Digital Commons Network^™

Reduced Order Models Of Hydrodynamically Interacting Flapping Wings, Jose Pabon

Dissertations

Fish schools exhibit a collective behavior and self-organization that is mediated by hydrodynamic interactions between individual fish. However, the long-time evolution of hydrodynamically interacting collectives is challenging to investigate due to the persistent influence of long-lived vortical structures, and the high-resolution requirements of direct numerical simulation at large Reynolds numbers. Reduced-order models have therefore played an important role in theoretical investigations of collectives of swimming bodies. The main results detailed herein are several new reduced-order models of swimmers that self-propel by flapping, i.e., by executing a prescribed periodic rigid body motion. The models are extensions of a discrete-time dynamical system …

Harnessing Graphs For Knowledge Representation In Natural Language Processing, Uras Varolgunes

Dissertations

This work proposes innovative methods for integrating domain-specific knowledge into natural language processing tasks through the use of graphs, aiming to enhance the performance of models across various domains, including finance and healthcare. Several novel approaches are proposed that fuse graph structures with modern deep learning techniques, addressing the challenges of missing word embeddings, label prediction, and graph representation learning for large language models.

First, a powerful embedding method built on top of the recent advances in latent graph learning is introduced to address the critical problem of word embedding imputation. Second, a graph-enhanced label attention model designed for medical …

Optimizing Hip And Knee Assistance For Walking And Sit-To-Stand Transitions: An Intrinsic Muscle Mechanics Based Predictive Approach, Neethan Ratnakumar

Dissertations

As the global population ages, the demand for wearable assistive technologies continues to rise, driven by their potential to enhance mobility and independence in older adults. Effectively designed controllers for lower-limb exoskeletons to assist sit-to-stand (STS) and walking are crucial for delivering efficient, safe, and comfortable assistance during daily activities. Traditionally, controller optimization involves biomechanical modeling and user-specific customization. Musculoskeletal simulations play a central role in this process by providing insights into human-exoskeleton interaction dynamics, thereby informing and refining control strategies.

This work presents a simulation-driven approach for developing exoskeleton controllers for walking and STS using two distinct methods: optimal …

Development And Implementation Of Novel Mass Spectrometric Methods For Metabolism Studies In Drug Discoveries, Huifang Yao

Dissertations

The field of drug discovery has evolved significantly over the past few decades, with a growing emphasis on understanding the metabolic pathways and biotransformation processes that influence the pharmacokinetics and pharmacodynamics of drug candidates. Novel mass spectrometric methods have emerged as powerful tools in this domain, facilitating the comprehensive analysis of metabolic profiles and enabling the identification of metabolites with implications for safety, efficacy, and overall drug development. However, challenges remain in quantifying metabolic flux—an essential aspect of understanding drug action—particularly due to the limitations of traditional isotope kinetic assays, which often involve lengthy sample preparation and the use of …

Multi-Messenger Diagnostics Of The Origin And Transport Of Solar Energetic Particles, Meiqi Wang

Dissertations

Impulsive solar energetic electron events (SEEs) are a common phenomenon originating from the Sun. They are characterized by rapid onset and brief duration, and are commonly associated with solar flares. Solar radio bursts, which offer a rich variety of diagnostic tools for solar activities, exhibits a close relationship with impulsive solar energetic electron events. Such diagnostics are particularly powerful when combined with multi-wavelength remote sensing and in situ observations. The dissertation focuses on combining state-of-the-art microwave imaging spectroscopy data obtained by the Expanded Owens Valley Solar Array (EOVSA) with other multi-messenger observations to investigate the origin of impulsive solar energetic …

Understanding Structure-Property Relationships Within Polyolefin-Derived Vitrimer Systems, Mikaela Sadri

Dissertations

Polyolefins are extremely ubiquitous materials due to their satisfactory material properties, ease of synthesis, and low cost. Unfortunately, their extensive use has led to a global plastic waste mismanagement problem. As such, notable efforts have recently focused on converting these commodity polymers into vitrimers, or dynamic networks, to extend their use-life and tailor their properties. However, the fundamental polymer physics of these emerging materials, remain largely underexplored, hindering their widespread implementation. To address this challenge and enable a more sustainable future, the overarching goal of my dissertation research is to understand the fundamental structure-property relationships within complex polyolefin-derived vitrimer systems. …

An Alternative Approach To Non-Relativistic Quantum Mechanics In Curved Space, Robert A. Hulsey

Dissertations

In the research presented in this dissertation, we propose an alternative formulation of non-relativistic quantum mechanics in curved spaces (Riemannian manifolds). Some toy quantum models (2D quantum harmonic oscillator in Poincaré half-plane model and the flat chart model of hyperbolic 2-space) are studied to understand the physical implications of this alternative formulation.

