Physical Sciences and Mathematics Commons^™

Selection-Based Convolution For Irregular Images And Graph Data, David Marvin Hart

Theses and Dissertations

The field of Computer Vision continues to be revolutionized by advances in Convolutional Neural Networks. These networks are well suited for the regular grid structure of image data. However, there are many irregular image types that do not fit within such a framework, such as multi-view images, spherical images, superpixel representations, and texture maps for 3D meshes. These kinds of representations usually have specially designed networks that only operate and train on that unique form of data, thus requiring large datasets for each data domain. This dissertation aims to bridge the gap between standard convolutional networks and specialized ones. It …

Artemisinin And Its Derivatives Reactions: Characterization Of The Reaction Products Using Lc/Tof Ms, Kogila Vijayan

Theses and Dissertations

Artemisinin (ART) is a sesquiterpene lactone and a popular malaria drug with potential anticancer properties. In this work, LC/TOF MS was used to investigate the reaction of ART with DNA bases and estradiol. ART-deoxyadenosine and ART-deoxycytidine interactions were studied in the presence of Fe (II) ions. ART-deoxyadenosine and ART-deoxycytidine reaction mixtures gave chromatographic signatures that remained unchanged at room temperature but grew after incubation at 37°C. The change in temperature from room temperature to 37°C was the main driver of adduct formation in these reactions. ART was found to react with Fe (II) ions as observed from several new chromatographic …

Algorithmic Fidelity And The Use Of Large Language Models In Social Science Research, Christopher Michael Rytting

Theses and Dissertations

In this dissertation, we argue that large language models (LLMs) exhibit a considerable amount of \textit{algorithmic fidelity}, a property where they have modeled ideas, behaviors, and attitudes of the population who generated their training data. This has important implications for social science, as this fidelity theoretically allows for the use of LLMs as effective proxies for human beings in experiments and research. We demonstrate this empirically in various social science domains (political partisanship, demographic surveying, voting behavior, hot-button policy issues, news media, populism, congressional summaries), in various applications (replicating social science survey findings, assisting in coding of text datasets, inferring …

Development Of New Chemical Probes To Delineate The Polyamine Regulation & Molecular Strategies To Unravel Protein Polyamination, Vennela Tulluri

Theses and Dissertations

Polyamines such as putrescine, spermidine, and spermine modulate critical cellular processes, including gene expression and cell proliferation. Cellular polyamine regulation is a complex mechanism controlled by three different proteins: Ornithine decarboxylase (ODC), Antizyme (OAZ), and Antizyme Inhibitor (AZIN). While ODC is directly involved in polyamine biosynthesis, OAZ, and AZIN regulate the ODC activity via protein-protein interactions. The dysregulation of ODC, OAZ, and AZIN leads to elevated polyamines in numerous pathologies, making them attractive targets for controlling polyamine levels. Besides regulating polyamine synthesis, OAZ modulates polyamine transport. However, the precise mechanism remains elusive. In this research, we discuss our approach to …

Halide Substitution Of Ternary Bismuth Chalcogenides For Photovoltaic Applications, Thomas Boggess

Theses and Dissertations

Semiconductors play an integral part in modern society. From computing to LEDs their use is ubiquitous, and no field is more reliant on them than that of power generation. Current political movements have seen a push to decrease reliance on traditional forms of power generation, which relies on fossil fuels, to renewable sources such as solar power. However, current commercial solar panels, based on silicon, are lacking in efficiency, only reaching between 18% and 22% efficiency.¹ In recent years, materials called perovskites have been garnering significant attention as possible replacements for silicon cells due to their favorable optoelectronic properties. …

Monolithic Multiphysics Simulation Of Hypersonic Aerothermoelasticity Using A Hybridized Discontinuous Galerkin Method, William Paul England

Theses and Dissertations

This work presents implementation of a hybridized discontinuous Galerkin (DG) method for robust simulation of the hypersonic aerothermoelastic multiphysics system. Simulation of hypersonic vehicles requires accurate resolution of complex multiphysics interactions including the effects of high-speed turbulent flow, extreme heating, and vehicle deformation due to considerable pressure loads and thermal stresses. However, the state-of-the-art procedures for hypersonic aerothermoelasticity are comprised of low-fidelity approaches and partitioned coupling schemes. These approaches preclude robust design and analysis of hypersonic vehicles for a number of reasons. First, low-fidelity approaches limit their application to simple geometries and lack the ability to capture small scale flow …

