VictorJuiz/thesis huggingface dataset:
Assessing the Evolution and Impacts of Brazilian Hydropower
Keywords: Hydropower
Brazil
Environmental Impact Assessment
Sustainable development
Text
Thesis

For over a century, hydropower has represented the largest source of Brazilian electricity, supplying more than three-quarters of power today. This paper traces Brazil’s reliance on hydropower over the 20th century alongside a growing concern for the impacts of industrialization on the environment, which culminated in the implementation of the Environmental Impact Assessment (EIA) in 1988. The adoption of the EIA was a defining moment for Brazilian environmental regulation. It required detailed analysis of proposed projects and allowed officials to make informed decisions regarding environmental and social impacts. This paper conducts a review of the EIA system, including both its global and Brazilian implementation, its influence on hydropower projects, and the fundamental challenges it faces as a regulatory tool. The theoretical evaluation of the EIA is expanded on through the comparison of Brazil’s largest Amazonian hydropower projects, the Tucuruí Dam, constructed before the EIA, and the Belo Monte Dam, constructed after. This comparative analysis demonstrates that the EIA has significantly altered the planning of hydropower dams, while also highlighting flaws in the EIA process that undermine its ability to mitigate environmental and social impacts. Although it is possible to reduce certain impacts associated with hydropower, this study suggests that issues such as deforestation, flooding, mass-displacement, loss of ecosystems, greenhouse gas emissions, and impacts on indigenous peoples are virtually unavoidable when constructing mega-dams within the Amazon region. These results recommend a renewed focus on alternative energy sources and necessitate careful consideration of hydropower’s role in Brazilian sustainable development.
Assessing the Impact of the COVID-19 Pandemic on Health and Social Wellbeing in Low-socioeconomic Status Seniors
Keywords: Older people
Older people > Care
COVID-19 Pandemic (2020-)
Health
low-income
Text
Thesis

The COVID-19 pandemic has presented challenges for all age groups, with older adults being disproportionately affected as some of the most vulnerable people in society. Low-socioeconomic status (SES) older adults experience further challenges surrounding mental health, social wellbeing, and food insecurity. Given the unprecedented nature of the pandemic, it is important to understand the extent of the impact COVID-19 has had on this population, with the ultimate goal of identifying gaps in care services for low-SES seniors and opportunities for improved programming. In this cross-sectional mixed methods study, 93 low-SES seniors living in two affordable housing communities in the East Bay Area were surveyed. Around 76% of participants were aged 70 or older, 72% were female, and 58% identified as non-Hispanic White. In the printed 6-page questionnaire, participants were asked to reflect on their experiences prior to the pandemic and compare them to their present state, one year into the pandemic. Following survey collection, a subset of five respondents was interviewed over the phone to identify key themes. Statistical analyses on the survey data showed that as compared to pre-COVID-19, participants indicated a significant decline in their diet and nutrition, physical health, sleep quality, mental health, and social networks. In terms of social wellbeing, there was a decline in feelings of connectedness to one’s community and time spent eating in the company of others, and an increase in feelings of loneliness and isolation. However, perceptions of general support and having people to turn to did not decline. Interview data generally confirmed survey findings, with participants, two of whom had lost partners during the pandemic, frequently citing feelings of anxiety and intense isolation from friends. Finally, participants indicated a need for better COVID-19 informational services and programming. These results reveal the need for increased safe social programming and outlets for low-SES seniors who often suffer from poorer mental and physical health at baseline. The findings help reveal the changing needs of seniors during this challenging time and urge the development of solutions to improve health and wellbeing in the low-SES senior population, especially during periods of crisis involving social restrictions.
Atom manipulation-enhanced quasiparticle interference : accessing band structure, pseudospin and landau levels
Keywords: Applied Physics.

