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Boundary Deformations of Elliptic Eigenvalue Problems
Get PDFThis thesis explores spectral properties of elliptic eigenvalue problems on domains subject to boundarydeformations and is dedicated to two main problems that provide deeper insight into the sensitive relationshipbetween domain geometry and eigenfunction behavior. In Chapter 2, we study the effects of a domain deformation to the nodal set of Laplacian eigenfunctionsdefined on a rectangle and corresponding to an eigenvalue of multiplicity 2. We establish geometric properties,such as number of nodal domains, presence of crossings, and boundary intersections, of nodal sets for a largeclass of boundary deformations and analyze how these properties change for small perturbations. We showthat internal crossings of the nodal set break under generic deformations and obtain estimates on the locationand regularity of the nodal sets on the perturbed rectangle. The contents of Chapter 2 have been published inAnnales Mathematiques du Québec. In Chapter 3, we study the eigenvalues and eigenfunctions of a differential operator, Dε , that governsthe asymptotic behavior of an unsupervised learning algorithm known as Locally Linear Embedding. Whendefined over a compact Riemannian manifold with boundary, the differential operator is elliptic over a movingsubmanifold of codimension 0. We show that a natural regularity condition on the eigenfunctions imposes aconsistent Neumann-type boundary condition on the elliptic region and use the Frobenius method to estimatepointwise behavior. We then determine the limiting sequence of eigenvalues analytically and compare themto numerical predictions. The contents of Chapter 3 are available at https://arxiv.org/abs/2501.09572. Finally, in Chapter 4, we explore the spectral behavior of a differential operator that, up to a local signchange, resembles Dε on the interval. The sign change is applied to terms that are localized in a boundarylayer, and we seek to understand how it affects the possible eigenfunctions. Contrasting Chapter 3, we showthat eigenfunctions of this operator solve a singular Sturm-Liouville equation and share a Dirichlet boundarycondition on the elliptic region. Using asymptotics of hypergeometric functions, we then determine thelimiting sequence of eigenvalues and compare to that of Dε .Doctor of Philosoph
The Political Economy of Social Investment in Latin America
Get PDFThis dissertation examines the politics of social investment, focusing on the demand and supply sides of education, labor, and housing policies in Latin America. The theoretical framework is based on the claim that distributive policy preferences are deeply influenced by ideological and economic factors that can lead citizens to reevaluate existing policies. I analyze the conditions under which low-income beneficiaries demand investment policies, how governments incorporate these demands into their platforms, and how they can expand such policies. I do so using a mixed-methods approach that includes observational data, survey experiments, focus groups, text analysis, and interviews. The findings indicate that citizens’ distributive preferences are shaped by their economic conditions. When low-income individuals perceive existing cash transfers as ineffective, their preference for investment policies increases over additional cash assistance. Additionally, I show that both left- and right-wing governments implement investment policies but frame them differently: left-leaning leaders emphasize social inclusion, while right-leaning leaders highlight productivity. These ideological framings play a crucial role in building the cross-class coalitions necessary for policy expansion, as they influence citizens’ willingness to support taxation for social investment. By integrating evidence from Argentina, Brazil, Chile, and Uruguay, this dissertation contributes to debates on welfare state development, political communication, and the political economy of social investment in developing democracies.Doctor of Philosoph
COLLEGE ATHLETE MENTAL HEALTH: UNDERSTANDING THE ROLES OF TEAM CULTURE, NIL, AND SOCIAL MEDIA
Get PDFCollege athletes are a vulnerable population to mental health concerns due to additional stressors that typical college students do not face. A conceptual analysis of the underlying systems that contribute to these issues is lacking. Therefore, this work presents a conceptual model of the mental health landscape of college athletics based on Bronfenbrenner’s (1986) socio-ecological model (SEM). This work also provides a key focus on social media embedded into the lives of college athletes, guided by self-presentation theory (Goffman, 1959). Interviews were conducted with 17 former college athletes, revealing the following themes: (1) The Institution: NCAA Polices, Culture, and Resource Gaps, (2) Interpersonal Complexities: Influence of Coaches and Teammates, (3) Internal Battles: Demands, Mental Health Struggles, and Stigma, and (4) Personal Identity Struggles of College Athletes and Transition Out of Sport. This study offers contributions to theory and practice. The model guides future research studying unique organizational systems in and beyond athletics. The interviews inform future policies within college athletics to take a more holistic approach.Master of Art
