Digital Commons Network^™

Design And Development Of A Direct Medium Voltage Solar Pv Resonant Inverter, Parthkumar Sureshkumar Bhuvela

Theses and Dissertations

In a grid-tied photovoltaic (PV) system connected to a medium voltage (MV) grid, an inverter is generally employed with a line frequency transformer (LFT) to connect to the grid. These LFTs are large in size and weight, exhibit high cost and losses. In recent studies, the LFTs replaced by are by (high frequency transformer) HFT embedded in DC-DC converters. These DC-DC converters are used to boost voltage levels and DC-AC inverters are employed for MV inversion. This leads to high frequency switching at MV which increases losses in inversion stage. In this study, a novel MV grid-connected solar PV inverter …

Improving Tcp Performance Using P4-Programmable Data Planes, Jose Antonio Gomez Gaona

Theses and Dissertations

The Transmission Control Protocol (TCP) forms the foundation of reliable end-to-end communication and is widely used by many applications for efficient data transfers across the Internet. TCP relies on various congestion control algorithms (CCAs) to manage its response to network congestion. These algorithms ensure fairness among competing flows and optimize the use of available bandwidth. However, since TCP is deployed within end hosts, its capacity to attain visibility of network events is constrained. This limitation arises from the closed nature of non-programmable network devices, which prevents researchers from exploring customized actions in response to network events. Recently, the emergence of …

Understanding Differential Reductions In Undernutrition Among Districts In Rwanda Through The Perspectives Of Mid-Level And Community Actors On Policy Commitment And Policy Coherence, Elyse Iruhiriye, Edward A. Frongillo Ph.D., Deanna K. Olney, Emmanuel Niyongira, Simeon Nanama, Christine E. Blake Ph.D., Rd, Eugene Rwibasira, Paul Mbonyi

Faculty Publications

Understanding the drivers of improvements in child undernutrition at only the national level can mask subnational differences. This paper aimed to understand the contributions of factors in the enabling environment to observed differences in stunting reduction between districts in Rwanda. In 2017, we conducted 58 semi-structured interviews with mid-level actors (n = 38) and frontline workers (n = 20) implementing Rwanda's multi-sectoral nutrition policy in five districts in which stunting decreased (reduced districts) and five where it increased or stagnated (non-reduced districts) based on Rwanda's 2010 and 2014/15 Demographic and Health Surveys. Mid-level actors are government officials and service providers …

Faith, Trust, And Pixie Dust: Understanding The Visions And Responsibilities Of The Varsity Esports Program Director, William Alan Fisackerly

Theses and Dissertations

The budding esports scene has drawn attention from higher education institutions in North America, who are growing community, competitive, and pedagogical esports initiatives. Varsity Esports Programs (VEPs) have proliferated since Robert Morris launched the first varsity program in 2014, with over 12,800 players from 650 institutions competing in the Spring 2023 National Association of Collegiate Esports (NACE) Starleague season alone (Butler University Set To Host NACE Starleague’s Spring 2023 Grand Finals, 2023). Despite this growth, little is known about the Varsity Esports Program (VEP), specifically from the perspective of the directors that oversee their operations. Previous work exploring the creation …

Validating An Automated Rodent Ultrasonic Vocalization Data Collator, Devin Mark Kellis

Theses and Dissertations

Rodent ultrasonic vocalizations (USVs) are a key dependent measure within behavioral science that have translational relevance with respect to medical, especially neuropsychiatric, illnesses. In recent years, several programs have been developed to enable the recording, labeling, and parameterization of rodent USVs via conventional, machine learning, or deep learning approaches. However, there remains a need to further automate the downstream process of data collation so that labeled and classified USV parameters can be rapidly formatted and analyzed via statistical approaches based on experimenter preferences. The aim of this thesis was therefore to validate an automated vocalization data collator (AVDC) to expedite …

Lexical Access In Women With The Fmr1 Premutation, Nadia Sabeh Ayon

Theses and Dissertations

Background: Emergent research indicates that women carrying the FMR1 premutation (FXpm) may encounter difficulties in language skills, including increased dysfluencies, a reduction in the quantity and diversity of words produced, and increased word retrieval errors with age (Sterling et al., 2013; Bredin-Oja et al., 2021). Objectives: The present study aims to assess semantic and phonological lexical access skills in FXpm women as well as to examine the impact of cognitive load (time pressure) on lexical access.

