VictorJuiz/thesis huggingface dataset:
Earthquake Surface Fault Rupture Interaction with Building Foundations

Recent earthquakes have provided numerous examples of the devastating effects of earthquake surface fault rupture on structures. Several major cities are built in areas containing active faults that can break the ground surface (e.g., Los Angeles, Salt Lake City, San Diego, San Francisco, and Seattle). Along with the often spectacular observations of damage, examples of satisfactory performance of structures were also observed. These examples of satisfactory performance indicate that similar to other forms of ground failure, effective design strategies can be developed to address the hazards associated with surface fault rupture. However, at present, no design guidance exists for implementing many of the potential strategies for building near faults./nTo address this issue, a comprehensive set of numerical simulations, which were initially validated with centrifuge test results, has been undertaken to analyze potential design strategies for building in the vicinity of active faults. The numerical simulations capture fully this problem as a soil-structure-fault interaction problem where the influence of the structure has been explicitly included. A modified nonlinear, effective stress, elasto-plastic soil constitutive model has been developed and implemented in an explicit finite-difference framework to capture the soil and structural responses to fault rupture./nFor the first time, the effects of prior earthquake ruptures through soil (e.g., pre-existing shear bands and the in situ stress state) were investigated. Additionally, the effects of fault type on soil response was analyzed and was found to be primarily a result of varying stress paths in normal, reverse, and vertical faults. The effects of dynamic soil-fault-structure interaction were analyzed in a systematic manner for the first time and procedures to account for these effects were developed./nHazard mitigation strategies were developed and systematically evaluated and compared. Three main categories of fault-resistant design were identified: (1) spreading fault displacement over a large area, such as with engineered fill; (2) enabling the structure to respond with rigid-body movement, e.g., by using a stiff mat foundation; and (3) diverting fault rupture through soil using stiff structural elements or by strengthening the foundation soil. These strategies were found to be effective at minimizing structural damage during surface fault rupture events. Their use allows for improved designs and retrofits in the active fault regions, which reduce risk while preserving design flexibility.

Advisor: Bray, Jonathan D
Shapes, Paint, and Light

A fundamental problem in computer vision is that of inferring the intrinsic, 3D structure of the world from flat, 2D images of that world. Traditional methods for recovering scene properties such as shape, reflectance, or illumination rely on multiple observations of the same scene to overconstrain the problem. Recovering these same properties from a single image seems almost impossible in comparison --- there are an infinite number of shapes, paint, and lights that exactly reproduce a single image. However, certain explanations are more likely than others: surfaces tend to be smooth, paint tends to be uniform, and illumination tends to be natural. We therefore pose this problem as one of statistical inference, and define an optimization problem that searches for the most likely explanation of a single image. Our model, which we call ``SIRFS'', can be viewed as a superset of several classic computer vision problems (shape-from-shading, intrinsic images, color constancy, illumination estimation, etc) and outperforms all previous solutions to those constituent problems./nThough SIRFS performs well on images of segmented objects, it performs poorly on images of natural scenes, which contain occlusion and spatially-varying illumination. We therefore additionally present Scene-SIRFS, a generalization of SIRFS in which we have a mixture of shapes and a mixture of illuminations, and those mixture components are embedded in a ``soft'' segmentation of the input image. We additionally use the noisy depth maps provided by RGB-D sensors (in this case, the Kinect) to improve shape estimation.

Advisor: Malik, Jitendra
Variations on Quantum Geometry

This dissertation explores various aspects of quantization and geometry. In particular, we analyze the ground states of a two-dimensional sigma-model whose target space is an elliptically fibered K3, with the sigma-model compactified on S1 with boundary conditions twisted by a duality symmetry. We show that the Witten index receives contributions from two kinds of states: (i) those that can be mapped to cohomology with coefficients in a certain line bundle over the target space, and (ii) states whose wave-functions are localized at singular fibers. We also discuss the orbifold limit and possible connections with geometric quantization of the target space. We also provide a deformation quantization approach for differential forms on symplectic manifolds. After a description of the Z-graded differential Poisson algebra, we introduce a covariant star product for exterior differential forms and give an explicit expression for it up to second order in the deformation parameter, in the case of symplectic manifolds. The graded differential Poisson algebra endows the manifold with a connection, not necessarily torsion-free, and places upon the connection various constraints.

