Digital Commons Network^™

Explainable Ai For Neural Text Classification Models: Robustness And Knowledge Locality, Christopher Burger

Electronic Theses and Dissertations

Powerful but complex models have seen extensive adoption within recent years due to their performance across a wide range of tasks. However, this effectiveness has come at the cost of a limited understanding of how exactly these models make their decisions. This lack of understanding has justifiably slowed integration of these models within domains where serious consequences can result due to error like medicine or finance. In response, the discipline of explainable AI (XAI) has arisen to provide justification for why these models work the way they do. One of the most prominent tools in XAI has been the local …

Cationic Charge-Shifting Polymers As Improved Vectors For Nucleic Acid Delivery, Alexander Fortenberry

Electronic Theses and Dissertations

This work investigates the development and application of charge-shifting polycations for gene delivery, focusing on their synthesis, characterization, and applications for in vitro mRNA delivery. Utilizing poly(2-vinyl-4,4-dimethylazlactone) (PVDMA), this study explores modifications with various reactive handles, such as alcohol, thiol, and amine groups, to create cationic amide-, ester-, and thioester-functionalized polycations. These modifications aim to exploit the charge-shifting capabilities of the polycations to form stable polyplexes with nucleic acids, promoting the efficient intracellular release of the genetic cargo.Initial studies first examine the charge-shifting properties of PVDMA-based polycations under different pH and temperature conditions. This work highlights the potential of these …

Ecological And Evolutionary Ramifications Of Host-Parasite Interaction In Aquatic And Model Ecosystems, Akacia Halliday-Isaac

Electronic Theses and Dissertations

Host-parasite interactions are ubiquitous and have negative risks and consequences on individual, population, and evolutionary scales. These risks and consequences include altered population densities, changes in interspecies interactions, and rapid changes in host phenotypes. In this thesis, I seek to understand the ecological and evolutionary ramifications of host-parasite interactions within ecosystems. To do this, I investigated the presence and environmental correlates of potential host-parasite interactions in a freshwater ecosystem and used a model ecosystem to explore how past host-parasite coevolution affects community assembly dynamics and future adaptation in the presence of new stressors. To examine the presence of potentially parasitic …

Rovibrational Characterization Of Astrochemically-Relevant Small Oxides, Olivia Ann Harwick

Electronic Theses and Dissertations

Quantum chemical techniques can serve to unravel the chemical complexity in both the laboratory and astronomical observation. However, complete sets of spectral reference data for some molecules are often absent from the current chemical census, but modern quantum chemistry can provide full spectral characterization for nearly any small molecule of interest. This thesis provides such complete, high-level, and modern rovibrational information for a series of small molecules. More specifically, quartic force fields elucidate anharmonic vibrational frequencies and rotational constants for small, cyclic oxides, all of which contain either aluminum, silicon, or carbon. Such information facilitates definitive detection in observational, chemical …

Mindfulness And Mathematics: The Relationship Between A Mindful Teacher And Mathematics Intervention, Ave Mayeux

Electronic Theses and Dissertations

Adolescents in American classrooms are currently required to fulfill multiple roles, making them particularly vulnerable to stress due to intense academic demands and social pressures. This stress can be particularly challenging for adolescents who struggle with stress, anxiety, depression, and/or self-regulation. Previous research indicates a positive correlation between mindfulness practices and reduced anxiety, improved social skills and interactions, enhanced academic performance, and better self-perception. This self-study explored the implementation of mindfulness exercises in a mathematics intervention classroom by adapting and creating appropriate resources, and facilitating mindfulness exercises suitable for adolescent students. Data in this self-inquiry study was generated through meticulous …

Performance Of A Selective Amplify-And-Forward Scheme For Two-Users With Two-Relays In Rayleigh Fading And Log-Normal Shadowing Channels, Mahdia Tahsin

Electronic Theses and Dissertations

Relays serve as virtual antennas in wireless networks, fostering spatial diversity between the source and destination to enhance coverage, signal quality, and network reliability. Among the various relay-assisted communication approaches, amplify-and-forward (AF) is widely favored for its reduced computational complexity. The selection of an optimal relay is crucial for maximizing network performance, constituting a significant challenge in wireless communication. Hence, optimal relay selection has emerged as a pivotal area of research. In this thesis, we investigate the potential benefits of implementing relay selection schemes in AF relay networks featuring two source-destination pairs and two relays. Our analysis focuses on two …

Acoustic Localization In Reverberant Environment, Xing Yang

Electronic Theses and Dissertations

The main goal of this dissertation is to develop algorithms to accurately locate and detect underwater oil leakages through sounds emitted by oil-induced bubbles recorded by passive hydrophones. These algorithms aim to create an early warning system to prevent or identify catastrophic oil spills from pipelines, wellheads, and seafloor seepage.

