Digital Commons Network^™

Stochastic Universal Differential Equations For Epidemiological Modeling: Uncertainty Quantification In Disease Transmission Dynamics, Alice Menaya Armah-Bonney

Electronic Theses and Dissertations

Epidemic forecasting requires not only predictions of expected case counts, but also quantification of uncertainty, although existing surrogate modeling frameworks for agent-based models remain fundamentally deterministic. In this thesis a Stochastic Universal Differential Equation framework is presented that extends the deterministic Universal Differential Equation approach by incorporating a learnable stochastic diffusion term, enabling calibrated probabilistic forecasts while preserving the mechanistic interpretability and computational efficiency of the deterministic baseline. In doing so, a two-phase training algorithm is introduced to ensure stable convergence and the framework is validated against the ensemble output from ExaEpi, an exascale agent-based model of a COVID-19 outbreak …

On The Algebraicity Of The Tic-Tac-Toe Matroid And Homogeneous Mixed Bowtie Systems, Benjamin R. Allen

Electronic Theses and Dissertations

This thesis is presented in two parts. First, we explore whether the class of algebraic matroids is closed under duality, a decades-old open question. We consider the Tic-Tac-Toe matroid as a potential candidate to answer the open question. The Tic-Tac-Toe matroid is known to satisfy many of the necessary conditions for a matroid to be algebraic and has a non-algebraic dual.  Second, we focus on decompositions of the complete mixed graph into mixed bowties. A complete mixed graph has between every pair of vertices an undirected edge and antiparallel arcs. A mixed bowtie is a graph consisting of two 3-cycles …

Academic And Demographic Predictors Of Retention And Persistence In Business Programs: Post-Covid Cohorts Of Traditional And Ncccs Transfer Students, Matthew K. Crump

Electronic Theses and Dissertations

This quantitative study examined academic and demographic predictors of first-year retention and major persistence among traditional first-year and North Carolina community college transfer students enrolled in undergraduate business programs. Guided by Tinto’s 1993 Model of Student Retention and Astin’s 1984 Theory of Student Involvement, the research focused on students who entered two AACSB-accredited institutions within the UNC System during Fall 2021, Fall 2022, and Fall 2023 as traditional first-year students or as transfer students from North Carolina community colleges.

Institutional data from the Banner Student Information System provided the basis for logistic regression analyses that examined predictors including high school …

Durable, Distributed Llm Inference On Cots Devices, Brycen E. Dunn

Electronic Theses and Dissertations

The advancement of Large Language Models (LLMs) has fundamentally changed the nature of natural language processing. The substantial memory requirements of frontier models creates a significant barrier to entry, centralizing inference. This thesis presents the design and implementation of a distributed inference framework designed to democratize LLMs by leveraging commodity devices. The framework combines the resources of heterogeneous COTS devices into a unified compute pool, enabling the inference of models exceeding a single device's memory capacity. A novel Task Partitioning Engine (TPE) analyzes model architectures, profiles node capabilities, and supports pipeline and expert parallelism strategies. The primary contribution is a …

Stability Of Paraffin-Insulated Nitrogen-Doped Carbon Fiber Ultramicroelectrodes, Maxwell H. Kwakwah

Electronic Theses and Dissertations

Nitrogen-doped carbon materials can facilitate the reduction oxygen-oxygen bonds, a key step in electroreduction of both O₂ (an important reaction in energy applications) and H₂O₂ (an important reaction in sensing and biosensing). Our lab previously demonstrated that thermal decomposition of urea in the presence of carbon fiber (CF) results in an N-doped carbon material that exhibits good electrocatalytic properties for H₂O₂ reduction. However, previous methods of insulating single N-doped CF via laser heating of borosilicate capillaries and epoxy to prepare ultramicroelectrodes (UMEs) seemed to adversely affect surface nitrogen contents and electrocatalytic properties. More recent work that utilized paraffin to …

Post-Vote Tampering In Nigerian Elections And The Role Of Blockchain-Enabled Electoral Systems, Ransome Chukwubuikem Enechukwu

Electronic Theses and Dissertations

Post-vote tampering during the collation and transmission of election results remains a persistent challenge in Nigerian elections, enabling manipulation of already-cast votes and weakening public trust in electoral outcomes. Existing technological interventions, including biometric voter accreditation and digital result transmission systems, improve voter authentication but do not adequately secure the post-vote result collation process. This thesis proposes a blockchain-enabled framework designed to protect the integrity of election results during the collation and transmission stages. Using a Design Science Research methodology, the study develops a permissioned blockchain framework based on Hyperledger Fabric that records polling-unit results as immutable ledger entries and …