Advisor: Zumino, Bruno
In-situ microscopy of the first-order magnetic phase transition in FeRh thin films

Simple ferromagnetic (FM) and antiferromagnetic (AF) materials such as Fe and Cr become paramagnetic when heated above some critical temperature, in what is known as a second-order phase transition. Less usual magnetic transitions are found in the magnetic world, for example a first-order magnetic phase transition from AF to FM with increasing temperature. Equiatomic FeRh has been known to exhibit such a transition for over 50 years, with a transition temperature slightly above room temperature. Interest in this material has been renewed in the recent years due to its potential application for heat-assisted magnetic recording, as well as a test system for fundamental studies of the physics of magnetic phase transitions. Similarly to crystallization, this AF-FM transition is expected to proceed by nucleation of magnetic domains but the features of the first-order hysteretic transition have been difficult to study with macroscopic measurements and very few microscopic studies have been performed./nIn this work, FeRh thin films were synthesized by magnetron sputtering and structurally and magnetically characterized. A membrane-based heating device was designed to enable temperature-dependent microscopy measurements, providing a thermally uniform and well-controlled sample area. Synchrotron x-ray magnetic microscopy was used to study the temperature-driven AF-FM phase transition in epitaxial FeRh thin films in zero field. Using magnetic microscopy with x-ray magnetic circular dichroism, the different stages of nucleation, growth and coalescence of FM domains were observed across the transition and details of the nucleation were identified. The FM phase nucleates into single domain/nislands and the width of the transition of the individual nuclei upon heating is sharper than that of the macroscopic transition. Using magnetic microscopy with x-ray magnetic linear dichroism, the evolution of the AF phase was studied. Differences in the morphology of AF and FM phases were found, with the AF phase having a smaller feature size limited by defects. Finally, interfacial FM at the interface with capping layers is due to an alloying effect with a third metallic element that stabilizes the FM phase at room temperature by lowering the transition temperature.

Advisor: Hellman, Frances
Controlling Energy-Efficient Buildings in the Context of Smart Grid: A Cyber Physical System Approach

The building sector is responsible for about 40% of energy consumption, 40% of greenhouse gas emissions, and 70% of electricity use in the US. Over 50% of the energy consumed in buildings is directly related to space heating, cooling and ventilation./nOptimal control of heating, ventilation and air conditioning (HVAC) systems is crucial for reducing energy consumption in buildings. We present a physics-based mathematical model of thermal behavior of buildings, along with a novel Parameter Adaptive Building (PAB) model framework to update the model parameters, as new measurements arrive, to reduce the model uncertainties./nWe then present a Model Predictive Control (MPC), and a Robust Model Predictive Control (RMPC) algorithm and a methodology for selecting a controller type, i.e. RMPC or MPC, versus Rule Based Control (RBC) as a function of model uncertainty./nWe then address the Cyber-Physical" aspect of a building HVAC system in the design flow. We present a co-design framework that analyzes the interaction between the control algorithm and the embedded platform through a set of interface variables, and demonstrate how the design space is explored to optimize the energy cost and monetary cost, while satisfying the constraints for occupant comfort level./nThe last part of this dissertation is centered on the role of smart buildings in the context of the smart grid. Commercial buildings have inherent flexibility in how their HVAC systems consume electricity. We first propose a means to define and quantify the flexibility of a commercial building. We then present a contractual framework that could be used by the building operator and the utility company to declare flexibility on one side and reward structure on the other side. We also present a control mechanism for the building to decide its flexibility for the next contractual period to maximize the reward. We also present a Model Predictive Control (MPC) scheme to direct the ancillary service power flow from buildings to improve upon the classical Automatic Generation Control (AGC) practice. We show how constraints such as slow and fast ramping rates for various ancillary service providers, and short-term load forecast information can be integrated into the proposed MPC framework. Finally, results from at-scale experiments are presented to demonstrate the feasibility of the proposed algorithm.

Advisor: Sangiovanni-Vincentelli, Alberto
Borrelli, Francesco
Longitudinal Effects of Parent School-Based Involvement on Child and School Outcomes

