VictorJuiz/thesis huggingface dataset:
The large hadron collider and models of new physics [electronic resource]
Keywords: Applied Physics

The Large Hadron Collider (LHC) is pushing the boundaries of the Standard Model of particle physics. Quantum corrections push the mass of the Higgs to be very heavy; If the hints of the Higgs boson now seen at the LHC are in fact the Higgs, the lightness of the Higgs boson must be explained. Supersymmetry provides a natural explanation for the Higgs mass. This thesis discusses two aspects in Supersymmetric theories, how to build them and how to see them.
Large-eddy simulation of multi-material mixing and over-expanded nozzle flow [electronic resource]
Keywords: Aeronautics and Astronautics

Turbulent flows involving the interaction of shock waves and density variations are present in diverse areas of science and engineering. Inertial confinement fusion (ICF), for example, is a theoretical technology which could lead to clean, inexpensive energy for thousands of years to come. The implications of ICF are enormous as are the engineering challenges associated with it. One primary obstacle is modeling and avoiding the hydrodynamic instabilities which grow on the surface of the ICF capsule and which can prevent fusion from occurring. The commercialization of space exploration and privately owned satellites has led to an unprecedented number of orbital launches, which is expected to double each year for the foreseeable future. Modern rocket propulsion systems must become more reliable and efficient to sustain this growth. In the design of the supersonic rocket nozzle, a primary consideration is the avoidance of large flow separation caused by shock waves and the resulting lateral forces or side loads generated. These side loads decrease the lifetime of the nozzle and destabilize the rocket. Due to the complexity of this physical process and the extreme conditions in which it occurs, limited experimental data are available and still much is not understood. Being able to accurately model turbulence and its interaction with shock waves and multi-species mixing has broad impact on these and other problems. In this thesis, numerical simulation is used to model these turbulent interactions in simplified configurations of the two aforementioned applications, ICF and rocket nozzles. Large-eddy Simulation (LES) is used to explore the multi-material mixing processes of the Rayleigh-Taylor instability and the Kelvin-Helmholtz instability. Analysis of the data reveal interesting physics which were not previously documented and which have implications to astrophysical phenomena (type 1a supernovae) and advanced energy technology (ICF). LES is used to simulate an over-expanded planar nozzle which contains a shock wave turbulent boundary layer interaction. A new numerical method for simulating this type of flow is described and tested on a variety of configurations to demonstrate its improved effectiveness and accuracy over previous methods. The LES approach is then used to study the source of shock wave instability in the nozzle. A mechanism is identified and verified by additional simulations and a parametric study of the nozzle configuration. A simple, reduced order model is proposed which captures the shock wave dynamics using a fraction of the computational cost of LES.
Large-eddy simulation of shock/turbulence interactions in hypersonic vehicle isolator systems [electronic resource]
Keywords: Aeronautics and Astronautics

Despite more than fifty years of research into the advancement of supersonic combustion ramjets, or scramjets, the technical challenges associated with the development of a reliable hypersonic, air-breathing propulsion platform continue to frustrate engineers to this day. Although scramjets offer the potential of substantially increased cycle efficiency over other types of chemical-propulsion systems, extreme failure modes such as engine unstart, in which the isolator shock system is ejected through the inlet, may lead to in-flight loss of thrust. Since it is well understood that shock-induced separation may affect the onset of unstart, it follows that improved understanding of the physics of shock / turbulence interaction may lead to more accurate prediction of design margins in physical scramjet engines. It is therefore the aim of the present research to explore with high-fidelity large-eddy simulation (LES) two unit problems of shock / turbulence interaction often found in scramjet isolator systems: (1) that of an oblique shock impinging on a turbulent boundary layer and (2) that of a normal shock train in a constant-area duct.
Large-scale sequencing and functional characterization of antibody repertoires [electronic resource]
Keywords: Immunology.