Code Phoenix: A burn notification alert system
Get PDFSevere burn injuries as defined by the American Burn Association (ABA) often presentunique challenges in timely care delivery due to the delayed onset of hemodynamic instability.This delay can result in prolonged time to burn provider assessment, which is the mostimportant factor in accurate total body surface area estimation and accurate fluid resuscitation.These are the key controllable factors in improving outcomes for patients with burns. Thisdelay was thrown into greater relief after the revision of the American College of Surgeons Redand Yellow trauma criteria removed burn injuries as a qualifying mechanism of injury. Toaddress this issue, the "Code Phoenix" protocol was developed by the Burn Intensive Careteam, with collaboration from the Emergency Department (ED) and trauma department. Thiswas implemented to streamline communication between the ED and the Burn ICU, aiming toreduce delays in burn team notification. This quality improvement project utilized the Plan-Do-Study-Act (PDSA) cycles from the Agency for Health Care Quality to assess the effectiveness ofthe new burn-specific alert system. Data collected over a 90-day period showed a clinicallysignificant reduction in the time from patient arrival to Burn ICU team notification, from anaverage of 50 minutes pre-implementation to 34 minutes post-implementation. Stakeholderfeedback indicated strong support for the new protocol, with 89% of respondents finding thecriteria easy to locate and 95% finding them easy to understand. Although statisticalsignificance was not reached due to the small sample size, the results suggest that the CodePhoenix protocol improved the timeliness of burn provider notifications, which is expected toenhance patient outcomes. Future studies are recommended to explore the impact on patientmorbidity, mortality, and the potential for extending the protocol to prehospital care andtransferring institutions.Doctor of Nursing Practic
Theory of Asset Price Bubbles and its Effects on Macro-economy
Get PDFThis dissertation investigates how asset price bubbles arise in the modern macroeconomic theory. The first chapter is related to the existence condition of asset price bubbles and its dynamic stability. Asset price bubbles have been widely considered as an economically fragile phenomenon. Specifically, in a wide variety of models with asset price bubbles, there exists a continuum of bubbly equilibrium that converges to a bubble-less steady state, and there is a unique bubbly equilibrium converging to a bubbly steady state. This paper shows that if the agents' risk aversion is sufficiently low, a standard model with asset price bubbles generates a bubbly steady state where all bubbly equilibria converge to the bubbly steady state. In other words, the bubbly steady state is dynamically stable. The stable bubble arises when asset price bubbles create strong crowding-in effects through the net worth effect, while the crowding-out effects by bubbles through the equilibrium interest rate rise are relatively limited. The second chapter investigates a mechanism in which a burst of asset bubbles induces financial panic and bank run. In an economy with heterogeneous investment opportunities and financial constraints, a bubble asset, defined as an asset with intrinsically no fundamental value, can have a positive price in the equilibrium, because the positive price is supported by the liquidity premium. In such a circumstance, bubble asset prices strongly correlate with the banking sector's liquidity premium. The price correlation helps provide ample liquidity during periods of financial distress. Consequently, all depositors anticipate no bank run phenomenon even under financial distress. However, once bubbles burst, the role of liquidity provision suddenly disappears. As a result, depositors anticipate a severe liquidity shortage in the banking sector. Combined with excessive leverage in the bubble economy, the bank's liquidation value at a fire sale price could be below the debt amount, prompting depositors to choose the bank's liquidation.Doctor of Philosoph
The Impact of Added Flavor on Consumption via Hedonic Eating
Get PDFThe role of added flavor in hedonic eating and overconsumption is of growing interest, particularly in ultra-processed foods (UPFs). This study examined whether added flavor influences intake through hedonic mechanisms and how liking and impulsivity affect consumption. Thirty-eight adults (50% female, 50% male) participated in a taste test and ad libitum intake phase with four snack types (potato chips, ice cream, gummy bears, soda) in flavored and unflavored conditions. A two-way repeated-measures ANOVA revealed significant effects of flavor and snack type on intake (p < 0.001). Unflavored chips and ice cream were consumed more than their flavored counterparts, whereas flavored gummy bears were consumed more than unflavored. Impulsivity had no effect. Findings suggest added flavor does not always increase intake but may enhance consumption of bland foods. Future research should refine unflavored control selection and examine the role of familiarity in added flavor-driven hedonic eating and consumption.Master of Scienc
