Digital Commons Network^™

Spatio-Temporal Modeling & Goodness Of Fit Testing For Ecological Fire Data, Jedidiah Olof Lindborg

Theses and Dissertations

An analysis of fire data sets resulting from controlled burns was performed. Spatio-temporal models were applied to the data sets to determine which covariates are significant in predicting fire temperature. The data sets were censored and only contain temperatures above 300C, due to a limitation in the measuring device. To handle the censoring, an extrapolation was used to reconstruct the temperatures below 300C. Models were created and run for a data set with the extrapolated temperatures and a data set with all censored temperatures removed. Several aspects of the model were evaluated, such as the chosen hyperparameters, the spatial covariance …

Multi-Dimensional Strategies Impacting Beginning Readers’ Word Solving And Engagement, Brooke Clayton

Theses and Dissertations

This dissertation studied the impact of reading instruction on beginner-level readers’ decoding skills and engagement among four first-grade students in Lexington, South Carolina. The following research question directed the study:

Will an instructional strategy foregrounded on direct, systematic phonics instruction in conjunction with multi-dimensional reading strategies improve beginner readers’ decoding skills and engagement?

The study is grounded in several theoretical frameworks, including Scarborough’s Reading Rope (Appendix A), the Simple View of Reading, the Active View of Reading (Appendix C), Onset-Rime phonics instruction, and Self-Determination Theory. Interventions included the LETRS Science of Reading Phonics Small Group Plan (Moats & Tolman, 2019) …

Filling In The Gaps: Evaluating A Self-Regulated Learning Strategy For Middle School Students Using Action Research, Leslie Eller Southerland

Theses and Dissertations

The purpose of this action research study was to evaluate the effects of a self-regulated learning innovation on middle school students’ self-regulated learning skills. One way to address problems such as student motivation, student engagement, and distracting behaviors in the classroom is to explicitly teach self-regulated learning skills such as goal setting, strategy use, self-monitoring, and systematic practice. Two research questions guided this study: (1) How and to what extent does a self-regulated learning innovation impact 7th and 8th grade students’ self-regulated learning skills (planning, self-monitoring, evaluation, reflection)? (2) In what ways do 7^th and 8^th grade students …

Functional Data Analysis On Life Expectancy And Healthcare Expenditure, Hagen Sanchez

Theses and Dissertations

This study analyzes the life expectancy for 237 countries from 1950-2023 and the healthcare expenditure for 50 countries from 1970-2022, and how life expectancy and healthcare expenditure relate to each other. Functional Principal Components Analysis was used to analyze the life expectancy and healthcare expenditure for each of the countries. Additionally, the regions of the countries were analyzed to identify any regional trends for the life expectancy data. Due to missing data and the structure of the healthcare data, multiple imputation methods and Principal Component Analysis techniques were explored for the healthcare data. Furthermore, a simulation study was conducted to …

Approaches To Enhancing Multiple Hypothesis Testing Methods With Side-Information, Siyu Zheng

Theses and Dissertations

Lesion-symptom mapping (LSM) studies offer insight into the brain areas involved in various aspects of cognition. This is commonly done via behavioral testing in patients with a naturally occurring brain injury or lesions (e.g., strokes or brain tumors). This results in high-dimensional observational data where lesion status (present/absent) is non-uniformly distributed, with some voxels having lesions in very few (or no) subjects. In this situation, mass univariate hypothesis tests have severe power heterogeneity where many tests are known a priori to have little to no power. Additionally, high-dimensional observational data can be grouped according to brain anatomical structure.

In this …

The Impact Of Teachers’ Cultural Competence On Curriculum Development In Advanced English Courses, Rhine D. Kirkland

Theses and Dissertations

As student demographics become increasingly more diverse, it is imperative that classroom teachers are responsive to the needs of learners from varied backgrounds. The purpose of this study was to examine the impact of teachers’ cultural competence on their curriculum development in advanced English courses. This case study provided insight on the use of administrative instructional coaching as a professional learning approach to aid in teachers’ creation and implementation of culturally responsive curriculums based on the tenets of Culturally Relevant Pedagogy. The analysis and triangulation of survey, interview, document, and observation data yielded key themes regarding the considerations and conditions …

A Neuro-Symbolic Ai Approach To Scene Understanding In Autonomous Systems, Ruwan Tharanga Wickramarachchige Don

Theses and Dissertations

Effectively understanding scenes requires a unified representation of scene data and background knowledge. A neuro-symbolic AI approach to scene understanding leverages such a unified representation to enable advanced expression, inference, and labeling of scenes, improving the perception of autonomous systems.

