VictorJuiz/thesis huggingface dataset:
Efficient and scalable simulation of solids and fluids [electronic resource]

This thesis considers the numerical simulation of rigid and deformable bodies, as well as compressible fluids. We consider each of these types of simulations independently, and in particular we focus on what it takes to make these simulations both efficient and scalable. First, we develop a robust parallelized method for simulating cloth and we demonstrate simulations consisting of up to 2 million triangles. This added level of detail allows us to achieve high detailed folds and wrinkles. We propose a robust history-based repulsion/collision framework where repulsions are treated accurately and efficiently on a per time step basis. Distributed memory parallelism is used for both time evolution and collisions and we specifically address Gauss-Seidel ordering of repulsion/collision response. Next, we propose a method for alleviating the stringent CFL condition imposed by the sound speed in simulating inviscid compressible flow with shocks, contacts and rarefactions. Our method is based on the pressure evolution equation, so it works for arbitrary equations of state, chemical species, etc. The relaxed CFL condition allows us to simulate shocks, contacts and rarefactions accurately while taking much larger time steps than before. Then, we turn to the simulation of rigid bodies, where we present an algorithm for conserving energy and momentum when advancing rigid body orientations. Furthermore, we develop a technique for clamping energy gain during contact and collisions. Together, these methods allow us to prevent energy increase during rigid body simulations, regardless of the time step size. This allows us to reduce the computation needed while still producing stable and physically plausible simulations. We also introduce a technique for fast and realistic fracture of rigid bodies using a novel collision-centered prescoring algorithm. Finally, we extend the use of energy preservation techniques to the simulation of deformable bodies, again with the goal of reducing the cost of these simulations. We propose a new spring that, in one spatial dimension, gives the exact solution regardless of the size of the time step chosen. In multiple spatial dimensions, the problem becomes nonlinear because the direction of the spring changes over time, and thus we propose an iterative approach. Then, we consider the simulation of more complicated elements such as triangles, tetrahedra, and finally full meshes and propose a novel technique that allows us to cut the iterative approach short and instead apply a final correction globally to the mesh.

Advisor: Fedkiw Ronald P.
Chhugani Jatin advisor. Thesis advisor
Hanrahan P. M. (Patrick Matthew) advisor. Thesis advisor
Electrical and optical characterization of molecular junctions [electronic resource]

Electronic transport through molecules has been intensively studied in recent years, due to scientific interest in fundamental questions about charge transport and the technological promise of nanoscale circuitry. A variety of experimental platforms have been developed to electronically probe molecular junctions. However, it remains challenging to fabricate reliable electronic contacts to molecules, and the vast majority of molecular electronic architectures are not amenable to standard characterization techniques, such as optical spectroscopy. Interesting phenomena like switching and rectification are observed in molecular junctions. However, due to limited quantitative information about the junction, the mechanism remains unknown and many fundamental questions about electronic transport remain unanswered. The first part of the thesis will introduce the fabrication of Metal-Insulator-Metal (MIM) cross bar junctions using soft deposition technique. In this method, we softly deposit the premade metal contacts that are being supported with a polymer backing layer onto the organic layer. Using this method, we can efficiently fabricate large area, non-shorting devices, which are required for optical characterization of the molecular junctions. Having established a means of fabricating reliable molecular devices, we have investigated the switching mechanism in molecular junctions based on n-type semiconductor Perylene tetracarboxylic diimide (TE-PTCDI) molecules. Using Surface Plasmon Resonance Spectroscopy (SPRS) we have been able to perform simultaneous optical-electrical measurements to study the molecular behavior quantitatively. Using in- situ optical spectroscopy on active molecular junctions, we find that only a small fraction of the molecules are actually switching in the junction. Next, metal filament formation, a common phenomenon in thin film devices has been investigated. Metal filaments are observed to lead to non-molecular conductance variations in molecular junctions. Employing electrical and optical methods, the possible mechanisms responsible for the formation of metal filaments in the junction were studied. Finally, I present the results of our studies on the molecular rectification in C60- diamondoid hybrid molecules in large area junctions, as well as in smaller ensemble of molecules.