Parental school-based involvement (school PI) has been widely embedded in federal law and policy as a main target for school reform and educational equality. However, previous scholarship hasn't reached the consensus about the effectiveness of parent involvement in school-sponsored activities. Considering that federal, state-level education policy has put huge efforts and resources to promote parents' active school participation, there is an imperative need to investigate whether school PI is truly beneficial to child development. Furthermore, prior researchers revealed that the influence of PI on student achievement varies by social class (Desimone, 1999). Some have questioned the way existing school PI practices reinforce inequality and disadvantage for poor parents. Thus, the current study aimed to examine the relative impact on child and school-level outcomes of three types of school PI - involvement directed at their own child (private good PI), involvement to improve the school as a whole (public good PI), and involvement in parent networks (parent network), across SES groups./nThe key finding is that school PI brought diverse benefits for educational outcomes, but the payoff of school PI varies considerably by child's grade, types of school PI, outcomes of interest, and family/school SES. Children whose parents got highly involved in private good PI reported rapid growth rates in math and reading achievement so that they significantly outperformed their peers at the end of elementary years. Children whose parents actively participated in public good activities and formed social networks with other parents reported higher math, but not reading, achievement at each grade, but no growth pattern over time. In addition, children whose parents reported high levels of involvement in all three types of school PI were rated socially better-adjusted and well-behaved by their teachers at each grade. Regarding school-level benefits, schools where a large numbers of parents were involved in three types of school PI were likely to report higher school-level achievement and more supportive school climate than their counterparts./nNotably, the positive relations of school PI to educational outcomes were moderated by family and school SES. Students' from high SES families obtained more benefits from their parents' participation in public good and private good PI activities than did students from low SES families. Similarly, high-SES schools were more likely to improve their school climate when high percentage of parents in schools was engaged with public good PI activities. However, school-mean private good PI and network worked more favorably for low-SES schools.

Advisor: Holloway, Susan D.
Quantum Monte Carlo Simulations of Ultracold Bosons in a Double Well

We present path integral ground state (PIGS) quantum Monte Carlo calculations for the ground state (T = 0) properties of repulsively interacting bosons in a three-dimensional external double well potential over a range of interaction strengths and potential parameters. We focus our calculations on ground state number statistics and the one-body density matrix in order to understand the level of squeezing and fragmentation that the system exhibits as a function of interaction strength, and we compare our PIGS results to both a standard and an improved two-mode model and a recently-proposed eight-mode model. In general, the various models agree with the PIGS simulations for weak interactions, but the full quantum Monte Carlo treatment is required to correctly predict the amount of squeezing and fragmentation exhibited for strong interactions. One novel and somewhat surprising result from our simulations involves the relationship between squeezing and interaction strength: rather than a monotonic relationship between these quantities, we find that for certain double well barrier heights the squeezing increases as a function of interaction strength until it reaches a maximum, after which it decreases again. We also see a similar relationship between fragmentation and interaction strength. We propose novel physical mechanisms to account for this behavior.

Advisor: Whaley, Birgitta
Budker, Dmitry
Essays in Energy Economics

In this dissertation I explore two aspects of the economics of energy. The first focuses on consumer behavior, while the second focuses on market structure and firm behavior./nIn the first chapter, I demonstrate evidence of loss aversion in the behavior of households on two critical peak pricing experimental tariffs while participating in the California Statewide Pricing Pilot. I develop a model of loss aversion over electricity expenditure from which I derive two sets of testable predictions. First, I show that when there is a higher probability that a household is in the loss domain of their value function for the bill period, the more strongly they cut back peak consumption. Second, when prices are such that households are close to the kink in their value function - and would otherwise have expenditure skewed into the loss domain - I show evidence of disproportionate clustering at the kink. In essence this means that the occurrence of critical peak days did not only result in a reduction of peak consumption on that day, but also spilled over to further reduction of peak consumption on regular peak days for several weeks thereafter. This was similarly true when temperatures were high during high priced periods. This form of demand adjustment resulted in households experiencing bill-period expenditures equal to what they would have paid on the standard non-dynamic pricing tariff at a disproportionate rate. This higher number of bill periods with equal expenditure displaced bill periods in which they otherwise would have paid more than if they were on standard pricing./nIn the second chapter, I explore the effects of two simultaneous changes in minimum energy efficiency and Energy Star standards for clothes washers. Adapting the Mussa and Rosen (1978) and Ronnen (1991) second-degree price discrimination model, I demonstrate that clothes washer prices and menus adjusted to the new standards in patterns consistent with a market in which firms had been price discriminating. In particular, I show evidence of discontinuous price drops at the time the standards were imposed, driven largely by mid low efficiency segments of the market. The price discrimination model predicts this result. On the other hand, under perfect competition, prices should increase for these market segments. Additionally, new models proliferated in the highest efficiency market segment following the standard changes. Finally, I show that firms appeared to use different adaptation strategies at the two instances of the standards changing.