We have developed a method to investigate electron wavefunction using scanning tunneling microscope (STM). By imaging the defects in a condensed matter system, one can measure the properties of wavefunctions solely based on the density of state. For example, our method probes the electronic dispersion which is unavailable otherwise because the crystal momentum is encoded in the phase of a Bloch wave. We aim to study electronic structures with a spatial resolution that is beyond the reach of transport measurements which are limited by the size of electrical contacts, and optical methods which are limited by the size of optical beams. With atom manipulation, we further extend the method to study the inner degree of freedom of a wavefunction such as pseudospin. Electrons scatter differently upon defects with different symmetry. By designing the symmetry of defects using atom manipulation, we measure pseudospin and pseudospin selection rule based on the interference patterns of electron scattering around different defects. In this thesis, I first derive the relation between wavefunctions and scattering patterns from the first principle. This theory is then validated in experiments with quantum corrals that host well-understood particle-in-a-box wavefunctions. All experiments are conducted on nanostructures and lattices created by patterning the two-dimensional electronic surface state of the Cu(111) surface with carbon monoxide (CO) molecules. I then apply the method to several quantum materials, including graphene and quasicrystals, to study their electronic structures. Finally, I present studies that relate to quantum scattering of two-dimensional electrons, including a Fermionic Casimir force and an inverse scattering problem
Augmenting transition systems for scalable symbolic model checking
Keywords: Electrical Engineering.

Symbolic model checking is an important tool for finding bugs (or proving the absence of bugs) in modern hardware and software systems. Because of this, improving the ease of use, scalability, and performance of model checking tools and algorithms continues to be an influential research direction. In service of this goal, we present two tools followed by two novel techniques that expand the state of the art in symbolic model checking. The first tool, Smt-Switch, provides simple, uniform, and high-performance access to satisfiability modulo theories (SMT) solving for applications in areas such as automated reasoning, planning, and formal verification. We then present Pono, an open-source SMT-based model checker built on Smt-Switch. Pono is designed to be both a research platform for developing and improving model checking algorithms, as well as a performance-competitive tool to be used for academic and industry verification applications. Next, we use this infrastructure to prototype two model checking approaches that reduce the difficulty of a problem by modifying the given transition system model. First, we develop a framework for model checking infinite-state systems by automatically augmenting them with auxiliary variables, enabling quantifier-free induction proofs for systems that would otherwise require quantified invariants. We combine this mechanism with a counterexample-guided abstraction refinement scheme for the theory of arrays. Our approach can, in many cases, reduce inductive reasoning with quantifiers and arrays to quantifier-free and array-free reasoning. Second, we adapt partial order reduction (POR) for bounded model checking of synchronous hardware and introduce a novel technique that makes partial order reduction practical in this new domain. We demonstrate substantial performance improvements over unaltered bounded model checking with this technique, despite the conventional wisdom that POR is only applicable for asynchronous systems
Autonomous exploration of complex environments using active SLAM
Keywords: Aeronautics and Astronautics.

This dissertation develops a novel algorithm to perform autonomous surveys of unexplored 2D and 3D environments by extending the coverage path planning (CPP) literature to perform surveys using probabilistic coverage estimation. Robotic survey missions are designed to gather data from an environment and produce maps after the robot has been retrieved. The maps can take the form of 2D mosaics for planar terrain and 3D reconstructions for complex 3D environments. Survey missions of this form have applications in search-and-rescue, structural inspection, and scientific study. The goal of the survey mission is to achieve complete coverage, which is to have the robot observe every part of the environment before it is retrieved. Complete coverage becomes an issue when the robot does not have accurate localization, which can happen in environments that experience GPS-denial, e.g. underwater. In such environments, simultaneous localization and mapping (SLAM) is commonly used for localization. SLAM is an approach that corrects odometry with additional information in the form of terrain features. However, SLAM performance can degrade when there are insufficient features available, i.e. the terrain is feature-poor. There has been an evolution of algorithms that addresses the problem of surveying GPS-denied feature-poor terrain. State-of-the-art survey methods plan paths based on a coverage map, an estimate of which parts of the target area have been seen by the robot. This approach is called CPP. This thesis extends the CPP literature by developing an algorithm called SLAM directed by uncertainty-based node connections (SLAM-DUNC). For 2D surveys, SLAM-DUNC incorporates localization uncertainty into the coverage map to calculate a probability of coverage and plans paths based on this quantity. This extension enables probabilistic coverage estimation with cameras. For 3D surveys, paths are planned using a similar quantity called the probability of occupancy. SLAM-DUNC was demonstrated in simulation and on flight hardware, both in 2D and 3D environments. In 2D, SLAM-DUNC produced less false positive coverage compared to a non-probabilistic coverage method. For surveys in 3D environments, SLAM-DUNC produced an occupancy estimate that maintained accuracy and conservativeness in feature-poor terrain. An additional contribution is the improvement of a known localization algorithm called GraphSLAM to be more robust to false feature correspondences. These improvements are demonstrated using field data
Bayesian WIMP Parameter Inference for LXe TPCs
Keywords:  Department of Physics
LUX-ZEPLIN
LZ
Dark Matter
WIMP
Parameter Inference
Bayesian
Text
Thesis

