VictorJuiz/thesis huggingface dataset:
Accelerator architectures for matrix applications [electronic resource]
Keywords: Electrical Engineering

Matrices are a well known data representation extensively used in a wide range of applications. Numerous applications of various domains use matrix operations to represent and perform their core algorithms. Thus, improving matrix operation performance is critical to a vast variety of fields as it not only allows existing applications to run faster, but also enables computations with larger matrices. Modern GPUs and CPUs with SIMD support have been very effective at accelerating matrix operations. However, these current architectures only work well on dense and fat matrices. Skinny dense matrices tend to underutilize SIMD resources when the width of a matrix is less than the number of SIMD lanes, and may limit the scalability since they have a smaller amount of computation to hide the communication overhead. Sparse matrices are also difficult to accelerate current architectures, because the memory accesses are irregular and the workload imbalance is severe. This thesis introduces two different specialized hardware, targeting narrow dense and sparse matrices. The first part of this thesis focuses on accelerating a Restricted Boltzmann Machine (RBM), a popular machine learning algorithm used in deep learning. The RBM accelerator was designed using a modular approach to achieve linear scalability across transistor technologies, as well as across chip boundaries. The accelerator was implemented on FPGAs to demonstrate the performance improvements over high-end CPUs and GPUs. Both fat and skinny matrices were shown to fully utilize the computation resources in the learning process, which allows the training algorithm to converges in less number of iterations. The second part of this thesis describes how sparse matrix applications can be accelerated with domain-specific hardware. We studied three sparse matrix applications that conventional hardware cannot easily accelerate. Based on our findings, we devised an accelerator architecture which targets certain sparse and dense matrix operations. The accelerator is capable of exploiting the fine-grained parallelism within sparse matrices despite the irregularity through buffering and work-stealing. In order to cover a wider range of applications, a small general-purpose core was added to the accelerator for non-critical execution flows. The sparse matrix accelerator was implemented on an FPGA board as an ASIC prototype to evaluate the performance using real-world data. Our accelerator shows performance comparable to GPUs on dense matrix operations, and excels over conventional hardware on sparse matrix operations.
Access, institutions and policy influence [electronic resource] : the changing political economy of trade protection in post-reform China
Keywords: Political Science.

This study introduces a dynamic theory of access and policy influence under authoritarianism, which argues that domestic interest groups facing foreign competition in authoritarian states are able to lobby for protection via both formal and informal channels of access to trade policymakers. In addition, these channels of access themselves change as the decision makers, the processes and the institutions of trade policymaking evolve over time, leading to the shifting abilities and strategies of certain domestic interest groups in providing incentives for relevant policymakers to set policies that are in favor of the interest groups. I test the theory by examining the domestic sources of trade protection across manufacturing industries in China, a single party authoritarian state, during its transition from a centrally-planned system to a market-oriented economy over the past six decades. Using three original, large-scale datasets and a variety of statistical models, I find that the percentage of state ownership and the geographical distribution of firms, two measures of an industry's access to trade policymakers, are significant predictors of industry-level protection in China. In addition, the domestic sources of protection change as institutional arrangements change: the 1998 administrative reform significantly reduced the influence of the state sector on China's negotiated tariffs in the WTO, while geographical distribution did not become important until after the Party delegated its trade policy decision-making power to the state bureaucracy upon joining the WTO. These findings are further supported by comparative case studies and interviews with government officials, firm managers, trade lawyers and scholars in China and the United States over a 12-month period. The empirical chapters demonstrated that the theory successfully explains the changing political economy of trade protection: the structure of protection in China's manufacturing sector, both across industries and over time, reflects not only the distribution of winners and losers from free trade and the cost of lobbying but also, more importantly, groups' differential and changing access to trade policymakers. These findings suggest that domestic groups in nondemocratic regimes have a greater impact on trade policies than is often recognized by conventional wisdom. In addition to enriching our understanding of interest group lobbying and trade policymaking in China, this study also contributes to existing work on the political economy of trade protection in China by (1) explicitly incorporating changes in the actors, institutions and processes of trade policymaking over time, (2) providing the micro-foundations of how interest groups lobby and influence trade policy outcomes in authoritarian states, and (3) accounting for both statutory (de jure) and administered (de facto) protection.
Accounting rules for debt covenants [electronic resource]
Keywords: Business.

