VictorJuiz/thesis huggingface dataset:
Politics of Impasse: Specters of Socialism and the Struggles for the Future in Postwar Bosnia-Herzegovina

This dissertation is an ethnography of contemporary Bosnia-Herzegovina that examines the central conundrum of the country's postwar life: the seeming contradiction between the high levels of political dissatisfaction among its citizens and the absence, perhaps even the impossibility, of a mass mobilization that could usher in meaningful change. Through an anthropological investigation of everyday politics, community dynamics and grassroots activism, this thesis look at how the terms of the Dayton Peace Agreement, which stopped the war but deferred crucial political questions, created a political impasse while turning the future into an urgent political problem./nThis impasse, marked by contradictory hopes of a great violent transformation and what has come to be known as the "problem of political apathy," produces unique configurations of the political field to which this dissertation is dedicated. In order to understand how a flowering of unconventional political interventions becomes possible alongside a systematic disengagement from political affairs, one must attend not only to the structural conditions that have produced this sense of suspension, but also consider the effect of thick histories on the political imagination and contemporary dispositions and sensibilities. The bloody Bosnian war, which took place between 1992-1995 within a decade-long dismantling of Yugoslavia, has undoubtedly left a dramatic impact on collective consciousness. But so have too the often-sidelined decades of socialism, which helped shape norms and attitudes about the place of politics in public life./nThis dissertation gives attention to the intersections of the postwar projects of social reengineering, and the forms of political action and thinking inherited from socialism. It argues that political subjectivity cannot be understood except in specific historic and socio-cultural coordinates, and demonstrates that certain kinds of orientations that are often seen as "apathetic", "illiberal" and "pathological" are in fact ethical, active and responsible. The skepticism with which many Bosnians approach political participation today is the product of acute awareness of limits of transformative capacity of all political action./nPolitics of Impasse is based on over two years of ethnographic fieldwork in Sarajevo, Bosnia's capital, as well as the town of Jajce, the famed birthplace of socialist Yugoslavia, and finally, the regional center of Banja Luka.

Advisor: Yurchak, Alexei
The Etiology of Presbyopia, Contributing Factors, and Future Correction Methods

Presbyopia has been a complicated problem for clinicians and researchers for centuries. Defining what constitutes presbyopia and what are its primary causes has long been a struggle for the vision and scientific community. Although presbyopia is a normal aging process of the eye, the continuous and gradual loss of accommodation is often dreaded and feared. If presbyopia were to be considered a disease, its global burden would be enormous as it affects more than a billion people worldwide./nIn this dissertation, I explore factors associated with presbyopia and develop a model for explaining the onset of presbyopia. In this model, the onset of presbyopia is associated primarily with three factors; depth of focus, focusing ability (accommodation), and habitual reading (or task) distance. If any of these three factors could be altered sufficiently, the onset of presbyopia could be delayed or prevented./nBased on this model, I then examine possible optical methods that would be effective in correcting for presbyopia by expanding depth of focus. Two methods that have been show to be effective at expanding depth of focus include utilizing a small pupil aperture or generating higher order aberrations, particularly spherical aberration. I compare these two optical methods through the use of simulated designs, monitor testing, and visual performance metrics and then apply them in subjects through an adaptive optics system that corrects aberrations through a wavefront aberrometer and deformable mirror. I then summarize my findings and speculate about the future of presbyopia correction.

Advisor: Roorda, Austin
Porous Core-Shell Nanostructures for Catalytic Applications

Porous core-shell nanostructures have recently received much attention for their enhanced thermal stability. They show great potential in the field of catalysis, as reactant gases can diffuse in and out of the porous shell while the core particle is protected from sintering, a process in which particles coalesce to form larger particles. Sintering is a large problem in industry and is the primary cause of irreversible deactivation./nDespite the obvious advantages of high thermal stability, porous core-shell nanoparticles can be developed to have additional interactive properties from the combination of the core and shell together, rather than just the core particle alone. This dissertation focuses on developing new porous core-shell systems in which both the core and shell take part in catalysis./nTwo types of systems are explored; (1) yolk-shell nanostructures with reducible oxide shells formed using the Kirkendall effect and (2) ceramic-based porous oxide shells formed using sol-gel chemistry. Of the Kirkendall-based systems, Au@FexOy and Cu@CoO were synthesized and studied for catalytic applications. Additionally, ZnO was explored as a potential shelling material. Sol-gel work focused on optimizing synthetic methods to allow for coating of small gold particles, which remains a challenge today. Mixed metal oxides were explored as a shelling material to make dual catalysts in which the product of a reaction on the core particle becomes a reactant within the shell.

