Digital Commons Network^™

Wind-Induced Gravel Blow-Off: Experimental Investigations And Predictive Modeling For Resilient Roof Design, Md Safwan Ahsanullah

All Dissertations

Roof gravel blow-off during severe windstorms is a major hazard, leading to roof damage and significant downwind impacts. Understanding the initiation mechanisms for gravel blow-off is critical for improving building design and mitigating windborne debris risks. Existing experimental data on the wind speed required to initiate gravel blow-off have been collected from high-speed, full-scale tests at wind tunnels. While these tests form the basis of current design guidelines, they are expensive and can lack generalizability. As a result, rooftop gravel is frequently blown off at wind speeds below the design thresholds. This dissertation investigates the onset of rooftop gravel motion, …

User Acceptance Of Shared Autonomous Vehicles, Haotian Su

All Dissertations

A dissertation is proposed to explore user acceptance of shared autonomous vehicles (SAVs). SAVs are facing limited user acceptance. To systematically tackle the user acceptance barriers of SAVs, the main problem can be disintegrated into two sub-problems of user acceptance of autonomous vehicles (AVs) and ridesharing. The comfort of the ride experience in AVs is a determinant of user acceptance. Understanding the influential factors and developing methodologies to quantify human comfort in AVs are essential to facilitating future research to improve human comfort in AVs. The current pooled rideshare (PR) service closely resembles the anticipated future of SAVs. Understanding why …

Understanding The Role Of Ligamentous Constraint In Trapeziometacarpal Pathomechanics, Lizzie Walker

All Dissertations

The trapeziometacarpal (TMC) joint is the most common site for osteoarthritis (OA) in the upper limb. This joint is characterized by its wide range of motion and limited bony stability, making it susceptible to OA. The TMC joint relies mostly on ligaments and muscles for its static and dynamic stability, respectively. While importance of both volar and dorsal capsular TMC stabilizers has been demonstrated, the role of TMC ligamentous tissues in the development of thumb basal joint OA remains unclear.

The goal of this work was to identify morphometric and mechanical changes in key TMC ligament stabilizers, including the volar …

The Effects Of Cigarette Smoke Extract On Osteoarthritis In A Primary Joint Tissue Explant Model, Emily Sawvell

All Dissertations

Osteoarthritis (OA) is the most common degenerative joint disease in the world with an economic burden of nearly $140 billion annually. Factors identified to increase the risk of developing OA include age, obesity, sex, race, genetics, and previous joint injury. However, one risk factor that has been scarcely studied in OA etiology is cigarette smoking. While some studies have reported smoking to protect against OA, increasing evidence suggests that cigarette smoking results in more severe and painful OA, increases the rate of developing OA, and reduces the efficacy of pain medications and arthritis-targeting therapies. Despite this, the impact of cigarette …

Grid Forming Inverters For Microgrid Operation Enhancement, Jan Westman

All Dissertations

Modern electric power systems are confronted with several major challenges including the increasing frequency and severity of weather events, aging infrastructure, high material costs, cyber-attacks, and substantial delays in global supply chains. Microgrids provide a solution to these challenges by insulating customers from the power outages occurring in their local distribution system. A microgrid is a small independent power system with its own power generation and energy storage resources that can supply customers’ electricity needs. When an outage occurs, a circuit breaker will disconnect the microgrid from the distribution system. Successful operation of the microgrid requires one or more devices …

Integrating Applied History And Artificial Intelligence (Ai) Into City Planning Practice, Russell H. Stall

All Dissertations

History matters. History provides a vital foundation for shaping present decisions and future planning. By understanding a city’s past, cities can make more thoughtful, informed choices to guide development and policy with greater intention and impact.

Greenville, South Carolina, is a unique city planning case study and learning laboratory. Greenville’s Downtown revitalization since the 1980s demonstrates how historical insights can be integrated into contemporary policymaking to create vibrant, human-centered, and citizen-focused urban environments. Greenville’s evolution from a deserted, forgotten Main Street to one of the world’s most livable cities is an example of community development worthy of emulation from other …

Exploring The Pedagogical Impact Of Software Development Live Streams: Informal Learning Opportunities For Software And Game Developers, Ella Kokinda

