VictorJuiz/thesis huggingface dataset:
Public health response systems in action: Retrospective analyses of acute and emergency incidents to inform future preparedness

While public health threats have always existed, federal investment in preparedness has surged in the past decade. Interested in evaluating return on their investments in public health preparedness, congressional and public stakeholders have pushed for the development of assessment, accountability, and improvement measures. However, the evidence base to support this priority has lagged behind. There is still little agreement on how to measure, let alone improve, public health response performance. A number of challenges have been cited as barriers to research advancements in this field, including the infrequent nature of large-scale public health emergencies, heterogeneity of emergency events and of public health delivery structures, and difficulties gaining access to incident leadership during real-world emergencies. Limitations in our knowledge pose significant barriers to public heath authorities who seek to evaluate their own response capacity and direct resources towards evidence-based improvements. They also hinder stakeholders' ability to develop valid, reliable, and realistic measures to evaluate how well health public health systems are performing. In the case of acute events, the quality of public health performance can make a difference in the number of lives saved, illnesses or injuries averted, and the economic and social costs to a community. Consequently, it is of utmost importance to ensure that the evidence base used to guide the development of standards and measures is the best possible./nThis dissertation includes examples of three research initiatives that seek to: (1) improve the public health emergency response evidence base by characterizing key structural and functional dimensions of the response systems during real-world urgent and emergency events, (2) identify factors which influence variation in this system, and (3) demonstrate that advancements in conceptual models of public health response operations are both possible and relevant.

Advisor: Aragon, Tomas J
Reingold, Arthur
Ultrasonic 3D Rangefinder on a Chip

Optical 3D imagers for gesture recognition, such as Microsoft Kinect, suffer from large size and high power consumption. Their performance depends on ambient illumination and they generally cannot operate in sunlight. These factors have prevented widespread adoption of gesture interfaces in energy- and volume-limited environments such as tablets and smartphones. Gesture recognition using sound is an attractive candidate to overcome these difficulties because of the potential for chip-scale solution size, low power consumption, and ambient light insensitivity./nOur research focuses on building a 3D ultrasonic rangefinder system using batch-fabricated micromachined aluminum nitride (AlN) ultrasonic transducer arrays and custom CMOS electronics. The system uses pulse-echo time-of-flight to localize targets from their echoes. We use millimeter--wave ultrasound, which enables compact ultrasonic arrays which can measure range and direction to a target. The relatively slow speed of sound allows the use of low--speed, low-power readout electronics./nIn this dissertation, we will present the design methodology for a prototype ultrasonic rangefinder system. We will show how the choice of basic system specifications affects the mechanical transducer design and the interface circuit design. We will present a physics-based model of an ultrasound transducer which accurately predicts device operation. We will present measured results from an ultrasonic 3D gesture recognition system which uses an array of AlN MEMS transducers and custom readout electronics to localize targets over a ±45° field of view up to 1m away. The 0.18μm CMOS readout ASIC comprises 10 independent channels with separate high voltage transmitters, readout amplifiers, and ADCs. Power dissipation is 400μW at 30fps, and scales to 5μW/ch at 10fps.

Advisor: Boser, Bernhard E
The representation theory of the exceptional Lie superalgebras F(4) and G(3)

This thesis is a resolution of three related problems proposed by Yu. I. Manin and V. Kac for the so-called exceptional Lie superalgebras F(4) and G(3). The first problem posed by Kac (1978) is the problem of finding character and superdimension formulae for the simple modules. The second problem posed by Kac (1978) is the problem of classifying all indecomposable representations. The third problem posed by Manin (1981) is the problem of constructing the superanalogue of Borel-Weil-Bott theorem.

Advisor: Serganova, Vera
Wolf, Joseph A
Validating Causal Estimates in Experimental and Observational Designs

Social scientists and policy makers continue to put increased emphasis on identifying causal effects in their research, employing the myriad of novel approaches that have been developed in recent years. With this rise in the use of causal analysis tools, the importance of understanding the assumptions underlying such methods has increased. Methods and estimates are occasionally stretched beyond the limits of the underlying assumptions. This has increased the need for a thorough understanding of what assumptions are necessary to identify causal estimates outside of a purely experimental framework. Additionally, it has lead to a need for validation tests that allow researchers to provide sound evidence that estimates are unbiased./nThis dissertation focuses on one area, methods for increasing the external validity of experimental estimates, of interest to researchers and policy makers alike. This problem is addressed from multiple angles, both theoretical, practical, and from a design perspective. First, I outline the assumptions necessary to identify population treatment effects from experimental data. I then discuss a new estimating strategy for testing the key identifying assumption central to most causal methods, the notion of exchangeability. This new method leverages tests of equivalence to redefine the approach to validation tests such as balance and placebo tests. Finally, a new approach to improving the underlying data from which we explore questions and estimate quantities of interest is provided. This new method, response rate sampling, allows researchers to collect more representative survey data. Combined, these tools will allow researchers to move more fluidly between experimental and observational estimates.