Methods: Forty-two FXpm women and 25 control women, aged 26-65 years (M=46.22, age-matched: p=.115), participated. The Network Production Task (Oomen & Postma, 2001), featuring …

Using Youth Participatory Action Research To Scale Up Pre-Exposure Prophylaxis (Prep) In The Southern United States, Mariajose Jhamira Paton

Theses and Dissertations

The recently launched initiative, Ending the HIV Epidemic (EHE), provides a targeted plan to end HIV in the United States (US) by 2030, and prioritizes key demographic groups and geographic areas that are disproportionately burdened by HIV. Sexual and gender minority (SGM) youth, especially Black and Latiné youth (SGMBLY), are a key population for EHE as they have experienced the largest increase in new HIV rates in recent decades. States identified by EHE are disproportionately located in the Southern US, where increasing the uptake of pre-exposure prophylaxis (PrEP) for HIV has been a challenge. Though proven effective, youth participatory action …

Scenic Design: Learning How To Think Outside The Black Box, Ashley Jensen

Theses and Dissertations

During my time in the scenic design MFA program at the University of South Carolina, the most important thing I learned is how little I knew before starting this journey. This thesis will explore the challenges I faced and the growth I experienced through the pain of it all. I will demonstrate what I learned by going through each design process step-by-step, and how I became a better artist for it.

Surface Acoustic Waves-Based Point-Of-Care Biosensor, Debdyuti Mandal

Theses and Dissertations

A biosensor is an analytical tool consisting of biologically active material used in close conjunction with a device that converts a biochemical signal into a quantifiable electrical signal. The early detection of the disease biomarkers can enhance the increased curability of the disease, reduce healthcare costs, and finally, improve the quality of life for patients. Thus, for the following purpose, there is always a need for an effective biosensor as a diagnostic device. The biosensor typically consists of an actuator, a bio-recognition component, and a transducer that converts captured signals into a meaningful display. The bio-recognition component uses biomolecules to …

Quantifying Extreme Events: Applications Of Probabilistic Methods To Quantify Riverine And Coastal Flood Dynamics In South Carolina And Neighboring Coastal Communities, Ryne Phillips

Theses and Dissertations

Extreme flood events have been persistent throughout history and have challenged human populations around the globe. Over time, scientists and engineers have developed tools and technology to support flood risk management. Most, if not all, of these tools rely on some form of the field of stochastic hydrology. Stochastic hydrology is a broad discipline, but the overarching principle is to use statistical and data-driven techniques to develop an understanding of one or more hydrologic variables (e.g., flood flow or peak storm tide). However, the need for large sample sizes of data that offer insight into all possible combinations of outcomes …

Collegiate Student-Athlete Responses To The Covid-19 Pandemic, Alexa Jenny Chandler

Theses and Dissertations

Introduction: Exercise imposes a physiological stressor on the body which is amplified as training intensifies. Collegiate fall-sport student-athletes return after summer break (off-season) and have approximately two weeks of training (preseason) with coaching staff before competition begins. The 2020 fall season was preceded by a five-month period away from campus due to the timing of the coronavirus 2019 (COVID-19) pandemic. This also meant all commercial gyms and training facilities were closed, and student-athletes were forced to train with the resources they had at home. Upon return to campus, significant changes were made to practice and competition structures in attempt to …

Control Optimization And Adaptive Tuning Of Droop Controlled Systems For Dc Bus Stability Via Terminal Impedance Shaping, Andy Wong

Theses and Dissertations

Many traditional AC systems have been moving towards DC in recent decades due to advancements in power electronics and semiconductor devices. DC power distribution systems, such as DC microgrids, have become increasing popular due to energy efficiency, resiliency, and renewable energy integration. However, with such systems which commonly utilize droop control, comes an issue of system stability due to the interconnection of multiple feedback-controlled converters to a common bus. To combat this issue, this thesis proposes a control optimization and adaptive tuning approach for maintaining DC bus stability and dynamic performance of droop controlled systems. First, a terminal impedance model …

