Digital Commons Network^™

Tackling Toxicity And Harassment In Online Environments Through The Use Of Artificial Intelligence, Heba Saleous

Dissertations

With the increase in popularity of online communities, such as social media platforms, online games, and chatroom servers, there is a need to improve chat and content moderation. Platforms have reported an increase in the prevalence of toxic behavior and hate speech. Meanwhile, moderators are reporting difficulties in keeping up with the amount of data to check as well and the type of content they are exposed to, which further harms their own mental health. The main objective of this work is to address the challenges that exist within online communities with the rising prevalence of hate speech. Additionally, some …

Human Resource Practices And Employee Outcomes: An Examination Of Performance, Satisfaction And Diversity Climate In The Hospitality Sector Of Saudi Arabia, Tareq Abdullah Al-Jammaz

Dissertations

Tourism and related industries have become essential economic activities that play a significant role in the development, prosperity, and well-being of a country. The tourism and hotel sector in the Kingdom of Saudi Arabia (KSA) is currently undergoing significant development to diversify the national economy in line with the KSA Economic Vision 2030 Initiative. To align this sector with international standards in terms of job satisfaction and performance, human resource management practices (HRMPs) play a key role in determining the job satisfaction of employees in their various work environments. HRMPs include various job-related activities, training and development (T+D) programs, rewards, …

Pre-Service Teachers Conceptions Of Equity In Secondary Mathematics Education, Mariah Walton

Dissertations

This study investigated how pre-service mathematics teachers (PSMTs) understand equity-based pedagogies and apply equity-based pedagogical methods in their instructional planning. A central goal among educators is improving the academic achievement of racially minoritized groups, such as Black and Latinx students, who are often overlooked by traditional pedagogies. This goal has shaped the foundation of culturally relevant pedagogy and other equity-based teaching approaches. This research study focused on the intersection of equity-based pedagogical methods and secondary mathematics teaching and learning involving PSMTs in the third year of their teacher education program. Through an analysis of a discussion post assignment, a focus …

Fear, Distress, And Dissociation: Correlates Of Physiological Hyporeactivity After Interpersonal Victimization, Natalia Kecala

Dissertations

Background and Objective: Despite consistent findings of high reactivity to trauma cues in PTSD, there exists a consistent subset of physiological nonresponders who exhibit more complex and severe posttraumatic symptomatology. Research has identified different patterns of defensive reactivity representing Fear (core) and Distress (complex) PTSD symptoms. However, no studies have directly compared responders and nonresponders on physiological and clinical symptoms posttrauma.

Method: 66 adult women who had experienced first-degree sexual or physical assault within the last month were categorized using heart rate reactivity (HRR) to two personalized trauma scripts. Participants exhibiting negative HRR to both scripts were classified as nonresponders …

An Insider's Perspective To Mentoring Novice Math And Science Teachers In A University Mentoring Program: A Self-Study, Krishna R. Millsapp

Dissertations

Novice teachers benefit from individualized and cohort mentoring to help them successfully navigate student teaching and the first years of independent teaching. However, schools are experiencing a rise in attrition rates post-pandemic, especially in math and science. Mentoring, goal setting, and community-building are deemed important for retaining novices and providing them with individualized support as they navigate instructional challenges and professional responsibilities. This self-study investigates the experiences of a mentor while leading a new Professional Development & Mentoring Program for math and science novices. Educative mentoring and Hegarty’s Reflective framework helped guide the reflections of the mentor as mentoring strategies …

Examining How Adolescents From Underrepresented And Minoritzed Backgrounds View And Navigate Their Racial Ethnic Identity: Exploring The Impact Of Dominant Narratives And Counternarratives On Racial Ethnic Identity, Jesus Eduardo Ramos

Dissertations

This study delves into the impact of dominant narratives on the perceptions of Racial Ethnic Identity (REI) among adolescents from underrepresented, minoritized backgrounds and assesses the effects of counternarrative interventions. It explores how racially oppressive messages in education and media shape self-perception and examines the potential of counternarratives in challenging stereotypes, promoting critical thinking, and advancing social justice. Utilizing a qualitative cross-case study design, the research involved 8 participants aged 12-14 who identified as Hispanic/Latino or Black/African. Data collection methods included demographic questionnaires, semi-structured pre- and post-intervention interviews, and reflection logs. The analysis employed constant comparison techniques and data triangulation …