Despite tremendous progress in understanding immune responses, the ability to characterize functional antibody responses remains limited. I developed a method that utilizes barcoding to enable high-throughput sequencing of paired heavy-chain and light-chain immunoglobulin sequences. This approach enables us to generate dendrograms of functional affinity-matured antibody responses, and express selected antibodies for functional characterization. This method was applied to a human who received an influenza vaccine, humans with Staphylocuccus aureus infection, a human with rhuematoid arthritis, an autoimmune disease, and a human who has lung adenocarcinoma, and is a long term non-progressor. These are examples in vaccination, infection, autoimmune disease and cancer, respectively. In each case, we show that we were able to obtain paired heavy and light chain sequences. We expressed selected antibodies for functional characterization and showed that we were able to obtain functional antibodies that bound to target antigens in each of the above indications. Furthermore, we also showed that large clonal families dominate in influenza vaccination, and that larger antibody clonal families have higher binding affinities. Taken together, the approach provides a method to directly characterize functional antibody responses that could advance our understanding of protective and pathogenic immune responses in health and disease.
Laser induced fluorescence characterization of cusped field plasma thrusters [electronic resource]
Keywords: Mechanical Engineering

Cusped field plasma thrusters are a recent development in electrostatic propulsion, aimed at improving operation in the low power regime. Several diagnostic techniques have been employed to characterize these discharges. The present study focuses on the use of laser induced fluorescence to map ion velocities throughout the plumes of several cusped field thruster variants. Laser induced fluorescence provides the opportunity to probe small plasma sources with high spatial resolution, and is particularly useful for studying plasma propulsion devices where hot, energetic and highly non-uniform environments can adversely affect intrusive probes. The first half of this thesis focuses on time-averaged laser induced fluorescence velocimetry for three cusped-field thrusters. While a time-averaged velocity diagnostic is adequate in determining overall performance, it cannot resolve the dynamics seen in oscillatory modes of thruster operation. The second half of this research focuses on the development of an advanced CW laser induced fluorescence diagnostic technique, capable of correlating high frequency current fluctuations to the resulting fluorescence excitation lineshapes. This method is validated using simulations and a 60 Hz xenon spectral lamp. It is then applied to an oscillatory mode of the diverging cusped field thruster. Results show that the positions of the ionization and peak acceleration regions in the thruster vary over the course of a discharge current oscillation, causing the ion velocities to fluctuate in time. This new method of time-synchronized CW laser-induced fluorescence will be invaluable for better understanding the dynamics of thruster operation as well as other quasi-periodic oscillatory discharges, in fields from combustion to materials processing, among others.
A lasso for hierarchical interactions [electronic resource]
Keywords: Statistics

Building predictive interaction models is an important yet challenging problem, especially when the number of variables is large. Statisticians commonly demand that an interaction only be included in a model if both variables are marginally important. We study the problem of identifying hierarchical two-way interaction models from the viewpoint of the Lasso (i.e., L1-penalized regression). We show that we can produce sparse interaction models that honor the hierarchy restriction by adding a set of convex constraints to the Lasso problem. In contrast to stepwise procedures that are most commonly used for building interaction models, our formulation is convex, and so its solution is completely characterized by a set of optimality conditions. This makes it easier to study as a statistical estimator and gives a precise characterization of the effect of the hierarchy restriction. We prove under mild conditions that hierarchy holds with probability one and derive an unbiased estimate for the degrees of freedom of our estimator. A simple bound on this estimate gives a sense of the amount of fitting "saved" by the hierarchy constraint. We distinguish between two types of sparsity: parameter sparsity -- the number of nonzero coefficients in the model -- and practical sparsity -- the number of raw variables one needs to measure to make predictions in the future. While most statistical procedures focus on the former, the restriction to sparse hierarchical interactions gets at the latter, which is the quantity more closely tied to important data collection concerns such as cost, time, and effort. A simulation study reveals the relative statistical merits of the hierarchy assumption in different settings. We demonstrate our method in both linear and logistic regression settings on an HIV-1 drug resistance dataset and a classification problem involving olive oil. Our method has potential applications in genomewide association studies and other situations in which interactions may be important. Finally, we describe an algorithm that forms the basis of the hiernet package that we have created in R.
Learning feature representations for music classification [electronic resource]
Keywords: Music