This thesis examines the properties of accounting rules designed to maximize the efficiency of accounting-based debt covenants in a setting with incomplete contracts and asset substitution. Accounting takes the role of a state-contingent decision facilitator by inducing covenant violations, and hence a transfer of decision rights from the borrowing firm to the lender, whenever the lender has less detrimental decision incentives than the firm. This representation of accounting is distinctive in two respects. First, accounting does not have to enlarge the contracting parties' information sets but is nonetheless valuable because it provides verifiable information and hence improves contract efficiency. Second, accounting is an endogenously chosen information aggregation rule rather than an information signal with exogenous properties. The optimal accounting rule in this setting is a function of cash flows and fair value estimates and implements a debt contract with a unique optimal tradeoff between decision rights and interest rates. The optimal degree of conservatism of this accounting rule, measured as the tendency to yield low accounting measures and hence more frequent covenant violations, is higher for firms with high leverage, low profitability, and high liquidation values. Firm value is a convex function of financial leverage in this setting.
Acts of play [electronic resource] : games as experiential performance
Keywords: Theater and Performance Studies.

This dissertation addresses a major theoretical problem in performance studies: how to understand games (including play, sports, and so on) as a distinct mode of performance. It considers a wide variety of games across media and genres. Its central goal is to create critical frames that can help performance scholars analyze games alongside other types of performance (such as theater) without eliding their salient qualities, and conversely also help games scholars make use of performance as a way to address play. The first chapter explicates concepts of experience that describe unique and distinguishing qualities of play. It addresses ideas about experience from pragmatist philosophy, interaction design, and popular culture. It uses them to develop a framework for ludic experience that relates games to aesthetic performance, consumer electronics, narrative, efficacy, and affect. The second chapter describes performers other than players in games, which it describes as devices (such as sports equipment) and designs (such as rules). It uses perspectives from speech-act theory, theater criticism, design studies, and object-oriented ontology to help locate the performativity of nonhuman performers in play. It also considers how the device-design analytic merges and blurs in toys and videogames. The third and final chapter investigates how embodiment functions in games. Through further engagement with game studies, theater criticism, and gender theory, it develops constructs called the "game body" and "ludic subjectivity" that help describe how players create new bodies and identities through acts of play. By interpreting several distinct varieties of game practice -- from board games to play with avatars and puppets to tabletop roleplaying -- through the lens of the game body, it reveals a spectrum of modes of embodiment that become manifest in play. In doing so, it outlines a general critical method for examining how play transforms bodies and physical performance.
Actuation strategies for cycle-to-cycle control of homogeneous charge compression ignition combustion engines [electronic resource]
Keywords: Mechanical Engineering.

The mounting evidence of anthropogenic climate change necessitates a significant effort to improve the internal combustion (IC) engine and reduce its adverse environmental impacts resulting from its ubiquitous use powering ground transportation. Homogenous Charge Compression Ignition (HCCI) engines present a promising opportunity to reduce the environmental consequences of using IC engines by reusing exhaust from one engine cycle to initiate combustion on the following engine cycle. The presence of high retained exhaust ratios in HCCI engines results in dilute, low-temperature combustion that achieves greater efficiencies and lower CO2 and NOx emissions than conventional spark-ignited or diesel engines. However, three critical obstacles prevent them from being widely adopted: first, unlike conventional IC engines, HCCI engines lack a direct combustion trigger to determine when combustion occurs, and that lack of a direct trigger makes specifying combustion timing challenging. Second, the high quantities of retained exhaust create a strong physical link between engine cycles, resulting in undesirable dynamics that could potentially lead to engine misfire at certain operating conditions. Finally, the high quantities of retained exhaust also prevent the engine from inducting as much fuel and air as possible, limiting the load range of the engine. This dissertation addresses all three of those obstacles by investigating the abilities of different actuators to control combustion timing and improve the dynamics at certain HCCI operating conditions that could be used to expand the load range of HCCI engines. A simple, physical model that represents one engine cycle as a discrete-time, nonlinear system captures the oscillatory dynamics present at certain HCCI operating conditions on an experimental engine. The physical model provides physical intuition about the sources driving the oscillations and the control actions needed to reduce them. A linearized version of the model depicts the source of those oscillations on a root locus, and shows that a negative real axis pole in a discrete-time, linear dynamical system drives the oscillations. Three different actuators, exhaust valve closing timing, pilot fuel injection timing, and main fuel injection mass, each reduce the oscillations. For each actuator, a linearization of the physical model illustrates how each actuator can be used with simple linear control laws to improve the dynamics at HCCI operating conditions. Then, the actuators are compared to each other on three aspects: the difficulty of the control problem associated with using the particular actuator to reduce the oscillations, the difficulty of implementing the actuator in a production vehicle, and the effectiveness of each actuator at reducing the oscillations.
Adaptive and neutral evolutionary insights from statistical analyses of population genetic data [electronic resource]
Keywords: Biology.

