VictorJuiz/thesis huggingface dataset:
Quasi-Monte Carlo methods in non-cubical spaces [electronic resource]
Keywords: Statistics.

Monte Carlo integration is a widely used technique for approximating high dimensional integrals. However, due to the inherent randomness of this method, the convergence is typically slow. Quasi-Monte Carlo (QMC) on the other hand gives a much better rate of convergence by using low-discrepancy sequences. These point sets are much more uniformly distributed than random samples. Most QMC research focuses on sampling from the unit cube. However, many problems in real-world applications are defined over much more general spaces, such as triangle, spheres, spherical triangles and discs. This dissertation deals with solving such problems of numerical integration defined over non-cubical domains. We introduce two QMC constructions in the triangle with a vanishing discrepancy. The first is a version of the van der Corput sequence customized to the unit triangle. The second construction rotates an integer lattice through an angle whose tangent is a quadratic irrational number. We then generalize the van der Corput construction to study the problem of numerical integration over the Cartesian products of s spaces of dimension d via scrambled geometric nets. We also show the asymptotic normality of the scrambled geometric net estimator. We further discuss some of the issues of why transformations of the unit cube to the domain of interest fails to give good results. Since products of simplices is throughout of special interest to us, we end the dissertation with few results of QMC tractability on that domain.
The queen of heaven and a goddess for all the people [electronic resource] : kingship, religion, and cultural evolution between Greece and the Near East, 3000-500 BCE
Keywords: Classics.

This dissertation traces the evolution of the ideologies of divine kingship within the cultural groups of western Asia and the eastern Mediterranean across the Bronze and Iron Ages through textual and material sources concerning the worship of the Queen of Heaven. Using a range of case studies from the Bronze and Iron Ages to understand the shifting meanings of this deity and her relation to earthly kingship, I argue that the Iron Age Greeks, even as they experimented with novel egalitarian forms of rule, engaged with and transformed discourses of divine kingship through mythical and ritual practices that critiqued and reoriented human beings' relationships with the gods. The major aim of this study is to develop a comprehensive historical perspective on Greece and its cultural, social, and political relations with cultural groups to the east through the shared ritual language surrounding divine kingship. To this end, along with my case studies, I consider theories of cultural evolution of religion, and in particular religion's role in the cultural and cognitive shifts that heralded the axial age, to understand the trajectories and meanings of these shifting relationships, between Greece and the Near East, king and society, and humans and their gods.
Questioning terrorism [electronic resource] : Islam, religious violence, & secular law in America
Keywords: Anthropology.

Based on 18 months of fieldwork in New York City, this dissertation explores the ways in which secular law in the United States intervenes in defining, regulating, and containing Islam through terrorism cases. Through ethnographic data culled from seven domestic terrorism trials, fieldwork amongst three Muslim civil liberties organizations, and ethnographic interviews with the families and friends of terrorism defendants, this dissertation argues that what is at stake in terrorism prosecutions is not merely the elimination of violence, but also forms of Islamic thought and practice deemed to exceed the secular state's definition of legal or "permissible" religion. While social science research has primarily focused on the experience of everyday Muslims following 9/11, this dissertation focuses on what the social and legal life of terrorism cases - both inside and outside of courtrooms - reveals about the contradictions, contingencies and anxieties of the secular security state, and the place of Muslims in America today.
Questions, answers, participants and interactions in open asynchronous online forums for learning English [electronic resource]
Keywords: Education.

