VictorJuiz/thesis huggingface dataset:
The song of love [electronic resource] : the afferent auditory pathway in Drosophila melanogaster

This thesis encompasses three projects at the intersection of genetics, behavior, and neurobiology in the fruitfly, Drosophila melanogaster. The major work presented is an investigation of the afferent auditory system in D. melanogaster. The afferent auditory system of D. melanogaster arises from the Johnston's Organ in the second antennal segment, from which mechanosensory neurons project to a protocerebral region known as the Antennomechanosensory and Motor Complex (AMMC). The antennal mechanosensory system in Drosophila is used in multiple contexts, including vestibular mechanosensation, wind sensitivity, and courtship hearing. During courtship, male flies present a stereotypic pulse song as well as a hum-like sine-song to female flies; these stimuli are species-specific and critical to female receptivity. Using a large enhancer-Gal4 collection, I identify 12 candidate cell types within the AMMC, divided into 7 types of projection neurons as well as 5 types of local AMMC interneurons. I tested each of these cell types for its effect on courtship hearing by testing the effect of neuronal silencing on a) female receptivity, and b) a male locomotor response (Song-Induced Locomotion). These tests reveal that the activity of one class of projection neuron (aPN1), and one class of local interneuron (aLN(al)) are critical to courtship hearing in both male and female flies. Other cell types appear to be dispensable for courtship hearing, and may play a role in non-courtship related mechanosensation. To help confirm that these phenotypes are not specific to neuronal silencing, I also hyperactivated each cell type using the temperature-sensitive dTrpA1 reagent; these results confirm that aPN1 and aLN(al) alone are necessary for courtship hearing. Overall this work identifies a set of parallel pathways from the AMMC leading to the ventrolateral protocerebrum (VLPR), but reveal that only one of these pathways is necessary for courtship hearing. The structure of this circuit is analogous to the multi-lineage projection identified in D. melanogaster olfaction, in which a parallel pathways share a common projection but carry independent information. In addition to this work, I also discuss an investigation of the role of abnormal-chemosensory jump 6 (acj6) on escape behaviors, as well as an investigation of the expression of doublesex (dsx) in the nervous system.

Keywords: Biology.
Advisor: Baker Bruce Stewart
Scott Matthew P. primary advisor. Thesis advisor
Luo Liqun
McConnell Susan K. advisor. Thesis advisor
Source region characteristics of magnetospheric ELF/VLF banded chorus emissions [electronic resource]

Geomagnetically trapped electrons with relativistic energies in the Earth's radiation belts may cause serious damage to spacecraft systems through their interactions with onboard electronics. Natural electromagnetic plasma waves, known as extremely low frequency/very low frequency (ELF/VLF) chorus, can increase the flux of relativistic electrons by accelerating electrons with energies in the keV range to energies in the MeV range. Chorus, observed in the magnetosphere outside the plasmapause, often appears in two distinct frequency bands separated by an emission gap, which occurs where the wave power exhibits a minimum. This configuration, known as banded chorus, consists of an upper band (UB) of chorus located above the emission gap and a lower band (LB) of chorus located below this gap. This dissertation explores the source region characteristics of magnetospheric banded chorus emissions using data from the Cluster spacecraft and the Polar spacecraft to advance our fundamental understanding of the properties of these waves. A new theory suggests that the emission gap between the upper and lower bands of chorus is due to ducting effects. To test this theory, plasmaspheric electron densities with the highest spatial resolution to date are determined for accurate identification of whistler-mode ducts. Wave normal angle distributions near the magnetic equator demonstrate that banded chorus can be generated within, and likely guided by, enhancement and depletion ducts and that lower band chorus emissions can be uniformly excited over an extended region. Further analysis of the wave normal angle distributions in the equatorial and off-equatorial regions shows lower band chorus tends to be quasi-field-aligned and upper band chorus tends to have oblique wave normal angles. Finally, the intensity of banded chorus is determined to have an exponential spatial dependence on distance away from the magnetic equator, providing a new boundary condition for chorus generation models.