Astrophysical evidence has long indicated the presence of a large percentage of invisible mass in the universe. The presence of this invisible and essentially collision-less mass, known as dark matter, has only been detected so far by its gravitational influence on astrophysical objects. Physicists have hypothesized that the Weakly Interacting Massive Particle (WIMP), a particle with mass in the GeV/c^2 range that interacts with baryonic matter at a weak scale, is a prime candidate for dark matter. If the WIMP hypothesis is correct, experiments on Earth can aim to discover them by looking for rare scatters off of atomic nuclei, which the LUX-ZEPLIN (LZ) experiment aims to do. LZ will use a liquid xenon Time Projection Chamber (LXe TPC) to detect elastic scatters off of xenon atoms caused by impinging WIMPs.
This thesis will introduce a generalized Bayesian statistical framework that is able to infer a WIMP's mass and spin-independent scattering cross section from simulated datasets. The framework will be developed around the LZ detector template, but will efficiently generalize to other similar LXe TPCs. We utilize this framework to generate and reconstruct several simulated experiments to highlight the statistical limitations on parameter inference posed when utilizing LXe TPCs. We also compare the change in reconstruction efficiencies caused by detectors of different masses and different background rates. Our reconstructions indicate that at low event rates, reduced backgrounds do not provide a significant gain in parameter resolution due to limitations posed by the WIMP scattering spectrum. On the contrary, increased detector sizes provide significant gains in statistical resolution. This indicates that for parameter inference purposes, future experiments should prioritize larger tonne-year detectors over reduced backgrounds.
Better optimization algorithms, moving beyond the classics
Keywords: Electrical Engineering.

This thesis studies several problems in optimization, from complexity-theoretic investigations to algorithm design questions. More specifically, (1) we give an iteration complexity-optimal algorithm for minimizing highly smooth convex function with Lipschitz continuous higher-order derivatives; (2) we investigate the complexity of optimizing convex, non-smooth functions with a highly parallel oracle, giving an algorithm with improved depth compared to the state-of-the-art and obtaining tighter lower bound characterizing when the parallel information helps compared to its fully sequential counterpart; (3) we propose an efficient sketching-based distributed algorithm with lightweight communication that can return high-accuracy solution for problem having composite structure. Through a better understanding of the fundamental barrier to problem efficiency on one hand, and the design of practical algorithms addressing requirement of modern computation model on the other, the thesis offers glimpse of the vast opportunities that the role of optimization remains to play for data science in either direction
Better Together? The Effect of U.S. Defense Industry Consolidation on Procurement Outcomes
Keywords:  Center for International Security and Cooperation
Defense
Procurement
Defense Industry Consolidation
Prime Contractors
Major Defense Acquisition Programs
Selected Acquisition Reports
Political Science
Thesis

Many policymakers believe that the consolidation of the U.S. defense industry is suboptimal, pointing to cost overruns, program delays, and technological problems with products. Meanwhile, economists believe that there may actually be efficiencies to be gained through consolidation in the defense industry and that therefore, its effects are not always negative. Utilizing a novel approach that combines economic and social science analyses, this thesis asks whether the consolidation of the U.S. defense industry has, in fact, increased costs and schedule delays of major defense acquisition programs and decreased private sector innovation and investment in innovation. Analysis of original datasets of Selected Acquisition Report summary table data from 2000-2020, schedule delay data compiled from GAO Annual Weapon’s Assessment reports since 2003, and company research and development spending of the prime contractors from 2000-2020 suggests that defense industry consolidation leads to negative effects on the cost and schedule of major defense acquisition programs as well as varied effects on private sector innovation/investment in innovation. Case studies of the F-35 and Ground Based Strategic Deterrent illustrate the dangers of the current states of the procurement process and the defense industry and also raise questions about the efficacy of current economic methodologies for analyzing cost growth of major defense acquisition programs. Policymakers should consider further examination of defense industry competition and M&A activity as well as the benefits of knowledge-based acquisition practices as the Department of Defense moves towards key decision points regarding legacy systems and the future of U.S. defense capabilities.
Beyond antibodies : high-throughput technologies for the development of synthetic affinity reagents with novel functions
Keywords: Chemical Engineering.