Advisor: Alivisatos, Paul
The Turn to the Political: Post-Marxism and Marx's Critique of Politics

Recent political theorists have emphasize the importance of the concept of the political, and criticized earlier theorists, especially Marxists, for dissolving the political in other concepts, especially reducing politics to economics. Marx, however, did not reduce the political to the economic, but instead subjected the category of the political to a sophisticated critique, in his early work, which influenced the direction of all his later work. Following Marx's critique of politics, this dissertation argues against the autonomy of the political, and proposes a political theory which sees politics as inseparable from a wider social and economic context./nThe dissertation begins with a discussion of four post-Marxist authors, Badiou, Laclau, Mouffe, and Rancière, who respond to perceived problems in Marxism (particularly the Marxism of Althusser) by emphasizing the autonomy of the political. It then traces Marx's critique of politics throughout his work, beginning with his early identification of the separation of the political and the economic as a "practical illusion," a kind of appearance which is not simply a pretense or error, but which has material effects. The dissertation then discusses how Marx developed this account of the relationship between politics and appearance in the Eighteenth Brumaire and Communist Manifesto, before turning to Marx's most sophisticated analysis of the logic of appearance, the identification of commodity fetishism in Capital. The dissertation concludes with a discussion of the implications of Marx's critique of politics for contemporary political theory./nThe analysis of post-Marxism and of Marx in this dissertation, then, shows the limitations of the turn to the political, and the ways in which a focus on the political as an autonomous sphere produces a political theory that is incapable of understanding the richness of politics. The reading of Marx also demonstrates a better approach to political theory, one which, through an analysis of politics as appearance, reveals the many intersections and imbrications of the apparently political and the supposedly non-political. In many ways, this analysis is only the beginning, the announcement of a further research program which would found political theory not on the political alone, but on politics, economics, aesthetics and all the other fields into which our discussion of political concepts might take us. Such an investigation could draw on Marxist and non-Marxist theories, being limited neither by the purified notion of politics of post-Marxist, nor by the parochial textualism of too much Marxist theory. What this dissertation proposes is a reconceptualization of political theory which, by rejecting the autonomy of the political, is able to pay full attention to the richness of politics.

Advisor: Brown, Wendy
Electrical and Optical Enhancement in Internally Nanopatterned Organic Light-Emitting Diodes

Organic light-emitting diodes (OLEDs) have made tremendous technological progress in the past two decades and have emerged as a top competitor for next generation light-emitting displays and lighting. State-of-the-art OLEDs have been reported in literature to approach, and even surpass, white fluorescent tube efficiency. However, despite rapid technological progress, efficiency metrics must be improved to compete with traditional inorganic light-emitting diode (LED) technology. Organic materials possess specialized traits that permit manipulations to the light-emitting cavity. Overall, as demonstrated within, these modifications can be used to improve electrical and optical device efficiencies. This work is focused at analyzing the effects that nanopatterned geometric modifications to the organic active layers play on device efficiency./nIn general, OLED efficiency is complicated by the complex, coupled processes which contribute to spontaneous dipole emission. A composite of three sub-systems (electrical, exciton and optical) ultimately dictate the OLED device efficiency. OLED electrical operation is believed to take place via a low-mobility-modified Schottky injection process. In the injection-limited regime, geometric effects are expected to modify the local electric field leading to device current enhancement. It is shown that the patterning effect can be used to enhance charge carrier parity, thereby enhancing overall recombination. Current density and luminance characteristics are shown to be improved by OLED nanopatterning from both the model developed within and experimental techniques./nNext, the optical enhancement effects produced by the nanopatterned array are considered. Finite-difference time-domain (FDTD) simulations are used to determine positional, spectral optical enhancement for the nanopatterned device. The results show beneficial effects to the device performance. The optical enhancements are related to the reduction in internal radiative quenching (improved internal quantum efficiency) and improvement in light extraction (improved outcoupling efficiency). Furthermore, the electrical model is used to construct a positional radiative efficiency map that when combined with the optical enhancement reveals the overall external quantum efficiency enhancement.

Advisor: Mao, Samuel S
Greif, Ralph
The Politics of Experience: Peace Corps Volunteers, Vietnam Veterans, and American Internationalism, 1961 - 1985

This dissertation argues that knowledge based on personal experience came to rival accredited knowledge in American foreign policymaking during the Vietnam War. This shift toward experiential authority transformed American political culture and foreign policy. First-person narratives of Americans who lived abroad became crucial sources for popular understanding and congressional decision-making. In turn, the authority of personal experience in discussions of foreign policy helped enable a movement away from the global projects of development and containment and toward human rights around the world./nFocusing on Vietnam veterans and Peace Corps volunteers, this dissertation explores the uses to which these groups put their on-the-ground experience when they spoke publicly about American foreign policy issues. By examining veteran testimony before the Senate Committee on Foreign Relations and returned Peace Corps volunteer activism about American policy in the developing world, this study finds that the authority of personal experience acquired great persuasive power in the context of a nation reeling from the failure of its foreign policy abroad and wary of its political leaders' integrity and ability. This crisis in accredited authority and consequent shift toward experiential authority had lasting impacts both on American political culture and the foreign policies Americans pursued in the post-Vietnam era. By examining a distinct language of political participation, this study provides a new lens through which to interpret the events of the late 1960s and early 1970s.