All Dissertations

Live streaming is an increasingly popular medium for throwing back the curtain on software development where streamers and viewers share their knowledge and experiences. Popular platforms like Twitch and YouTube enable developers to stream live coding sessions where people around the world can engage in real-time collaboration, feedback, knowledge sharing, and skill development. This work investigates the pedagogical implications and learning opportunities present in software and game development live streaming while focusing on the role of streaming as a learning environment and collaborative community. We begin by exploring summer camps as an informal learning opportunity for STEM education, highlighting the …

Countering Deficit Narratives Through A Blackcrit Lens By Examining Case Studies Of Black College Mathematics Students’ Classroom Experiences, Akhenaton Wilbourn

All Dissertations

This dissertation examines the lived experiences of 11 Black college mathematics students at their predominantly white institution (PWI) through the lens of Black Critical Theory (BlackCrit) to counter deficit narratives about the racial achievement gap (RAG) in mathematics education courses. Deficit narratives often attribute disparities between Black and white students’ mathematical performance to assumed deficiencies in Black students’ abilities rather than systemic inequities, historical marginalization, and ongoing anti-Blackness in educational settings (Cobb & Russell, 2015; Kress, 2021). Using multiple case studies, this study explores how anti-Blackness manifests in mathematics classrooms, how students navigate tensions between multiculturalism, neoliberal educational policies, and …

Deciphering And Translating Bioinspired Structures For Engineering Materials Design Via Computational Modeling And Machine Learning, Zhangke Yang

All Dissertations

Nature has evolved extraordinary structural materials—such as nacre, bone, and the mantis shrimp’s dactyl club—that achieve remarkable combinations of strength, toughness, and impact resistance. These properties arise from sophisticated synergies between structure and composition. Inspired by these biological systems, this dissertation presents a comprehensive investigation into bioinspired materials, uncovering fundamental mechanisms and providing guidance on designing materials with superior mechanical properties.

This dissertation begins by examining the "brick-and-mortar" structure of nacre, which informs the design of layered polymer-graphene nanocomposite films. Using coarse-grained molecular dynamics simulations, I elucidate mechanisms of dynamic wave propagation and energy dissipation in these systems, providing critical …

Real-Time Active Thermal Management And Degradation Forecasting Of Power Electronics Building Blocks In All-Electric Ships, Ali Moghassemi

All Dissertations

With advancements in semiconductor technology, power electronic devices play a critical role in modern power systems, enabling efficient energy conversion in applications such as renewable energy integration, electric vehicle drives, industrial automation, and Navy ship power systems. However, the increasing use of power converters presents challenges such as harmonic reduction, cost optimization, reliability improvement, and thermal management, especially in weight- and space-constrained environments like wind turbines and shipboard systems. High-frequency switching, while reducing passive filter size, increases thermal stress on semiconductor devices, impacting efficiency and longevity. Active thermal control, which regulates junction temperature through power loss management, and degradation forecasting, …

Live-Streaming E-Commerce: The Role Of Firms And Influencers In Driving Sales, Jingyun Hu

All Dissertations

Livestreaming is a transformative technology that removes the limitations of time and lo- cation, enabling real-time interaction between hosts and audiences. When combined with online shopping, it creates livestreaming e-commerce, a fast-growing marketing channel where influencers promote products live and engage directly with consumers.

My doctoral dissertation explores how firms and influencers collaborate effectively in this emerging retail space. Livestreaming e-commerce offers new opportunities for reaching consumers, but also raises questions about how to manage partnerships and present products in a dynamic, real-time setting. Specifically, I investigate how firms should choose and switch influencers over time, and how influencers can …

Understanding Dimensional Stability Of Polymer Surgical Mesh, Simeon J. Mckelvey

All Dissertations

Polymer surgical mesh is a biomedical implant that has revolutionized the repair of the abdominal wall and pelvic floor. Each year, over 1.6 million Americans undergo surgical procedures using polymer surgical mesh to treat conditions where internal organs protrude through weakened tissues. This material is used in approximately 90% of hernia repairs, 80% of stress urinary incontinence procedures, and 30% of pelvic organ prolapse surgeries.

