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Loralee Clark, Loralee Clark, Loralee Clark

Virginia Poets Database: A Literary and Educational Resource

No abstract provided.

Glioma Segmentation In Mri Using A 3d Hybrid U-Net With Adaptive Self-Attention And Multi-Modal Fusion, Evan P. Savaria

Computer Science Theses & Dissertations

Accurate glioma segmentation from multi-modal Magnetic Resonance Imaging (MRI) is essential for diagnosis, treatment planning, surgical guidance, radiation targeting, and longitudinal monitoring. MRI modalities such as T1, T1Gd, T2, and FLAIR provide complementary information for identifying clinically important tumor sub-regions, including enhancing tumor (ET), tumor core (TC), and whole tumor (WT). However, many existing segmentation methods do not fully preserve modality-specific information, process all modalities and slices uniformly, and often rely on a single shared fusion strategy for all sub-regions. These limitations can reduce segmentation accuracy, increase computational cost, and limit clinical interpretability.

This dissertation addresses these challenges through three …

Simulations Of Inverse Compton Scattering With Radiation Reaction, Elizabeth Breen-Lee

Physics Theses & Dissertations

Inverse Compton scattering (ICS) is a versatile mechanism for producing bright, tunable, and quasi-monochromatic x-ray and gamma-ray radiation through the interaction of relativistic electrons with intense laser pulses. These sources have applications spanning medicine, archaeological studies, materials science, and fundamental research, motivating continued efforts to improve both their performance and the accuracy of theoretical models used to describe them. As nextgeneration laser and accelerator facilities continue to reach increasingly intense regimes, efficient and accurate simulation techniques have become essential for the design and optimization of ICS sources. This dissertation presents the development of analytical and computational methods for modeling inverse …

Autistic Students' Experiences With Hybrid Flexible Instruction In Higher Education: An Interpretive Phenomenological Study, Tracey Nicole Barr

STEMPS Theses & Dissertations

During the twenty-first century, autistic learners have enrolled in colleges and universities in greater numbers; however, the majority of research focused on their experiences in higher education has found them to be less academically successful than their neurotypical peers. The academic skills that autistic students bring to higher education are often tempered by social, emotional, and self-regulative challenges. The body of research focusing on autistic learners’ experiences in higher education is currently limited and focused primarily on fully in-person and online course models. No extant research has focused on autistic students’ experiences with hybrid or blended course models.

This interpretive …

Parameter Dependent Chen-Fliess Series And Their Nonrecursive Interconnections, Natalie T. Pham

Electrical & Computer Engineering Theses & Dissertations

In control theory, a Chen-Fliess functional series is a weighted sum of iterated integrals constructed from a given set of input functions. Such series can be used to represent nonlinear input-output systems. In applications, they have been employed to characterize interconnected nonlinear systems, to solve system inversion and tracking problems, and to design predictive and adaptive controllers.

Distributed parameter systems exhibit spatial dependence along with temporal dependence. Such systems are typically represented in terms of partial differential equations. In control theory, there appears to be no existing method for representing the input-output map of a distributed system via a Chen-Fliess …

Menopausal Symptoms, Psychosocial Factors, And Physical Activity Among Physically Active Midlife Females, Ella Onsoriasl

Exercise Science Theses & Dissertations

Menopausal symptoms are common during midlife and may be associated with females' physical activity (PA) participation, yet how these symptoms relate to PA levels, perceived confidence and enjoyment, and psychosocial resources such as social support (SS), exercise identity, and quality of life (QOL) remains unclear. The purpose of this study was to examine how menopausal symptom severity relates to PA levels, perceived confidence and enjoyment during PA, and psychosocial factors, including SS, exercise identity, and QOL. This cross-sectional study surveyed 151 midlife females aged 40 to 60 who reported engaging in intentional PA at least once per week. Participants completed …

The Effects Of Working With Unidentified Migrant Remains: Caregiving, Border Security, And Human Rights On The U.S.–Mexico Border, Jennifer Delaine Huddleston

Graduate Program in International Studies Theses & Dissertations

This dissertation explores how migrant death and the handling of unidentified remains operate within U.S. border governance, focusing on caregivers, forensic anthropologists, and volunteer search-and-recovery teams who recover, document, and try to identify the dead along the U.S.–Mexico border. Using classic grounded theory and reflexive visual ethnography, the study includes interviews, field observations, and documentary photography conducted in South Texas, covering Brooks, Maverick, and Webb Counties.