Addressing Substance Use Disorder In Rural Appalachia: Improving Access And Treatment Outcomes For Justice-Involved Individuals, Jessica Muldowney

Electronic Theses and Dissertations

Background: Opioid use disorder (OUD) represents a critical public health crisis disproportionately affecting justice-involved (JI) populations, with approximately 65% of incarcerated individuals having substance use disorders (James & Beatty, 2006). Rural Appalachian communities face compounded challenges due to limited healthcare access, provider shortages, and cultural stigma surrounding addiction treatment. Despite evidence demonstrating that medication-assisted treatment (MAT) reduces recidivism and overdose deaths, only 20% of correctional facilities offer these services (Klein & Seppala, 2019).

Objective: This mixed-methods study evaluated organizational readiness and infrastructure capacity for implementing evidence-based OUD interventions, specifically MAT programs across three rural counties in northwestern North Carolina.

Methods: …

Psychometric Properties Of The Interpersonal Style Questionnaire (Isq) And The Patterns Of Thinking Survey (Pots), Genevieve Allison

Electronic Theses and Dissertations

Self-regulation is a complex concept that includes multiple interacting factors, and it is studied across multiple fields of psychological research. Various theoretical models have been offered to explain this concept. Although models differ in their definitions of self-regulation, all consistently posit that it consists of emotional, behavioral, interpersonal, and cognitive domains. The current study examined the psychometric properties of two novel measures – 1) McVay and Stinson Interpersonal Style Questionnaire (ISQ) and 2) Stinson and McVay Patterns of Thinking Survey (POTS) – utilizing both a clinical and nonclinical sample. Results indicate that these measures are comprised of three factors across …

Estimating Body Size And Biogeography In The Genus Alligator, Madelyn M. Turala

Electronic Theses and Dissertations

Several studies have examined correlations between total body length (TL) and skeletal measurements in the American alligator (Alligator mississippiensis), with some measurements serving as stronger predictors of TL than others. Femur length (FL) has been found to be tightly correlated with TL in A. mississippiensis, and this relationship has been used to estimate body size of extinct crocodilians. This thesis demonstrates that the humerus, radius, ulna, and tibia are also strongly correlated with TL and useful for body size estimation in A. mississippiensis, and thus, can be applied to related extinct crocodilians. Additionally, species distribution modeling …

A Machine Learning Framework For Early-Stage Cost Estimation Of Transportation Projects, Pritom Paul

Electronic Theses and Dissertations

To address the limitations of traditional planning-level cost estimating methods, such as reliance on statewide averages, heavy reliance on engineering judgment, and high levels of inaccuracy, this study developed two data-driven frameworks and corresponding tools. The first framework focused on resurfacing projects and used treatment-specific simple linear regression based on lane miles and geographic location. The second addressed a broader group of construction projects and used multiple linear regression with project length, route type, and right-of-way cost as key predictors. In both frameworks, the final estimates are computed by aggregating multiple estimates produced by county-, region-, and state-level models. The …

Adsorption Of Pfas On Bridged Functionalized Organosilica Materials, Elisha Lawerh Kabutey

Electronic Theses and Dissertations

PFAS are hazardous contaminants that have a devastating impact on human health and the environment. Their hazardous nature has led to the development of various adsorption methods for removing these contaminants from water sources. In this study, functionalized organosilica materials were synthesized from bis[3-(trimethoxysilyl)propyl] amine using the sol-gel method. The surface amino groups of the organosilica were converted into amine hydrochloride groups. Their adsorption properties were evaluated using salts of perfluorooctanoic acid, perfluorooctanesulfonic acid, and perfluorobutanesulfonic acid. Results showed excellent adsorption capacity of the materials. Adsorption of PFAS leads to particle agglomeration and flotation of the spent material. A column …

The Influence Of Intervention Strategies On Students With Disabilities Who Exhibit Challenging Behaviors In Rural Public Schools: Teacher Perceptions, Ben B. Robertson

Electronic Theses and Dissertations

This phenomenological qualitative study addressed rural teachers' perceptions of the influence of intervention strategies on students with disabilities who exhibit challenging behaviors. The purpose of this study was to examine teachers’ perceptions of the effect of intervention strategies on academic achievement, student behavior outcomes, and teacher self-efficacy through the lens of Bandura’s Social Cognitive Theory. This theory is a complex, dynamic interaction among people, their behaviors, and their environments. Data collection included 14 individual interviews, conducted on Zoom with educators from one school district in Southern Virginia, including seven general education teachers and seven special education teachers. Data analysis strategies …