Exploring Shape Dependency Of Catalysts For Chemical Reactions, Kaveh Shariati

Theses and Dissertations

Recent advancements in the synthesis of nanoparticles, particularly one-dimensional (1D) nanoparticles, have significantly enhanced the catalytic activity of various processes by enabling precise control over their morphologies and exposing unique crystallographic facets. The shape of nanoparticles is closely linked to their chemical, physical, electrical, optical, magnetic, and catalytic properties. This dissertation investigates the impact of 1D nanoparticle catalysts on two distinct and well-known chemical reactions. In the first part of the study, we explore the catalytic activity and selectivity of silver catalysts in the ethylene epoxidation reaction, which are intrinsically linked to their faceting. Silver nanowire catalysts representing Ag(100) and …

Examining Risk Factors For Early-Onset Breast Cancer, Jennifer Grace Taylor

Theses and Dissertations

Introduction: There have been great advancements in screening and in the identifying of risk factors associated with breast cancer, however, there is a lack of information of these factors in women with breast cancer occurring under the age of 45, known as early-onset breast cancer (EOBC). EOBC is often found at later stages, negatively impacting young women’s careers, family planning, and mental health. Additionally, because of the health disparities that exist within the U.S. health care system, women belonging to racial and ethnic groups, specifically young Black women, tend to have poorer outcomes and higher mortality rates of EOBC …

Trust In Governance System (Tgs) In The Hotel Context: Scale Development And Validation, Swechchha Subedi

Theses and Dissertations

The purpose of this study was to conceptualize trust in governance systems (TGS) within the hotel context, develop a scale to measure it, and validate its effects on hotel investment decisions. The study focused on the perspectives of hotel leadership which includes the owners, operators, and investors in the United States. The study employed a mixed-methods approach, exploratory sequential research design. Initially, the governance system within the hotel industry was conceptualized, and trust in governance was defined. The scale development phase involved generating items and dimensions through literature review, expert review, and pilot testing. The final scale included multiple dimensions …

Centralized Finance And Decentralized Finance, Leili Pour Rostami

Theses and Dissertations

This dissertation explores different facets of financial markets, focusing on the interplay between decentralized finance, traditional banking systems, and private market relationship lending. By examining these diverse areas, we aim to provide a comprehensive understanding of how emerging financial instruments and market behaviors interact with traditional financial systems. Decentralized Finance (DeFi) offers an escape from the challenges of centralized finance (CeFi). The first essay explores whether and how returns on DeFi instruments, particularly cryptocurrencies, manage to evade the traditional “rules” in response to exogenous central bank monetary policy shocks. The findings reveal that crypto abnormal returns decline significantly with shocks, …

Decisions, Decisions: Dna Damage Induced Modification Of P53 And The Effect Of Modifications On P53 Differential Binding To The Dna, Savannah Gabrielle Keating

Theses and Dissertations

p53 is the most frequently mutated tumor suppressor protein in cancer. It is highly regulated, most often via post-translational modifications (PTMs). Different pathways and target genes are differentially activated by p53 and there is much left to understand how this occurs. The regulation of p53 at the post-translational level is incredibly important to its DNA damage response, and, therefore, it is understood that PTMs are often involved in the differential activation of pathways by p53. This project aimed to identify some of the types and locations of post-translational modifications on p53 in response to different modes of DNA damage with …

Simulation Of A Passive Osmosis-Integrated Electrolyzer For Seawater Electrolysis, Masoomeh Ghasemi

Theses and Dissertations

Efforts to develop direct seawater electrolysis technology have been ongoing due to the need for pure water in electrolysis and the abundance of seawater. However, progress has been hampered by several issues, including competition with the chlorine evolution reaction, higher membrane resistance, corrosion of electrodes, and scaling from multivalent cations [1]. To avoid these issues, our project has proposed a new reactor that integrates passive osmosis (extracting fresh water from seawater) with electrolysis. In this thesis, we will discuss the operation of the osmosis-integrated electrolyzer and show theoretical predictions of the osmotic pressure differential and water flux/velocity profiles under different …

Initial Evaluation Of A Peer Supervision Program For Health Service Psychology Doctoral Students, William Bradley