Scene understanding remains a central challenge in the machine perception of autonomous systems. It requires the integration of multiple sources of information, background knowledge, and heterogeneous sensor data to perceive, interpret, and reason about both physical and semantic aspects of dynamic environments. Current approaches to scene understanding primarily rely on computer vision and deep learning models that operate directly on …

An Efficient Detection And Deep Clustering Based Pipeline For Reliable Rodent Ultrasonic Vocalization Analysis, Sabah S. Anis

Theses and Dissertations

Ultrasonic vocalizations (USVs) are critical for understanding rodents' emotional states and social behaviors. However, manual analysis of USVs is time-consuming, subjective, and prone to errors. This thesis presents an automated pipeline that addresses these challenges by performing efficient USV detection and clustering. The proposed approach significantly reduces the time and effort needed to analyze USV data while improving accuracy and reproducibility.

To address this gap, we introduce ContourUSV, a five-step pipeline for USV detection. First, it begins with generating spectrograms from audio recordings, which are then pre-processed to enhance the contrast between USVs and background noise. Key steps include median …

Post-Selection Inference In Regression Models, Qinyan Shen

Theses and Dissertations

This dissertation develops new methodology for valid statistical inference following model selection in various regression settings. We first consider the logistic regression model for a binary response that can only be observed at the group level, as in group testing, and is subject to testing error. With the true responses only partially observed, we employ the expectation-maximization (EM) algorithm to account for missing information in the response data and simultaneously conduct variable selection using the LASSO-penalized log-likelihood function. After variable selection, we extend an existing post-selection inference method based on the polyhedral lemma \parencite{lee2016exact} to make inferences on selected covariates, …

Methods And Applications For Bayesian Semiparametric Survival Analysis, Zile Zhao

Theses and Dissertations

Survival analysis is a cornerstone of biomedical and clinical research and plays an important role in fields as diverse as engineering, actuarial science, and sociology. In this dissertation, we develop new semiparametric Bayesian methodology for three problems from survival analysis: 1) adjustment for treatment crossover in randomized controlled trials (RCTs), 2) multilevel modeling of clustered survival outcomes when the cluster size is also informative, and 3) divide-and-conquer Bayesian inference for massive survival data. Our methods are semiparametric in the sense that we assume the covariates have a linear effect with regard to the log-hazard or the log- survival time; however, …

Action Research Integrating Heggerty’S Phonemic Awareness Instruction For Transfer Into Third-Grade Writing, Jennifer Elizabeth Jones

Theses and Dissertations

Writing requires the ability to encode phonemes to separate sounds to spell. Students who are mystified by print often find writing a laborious task. This action research investigated the impact of Heggerty's Bridge the Gap phonological instruction on third grade writing development, specifically focusing on elaboration. Recognizing that strong phonological foundations are crucial for both reading and writing success, this study addressed the gap in phonological instruction found in upper elementary grades. The research questions guided the research: What is the impact of phonological awareness instruction on third-grade students’ elaboration domain in writing? 2.) What are the third-grade students' perceptions …

Characterizing Dissolved Organic Matter Composition In A Southeastern United States Watershed, Gwendolyn Marcelette Hopper

Theses and Dissertations

Dissolved organic matter (DOM) has important roles in many biogeochemical cycles. DOM is primarily composed of dissolved organic carbon (DOC), nitrogen, and phosphorus, and the processing of DOM is important for nutrient regulation and carbon cycling. In the coastal plains of the southeastern United States, there are many rivers and streams known as “blackwaters” with exceptionally high concentrations of chromophoric dissolved organic matter (CDOM) leached from terrestrial soils, coinciding with a region experiencing some of the nation’s highest rates of development. As changes in land use and climate continue to occur, DOM composition from natural to anthropogenically impacted systems can …

The Dialogic Self: Persius Satires 4 And Oikeiosis In Stoic Philosophy, William Michael Dodd

