor, the transduction from photons to phonons can be quite efficient as we characterized optomechanical cavities which only required 17 microwatt input optical power to induce mechanical oscillation. The question then remains whether OMOs can be made low noise and of course better yet, low noise and low power./nBy characterizing various materials and designs, it is shown that indeed OMOs may be made low noise and low power through maximization of the mechanical quality factor - a common quest for MEMs designers. With an emphasis on wafer-scale processes on silicon substrates, OMOs constructed from reflowed phosphosilicate glass, silicon nitride, and silicon were characterized and modeled. Due to non-linear light-matter interactions, OMOs are also known to produce RF frequency combs with an optical carrier. These combs were investigated and a method to produce a frequency comb spanning more than 6GHz from a 52MHz carrier was found. As a demonstration for how an OMO may be utilized in a chip-scale atomic clock, the 9th harmonic of a voltage-tunable device was phase-locked to a low noise microwave reference resulting in an 85dB reduction in phase noise at 1Hz offset from the carrier.

Advisor: Wu, Ming C
Science, Technology, and Know-How: Exploitation of German Science and the Challenges of Technology Transfer in the Postwar World

This dissertation is a comparative study of the American, British, and French efforts to exploit German science and technology following the Second World War, and through this, a transnational history of technology transfer, diplomacy, and science-state interaction in the postwar world. In the wake of the importance of science-based technologies in the Second World War, science became closely linked with diplomacy, scientific expertise took on new meanings and importance in government in each of these three nations, and the occupation of Germany created a perceived opportunity to simultaneously shape Germany's future and boost domestic industrial technology. Across the world, the relationships between science and the state changed rapidly in the postwar years, though with important national differences shaped by institutions and values./nThe central argument of the dissertation is that different assumptions and beliefs about technology transfer, and in particular conceptions of the importance of 'know-how' or tacit knowledge, fundamentally shaped on-the-ground policy decisions in different ways in each of these nations; and that these decisions, in turn, had important consequences for international diplomacy and domestic science and industrial policy in each of these nations. This dissertation examines the ways in which science and technology fundamentally reshaped, and were fundamentally reshaped by, larger forces and trends in twentieth century history. More specifically, these attempts at scientific intelligence gathering on an unprecedented scale drew upon and shaped the national and international structures for communicating science; they tied together science, technology, and intelligence communities in new ways; and they brought the difficulties of technology transfer to the attention of business and legal communities at a crucial time in the development of multinational corporations and internationalization of business.

Advisor: Carson, Cathryn
Warai: Laughter, Comedy and the Television Cultures of 1970s, 80s and 90s Japan

An examination of Japanese television comedy from the 1970s, 80s and early 90s, the dissertation traces changes in laughter's imagined social role, as well as its use within the television medium. Narratives of the era frequently depict the period as one characterized by a turn towards consumerism and political apathy, and single out television's role in this shift. I employ television comedy as a lens through which to re-examine these shifts. My analysis focuses on the genre's laughter as discursive object, and reveals the emergence within Japanese television of an ambivalent form of laughter, which functioned within the medium to both order and disrupt. While television laughter worked to coordinate the affective rhythms of viewers, that same laughter hid beneath its seemingly cheery surface discordant notes and jarring beats. Against this backdrop, I consider both the mechanisms that maintain media culture in Japan, as well as the possibilities for eruption that still lie below its surface./nComprised of four chapters, the dissertation divides the years covered into roughly two, overlapping phases. The first two chapters cover a period from the early 1970s to the mid-80s, and explore the rise on Japanese television of communally binding forms of laughter. The first chapter considers how producers of the popular comedy show Hachi ji da yo! Zen'in shugo (It's 8 O'clock! Everyone Gather `Round, 1969-1985) contrived to produce on the show a rhythmic and socially unifying form of comedy. The second chapter focuses on the show Kinchan no doko made yaru no! (How Far Will Kinchan Go! 1976-1986), and examines how its producers mobilized the show's putatively "warm" tone of laughter in constructing the show's affective pull on its viewers./nThe final two chapters cover a period form the early 1980s to the mid-90s, and explore the eruption within Japanese television of more explosive and disruptive forms of laughter. The third chapter turns to the 1980-81 manzai (duo standup comedy) revival, and examines how boom-era shows co-opted the voice of youth laughter as a signifier of authenticity within the broadcast. The final chapter examines the evolution of the Japanese reality-style "documentary variety" genre, and considers how the genre employed its "documents of laughter" to transform sites of political and social contestation into spaces of laughter and mischief, and thus divorce them of their historical context.

Advisor: O'Neill, Daniel