Beyond Algorithms: A User-Centered Evaluation Of A Feature Recommender System In Requirements Engineering, Oluwatobi Lasisi

Theses and Dissertations

Several studies have applied recommender technologies to support requirements engineering activities. As in other application areas of recommender systems (RS), many studies have focused on the algorithms’ prediction accuracy, while there have been limited discussions around users’ interactions with the systems. Since recommender systems are designed to aid users in information retrieval, they should be assessed not just as recommendation algorithms but also from the users’ perspective. In contrast to accuracy measures, user-related issues can only be effectively investigated via empirical studies involving real users. Furthermore, researchers are becoming increasingly aware that the effectiveness of the systems goes beyond recommendation …

Secure And Efficient Federated Learning, Xingyu Li

Theses and Dissertations

In the past 10 years, the growth of machine learning technology has been significant, largely due to the availability of large datasets for training. However, gathering a sufficient amount of data on a central server can be challenging. Additionally, with the rise of mobile networking and the large amounts of data generated by IoT devices, privacy and security issues have become a concern, resulting in government regulations such as GDPR, HIPAA, CCPA, and ADPPA. Under these circumstances, traditional centralized machine learning methods face a problem in that sensitive data must be kept locally for privacy reasons, making it difficult to …

Protecting The Vulnerable: Tornado Sheltering And Communication Of Public Shelters With A Case Study From The Covid-19 Pandemic, Craig Douglas Croskery

Theses and Dissertations

One of the greatest natural hazards that is faced with in much of the United States are tornadoes. Despite improvements in the warning processes, the risk of significant loss of life remains high. That is particularly true with vulnerable communities which have higher proportions of mobile homes; however, violent tornadoes are very difficult to manage in permanent homes or buildings as well. As a result, tornado shelters have been built in some communities and have become available to the public. However, their presence is intermittent, and there are many tornado-prone areas that lack such shelters.

After a public survey, it …

Verification Of The Localized Aviation Mos Program (Lamp) At Major Us Airports For Ifr Conditions, Mackenzie O'Rourke

Theses and Dissertations

The objective of this research is to quantify the LAMP’s performance when forecasting for IFR conditions at specific major airports for forecast hours one, three, six, and twelve, and further determine how the LAMP performs seasonally at those specific airports and forecast hours. Two by two contingency tables were used to calculate the Probability of Detection (POD), False Alarm Ratio (FAR), Critical Success Index (CSI), Heidke Skill Score (HSS), and Bias score. The results show that the LAMP performs relatively better in the cool season compared to the warm season consistently at each chosen airport, and that the LAMP performs …

Pairing And Rotation-Induced Nuclear Exotica In Covariant Density Functional Theory, Saja Teeti

Theses and Dissertations

Covariant density functional theory (CDFT) is one of the modern theoretical tools for describing the nuclear structure physics of finite nuclei. Its performance is defined by underlying covariant energy density functionals (CEDFs). In this dissertation and within the framework of the CDFT, different physical properties of the ground and the excited states of rotating and non-rotating nuclei have been investigated.

A systematic global investigation of pairing properties based on all available experimental data on pairing indicators has been performed for the first time in the framework of covariant density functional theory. It is based on separable pairing interaction of Ref.\ …

Eddy Current Defect Response Analysis Using Sum Of Gaussian Methods, James William Earnest

Theses and Dissertations

This dissertation is a study of methods to automatedly detect and produce approximations of eddy current differential coil defect signatures in terms of a summed collection of Gaussian functions (SoG). Datasets consisting of varying material, defect size, inspection frequency, and coil diameter were investigated. Dimensionally reduced representations of the defect responses were obtained utilizing common existing reduction methods and novel enhancements to them utilizing SoG Representations. Efficacy of the SoG enhanced representations were studied utilizing common Machine Learning (ML) interpretable classifier designs with the SoG representations indicating significant improvement of common analysis metrics.