On community question-answering (QA) sites, anyone on the open Internet can post a question, give a response, or browse a discussion. The availability of interested individuals, including content experts, implies that personalized tutoring can be crowd-sourced at no financial cost to users. Importantly, these forums maintain banks of knowledge often ranked by Internet search engines, thereby exerting influence over a wide audience. In addition, in the context of second language learning, the asynchronous format of the forums allows learners to ask questions in a low-stress environment while they attend to both language form and meaning. The current study focused on online forums that aimed at providing answers to questions from learners of English as a second or foreign language. To examine the characteristics of the questions, the participant networks, the quality of the answers, and the characteristics of the verbal interactions in the knowledge transfer and construction processes, this project conducted case studies of two QA sites with distinct differences in history and design, especially in terms of their levels of gamification and their discussion structures, and compared a sample of similar threads on the two sites. The coding schemes for answer quality and verbal interactions were developed based on the literature on information quality, and that on online collaborative learning, respectively. The most prominent strength of the sites was found to be their timeliness in delivering responses. In most cases, original questioners received answers within 24 hours. Even though the majority of the top answers offered usable conclusions and fully accurate information, a notable minority could be misleading in the sense that they seemed to allow questioners to arrive at conclusions but provided only partially accurate information. Consequently, potential users are recommended to view the information from QA sites only as one of multiple sources of information, and to further extract value by taking note of the citations the answers include. The two sites were markedly different in terms of answerer composition, likely as a result of their distinct historical roots. The study also found differences in answer characteristics, particularly in terms of accuracy and the use of references. Some interactive moves of the participants, especially the frequencies of responses, disagreement and answer revisions, appeared to be associated with the composition of the communities, gamified incentives, discussion structures, or some combination of the above. Further research is needed to identify any causal relations involved in order to better inform the design of online communities.
Rabbinic textuality and the rise of Jewish literature in imperial Russia, 1867-1904 [electronic resource]
Keywords: Comparative Literature.

In "Rabbinic Textuality and the Rise of Jewish Literature in Imperial Russia, " I propose a new account of the development of Jewish literature in the Russian Empire, by analyzing the works and personal histories of seven central Jewish writers: A.U. Kovner (1842-1905), Y.E. Kovner (1840-1891), M.L. Lilienblum (1843-1910), M.Y. Berdichevsky (1865-1921), H.N. Bialik (1873-1934), S. An-sky (1863-1920) and Y.L. Peretz (1852-1915). The dissertation tells the story of Talmud-learners, trained in the rabbinic practice of textual study for its own sake (Torah lishma), who struggled to transform themselves into secular writers in a world where the production of literature was required to serve a practical purpose. Using a comparative lens, I illuminate the formation of Jewish literature alongside a parallel and equally-troubled process among the Jewish writers' contemporaries, the 19th-century Russian Orthodox seminarians who became secular writers, situating the formation of secular literatures in the Russian imperial context.
Race, place, and political action [electronic resource] : how social norms and racial segregation shape participatory patterns in America
Keywords: Political Science.

The question of why some but not all citizens become politically active is one of the oldest in American politics, yet remains insufficiently answered. In particular, theories to date are unable to explain differences in political participation across racial and ethnic groups, a phenomenon that is increasingly important as America continues to diversify. In response, I present the Segregated Influence Model, a novel theory of political participation that considers how race and community alter the social context of political action and in turn, the choice to engage. Through original survey experiments, observational data, and qualitative research, I demonstrate that racial segregation leads to variation in social norms regarding the value and meaning of political action in America. This variance alters the rate at which individuals choose to become active, producing differences in aggregate participatory patterns. By considering the impact of social context on political behavior, I provide in this book a nuanced account of normative influence and am able to explain the macro- level patterns of political participation central to understanding politics in the modern United States.
Rags to riches? [electronic resource] : social origin-based stratification among early career college graduates
Keywords: Sociology.

The purpose of this dissertation is to investigate the consequences of low social origins among young college-educated adults. I argue that the relevance of social origins among college graduates grew over the past thirty years and, among recent cohorts, low social origins negatively influence early career outcomes. In the first empirical chapter of my dissertation I examine what the relationship between social origins and early career economic outcomes looks like and how it has changed over time. Next I examine specific differences in early career outcomes within one cohort of college graduates and the extent to which they can be explained by demographic or other characteristics. The third empirical chapter explores differences across institutions in the relationship between origins and economic outcomes. I then suggest that these relationships cannot be explained by academic trajectories or institutional differences and suggest several paths forward for research. Collectively, these analyses illustrate that college has become less of an equalizer among adults early in their career.
Rapid adaptation in complex demographic scenarios [electronic resource]
Keywords: Biology.

This thesis explores the population genetics of rapid adaptation in demographically complex scenarios, extending analyses that were previously developed modeling populations of constant size. The first chapter extends the understanding of soft selective sweeps—adaptive events where more than one adaptive allele spreads through a population while selection is acting on a common trait—in the Wright-Fisher model of evolution to populations that fluctuate arbitrarily but predictably through time. The second chapter investigates soft selective sweeps in the context of evolutionary rescue, an phenomenon where a population destined for extinction is 'rescued' by the appearance and spread of an adaptive mutation. The third chapter reviews a specific case of rapid adaptation, the evolution of drug resistance, and the population genetic insights that have been gained and applied to the study of drug resistance.
Rapid melt growth technique for III-V integration on Si substrates [electronic resource]
Keywords: Materials Science and Engineering.