Keywords: Chemical Engineering
Advisor: Bent Stacey primary advisor. Thesis advisor
Melosh Nicholas A. primary advisor. Thesis advisor
Bao Zhenan advisor. Thesis advisor
Electroabsorption mechanisms in germanium quantum well material [electronic resource]

One possible solution to make viable optoelectronic modulators that meet strict targets down to the scale of on-chip communication is to use germanium-rich materials. Ge/SiGe quantum wells grown on silicon substrates provide the strongest mechanism, the quantum-confined Stark effect (QCSE), and thereby can meet the strictest requirements for optical interconnects, including CMOS-compatibility. Using such a strong effect, Ge-based modulators can be ultra-compact, ultralow-power, large bandwidth and high-speed, making them a strong contender for the future of optoelectronic device integration to solve the bottleneck problem. In this thesis, we will discuss the physical properties of the Ge and SiGe material system then present designs of optoelectronic modulators at the important 1310 nm and 1550 nm communication wavelengths using a program we developed called the Simple Quantum Well Electroabsorption Calculator (SQWEAC). SQWEAC takes the important physical mechanisms present, such as QCSE and indirect absorption, to predict the electroabsorption profile of Ge-based quantum wells. QCSE was experimentally determined on a wide range of samples to show the predictive powers of SQWEAC. Additionally, indirect absorption was also experimentally determined to optimize the physical model for these Ge quantum well devices. In being able to design both 1310 nm and 1550 nm devices using this Ge material system, we provide a platform for designing optoelectronic devices that are Si CMOS compatible and operate over a wide range of wavelengths. These modulators have the capability of providing the large density of information at very low energies per bit required for future interconnect technologies.

Keywords: Electrical Engineering
Advisor: Harris J. S. (James Stewart)
Miller D. A. B. primary advisor. Thesis advisor
Saraswat Krishna advisor. Thesis advisor
Electronic structure factors in the reactivity of strained and ligand modified platinum surfaces [electronic resource]

The ultimate goal in catalytic design is to have complete synthetic control of the material properties that determine the reactivity. Catalysts that consist of two metals (bimetallic) allow for potential greater reactivity and more flexible design. There are two factors that contribute to the modification of the electronic properties of a metal in a bimetallic surface: strain and ligand effects. Strain effects are due to a modified atomic arrangement of surface atoms in terms of distances and may include compressed or expanded lattices. Ligand effects are caused by chemical interaction of a metal atom with other metals in its vicinity. Having complete control of the electronic properties of a particular bimetallic surface, however, remains challenging. In this thesis, we have focused on using the strain and ligand effects to controllably tune the electronic structure of a metal surface and hence the metal-adsorbate chemical bond. We have investigated the electronic factor in the modified reactivity of epitaxially strained (Pt/Cu and Pt/Ag) and ligand modified (Pt-3d-Pt, 3d = Fe, Co, Ni) platinum surfaces towards the adsorption of oxygen. The electronic nature of chemisorbed oxygen on these surfaces was studied by probing occupied and unoccupied Pt-O states using synchrotron based x-ray emission spectroscopy (XES) and x-ray absorption spectroscopy (XAS), respectively. Using XES and XAS we are able to study the electronic states relevant for surface chemical bonding. For each surface structure studied, we observed significant perturbation in the valence electronic structure of adsorbed oxygen. Observed results are discussed within the framework of the d-band model -- a theoretical tool for predicting the adsorption properties of transition metal surfaces based on the average energy of the d-band.