Oxidation Resistance Of An Atomically Flat Cu(111) Surface: A First-Principles Study, Bipin Lamichhane

Theses and Dissertations

The first-principles calculation based on density functional theory (DFT) was used to study the oxidation resistance of atomically flat and atomic-step edges of Cu(111), diffusion of Cu atoms in different surfaces of alumina and interface properties of alumina and Cu(111), and magnetic properties of Mn-substituted strontium hexaferrite. The dissociation of oxygen molecules is the primary reason for the corrosion of metals, which deteriorates their application. Cu(111) flat surface, mono-atomic, and multi-atomic step edges were used to study oxygen diffusion. Penetration of oxygen on a Cu(111) flat surface requires high energy, indicating oxidation resistance. Our DFT result of oxygen diffusion into …

Pruning Ghsom To Create An Explainable Intrusion Detection System, Thomas Michael Kirby

Theses and Dissertations

Intrusion Detection Systems (IDS) that provide high detection rates but are black boxes lead
to models that make predictions a security analyst cannot understand. Self-Organizing Maps
(SOMs) have been used to predict intrusion to a network, while also explaining predictions through
visualization and identifying significant features. However, they have not been able to compete with
the detection rates of black box models. Growing Hierarchical Self-Organizing Maps (GHSOMs)
have been used to obtain high detection rates on the NSL-KDD and CIC-IDS-2017 network traffic
datasets, but they neglect creating explanations or visualizations, which results in another black
box model.
This paper offers …

Tornado Outbreak False Alarm Probabilistic Forecasts With Machine Learning, Kirsten Reed Snodgrass

Theses and Dissertations

Tornadic outbreaks occur annually, causing fatalities and millions of dollars in damage. By improving forecasts, the public can be better equipped to act prior to an event. False alarms (FAs) can hinder the public’s ability (or willingness) to act. As such, a probabilistic FA forecasting scheme would be beneficial to improving public response to outbreaks.

Here, a machine learning approach is employed to predict FA likelihood from Storm Prediction Center (SPC) tornado outbreak forecasts. A database of hit and FA outbreak forecasts spanning 2010 – 2020 was developed using historical SPC convective outlooks and the SPC Storm Reports database. Weather …

Analysis Of Weather-Related Flight Delays At 13 United States Airports From 2004-2019 Using A Time Series And Support Vector Regression, Caroline E. Sleeper

Theses and Dissertations

This study seeks to investigate weather-related flight delay trends at 13 United States airports. Flight delay data were collected from 2004-2019 and normalized by airport operations data. Using Support Vector Regression (SVR), visual trends were identified. Further analysis was conducted by comparing all four meteorological seasons through computing 95% bootstrap confidence intervals on their means. Finally, precipitation and snowfall data were correlated with normalized delays to investigate how they are related. This study found that the season with the highest normalized delay values is heavily dependent upon location. Most airports saw a decrease in the SVR line at some point …

The Influence Of Marsh Edge And Seagrass Habitat On Summer Fish And Macroinvertebrate Recruitment To A Northern Gulf Of Mexico Coastal System, Rebecca Lea Gilpin

Theses and Dissertations

Marshes and seagrass beds have been widely recognized as important habitat for estuarine species, but less has been done on how these habitats interact and function together, thereby limiting understanding of the variability of juvenile recruitment to coastal systems. Therefore, the objective of this study was to assess the interaction between fringing marsh and adjacent seagrass for the provision of habitat for juvenile nekton. Weekly seine net and benthic seagrass core sampling from June to November 2020 determine the relationship between nekton and marsh-edge and seagrass habitat. This study shows disparate results, in terms of the effects of proximity to …

Determining The Impact Of Post-Harvest Water Management On Chironomid Abundance, Agrochemical Biomass And Potential Trophic Biomagnification, Mason Thomas