“The Distance And Time Difference Aren’T Helping”: Family Communication Practices Of African Graduate Students Adapting To A New Country, Hummuh Abubakar

Electronic Theses and Dissertations

This qualitative study examined how international graduate students maintained long-distance communication with family members while adapting to life in the United States. Drawing on semi-structured interviews with seven international students, the research explored how participants sustained emotional closeness, manage disclosure, and select communication media across geographic distance. Guided by Communication Privacy Management Theory and Media Richness Theory, the study analyzed how students regulated private information and strategically used video calls, voice calls, and messaging platforms to meet relational and emotional needs. Findings revealed four primary themes: reliance on digital communication technologies; the emotional and psychological functions of family communication; structural …

Resource Allocation Trade-Offs Between Longevity And Reproduction In Daphnia Magna, Amelia Pearson

Electronic Theses and Dissertations

Although trade-offs between longevity and reproduction have been described for a long time, the genetic mechanisms by which organisms modulate allocation of resources between these two essential processes remain poorly understood, due to their complex nature and their modification by existing nutritional states and environmental cues. Daphnia magna represents a valuable model for investigation in this area due to their moderate lifespan and cyclic parthenogenetic mode of reproduction, allowing for the easy study of gene by environment interactions. This dissertation first investigates the change in mortality, reproduction, activity, and gene expression when fully fed Daphnia and calorically restricted Daphnia are …

Perceptions Of Rural School Resource Officers On Training, Roles, And Interactions With Students In Special Populations, Mary Jane M. Allen

Electronic Theses and Dissertations

This qualitative inductive study was conducted with rural school districts located in the Middle Grand Division of Tennessee. School Resource Officers' (SROs) and K–12 school administrators’ perceptions of their roles were assessed. Perceptions of school policing from both samples were assessed regarding SRO training, roles, and expectations for working with school law enforcement officials. This also included respondents' views on how students with disabilities are treated. The research conducted in rural Middle Tennessee counties examined SROs’ and K–12 administrators’ perceptions through data collected from in-depth open-ended interviews and a pre-written analysis. The proliferation of police officers assigned to schools beginning …

Media Portrayal Of High-Profile Female Victims Of Sexual Harassment, Chinenye Nwaneri

Electronic Theses and Dissertations

This rhetorical study investigated how the Nigerian media portray high-profile female victims of sexual harassment. The research was undertaken in response to concerns that media narratives often reinforce gender stereotypes and influence public perceptions of victims. Focusing on the sexual harassment allegations made by senator Natasha Akpoti-Uduaghan against Senate president Godswill Akpabio, the study analyzed newspaper coverage from Daily Trust and Vanguard between February and December 2025. Using Critical Discourse Analysis within the framework of Feminist Media Theory, the research examined how language and framing shaped the representation of the female accuser. The findings reveal that media coverage constructed the …

Parent Engagement And Advocacy In Individualized Education Programs In Rural Appalachian School Districts, Mollie Rutledge

Electronic Theses and Dissertations

The purpose of this phenomenological study was to explore parent engagement and parent advocacy in the Individualized Education Program (IEP) development and implementation in rural Appalachian school districts. Parent engagement and parent advocacy in Individualized Education Program (IEP) development and implementation are persistent challenges in special education. By intentionally grounding this research in rural Appalachia, the researcher responded to calls for education research that is attentive to the complexity and diversity of rural communities. Parents in rural areas face unique challenges related to poverty, isolation, and limited resources that can influence their engagement and advocacy in the IEP process. The …

Extremum Seeking Compensation And Quantification Of Position Sensor Offset Error In Speed-Controlled Permanent Magnet Synchronous Motors, Tessa Biondo

Masters Theses

Position sensor offset errors present a persistent challenge in speed-controlled permanent magnet synchronous motor drives operating under field-oriented control. Even small, constant offsets in the measured rotor position can reduce torque effectiveness, requiring increased current and voltage demand to maintain the commanded speed and resulting in degraded speed regulation performance across a range of operating conditions. These effects are particularly problematic in speed-controlled systems, where speed loop dynamics cause increased electrical effort and limit overall performance. Many existing detection and compensation approaches are either dependent on the system model, require offline calibration, or are primarily designed for torque-controlled operation. This …