Theses and Dissertations

Though acknowledging that Persius alludes to Horace so frequently that he creates a dialogue with his elder, many commentators fail to see that Persius would challenge his predecessor. Especially evident in Satire 4, Persius' challenge to Horace stems from the younger poet's Stoicism, which philosophy he sees Horace as lampooning throughout the elder poet's Satires. Persius not only defends his Stoicism in Satires 4 but also engages with perceived weaknesses in the Epicureanism he finds in Horace. For instance, instead of the Epicurean version of natural law Persius finds in Horace, which conceives of human ties as contractual, the younger …

Determination Of Structure-Function Relationships In Hybrid Catalysts On Metal Oxide Supports, Joseph John Kuchta

Theses and Dissertations

Transition metal catalysis has revolutionized chemical synthesis, enabling efficient and selective transformations critical to the pharmaceutical, agricultural, and materials industries. However, traditional methods often rely on expensive, non-sustainable metals and harsh reaction conditions that generate significant waste. This dissertation explores a series of innovations aimed at bridging the gap between homogeneous and heterogeneous catalysis through the development of hybrid catalysts. These systems combine the molecular precision of homogeneous catalysts with the stability and practicality of heterogeneous supports, offering a pathway to more sustainable and scalable catalytic processes.

The first area of focus investigates nickel-based hybrid catalysts as a cost-effective and …

What We Don’T Know Can Hurt Them: An Examination Of Culture-Centered Pedagogy In A Diverse Elementary School, Kelly Dale Hogan

Theses and Dissertations

This qualitative action research study examined a growing cultural divide at an elementary school with a significant teacher diversity gap, best described as a discrepancy between the number of White educators compared to the number of students of color within an educational setting. Surveys were utilized to understand teachers’ cultural competency, and then all participants engaged in a book study intervention focused on culture-centered pedagogy. The study concluded with exit interviews between participants and the researcher to gauge how perceptions of working with diverse student populations progressed throughout the study. Survey responses, book study field notes, and interview transcripts were …

Investigating The Impact Of Cross-Loadings On Model Fit And Mediation Inferences In The Latent Mediator Model, Qiulin Lu

Theses and Dissertations

Cross-loadings are a common phenomenon in psychological research. Extant studies have focused primarily on measurement models, like confirmatory factor analysis (CFA), and have shown that omitted cross-loadings can bias the inter-factor correlation. These results suggest that omitted cross-loadings might likewise bias structural paths in other structural equation models (SEMs), but this area remains under-investigated. Such an effect could impact the evaluation of third variable effects, like mediation, when estimated in a SEM framework.

This study addresses this gap by examining the effects of cross-loadings in single, latent mediator model in a simulation study. The performances of conventional SEM and Bayesian …

Utilizing Culturally Responsive Teaching Practices In The Classroom, Lindsey Nicole Finley

Theses and Dissertations

This research study aimed to address the impact of teaching concepts of culturally responsive pedagogy on teachers’ understanding of their implicit biases. Additionally, it examined the impact that professional development training utilizing culturally responsive teaching (CRT) methods have on teachers working with multilingual learners (MLs). The research questions were: (1) What is the impact of teaching concepts of culturally responsive pedagogy on teachers' understanding of their implicit biases? and (2) What is the impact of intentional, ongoing professional development utilizing CRT methods for teachers working with multilingual learners? This study used a theoretical framework of culture centered pedagogies such as …

Hardware Accelerated Simulation Of Buck Converters Using Physics-Informed Neural Networks, James Clayton Crews

Theses and Dissertations

Physics-informed neural networks (PINNs) are an emerging machine learning method for learning the behavior of physical systems described by governing differential equations. Dc-dc power-electronic converters are used in a variety of industry applications such as motor drives or power supplies where real-time simulation is critical for control and safety. This thesis investigates physics-informed machine learning as an approach to develop a real-time digital twin for dc-dc power converters. Traditional numerical integration methods are used to approximate discretized behavior, and the results are compared with a trained PINN model. Modern ML frameworks (such as PyTorch and TensorFlow/Keras) are used to quickly …

The Impact Of Social Emotional Learning (Sel) Lessons On Students’ Mental Health Surrounding Standardized Testing, Margaret Denning

Theses and Dissertations

This qualitative action research examined the emotional impacts of standardized testing on 4th and 5th graders and the effects of targeted social-emotional learning lessons in a Title 1 school. Pre- and post-intervention data were gathered through surveys (Children’s Test Anxiety Scale) and focus group interviews. By employing thematic and narrative analysis, findings revealed significant initial cognitive anxiety, physical symptoms, and difficulties in self-regulation. Following the SEL intervention, the data indicated that students exhibited improved emotional resilience, reduced anxiety symptoms, and enhanced coping skills. Although the SEL interventions enhanced overall emotional well-being, anxiety was not fully eliminated. This study highlights the …