Advisor: Sargent, Daniel J
A Mass Spectrometry Study of Isotope Separation in the Laser Plume

Accurate quantification of isotope ratios is critical for both preventing the development of illicit weapons programs in nuclear safeguards and identifying the source of smuggled material in nuclear forensics. While isotope analysis has traditionally been performed by mass spectrometry, the need for in situ measurements has prompted the development of optical techniques, such as laser-induced breakdown spectroscopy (LIBS) and laser ablation molecular isotopic spectrometry (LAMIS). These optical measurements rely on laser ablation for direct solid sampling, but several past studies have suggested that the distribution of isotopes in the ablation plume is not uniform./nThis study seeks to characterize isotope separation in the laser plume through the use of orthogonal-acceleration time-of-flight mass spectrometry. A silver foil was ablated with a Nd:YAG at 355 nm at an energy of 50 μJ with a spot size of 71 μm, for a fluence of 1.3 J/cm2 and an irradiance of 250 MW/cm2. Flat-plate repellers were used to sample the plume, and a temporal profile of the ions was obtained by varying the time delay on the high-voltage pulse. A spatial profile along the axis of the plume was generated by changing the position of the sample, which yielded snapshots of the isotopic composition with time. In addition, the reflectron time-of-flight system was used as an energy filter in conjunction with the repellers to sample slices of the laser plasma orthogonal to the plume axis./nMass spectrometry of the plume revealed a fast ion distribution and a slow ion distribution. Measurements taken across the entire plume showed the fast 109Ag ions slightly ahead in both space and time, causing the 107Ag fraction to drop to 0.34 at 3 μs, 4 mm from the sample surface. Although measurements centered on the near side of the plume did not show isotope separation, the slow ions on the far side of the plume included much more 109Ag than 107Ag. In addition to examining the isotope content of the ablation plume, this study has developed a mass spectrometry characterization technique that may be useful for investigating chemical reactions during laser ablation.

Advisor: Mao, Samuel S
Greif, Ralph
Access and the Choice of Transit Technology

An urban transit system can be made more cost-efficient by improving the access to it. Efforts in this vein often entail the provision of greater mobility, as when high-speed feeder buses are used to carry commuters to and from trunk-line stations. Other efforts have focused on the creation of more favorable land-use patterns, as occurs when households within a Transit-Oriented Development (TOD) are tightly clustered around trunk stations. The efficacy of these mobility and land-use solutions are separately examined in the present work. To this end, continuum approximation models are used to design idealized transit systems that minimize the generalized costs to both the users and the operators of those systems./nThe assessments unveil how the choice of rolling-stock for the trunk-line portion of a transit network can be influenced by its access mode. If transit is accessed solely (and slowly) on foot, then the optimal spacings between lines, and between the stations along those lines, are small. This can place capital-intensive rail systems at a competitive disadvantage with transit systems that feature buses instead. When access speeds increase, the optimal spacings between lines and stops expand as well. Hence, if accessed by fast-moving feeder buses, Metro-rail or bus-rapid transit can become preferred trunk-line options./nBy comparison, the influence of altered land use patterns brought by TODs was found to be less dramatic. While clustering households around Metro-rail stations justifies larger spacings between the stations, it yields only modest reductions in generalized costs because the larger spacings penalize transit users who reside outside of the TODs.

Advisor: Cassidy, Michael
Madanat, Samer
Executive Functions in Young Adult Females with and without ADHD: Longitudinal Development and Associations with Impairment