Theses and Dissertations

Agriculture has diminished shorebirds’ natural habitat in the Mississippi Alluvial Valley. Remaining natural stopover sites are supplemented with agricultural fields during the fall and winter. This study evaluates the impact of 4 different post-harvest water management strategies on shorebird food abundance and potential agrochemical biomagnification. Chironomid samples estimated abundance, biomass, and chironomid agrochemical concentration in each field. A risk assessment of agrochemical biomagnification to shorebirds was made across all treatments. Of treatments represented on all study sites, winter treatment had greatest chironomid abundance and biomass. Models indicated that days since flood initiation, start date, and temperature are significant predictors of …

Variational And Adaptive Non-Local Image Denoising Using Edge Detection And K − Means Clustering, Shiraz Mujahid

Theses and Dissertations

With the increased presence of image-based data in modern applications, the need for robust methods of image denoising grows greater. The work presented herein considers two of the most ubiquitous approaches towards image denoising: variational and non-local methods. The effectiveness of these methods is assessed using quantitatively using peak signal-to-noise ratio and structural similarity index measure metrics. This study employs ��−means clustering, an unsupervised machine learning algorithm, to isolate the most dominant cluster centroids within the incoming data and propose the introduction of a new adaptive parameter into the non-local means framework. Motivated by the fact that a majority of …

Quantifying Seasonal And Annual Precipitation Variability On San Salvador Island, Bahamas Using Surface Observations And Satellite Estimates., John Bryson Wells

Theses and Dissertations

San Salvador Island is a small Bahamian island located in the subtropics just north of the Tropic of Cancer. Due to its subtropical location, the island is influenced by both mid-latitude and tropical weather patterns. These weather patterns vary in scale from localized convective uplift to synoptic-scale systems. This study compares satellite-derived estimates of precipitation and rain gauge observations from June 2019 through September 2021 to evaluate the relationship between the two datasets. This study then uses the satellite-derived estimates of precipitation over a 20-year period to quantify annual and seasonal variability in precipitation on San Salvador. Corroborating past research, …

Evaluating The Relationship Between Methane Seeps And Seafloor Geomorphology On The Northern Us Atlantic Margin, Gabriel Hernandez

Theses and Dissertations

Methane seeps are a transport pathway for carbon from seafloor sediments to the marine environment with important implications for global biogeochemical cycling. Accordingly, there is substantial interest in better understanding the processes that control seep location and predicting the distribution of seeps with existing seafloor datasets. Visual evaluation of methane seeps, in multibeam sonar water column data, suggests a spatial relationship between seeps and specific seafloor morphologic features such as ridge crests. In this thesis, seafloor geomorphology at 1996 seep detection sites on the US Atlantic margin was quantitatively characterized by geomorphologic phonotype, bathymetric position index, slope, rugosity, and aspect …

Automated Mapping Of Oblique Imagery Collected With Unmanned Vehicles In Coastal And Marine Environments, Jacob B. Freeman

Theses and Dissertations

Recent technological advances in unmanned observational platforms, including remotely operated vehicles (ROVs) and small unmanned aerial systems (sUAS), have made them highly effective tools for research and monitoring within marine and coastal environments. One of the primary types of data collected by these systems is video imagery, which is often captured at an angle oblique to the Earth’s surface, rather than normal to it (e.g., downward looking). This thesis presents a newly developed suite of tools designed to digitally map oblique imagery data collected with ROV and sUAS in coastal and marine environments and quantitatively evaluates the accuracy of the …

Developing Genotypic And Phenotypic Systems For Early Analysis Of Drug-Resistant Bacteria, Yesman Akuoko

Theses and Dissertations

Antimicrobial resistance in bacteria is a global health challenge with a projected fallout of 10 million deaths annually and cumulative costs of over 1 trillion dollars by 2050. The currently available tools exploited in the detection of bacteria or their DNA can be expensive, time inefficient, or lack multiplex capabilities among others. The research work highlighted in this dissertation advances techniques employed in the phenotypic or genotypic detection of bacteria and their DNA. In this dissertation, I present polymethyl methacrylate-pressure sensitive adhesive microfluidic platforms developed using a time-efficient, inexpensive fabrication technique. Microfluidic devices were then equipped with functionalized monoliths and …

Utilizing Machine Learning Techniques To Predict Credit Card Payment Defaults, Madison Guerra

