Digital Commons Network^™

A Neuro-Symbolic Ai Approach To Scene Understanding In Autonomous Systems, Ruwan Tharanga Wickramarachchige Don

Theses and Dissertations

Effectively understanding scenes requires a unified representation of scene data and background knowledge. A neuro-symbolic AI approach to scene understanding leverages such a unified representation to enable advanced expression, inference, and labeling of scenes, improving the perception of autonomous systems.

Scene understanding remains a central challenge in the machine perception of autonomous systems. It requires the integration of multiple sources of information, background knowledge, and heterogeneous sensor data to perceive, interpret, and reason about both physical and semantic aspects of dynamic environments. Current approaches to scene understanding primarily rely on computer vision and deep learning models that operate directly on …

An Efficient Detection And Deep Clustering Based Pipeline For Reliable Rodent Ultrasonic Vocalization Analysis, Sabah S. Anis

Theses and Dissertations

Ultrasonic vocalizations (USVs) are critical for understanding rodents' emotional states and social behaviors. However, manual analysis of USVs is time-consuming, subjective, and prone to errors. This thesis presents an automated pipeline that addresses these challenges by performing efficient USV detection and clustering. The proposed approach significantly reduces the time and effort needed to analyze USV data while improving accuracy and reproducibility.

To address this gap, we introduce ContourUSV, a five-step pipeline for USV detection. First, it begins with generating spectrograms from audio recordings, which are then pre-processed to enhance the contrast between USVs and background noise. Key steps include median …

Post-Selection Inference In Regression Models, Qinyan Shen

Theses and Dissertations

This dissertation develops new methodology for valid statistical inference following model selection in various regression settings. We first consider the logistic regression model for a binary response that can only be observed at the group level, as in group testing, and is subject to testing error. With the true responses only partially observed, we employ the expectation-maximization (EM) algorithm to account for missing information in the response data and simultaneously conduct variable selection using the LASSO-penalized log-likelihood function. After variable selection, we extend an existing post-selection inference method based on the polyhedral lemma \parencite{lee2016exact} to make inferences on selected covariates, …

Methods And Applications For Bayesian Semiparametric Survival Analysis, Zile Zhao

Theses and Dissertations

Survival analysis is a cornerstone of biomedical and clinical research and plays an important role in fields as diverse as engineering, actuarial science, and sociology. In this dissertation, we develop new semiparametric Bayesian methodology for three problems from survival analysis: 1) adjustment for treatment crossover in randomized controlled trials (RCTs), 2) multilevel modeling of clustered survival outcomes when the cluster size is also informative, and 3) divide-and-conquer Bayesian inference for massive survival data. Our methods are semiparametric in the sense that we assume the covariates have a linear effect with regard to the log-hazard or the log- survival time; however, …

Quinone-Mediated Extracellular Electron Transfer In Escherichia Coli During Glucose Oxidation Metabolism, Megan Danielle Whisonant

Theses and Dissertations

The growing global demand for energy, ongoing reliance on fossil fuels, and increasing water pollution from industrial and anthropogenic sources present significant environmental challenges. In response to these issues, renewable and sustainable energy sources offer substantial potential for reducing dependence on fossil fuels and ensuring access to clean water. Microbial electrochemical systems (MESs) have emerged as promising, eco-friendly solutions for energy-efficient wastewater treatment and bioremediation. A key challenge in MESs development is facilitating effective electron transfer between microorganisms and electrode surfaces. The first chapter of this thesis discusses the fundamentals of MES types, explains mechanisms of extracellular electron transfer, and …

Action Research Integrating Heggerty’S Phonemic Awareness Instruction For Transfer Into Third-Grade Writing, Jennifer Elizabeth Jones

Theses and Dissertations

Writing requires the ability to encode phonemes to separate sounds to spell. Students who are mystified by print often find writing a laborious task. This action research investigated the impact of Heggerty's Bridge the Gap phonological instruction on third grade writing development, specifically focusing on elaboration. Recognizing that strong phonological foundations are crucial for both reading and writing success, this study addressed the gap in phonological instruction found in upper elementary grades. The research questions guided the research: What is the impact of phonological awareness instruction on third-grade students’ elaboration domain in writing? 2.) What are the third-grade students' perceptions …

The Potential Importance Of Microenvironment On Polymer Bound Chemical Reagents, Nathan Joseph Halsteter

Theses and Dissertations

In this thesis will provide a brief history of polymer bound reagents, their uses, and advancements. The importance of polymer microenvironments will be explored using a model kinetic resolution reaction utilizing polymer bound reagents to observe how changes in a polymer’s microenvironment effects the yield and selectivity of a reaction. It was found that there are copious factors that affect polymer bound reagents, and no direct conclusion could be drawn from the study.