Attention-deficit/hyperactivity disorder (ADHD) is a male predominant neurodevelopmental disorder, with the unfortunate consequence that boys and men constitute the focus of the bulk of the extant research (Gaub & Carlson, 1997; Hinshaw & Blachman, 2005). Many studies include entirely male samples; others include too few females to conduct meaningful analyses within all-female subsamples. Thus, very little research has focused specifically on girls with this disorder, particularly with respect to neuropsychological variables. It is important to understand these topics in females, including specific neuropsychological mechanisms underlying both typical and atypical development, in order to determine core underlying mechanisms as well as to guide diagnostic and treatment-development efforts. In the present study, I utilized data from a longitudinal study of girls with and without ADHD. This investigation of a large, well-characterized, and diverse female sample currently consists of data from three time points, the first collected in childhood (ages 6-12); the second collected during adolescence (ages 12-18); and the third collected during late adolescence/young adulthood (ages 17-25). This investigation had three main aims: (1) to determine whether girls with and without childhood-defined ADHD show improvements in neuropsychological functioning over time (from childhood to adolescence to young adulthood) and whether the developmental trajectory is different for girls with ADHD versus comparison girls; (2) to assess differences in neuropsychological functioning in those whose ADHD symptoms have persisted into young adulthood versus those whose ADHD symptoms have remitted; and (3) to determine whether neuropsychological performance in adolescence mediates associations between childhood ADHD symptoms and young adult functional outcomes. Results indicated that individuals with childhood-diagnosed ADHD - who had the greatest EF impairments in childhood - showed the greatest improvement from childhood to adolescence to young adulthood relative to comparisons on some measures of EF, but similar or slower rates of development on others, controlling for key baseline comorbidities. The ability of ADHD persistent-remitted status to predict change in EF abilities was lacking, and there was no evidence of any association between improvement in EF abilities and remitted ADHD status. Mediation analyses indicated that adolescent EF mediated associations between ADHD symptoms and young adult academic achievement abilities, but no other outcomes. Such findings suggest the potential importance of EF abilities as a treatment target in ADHD in order to prevent academic difficulties.

Advisor: Hinshaw, Stephen P
Tuning Hardware and Software for Multiprocessors

Technology scaling trends have enabled the exponential growth of computing power. However, the performance of communication subsystems scales less aggressively. This means that an application constrained by memory/interconnect performance will not be able to use the available computing power efficiently---in fact, technology scaling will make this efficiency even worse. This problem can be alleviated if algorithms minimize communication. To this end, we describe communication-avoiding algorithms and highly optimized implementations of a sparse linear algebra kernel called ``matrix powers''. Results show up to 2.3x improvement in performance over the naive algorithms on modern architectures. Our multi-core implementation of matrix powers enables us to develop a communication-avoiding iterative solver for sparse linear systems which is up to 2.1x faster than a conventional Generalized Minimal Residual method (GMRES) implementation./n/nAnother problem plaguing the supercomputer industry is the power bottleneck---power has, in fact, become the pre-eminent design constraint for future high-performance computing systems which is why computational efficiency is being emphasized over simply peak performance. Static benchmark codes have traditionally been used to find architectures optimal with respect to specific metrics. Unfortunately, because compilers generate sub-optimal code, benchmark performance can be a poor indicator of the performance potential of architecture design points. Therefore, we present hardware/software co-tuning as a novel approach for system design. In co-tuning, traditional architecture space exploration is tightly coupled with software auto-tuning for delivering substantial improvements in area and power efficiency. We demonstrate co-tuning by exploring the parameter space of a Tensilica's Xtensa-based multi-processor running three of the most heavily used kernels in scientific computing, each with widely varying micro-architectural requirements: sparse matrix vector multiplication, stencil-based computations, and general matrix-matrix multiplication. Results/ndemonstrate that co-tuning improves hardware area and power efficiency by up to 3x and 2.4x respectively.

Advisor: Wawrzynek, John
New approaches to robustness and learning in data-driven portfolio optimization

We develop two new approaches to robustness and learning in data-driven portfolio optimization, a problem that is well-known for sensitivity to model assumptions and data variability./nFirst, we consider the data-driven mean-CVaR problem. For this problem, we introduce and investigate performance-based regularization (PBR), a generalization of standard regularization techniques used in statistics and machine learning, and an alternative to worst-case approaches to improving solution robustness. We assume the available log-return data is iid, and detail the approach for two cases: nonparametric and parametric (the log-return distribution belongs in the elliptical family). We derive the asymptotic behavior of the nonparametric PBR solution, which leads to insight into the effect of penalization, and justification of the parametric PBR method. We also show via simulations that the PBR methods produce efficient frontiers that are, on average, closer to the population efficient frontier than the empirical approach to the mean-CVaR problem, with less variability./nNext, we consider portfolio optimization under parameter uncertainty, and propose optimizing a relative regret objective. Relative regret evaluates a portfolio by comparing its return to a family of benchmarks, where the benchmarks are the wealth of fictitious investors who invest optimally given knowledge of the model parameters, and is a natural objective when there is concern about parameter uncertainty or model ambiguity. We analyze this problem using convex duality, and show that it is equivalent to a Bayesian problem, where the Lagrange multipliers play the role of the prior distribution and the learning model involves Bayesian updating of these Lagrange multipliers/prior. This Bayesian problem is unusual in that the prior distribution is endogenously chosen by solving the dual optimization problem for the Lagrange multipliers, and the objective function involves the family of benchmarks from the relative regret problem. These results show that regret is a natural means by which robust decision making and learning can be combined.

Advisor: Lim, Andrew
El Karoui, Noureddine