Browsing by Subject "summa cum laude"

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Abstract Syntax Contextualization Framework for Debugging Attribute Grammar Specifications
(2024) Feraru, Matthew;
In this thesis, we explore an aspect of debugging attribute grammar (AG) specifications. AG frameworks in themselves are high-level languages that allow a programmer to specify the syntax rules and semantics of a new programming language. The debugging of AG specifications is often done by interactively traversing abstract syntax trees (ASTs) that represent a parsed program in a metaprogram. The goal of such debugging is to find AG specifications with semantic rules that observe correct inputs but incorrect outputs—the possible bugs of AG specifications we consider. For large programs, ASTs may be difficult to understand by a programmer; graphically rendering ASTs in a debugging interface is challenging and still does not make it straightforwardly easy to understand ASTs relative to source code. Resultantly, we propose a textual way to use source and source-like syntax to represent the location of a navigated-to AST node relative to its position in an entire AST and highlight any notable features of the tree, such as the application of rewrite rules. This contextualization framework of abstract syntax tree nodes has been prototyped to work on Silver [1] specifications, but it is applicable to any AG framework since it only relies on the core features of the AG paradigm itself.
Analysis of Wind-Driven and Water-Driven Transportation of Gross Soilds in Urban Watersheds
(2023) Narváez, Natalie;
Watershed health is heavily influenced by urbanization and the export of associated pollutants such as nitrogen (N) and phosphorus (P) that leach into stormwater and accelerate the effects of eutrophication. In urban watersheds, gross solids materials have been shown to contribute significant amounts of P to stormwater runoff. Positive correlations have been identified between precipitation patterns and influxes of gross solids to stormwater runoff. However, the role of wind-driven transportation as a contributor of organic material to urban stormwater solids remains poorly understood in comparison to the role of water-driven transportation. Wind-blown leaf litter has the potential to travel beyond the hydrologically connected areas that bound much of the research on stormwater solids. To address this knowledge gap, a detailed analysis was conducted on identifiable tree material from gross solids samples captured at two different rain garden sites - one parking lot site and one residential street site - with low canopy cover in the Minneapolis-Saint Paul metropolitan region in Minnesota, USA, to assess the possible mechanisms behind their deposition into the rain garden sites. It was assumed that material from outside of the watershed was transported by wind. Findings showed that material from outside the hydrologic watershed plays a significant role in the prevalence of gross solids, with an average percentage of 29% of material from outside the watershed and 71% from inside the watershed. Material from outside the watershed represented the majority of identified material from the residential street site. Material from within the watershed appeared to rise and fall along with precipitation patterns while material from outside the watershed appeared to fluctuate opposite them, suggesting that material from outside the watershed is more dominant in dryer conditions. Results of this study suggest that material from outside the watersheds represents a significant portion of leaf litter and other plant materials that constitute the organic fraction of urban stormwater solids.
Busted: Executive Misconduct and Its Implications for a Firm's Tax Avoidance
(2023) Manna, Jackson;
The title of ‘CEO’ confers upon an individual considerable influence over his or her organization, from corporate culture to financial reporting. Prior research has documented that the individual acting as CEO has a significant impact on a firm’s tax planning activities – the degree to which tax is avoided and the aggressiveness of tax positions taken. With such power comes substantial responsibility – particularly in recent years, corporate CEOs have faced heightened scrutiny and accusations regarding personal behaviors outside of work. This thesis analyzes whether an accusation of personal misconduct against a CEO has a significant impact on the tax planning activities of his or her firm. Tax avoidance is an appropriate means through which to measure the impact that personal misconduct allegations against the CEO have on the business-related aspects of a company. In the context of ethical misconduct and the allegations that follow, tax avoidance is unique from other financial metrics in that it has strong ethical considerations. It may follow, therefore, that decisions made by a firm in light of alleged ethical violations by the CEO will be reflected in the firm’s tax planning. I hypothesize that perceived scrutiny against a CEO for personal misconduct will motivate the firm to perform less aggressive tax avoidance in the years that follow. I examine this hypothesis through a multi-year event study which compares the change in tax avoidance for firms that experienced a CEO “violation event” against firms that did not. Through correlation and regression analyses, my results do not show significant evidence that personal misconduct allegations against a CEO influence a firm’s level of tax avoidance. However, there still exists strong motivation for further research.