Reactivity Of Redox-Active Carboranyl Diphosphines And Carboranyl Diphosphoniums: Metal-Free Pathways For Small Molecule Activations And Transformations, Amanda Lynn Humphries

Theses and Dissertations

Transition metal catalysis has been an integral part of synthetic chemistry for its ability to selectively activate strong substrate bonds, promoting numerous crucial transformations. Despite their utility, the precious metals that are often employed in these catalytic reactions suffer from several drawbacks (including high toxicity, low natural abundance, high costs, and low sustainability), increasing the motivation to design suitable metal-free alternatives. Towards this end, several ambiphilic main-group systems have been devised to show metal-like reactivity, such as carbenes, borylenes, and Frustrated Lewis Pairs. This manuscript will describe the ambiphilic reactivity of carborane-based phosphorus compounds, highlighting the unique metallomimetic reactivity that …

Characterizing Dissolved Organic Matter Composition In A Southeastern United States Watershed, Gwendolyn Marcelette Hopper

Theses and Dissertations

Dissolved organic matter (DOM) has important roles in many biogeochemical cycles. DOM is primarily composed of dissolved organic carbon (DOC), nitrogen, and phosphorus, and the processing of DOM is important for nutrient regulation and carbon cycling. In the coastal plains of the southeastern United States, there are many rivers and streams known as “blackwaters” with exceptionally high concentrations of chromophoric dissolved organic matter (CDOM) leached from terrestrial soils, coinciding with a region experiencing some of the nation’s highest rates of development. As changes in land use and climate continue to occur, DOM composition from natural to anthropogenically impacted systems can …

Determination Of Structure-Function Relationships In Hybrid Catalysts On Metal Oxide Supports, Joseph John Kuchta

Theses and Dissertations

Transition metal catalysis has revolutionized chemical synthesis, enabling efficient and selective transformations critical to the pharmaceutical, agricultural, and materials industries. However, traditional methods often rely on expensive, non-sustainable metals and harsh reaction conditions that generate significant waste. This dissertation explores a series of innovations aimed at bridging the gap between homogeneous and heterogeneous catalysis through the development of hybrid catalysts. These systems combine the molecular precision of homogeneous catalysts with the stability and practicality of heterogeneous supports, offering a pathway to more sustainable and scalable catalytic processes.

The first area of focus investigates nickel-based hybrid catalysts as a cost-effective and …

‘If You Design For The Future To Treat Of Witches:' Diabolic Service Magicians, Astrologers, And Witchcraft In John Dunton's Athenian Mercury, 1690-1697, Lauren Rebecca Rowe

Theses and Dissertations

Originating in the print stands of seventeenth-century London, the Athenian Mercury enjoyed a nearly miraculous seven-year run time as the most well-known and successful anonymous question and answer periodical of its time. Conceptualized and produced by bookseller John Dunton, the Mercury existed as an interface for intellectual discourse readily accessible to men and women. Kept entirely anonymous on the part of the author and reader, the intellectually curious could write questions to the Mercury and receive answers in turn on a vast variety of subjects twice a week. Aside from the more expected queries on science, love, mathematics, and religion, …

A Study Of Ci3t Implementation: Middle School Ela Teachers' Perceptions Of Tier 1 Academic Practices On Student Performance, Martha Kathryn Jenkinson

Theses and Dissertations

The purpose of this mixed methods action research study was to understand teachers’ perceptions of Ci3T tier 1 academic practices following the first year of implementation. Tier 1 instruction, delivered primarily by classroom teachers, is meant to meet the needs of a majority of students. Understanding teachers’ perceptions of program implementation, as well as reviewing student data to seek impacts of Ci3T on student learning, are important considerations when deciding how to improve the system. This study focused on the experiences and perceptions of English Language Arts teachers and Special Education teachers who work in ELA classes.