Organismic evolution involves both selective and neutral forces, although their relative contributions are often unknown. This thesis proposes novel statistical methods for analyzing genetic data from a variety of organisms, including yeast, Mycobacterium tuberculosis, and humans. The chapters of this thesis provide complimentary perspectives on the relative roles of selection and neutrality, from the molecular to the population level, and present various statistical tools for genetic data analysis. Chapter 2 proposes a maximum-likelihood based method with which to classify and identify interactions, or epistasis, between pairs of genes. Chapter 3 details a study of genetic data from Mycobacterium tuberculosis isolated from human Aboriginal Canadian communities; our analyses suggest that the bacterium spread to these communities via the Canadian fur trade in the 18th and 19th centuries. Chapter 4 discusses the detection of signatures of natural selection in the genomes of 12 diverse African human populations, and proposes novel considerations for identifying biological functions under selection and for comparing signals of selection between populations. Finally, Chapter 5 details the inference of the genetic basis and evolutionary history of light skin pigmentation and short stature in the genetically diverse ≠Khomani Bushmen of the Kalahari Desert of South Africa, believed to be one of the world's most ancient human populations. These chapters emphasize that a more complete understanding of the evolutionary history of humans and other organisms requires not only the consideration of neutral and selective processes, but also both phenotypic and genetic information. The statistical methods and approaches presented in the following chapters have the potential to improve inferences of natural selection and demography from genetic data, as well as provide insight into the relative roles of both.
An adaptive filtering and control approach to problems in high frequency trading [electronic resource]
Keywords: Management Science and Engineering.

Today's security markets for most asset classes including equities, fixed income, currencies, and vanilla derivatives are increasingly dominated by algorithmic and high frequency traders. Market participants routinely place millions of quotes and trades per second with most individual trading decisions being made by smart computer algorithms and automated systems rather than by humans. As these trading systems have become more sophisticated over the last decade, very important but traditionally simple tasks of trade execution and market making now require traders to be smarter and more agile in order to be competitive and profitable. In view of these developments, we propose a novel approach to building trading strategies for both these kinds of traders. For the trade execution problem, in addition to the traditionally studied price impact models, we recognize the impact of trading on volatility, which is in turn related to liquidity. We model this new impact and solve for the optimal trading schedule, which now requires a dynamic response from the trader based on time-varying liquidity conditions. For the market making problem, we propose a flexible market model that not only captures the basic trade-offs faced by a market maker but is also robust to microstructure noise effects and anticipates the time-varying risk factors of volatility and correlation observed in real markets. We provide closed-form solutions describing the optimal quoting strategy in our market model, the first of its kind for making markets in multiple correlated securities. Furthermore, we call upon the most recent advances in sequential Monte Carlo methods (also known as particle filters, used filtering in general non-linear state-space models), employing a computationally efficient Markov Chain Monte Carlo scheme to perform joint filtering and parameter estimation, termed adaptive particle filters. We integrate these adaptive particle filters with our trade execution as well as market making models to filter for unobservable quantities of interest as well as to estimate unknown model parameters simultaneously and in real time. The use of this powerful method bridges some of the gap between theoretical models and applying them in practice, where unobserved quantities and unknown, time-varying parameters are the norm.
Advanced discretization methods for flow simulation using unstructured grids [electronic resource]
Keywords: Energy Resources Engineering.