Reinforcement Learning And Virtual Human Animation: A Novel Approach To Data-Driven Animation, Portraying Dynamic, Flexible Human-Like Behaviours, Vihanga Gamage

Dissertations

Virtual characters require animation capable of portraying dynamic, context-sensitive human-like behaviours. Several approaches to generating such animation have been developed, but each carries limitations. Motion capture can produce high-fidelity animation but is expensive and ill-suited to systems that must respond in real time. Physics-based reinforcement learning (RL) enables flexible, dynamic behaviour portrayal, yet relies on simulation feedback signals that are unavailable for social gestures. Supervised approaches can learn social behaviours from motion capture data but yield agents with limited flexibility and generalisation.

This thesis presents RLAnimate, a model-based, data-driven RL framework for character animation that enables a single agent to …

Multiple Monochromatic Subgraphs In Edge-Colored Graphs, Emma Felicity Jent

Dissertations

Ramsey theory, though a relatively young branch of mathematics, has captivated the attention of graph theorists, combinatorialists, and theoretical computer scientists alike through its raw beauty, versatility, and powerful applications. Before it emerged as a branch of mathematics, the central idea of Ramsey theory appeared in the form of three lemmas in three separate papers by three different mathematicians working on three distinct areas of research. The first such lemma was published by David Hilbert in 1892, followed by the second lemma published by Issai Schur in 1916. However, Frank Ramsey’s renowned lemma, published in 1930, compelled mathematicians to establish …

Mechanistic And Evolutionary Insights Into A Group Of Nicotine And Hydroxynicotine Degrading Flavoenzymes, Zhiyao Zhang

Dissertations

Flavoprotein amine oxidases (FAOs) are key enzymes in various kinds of metabolic pathways, mediating redox reactions via flavin cofactors. While most FAOs function as oxidases that readily reduce oxygen to hydrogen peroxide, a few outliers of the FAO family act as dehydrogenases that suppress the reaction with oxygen. The molecular basis for this divergence in function remains poorly understood.

The work presented in this study investigates the fundamental mechanisms of how flavincontaining enzymes activate or suppress their reaction with different electron acceptors to achieve high turnover rates. The overall body of work is divided into three different sections that (1) …

Collaborative Action In Education: Empirical Explorations Of The Role Of Partnerships In College Readiness Programs, Jose A. Sanchez

Dissertations

Education gaps exist in the United States in large part because not everyone has equal access to the educational resources or role models that will prepare them to seek a college education. To help combat this phenomenon, Federal and State Governments have promoted college readiness programs via collaborative partnerships between school districts, on the one hand, and colleges and universities, on the other.

To better understand the role that partners can play in creating and sustaining college-readiness programs, this study focused on the history and current practices of collaborations involving oversight of college readiness programs in two school districts. Partnership …

Investigating Undergraduate Students’ Statistical Literacy In Media Contexts, Samuel Waters

Dissertations

As the uses of data in society continue to expand, it is vital to prepare students to engage with data in meaningful and critical ways. Undergraduate introductory statistics courses provide an opportunity for students to develop important knowledge and skills for interpreting and questioning statistical information in social contexts. The purpose of this convergent mixed methods study was to use quantitative assessment data and qualitative interview data to investigate the statistical literacy of students in an undergraduate introductory statistics course in media contexts. This study defined statistical literacy using Watson and Callingham’s (2003) six-level construct. Specifically, this study investigated students’ …

Students’ Ability To Transfer Organic Chemistry Concepts To Metabolic Reactions, Timothy Jones

Dissertations

Bridging foundational knowledge learned in prerequisite courses like organic chemistry to higher-level courses like biochemistry represents a significant challenge in science education, often hindering deeper student understanding and future knowledge application. The purpose of this dissertation was to investigate students’ ability to transfer and apply their understanding of organic chemistry when reasoning through metabolic reaction problems often seen in biochemistry courses. The research questions guiding the project were two-fold:

Q1 What are the organic chemistry reaction concepts deemed foundational to understanding metabolism by experts in the field?