Instead of viewing migrant deaths as accidental humanitarian tragedies, this dissertation situates caregivers’ daily work within a historical trajectory of deterrence-based border policies, from Prevention Through Deterrence to modern state-led enforcement regimes. It demonstrates …

A Longitudinal Analysis Of Hospital Consumer Evaluation In Virginia, Tulay Akmandor Inac

Health Services Research Dissertations

Suboptimal patient experience signals a need to improve clinical efficacy, patient safety, and healthcare quality. The COVID-19 pandemic intensified hospital resource and staffing demands, reducing hospitals’ capacity to invest in patient experience improvement. Prior studies remain limited because many lack longitudinal structure and organized theoretical models, making temporal inference difficult and weakening analyses of patient experience disparities. To address these limitations, this dissertation incorporates three studies examining patient experience and pandemic-related effects.

In state-level markets comparable to Virginia, limited research has examined longitudinal patient experience trends across regional hospital systems using HCAHPS scores. The first study uses descriptive trend analysis …

A Qualitative Case Study Of Leadership Development In A Graduate Medical Laboratory Science Program, Demetra Castillo

EVMS School of Health Professions Theses & Dissertations

Leadership development is increasingly recognized as an essential component of healthcare education, particularly as medical laboratory professionals assume expanded responsibilities involving collaboration, decision-making, systems thinking, and organizational leadership. Despite this need, limited research has explored how leadership develops within graduate medical laboratory science (MLS) programs. This qualitative case study examined leadership development through the lens of Experiential Learning Theory (ELT). Two research questions explored how the program fostered leadership development through students’ professional biographies, leadership questionnaires, final reflection papers, and leadership credos and how leadership reflections demonstrated growth over time. Secondary data from five student cases were analyzed using deductive …

Energy Transition In Africa: A Comparative Analysis Of Five African Countries, Boluwatife G. Ayankojo

Graduate Program in International Studies Theses & Dissertations

Global energy transition remains a critical challenge for reducing carbon emissions and protecting the environment, with solar energy adoption driving improvements in both energy efficiency and conservation. This research focuses on Africa's transition from fossil fuels to solar energy. As population growth and blackouts increase, African countries must transition from unreliable, centralized national grids to decentralized, low-carbon alternatives that ensure quality household electricity. While some countries have advanced in this transition to sustainable solar energy, others lag behind. The limited access to electricity hinders the African continent's healthcare, education, economic growth, and mortality rates. This research establishes the importance of …

Atomic-Scale Investigation Of Functional Molecular Systems And Graphene Nanoribbons Using Scanning Probe Microscopy, A.M. Shashika D. Wijerathna

Physics Theses & Dissertations

Emerging molecular electronics, molecular devices, and carbon-based nanotechnologies increasingly rely on the precise control of molecular structures and interfaces at the atomic scale. Advancing these systems requires experimental techniques capable of resolving atomic structures, quantifying molecular behavior, and revealing the mechanisms governing nanoscale assembly. Scanning probe microscopy uniquely provides these capabilities by combining atomic-resolution imaging with local spectroscopy and manipulation. This dissertation employs ultra-high-vacuum low-temperature scanning tunneling microscopy (UHV-LT-STM) and qPlus atomic force microscopy (qPlus AFM) to address three complementary challenges: (i) atomic-scale characterization of complex supramolecular architectures, (ii) quantitative investigation of mechanically induced conformational switching of individual molecules, and …

Towards More Realistic And Practical Graph Backdoor Attacks, Jiawei Chen

Computer Science Theses & Dissertations

Graph Neural Networks (GNNs) have demonstrated remarkable performance on graph-based learning tasks and are increasingly deployed in security-critical applications. However, recent studies have shown that they are highly vulnerable to graph backdoor attacks (GBAs), where adversaries implant malicious triggers to induce targeted misclassification during inference. Despite their effectiveness, existing GBAs are often developed under unrealistic assumptions, such as focusing exclusively on simple homogeneous graphs or assuming the adversary possesses privileged access to target nodes during inference. This dissertation aims to systematically investigate and design graph backdoor attacks under significantly more realistic graph settings and adversarial constraints.