Keywords: Electrical Engineering
Advisor: Inan Umran S. primary advisor. Thesis advisor
Bell Timothy F. advisor. Thesis advisor
Gill John T.
Spark [electronic resource] : modular, composable shaders for graphics hardware

Real-time computer graphics have become a ubiquitous part of modern life. Rich user interfaces and interactive games appear on screens ranging from mobile phones to stereo-3D TVs. Programmable graphics \emph{pipelines} have been central to delivering these compelling experiences. Shaders - programs that describe the shape, movement, and appearance of rendered objects - run in the stages of these pipelines, and are used to define the "look and feel" of a production. The demand for rich, immersive experiences motivates the use of increasingly complex shaders. In creating these complex real-time shaders, programmers should ideally be able to decompose code into independent, localized modules of their choosing. Current real-time shading languages, however, enforce a fixed decomposition into per-pipeline-stage procedures. Program concerns at other scales - including those that cross-cut multiple pipeline stages - cannot be expressed as reusable modules. We present a shading language, Spark, that improves support for separation of concerns into modules. A Spark shader class can encapsulate a program feature that maps to more than one pipeline stage, and can be extended and composed using object-oriented inheritance. We first discuss the design of this language: its origins, goals, and key design choices. We then describe our implementation of a compiler, standard library, and runtime system for Spark, targeting current programmable graphics hardware. Finally, we evaluate this implementation and demonstrate that it achieves our modularity goals without compromising performance: in our tests, shaders written in Spark achieve performance within 2\% of Microsoft's High Level Shading Language (HLSL).

Advisor: Hanrahan P. M. (Patrick Matthew) primary advisor. Thesis advisor
Aiken Alexander advisor. Thesis advisor
Akeley Kurt
The spectacle of the self [electronic resource] : the power of the press to make us be by telling us who we are

This project proposes an understanding of press power that focuses on the formation of the individual self and explores the role the press plays in crafting our sense of what it means to be a person. It argues that cultural approaches to the study of American journalism (which emphasize journalism's story-telling and common-sense-making roles over its role in information-transfer role) don't currently have an effective way of understanding press power. The model of power I propose to fill this gap is closely connected to the work of Michel Foucault and focuses on the intersection of visibility, truth, and the individual subject. The project's empirical investigation investigates seven news stories from major metropolitan newspapers in the U.S. and brings interviews with journalists and readers together with textual analysis of the stories themselves, emails written by readers directly to the journalist and published letters to the editor about the stories. The analysis reveals the importance of culpability questions as a mechanism for constructing the personhoods of the people in the paper and suggests that the these questions along with the righteous indignation they trigger function as tools that help make people available as recognizable subjects to the workings of power.

Keywords: Communication.
Advisor: Glasser Theodore Lewis
Bailenson Jeremy advisor. Thesis advisor
Inoue Miyako
Turner Fred advisor. Thesis advisor
A stable and conservative framework for detailed numerical simulation of primary atomization [electronic resource]

Energy conversion devices often rely on the combustion of high energy-density liquid fuel to meet weight and volume restrictions. The efficiency of the conversion and the emission of harmful pollutants depend directly on the mixing of the fuel and oxidizer, which itself results from a cascade of mechanisms initiated by the atomization of a coherent liquid stream. Despite existing investigations, the effects of nozzle design, surface tension, turbulence, and cavitation on atomizer performance are still poorly understood. The challenges found in experimental studies caused by the multi-scale and multi-physics aspects of such flows have motivated the development of numerical strategies to simulate the atomization process. In the direct numerical simulation approach considered in this work, the physics of the flow are all solved for directly. In the presence of complex topologies, the underlying equations are stiff, and, therefore, the development and improvement of numerical methods has been an area of active research. Among algorithms that have emerged, sharp interface methods including Volume-of-Fluid and Level Set have been shown to give reasonable performance. Applications of these methods to study primary atomization of turbulent jets have been documented, but the rare convergence studies available show strong grid dependence, suggesting the need for further developments. The present work focuses on two novel developments: an unsplit Volume-of-Fluid interface capturing algorithm designed to improve conservation on arbitrary grids, and a robust flow solver for incompressible Navier-Stokes equations in two-phase flows involving large density ratios. The resulting approach is shown to be stable and second order accurate. The framework is then assessed in a set of validation cases. In particular, the effect of mesh resolution is studied, and the ability of the method to accurately retain under-resolved structures is shown. Finally, computations of a large scale atomizer for varying operating conditions are presented. The excellent computational efficiency of the algorithm motivates the use of such a framework for simulating industrially relevant configurations.