Distribution Mapping And Modeling Of The Invasive Japanese Knotweed, Jossalyn Rogalski

Masters Theses

This thesis investigates the distribution of invasive Japanese knotweed across Michigan. This plant poses significant challenges to land management due to its rapid growth, environmental impacts, and difficulty of removal once established. Using geographic information systems (GIS), remotely sensed data, and secondary environmental datasets, this research maps current infestations and analyzes key factors influencing the species’ growth and dispersal, such as soil composition, hydrology, land use, and a range of environmental variables, including climatic (annual mean temperature, temperature seasonality, annual precipitation, precipitation seasonality), elevation, vegetation and hydrological indices (NDVI, EVI, NDWI), percent tree cover, and distance to roads. Spatial analysis …

Transformer Vulnerability To Geomagnetically Induced Currents Using Layered Soil Conductivity Models, Junior A. Sterling

Masters Theses

Geomagnetically induced currents (GICs) pose a significant threat to modern power transformers connected to long high-voltage transmission systems, particularly in regions with low subsurface electrical conductivity. During geomagnetic disturbances (GMDs), time-varying magnetic fields induce surface electric fields that drive quasi-DC currents through grounded transformer neutrals. These currents can bias transformer cores, leading to saturation, waveform distortion, and potential system instability. Despite extensive research, the role of regional Earth conductivity in shaping electric fields and transformer response remains an area requiring deeper investigation.

This study analyzes how contrasting Earth conductivity profiles influence GIC magnitude and transformer saturation risk using two representative …

Transient Mitigation In Dual Active Bridge Converter Using An Auxiliary Converter With High-Frequency Selective Control For Load Step-Down Condition, Sachith Dilshan Wijesooriya

Masters Theses

Dual Active Bridge (DAB) converters are widely utilized in applications such as electric vehicles, renewable energy systems, and solid-state transformers due to their high efficiency, galvanic isolation, and bidirectional power transfer capability. However, during rapid load transitions, DAB converters frequently exhibit significant output voltage overshoot and prolonged settling times, which increase device stress and adversely affect system reliability. This thesis proposes an auxiliary-circuit-based transient mitigation method to address these limitations. The auxiliary circuit, implemented as a bidirectional Buck–Boost stage, operates in Boost mode during load step-down events to absorb excess energy and suppress the resulting voltage overshoot. The design of …

Haunted By A Cheap Ghost: Objects As Identity, Caitlin Zachow

Masters Theses

I am haunted by a cheap ghost, surrounded by inherited memories that are not my own, preserved in heirlooms that leave little room for me to create souvenirs of my own experience. In response, my practice centers on the personal significance of collections as outward expressions of identity, personality, and lived experience. Rooted in themes of Midwestern Americana, this exhibition presents narrative tableaus and curated collections that examine how personal identity is constructed through objects of memory, and display.

Informed by research into the history of kitsch, Sigmund Freud’s concept of the uncanny, and the “outmoded,” my work considers how …

Isolation, Purification, And Characterization Of Α-Galactosidase From Watermelon (Citrullus Lanatus), Christopher Henley Jr.

Chemistry & Biochemistry Undergraduate Honors Theses

The enzyme α-galactosidase is a type of glycosidase that removes galactose sugar units from larger molecules in cells. Compounds that inhibit glycosidases have been useful for understanding the structure and function of the enzymes they inhibit, and some have been used to treat certain diseases. Using inhibitors of α-galactosidase to study its characteristics and mechanisms may provide insights into its role in disease and its general utility. Advances in fields such as agriculture, sustainable fuels, and biomedicine may be facilitated by inhibition studies of α-galactosidase, but the current library of known inhibitors is relatively lacking. Obtaining α-galactosidase enzymes from chemical …

Tunable Physical Color In Nanostructured Materials: Exploring Reversible Mechanisms For Active Optical Control, Matt Hughes

Chemistry & Biochemistry Undergraduate Honors Theses

Vanadium Dioxide (VO₂) thin films have been grown on silicon wafers using atomic layer deposition of TDMAV (tetrakis(dimethylamino)vanadium(IV)) and H₂O as precursors. A quartz crystal microbalance (QCM) measurement was used during deposition to confirm growth and resulted in a growth rate of approximately 0.6 Angstroms/cycle. X-Ray Reflectivity (XRR) was performed to confirm growth thickness and reported an approximately 30 nm thin film after 500 cycles of TDMAV precursor deposition. X-Ray photoelectron spectroscopy was utilized to determine the phase of the vanadium samples and confirmed the presence of vanadium dioxide as prepared and after annealing under nitrogen …