The aggressive scaling of transistors driven by Moore's law is expected to continue in the future. Technological innovations at the system and process levels may facilitate the scaling to some extent. However, the physical limitation of Si materials is likely to put an end to Moore's law scaling. Novel materials with superior carrier transport properties are actively being studied to extend Moore's law. Among all the novel materials, III-V materials are one of the most promising candidates to replace Si due to their outstanding carrier transport properties. The heterogeneous integration of III-V materials on Si substrates not only enables the future scaling of electronic devices, but also offers a few other advantages, for instance, vertical integration of different functionalities on the same silicon-based CMOS platform, freedom of materials selection and possibilities of bandgap engineering. However, there are technological challenges to grow compound materials on silicon substrates due to the large lattice mismatch. In this thesis, a promising technique called Rapid Melt Growth is studied for III-V integration on Si substrates. A background of III-V integration on Si substrates is introduced first. Then a detailed study of the growth mechanism during RMG is performed. Three major nucleation scenarios are discussed: 3D homogeneous nucleation, 3D heterogeneous nucleation and 2D heterogeneous nucleation. The study is used to explain under what conditions the crystal growth originates from the seed region. Third, A thermal simulation is conducted to understand the thermal distribution inside the stripe during crystallization. The simulation results are then used to explain twinning crystals growth. Fourth, an analytical model is derived to predict the elemental segregation during the RMG process. This model fits the short stripe where complete mixing conditions apply. Fifth, two diffusion processes in RMG are investigated: solid state diffusion and liquid state diffusion. The effect of both diffusion processes on the crystal quality is discussed. Finally, a solution is proposed to prevent the liquid state diffusion of the Si seed region into the III-V stripe. The process optimization of this solution is described in detail. The best EBSD results of InAs RMG on Si substrates using this solution are presented. Both electrical and optical measurements are done on the as-grown InAs RMG materials to test the crystal quality.
Rates of convergence of Markov chains to stationarity [electronic resource] : strong stationary times, coupling, Gelfand pairs and comparison theory
Keywords: Mathematics.

The main purpose of this thesis is to find the mixing time for various random walks that the math community has been interested in. The methods used in this thesis are strong stationary times, introduced by Aldous and Diaconis, a coupling argument that was inspired by work of Aldous, bounding the eigenvalues of a walk via comparison theory and path arguments introduced by Diaconis and Saloff-Coste and via Gelfand pair theory developped by Diaconis and Shahshahani, but also finding the eigenvalues of random walks using Fourier Transform arguments as introduced by Diaconis and Shahshahani. There are many norms that can use to study the mixing time of a random walk on a finite group. Coupling is used to bound the ^1$ norm, strong stationary times are used to bound the separation distance, while the eigenvalues of a reversible Markov chain are used to bound the ^2$ norm. This thesis focuses on specific examples of Markov chains on finite spaces, some of which have been studied before but through a different norm.
Rationalizing Torture: How Giving the Public Information about Torture's Effectiveness and Necessity Influences Public Support for Torture
Keywords: Center for International Security and Cooperation
torture
public opinion
effectiveness
necessity
waterboarding
Thesis

Recent debates on the Senate Report on Torture and statements made by Donald Drumpf that he would bring back “a hell of a lot worse than waterboarding” emphasize that the case on torture has not been closed. Given the important role that public opinion plays in modern policy choices, this research aims to address the following question: in the context of a highly threatening scenario, how does giving the public information about torture’s effectiveness and torture’s necessity influence support for torture? Findings from this research indicate that a considerable proportion of the public would disregard established legal and moral norms against torture—particularly when told that torture produced useful information, was necessary, or has a high probability of causing a terrorist suspect to produce critical intelligence.