Development And Benchmark Of Polarizable Models For Ions, Luke Landry

Dissertations

Metalloproteins are ubiquitous in biology, playing crucial roles in diverse processes. Meanwhile, molecular simulations have become an important tool in scientific research. To accurately simulate metalloprotein systems, accounting for polarization and charge transfer effects is required. The fluctuating charge (FQ) model can effectively simulate the charge transfer effect, but the existing models often lack specificity for metalloproteins. In our research, a tailored FQ model for zinc-containing metalloproteins, leveraging the extended charge equilibration (EQeq) scheme, was introduced. CM5 charges were used as the target in our model parameterization, which offers advantages over RESP/CHELPG charges. Most notably, CM5 charges hold independence over …

Reclaiming Healing Spaces: A Phenomenological Study On The Transformative Power Of Outdoor Therapy From The Lived Experiences Of Black Clinicians Working With Black Clients, Lynn Murphy

Dissertations

This phenomenological study involved assessing the experiences of Black therapists who engaged Black clients in outdoor therapeutic contexts. The study was founded on the existing literature that shows the quality of the therapeutic relationship is pivotal for client retention and the Western standards that have historically favored treatment within indoor environments. To contextualize this research, a comprehensive literature review was commenced, covering topics such as the decolonization of therapy, the historical and present-day relationship between Blacks and the outdoors in the United States, sedentary lifestyles, the psychological benefits of time spent in nature, various types of outdoor therapy, and the …

Multi-Label Classification Using Conformal Prediction, Chhavi Tyagi

Dissertations

In many machine learning applications, such as image tagging, document classi-fication, and medical diagnosis, a data instance can be associated with multiple classes in parallel so that each instance is associated with multiple response variables simultaneously defining multi-label classification. Standard multi-label classification methods that provide point predictions have been developed. They lack in quantifying the uncertainty of predictions. These methods also lack in accounting for label dependencies and are very computationally expensive. This dissertation develops two methods of multi-label classification using conformal prediction that quantify the uncertainty of predictions. Chapter 1 introduces notations and tools that have been used in …

A Micromagnetic Study Of Skyrmions In Thin-Film Multilayered Ferromagnetic Materials, Nicholas J. Dubicki

Dissertations

Magnetic skyrmions are topologically protected, localized, nanoscale spin textures in non-centrosymmetric thin ferromagnetic materials and heterostructures. At present they are of great interest to physicists for potential applications in information technology due to their particle-like properties and stability. In a system of multiple thin ferromagnetic layers, the stray field interaction was typically treated with various simplifications and approximations. It is shown that extensive analysis of the micromagnetic equations leads to an exact representation of the stray field interaction energy in the form of layer interaction kernels, a so-called 'finite thickness' representation. This formulation reveals the competition between perpendicular magnetic anisotropy …

Enhancing Community Flood Resilience By Incorporating Landscape Hydrological Sensitivity And Connectivity, Wenlong Feng

Dissertations

Rapid urban expansion and dramatic climate change have significantly increased the intensity and frequency of floods worldwide. With rising flood risks, conventional flood defense strategies that rely on structural measures become ineffective. The present designations for flood-prone areas, such as FEMA's flood maps, are becoming unreliable. Flood risk management is shifting toward enhancing community flood resilience, highlighting the importance of non-structural approaches. Landscape resilience has become a foundation of community flood resilience. However, past urban development typically undermined natural hydro-ecological functions and landscape resilience because of poor recognition of landscapes' ecological role, hydrological sensitivity, and hydrological connections. This study aims …

Certifying Stability In Runge-Kutta Schemes: Algebraic Conditions And Semidefinite Programming, Austin Juhl

Dissertations

Numerical stability is a critical property for a time-integration scheme. In the context of Runge-Kutta methods applied to stiff differential equations, A-stability is one of the most basic and practically important notions of stability. Dating back to the work of Dahlquist, it has been known that A-stability is equivalent to the Runge-Kutta stability function satisfying a particular convex feasibility problem. Specifically, up to a transformation, the stability function lies in the convex cone of positive functions. In recent years, sum-of-squares optimization and semidefinite programming have become valuable tools in developing rigorous certificates of stability in dynamical systems. Therefore, it is …

Federated Learning Systems For Mobile Sensing Data, Xiaopeng Jiang

Dissertations

Federated Learning (FL) has emerged as a new distributed Deep Learning (DL) paradigm that enables privacy-aware training and inference on mobile devices with help from the cloud. This dissertation presents a comprehensive exploration of FL with mobile sensing data, covering systems, applications, and optimizations.