Constraint-Aware Metaheuristic Optimization For Experimental Design, Benjamin N. Fuller

All Graduate Theses and Dissertations, Fall 2023 to Present

Designing experiments becomes much more challenging when many variables and strict constraints are involved, as is common in modern science and engineering. This thesis introduces a new computational and mathematical framework that efficiently searches for optimal experiments in complex, high-dimensional spaces where traditional methods fail. By combining geometric techniques with flexible optimization algorithms like particle swarm optimization, our methods handle difficult constraints while scaling to real-world problems. Built in the high-performance Julia programming language and released as open-source software, this work bridges advanced theory with practical tools, offering researchers a powerful and accessible way to design better experiments under realistic …

Effects Of Tourist Feeding On The Gut Microbiome And Ecophysiology Of Endangered Northern Bahamian Rock Iguana (Cyclura Cychlura), Erin Lucy Lewis

All Graduate Theses and Dissertations, Fall 2023 to Present

The lifespan and reproduction of an animal depends on maintaining a healthy physiology. The proportion of individuals that survive to an age at which procreation can occur is important to long-term stability of populations and contributes to species survival. Health in an animal is measured in a variety of ways, including through monitoring of the body’s physiological systems, as well as its ability to respond to invading pathogens, and through the different types of bacteria present in the gut. Relationships among those different health metrics have been discovered in recent years and have been found to play important roles in …

A Low Power Fpga Compute Array For Machine Learning And Artificial Intelligence Applications, Todd Wilson

All Graduate Theses and Dissertations, Fall 2023 to Present

Modern small satellites often lack the ability to analyze their data in real time, relying instead on downlinking raw measurements to Earth before any scientific interpretation can occur. This delay restricts missions that require rapid awareness of environmental or space-weather events. This thesis presents the Low-power Array for Cubesat Edge Computing Architecture, Algorithms, and Applications (LACE-C3A), a hardware platform designed to enable in-orbit data processing within the power and volume limits of CubeSat-class spacecraft. 

LACE-C3A uses a modular cluster of flash-based FPGAs, which offer low power consumption, radiation resilience, and in-flight reconfigurability. The system consists of a Controller board responsible …

Aerodynamic Parameter Estimation For A Scaled F-16: A Simulation-Based Sensitivity Analysis, Kathle C. Tischner

All Graduate Theses and Dissertations, Fall 2023 to Present

The physical motion of an aircraft is determined by the resulting forces and moments acting on the aircraft. These forces and moments can be defined as a mathematical equation where the control deflections, rotation rates, and orientation of the aircraft are multiplied by individual constants and summed together to define the entire force or moment. This method results in a highly accurate model that defines the motion of the aircraft at low angles of attack and sideslip. Initial calculations of the aerodynamic model are created based on analytical estimations based on the physical properties of the aircraft. Additional refinement of …

Online Act Guide For Sub-Clinical And Clinical Insomnia Among College Students, Guadalupe "Gabe" San Miguel

All Graduate Theses and Dissertations, Fall 2023 to Present

College students are shown to have more sleep difficulties, specifically insomnia. These sleep difficulties compared to the general public due to the college environment (for example increase screen time, sedentary time, or alcohol use). Students with reported sleep difficulties have ties to lower GPA and lower odds of graduation. That is why this dissertation conducted a comparison between an online version of Acceptance and Commitment Therapy (intervention) to a placebo condition among college students with insomnia to help determine if the intervention had better outcomes over time. Each condition (intervention = 39; placebo = 40) completed questionnaires at the start …

Parental Socialization Practices As Protective Factors Of Lgbtq+ Youth Well-Being And Sexual Health, Melissa M. Ferguson

All Graduate Theses and Dissertations, Fall 2023 to Present

LGBTQ+ teens face challenges like discrimination and exclusion from school-based sex education. Support from parents is crucial for helping LGBTQ+ teens feel safe and confident. Most research has only looked at how parents react when their child comes out, and less about how parents support their child in everyday life. This two-study dissertation explored how parents help support and protect their LGBTQ+ teens’ well-being over time.

The first study looked for patterns of protective parenting across interviews with LGBTQ+ teens and their parents from diverse racial and ethnic backgrounds. Teens and parents shared their experiences of open communication, building community, …