Dynamic Modelling and Control of Exoskeleton Gantry Robot
(2024) Hajare, Eesha;
This thesis presents the development and analysis of dynamic model of an exoskeleton gantry used to perform brain studies in freely moving mice for neuroscience experiments. The dynamic of model of the exoskeleton gantry comprised of X and Y stages is developed, and relevant system characteristics like bandwidth and stability are studied using theoretical model to predict the system behavior. The predicted bandwidth of the open loop system is found to be 1.9Hz and 3.8Hz for the Stage X and Y respectively using the theoretical model. The open loop system was further verified experimentally using LABVIEW and an experimental model was generated using computer software. According to the experimental results, the open-loop bandwidth of the X and Y stages was found to be 2.3 Hz and 2.76 Hz respectively. Furthermore, the open loop system is also used to gauge the stability of the closed-loop and the gain and phase margin are studied for the same purpose. According to theoretical studies, it is expected that the bandwidth of the open and closed loop system is expected to increase with a decrease in payload. The gain margin and phase margin are predicted theoretically and verified experimentally are well above the determined threshold of 2dB for gain margin and 450 for phase margin, this ensures the stability of the closed loop exoskeleton system. Moreover, the closed-loop bandwidth of the system is predicted using the theoretical model and an admittance control framework is proposed. The predicted closed-loop bandwidth for the exoskeleton gantry is found to be 19.2Hz and 16.4Hz for X and Y stages respectively. Furthermore, preliminary experimentation of the gantry with admittance control implementation suggests a closed loop bandwidth of 46Hz for Stage X.
Echoes of Identity: Reflections of Medea in Euripides' Bacchae
(2023) Tallarini, Amelia;
In Euripides’ Medea, one of his earliest surviving plays, we are faced with an unusual titular character. Medea is an extraordinarily powerful woman. Before her marriage to Jason, she had enabled him to reach heroic status through obtaining the Golden Fleece by her ruthless use of magical force. Despite this help which he received from her, Jason decides to divorce Medea, a barbarian woman, in favor of the princess of Corinth. The action of the play opens with Medea deciding what to do given this situation. As the plot unfolds, Medea takes on multiple roles. She starts as a victim of Jason’s abandonment. She then begins plotting vengeance upon him, and her initial plan includes murdering his future bride to get herself even with Jason. When she adds filicide into her revenge plot, Medea transgresses ordinary human boundaries and becomes a fiend. At the same time, however, she once again becomes a victim, but this time Medea is a victim of herself rather than of another. Medea’s personality is thus split, and her character contains contradictory elements both sequentially and simultaneously.
Experimental investigation of hybrid hydraulic fiber-reinforced actuators incorporating shape memory alloy
(2023) Brinkert, Kate;
The emerging field of soft robotics aims to offer solutions to many of the limiting factors present in traditional, “hard” robotics, such as complexity, material rigidity, and a lack of compliance. Fiber-reinforced elastomeric enclosure (FREE) actuators, including the well-researched McKibben pneumatic artificial muscle, are some of the most prevalent applications of this field due to their high power density and ability to actuate an entire structure with many degrees of freedom from a single pressure source. The kinematic behavior of these actuators is governed by the wrap architecture of the inextensible reinforcing fibers, and tailored motions can be achieved by simply adjusting the number of fiber families and their respective wrap angles. In this experimental investigation, eight hybrid hydraulic FREE prototypes are developed to explore the kinematic effects of incorporating a single wire of shape memory alloy (SMA) into various wrap geometries, including asymmetric configurations, which are previously unexplored. Changes in actuator length and rotation for each prototype are analyzed using discrete marker tracking as functions of the control variables of volumetric input and applied current, and kinematic behaviors are compared over various parameters of wrap geometry. Trends are established for the effects of wrap angles and their relationships to a generalized kinematic design space for FREES on the actuation potential of an incorporated fiber of SMA. Promising results are described for two additional proof of concept prototypes in an initial exploration of incorporating more than one SMA fiber into a hybrid actuator and expanding to more complex wrap configurations. This research demonstrates the capability of SMA to both augment passive actuator behavior and produce new forms of multimodal motion, providing a stepping stone towards more tailored applications of hybrid soft actuators.