Data were gathered …

Hardware Accelerated Simulation Of Buck Converters Using Physics-Informed Neural Networks, James Clayton Crews

Theses and Dissertations

Physics-informed neural networks (PINNs) are an emerging machine learning method for learning the behavior of physical systems described by governing differential equations. Dc-dc power-electronic converters are used in a variety of industry applications such as motor drives or power supplies where real-time simulation is critical for control and safety. This thesis investigates physics-informed machine learning as an approach to develop a real-time digital twin for dc-dc power converters. Traditional numerical integration methods are used to approximate discretized behavior, and the results are compared with a trained PINN model. Modern ML frameworks (such as PyTorch and TensorFlow/Keras) are used to quickly …

The Impact Of Social Emotional Learning (Sel) Lessons On Students’ Mental Health Surrounding Standardized Testing, Margaret Denning

Theses and Dissertations

This qualitative action research examined the emotional impacts of standardized testing on 4th and 5th graders and the effects of targeted social-emotional learning lessons in a Title 1 school. Pre- and post-intervention data were gathered through surveys (Children’s Test Anxiety Scale) and focus group interviews. By employing thematic and narrative analysis, findings revealed significant initial cognitive anxiety, physical symptoms, and difficulties in self-regulation. Following the SEL intervention, the data indicated that students exhibited improved emotional resilience, reduced anxiety symptoms, and enhanced coping skills. Although the SEL interventions enhanced overall emotional well-being, anxiety was not fully eliminated. This study highlights the …

Explorations In Extremal Combinatorics: Graph Spectra, Codegree Squared Sum Of Hypergraphs And Lin-Lu-Yau Ricci Curvature, George Henry Brooks

Theses and Dissertations

This dissertation explores a variety of extremal problems in spectral graph theory, hypergraph Tur\'an theory in the $\ell_2$-norm, and Lin-Lu-Yau Ricci curvature. We begin by studying the maximization of linear combinations of eigenvalues in relation to the adjacency matrix of a graph. For a graph $G$ on $n$ vertices, we order its eigenvalues $\lambda_1 \geq \dots \geq \lambda_n$. First, we study a generalization of the maximum spread. Specifically, we consider the $(i,j)$-spread, defined as $\lambda_{i+1}-\lambda_{n-j}$, and aim to maximize that quantity over all simple graphs on $n$ vertices. We establish asymptotic bounds for all $i,j\geq 0$ and identify infinitely many …

Developing Mathematical Thinking And Reasoning For Students With Disabilities Through Professional Learning Communities, Dawn Pilotti

Theses and Dissertations

Professional learning communities (PLCs) are designed to improve learning outcomes for all students through educator collaboration. Guided by systems theory and supported by social cognitive, social practice and change theories, this longitudinal participatory action research study explored the development of an interdepartmental PLC, and its impact on mathematics teachers’ practices and students’ performance. Additionally, this study explored the relationship between participation in the PLC and participants’ collective efficacy. The study was conducted at a school for students with learning disabilities. The PLC included Grade 5 and Grade 6 mathematics teachers, occupational therapists, speech and language pathologists, a mathematics specialist, reading …

Mo Isotopes In The Aleutian And Costa Rican Arcs: Source Variability And Juvenile Crust Formation, Ekaterina Rojas Kolomiets

Theses and Dissertations

Chemical and physical transfer between the surface, lithosphere and asthenosphere at subduction zones leads to arc magmatism and continental crust (CC) production. Subduction zones magmas and associated volcanic products sample a variety of magmatic sources that contribute to their chemical compositions in various proportions. This dissertation contributes to the study of subduction zones magmatism by assessing the relative role of subduction inputs (sediments, altered oceanic crust – AOC – and serpentinite) as flux agents in the arc magmatism and in CC formation in subduction zones under the scope of Mo isotope systematics.

I present the first Mo isotope analyses form …

Exploring The Self-Assembly Of Functional Bis-Urea Macrocycles: M-Terphenyl Bis Urea Macrocycles And Triphenylamine Bis-Urea Macrocycles, Gamage Isuri Pramodya Wijesekera

Theses and Dissertations

Porous materials have gained significant attention due to their diverse applications in catalysis, separation, and molecular storage. Among them, self-assembled macrocycles represent a unique class of functional materials that leverage non-covalent interactions to form well-defined architectures with pores of controlled size. This thesis explores the design, synthesis, and self-assembly of bis-urea macrocycles in both solid-state and solution-phase environments, with a particular focus on supramolecular polymerization mechanisms and the emergence of kinetically trapped states.