First, a mobile-cloud FL system, FLSys, is designed to balance model performance with resource consumption, tolerate communication failures, and achieve scalability. In FLSys, different DL models with different FL aggregation methods can be trained and accessed concurrently by different apps. In addition, FLSys provides advanced privacy-preserving mechanisms and a common API for third-party app developers to …

Data Driven Decision Making For Sustainable Planning And Operations Of Large Scale Networks, Bahareh Kargar

Dissertations

This dissertation explores data-driven decision-making networks, focusing on sustainable planning and operations for large-scale systems such as healthcare supply chains and power systems. One significant application in healthcare is the optimization of vaccine supply chains. An agent-based simulation-optimization modeling framework is developed to enhance the efficiency and sustainability of vaccine distribution. First, an agent-based epidemiological model of COVID-19 is extended to capture disease transmission dynamics and forecast the number of susceptible individuals and infections. Then, a sustainable vaccine supply chain considering the impacts of greenhouse gases is developed and integrated with the simulation model to minimize total costs and environmental …

Electrified Membrane For Water Treatment And Resource Recovery: Advancing Multiscale Strategies In Gas-Involving Reactions, Jianan Gao

Dissertations

Multifunctional, modular, and scalable water treatment technologies that operate without chemical additives are crucial for addressing global water pollution challenges. While traditional membrane-based separation processes are crucial for ensuring clean water supplies, they primarily focus on pollutant removal rather than on the upcycling of pollutants into valuable resources. Electrified membrane filtration presents a robust alternative, utilizing minimal or no chemical additives and harnessing electrical power to directly reduce contaminants or produce reactive oxidants or reductants on-site.

This dissertation is dedicated to the development of innovative electrochemically reactive membranes designed to address three major challenges: (1) the engineering of electrocatalysts with …

A Methodological Framework For Ontology Development, Enrichment, And Application In Natural Language Processing Tasks, Navya Martin Kollapally

Dissertations

Electronic Health Records (EHRs) have been widely used in healthcare to record demographics, vital signs, test results, immunizations, medical imaging reports, differential diagnoses, etc. It is now accepted that non-clinical (e.g., social) factors have a substantial influence on health outcomes. Hence, it is desirable to record these Social and Commercial Determinants of Health (SDoH & CDoH) in an EHR. The "non-text parts" of EHR notes (e.g., data tables) rely on coded terms from underlying ontologies or terminologies to facilitate semantic interoperability. Ontologies help define concepts, the relationships between them, and instances that can be utilized in research.

The first accomplishment …

Microwave Catalysis-Enabled Membrane Processes For Microbial Inactivation, Fangzhou Liu

Dissertations

The COVID-19 pandemic has highlighted the urgent need for advanced technologies to combat virus transmission. Traditional membrane filtration technologies primarily serve as physical barriers, capturing pollutants but failing to inactivate microbial agents such as bacteria and viruses. These membranes typically target larger particles but are ineffective against sub-micrometer viral particles. Thus, there's a critical demand for membrane filtration processes that combine robust filtration with antifouling and reaction -enabled functions for efficient pathogen disinfection. This research explores a novel microwave-assisted membrane filtration process incorporating catalytic reactions to enhance microbial disinfection and prevent membrane fouling, offering a groundbreaking solution to global challenges …

Estimation Of Spo2 Levels And Heart Rate From Ppg Signals In The Presence Of Motion Artifacts, Chizhong Wang