Theses and Dissertations

Clinical supervision has long been utilized as the primary method of clinical training and evaluation for health service psychology doctoral students. Despite the central role that supervision has played and continues to play in the training of psychologists, little scholarly attention has been given to identifying effective methods for fostering competency in providing supervision. The lack of research in this area is concerning, given the accumulating evidence that negative supervision experiences, such as ineffective or inadequate supervision, are reported by a substantial proportion of trainees (21-92% across studies). Moreover, these experiences are associated with important proximal and distal training outcomes, …

Accessory Eyes And Dynamic Color Change In Palaemon Vulgaris, Nicholas Raymond Steichmann

Theses and Dissertations

Eyes are physiologically costly organs to produce and maintain, making the development of secondary eyes intriguing. Caridean shrimp possess reflecting superposition primary eyes, but some species across fourteen families possess an additional pair of eyes called accessory eyes along the dorso-posterior margin of the primary eyes. Secondary eyes are found in lizards, lampreys, and insects, where they often function as illumination detectors. Some shrimps may use accessory eyes to signal endocrine organs in their eyestalks to alter the pigmentation of their carapace providing better camouflage through disruptive coloration. To investigate the role of accessory eyes in dynamic color change we …

Multidimensional Simulation Of Cool Diffusion Flame, Ejaz Ahmed

Theses and Dissertations

Understanding the behavior of spherical cool diffusion flames in microgravity conditions is crucial for advancing combustion research. This knowledge has significant implications for both fundamental science and practical applications, such as spacecraft fire safety and the development of advanced, high-efficiency engines that benefit from low-temperature chemistry. Spherical cool diffusion flames are typically characterized by peak temperatures between 500 and 1000K and are often followed by the radiative extinction of a hot flame. Some low-temperature ignitions can sustain indefinitely at around 700K, leading to chain-branching pathways that produce intermediate species such as C2H4, H2O2, HO2, CH2O, CH3O, and HCO. In some …

Sleep Quality And Quantity Assessment Among African American Survivors Of Lung Cancer With And Without Chronic Obstructive Pulmonary Disease (Copd), Amanda Rae Myhren Dyer

Theses and Dissertations

Introduction: Improving the quality of life of survivors of early-stage lung cancer (NSCLC, Stages I - IIIa) requires attention to persistent, burdensome symptoms, including sleep disturbances. While research exists regarding sleep quality, sleep quantity, and sleep disturbances in cancer survivors, minimal research targets this minority survivor population. The purpose of this study was to measure and assess sleep quality, sleep quantity, and sleep disturbances among African American survivors of lung cancer. Based on the Symptom Management Theory, our comprehensive assessment focuses on a racial minority group and multiple diagnostic groups (COPD vs. No COPD). Methods: This two-group, cross-sectional, descriptive study …

Understanding Stressors, Coping Strategies, And Physical Activity Among African American Women Using Ecological Momentary Assessment, Asia Brown

Theses and Dissertations

Psychological stress is a normal part of the human experience and can be adaptive in certain contexts. However, chronic, cumulative, or uncontrollable stressors, such as those associated with living in poverty or being a member of a marginalized group, contribute to pervasive inequities among African American women including lower rates of physical activity. Given the social and political forces that continue to shape inequities, and which have exacerbated Covid-19’s impact on African Americans, it is important to gain a better understanding of how this population is experiencing and coping with current stressors, many of which are embedded within the social …

Accelerating Numerical Modeling And Optimization Of Structural Mechanical Systems, Fatemeh Hashemian

Theses and Dissertations

This research proposal presents Bayesian optimization and reduced order modeling methods to accelerate numerical analysis and design of structure mechanical system. First, a holistic framework of Bayesian optimization (BO) based on parameterized numerical models and genetic algorithm-guided adaptive sampling is developed to automate and accelerate the design of a front-loading washing machine. The research aims to address challenges associated with the model parameterization and global optimization and design. A multibody dynamics model of the washing machine incorporating a set of 9 key design variables is developed. The design variables are implemented to enable automated modifications of the dynamics model for …

Exploring The Impact Of Neonatal Transport On The Health Of Black Preterm Infants And Psychosocial Challenges Faced By Parents In Relation To Social Determinants Of Socioeconomic And Racial Inequities, Karen Faye Warren