FIST-nD: A tool for n-dimensional spatial transcriptomics data imputation via graph-regularized tensor completion
(2023) Atkins, Thomas K;
Functional interpretation of spatial transcriptomics data usually requires non-trivial preprocessing steps and other supporting data in the analysis due to the high sparsity and incompleteness of spatial RNA profiling, especially in 3D constructions. As a solution, we present a new software tool FIST-nD, Fast Imputation of Spatially-resolved transcriptomes by graph-regularized Tensor completion in n-Dimensions for imputing 3D as well as 2D spatial transcriptomics data. FIST-nD is implemented based on a novel graph-regularized tensor decomposition method, which imputes spatial gene expression data using 4-way high-order tensor structure and relations in spatial and gene functional graphs. The implementation, accelerated by GPU or multicore parallel computing, can efficiently impute high-resolution 3D spatial transcriptomics data within a few minutes. The experiments on three 3D Spatial Transcriptomics datasets and one 3D high-resolution Stereo-seq dataset confirm the high accuracy of the imputation by FIST-nD and demonstrate that the imputed spatial transcriptomes provide a more complete gene expression landscape for downstream analyses such as spatial gene expression clustering and visualizations.
Gertrude Bell: The Khatun Who Created Iraq?
(2020) Delahanty, Shannon;
This thesis will explore to what extent Gertrude Bell can be considered the architect of Iraq, considering her need to balance gender expectations and the personal beliefs of a 19th-century woman with interwar state-building apparatuses to create the Iraqi Mandate. By tying in her personal background as a historian and field trained archeologist, the structure and style of British museum culture and the state of global antiquities law can be compared to Bell’s approach to building the Baghdad Archeological Museum’s collection as a social and state shaping apparatus. Throughout this investigation, I will argue that her permanent place in political Iraqi history stems from her writing of the Review of the Civil Administration of Mesopotamia White Paper, her position as a political and social analyst, and her advisory relationship with King Faisal, while her efforts to create the definition of a centralized national identity through the national museum and public programming cements her in the state’s sociological history.
How Global Change Shapes Our World: Nitrogen and Salt Addition Affect Phytoplankton Morphology in a Small Freshwater Lake
(2024) Rodgers, Amanda;
Global environmental change has accelerated the deposition of nitrogen and salt into freshwaters. These changes affect the morphology of freshwater microbes, especially phytoplankton, which serve as primary producers for these ecosystems. Morphology reflects a microbe’s response to energy demands, selection, and environmental disturbance. In this pilot experiment, a handmade suspension device held samples from Cedar Bog Lake (East Bethel, MN) in three nitrogen conditions (17.6 mM NaNO3, 9 mM NaNO3, 0 mM NaNO3) crossed with two salt conditions (10 mM of NaCl or 0 mM of NaCl) plus a DI water control for BG11 media in triplicate on the surface of the lake for three weeks. I used flow cytometry to quantify community-level within-sample morphology using circle fit, area-based diameter (ABD) volume, aspect ratio, elongation, ABD area, compactness, particles/mL, and perimeter. A principal components analysis (PCA) revealed trait correlations between ABD area and ABD volume, and between circle fit, elongation, and compactness. A two-way analysis of variance (ANOVA) on the first three principal components (highly significant, accounting for 94.89% of the total variance) revealed a significant effect of nitrogen and a marginally significant effect of salt on principal component three, but no effect of treatment on the first two principal components. Nitrogen had a significant effect on particles/mL but treatment did not affect any of the other morphological traits individually. These results indicate that climate change has a complicated effect on freshwater microbial morphology at the community level. Future studies should focus on long-term changes in morphology in the field, focusing on the effects of nitrogen.