Dissertations

In the rapidly advancing world of health technology, wearable devices are at the forefront, fundamentally changing how individuals monitor their health. The key to this transformation is photoplethysmography (PPG), a non-invasive optical method that measures blood flow variations through the skin by detecting changes in light absorption with each heartbeat. This capability makes PPG essential for monitoring vital signs such as heart rate and blood oxygen saturation(SpO₂). Furthermore, the utility of PPG signals has been extended beyond traditional health metrics to include human activity classification, offering a holistic perspective on an individual's physical health and activity levels, in …

Order-Picking Strategies And Efficiency Models For The Fulfillment Of Multi-Line E-Commerce Grocery Orders, Zijia Wang

Dissertations

The fulfillment process for Buy Online Pickup from Store grocery orders (BOPS-Grocery) is particularly challenging, given the large item count per order and the low-profit margins. This research investigates the BOPS-Grocery model and pursues the following objectives: (i) Defining and specifying the BOPS-Grocery fulfillment process. Differentiating the process from classical warehouse order picking., identifying performance objectives, and characterizing design options and facility layout. (ii) Modelling and developing order picking algorithms specific to the straight aisle section. Formulated as an order hatching problem with picker movement minimization. No order splitting, and (iii) modeling and developing order picking algorithms specific to the …

Numerical Techniques For Improving Simulations Of Tropical Cyclones, Yassine Tissaoui

Dissertations

The increasing frequency and intensity of tropical cyclones (TCs) due to climate change pose significant challenges for forecasting and mitigating their impacts. Despite advancements, accurately predicting TC rapid intensification (RI) remains a challenge. Large eddy simulation (LES) allows for explicitly resolving the large eddies involved in TC turbulence, thus providing an avenue for studying the mechanisms behind their intensification and RI. LES of a full tropical cyclone is very computationally expensive and its accuracy will depend on both explicit and implicit dissipation within an atmospheric model. This dissertation presents two novel numerical methodologies with the potential to improve the efficiency …

Large Deviation Theory In Stochastic Processes: Applications To Biological Modeling, Moshe C. Silverstein

Dissertations

This dissertation delves into developing and applying stochastic models to analyze complex biological systems. It leverages Large Deviation Theory (LDT) to gain insights into these systems, focusing on two key examples: neural networks and calcium signaling dynamics. Traditional deterministic methods frequently fail to capture biological processes' randomness and inherent variability. Meanwhile, many stochastic approaches struggle to be mathematically tractable or provide accessible insights. The approach introduced in this study provides rigorous mathematical frameworks to enhance understanding of these stochastic behaviors while remaining tractable and insightful.

A stochastic model for a random biological neural network is constructed that addresses the dependencies …

Efficient Numerical Methods For Monge-Ampere Type Equations, Jake S. Brusca

Dissertations

Current numerical methods for Monge-Ampere-type equations and Optimal Transport problems face challenges when handling higher dimensions and large-scale data. This dissertation aims to develop and analyze efficient, highly parallelizable numerical algorithms for solving the Monge-Ampere equation to address these issues. Two approaches are employed:

(1) The discretization method is enhanced by introducing an integral repre-sentation of the Monge-Ampere operator. This integral can be discretized using higher-order quadrature, yielding a more efficient, higher-order monotone scheme that allows for narrower stencils. An additional advantage of this discretization is its natural extension to arbitrary dimensions.

(2) The nonlinear solvers for this scheme are …

History Education: Learning History From Community College Students’ Perspectives, Mylinh V. Pham

Dissertations

Given the current political climate of division, the study of history is important now more than ever, but the value of the study of history has been marginalized. This study used student focus groups to understand ways in which history could be taught in such a way that its importance is emphasized through relevance and connection to current social and political issues and through student-centered learning. This study also determined how history could help students evaluate and think critically about historical content. This study drew on the experiences of community college students who have taken a higher education history course …

Con Respeto Y Dignidad: Transforming Educational Experiences For Students Of Color By Addressing Disproportionate Discipline Practices, Selene Munoz

Dissertations

Discipline practices wield significant influence over the social dynamics within educational settings and profoundly impact students’ ability to attain academic and social gains crucial for their success. The racialization of school discipline has been linked to negative effects on student’s academic trajectories and life outcomes. Consequently, school administrators can play a crucial role in effecting cultural change within their organizations to support disciplinary practices that uphold students’ educational dignity. This study looked at the strategies employed by secondary level administrators to shift their school cultures aimed at addressing disproportionate disciplinary practices. Using a mixed methods approach, this study draws upon …