Despite this widespread use of polymer surgical mesh, post-implantation complications have prompted regulatory investigation and scrutiny. These complications stem from the mesh's behavior within the human body, including wrinkling, contraction, and loss of fixation, which …

Am I Woke Enough To Serve In Healthcare: A Secondary Analysis Of Pre-Health Students’ Personal And Professional Growth By Engaging In Cultural Competency Assessments, Harolynn Williams

All Dissertations

Healthcare providers must be equipped to serve an increasingly diverse population, yet cultural competence remains underemphasized in undergraduate pre-health education. This study explored how embedded cultural competency training influences undergraduate pre-health students’ perceptions of personal and professional growth. Using a qualitative descriptive design, the research incorporated intercultural assessments, the Intercultural Development Inventory (IDI), and the Global Competence Certificate (GCC), along with qualitative reflections from students enrolled in three versions of a cultural competence course: a year-long course, a semester-long course, and a short-term study abroad immersion six-week course. Findings revealed that students demonstrated measurable growth in cultural awareness, knowledge, communication, …

An Analysis Of Principal Influence On Teacher Retention In A Rural School District: An Exploratory Qualitative Study, Stephanie Davis

All Dissertations

Research shows that nearly one-third of novice teachers leave the profession before their third year, and almost half leave by their fifth year, with turnover rates remaining steady. Teacher job satisfaction and dissatisfaction are influenced by various factors, with administrative support playing a key role. This exploratory qualitative study examined how principals' leadership behaviors affect teacher retention. Through surveys and interviews with principals and teacher representatives from nine schools, the study found that positive principal leadership significantly influences teachers' decisions to stay in their schools. Principals actively engage in behaviors, both direct and indirect, that help retain teachers. The study …

Ceramic Membrane Evaluation Via Automated Filtration Systems For Water Treatment And Resource Recovery, Weiming Qi

All Dissertations

Membranes are an advanced and mature water and wastewater treatment technology. Membrane fouling is a key difficulty for all membrane filtration processes, leading to significant attention in the literature over the years. A common problem in laboratory-scale membrane research is that the testing methods in the laboratory are often quite different than industrial applications due to the limitations of manual experimental setups. An automated membrane filtration apparatus was built in the lab to solve this problem by allowing long-term filtration, frequent backwash and CIP, and high-accuracy operation. The filtration system achieves different cleaning strategies for both theoretical research and practical …

The Effect Of Nuclear Isomers On S-Process Nucleosynthesis, Jaad Tannous

All Dissertations

s-Process nucleosynthesis is a process in which stars produce elements of mass range A = 57 to 210. Since the days of B2FH, immense work has gone into quantifying and computing s-process yields and pathways. We expand upon said work along two fronts. The first front sets up the framework for proper treatment of nuclear isomers in network calculations. We apply the framework to study 85Kr, which is a pivotal isotope in the s-process chain that affects the abundance yields of Strontium and Rubidium isotopes. In particular, we are interested in the ratio of 88Sr/86Sr and 87Rb which are important …

Synthesis Of Nanoparticles In Silicate Matrix And Stimuli Responsive Nanocomposite Polymer Films, Dimuthu Edirisinghe

All Dissertations

Interactions between aqueous metal ions and soluble silicates lead to the formation of insoluble metal silicate complexes that form nanoparticles via condensation polymerization. Metal silicates function as nanoreactors, effectively condensing metal ions into nano-sized particles that can undergo further chemical transformations. Core-shell nanostructures present an intriguing strategy for integrating materials with different properties. The silicate shell around the silver nanoparticles can be successfully infused with other metal ions, enabling subsequent reactions to tailor their properties. Silver nanoparticles exhibit strong interactions with light, surpassing other chromophores, including noble metal nanoparticles, due to their highly efficient surface plasmonic resonance. The unique optical …

Identification And Characterization Of Intermediate Phenotypes To Decipher Genetic Architecture Of Stalk Lodging Resistance In Maize (Zea Mays L.), Bharath Kunduru

All Dissertations

Maize is a key contributor to global food security and incurs severe yield losses due to stalk lodging, the permanent displacement of plants from an upright growth habit due to mechanical damage to the stem (stalk). Stalk lodging resistance, an indicator of the stalk ability to resist lodging, is a complex trait and determined by several structural, geometric, and material properties of stalks, collectively referred to as intermediate phenotypes, whose identity and genetic framework are poorly understood. Therefore, progress in resolving the genetic architecture of stalk lodging resistance was impeded by a lack of standardized phenotyping methodologies and a poor …

Decomposition And Coordination For Multiobjective Optimization: A Framework And Methodology, Philip J. De Castro

All Dissertations

In this work, we consider finding Pareto efficient solutions for complex multiobjective optimization problems (MOPs). Complex MOPs are unique in the literature because they have many more objective functions than is typically considered. In fact, such complex MOPs will have 30+ objective functions. This large problem size presents computational and coginitive difficulties. Computationally, standard techniques for solving MOPs are often ineffective and cognitively it is difficult for a decision maker (DM) to handle all of the information provided in such a large problem. To address these challenges, we develop a decomposition and coordination framework. This framework will allow us to …