However, findings also confirm that the public heavily rationalizes their views on torture: torture supporters define waterboarding as torture significantly less often than torture opponents (eg. 64% v. 98%) and hold less favorable feelings toward Muslims. Some evidence is suggestive of retributive motivations at play. Meanwhile, when presented with information about effectiveness and necessity, both Republicans and Democrats respond in utilitarian manner to some degree, but still express significant polarization on torture. Furthermore, they explicitly rationalize their positions differently: Democrats opposed to torture appeal primarily to deontological moral opposition while Republicans in favor of torture largely defend their support by appealing to necessity. Ultimately, this study concludes that information matters to Americans, but how they receive it may depend on their preferred side of the aisle.
Reaching for “Moonshots”: Exploring the Persistence of Community College Transfer Students Who Applied to Highly Selective Universities
Keywords: community colleges
highly selective universities
higher education
validation
persistence
social support
first-generation
low-income
transfer students
Thesis

The American community college is currently a place where underserved populations, particularly substantial numbers of low-income and first-generation students, get a "second chance" at higher education and professional training. Many community college students opt to transfer to four-year institutions due to the rising necessity of an undergraduate education, and established pipelines of support channel students into affiliated public and/or state schools. Some students, however, decide to stray from these norms and apply to highly selective universities that have historically accepted low numbers of transfer students. This study interviewed twelve students who successfully transferred into a highly selective, research-intensive university. It explores the social relationships and interactions that transfer students perceive as contributing to their ability to apply and transfer to a highly selective university. The findings of this study revealed that the students maintained a strong drive to apply to these universities and sought out “validating agents” who willingly encouraged, affirmed, and supported their decisions. Moreover, the findings suggest that transfer students do not always attain goal support and instrumental support toward their desired goals, leading to a series of recommendations to help improve educational opportunities within this system.
A real-time framework for kinodynamic planning with application to quadrotor obstacle avoidance [electronic resource]
Keywords: Aeronautics and Astronautics.

This thesis presents a full-stack, real-time planning framework for kinodynamic robots that is enabled by a novel application of machine learning for reachability analysis. As products of this work, three contributions are discussed in detail in this thesis. The first contribution is the novel application of machine learning for rapid approximation of reachable sets for dynamical systems. The second contribution is the synthesis of machine learning, sampling-based motion planning, and optimal control into a cohesive planning framework that is built on an offline-online computation paradigm. The final contribution is the application of this planning framework on a quadrotor system to produce, arguably, one of the first demonstrations of fully-online kinodynamic motion planning. During physical experiments, the framework is shown to execute planning cycles at a rate 3 Hz to 5 Hz, a significant improvement over existing techniques. For the quadrotor, a simplified dynamics model is used during the planning phase to accelerate online computation. A trajectory smoothing phase, which leverages the differentially flat nature of quadrotor dynamics, is then implemented to guarantee a dynamically feasible trajectory. An event-based replanning structure is implemented to handle the case of dynamic, even adversarial, obstacles. A locally reactive control layer, inspired by potential fields methods, is added to the framework to help minimizes replanning events and produce graceful avoidance maneuvers in the presence of high speed obstacles.
Reciprocal play fuels the social construction of early altruism [electronic resource]
Keywords: Psychology.

Altruism, the act of promoting others' welfare, is a key aspect of human life. Is altruism a phenomenon that can be counted upon to flourish in the absence of social experience? I conducted this dissertation research in the context of research suggesting that altruism is a "natural" phenomenon that arises independent of any kind of social experience. By contrast, I propose that much of young children's altruism can be fostered by a subtle aspect of social experience. Specifically, I argue that reciprocal interactions -- exemplified in early childhood by reciprocal play -- are a plausible mechanism for the rise of early altruism. As such, Section 1 uses the methodology of research on "natural altruism" to show that reciprocal play is key for the expression of altruism in infants and toddlers (Study 1 and 2), as well as in preschoolers (Study 3). Section 2 suggests why this altruism presents itself: Reciprocal play fuels expectations of benevolence (Study 4), and when these expectations are experimentally manipulated, altruism flourishes (Study 5). Section 3 moves from examining the possibility that reciprocal play is a trigger of altruism to examining whether reciprocal play is a plausible mechanism for the socialization of altruism. Indeed, Studies 6-9 suggest that when parents practice reciprocal play, altruism flourishes across a variety of contexts. All in all, I argue that reciprocal play is a key driver for the social construction of early altruism.