Advisor: Berck, Peter
Fowlie, Meredith
Quantum Gravity in Three Dimensions from Higher-Spin Holography

In this thesis, I explore various aspects of quantum gravity in three dimensions from the perspective of higher-spin holography in anti-de Sitter spacetime. The bulk theory is a higher-spin Vasiliev gravity theory of which topological sector can be described by a Chern-Simons/ntheory equipped with some suitable Lie (super-)algebra, whereas the boundary conformal field theory is conjectured to be a coset minimal model which contains W symmetries. I present new black hole solutions and investigate the thermodynamics of these solutions, in/nparticular, I establish a relationship among black hole thermodynamics, asymptotic symmetries and W algebras. I also construct new conical defect solutions, supersymmmetric RG flow solutions in the bulk gravity theories, and present the bulk-boundary propagator for scalar elds interacting with a higher-spin black hole. The main examples used in this thesis are illustrated in the framework of SL(N) and SL(N|N-1) Chern-Simons theories, and I point out how these new solutions can be used to yield some insights into the nature of quantum gravity.

Advisor: Ganor, Ori
Bureaucracy in a Network and Congressional Delegation

If there is no expert but bureaucracy in a policy area, expertise may be sufficient for an agency to acquire its discretion. However, it is hard for an agency as an expert to have monopolistic status in any policy area, due to the growth of interest groups. Delegation in recent decades depends not only on its expertise, but also on the other bureaucratic capability to affect the behaviors of the outside experts. Even the most expert agencies cannot maintain their discretionary authorities without sufficient political capacities to affect the behaviors of interest groups. In particular, "brokerage capacity" that allows agencies to link interest groups and to resolve their interest conflicts, has become important in bureaucratic discretion. By mediating conflicts of interest and minimizing unnecessary contingencies, agencies are able to reduce interest groups' incentives to provide information to the legislature, thereby indirectly affecting legislators' decisions on delegation and oversight.

Advisor: Gailmard, Sean
Ansell, Christopher
Program Implementation in the Prison System: An Organizational Study of the Chronic Care Model Program

This study provides evidence of a successful implementation of a not-for-profit operational model within a public setting. The federal government placed a receiver in charge of improving health care within the California Department of Corrections and Rehabilitation. To achieve the receivership's goals, a chronic care model from the not-for-profit sector was selected and implemented to improve the delivery of health care to inmates. The data suggest that operational programs developed outside of the government setting can fit the public-sector context with considerable and carefully selected modifications. This study also finds that focusing managerial behavior on program implementation details is also required for successful implementation./nThese results may be generalizable to other settings in which private-sector models are selected for implementation in public-sector agencies. Policy makers and program administrators concerned with improving health care within correctional settings can use the framework for program implementation developed within this study.

Advisor: LaPorte, Todd
Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency

The ever-present need for reducing greenhouse gas emissions associated with transportation motivates this investigation of a novel ignition technology for internal combustion engine applications. Advanced engines can achieve higher efficiencies and reduced emissions by operating in regimes with diluted fuel-air mixtures and higher compression ratios, but the range of stable engine operation is constrained by combustion initiation and flame propagation when dilution levels are high. An advanced ignition technology that reliably extends the operating range of internal combustion engines will aid practical implementation of the next generation of high-efficiency engines. This dissertation contributes to next-generation ignition technology advancement by experimentally analyzing a prototype technology as well as developing a numerical model for the chemical processes governing microwave-assisted ignition./nThe microwave-assisted spark plug under development by Imagineering, Inc. of Japan has previously been shown to expand the stable operating range of gasoline-fueled engines through plasma-assisted combustion, but the factors limiting its operation were not well characterized. The present experimental study has two main goals. The first goal is to investigate the capability of the microwave-assisted spark plug towards expanding the stable operating range of wet-ethanol-fueled engines. The stability range is investigated by examining the coefficient of variation of indicated mean effective pressure as a metric for instability, and indicated specific ethanol consumption as a metric for efficiency. The second goal is to examine the factors affecting the extent to which microwaves enhance ignition processes. The factors impacting microwave enhancement of ignition processes are individually examined, using flame development behavior as a key metric in determining microwave effectiveness./nFurther development of practical combustion applications implementing microwave-assisted spark technology will benefit from predictive models which include the plasma processes governing the observed combustion enhancement. This dissertation documents the development of a chemical kinetic mechanism for the plasma-assisted combustion processes relevant to microwave-assisted spark ignition. The mechanism includes an existing mechanism for gas-phase methane oxidation, supplemented with electron impact reactions, cation and anion chemical reactions, and reactions involving vibrationally-excited and electronically-excited species. Calculations using the presently-developed numerical model explain experimentally-observed trends, highlighting the relative importance of pressure, temperature, and mixture composition in determining the effectiveness of microwave-assisted ignition enhancement.

Advisor: Chen, Jyh-Yuan