First, we investigate the …

The Mediating Role Of Hope In The Relationship Between Everyday Discrimination And Depression Among College Students, Busra Vurkun

Counseling & Human Services Theses & Dissertations

Research shows that marginalized populations experience disproportionately higher psychological distress (Budhwani et al., 2015; Bailey et al., 2019). Everyday discrimination, defined as chronic interpersonal mistreatment such as microaggressions and disrespect, is associated with greater depression and lower psychological well-being (Essed, 1991; Calabrese et al., 2015). Although the negative effects of discrimination are well established, less is known about protective factors that may reduce these outcomes. One such factor is hope, conceptualized by Snyder et al. (1991) as agency thinking and pathways thinking and linked to lower depression and greater resilience (Arnau et al., 2007; Banks et al., 2008). This study …

Empirical Rhetorical Modeling: New Analytical Tools To Evaluate The Intensity Of Rhetoric, August Immel

English Theses & Dissertations

Since 2020, the United States has experienced a surge of incendiary rhetoric in contemporary political discourse, which exacerbates societal polarization and incites violence as evidenced by heightened politically motivated attacks. Numerous actors characterize the impetus of such violence as “extreme rhetoric.” No standard definition exists for such a term, and this gap necessitates the central research question of this dissertation, which interrogates how rhetoric can be systematically evaluated for “extremeness.” I propose that the issue of extreme rhetoric can be fruitfully examined from within the context of rhetorical theory, but instead of attempting to create a new definition of “extreme …

De Facto Captivity In The Land Of The Free: Exploring The Confining Effects Of Network And System Avoidance, Brianna Ovalle

Sociology & Criminal Justice Theses & Dissertations

Encroaching state surveillance has primarily targeted people of color living in urban, inner cities, resulting in both much higher likelihoods of encountering state agents and the consequences of such contact. The ceaseless surveillance has led some individuals to engage in protective behaviors aimed at minimizing encounters with agents of the CLS. These behaviors are adaptable to present risks of surveillance and contact with the system. While there are various types of avoidance, the focus of this research is system avoidance and network avoidance. Previous literature for both types of avoidance focuses on the experiences of lower SES men. Further, as …

Exploring The Determinants Of User Discontinuance In Ai-Driven Usage-Based Insurance, Wenzhuo Li

Theses and Dissertations in Business Administration

While interest in algorithmic decision-making continues to grow, limited research has examined the post-adoption phase. This study examines how users evaluate their post-adoption experiences with algorithmic decision-making in the context of usage-based insurance (UBI), focusing on how expectation disconfirmation shapes satisfaction and the intention to discontinue use. It explores two key questions: What factors influence users’ discontinuance intention toward AI-based UBI systems? And how do specific algorithmic characteristics alter how users form these post-adoption evaluations? To investigate these questions, this study develops a comprehensive theoretical model that integrates the Expectation Confirmation Model and Reactance Theory, incorporating additional factors such as …

Drinking Group Injunctive Norms: An Event-Level Examination, Karolina Kazlauskaite

Psychology Theses & Dissertations

College students are at increased risk for negative alcohol-related outcomes. Theoretical and empirical support suggest that peer groups play a crucial role in college student alcohol use, in part because they establish normative values and behaviors (i.e., norms) that members follow. Research indicates that those who identify more strongly with a group are more likely to embody that group’s values—particularly regarding drinking. Notably, injunctive norms, or perceptions of peer permissibility toward drinking, predict individual drinking outcomes, such that perceiving one’s peers as more approving confers additional risk for personal drinking. However, prior examinations of injunctive norms have not assessed perceptions …

Time-Frequency Analysis Of Arterial Pulse Signals Of Cardiovascular Disease Patients Measured By A Microfluidic-Based Tactile Sensor, Md Mahfuzur Rahman

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation presents a single-degree-of-freedom (SDOF) based time–frequency analysis framework that can simultaneously extract a comprehensive set of cardiovascular autonomic indices from arterial pulse wave recordings obtained at rest and post-exercise, supporting non-invasive monitoring of autonomic recovery during cardiac rehabilitation. The framework rests on three technical contributions.

First, an SDOF analytical model of motion artefacts quantifies two physically distinct distortion mechanisms: additive baseline drift and Time-Varying System Parameter (TVSP) generated distortion of the Tissue-Contact-Sensor (TCS) stack. Baseline drift is slowly varying and removable by filtering; TVSP distortion rides on all harmonics of the true pulse signal and cannot be removed …

Proxy Interfaces For Enhancing Non-Visual Web Usability, Md Javedul Ferdous

Computer Science Theses & Dissertations

People with blindness or visual impairments (BVI) face significant barriers when navigating the web, even when digital content is technically accessible. These challenges arise not from a lack of access, but from a mismatch between vision-centric user interfaces and the linear, audio-based interaction paradigms of screen readers. Sighted users rely on spatial layout, grouping, and visual cues to interpret structure quickly, while blind users must explore elements sequentially, often without sufficient context. As a result, they expend greater cognitive effort, become disoriented more easily, and struggle with tasks that are usually trivial for sighted users. Although accessibility initiatives have focused …