Strengthening The Bonds Between Us: An Empirical Investigation Of Morale In Human-Ai Teams And The Socially Supportive Ai Teammates Who Empower It, Rohit Mallick

All Dissertations

This dissertation investigates how artificial intelligence (AI) can be designed to improve the collective emotion within a team. A team's collective emotion, or morale, describes how motivated, optimistic, and enthusiastic the group is in accomplishing its goals. We conducted four studies that compared different social support strategies that AI teammates can provide to the team. Study 1A found that AI teammates who communicate with emotions can better motivate human team members and promote awareness of team dynamics and environmental changes. Study 1B found that human teammates become more motivated and happier when their AI teammates express joy and are close …

Integrating Artificial Intelligence For Transportation Cyber-Physical Systems: From Detection To Cyber Resilience, Reek Majumder

All Dissertations

This dissertation investigates different methods for methane detection using unmanned aerial vehicles (UAVs). The author addresses the fundamental problem of methane emissions, a potent greenhouse gas responsible for global warming. The first part of the dissertation aims to create a cost-effective system for real-time methane detection and intensity prediction using ensemble learning models trained on meteorological parameters. The ensemble learning-based classification models show a high accuracy for methane detection.

The second part of the dissertation investigates cyberattack detection for UAVs using a graph-based intrusion detection system (IDS) for controller area networks (CAN). This lightweight, protocol-independent IDS uses graph-based machine learning …

Amyloid Aggregation And Mitigation, Zhenzhen Zhang

All Dissertations

The buildup of protein in tissues and organs plays a major role in unfunctional several serious diseases, including Alzheimer’s disease, Parkinson’s disease, and Type 2 diabetes, each tied to specific proteins that form harmful amyloid deposits. Amyloid aggregation typically follows a sigmoidal kinetic curve, beginning with a slow lag phase, followed by rapid fibril growth, and eventually reaching a plateau where mature, stable fibrils are formed. However, the early stage of aggregation remains particularly difficult to capture experimentally due to the highly dynamic nature and low abundance of small oligomeric species. In this dissertation, we employed discrete molecular dynamics (DMD) …

An Investigation Of Design Processes And Their Effects On Accessibility In Narrative Themed Environments, Arielle Spencer

All Dissertations

Accessibility matters, and not merely in meeting minimum codes or limited to basic necessities. Access and inclusion matter still more in places of recreation and leisure which have too often been overlooked or considered low priority, however it is precisely these places that merit special attention. Narrative Themed Environments occupy a unique position relative to the general built environment, often acting as utopic ‘other-spaces’ for enjoyment, freedom, and escape. However, for guests with disabilities, current themed experiences can often lack true inclusivity and instead create inequality, segregation, diminished experiences, and feelings of isolation and exclusion. The peculiar idiosyncratic design process …

User Acceptance Of Shared Autonomous Vehicles, Haotian Su

All Dissertations

A dissertation is proposed to explore user acceptance of shared autonomous vehicles (SAVs). SAVs are facing limited user acceptance. To systematically tackle the user acceptance barriers of SAVs, the main problem can be disintegrated into two sub-problems of user acceptance of autonomous vehicles (AVs) and ridesharing. The comfort of the ride experience in AVs is a determinant of user acceptance. Understanding the influential factors and developing methodologies to quantify human comfort in AVs are essential to facilitating future research to improve human comfort in AVs. The current pooled rideshare (PR) service closely resembles the anticipated future of SAVs. Understanding why …

A Comparison Of Carbon Ions Versus Protons For Integrated Mode Ion Imaging, Mikaël Simard, Ryan Fullarton, Lennart Volz, Christoph Schuy, Daniel G Robertson, Colin Baker, Christian Graeff, Charles-Antoine Collins Fekete

Faculty, Staff and Student Publications

Background: Incorporating image guidance into ion beam therapy is critical for minimizing beam range uncertainties and realizing the modality's potential. One promising avenue for image guidance is to capture transmission ion radiographs (iRads) before and/or during treatment. iRad image quality is typically maximized using a single-event imaging system, which involves tracking individual ions, albeit the approach is generally not suited to clinical beam settings. An alternative faster and clinically compatible method is integrated mode imaging, where individual pencil beam data is acquired, rather than single ion data. To evaluate the usefulness of transmission ion imaging for image guidance, it is …