Theses and Dissertations

The question of accurately predicting credit card defaulters has been explored in numerous studies in the past. In these studies, the researchers utilized various machine learning theories and techniques to make the determination the extent of defaults. Unfortunately, some constraints were encountered, and the limitations that existed from the previous works have been discussed. This project attempted to address these issues with special attention given to more recently available data. Specifically, in this project, we looked at data provided by one Kaggle user, which utilized the data from the American Express credit card competition, which ranges from late March 2018 …

Explorations In Baseball Analytics: Simulations, Predictions, And Evaluations For Games And Players, Katelyn Mongerson

Theses and Dissertations

From statistics being reported in newspapers in the 1840s, to present day, baseballhas always been one of the most data-driven sports. We make use of the endless publicly available baseball data to build models in R and Python that answer various baseball- related questions regarding predicting and optimizing run production, evaluating player effectiveness, and forecasting the postseason. To predict and optimize run production, we present three models. The first builds a common tool in baseball analysis called a Run Expectancy Matrix which is used to give a value (in terms of runs) to various in-game decisions. The second uses the …

Testing The Use Of Anisotropy Of Magnetic Susceptibility (Ams) In Determining Genetic Origins Of Paleoproterozoic Diamictites, Miles A. Harbury

Theses and Dissertations

The Huronian Supergroup (2.4-2.1 Ga) in Ontario, Canada is widely accepted as an important stratigraphic interval for interpreting Paleoproterozoic climate. This is because it contains some of the oldest glaciogenic rocks on the planet. However, massive and poorly-stratified diamictites in the Gowganda Formation of the Huronian Supergroup have varying depositional interpretations among sedimentologists (subglacial, rainout, sediment gravity flow etc.). Diamictites can occur from a variety of processes and, therefore, proper depositional interpretation is essential for unraveling detailed environmental conditions at the time of deposition. Anisotropy of magnetic susceptibility (AMS) looks at the orientation of magnetic particles within a rock and …

The Role Of Energy Storage In The Transition Toward A Carbon-Neutral Economy, Siyu Feng

Theses and Dissertations

Energy transitions to less-carbon intense technologies, such as wind and solar energy, in the electricity, sector are crucial to realizing international climate goals because the electricity sector has been one of the main global carbon emitter for decades, and environmental plans in most countries involve electrifying heavily polluting industries with clean electricity generation. The intermittency problem of renewable energy has been the main stumbling block on the path, and energy storage is now referred to as the key in these transitions because it can boost renewable energy use while also improving the efficiency of conventional power plants (Hall and Bain, …

Applying The Efficiency Gap To Wisconsin Politics, Joseph Robert Szydlik

Theses and Dissertations

Gerrymandering is a plague on modern democracy, blatantly violating the democratic principle of “one person, one vote.” Here we will methodically examine the 2018 Wisconsin state assembly election, and using a metric known as the efficiency gap demonstrate the extent to which gerrymandering played a role. Through this metric, and a probabilistic simulation of our own, we will show that in this election the Republican party benefited from systematic partisan gerrymandering. Additionally, we will use these findings to suggest methods for correcting this undemocratic practice that both parties utilize in order to disenfranchise opposition voters.

Change Point Detection For A Process Having Several Regimes, Oliver Gerd Meister

Theses and Dissertations

In this dissertation, possible methods for multiple change point detection on Markovchain processes are studied. Related works for oine and online change point detection are discussed and their applicability on sequential multiple change point detection for several regimes is evaluated. We develop a method for a multiple change point detection for a process having three regimes. Its eciency is then evaluated on simulated Markov chain data by looking into dierent scenarios such as processes that signicantly dier between each other or probability distributions that are slightly similar. This approach is then applied on Covid- 19 hospital data. Therefore, the data …

Concurrency Controls In Event-Driven Programs, Yonglun Li

Theses and Dissertations

Functional reactive programming (FRP) is a programming paradigm that utilizes the concepts of functional programming and time-varying data types to create event-driven applications. In this paradigm, data types in which values can change over time are primitives and can be applied to functions. These values are composable and can be combined with functions to create values that react to changes in values from multiple sources. Events can be modeled as values that change in discrete time steps. Computation can be encoded as values that produce events, with combination operators, it enables us to write concurrent event-driven programs by combining the …