In Miniature A Study of Craft and Play in the Wargaming Industry
Get PDFThis dissertation employs qualitative and theoretical methods to analyze the relationship between craft and industry in the miniatures wargames industry in and around Nottingham, UK. It asks fundamental questions about how craft is defined and how craft communities operate. This project particularly attends to questions of communication and meaning-making at miniatures studios, attending to questions of practice, subcultural currency, masculinity, and negotiations between practitioners and British history. Lastly, it attends to matters of technological change within the miniatures wargames industry as new digital technologies and analog practices expand definitions of and accessibility to craft.Doctor of Philosoph
Sampling Imbalanced Data with Bilevel Optimization
Get PDFImbalanced datasets, where minority classes are underrepresented compared to majority classes, present significant challenges in machine learning, often leading to biased models and poor classification of critical minority data. This dissertation introduces two novel sampling methods grounded in bilevel optimization to address these issues. The first method, Majority Undersampling with Bilevel Optimization (MUBO), improves classification without relying on any synthetic minority data by strategically undersampling majority data to enhance feature diversity and reduce class overlap. While effective on larger datasets, MUBO's performance declines with smaller datasets due to too few minority datapoints. To address these limitations, the second method, Multi-Objective Optimization for Data Sampling (MOODS), integrates a small amount of carefully selected synthetic data generated via SVM-SMOTE. This approach ensures that synthetic samples increase minority class diversity while also using bilevel optimization to avoid harmful overlap. A key contribution of this work is a novel metric designed to quantify the balance, diversity, and overlap of training datasets - critical properties for robust model performance. This ` balanced diversity metric' provides a framework for evaluating and comparing sampling methods, moving beyond traditional performance metrics like scores to offer deeper insights into the quality of training data. Experimental results across multiple benchmark datasets demonstrate that both methods, alongside the new evaluation metric, outperform existing techniques, offering robust, generalizable solutions for imbalanced data classification.Doctor of Philosoph
Mutualization as Contested Terrain: A Money View of Regeneration Finance in Colombia
Get PDFThis thesis analyzes Colombian monetary policy between 1880 and 1904, using the theoretical frameworks of the Money View and Regulation School political economy. It highlights opposition by a specific fraction of capital — import and export interests — to the system of paper money inaugurated by Colombia’s government during the period. While traditional monetary theory expects depreciating currency to benefit exporters (Helleiner 2002), exporters allied with importers to reject this regime of paper money, favoring a return to the gold standard. An import-export bloc mobilized against this regime by freely stipulating contracts in gold, speculating on paper currency, and withholding exports. From a Money View perspective, these acts represent major challenges to the contingent functioning of a monetary system. By paying attention to the interlocking institutional balance sheets that comprise monetary systems, this thesis alights on the import-export bloc as a key node in the network of producing Colombian monetary liquidity.Master of Art
THE E IN SPORTS: THE PLATFORMIZATION OF PROFESSIONAL GAMING
Get PDFThis dissertation examines the development of the professional gaming industry—popularly known as esports—between 2009 and 2020. In contrast to sport-centric frameworks to understanding professional gaming, this dissertation utilizes the framework of platformization of cultural production: the penetration of economic and infrastructural extensions of online platforms into the web, affecting the production, distribution, and circulation of cultural content. Using this framework, I consider how video game publishers, especially Valve, Activision-Blizzard, and Riot Games, sought to transform the underlying technical, legal, and financial arrangements that undergird professional gaming. In particular, I illustrate how, in the 2010s, and like other sectors of cultural production, professional gaming became subject to novel forms of platform governance, multisided markets, and infrastructure. It is argued that esports ought to be understood as an effort to create an articulation of sporting that is aligned with the financial and technical logics of digital platforms.Doctor of Philosoph