Deep Multimodal Sensor Fusion For Autonomous Driving: A Real-World Deployment On Little Blue, Raphael T. Pamie-George

Electrical & Computer Engineering Theses & Dissertations

Accurate perception and control systems are essential for autonomous vehicles to safely interpret and navigate complex environments. Individual sensing modalities such as cameras, LiDAR, and inertial measurement units (IMUs) provide valuable environmental and vehicle state information; however, each sensor exhibits inherent limitations when used independently. Camera performance can degrade under varying lighting conditions, LiDAR measurements may be sparse or affected by environmental noise, and IMU measurements are susceptible to drift over time. Little Blue, a research autonomous vehicle platform from ODU (Old Dominion University), previously relied primarily on camera-based data for neural network training, limiting the system’s ability to exploit …

The Association Between Prenatal Nicotine Exposure And Postpartum Depression, Reem Ali Sharaf-Alddin

Health Services Research Dissertations

Postpartum Depression (PPD) is the most common mental health complication of childbirth with 17% of women globally and 13% in the US experience PPD. The pathophysiology of PPD is not yet fully understood, with psycho-social, biological, and environmental factors, interplaying together and predisposing to PPD. One key modifiable risk factor is prenatal exposure to nicotine (PEN) including Active Tobacco Smoking (ATS), Secondhand Smoking (SHS), and Electronic Nicotine Products (ENPs). Several studies investigated the association between prenatal ATS or SHS and PPD, however the findings were inconclusive. There is a lack of studies that assessed the overall PEN, and none of …

Macroscopic Classical And Quantum Models Of Inverse Compton Scattering, Emerson Penn Rogers

Physics Theses & Dissertations

Inverse Compton sources — in which a relativistic electron beam scatters a laser pulse to produce tunable, collimated, high-energy radiation—have emerged as among the most promising compact radiation sources, with applications ranging from nuclear photonics to medical and nanoscale imaging and metrology. The most viable current tabletop configuration couples laser-wakefield acceleration with inverse Compton scattering, producing GeV-scale electron beams over millimeter distances. As laser intensities increase and electron energies grow, the interaction enters the radiation reaction regime, where the energy radiated by the electron becomes a significant fraction of its kinetic energy. Predicting the scattered electron energy spectrum — the …

The Role Of Phenotypic Plasticity And Bet-Hedging In Coping With Unpredictable Temperature Fluctuations In The Marine Annelid Ophryotrocha Labronica, Gabrielle Dawn Newton

Biological Sciences Theses & Dissertations

Coastal ecosystems are increasingly exposed to unpredictable temperature fluctuations, potentially favoring strategies that buffer populations against environmental uncertainty. This study examines how phenotypic plasticity and diversified bet-hedging contribute to variation in life-history traits under differing thermal predictability in the marine annelid Ophryotrocha labronica. After three generations at 24 °C, broods were reared for three generations under four thermal regimes: constant 24 °C (C24), constant 27 °C (C27), predictable fluctuations (Fp), and unpredictable fluctuations (Fu). Survival was assessed before and after acclimation to evaluate selective pressure among regimes. Age at maturity, fecundity, and growth rate were used to quantify plasticity (trait …

Two Essays On Designing Conversational Agents: Varying Level Of Mimicry And Personality–Brand Congruence, Sama Ashouri

Theses and Dissertations in Business Administration

Across two essays, this dissertation demonstrates that mimicry and personality shape consumers’ perceptions of chatbot intelligence, creativity, and fit, with downstream effects on recommendation acceptance that depend on factors such as mimicry intensity, brand familiarity.