Keywords: Mechanical Engineering
Advisor: Pitsch Heinz
Iaccarino Gianluca advisor. Thesis advisor
Lele Sanjiva K. (Sanjiva Keshava)
The state in training [electronic resource] : European Union accession and the making of human rights in Turkey

This dissertation traces the route and a key mechanism through which human rights continues to infuse into the state domain in Turkey. At its focus are the human rights training programs for state officials and government workers, held in line with Turkey's pending accession to the European Union (EU). In this ethnographic study of those training programs, I aim to scrutinize both the everyday governmental configurations of Turkey's accession to the EU and the effects of the particular framing of human rights engendered by the accession process. Built around these two main pillars, this study emerges in conversation with both the anthropological studies of transnational governance and the anthropology of human rights. Human rights training programs are part of a larger process to transform the national governmental field in line with good governance in Turkey. They are complementary to the legal amendments, and they aim to bring about attitudinal and behavioral transformation in the everyday agents and practitioners of governance. The contradiction between these agents' professional socialization, reflecting the nationalist imaginary that dominates the Turkish governmental realm, and the country's obligations arising from its EU candidacy designates training programs as highly contested sites. These sites, as such, display the complex everyday dynamics of transnational standardization processes. Integration of human rights into the governmental domain requires disassociating human rights from their established political connotations, and re-framing them instead as relevant to and compatible with practices of national governance. This is achieved by formulating human rights as a requirement of expertise and professionalism to which all state officials should subscribe in order to better perform their jobs. My work focuses on how this re-framing is administered, and how it is received by the state officials and government workers who participate in human rights training programs. By analyzing the wider implications, and both the intended and unintended consequences of human rights training programs, this dissertation also seeks to understand the constitutive terms and building blocks of the governmental sphere in Turkey, which an attention to the re-framing of human rights and its reception by the state officials helps illuminate.

Keywords: Anthropology
Advisor: Malkki Liisa H. (Liisa Helena) primary advisor. Thesis advisor
Beinin Joel
Ferguson James advisor. Thesis advisor
Inoue Miyako
Yanagisako Sylvia Junko
STM and STS studies of electronic states near macroscopic defects in topological insulators [electronic resource]

Bi2Te3 and Bi2Se3 have been argued to be 3D topological insulators, exhibiting a bulk gap and a single, non-degenerate Dirac fermion surface band topologically protected by time-reversal symmetry. In this dissertation we will discuss the physics of topological insulators. We will show that scanning tunneling spectroscopy studies on high-quality Bi2Te3 and Bi2Se3 crystals exhibit perfect correspondence to ARPES data, hence enabling identification of different regimes measured in the local density of states. Unique to Bi2Te3, we will discuss observation of oscillations of LDOS near a step. Within the main part of the surface band we found that the oscillations are strongly damped, supporting the hypothesis of topological protection. At higher energies, as the surface band becomes concave, oscillations appear which disperse with a particular wave-vector that results from an unconventional hexagonal warping term in the surface-state-band Hamiltonian. For both systems, a "bound state" was observed in the bulk gap region that runs parallel to the edge of the defect and is bound to it at some characteristic distance. An expression that fits the data, and provides insight into the general properties of the surface band near strong structural defects, can be obtained using the full three-dimensional Hamiltonian of the system. In the case of Bi2Se3 whose band structure doesn't exhibit warping we studied the effect of local defects (impurities) on the local density of states. Although no visible interference pattern was detected we observed resonances localized around the defects. Such resonances agree quantitatively with a theory due Biswas and Balatsky which treats impurities as local potential wells interacting with a 2D Dirac gas which models the surface state of a topological insulator.

Keywords: Physics
Advisor: Kapitulnik Aharon primary advisor. Thesis advisor
Fisher Ian R. (Ian Randal) advisor. Thesis advisor
Qi Xiaoliang advisor. Thesis advisor
Stochastic control via chance constrained optimization and its application to unmanned aerial vehicles [electronic resource]

Automation has had a strong presence in manufacturing for centuries, however its use in society has been very limited. The most ubiquitous robot in everyday life is the Roomba which has sold over 6 million, but the vacuuming task of this robot is simple in comparison with the difficult tasks performed in the manufacturing sector. Automation is successful in manufacturing because the task and environment can be well-defined to simplify the problem, whereas for automation to penetrate into society, it needs to safely operate in the presence of significantly greater uncertainty. Applications that could benefit from increased autonomy include: robot-assisted surgery, energy efficient control of buildings, autonomous control of vehicles, robotic assistance for elderly and disabled people, routing aircraft around weather, and home automation for tasks such as folding laundry, loading and emptying a dish washer, or tidying up a room. All of the above applications are examples of stochastic systems which contain three sources of uncertainty: process uncertainty, sensing uncertainty, and environment uncertainty. In order to safely operate in the intended domains, the system must account for all three types of uncertainty in generating a safe control strategy. This problem of generating control inputs for systems under uncertainty is commonly referred to as the stochastic control problem. One way of formulating this problem is as a chance constrained optimization problem that restricts the risk of violating the system's constraints to be below a user supplied threshold. This thesis develops several extensions over existing chance constrained programming solutions. The feedback controller is used to shape the uncertainty of the system to facilitate the satisfaction of the stochastic constraints, enabling previously infeasible solutions. Systems with component failures are also studied, and the computational complexity is drastically reduced over previous solution methods. The chance constrained framework is also extended to handle systems operating in uncertain environments. A novel hybrid approach is developed that uses a combination of sampling and analytic functions to represent the uncertainty. This approach results in a convex optimization program, guaranteeing the optimal solution and reducing the complexity over other methods. The formulation is further extended to incorporate future measurements of the uncertain environment to increase the performance of the system. The proposed stochastic control methods are solved in real-time to plan trajectories for a quadrotor unmanned aerial vehicle navigating in a three-dimensional cluttered, uncertain environment. The solution method enables the quadrotor to explore the environment to gather more information, allowing it to successfully complete its objective.