Q2 What is the student’s ability to transfer knowledge of organic chemistry reactions …

Shifting Instructional Planning Practices: Exploring High School Mathematics Teachers' Perceptions Of Integrating The Do The Math Protocol Into Collaborative Instructional Planning, Lillian M. Gordon

Dissertations

This qualitative case study explores the perceptions of high school mathematics teachers regarding the implementation of the Do the Math protocol during collaborative instructional planning. This study investigates how the use of a structured planning tool can support professional growth and instructional improvement. Over five weeks, participants engaged with the protocol to collaboratively plan instruction. Data was collected through interviews, observation of collaborative instructional planning sessions, and analysis of instructional artifacts. Findings revealed two major themes. First, the protocol contributed to building content and pedagogical knowledge by deepening teachers’ understanding of math standards, promoting intentional collaboration, and encouraging the sharing …

The Impact Of A Multilingual Learner Professional Development On Teacher Self-Efficacy And Student Perceptions Of Teacher Support, Mark A. Bryan

Dissertations

The population of multilingual learners is struggling to adapt to mainstream classes because the educational system has failed to support them on the same level as native English speakers. The gap in achievement and lack of teacher preparation demonstrates a clear need to support teachers who educate them. This study, a nonequivalent (pretest and posttest) control-group design combined with a cross-sectional survey design, addressed the effectiveness of a professional development series focused on best practices for teaching secondary math to multilingual learners. The professional development intervention consisted of one 45-minute initial session followed by twelve 15-minute mini lessons throughout the …

The Development Of High Throughput Assays For Identification And Evaluation Of Small Molecule Modulators Of The Pri-Microrna-18a—Hnrnp A1 Interaction, Emile N. Van Meter

Dissertations

Therapeutics targeting RNA is a rapidly growing field. While only 1.5% of the human genome encodes genes for protein, over 70% o=f the human genome contains the genes for noncoding RNAs that regulate protein expression and function. Expanding the paradigm of small molecule drug discovery from traditional protein targets to include RNA would broaden the therapeutic landscape and provide new methods to modulate previously undruggable targets. miRNAs (miRs) have been found to be aberrantly expressed in many disease states, including neurodegenerative diseases and cancers making them promising therapeutic targets. The production of functional, mature miRs requires multiple proteins in a …

Measurements And First Principles Calculations On The Non-Centrosymmetric Superconductor Aupb3, Meena Shrestha

Dissertations

AuPb₃ is a non-centrosymmetric superconductor that crystallizes in a tetragonal structure and undergoes a superconducting transition at 4.4 K. Non-centrosymmetric superconductors that lack inversion symmetry are predicted to have an admixture of spinsinglet and spin-triplet symmetry induced by strong antisymmetric spin-orbit coupling (ASOC).

In this work, we investigated the normal and superconducting properties of AuPb₃. We also carried out the Density Functional Theory (DFT) calculations to study the strength of ASOC and its impact on vibrational and electronic properties. A high-quality polycrystalline sample of AuPb₃ was grown and characterized by powder x-ray diffraction, scanning electron microscopy, …

Enhanced Point Cloud Generation From A Novel 360° Underwater Lidar, Olagoke E. Daramola

Dissertations

This dissertation presents novel algorithms to improve the mapping capabilities of a 360-degree underwater Pulsed Laser Line Scanner LiDAR (PLLS-360°). Due to its 360° field-of-view (FOV), the PLLS-360° is a compact full-waveform omnidirectional imager suitable for seafloor mapping, underwater asset inspection, object detection, ice-sheet mapping, and construction progress monitoring. The proposed methodology includes an improved waveform fitting technique for saturated waveform recovery, detection array response correction, radiometric corrections, and fusion of LiDAR and sonar bathymetric datasets. The first part of this dissertation assesses the LiDAR’s performance and describes how the data for this unique 360° FOV architecture is processed. The …