Factors Influencing Teacher Retention In K-12 Public Schools In Rural Hawai’I As Perceived By K-12 Public School Teachers, Celeste Akiu

Dissertations

Purpose. This qualitative study aimed to identify and describe the factors influencing teacher retention in K-12 public schools in rural Hawai’i, as perceived by K-12 public school teachers examined within the framework of Mason and Matas’ (2015) conceptualization of four capital factors: human, social, structural, and positive psychological. Methodology. This qualitative study intended to identify factors that influenced teachers in rural Hawai’ian communities to remain in the profession. Convenience purposeful sampling was used to identify the nine teachers who participated in this study. The Four Capital Framework for Teacher Retention was used to guide the questions used in the interviews, …

Localized Hermite Method Of Approximate Particular Solutions, Kwesi Acheampong

Dissertations

A localized Hermite method of approximate particular solutions (LHMAPS) is presented in this dissertation. This method is designed to improve the accuracy of the localized method of approximate particular solutions (LMAPS) for solving partial differential equations. LMAPS is a strong-form method that defines local radial basis function approximations to the solution values at a group of collocation points before applying the differential operator to this approximation function. Based on the LMAPS's local scheme, LHMAPS seeks Hermite-type local approximations based on both function values and derivatives. Numerical experiments validate the superior accuracy of the proposed method to the LMAPS by solving …

Elevating Commodity Polymers To Advanced Applications In Polymer Photonics And Polymer-Derived Porous Materials, Mark Robertson

Dissertations

Since the inception of synthetic polymers, polymer-derived materials have permeated into essentially all aspects of our daily lives. The most commonly thought of examples of polymer materials involve single-use, disposable products to increase shelf lives of perishable items, act as personal protective equipment, or provide some degree of convenience for the consumer. However, as we have furthered our understanding of polymer chemistry and polymer physics to develop increasingly sophisticated polymer systems, polymer materials have been employed in incredibly advanced applications. These include solid electrolytes for energy storage, matrices for aerospace grade carbon fiber-reinforced composites, membranes for liquid and gas separations, …

Development And Evaluation Of An Instrument For Exploring Achievement Emotions Of General Chemistry Students: General Chemistry Achievement Emotions Questionnaire, Alexander Graves

Dissertations

General Chemistry, a course that is required for many STEM degree programs, is often perceived as a difficult and stress-inducing course by students. One aspect of a student’s course experiences that can be measured are achievement emotions. Emotions that students can experience that can affect and are affected by academic performance are called achievement emotions. Achievement emotions, such as anxiety, have been extensively studied in recent years in relation to student performance and retention in different courses. Instruments that have been developed to measure achievement emotions in broad academic settings. However, achievement emotions have been determined to be domain-specific, meaning …

Effects Of School-Based Physical Activity On Children’S Core Executive Function Abilities, Jessie Katelyn Johnston

Dissertations

Children in the United States are becoming increasingly sedentary, linked to detrimental effects on both physical and mental health. Introducing physical activity interventions in schools offers a promising approach to address this trend, while also enhancing children’s executive functioning abilities. Executive functioning abilities are crucial for social-emotional development and academic success. Therefore, the purpose of this study was to explore whether a 6-week physical activity intervention at moderate intensity was associated with increases in executive functioning among girls who are enrolled in third through fifth grade. It was hypothesized that executive functioning abilities (working memory, inhibition, and cognitive flexibility) would …

Labor Market Alignment And Social Outcomes, Holly Katherine Schmitt

Dissertations

The purpose of this interpretive case study was to investigate how several community colleges work with local industry partners to create market alignment and uncover the social outcomes within their communities. Most studies within labor market alignment focus on the economic outcomes, but this study sought to review the social outcomes. This study explored practitioners’ commitment and their pursuit to further students' career opportunities through increased stakeholder engagement and credential alignment by investigating how industry initiatives impact diverse groups of students, creating new opportunities for career and social impacts. Some outcomes include status markers of economic freedom, while others seek …