Combining Remote Sensing And Field Sampling To Assess Microphytobenthos Distribution In The North Inlet Estuary, South Carolina, Joseph Carmine Mcguinn

Theses and Dissertations

The study of microphytobenthos (MPB) distributions in mudflat ecosystems is critical for understanding coastal ecosystem health and resilience. This research integrates high-resolution multispectral imagery and elevation data to predict chlorophyll-a concentrations in mudflats within the North Inlet estuary, South Carolina. Using statistical analyses, MSAVI was identified as the most effective spectral index for chlorophyll-a prediction, and a regression model was generated for this index, finding significant correlation with elevation. Temporal and spatial patterns of chlorophyll-a distributions were explored through predictive rasters, revealing significant relationships between MPB abundance and microtopography. These findings demonstrate the value of remote sensing for …

Mo Isotopes In The Aleutian And Costa Rican Arcs: Source Variability And Juvenile Crust Formation, Ekaterina Rojas Kolomiets

Theses and Dissertations

Chemical and physical transfer between the surface, lithosphere and asthenosphere at subduction zones leads to arc magmatism and continental crust (CC) production. Subduction zones magmas and associated volcanic products sample a variety of magmatic sources that contribute to their chemical compositions in various proportions. This dissertation contributes to the study of subduction zones magmatism by assessing the relative role of subduction inputs (sediments, altered oceanic crust – AOC – and serpentinite) as flux agents in the arc magmatism and in CC formation in subduction zones under the scope of Mo isotope systematics.

I present the first Mo isotope analyses form …

Deprivation And Threat As Predictors Of Executive Functioning And Emotion Regulation In Early Adolescence: The Protective Role Of School Support, Abigail Best De Arellano

Theses and Dissertations

Childhood adversity (CA) impacts a large proportion of US youth with far reaching consequences for development and subsequent health outcomes (McLaughlin et al., 2012). Given the widespread impact of CA, it is imperative to understand how these exposures impact development, as well as identify opportunities for intervention. McLaughlin and Sheridan (2016) proposed the Dimensional Model of Adversity of Psychopathology (DMAP), providing a framework for understanding the heterogeneity of outcomes related to exposure to CA. DMAP emphasizes that deprivation (i.e., lack of expected cognitive or social stimulation) and environmental threat (i.e., exposure to harm or the threat of harm) impacts youth …

Physics Oriented Deep Learning For Material Prediction And Generation, Nihang Fu

Theses and Dissertations

The discovery of new materials is critical to advancing various industries, but traditional experimental methods for materials discovery remain slow and resource-intensive. Recent advances in machine learning (ML), particularly deep learning (DL), have greatly improved and accelerated two main aspects of modern computational material discovery: material design (e.g., material generation) and material screening (e.g., property prediction). However, a key challenge remains: standard ML models often struggle to perform domain-specific tasks effectively. Incorporating domain-specific knowledge, specifically the underlying physics of materials, into ML/DL models is key to improving the accuracy and reliability of material generation and prediction models.

This dissertation discusses …

Strategic Pricing In A Disrupted Hospitality Landscape: Asset Valuation, Competitive Behavior, And Consumer Preferences, Badr Badraoui

Theses and Dissertations

The lodging industry is experiencing profound disruption as short-term vacation rentals (STVRs) such as Airbnb increasingly compete with traditional hotels, reshaping competitive structures, consumer expectations, and pricing strategies. While prior research has examined the impact of STVRs on hotel performance metrics, significant gaps remain regarding how pricing resilience, competitive behaviors, and consumer perceptions evolve under these new conditions. In particular, little is known about how ADR-based valuation models withstand competitive pressure, how STVR hosts respond strategically to hotel pricing signals, and how consumers evaluate partitioned pricing structures across accommodation types. This dissertation addresses these gaps through three interconnected studies designed …

Investigating The Immunomodulatory Effects Of Cdk8/19 Inhibitor Senexin631 In A Her2-Positive Breast Cancer Model, Stephen O'Rourke