Keywords: Aeronautics and Astronautics
Advisor: Tomlin Claire J.
Boyd Stephen P. advisor. Thesis advisor
Rock Stephen M. advisor. Thesis advisor
Strategic and adaptive execution [electronic resource]

First, we consider a trader who aims to liquidate a large position in the presence of an arbitrageur who hopes to profit from the trader's activity. The arbitrageur is uncertain about the trader's position and learns from observed price fluctuations. This is a dynamic game with asymmetric information. We present an algorithm for computing perfect Bayesian equilibrium behavior and conduct numerical experiments. Our results demonstrate that the trader's strategy differs significantly from one that would be optimal in the absence of the arbitrageur. In particular, the trader must balance the conflicting desires of minimizing price impact and minimizing information that is signaled through trading. Accounting for information signaling and the presence of strategic adversaries can greatly reduce execution costs. Second, we consider a model in which a trader seeks to maximize expected risk-adjusted profit while trading a single security. In our second model, there is no arbitrageur, and each price change is a linear combination of observed factors, impact resulting from the trader's current and prior activity, and unpredictable random effects. The trader must learn coefficients of a price impact model while trading. We propose a new method for simultaneous execution and learning -- the confidence-triggered regularized adaptive certainty equivalent (CTRACE) policy -- and establish a polylogarithmic finite-time expected regret bound. This bound implies that CTRACE is efficient in the sense that the ([epsilon], [delta])-convergence time is bounded by a polynomial function of 1/[epsilon] and log(1/[delta]) with high probability. In addition, we demonstrate via Monte Carlo simulation that CTRACE outperforms the certainty equivalent policy and a recently proposed reinforcement learning algorithm that is designed to explore efficiently in linear-quadratic control problems.

Keywords: Electrical Engineering
Advisor: Van Roy Benjamin primary advisor. Thesis advisor
Giesecke Kay advisor. Thesis advisor
Johari Ramesh
Strategic interaction in oligopolistic markets [electronic resource]

This dissertation analyzes the strategic interaction of oligopolistic firms in environments with asymmetric information or switching costs. In the first part, I consider a model of single-unit procurement auction that allows for asymmetric bidders, statistically dependent private information, and interdependent costs. I show that its payoff relevant characteristics are nonparametrically identified from the distribution of bids conditional on observable cost shifters under some assumptions that are standard in the empirical auction literature. The result holds for a variety of sealed-bid auctions including first-price, second-price and all-pay. In the second part, I use the identification result to investigate the effect of competition on bidder behavior and procurement cost using highway auction data from Michigan. A bidder's distance to a project location is important in explaining participation and bid levels. However, there is no evidence of more aggressive bidding when competitors are located close to the project. This pattern is at odds with theoretical predictions based on first-price auctions with private costs but can be rationalized by a more general interdependent cost model. I use distance to the project as a cost shifter, and develop an estimation procedure that exploits variation in project locations. The findings point to significant common costs and to a high degree of correlation in private information. Model estimates are used to show that common costs and information correlation reduce the effect of competition on procurement costs by 28 percent relative to a benchmark that assumes independent private costs. Moreover, subsidies to weak bidders are estimated to cost 27 percent more than in the private costs benchmark. % In the third part (co-authored with Liran Einav), we develop a model for studying dynamic competition in environments in which frictions lead to partial lock-in of customers with a specific product. Due to the dynamic aspect associated with customer retention and acquisition, pricing incentives may be quite different compared to more traditional, static product markets. The stylized model we propose maintains certain symmetry properties that allow us to obtain existence and uniqueness of equilibrium. We then study the comparative statics of the model and derive a closed-form relationship between average equilibrium markups and the Herfindahl index. We illustrate how the model can be used by analyzing the effect of mergers in such a dynamic environment.

Keywords: Economics
Advisor: Wolak Frank A. primary advisor. Thesis advisor
Einav Liran advisor. Thesis advisor
Hong Han advisor. Thesis advisor