Globally structured grids, including the so-called stratigraphic or CPG (Corner Point Geometry) approaches, are widely used in the reservoir simulation community. However, there has been strong and growing interest in developing methods, tools, and workflows that employ generally unstructured grids because they can represent the complexity of real geological formations more accurately and efficiently compared with structured grids. The great potential of unstructured grids comes with many challenges including (1) development of robust and efficient discretization schemes in the presence of heterogeneous (full-tensor) properties, (2) development of tools and inter-connects that make up the Characterization-Discretization-Simulation (CDS) workflow based on generally unstructured grids, and (3) detailed analysis of the effects of unstructured grids and advanced discretization schemes on the accuracy, robustness, and efficiency of general-purpose reservoir flow simulation. In this work, we describe a CDS workflow for unstructured grids. The tools and workflow allow for the construction and discretization of detailed unstructured Reservoir Characterization Models (RCMs) for the purpose of reservoir flow simulation. The main contribution of the work is the development and implementation of a discretization module for generally unstructured grids that is based on multi-point flux approximations (MPFA). This discretization software layer is called SupriPack, and it is implemented as a ``plug-in'' into the GoCad environment. SupriPack employs our newly developed flux-based framework for constructing MPFA discretization schemes. The flux-based approach is quite flexible. It accommodates three-dimensional unstructured grids with complex topology, as well as, heterogeneous, full-tensor, permeability fields. We show that the flux-based framework is a super-set of existing MPFA schemes, and it is compatible with methods that can adapt to the local anisotropy of the permeability. Several existing MPFA schemes, including ``O'' and compact, have been implemented and tested. We also demonstrate the full unstructured-grid CDS workflow using GPRS (Stanford's General-Purpose Research Simulator), which is an advanced research platform for compositional reservoir simulation using fully unstructured grids.
Advanced single molecule fluorescence analysis and force spectroscopy to understand myosin motors [electronic resource]
Keywords: Applied Physics.

Myosins are actin-based molecular motor proteins that are associated with numerous cellular functions both in muscle and non-muscle cells. In the past decades, single molecule biophysics has provided many useful in-vitro techniques that enable one to understand detailed molecular mechanisms of myosin-actin interaction. I will describe our results and continuing efforts in (i) single-molecule fluorescence localization analysis with TIRF microscopy, and (ii) single-molecule force spectroscopy with optical traps to understand myosin motors. Our theoretical point-spread function combined with maximum-likelihood-estimation precisely extracts both positions and orientations of fixed fluorescent molecules simultaneously. This approach is now mature as a structural tool, and I have applied it to two examples: myosin V labeled with a fixed dye walking on actin filaments, and dsDNA with two differently colored probes doubly attached to its backbone. We experimentally show that our method is not only precise but also accurate. Familial hypertrophic cardiomyopathies (HCM) are common genetic heart diseases that are often caused by single point mutations, especially in human beta cardiac myosin II. Using an optical trap assay, we found that the human beta cardiac myosin with the R453C HCM-causing mutation produces significantly elevated intrinsic force. We further developed a new method called harmonic force spectroscopy that can extract a force-velocity curve from a single cardiac myosin molecule. We found that a strong-to-weak transition of a cardiac myosin bound to an actin filament is modulated by an external load, which can be explained by simple Arrhenius transition theory.
Aesthetics of defamiliarization in Hedeigger, Duchamp, and Ponge [electronic resource]
Keywords: Comparative Literature.

Victor Shklovsky's of ostranenie, estrangment or defamiliarization, may be useful for understanding a broad range of artistic strategies in twentieth century art and aesthetics. Heidegger's theory of art, when read in light of his existential ontology in Being and Time, which is also a social theory, can be understood as providing a philosophical account of defamiliarization as having significance for both an ethics and an aesthetics. Duchamp's "readymades, " with their interrogation of the idea of art and the institutions and practices to which it belongs, derive their critical and experiential force from their effectiveness in rendering unfamiliar or strange a quotidian object that is industrially fabricated; in Duchamp's case, this raises a multiplicity of questions.
Algebraic modular forms on definite orthogonal groups [electronic resource]
Keywords: Mathematics.

The present thesis examines explicit computation with modular forms on definite orthogonal groups over the rational numbers. The space of functions on the genus of a definite quadratic form affords a natural representation of the Hecke algebra, which realizes the function space as a space of modular forms. The algorithm of the thesis computes the genus of a quadratic form as well as Hecke operators on the associated space of modular forms. A formula derived in the thesis yields Satake parameters from Hecke eigenvalues. Explicit examples of Satake parameters verify the correctness of the algorithm and the formula by their agreement with the predictions of the Arthur conjectures.