The first chapter of this thesis presents a detailed overview of self-assembled porous materials, categorizing them based on pore dimensions and discussing their significance in catalysis, separation, …

Two Dimensional Van Der Waals Magnet, Cheongheon Lee

Theses and Dissertations

Conventional charge-based memory has reached its limits in improving energy efficiency while scaling down size. Consequently, memory utilizing 2D magnetic materials has emerged as an alternative. 2D Van der Waals (VdW) magnets are ultrathin magnets with unique properties that make them optimal for this purpose. Utilizing the weak interlayer coupling via VdW interaction has enhanced the possibility of integrating diverse materials to create heterostructures. The integration of spintronics requires not only stable magnetization but also an effective switching mechanism. Various external influences have been experimentally tested, such as the proximity effect, external magnetic field, gate voltage, and temperature dependence. This …

Physics Oriented Deep Learning For Material Prediction And Generation, Nihang Fu

Theses and Dissertations

The discovery of new materials is critical to advancing various industries, but traditional experimental methods for materials discovery remain slow and resource-intensive. Recent advances in machine learning (ML), particularly deep learning (DL), have greatly improved and accelerated two main aspects of modern computational material discovery: material design (e.g., material generation) and material screening (e.g., property prediction). However, a key challenge remains: standard ML models often struggle to perform domain-specific tasks effectively. Incorporating domain-specific knowledge, specifically the underlying physics of materials, into ML/DL models is key to improving the accuracy and reliability of material generation and prediction models.

This dissertation discusses …

On A Conjecture On Covering Systems And An Irreducibility Question On Sparse 0,1-Polynomials, Alexandros Kalogirou

Theses and Dissertations

In 1952, H. Davenport posed the problem of determining a condition on the minimum modulus $m_0$ in a finite distinct covering system that would imply that the sum of the reciprocals of the moduli in the covering system is bounded away from 1. In 1973, P.~Erd\H os and J.~Selfridge indicated that they believed that $m_0$ > 4 would suffice. We provide a proof that this is the case in Chapter 2. Chapters 3 and 4 are dedicated to showing that $0,1$-polynomials of high degree and few terms are irreducible with high probability. Formally, let $k\in\mathbb{N}$ and $F(x)=1+\sum_{i=1}^kx^{n_i}$, where $ 0

In Vivo Analysis Of Fe-S Cluster Assembly And Iron Homeostasis In Escherichia Coli, Dexter Mclaurin Reasons

Theses and Dissertations

Iron-sulfur (Fe-S) clusters are an essential cofactor for a wide range of cellular processes, and their assembly and storage require tight regulation.

In Escherichia coli (E. coli), there are two pathways of Fe-S cluster assembly, the Isc and the Suf pathways. The Isc pathway is used under good growth conditions, and the Suf pathway is used under iron starvation and oxidative stress conditions. Once the cluster has been assembled on the scaffold protein of either pathway, it is transferred to Fe-S cluster trafficking proteins. In E. coli, the monothiol glutaredoxin GrxD and the BolA-type proteins BolA and IbaG …

Some Likelihood-Based Methods For Clustering Functional Data, Tong Shan

Theses and Dissertations

The analysis of functional data is an increasingly relevant part of statistics. The exploratory data analytic method of cluster analysis plays a very important role in different fields. Over the years, researchers have developed many clustering approaches, striving to achieve more accurate and efficient clustering. In Chapter 1, we aim to improve the accuracy of our outcome when clustering functional data. To achieve this goal, we use a predictive likelihood function which serves as an objective function to optimize in order to determine the most appropriate clusters. To optimize the objective function over the space of clustering partitions, we produce …

On Berge Pancyclicity For Uniform Hypergraphs, Teegan Cole Bailey

Theses and Dissertations

An $n$-vertex graph $G$ is \textit{hamiltonian} if it contains a length $n$ cycle as a subgraph. A stronger notion of hamiltoncity is pancyclicity. A graph $G$ is \textit{pancyclic} if $G$ contains a cycle of length $k$ for every $3\leq k \leq n$. Dirac's classical result on hamiltonicity states that if an $n$-vertex graph $G$ has minimum degree $\delta(G)\geq \frac{n}{2}$, then $G$ is hamiltonian. Under the same minimum degree condition as Dirac, J. A. Bondy showed that $G$ must also be pancyclic or the exceptional graph $K_{\frac{n}{2}, \frac{n}{2}}$. In 1971, Bondy proposed a so called meta-conjecture claiming that \textit{``almost any nontrivial …