Keywords: Physics.
Advisor: Nilsson Anders
Jaramillo Thomas Francisco advisor. Thesis advisor
Manoharan Harindran C. (Harindran Chelvasekaran)
Embodied experiences in immersive virtual environments [electronic resource] : effects on pro-environmental attitude and behavior

Immersive virtual environments (IVE) allow users experience vivid sensorimotor stimuli by digitally simulating sensorimotor information. As a result, users are able to embody experiences by seeing, hearing, and feeling realistic perceptual cues linked to those experiences. Embodied experiences are defined as being surrounded by simulated sensorimotor information in mediated environments that create the sensation of personally undergoing the experience at that moment. Based on the theoretical framework of embodied cognition, which stipulates a close connection between sensorimotor experiences of the body and mental schemas, the current dissertation studies demonstrated that embodied experiences in IVEs are able to influence attitudes and behaviors in the physical, non-mediated world. Two studies explored the effect of embodied experiences on proenvironmental attitude and behavior by having participants embody the experience of cutting down a redwood tree as a result of using non-recycled paper products. Focus was also placed on investigating individual elements of embodied experiences in IVEs and the moderating effect of individual differences in the capacity to feel presence, the perception that a mediated experience is real. In both studies, actual pro-environmental behavior is observed and compared to self-reports of attitude and behavioral intention.

Keywords: Communication
Advisor: Bailenson Jeremy primary advisor. Thesis advisor
Nass Clifford Ivar advisor. Thesis advisor
Reeves Byron
Wheeler S. Christian advisor. Thesis advisor
Emerging contaminants in ecosystems [electronic resource] : new challenges for water reuse implementation and mechanisms of perfluorochemical bioaccumulation

Technological innovations developed in response to pressing water supply needs in populated arid regions have led to the recovery of municipal wastewater for beneficial reuse worldwide. Yet even as rapid urbanization and severe droughts motivate wastewater reuse, new engineering and policy hurdles arise over public concerns and management challenges regarding the persistence of residual and byproduct pharmaceutical and industrial chemicals in treated municipal effluent. Bioaccumulation of synthetic organic chemicals in environments downstream of wastewater effluent discharge and recycled water use poses an ecological risk and introduces a potential pathway of human exposure to these contaminants. This dissertation assesses management challenges for water reuse implementation in Northern California; identifies opportunities of water reuse for ecosystem enhancement; explores the bioaccumulation of one class of persistent and toxic unregulated chemical contaminants, perfluoroalkyl acids (PFAAs); and evaluates mechanisms of bioaccumulation via an in-depth study of PFAA interactions with a model serum protein. This study provides context for issues surrounding chemicals of emerging concern (CECs) in recycled water. However, uncertainty regarding bioaccumulation of CECs from recycled water used for ecological enhancement or habitat creation remains a concern. Investigation of mechanisms influencing PFAA bioaccumulation provides insight into one class of CECs now detected in sensitive aquatic ecosystems and contributes to ongoing efforts to characterize the physiochemical properties of compounds used to replace long-chain perfluorinated chemicals.

Advisor: Luthy Richard G. primary advisor. Thesis advisor
MacManus-Spencer Laura (Laura Ann) advisor. Thesis advisor
Reinhard Martin
Emotion regulation for drivers [electronic resource] : an exploration of variables that promote positive emotional states and safe driving

Aggressive driving behaviors and driver frustration cause accidents and fatalities. Current attempts by academic researchers and car manufacturers to combat driver frustration focus on detecting the emotional state of the driver, and then determining an appropriate reaction to that state. Recognizing driver emotion through facial, voice, and physiological cues is a difficult task in the due to light, noise, and individual differences in driving and expressive styles. Similarly, responding appropriately to affective state of the driver requires a careful implementation of a voice interface. The work presented in this dissertation targets driver frustration but shifts the technology burden away from capturing driver state to understanding the environment. Instead of studying interfaces that require precise knowledge of the driver state, the dissertation work presented here assumes that drivers will experience negative emotion based on common frustrations (e.g., traffic, being cut-off), and that the technology to detect these conditions is currently available. The dissertation study examines the effects of emotion regulation type (cognitive reappraisal vs. suppression), source (self vs. other), and timing (pre-drive vs. in-drive) on driver performance and emotional states in a between-participants design (N = 112). Regulation type strongly affected driver attitudes, but only had a minimal effect on measures of driving behavior. This suggests that the demand of the driving environment Implications for application and theory are discussed.