Advisor: Sekhon, Jasjeet
Automatic Mapping of Real Time Radio Astronomy Signal Processing Pipelines onto Heterogeneous Clusters

Traditional radio astronomy instrumentation relies on custom built designs, specialized for each science application. Traditional high performance computing (HPC) uses general purpose clusters and tools to parallelize the each algorithm across a cluster. In real time radio astronomy processing, a simple CPU/GPU cluster alone is insufficient to process the data. Instead, digitizing and initial processing of high bandwidth data received from a single antenna is often done in FPGA as it is infeasible to get the data into a single server./nChoosing which platform to use for different parts of an instrument is a growing challenge. With instrument specifications and platforms constantly changing as technology progresses, the design space for these instruments is unstable and often unpredictable. Furthermore, the astronomers designing these instruments may not be technology experts, and assessing tradeoffs between different computing architectures, such as FPGAs, GPUs, and ASICs and determining how to partition an instrument can prove difficult. In this work, I present a tool called Optimal Rearrangement of Cluster-based Astronomy Signal Processing, or ORCAS, that automatically determines how to optimally partition an instrument across different types of hardware for radio astronomy based on a high level description of the instrument and a set of benchmarks./nIn ORCAS, each function in a high level instrument gets profiled on different architectures. The architectural mapping is then done by an optimization technique called integer linear programming (ILP). The ILP takes the function models as well as the cost model as input and uses them to determine what architecture is best for every function in the instrument. ORCAS judges optimality based on a cost function and generates an instrument design that minimizes the total monetary cost, power utilization, or another user-defined cost.

Advisor: Wawrzynek, John
Werthimer, Daniel
Community Cellular Networks

There are over six billion active cellular subscribers, spending a total of over a trillion dollars a year on communications. Despite this, hundreds of millions of people, primarily in rural areas, are/nstill without network connectivity. There are two primary reasons for this: First, it is too expensive for traditional carriers to install equipment in far flung regions with small markets. Second, traditional carriers are the only organizations allowed to provide coverage; local/npeople cannot./nTo bring network connectivity to these remaining hundreds of millions of people, we introduce the concept of community cellular networks: small-scale, locally operated networks independent from traditional telecommunication firms. In support of these networks, we also introduce virtual coverage, a novel power saving mechanism in GSM networks. Virtual coverage allows us to reduce the total install cost of the network to the point where individual operators/ncan run their own full-scale telecommunication firms./nWe deployed the first community cellular network in the community of Desa, in rural Papua, Indonesia. This community of approximately 1500 people is far from existing network coverage. We developed numerous services for the community including a credit system, singing competition, and others. The network also made use of virtual coverage./nWe evaluated community cellular and virtual coverage through this real-world installation in Desa. Over a six-month period, we saw over 100000 communications, reduced the night power draw by 56.6%, and generated over US$5000 in revenue for the local operator. This/nnetwork is sustainable, generating over US$368 per month in profit for the local operator, even assuming complete financing of the install. We interviewed users of the system, discovering that most of their communication is with family and friends in other Indonesian areas. Lastly, we show that this network is significantly more locally-focused than a traditional firm in sub-Saharan Africa./nThese results validate the community cellular model. We explore future work needed for this model to flourish, including more technological innovations in power saving and alternative models for regulating these small networks.

Advisor: Brewer, Eric
Parikh, Tapan
Exploring the Limits of Dropwise Condensation on Nano-structured Surfaces