On Saturation Numbers Of Double Stars, Lei Zhong

Electronic Theses and Dissertations

A graph G is H-saturated if G contains no copy of the graph H, but for any missing edge e of G, there exists a copy of H in G+e. The saturation number of H, denoted by sat(n, H), is the minimal number of edges among all H-saturated graphs with n vertices. The study of saturation number begins with a beautiful result presented by Erdös, Hajnal, and Moon [14] who calculated the saturation number of a complete graph along with the identification of the unique graph achieving this number.

Graphene-Based Multilayer Polymer Nanocomposite Systems For Force Protection Applications, Mohammad Mansourian Tabaei

Electronic Theses and Dissertations

This work focuses on designing and optimizing a multilayer polymer system (MLPS) for force protection applications, consisting of a front layer, sublayer, and back layer. The front layer was developed using high-concentration graphene nanoplatelet (GNP)-enabled polymers, specifically (poly vinyl alcohol) PVA and (polyurea) PU, as alternatives to brittle ceramic layers. The sublayer was tailored using ABS-GNP composites as a replacement for the traditional Kevlar middle layer. In the development of the front layer, PVA-based nanocomposites were optimized with a specific dispersing agent to enhance mechanical and thermal properties. These nanocomposites demonstrated significant improvements in stiffness, storage modulus, and energy dissipation, …

"'This May Not Be War, But Rather Statesmanship': Sherman's March Through Griswoldville, Milledgeville, And Greater Savannah", Matthew Ryan Lempke

Electronic Theses and Dissertations

This dissertation argues that four communities in Confederate Georgia visited by Union soldiers during Sherman’s March to the Sea reorients our understanding about the state’s continued ability to resist the United States military, the level and variations of destruction, the rationales and motivations behind targeted actions, the multiplicity of experiences among diverse participants, willing and unwilling alike, and of the campaign’s broader effectiveness. The first two communities, Griswoldville and Milledgeville, were indispensable locations that set in motion a coalescence of military and political setbacks from which Confederate Georgia did not recover. As the march progressed and entered coastal communities, the …

Effects Of Off-Season Fall-Winter Farm Field Flooding On Nitrogen Gas Production, Andrew Rosson

Electronic Theses and Dissertations

Increased nitrogen (N) fertilizer use and cultivation of N-fixing crops have dramatically increased agricultural N inputs to the global N cycle. Excess N on agricultural lands is highly susceptible to loss through runoff or atmospheric emissions, potentially as a greenhouse gas (GHG). Nitrous oxide (N2O), a GHG with a warming potential ~300 times that of carbon dioxide (CO2), primarily enters the atmosphere through denitrification, which converts bioavailable nitrate (NO3-) to inert nitrogen gas (N2), with N2O as an intermediate. Wetlands are crucial for de-nitrification and N regulation due to their wet, anoxic soils, but have declined worldwide, including substantial losses …

Exploring African American Female Students' Choice Of Stem Major At Rust College, Shatara Hall

Electronic Theses and Dissertations

In comparison to the rest of the United States population, African American women are undeniably inadequately represented in the fields of science, technology, engineering, and mathematics (STEM). As one of the oldest historically black colleges in Mississippi, Rust College has the social responsibility to increase the presence and contributions of minorities in STEM. Since the enrollment of African American females is greater than that of African American males at Rust College, the college has the fortuity to assist in increasing the diversity in STEM for both race and gender. This DIP utilizes Intersectionality Theory as the conceptual foundation to explore …

Dependence And Mixing For Perturbations Of Copula-Based Markov Chains, Mathias Nthiani Muia