Essay1: Mimicry, a central aspect of human interaction, is increasingly being examined in human–AI communication, particularly with chatbots. While prior research shows mimicry can build rapport, trust, and engagement, it has often been treated as a binary factor, overlooking how different levels may influence user perceptions. This research proposes and tests a dual-mediation framework in which different levels of chatbot mimicry affects recommendation acceptance through …

Modeling And Generating Crash Avoidance Behaviors In Safety-Critical Vehicle–Pedestrian Interactions Using Deep Reinforcement Learning, Qingwen Pu

Civil & Environmental Engineering Theses & Dissertations

Traffic crashes between vehicles and pedestrians arise from complex, split-second interactions in which both parties make rapid evasive decisions. Four fundamental gaps persist in existing research. Surrogate safety measures assume linear trajectories, failing to capture the curved movements of turning vehicles and crossing pedestrians at intersections. Single-agent modeling treats one party as a fixed obstacle, ignoring the joint decision-making that governs near-miss outcomes. The effect of vehicle type on pedestrian avoidance behavior—whether pedestrians respond differently to automated vehicles (AVs) than to human-driven vehicles (HDVs)—remains poorly understood. Finally, automated driving system development is hampered by a severe scarcity of large-scale, behaviorally …

Structure Meets Context: A Simulation Study Of Centralized And Decentralized Decision-Making In Complex Environments, Murat Balci

Engineering Management & Systems Engineering Theses & Dissertations

The question of when to centralize or decentralize decision-making authority is a foundational problem in organizational theory and management science. Yet existing research often favors decentralized structures, frequently treating them as universally superior, and provides limited guidance on when centralization may be more effective. Leaning toward decentralization without thoroughly exploring options leaves organizational designers without clear direction under varying environmental conditions. This study addresses that gap by developing and applying a simulation-based framework to evaluate the context-dependent effectiveness of centralized and decentralized decision-making structures.

Drawing on contingency theory and decision science, the study conceptualizes environmental complexity along two dimensions: dynamism …

Multi-Particle Reactions In Lattice Field Theories: From Euclidean To Quantum Computations, Marco Antonio Carrillo Bernal

Physics Theses & Dissertations

Amplitudes of multi-particle processes provide a probe of the dynamics described by relativistic quantum field theories. In the context of quantum chromodynamics, these amplitudes encode the way in which quarks and gluons are bound together by the strong nuclear force to form hadrons and govern their interactions. The non-perturbative nature of the strong interactions complicates the study of hadronic amplitudes from first principles. The most effective way of studying hadronic reactions non-perturbatively is the numerical framework known as lattice quantum chromodynamics. This method relies on theoretical formalisms that establish relations between numerical observables, such as finite-volume energy levels and matrix …

Physiological, Cognitive, Behavioral, And Perceptual Contributors To Falls Risk Across Middle And Older Adulthood, Jacquelyn Moxey

Rehabilitation Sciences Theses & Dissertations

Falls are multifactorial events influenced by physiological, cognitive, behavioral, and perceptual factors. Although falls prevention research has traditionally focused on older adults and objectively measured physical impairments, less is known about how cognitive performance, physical activity, and perceptions of ability collectively contribute to falls risk vulnerability across middle and older adulthood. This dissertation examined these relationships through three complementary studies.

Study 1 examined associations between cognitive screening performance and physiological falls risk in 315 community-dwelling older adults. Lower global cognitive performance was associated with greater physiological falls risk. Performance on items reflecting attention and visuospatial/executive function demonstrated the strongest domain-level …

Motivation And Constraints In Recreation Participation Among Children And Adults With Disabilities, Monica Klock

Human Movement Studies & Special Education Theses & Dissertations

This dissertation investigated how motivation and constraints relate to participation in outdoor and community recreation among children with disabilities and adults who are blind or visually impaired. Although outdoor recreation is associated with important physical, psychological, and social benefits, people with disabilities continue to participate at lower rates than their peers without disabilities, and prior work shows that barriers extend well beyond physical access to include structural, interpersonal, and intrapersonal constraints. Drawing on the Constraint–Negotiation Model (CNM) and social cognitive theory, this dissertation addressed gaps in multivariate research and life-course perspectives by examining whether and how motivations, perceived constraints, and …

Quantitative Surface-Enhanced Raman Spectroscopy For Antiretroviral Drug Monitoring: Novel Quality Index And Distributional Approaches In Aqueous And Plasma Matrices, Marguerite Rose Butler

Chemistry & Biochemistry Theses & Dissertations

Surface-enhanced Raman spectroscopy (SERS) offers high sensitivity for molecular detection but is limited for quantitative applications by spatial heterogeneity in signal enhancement on dried colloidal substrates. This Dissertation addresses these limitations through the development and evaluation of novel quantitative methods applied to the antiretroviral drugs tenofovir and emtricitabine.

A quality index (Qi) metric was developed to rank individual SERS spectra within each well based on analyte peak prominence relative to local baseline. SERS spectra were acquired from evaporated silver colloid deposits on aluminum well plates using a custom raster-scanning Raman system. Calibration curves were constructed using the top-ranked spectra (Top-Qi …