Within the types of condensation that can form on a surface, dropwise condensation has been previously shown to produce condensation heat transfer coefficients up to an order of magnitude greater than film condensation. Among dropwise condensation investigations, it has also been shown that smaller droplets result in higher heat transfer coefficients. An area that is currently under investigation within condensation advancements is creating superhydrophobic surfaces that can sustain smaller droplets during condensation. However, as droplet diameters are reduced to sizes comparable to the flow's mean free path, various mechanisms are expected to affect transport as the flow transitions from a continuum to free molecular flow: non-continuum transport effects, curvature effects on surface tension and on saturation conditions, and interactions with nearby droplets./nIn this dissertation, we investigate the limits of heat transfer performance on surfaces that strive to sustain dropwise condensation for smaller droplets. We explore and compare the limitations of dropwise condensation as mean droplet sizes are reduced to micro and nanoscales using three different models: one that uses an approximation for micro and nanoscale transport on an array of droplets, one that uses the DSMC method to simulate transport on a single droplet, and a third model that uses the DSMC method to simulate transport on an array of droplets./nWe found the three different models to show similar trends; dropwise condensation heat transfer coefficients increased as droplet sizes were reduced, but only up to a certain point where non-continuum transport and curvature effects became significant. For pure steam condensing on a cold wall at standard atmospheric condition with 3 degrees Celsius of subcooling, drop- wise condensation heat transfer coefficients were found to peak when droplets approached diameters near 200 nm. The effects of varying contact angle, thermal accommodation, pres- sure, amount of subcooling, spacing between droplets, and introduction of noncondensible particles into the system are also explored and discussed in detail.

Advisor: Carey, Van P
Engineering cellulases for enhanced degradation of insoluble substrates

There is tremendous social and political interest in the production of sustainable and carbon neutral liquid fuels that can meet our transportation energy demands. Second-generation biofuels, derived from cellulosic non-edible plant matter (biomass), represent a possible solution to this issue. The US Department of Energy and the Department of Agriculture estimate that the US can produce the energy equivalent 42 percent of the total US annual transportation consumption from cellulosic biomass, without having a grossly negative impact on food supply./nBiomass can be deconstructed to glucose, a type of sugar that can be fermented to make the biofuels. Glucose monomers are located within a strong crystalline polymer called cellulose, which is surrounded by other complex polymeric structures called hemicellulose and lignin. In order to obtain this sugar the biomass therefore has to pass through mechanical, physicochemical, and enzymatic treatments. The mechanical and physicochemical stages of the process increase the accessibility of cellulose to cellulolytic enzymes responsible of converting the cellulose to glucose. Optimization of these enzymes can have a significant impact on the economics and feasibility of biofuels. A detailed understanding of how carbohydrate-binding domains (CBMs) increase the activity of cellulases remains elusive. We have completed a series of studies that shed light on how certain CBMs affect the activity of cellulases from three different perspectives:/n1) Specific enzyme-substrate interactions: Neutron reflectivity is used to analyze the effect of endocellulases on cellulose film density and thickness. Two endocellulases, each tethered or untethered to a single CBM, are compared in this study./n2) General synergy between CBMs from three different families and a specific cellulase: We set out to determine if there is any correlation between CBM family and activity level or substrate preference, as measured by enhanced activity of a single cellulase. From a library of chimeric enzymes tested for activity on crystalline and non-crystalline substrates, we chose to examine in more detail three enzymes that exhibited approximately equal activity enhancements on amorphous cellulose. These chimeras consisted of a model endocellulase tethered to a CBM belonging to family one, two or three. Neutron reflectivity was used to study the interaction of the three chimeric endocellulases with amorphous cellulose model films./n3) The effect of enzymatic ratios in simple cellulolytic cocktails and the impact of CBM-containing enzymes on those ratios: We focused on the optimization of simple cellulolytic cocktails for real-world operational conditions. With basic conditions established, optimization is achieved by changing the ratios of the different components within the cocktail. The resulting optimal ratios and efficiency of glucose release was examined for cocktails comprising either commercial enzymes or enzymes identified to be active under extreme, but industrially relevant conditions.

Advisor: Tullman-Ercek, Danielle
Blind and Deaf to Acceptance: The Role of Self-Esteem in Capitalizing on Social Acceptance

Across two studies, we evaluated whether people with low self-esteem are less likely to capitalize on, or take full advantage of, their romantic partners' accepting behaviors. We conceptualized capitalization as the tendency to perceive acceptance when it occurs, and to experience positive changes in affect and relationship satisfaction when acceptance is perceived. We found that participants with low self-esteem under-perceived their partners' acceptance, both in daily life and in the laboratory. When these behaviors were noticed, participants with low self-esteem experienced smaller, and temporally shorter, boosts in positive affect and relationship satisfaction than participants with high self-esteem. Moreover, the degree to which participants noticed social acceptance in daily life predicted relationship closeness over time. These results generally supported our predictions, and suggest that targeting responses to social acceptance may be an important point of intervention for future studies evaluating ways to improve self-esteem.

Advisor: Ayduk, Ozlem
Complex and p-adic computations of Chow-Heegner points

In this work we delve into the theory of Chow-Heegner points, establishing some of their basic properties and developing two methods for their explicit computation. Chapters 1 and 2 cover the background material necessary for the later chapters. Chapter 3 gives several definitions of Chow-Heegner points and explores the specific setting of modular abelian varieties. Chapter 4 develops an algorithm for computing Chow-Heegner points via complex analytic methods, and Chapter 5 considers a corresponding algorithm in the p-adic setting.