Keywords: Communication
Advisor: Nass Clifford Ivar primary advisor. Thesis advisor
Bailenson Jeremy advisor. Thesis advisor
Gross James J.
Reeves Byron
Emotional bureaucracies [electronic resource] : sojourners and the politics of exclusion and inclusion in Israel

Abstract This dissertation argues that the decisions of Israeli state bureaucracies and the bureaucrats who work for them, regarding the deportation and naturalization of non-citizens are predicated on emotions as they are based on rules and regulations. I examine the way different Israeli state bureaucrats cope with the new waves of Gentile migration and with the challenges they pose to Jewish hegemony and Israeli sovereignty. I refer to this category of legal and illegal migrants as sojourners. This dissertation documents how feelings of state bureaucrats contribute to the shaping of Israel's de facto immigration regime and affect the lives of disempowered sojourners, and is based on ethnographic research from 2006-2007 with Israeli state bureaucrats of the Enforcement Unit and Visa Section of the Interior Ministry, adjudicators of the Detention Review Tribunal of the Justice Ministry, teachers and educators from the Public School, Bialik-Rogozin, and Israeli activists in NGOs that help sojourners. I demonstrate how different arms of the state have different worldviews, agendas, and goals and, thus, act in different ways toward sojourners. Through detention and deportation of sojourners as well as the rejection of sojourners' requests to naturalize in Israel, practices of exclusion and coercion cause suffering to undocumented non-citizens. To fathom how these processes operate, I study how state bureaucrats utilize diverse techniques of the self that enable them to maintain a positive self-image. I identify how the Israeli state is attempting to preserve Jewish majority and dominance in the face of an influx of migration. Thus, although the state has been granting citizenship status on the basis of conversion, marriage, and, for certain minors, living in Israel, the fundamental logics and politics of belongings remain relatively unchanged. The politics of belonging in Israel continue to emphasize the Arab-Jewish dichotomy and enmity overlooking sojourners as a negligible category. While initially "migrant workers" and "refugees" were seen as benign because they replaced the threatening Palestinians, they have not been accepted as having a right to remain permanently in Israel. Consequently, only a small number of sojourners who are conceived of as Israelis have been permitted to naturalize.

Keywords: Anthropology
Advisor: Ferguson James
Yanagisako Sylvia Junko
Beinin Joel
Empirical analysis of the organization of venture capital firms [electronic resource]

The dissertation consists of four chapters. Chapter 1 presents a model in which the internal organization and size of a professional partnership reflect contracting problems associated with collaboration between junior professionals and senior professionals. The model offers an economic rationale for the formation of multiple partners firms and demonstrates that when arrival of clients is uncertain they allow for better utilization of the juniors. Additionally, the analysis proposes a new approach to defining firm boundary which applies the incentive-system theory of the firm to the institutional context of professional partnerships. Chapter 2 studies the economic factors determining the size and composition of Venture Capital (VC) firms. I construct a panel data set documenting California VC firms' composition and investments and derive statistical relationships between firm size, its partners' experience, and industry trends. To interpret these empirical findings, the chapter considers several theories of partnership and firm size that vary in their economic rationale for forming firms and the factors determining equilibrium firm size. I discuss under what assumptions these theories can explain the empirical regularities and highlight methodological differences between these approaches. Chapter 3 quantitatively studies the surplus gains obtained by senior and junior partners who group together in a profit sharing partnership. The analysis addresses two empirical challenges: 1) the inability to observe and measure the surplus gains; and 2) the dependency of the gains on unobserved characteristics of the partners. I develop a model inferring the gains from the optimality of firms' decisions to recruit junior partners. The model exploits turnover and mobility of partners between firms to capture unobserved heterogeneity at the partner level. I estimate the model using a novel panel data set documenting California VC firms' composition, investments, and investment outcomes. Chapter 4 empirically studies whether mandatory unbundling delayed the deployment of DSL service by BellSouth by exploiting a law change in Kentucky and variation in access prices across markets. I find that deregulation in Kentucky triggered deployment, but I find no evidence that access prices affected deployment pace. An upper bound on the welfare loss due to late deployment in rural markets is