Theses and Dissertations

Neonatal transport is a unique aspect of preterm birth. This descriptive, exploratory dissertation study used a multiple-case study design, and mixed methods approach to describe the trajectory of Black preterm outborn infants and their mothers from birth, through transport to a referral center through NICU hospitalization until discharge, for a detailed analysis of each case. The specific aims were 1) Describe each infant's transport trajectory, including baseline characteristics of the community hospital of birth (size, level of care, birthing resources), transport characteristics (mode, distance, personnel), and infant health from birth to arrival of regional referral neonatal intensive care unit; 2) …

Efficient Machine Learning On Scientific Data Using Bayesian Optimization, Rui Xin

Theses and Dissertations

Deep Learning is pivotal in advancing data analysis across various scientific fields, from genomics to materials discovery. Despite its widespread use, efficiently learning from limited data and operating under resource constraints remains a significant challenge, often limiting its full potential in environments where data is scarce or resources are restricted. This dissertation explores Active Learning and Automated Machine Learning (AutoML) powered by Bayesian Optimization to enhance the efficiency of machine learning across multiple disciplines. It focuses on algorithm optimization and data management through three interconnected studies. In the first study, we investigate how data management technique - active learning helps …

“Finally Somebody Wants To Hear Us”: Soviet Women And Political Violence In Svetlana Alexievich’S Narratives, Liubov Kartashova

Theses and Dissertations

This dissertation explores the emotional and social impact of significant Soviet historical events, including World War II, the Soviet-Afghan War, and the Chornobyl disaster, on collective memory. Svetlana Alexievich, a Belarusian Nobel Prize laureate, employs a polyphonic narrative technique to challenge official histories of these events and foreground the voices of ordinary people, particularly women. Focusing on her works – The Unwomanly Face of War, Zinky Boys, and Chernobyl Prayer – the study delves into the gendered experiences and narratives of women involved in these events. Integrating feminist scholarship on international relations and security, this research analyzes women’s roles in …

Improving Drug Repurposing Success: Integrating Large Database Claims Analysis In Drug Discovery, Joseph Magagnoli

Theses and Dissertations

Drug repurposing has emerged as an innovative strategy to identify new therapeutic uses for existing medications. However, with few notable exceptions, repurposing existing drugs has limited overall success, often failing in randomized controlled trials (RCTs) due to inadequate treatment efficacy in new clinical settings. To improve success rates, I propose a framework titled REMIDY: Retrospective and Experimental Methods Integration for Drug DiscoverY. The REMIDY framework incorporates retrospective claims analysis into the drug discovery process. I demonstrate that retrospective analysis can leverage extensive administrative and clinical data to address translational gaps between pre-clinical experimental models and RCTs. For example, pre-clinical experimental …

Therapeutic Potentials Of The Gut-Brain-Microbiota Axis For Prevention And Treatment Of Motivational Deficits In Ecohiv Infected Rats, Mason T. Rodriguez

Theses and Dissertations

People living with HIV begin to experience gastrointestinal disturbances as early as 6 months after initial infection. Regardless of adherence to combination antiretroviral therapy (cART), the gut microbiome of people living with HIV maintains a state of dysbiosis throughout the rest of their lives, providing potential for a novel target for improving the lives of those living with HIV. The present study investigated the impact EcoHIV and cocaine have on the gut microbiome of F344/N rats. Fecal samples were collected from 20 female and 20 male animals at baseline, following self-administration of cocaine, and following inoculation with EcoHIV or Saline. …

Nonverbal Iq Test Performance In Preschool-Age Children With Varying Language, Sandra Danelle Irvin

Theses and Dissertations

Purpose – This study aims to investigate the impact of two types of factors on IQ test performance in children with variation in language ability. The two types of factors studied here are: a) test characteristics (i.e., complexity of test directions) and test-taker characteristics (i.e., language ability). Method – Four participants, ages 4-7, completed norm referenced assessments for language and intelligence. Results – Descriptive results suggest no discernable trends between performance on language assessments and nonverbal IQ measures. The results demonstrated a discernable negative trend between performance on nonverbal IQ measures and linguistic complexity of instructions. Implications – While the …