Effect Of Growth Conditions On The Performance Of Vertically Conducting Beta-Ga2o3 Diodes On 4h-Sic Substrate By Mocvd, Nifat Jahan Nipa

Theses and Dissertations

This thesis highlights the critical influence of doping strategies, specifically co-delta doping with silicon (Si) and indium (In), on improving the structural quality and device performance of β-Ga₂O₃-based Schottky barrier diodes (SBDs). To achieve better thermal management, β-Ga₂O₃ thin film was grown on bulk 4H-SiC substrates using the Metal-Organic Chemical Vapor Deposition (MOCVD) technique, renowned for its precise control over composition, thickness and doping profile. The ultra-wide bandgap (UWBG), high critical breakdown field and low turn-on resistance of β-Ga₂O₃ make it a strong candidate for next-generation power electronics and short-wavelength detection in extreme environments. However, the presence of structural defects …

Artificial Intelligence In Sport Management: A Systematic Review, Scale Development And Validation, And Implications, Kemardo Tyrell

Theses and Dissertations

The democratization of intelligent systems and their ubiquitous presence across the sport industry have created an urgent need to understand the current environment and how stakeholders perceive artificial intelligence (AI) as it reshapes decision-making, engagement, and organizational design. This three-manuscript dissertation conceptualizes artificial intelligence as a contested domain shaped by stakeholder meaning-making, consumer perception, and shifts in organizational practice. The first manuscript provides a systematic review of AI in sport management using the PRISMA framework, mapping how AI has been conceptualized as a methodological tool or contextual innovation across the sport industry segmentation (performance, production, and promotion). The second manuscript …

The Impact Of The Flipped Learning Approach On Student Engagement In A High School Chemistry Classroom, Alana Lyn Hicks

Theses and Dissertations

This mixed-methods action research study investigated the impact of the flipped classroom approach on student engagement and attitudes within a science classroom. Data was collected using student-reported responses on the Classroom Engagement Inventory, Motivated Strategies for Learning Questionnaire, student journal entries, teacher reflective journals, and an observation tracking chart kept by the classroom teacher. Findings revealed that the flipped classroom model significantly increased affective and cognitive engagement among students in a larger class size, as well as for medium-achieving students and girls. These results suggest that while the flipped classroom has the potential to enhance engagement, its effectiveness is influenced …

Explainable Process Recommendation Through Multi-Contextual Grounding Of Dynamic Multimodal Process Knowledge Graphs, Revathy Venkataramanan

Theses and Dissertations

Can I eat this food or not? Is this food suitable for diabetes and why? Which AI pipeline is best suited for a given task and dataset? How should an end-to-end pipeline be constructed? These questions differ from factual question-answering tasks. Recipes and AI pipelines are processes consisting of several entities interacting with each other. A recipe consists of ingredients, cooking methods, and their interactions, while an AI pipeline includes datasets, preprocessing techniques, models, hyperparameters, tasks, and results. Each entity must be analyzed individually, and collective inferencing is performed to derive the final decision. This decision-making process, known as compositional …

The Tur Nout Effect: Challenging The Median Voter Theorem, George Thomas Rogers

Theses and Dissertations

The classical Median Voter Theorem (MVT) predicts that, in a two-party system with majority rule, candidates will converge toward the ideological center to capture the median voter. This logic, grounded in spatial models of political competition, assumes full voter participation and fails to account for the growing ideological polarization in modern democracies. This thesis reevaluates the MVT by incorporating probabilistic turnout into a utility-based model of voter behavior. It theorizes that turnout is shaped not only by ideological proximity but also by expressive motivations, including both strong affinity and strong aversion to candidates. A novel measure of turnout utility is …

A Spatial Scan Statistic For Group Testing Data, Vincent Onyame

Theses and Dissertations

Group testing involves pooling specimens from multiple individuals and offers an efficient means to surveil low-prevalence pathogens, but poses challenges for spatial cluster detection when only pooled results are observed. In this thesis, we develop a spatial scan statistic tailored to group-testing data with variable pool sizes. The statistic compares a null hypothesis of a homogeneous infection rate across all clusters to an alternative hypothesis that infection probabilities differ inside and outside a candidate cluster, with both models fitted by maximum likelihood estimation. We approximate the null distribution of the maximum likelihood ratio test via Monte Carlo simulation.

Through a …