In the recent past music has become ubiquitous as digital data. The scale of music collections in some online music services surpasses ten million tracks. This significant growth and resulting changes in the music content industry pose challenges in terms of efficient and effective content search, retrieval and organization. The most common approach to these needs involves the use of text-based metadata or user data. However, limitations of these methods, such as popularity bias, have prompted research in content-based methods that use audio data directly. The content-based methods are generally composed of two processing modules--extracting features from audio and training a system using the features and ground truth. The audio features, the main interest of this thesis, are conventionally designed in a highly engineered manner based on acoustic knowledge, such as in mel-frequency cepstral coefficients (MFCCs) or chroma. As an alternative approach, there is increasing interest in learning features automatically from data without relying on domain knowledge or manual refinement. This feature representation approach has been studied primarily in the areas of computer vision or speech recognition. In this thesis, we investigate the learning-based feature representation with applications to content-based music information retrieval. Specifically, we suggest a data processing pipeline to effectively learn short-term acoustic dependencies from musical signals and build a song-level feature for music genre classification and music annotation/retrieval. While visualizing the learned acoustics patterns, we will attempt to interpret how they are associated with high-level musical semantics such as genre, emotion or song quality. Through a detailed analysis, we will show the effect of individual processing units in the pipeline and meta parameters of learning algorithms on performance. In addition to these tasks, we also examine the feature learning approach for classification-based piano transcriptions. Throughout experiments on popularly used datasets, we will show that the learned feature representations achieve results comparable to state-of-the-art algorithms or outperform them.
Learning in social and economic networks [electronic resource]
Keywords: Electrical Engineering

Social and economic networks are becoming increasingly important, both on the internet and otherwise. Agents in these networks possess limited information, and interact chiefly with their local neighborhood. Yet these networks have proven remarkably effective at the aggregation of 'information' at massive scales. It is of great scientific and commercial interest to build realistic models for phenomena in networks of agents. This thesis focuses on understanding the dynamics of interaction between agents on social and economic networks, and developing general theoretical tools in this context. Exchange networks model the behavior of a set of players who need to reach pairwise agreements for mutual benefit, as in the labor market, the housing market and the 'market' for social relationships. A crucial but little understood aspect of exchange networks is the dynamics of bargaining between players. We present a natural model of the bargaining dynamics in general networks, and show rapid convergence to certain socially optimal outcomes. We also describe internet-based experiments on bargaining in networks, which are the largest such experiments to date. In many contexts, agents 'learn' behavior from interaction with friends/neighbors on a network. We call this phenomenon 'social learning'. We focus on models of repeated interaction, with agents 'voting' in a series of rounds on some issue of interest. Votes in the initial round are based on 'private signals', whereas votes in future rounds incorporate knowledge of previous votes cast by friends. Thus, information is aggregated by the network via iterative updates. We consider two different models of iterative learning. A very simple model is 'majority dynamics' where agents choose their vote based on the majority of neighbors' votes in the previous round. We analyze this model on regular trees. At the other extreme is iterative Bayesian learning: a fully rational model introduced by Gale and Kariv (2003). We introduce new algorithms for this model, challenging a widespread belief that it is computationally intractable. We develop a novel technique -- the 'dynamic cavity method', which serves as a key analytical and algorithmic tool, and is generally applicable to social learning dynamics on tree networks. Finally, we prove fundamental limits on the rate of information aggregation in tree networks via social learning, when votes are discrete.
The legal culture and migration [electronic resource] : structure, antecedents and consequences
Keywords: Law.