Perceptions Of Department Chairs And Program Directors Of Ethnic Studies In The California State University System: A Convergent Parallel Mixed Methods Study, Christopher Jarrett Cox

Dissertations

The purpose of this dissertation study is to explore the conditions of Ethnic Studies departments and programs in the California State University (CSU) system nine years after the release of the CSU Ethnic Studies Task Force report released in 2016. Using a convergent parallel mixed methods analysis, this dissertation revisits several questions from the original CSU survey to assess the effectiveness of Ethnic Studies units in the CSU. Respondents to the survey included 13 of the 58 recognized department chairs and program directors for Ethnic Studies units among the 23 campuses of the CSU system, and interview participants included 5 …

"Are You My Counselor?" A Call To Action How Latinx General Counselors Can Support Latinx Student Retention Rates At California Community College Hispanic-Serving Institutions, Valentín García Cabrera

Dissertations

Latinx students comprise the largest population within the California Community College (CCC) system, but experience disproportionately lower retention rates. This dissertation used a phenomenological qualitative design and testimonios collected from Latinx general counselors to explore factors influencing Latinx student retention. Sixteen tenured Latinx general counselors from ten Northern California Hispanic-serving community colleges served as participants. Guided by two research questions, the study explored counselors’ perspectives on the factors influencing Latinx community college students’ retention and the counseling strategies, services, and resources that General Counseling Departments should provide to support Latinx student retention. Grounded in Latinx Critical Race Theory, the study …

Contracts, Communication, And Contextual Integrity: A Case Study About Student Data Use In Higher Education, Joseph Fessehaye

Dissertations

This case study examines the contractual agreements between the University of Missouri System and the California State University System with the Educational Advisory Board (EAB), focusing on how these contracts align with institutional student data privacy policies. The research utilizes a Policy Document Analysis approach and explores both universities’ strategic plans, student data privacy guidelines, and the third-party agreements with EAB, using a Contextual Integrity framework to analyze how student data is managed and protected. Through the analysis of these documents, this dissertation investigates whether the flow of student data within the context of these contracts meets institutional privacy standards …

Engagement Of Secondary History Social Science Teachers With Professional Development: A Phenomenological Study, Suzanne Paulazzo

Dissertations

Secondary social science teachers tend to feel disengaged and frustrated with their professional development (PD) experiences. They also feel that recommended meaningful practices appear to be time-consuming, require extra hours of preparation, and rely heavily on collaboration. Using phenomenological methodology, the dissertation research investigated secondary social science teachers' perceptions of their roles as educators, their professional growth, and their motivations for engaging in professional development opportunities. Nine male and one female teacher participants from a History-Social-Science Department in an urban public school in Northern California participated in an interview. This study addressed the following research questions: How do teachers perceive …

Nanoporous Gold Nanoparticles And Model Membrane Systems Applied To The Study Of Lipopolysaccharide (Lps), Dhanbir Lingden

Dissertations

Lipopolysaccharide (LPS), a key structural component of Gram-negative bacteria, is a major trigger of sepsis and septic shock, the systemic inflammatory conditions responsible for millions of deaths annually. Even at concentrations as low as 1 ng/mL, LPS can activate the immune system and initiate inflammatory cascades. According to the Global Burden of Disease Study 2017, sepsis accounted for 48.9 million cases globally, with 11 million deaths, emphasizing the urgent need for improved diagnostic and therapeutic strategies.

Accurate and rapid detection of LPS is vital for early intervention and improved clinical outcomes. While traditional detection methods are still widely used, modern …

Bridging The Skills Gap: A Design Thinking Mixed Methods Approach To Workforce Readiness, Bernetta Matory–Sylvester

Dissertations

No abstract provided.