Media Consolidation's Relationship to Voter Turnout in Elections
(2022) Mazzetta, Marissa;
Media consolidation is on the rise especially when it comes to local news. This study aims to find if media consolidation affects citizens’ civic engagement, specifically voter turnout in non-presidential and presidential elections. Understanding what factors lead to higher voter turnout can be helpful in creating a more civically engaged country leading to progress that reflects the needs and wants of a more accurate majority. Consumption of local news has been tied to better civic engagement in the past. While media consolidation has been known to diminish the local news environment it has taken control over. Due to these two notions, it could be expected that there would be a connection between media consolidation and voter turnout. Through data analysis of voter turnout data of 24 Texas counties from the years 1990 to 2020 it was found through ANOVA tests that there were no significant changes in voter turnout between elections. These results lead to the belief that media consolidation alone does not have a significant impact on voter turnout. This opens up further understanding into the relationship between journalism and election turnout, and the reasons for fluctuation in voter turnout between elections.
Modelling Dynamics in the Macroeconomy Involving the Relationship between Economic Growth and Crime Rates
(2023) Mardanyan, Hayk;
The relationship between economic growth and crime rates is often the subject of statistical analyses by agencies such as the World Bank and the IMF. These agencies estimate a negative correlation between crime rates and economic growth: in environments of economic prosperity, crime tends to be lower. However, there are not many theoretical papers exploring why this has to be the case, or whether there are any underlying determinants of the growth and crime rates. One interesting paper modelling these variables is Goulas, A. and Zervoyianni, 2015: they incorporate crime rates into a standard Solow model and split public spending into productive spending and unproductive spending, where the latter stems from criminal behavior in the society. They then get a steady-state equation for aggregate output which is a function of crime rates, among others. This is one of many recent theoretical papers that try to incorporate crime rates into a general macroeconomic growth model. My project contributes to the ongoing academic discussion on the subject, featuring a statistical model where crime rates and economic growth are correlated and there is causality in both directions. This model will be used to estimate the causal effect of growth on crime rates and crime rates on growth, as well as to investigate the causal effect of institutions on both crime rates and growth. The paper also entertains the possibility of a “spiral effect”: as crime rates increase, there is a smaller fraction of the population involved in productive activities, which reduces economic growth. This in turn results in even more people resorting to criminal activities because there are less economic opportunities available as a result of economic slowdown. On the other hand, as crime rates decrease, economic growth will be enhanced, which will create even more economic opportunities and reduce crime rates even further. The statistical model is estimated by using a panel dataset involving post-colonial economies from both the advanced, developing and underdeveloped categories, spanning the years 2000 through 2019. I will use an instrumental variable approach to estimate the causal effect of growth on crime rates and crime rates on growth, as well as to test for the directionality of the causal effect of institutions on both crime rates and growth. The importance of this kind of research is evident: if the institutions of an economy play an important role in determining growth and crime rates in equilibrium, this may suggest that foreign assistance and institutional exchange programs aimed at improving institutions in poorer countries can go a long way in helping them get out of stagnant macroeconomic conditions such as meager economic growth and high crime.
Opinions on the Peruvian Executive: A Study on Presidential Transitions and Approval
(2023) Llerena, Gabriela;
This paper explores the various presidential transitions in Peru, their relationship with Congress and corruption, and the impact of Alberto Fujimori’s decade-long presidency. I build upon existing literature investigating Peruvian opinion and draw from nationally conducted Peruvian polls to investigate individual presidents' role in the public’s perceptions of corruption, support for democracy, tolerance of the president closing Congress, and confidence in elections, Congress, and the president. To supplement these public opinion surveys, I conducted qualitative interviews with Peruvians in the U.S. and Peru, providing a deeper look at what has impacted their opinion towards the government. I analyze how the rapid presidential turnover after 2016 influences public opinion and why the public looks more favorably upon the president than Congress. Since 2016, Peru has had six presidents, three of whom Congress impeached. Almost all Peruvian presidents have been involved in corrupt practices, yet the public views the president as more favorable than Congress. I find that Fujimori’s strong-handed presidency, differences in accountability of Congress and the president to the public, and heightened divisions between the two branches offer an explanation for public opinion. This study is important for exploring the ongoing presidential transitions and whether Peru hopes to regain governmental stability in the future.