Electronic Theses and Dissertations

This work explores the impact of perturbations of copulas on dependence and mixing properties for stationary ergodic Markov chains. We focus on two types of copula perturbations and establish their impact on the mixing properties of the Markov chains they generate. Examples are provided to illustrate the different perturbations explored. Furthermore, we delve into the analysis of a discrete Markov chain that is based on the Frechet family of copulas. The objective of this study is to explore the impact of discrete marginals on copula-based Markov chains. We analyze the mixing properties of such models to emphasize the difference between …

Essays On The Greek Debt Crisis And The Welfare Paradox In The Lucas Natural Rate Model, Liandong Yang

Electronic Theses and Dissertations

This dissertation includes two projects, one on the Greek debt crisis and the other on the welfare in the Lucas natural rate model.

The first chapter discusses the origin of Greek debt crisis. The Greek debt crisis stands out as a compelling case study of a severe financial crisis in a developed country within a currency zone. Despite the abundance of literature on the subject, the significance of debt accumulation in the 1980s is often overlooked, and details are frequently omitted. Through an analysis of data gathered from Greek government’s public finance statistical yearbooks spanning from 1962 to 2008, I …

Il-17a Inhibitors For The Treatment Of Psoriasis, Mangesh Bankhele

Electronic Theses and Dissertations

Psoriasis is a long-lasting skin condition caused by the immune system, which is characterized by red, scaly areas. It mainly affects the scalp, elbows, knees, and lower back. Psoriasis, which affects around 2-3% of the world's population, has a substantial influence on the quality of life of people who suffer from it. The disorder arises due to an atypical immunological response in which the immune system mistakenly attacks skin cells, causing fast cell reproduction, inflammation, and excessive growth. Psoriasis can be treated with topical therapies, systemic drugs, and biologics. Topical therapies, including corticosteroids, vitamin D analogs, and retinoids, are commonly …

Designing Ris-Assisted Uav 3d Trajectory Using Deep Reinforcement Learning, Linsong Li

Electronic Theses and Dissertations

Unmanned aerial vehicles (UAVs) are increasingly employed as temporary base stations or access points to facilitate data transfer between ground terminals (GTs). However, in urban environments, UAV-GT communication links often face challenges due to obstructions from buildings and other obstacles, resulting in reduced data transfer efficiency. Reconfigurable intelligent surfaces (RIS) provide a promising solution by reflecting signals to enhance communication quality between UAVs and GTs. This thesis addresses the critical challenge of responsive UAV trajectory optimization in RIS-assisted communication networks. A novel approach is proposed, integrating federated learning with reinforcement learning techniques, specifically Double Deep Q-Network (DDQN) and Deep Deterministic …

Formulation And Characterization Of Clotrimazole Buccal Films Using Hot Melt Extrusion, Harish Kandhuri

Electronic Theses and Dissertations

Clotrimazole is a broad-spectrum antifungal /antimycotic, it is used topically in the treatment of oropharyngeal candidiasis. The oral route is the most preferred route of administration 60% of the conventional dosage forms are available as tablets and capsules. The main objective of the study was to develop and Formulate Clotrimazole oral film to get local effect for treating oropharyngeal candidiasis. Oral films are thin flexible strips which can be placed on the tongue, where it adheres to the surface of the tongue and dissolves releasing the drug into the oral cavity. Here, the films are formulated using hot melt extrusion …

The Trading Dynamics Of Corporate Bonds And Bond Etfs, Cindy Pan

Electronic Theses and Dissertations

We find trading dynamics in bond ETFs and equity ETFs to be different. Although lit trading activity in equity ETFs is greater than bond ETFs, hidden liquidity in bond ETFs is significantly higher than in equity ETFs. Dark trading volume in bond ETFs is also greater than dark trading volume in equity ETFs. Results are robust to an out-of-sample test and is not driven by a specific exchange or specific types of bond ETFs. The extensive use of hidden and dark liquidity for bond ETFs relative to equity ETFs indicates that demand for opaquely trading bond ETFs has value to …

Radiation And Scattering Of Electromagnetic Waves With The Use Of Metasurface Cloaks In Printed Antenna Technology, Shefali Pawar