The accurate measurement of molecules is of crucial importance for a wide range of both basic and applied research applications. In particular, we need to measure the abundances and activities of biomolecules (proteins, carbohydrates, lipids, and nucleic acids) to understand their biological function which form the basis of life and diseases. To this end, we rely on affinity reagents, which are molecules that specifically bind to their target molecule. While antibodies are the current 'gold standard' of affinity reagents, there is a growing need for alternative reagents. Aptamers, often referred to as chemical antibodies, are short oligonucleotides that can bind to their targets with high specificity and affinity and can be engineered to perform novel functions that cannot be achieved with conventional antibodies. In this dissertation, I will discuss the development of three high-throughput technologies that enable the creation of synthetic DNA aptamers with novel functions. The first project describes a method to generate base-modified aptamers that can recognize protein glycoforms with exquisite specificity, which is challenging for antibodies. The second project describes the creation of a massively-parallel screen which enables the multiplexed selection of aptamers with extraordinary specificity that can distinguish metabolites with minimal difference in their chemical structure. Finally, I describe a screening technology for rapidly generating optically-responsive molecular switches from an existing aptamer which can be used directly as biosensors. As a whole, these studies provide valuable new tools that help address many of the challenges associated with the development of aptamers that are suitable for real-world applications
Beyond Big Cities: A Contextual Analysis of Human Trafficking in Salinas
Keywords: Human trafficking
Exploitation
Legislative Policies
Text
Thesis

For her capstone project, Lina Karamali focused on issues of human and labor trafficking in California, specifically within the city of Salinas. Driven by a deep concern for the rise of human trafficking cases and statistics, Lina’s project examines legislative measures that have historically aimed to address this issue but with varying outcomes. Using Salinas as a critical case study, Lina demonstrates how anti-trafficking policies and laws can often overlook rural cities, like Salinas, that while not very populous, remain a hub of human trafficking activity. Through her research, Lina hopes to offer policy recommendations that may apply to places like Salinas, which share some commonalities with larger urban centers but also present challenges unique to smaller, rural communities that are agricultural and more isolated.
Beyond enhancer-promoter contact : leveraging deep learning to connect super-resolution DNA traces to transcription
Keywords: Genetics.

Chromatin architecture plays an important role in gene regulation. Recent advances in super-resolution microscopy have made it possible to measure chromatin 3D structure and transcription in thousands of single cells. However, leveraging these complex datasets with a computationally unbiased method has not been achieved. In this dissertation, I present a deep learning-based approach to better understand to what degree chromatin structure relates to the transcriptional state of individual cells. Furthermore, I explore methods to "unpack the black box" to determine in an unbiased manner which structural features of chromatin regulation are most important for gene expression state. I apply this approach to the Optical Reconstruction of Chromatin Architecture dataset of the Bithorax gene cluster in Drosophila and show it significantly outperforms previous contact-focused methods. This work finds the structural information is distributed across the domain, overlapping and extending beyond domains identified by prior genetic analyses. Individual enhancer-promoter interactions are a minor contributor to predictions of activity
Beyond the Great Commission: Exploring the Diversity of Churches as Public Service Organizations
Keywords:  Urban Studies
church
service
public service
religious
Thesis

Christian churches in America have a strong commitment to serving the needy in their local communities; with the array of humanitarian services that churches offer today, the programming of these religious institutions increasingly resembles that of secular social service organizations. This is why churches as a homogenous organization type are consistently acknowledged in the literature on public service sectors for their collective impact on the public service fabric of the country. However, existing research has failed to acknowledge the circumstantial, organizational and theoretical distinctions between churches in the public service sector, nor how those distinctions are related to the diversity of ways in which churches engage with their communities. This study has two parts: the first is the analysis of interviews and census data to answer the questions, “What differences exist in how churches engage in public service? What factors correspond to these differences?” Findings show that the diversity of churches’ public service involvement comes primarily from ecological factors as well as church-level features and resource differences. Clergy visions for public service also play a role, except among three churches with similar intensities and modes of service but in which the theoretical views of service held by their clergy differ substantially. The second portion of this study further explores this finding among these three churches with the question, “What motivates clergy to do public service?” These motivations are understood through this study’s literary-historical analysis, as well as with observations of religious services and public service offerings. This array of research methods, despite its shortcomings, offers a promising direction for future research to evaluate churches and their leaders with more precise consideration for their variation as public service providers within their communities.