Redshift Dependence of Stochastic Gravitational Wave Background and Galaxy Overdensity Cross-Correlation
(2023) Feist, Noelle;
Following [1], the cross-correlation between the stochastic gravitational wave background (SGWB) due to binary black hole mergers and the sky distribution of galaxies was computed. The SGWB anisotropies are obtained from the third observing run (O3) of Advanced LIGO, and the galaxy distribution was taken from the Sloan Digital Sky Survey (SDSS) spectroscopic catalogue. The angular power of the cross-correlation in 10Hz wide GW frequency bins and 0.1 wide redshift bins was found to be noise-dominated. The resulting angular cross-rcross-correlation power spectra were used to find the maximum likelihood estimates for parameters to a simplified astrophysical kernel with amplitude Amax and redshift center zc. No constraints were able to be placed on the redshift, but a 95% confidence upper-limit was found for Amax = 8.3 × 10−33erg/cm3s1/3. This analysis was limited by the redshift range of the catalogue and GW sensitivity. As data sensitivity grows, better estimates for the bound of the astrophysical kernel will be found.
Renewable Energy Development by Electric Cooperatives: Indirect Uses of Federal Energy Tax Credits
(2022-12-22) Gutenkauf, Gabriella;
In this thesis, I look to understand how electric cooperatives develop renewable energy in a cost-effective manner, despite the inability to use popular financing methods such as the production tax credit and the investment tax credit. I also analyze how their current practices may be impacted by the addition of direct pay as a policy tool in the Inflation Reduction Act. Electric cooperatives provide energy to 56% of the nation’s landmass, specifically to rural communities that investor-owned utilities do not reach. The national push for decarbonization of the energy industry has put requirements such as renewable portfolio standards on utilities, demanding certain percentages of their portfolio to come from renewable energy. Electric cooperatives struggle with this development of renewable energy because their status as not-for-profit entities prevents them from utilizing federal investment and production tax credits. I conducted four interviews with the electric cooperatives Dairyland Power, Great River Energy, Hoosier Energy, and Old Dominion Electric Cooperative to understand their decision-making process in the development of renewable energy. I identified five key factors impacting this decision making: providing low-cost energy to members, size of staff and resources, membership in the National Renewables Cooperative Organization, project size, and interconnection concerns. I also found that cooperatives had mixed opinions on whether they were hoping to quickly begin using direct pay options once it was available. These findings show that it will be very important that any future policy tool, including direct pay, will need to ensure it still allows cooperatives to achieve their goal of providing the lowest cost of energy.
Role of the cGAS-STING Signaling Pathway in 4-Hydroxynonenal-Induced Cellular Senescence
(2024) Fish, Shayla;
The cGAS-STING signaling pathway is responsible for recognizing cytosolic doublestranded DNA and initiating an inflammatory response as part of the innate immune system. This pathway has been correlated with the development of cellular senescence, a state of irreversible cell cycle arrest. Senescent cells accumulate with age and a senescent phenotype is associated with chronic inflammation and numerous age-related diseases. There is a lack of research connecting the cGAS-STING pathway to cellular senescence initiated by endogenous inducers of senescence. Using the endogenously produced reactive lipid aldehyde 4-Hydroxynonenal (4- HNE) to induce senescence, various small molecule inhibitors to components of the cGASSTING pathway were used to further examine this connection. Murine stromal vascular fraction cells and IMR90 cells, an immortalized human lung fibroblast cell line, were cultured and treated with 4-HNE in addition with two different small-molecule inhibitors of cGAS-STING pathway components. Using immunoblotting and quantitative real-time PCR techniques, protein and mRNA levels were analyzed to assess cGAS-STING pathway activation and the presence of a senescent phenotype with and without inhibitor presence. The results show upregulation of numerous protein and mRNA markers suggesting cGAS-STING pathway activation, as well as evidence of a senescent phenotype in cells treated with 4-HNE. However, both small molecule inhibitors showed inconsistent results in preventing a senescent phenotype. The results suggest the possibility of a mechanistic correlation between the cGAS-STING pathway and cellular senescence, however future work is required to further examine this relationship in the context of 4-HNE.