Electronic Theses and Dissertations

It is a well-known fact that antennas form the very core of the modern wireless communication systems. As such, an escalating demand for increase in the wireless system capacity compels and necessitates accommodation of densely packed antennas in a very compact space. However, a practical design of such dense antenna systems may not only be cumbersome but could also lead to the deterioration of the overall system performance, considering the fact that such a system may suffer from destructive interference, owing to the cross-coupling between the antenna elements jammed together. In this regard, we endeavor to curb the detrimental effects …

Juvenile Coping And General Strain Theory, Peyton Conner Stephenson

Electronic Theses and Dissertations

The purpose of this study is to quantitatively assess the impact of victimization on behavioral and emotional outcomes among a sample of adolescents detained within the juvenile justice system. Specifically, the study focuses on understanding the relationship between reports of victimization (e.g., being beaten up or threatened) and maladaptive coping mechanisms, such as involvement in fighting. To do so, Agnew’s (1992) General Strain Theory (GST) and the Pains of Imprisonment are adopted as frameworks for understanding the role of strain or stressors in prompting deviant behavior as a coping mechanism. This study uses secondary data from the Northwestern Juvenile Project …

Motivation And Attitudes Toward Learning English As A Foreign Language: A Case Study Of Urban And Rural University Freshmen In Saudi Arabia, Munif Almasarir

Electronic Theses and Dissertations

The Saudi educational system faces several challenges that contribute to low proficiency in English among Saudi students. Previous studies have focused on the EFL curriculum and pedagogical challenges, but there is a lack of research specifically examining other main psychosocial factors that contribute to the attainment of English proficiency. Motivational and attitudinal factors have been proven to have an impact on the proficiency level among EFL students. My study investigates the perceived influence of geographical location on students' attitudes and motivation toward English as a global language in Saudi Arabia. By utilizing an ethnographic approach focusing on both rural and …

Grace Satellite Spatial Resolution Downscaling Using Machine Learning: Methods And Applications, Abdel Rahman M. Awawdeh

Electronic Theses and Dissertations

The Gravity Recovery and Climate Experiment (GRACE) satellite mission has been instrumental in advancing our understanding of global water dynamics, providing unprecedented insights into terrestrial water storage (TWS). Despite its revolutionary contributions, the coarse spatial resolution of GRACE data (~300 km² grids) limits its utility for local-scale water resource management, particularly in regions requiring detailed hydrological analysis such as the Mississippi Delta. This dissertation addresses this limitation by developing and validating machine learning models to enhance the spatial resolution of GRACE data, thereby facilitating more precise and effective local water management strategies.

This research first establishes a comprehensive background in …

Developing And Validating A Novel Screening Instrument For General Psychological Distress, Steven M. Bishop

Electronic Theses and Dissertations

This study presents the results of both factor analyses in developing the General Psychological Distress Screener (GPDS), and provides preliminary data of its predictive validity. As a new screening instrument, the GPDS assesses mental fatigue and emotional distress in adults and predicts certain psychiatric disorder diagnoses. Drawing upon network analysis principles, two studies were conducted to construct and refine the GPDS. Study 1 identified the variable constructs from psychopathology networks that were used in Study 2. Study 2 used principal axis factoring to develop a 4-factor solution, which was subsequently reduced to a 2-factor model for improved interpretability. Confirmatory Factor …

The Effects Of Technology-Enhanced Learning On Radiologic Sciences Student Engagement, Zack Gray

Electronic Theses and Dissertations

This dissertation investigates the multifaceted connection between technology-enhanced learning (TEL) and student engagement, with a specific emphasis on student perceptions, attitudes, and distractions associated with technology usage in the classroom. Recognizing the increasing prevalence of technology in educational settings, this study seeks to understand how students perceive technology in the learning environment and how these perceptions influence their attitudes toward its use. The research framework is anchored in the Theory of Planned Behavior (TPB), providing a theoretical lens to assess the cognitive factors influencing student behavior.The study employs a mixed-methods approach, combining surveys and observations to gather comprehensive insights into …

Increasing Minority Student Enrollment: An Applied Research Study On Increasing The Enrollment Of Minority Students In Advanced Placement Courses, Tamekia Helm

Electronic Theses and Dissertations

Addressing the disparity in Advanced Placement (AP) course enrollment among minority students at Greater High School is the focus of this research. Through an extensive review of the literature, the study examines the various factors contributing to this gap, including access limitations and systemic barriers. Additionally, teacher perceptions, student attitudes, and parental involvement are explored to understand the influence on AP course enrollment decisions. Utilizing a mixed-methods approach, including surveys and interviews, data is collected from students, teachers and parents to gain comprehensive insights.