Keywords: Economics
Advisor: Einav Liran primary advisor. Thesis advisor
Bresnahan Timothy F. advisor. Thesis advisor
Leslie Phillip
The encoding of motion events in Chinese [electronic resource] : multi-morpheme motion constructions

This dissertation investigates the relative order of verbal morphemes that express motion in Chinese motion constructions consisting of multiple motion morphemes, e.g., the order of pao 'run' and jin 'enter' in the construction pao-jin fangjian run-enter room 'run into the room'. It argues that the order is predictable. Drawing on recent work on "scale structure", it divides Chinese motion morphemes into four types according to the type of scale each lexicalizes. Then it proposes a Motion Morpheme Hierarchy formed of these four types of motion morpheme that can be used to predict the order of motion morphemes. The hierarchy is supported by two extensive studies of multi-morpheme motion constructions using corpora of recent Chinese novels. In addition, the dissertation proposes a More Specific Constraint that explains why the Motion Morpheme Hierarchy emerges. The results of this study provides new insight into the distribution of motion morphemes in Chinese motion constructions and a more fine-grained analysis of the semantic relationships between the morphemes in these constructions; thus, it contributes to an increased understanding of how motion events are expressed in Chinese. The findings of this study may also illuminate the distribution of motion verbs in other languages, as well as constructions in domains other than motion.

Keywords: East Asian Languages and Cultures.
Advisor: Levin Beth primary advisor. Thesis advisor
Sun Chao primary advisor. Thesis advisor
Matsumoto Yoshiko
The encounter of knowledge [electronic resource] : technical ekphrasis Between Alexandria and Rome

ABSTRACT. This dissertation is a study of the techniques used to represent mechanical technology in ancient literature from Hellenistic Greece to late-ancient Rome. Ancient authors used a variety of verbal descriptive techniques, as well as visual elements like diagrams and tables, to bring their audience into imaginative contact with the artifact. Certain texts also make use of an instructional mode of description, presenting the artifact as a creation that comes together before the reader's eyes; many of these texts implicate the reader in this process through direct address and imperative commands. Ancient descriptions of machines make use of a rich store of rhetorical techniques in order not only to provide the reader with a mental picture of the artifact's physical form, but also to interpret the artifact and provide it with cultural context by unfolding the different types of knowledge it embodies (including scientific, mathematical, and craft knowledge). This process of interpretation is key to the classification of these passages as a kind of ekphrasis. Because of this interpretive aspect, ekphrasis should not be understood simply as description, but rather a powerful rhetorical mechanism illuminating the connection between objects and their culture of production or use. In order to encompass the full range of such connections, the project draws not only on technical literature such as construction manuals, but also on the representations of technological artifacts found in ancient historical, philosophical, and poetic works. This work shows that technical authors like Vitruvius and Hero of Alexandria, far from producing "naïve" descriptions of machines isolated from their culture, are in fact self-conscious participants in an ongoing discourse about the place of technical knowledge within the landscape of scientific, philosophical, and cultural values. This discourse reaches beyond the community of technical practitioners to influence literature in other genres; at the same time, the response of authors in other genres to contemporary technological developments influences the way technical authors present themselves and their work. In this way the project serves to explore the complex integration of ancient mechanical technology with the surrounding culture.

Keywords: Classics
Advisor: Netz Reviel primary advisor. Thesis advisor
Barchiesi Alessandro advisor. Thesis advisor
Gleason Maud W.
Peponi Anastasia-Erasmia advisor. Thesis advisor
Riskin Jessica advisor. Thesis advisor