Variable Importance, Knockoff Filters, And Improving False Discovery And False Negative Rates, Nicholas Ehlman

Dissertations

Tree ensemble methods such as Random Forests and Boosted Trees have introduced a range of variable importance statistics, offering powerful tools for feature selection. The advent of knockoff filters marked a significant advancement by combining the use of these variable importance statistics with the ability to control the False Discovery Rate (FDR). However, achieving a low FDR frequently comes at the cost of a high False Negative Rate (FNR), limiting the power of such approaches. In this work, we propose a novel method for leveraging knockoff variables to keep both FDR and FNR low. While this method does not have …

Enzymatic Characterization Of Bacterial Enzymes And Inhibitors As Potential Antibiotics With New Mechanisms Of Action, Emma Helene Kelley

Dissertations

Bacteria have become increasingly resistant to antibiotics, therefore there is an urgent need for new drug classes of antibiotics to help fight antibiotic infections. To this end, our research is focused on inhibitors of dizinc metalloenzymes N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE), an enzyme in the lysine biosynthesis pathway, N-acetyl-L-ornithine deacetylase enzyme (ArgE), an enzyme in the arginine biosynthesis pathway, and sodium-dependent NADH: ubiquinone oxidoreductase (Na+-NQR) enzyme, a respiratory complex enzyme as promising drug targets. DapE, ArgE, and Na+-NQR and are only present in bacteria, including ESKAPE pathogens that can cause potentially deadly infections, thus inhibitors of DapE, ArgE, and Na+-NQR offer …

Development Of Novel Force Fields For Metal Ions, Madelyn Smith

Dissertations

Many biological proteins require the presence of a metal ion in order to properly function. However, metal ions’ complex nature charge poses several challenges to accurately and efficiently simulate computationally. For example, metal ions can exhibit multiple oxidation states, electronic state degeneracy, flexible coordination numbers, and significant polarization effects. To address these problems, this dissertation aims to enhance force fields for modeling metal ions in molecular dynamics simulations. First, a comprehensive set of van der Waals radii for metal ions is derived, demonstrating the importance of using physically meaningful parameters in force fields. Second, a comprehensive set of atomic and …

The Impact Of Substrate Structure And Catalyst Identity On The Lewis-Acid Catalyzed Carbonyl-Olefin Metathesis Reaction, Cory William Schneider

Dissertations

The formation of carbon-carbon double bonds is one of the most important transformations in organic chemistry, as they are integral to the structural scaffold of many organic molecules. Thus, the development and understanding of reactions that form such bonds is crucial. Lewis-acid catalyzed carbonyl-olefin metathesis is one such reaction. Like many others, this reaction is sensitive to both the identity of the catalyst, as well as the structure of the substrate. In this dissertation, I present empirical and theoretical works investigating how the catalyst identity and the substrate direct the reactivity of the Lewis-acid catalyzed carbonyl-olefin metathesis reaction.

A Design Based, Mixed Method Study On Evaluating Traditional Grading Practices And The Implications For Mastery Learning And Educational Equity In A Midwestern School District, Christina Kirchner

Dissertations

“Grades are an essential currency of our schools. Schools, colleges and employers use grades to determine many important, and in some cases, life-altering decisions-college admission, financial aid and scholarships, athletic eligibility, promotion, retention, awards, and supports” (Feldman, 2018, p. 3). Grading is not addressed in teacher preparation programs, or within professional development during teachers’ careers; teachers have chosen their own way to grade guided by their own personal experiences, uninformed of research or best practice. Using a human centric, design-based approach, the researcher identified multiple discrepancies with grading practices among the K-12 school organization. Within the discrepancies, other issues were …

Impact Of Student Voice In The (Dis) Engagement Of Middle School Students In Urban Elementary School And Academic Achievement, Valandra N. Lloyd

Dissertations

This formative mixed-methods evaluation study explores the impact of culturally inclusive teaching practices on student voice, engagement, and academic outcomes among middle school students in an urban elementary school. Grounded in the theoretical frameworks of Culturally Relevant Pedagogy (Ladson-Billings), Culturally Responsive Teaching (Gay), and Culturally Sustaining Pedagogy (Paris & Alim), the study addresses persistent academic disparities experienced by students of color. Using classroom observations, student surveys, student focus groups, and teacher interviews, the research examines how teacher facilitation and inclusive classroom environments affect behavioral, emotional, and cognitive engagement. Findings will inform actionable strategies to amplify student voice and promote culturally …