Survival Analysis of Associations Between Health Insurance Status, Race, Yearly Household Income and Diabetes Incidence
(2022) Bastian, Lauren;
Objective We examined the effects of health insurance status, race, and income, on diabetes incidence in a racially and socioeconomically diverse sample of middle-aged American women. Methods Using Kaplan-Meier survival curves and stratified Cox proportional hazards models, we evaluated the associations between insurance status, race, income, and diabetes incidence in a sample of 2,686 middle-aged women who participated in the Study of Women’s Health Across the Nation between the years of 1994 and 2008. Models were adjusted for covariates and stratified by age upon study entry. Results Women with lower incomes tend to have higher risk for incident diabetes after adjusting for health insurance status, race, household income, BMI, and age upon study entry. Black/African American and Hispanic women may be at especially high risk for incident diabetes after adjusting for other covariates. Uninsured women were at significantly higher risk for diabetes incidence after adjusting for race, BMI, and age upon study entry, but insurance status is not found to affect diabetes incidence after additionally adjusting for household income. Discussion Results for yearly household income and race reinforce findings from existing literature, and suggest the need for additional investigation of diabetes incidence among Hispanic women. Women without health insurance were at higher risk for diabetes when adjusted only for race, BMI, and age upon study entry. After adjusting the model additionally for household income, the association between insurance status and diabetes risk was non-significant, possibly due to confounding between household income and insurance status. Insurance status may be indicative of and confounded by several other socioeconomic, cultural, and environmental factors not explored in this study.
Urban Production of Fruits and Vegetables: Current Estimates and Opportunities for Growth in Ramsey County, Minnesota
(2023) Schulz, Laura;
Population growth and the progression of climate change will require a more sustainable, resilient, and equitable food system. A more sustainable food system may include shifting where food is grown, such as growing more perishable and intensive crops (fruits and vegetables) closer to large population centers. Production of fruits and vegetables near urban centers has the potential to offer a wide array of benefits, including increasing access to healthy food and reducing food waste. This project used USDA data to quantify the current production of fruits and vegetables in Ramsey County, Minnesota and estimate potential production capacity if fruits and vegetables were to be grown on farmland currently used to grow grains or raise animals, on land currently used for parking lots, and with rooftop gardens. These estimates were compared to the quantity required to meet the population of Ramsey County’s needs based on the Dietary Guidelines for Americans to illustrate potential pathways to meeting the nutritional needs of urban areas with an equitable, low-carbon food system. Current (2017) production of fruits and vegetables in Ramsey County meets its population’s needs for just under 4 days per year, while the potential production methods considered were estimated to add an additional 32.4 days of meeting the population’s needs. These low current and potential production figures emphasize the continued importance of rural areas as the primary producers of food for urban populations, while also illustrating the potential to significantly increase food production in urban areas and improve food system resiliency through diversifying where and how crops are grown.
When States Kill Their Own Citizens: Protest Repression Under Occupation in Kashmir
(2024) Rehman, Aleena;
The following study provides an analysis of the conditions under which a state chooses to repress protestors in the context of Indian-administered Kashmir. Three hypotheses were tested, all of which were informed by the theory that democratic states are more likely to repress their citizens when they are not seen as part of the central polity. I examined five different instances of protest in Kashmir, controlling for size and relative location, and for each I determined whether or not expressions of religion, ethnonationalism, or separatism were present in the protests, as well as the extent of repression or lack thereof. I then used statements made by government and security officials in order to analyze the impact of these three expressions on the extent of repression faced by the protestors. The case studies demonstrated that all three types of expressions are correlated with increased state repression, but separatism has the most support as a causal factor in increased protest repression. Government and security officials are inclined to justify repression against separatist protestors by citing the integrity and sovereignty of the state, while also placing an emphasis on the importance of Indian nationalism. Their statements also indicated a lack of tolerance for any expressions of nationalism that extend beyond Indian nationalism, while also deeming certain sentiments expressed in protests to be more acceptable than others.

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