From Epithelium To Therapy: Transitional Cells In Lung Fibrosis, Sarah Y Shin, Jichao Chen, Irit Milman Krentsis, Yair Reisner, Rodeo Abrencillo, Danielle Wu

Faculty, Staff and Student Publications

Patients with idiopathic pulmonary fibrosis and lung fibrosis secondary to infections such as influenza A and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have limited treatment options outside of supportive therapy and lung transplantation. Multiple lung stem cell populations have been implicated in the pathogenesis of lung fibrosis, and more progenitor cell populations continue to be discovered and characterized. In this review, we summarize the functions and differentiation pathways of various cells that constitute the lung epithelium. We then focus on two subpopulations of KRT5

Rna Sculpting By The Primordial Helix-Clasp-Helix-Strand-Loop (Hch-Sl) Motif Enforces Chemical Recognition Enabling Diverse Kh Domain Functions, John A Tainer, Susan E Tsutakawa

Faculty, Staff and Student Publications

In all domains of life, the ancient K homology (KH) domain superfamily is central to RNA processes including splicing, transcription, posttranscriptional gene regulation, signaling, and translation. Proteins with 1 to 15 KH domains bind single-strand (ss) RNA or DNA with base sequence specificity. Here, we examine over 40 KH domain experimental structures in complex with nucleic acid (NA) and define a novel Helix-clasp-Helix-Strand-Loop (HcH-SL) NA recognition motif binding 4 to 5 nucleotides using 10 to 18 residues. HcH-SL includes and extends the Gly-X-X-Gly (GXXG) signature sequence "clasp" that brings together two helices as an ∼90° helical corner. The first helix …

Quantifying Photon Counting Detector (Pcd) Performance Using Pcd-Ct Images, Linying Zhan, Guang-Hong Chen, Ke Li

Faculty, Staff and Student Publications

Background: Photon counting detector CTs (PCD-CTs) have recently been introduced to clinical imaging. This development creates a new need for end-users to quantify and monitor the physical performance of PCDs. Traditionally, the characterization of PCD performance relied on detector counts, which are typically accessible to the manufacturer but are not usually available to clinical end-users.

Purpose: The goal of this work was to develop a new method for quantifying PCD performance using reconstructed PCD-CT images, without requiring access to the PCD counts.

Methods: The proposed method is based on a set of closed-form relationships that connect PCD-CT image noise, the …

Dose Prediction Via Deep Learning To Enhance Treatment Planning Of Lung Radiotherapy Including Simultaneous Integrated Boost Techniques, Wenhua Cao, Mary Gronberg, Stephen Bilton, Hana Baroudi, Skylar Gay, Zhongxing Liao, Karen Hoffman, Laurence E Court

Faculty, Staff and Student Publications

Background: Recent studies have shown deep learning techniques are able to predict three-dimensional (3D) dose distributions of radiotherapy treatment plans. However, their use in dose prediction for treatments with varied prescription doses including simultaneous integrated boost (SIB), that is, using multiple prescription doses within the same plan, and benefit in improving plan quality should be validated.

Purpose: To investigate the feasibility and potential benefit of using deep learning to predict dose distribution of volumetric modulated arc therapy (VMAT) including SIB techniques and improve treatment planning for patients with lung cancer.

Methods: The dose prediction model was trained with 93 retrospective …

Natural History Models For Lung Cancer: A Scoping Review, Renu Sara Nargund, Sayaka Ishizawa, Maryam Eghbalizarch, Paul Yeh, Seyyed Mostafa Mousavi Janbeh Saray, Yimin Geng, Edwin J Ostrin, Rafael Meza, Martin C Tammemägi, Robert J Volk, Maria A Lopez-Olivo, Iakovos Toumazis

Faculty, Staff and Student Publications

Introduction: Natural history models (NHMs) of lung cancer (LC) simulate the disease's natural progression providing a baseline for assessing the impact of interventions. NHMs have been increasingly used to inform public health policies, highlighting their utility. The objective of this scoping review was to summarize existing LC NHMs, identify their limitations, and propose a framework for future NHM development.

Methods: We searched MEDLINE, Embase, Web of Science, and IEEE Xplore from their inception to October 5, 2023, for peer-reviewed, full-length articles with an LC NHM. Model characteristics, their applications, data sources used, and limitations were extracted and narratively synthesized.

Results: …