Advisor: Ribet, Kenneth
Design and Analysis of Small-Scale Solar Thermal Combined Heat and Power Systems

Distributed solar thermal combined heat and power is an area where there is potential for significant innovation to reduce the cost of solar energy. Two areas for innovation were explored: reduced thermal losses in a novel dual-chamber absorber tube and parametric study for optimal efficiency of small-scale (5-10 kW) radial inflow turbines./nIncreasing the peak temperature in solar thermal systems typically increases the cycle thermal efficiency. However, the outer wall temperature of the absorber tube also increases causing greater thermal losses to the surroundings. A novel finned dual-chamber absorber tube design was presented as a possible solution. Fins attached to the outer wall could serve as a heat sink to send heat into the inner chamber. Computation modeling was validated by a reduced-scale experiment to the accuracy of the correlations used. From these models, it has been demonstrated that the heat loss to the environment from the outer wall of the absorber tube could be reduced by 10-60%. The best performance was found when water enters the outer chamber at the highest mass flow rate tested. This impressive improvement encourages further development of the dual chamber design./nOne of the primary obstacles of scaling down solar thermal technology for distributed power generation is finding an appropriate expander design. The radial inflow turbine was considered. A parametric study of seventeen input parameters was completed. Of these parameters, the mass flow rate, r2,hr2,t (ratio of rotor exit hub radius to rotor exit tip radius) and r2,tr1a (ratio of rotor exit tip to rotor inlet radius) had the greatest influence on the thermal efficiency of the system. Decreasing the mass flow rate both increased the turbine efficiency and increased the pressure drop across the turbine both of which enhanced the thermal efficiency. The optimized value of r2,hr2,t and r2,tr1a depended on the type of fluid. Wet fluids had an optimal performance with low values of r2,tr1a but high values of r2,hr2,t. Dry fluids had an optimal thermal performance with low values of both r2,hr2,t and r2,tr1a . Of the fluids studied it appears that dry fluids with low molecular mass and high critical temperature yielded the greatest thermal efficiency. Such fluids typically have low viscosity, allowing there to be less frictional losses in the turbine leading to better thermal efficiencies. Unfortunately, these fluids also share the characteristic of being highly toxic. In order for the radial inflow turbine to scale with reasonable efficiency, a non-toxic dry fluid with low molecular mass and high critical temperature would need to be found.

Advisor: Carey, Van P
Optimizing Parallel Job Performance in Data-Intensive Clusters

Extensive data analysis has become the enabler for diagnostics and decision making in many modern systems. These analyses have both competitive as well as social benefits. To cope with the deluge in data that is growing faster than Moore's law, computation frameworks have resorted to massive parallelization of analytics jobs into many fine-grained tasks. These frameworks promised to provide efficient and fault-tolerant execution of these tasks. However, meeting this promise in clusters spanning hundreds of thousands of machines is challenging and a key departure from earlier work on parallel computing./nA simple but key aspect of parallel jobs is the all-or-nothing property: unless all tasks of a job are provided equal improvement, there is no speedup in the completion of the job. The all-or-nothing property is critical for the promise of efficient and fault-tolerant parallel computations on large clusters. Meeting this promise in clusters of these scales is/nchallenging and a key departure from prior work on distributed systems. This work examines the execution of a job from first principles and propose techniques spanning the software stack of data analytics systems such that its tasks achieve homogeneous performance while overcoming the various heterogeneities./nTo that end, we will propose techniques for (i) caching and cache replacement for parallel jobs, which outperforms even Belady's MIN (that uses an oracle), (ii) data locality, and (iii) straggler mitigation. Our analyses and evaluation are performed using workloads from Facebook and Bing production datacenters. Along the way, we will also describe how we broke the myth of disk-locality's importance in datacenter computing.

Advisor: Stoica, Ion
Essays on Environmental and Resource Economics

This dissertation consists of three applied essays on environmental and resource economics. The essays study consumer and local government responses to exogenous shocks: randomized environmental messages, variation in international mineral prices and a widely publicized food-borne disease outbreak. In particular, this dissertation focuses in three broad areas: (i) investigating whether environmental messages can increase energy efficient technology adoption by poor populations and understanding the characteristics of the individuals who respond to these messages, (ii) testing whether increases in municipal income translate into additional environmental investments and policies in developing countries and, (iii) studying the role of food borne disease outbreaks on consumer purchases and preferences.

Advisor: Berck, Peter