Proposed solutions to enhance AP course enrollment include targeted outreach initiatives and support for minority students. …

Weak Disorder Limit On Diamond Hierarchical Graphs With Vertex Disorder In The Critical Case, Casey Reid Lochridge

Electronic Theses and Dissertations

We compare three models for a directed polymer in a random environment (DPRE): the rectangular lattice, the branching lattice, and the diamond hierarchical lattice. Our focus is primarily on the diamond model, in which the polymers traverse a recursively defined diamond graph with a random environment composed of random variables indexed by the vertex set. The diamond graphs are constructed iteratively according to a given branching parameter b ∈ {2, 3, 4, . . .} and segmenting parameter s ∈ {2, 3, 4, . . .}, and our main result concerns the critical case b = s. In this case, …

Enhancing Flex Student Success: Factors Influencing Achievement In The Istudy Program At The University Of Mississippi, Jennifer Jewel Sanford

Electronic Theses and Dissertations

Higher education institutions have recently increased the number of online courses offered to students. A need exists to understand student success within asynchronous self-paced online education programs. This study explores the factors that impact student success in the Independent Study Program (iStudy) at the University of Mississippi, focusing specifically on Flex (Full-Year) enrolled students. Student success is defined as achieving a completion grade of "C" or higher. The proposed study utilizes a mixed-methods approach, combining quantitative analysis of student performance data with qualitative feedback from student performance data and exit surveys. The assessment aims to provide a comprehensive understanding of …

Improving American Learners’ Pronunciation Of Arabic Pharyngeals: Traditional Vs. Tbi Method, Yasmine Sedeek

Electronic Theses and Dissertations

Mastering the phonological aspects of a second language (L2) poses significant challenges for adult learners, often affecting their intelligibility in acquiring that language (Derwing, Munro, & Wiebe, 1998). McAllister (1997) has highlighted L2 learners’ struggles in perceiving and producing novel segmental features, which is corroborated by The Perceptual Assimilation Model of L2 speech learning (PAM-L2) proposed by Best & Tyler (2007), which posits that the perception of L2 phonetics is a critical precursor to their accurate production. Against this backdrop, the present study aims to improve the intelligibility of Arabic pharyngeals (/ʕ/ and /ħ/) among English-speaking learners studying Arabic as …

Investment Decisions Of Institutional Investors, Sunghan Bae

Electronic Theses and Dissertations

In the first essay, we investigate whether social preference affects institutional investors’ socially responsible investing (SRI) by examining US insurance firms. Prior literature suggests that investors value firms’ socially responsible endeavors and are willing to sacrifice financial gains when conducting SRI. We show that, on average, insurers allocate less weight to securities with high ESG (Environment, Social, and Governance) scores. However, a subset of insurers with high Corporate Social Responsibility (CSR) scores overweight high ESG securities. Moreover, we find that insurers with high CSR scores experience positive abnormal returns when they invest in high ESG stocks. This indicates that insurers …

Indirect And Direct Pathways Of Migratory Shorebird Effects On Nitrogen Cycling Within Temporarily Flooded Agricultural Fields, Victoria Blocker

Electronic Theses and Dissertations

The global human population continues to grow exponentially, and agriculture will need to become more productive to meet growing food demands. Humans also need clean water and other services that ecosystems provide. This requires future agriculture production to reduce environmental and wildlife impacts through improved efficiencies and best management practices. Migratory shorebirds rely on wetlands throughout North and South America as stopover habitat for rest and refueling during migration. Temporarily flooded farmlands in the Mississippi Delta have proven to be beneficial locations for shorebirds during migrations along the central flyway. This conservation practice also enhances wetland properties that promote excess …