Theses and Dissertations

HER2-positive (HER2⁺) breast cancer is aggressive and often develops resistance to anti-HER2 therapies. CDK8 and CDK19, transcription-associated cyclin-dependent kinases (tCDKs) in the Mediator complex, are dysregulated in HER2⁺ breast cancer, correlate with poor survival, and support transcriptional escape driving therapeutic resistance. Previous studies Previous studies in immune-deficient models demonstrated that CDK8/19 inhibition (CDK8/19i) reduces pro-tumor macrophages (M2Φs), but its role in immune-competent tumors and innate immune–mediated tumor control remains unclear. Since HER2⁺ tumors are often immunogenic and anti-HER2 therapies rely on innate immune activation, reprogramming immunosuppressive M2Φ toward an M1Φ-like phenotype could enhance antitumor immunity. We hypothesized that CDK8/19i modulates …

Positive Self-Talk, Politics, And Poetry: The Impact Of A Culturally Responsive Workshop In A High School Support Lab, Danielle Ann Verwers

Theses and Dissertations

This action research dissertation describes my effort to expand access to the arts for my high school students with IEPs through a culturally responsive poetry workshop. For this qualitative study, I used ongoing content analysis to explore how the experience impacted my students and me, drawing insights from artifacts, field notes, and interview data. Predetermined categories of student identity, writing, and poetry yielded themes like positive self-talk, family, voice, and reimagining to illuminate the students’ experiences. As I analyzed my own experience, two categories of pressure and political impact emerged, characterized by freedom, growth, struggle, burnout, and hope. In addition …

Electrochemically Active Liquid Organic Hydrogen Carriers For Energy Generation And Storage, Jinyao Tang

Theses and Dissertations

The growing demand for sustainable energy has spurred interest in hydrogen as a clean energy carrier, yet its widespread adoption is limited by storage and transport challenges. Liquid organic hydrogen carriers (LOHCs) offer a promising solution by enabling reversible hydrogen storage through chemical redox reactions under ambient conditions. Compared to conventional thermal methods, LOHC electrochemistry provides improved energy efficiency, operational safety, and integration into electrochemical systems. However, key challenges remain, such as catalyst deactivation, limited redox reversibility, and low system-level performance that hinder broader application. Alcohols like isopropanol (IPA) and cyclohexanol (CHOL), and amines like ethylamine, have emerged as promising …

Beyond Entertainment: Unveiling Digital Platform Strategic Implications For International Business Growth Of Individual Entrepreneurs, Hoik Kim

Theses and Dissertations

This dissertation examines how digital identity, comprising visual, psychological, and strategic components, impacts entrepreneurial success on global digital platforms. Rather than treating identity as a static or aesthetic trait, this study conceptualizes it as a dynamic and strategic construct shaped by audience perception, algorithmic systems, and institutional environments. The research is structured into three empirical studies. The first explores how facial visibility and social media engagement affect monetization on YouTube, considering the international context. The second study empirically investigates how a biometric cue influences entrepreneurial performance on digital platforms and interprets the results through the lens of social psychological perspectives. …

Some Likelihood-Based Methods For Clustering Functional Data, Tong Shan

Theses and Dissertations

The analysis of functional data is an increasingly relevant part of statistics. The exploratory data analytic method of cluster analysis plays a very important role in different fields. Over the years, researchers have developed many clustering approaches, striving to achieve more accurate and efficient clustering. In Chapter 1, we aim to improve the accuracy of our outcome when clustering functional data. To achieve this goal, we use a predictive likelihood function which serves as an objective function to optimize in order to determine the most appropriate clusters. To optimize the objective function over the space of clustering partitions, we produce …

Saw Biosensor For The Detection Of Cyanobacteria And Cyanotoxin, Tally Bovender

Theses and Dissertations

The growing prevalence of cyanobacterial blooms and associated cyanotoxins, such as microcystin-LR (MC-LR), presents a significant threat to water quality and public health. Conventional detection methods, including ELISA and PCR, are often time-consuming, expensive, and require trained personnel, limiting their application in field settings. Hence, a miniaturized, quick testing sensor is proposed to circumvent the current sensing challenges for real time, in-situ diagnostics of MC-LR. The proposed high-frequency ultrasonic sensor employs surface acoustic waves (SAW). The sensor was designed using a multi-physics simulation tool to understand wave propagation in the piezoelectric substrate (lithium tantalate) and optimize the design of the …