The concept of legal culture has been receiving a growing attention from scholars; more recently, it has been the subject of numerous empirical investigations. However, this research is often over-generalizing, because it overemphasizes the similarity of the opinions held by different segments of population. Furthermore, the relationship of migration and the change—or persistence—of the attitudes and perceptions that constitute legal culture has not received particular attention in the scholarly literature. Drawing on 102 in-depth interviews with representatives of three segments of the Israeli population—immigrants of the early 90's from the former Soviet Union, secular Israeli Jews and members of the Israeli Diaspora in Silicon Valley, CA—this research investigates various aspects of legal culture. First, exploring four parameters of the legal culture—attitudes towards the rule of law, the subjective significance of individual liberty, perceptions of the neutrality of law, and dispute resolution preferences, including readiness to pursue rights and attitudes towards the courts—this study provides a comprehensive account of the legal cultures of these three groups. The second important finding of this research is the persistence of the attitudes and perceptions that constitute legal culture over time. It appears that although two decades elapsed since the respondents of the first group emigrated from the former Soviet Union to Israel, they still express notions and demonstrate attitudes that bring to mind the Iron Fist of the Soviet Rule. Additionally, it appears that the attitudes characteristic of the pre-immigration outlooks affects—to a certain extent—the socialization of the new generation growing up and being educated in Israel. Finally, this research calls into focus the significant disparities of the attitudes between various groups of population, leading to the conclusion that these differences warrant special consideration on the part of the policy-makers, whose ability to effectively secure desired behavior by means of regulation is linked to the attitudes of the population.
The life of me upon my death among us [electronic resource] : Seneca's repetitive suicides, his continuous dictation and the scribes who based the genre of historiography on his death
Keywords: Drama

Seneca's tragic works are performative texts that bring to attention particular periods in theatre history that relied heavily on Seneca's writing. Works of Elizabethan writers, or plays from the early French baroque incorporated Seneca through translation, copying and emulation. This practice relates Seneca's own use of the ancient Greek and Roman texts as a pastiche method of composing his own tragedies. The historiography written around Seneca's death moment performs what Seneca's own letters and essays prescribe, in that writing the self, the passions and pleasures of acting on behalf of the self and the prolonged but determined path to death, all contribute to creating the Senecan self, on its daily quest to contain experience and past time within a complete daily composition. Seneca's relationship to space -- that of his private home dedicated to creation, that of the Domus Aurea dedicated to politics, and that internal mind space -- is at the center of the relationship between his tragedies and the geopolitics of the Roman Empire in the Silver Age. Written for the stage while mimicking the stage of politics, the tragedies are innovative compositions in replicating and improving their Greek ideal predecessors.
Living The Dream: How Enrichment Program Minority Students Negotiate Ethnicity and Conceptualize Class at Elite Educational Institutions
Keywords: enrichment program
ethnicity
race
class
reproduction theory
cultural mainstreamer
cultural straddler
noncompliant believer
Thesis

This study examines how minority students from an enrichment program based in New York City negotiate race and conceptualize social class at elite private schools. Eleven students who have graduated from the program were extensively interviewed about their experiences in high school and college. The major finding of this study is that students who appear to be assimilated into white mainstream middle class culture tended to emphasize the “social construction” and cultural constituents of class more than students who straddled both white and minority cultures, as they emphasized the income element in class. Their interviews reveal that the “mainstreamers” tended to describe the development of their individuality at school, whereas the straddlers were more prone to focus on social structures of inequality, especially in relation to interpersonal racial conflicts at their elite school. This trend was not apparent in the two mainstreamers who expressed socialist or socialist-leaning viewpoints, as they focused on social structures of inequality, much like the straddlers. The single student in this study who chooses not to embrace or perform white mainstream culture in virtually any setting expressed a strongly developed race consciousness while reflecting little or no class consciousness.
The local poet in the romantic tradition [electronic resource]
Keywords: Comparative Literature

Many poems evoke a sense of place; few poems, however, forge a lasting connection between a poet and a particular locale. In "The Local Poet in the Romantic Tradition, " I chart the evolution of this latter type of poetry and document its influence on readerly tastes in Britain over the last two hundred and fifty years. Parting ways with previous studies, I take the view that local poetry is defined less by the invocation of specifically named locations, or even by a proclivity for amassing topographical detail, than by the cultivation of a special kind of poetic ethos. Drawing on the works of William Wordsworth as well as a range of pre- and post-Romantic poets, I examine different instantiations of this ethos and outline the contours of the tradition of local poetry in Britain from its origins in the eighteenth century to its rise to prominence in the Victorian era.