Digital Commons Network^™

Shattering The Glass Ceiling, Navigating The Glass Cliffs: A Case Study Of Andrea Luxton As The First Woman President Of Andrews University (2016-2023), Maureen Sakshi Pakalahati

Dissertations

Problems

Research shows glass ceilings are thicker in faith-based institutions heavily governed by traditional beliefs and dominated by men. Research also shows singlism is on the rise in churches. There is limited research on the lived experiences of single, never married woman who reached the presidency (shattering the glass ceiling) in a faith-based institution. Leadership pundits predict a “great resignation”, which is an era of high presidential turnover, due to mounting challenges in the higher education presidency. Great resignation is a gender-neutral phenomenon, but women presidents are subject to stern criticism and penalties, leading to more disproportionate resignations. Furthermore, the …

Radar Resolution Improvements Using Reference Target Sliding Method In Range Doppler Matrix, Trent Shelton

Dissertations

A novel reference target sliding method (RTSM) in the frequency domain of post-match-filtered radar data is presented, and it is shown that target resolution can be improved to levels much finer than classical bandwidth-limited resolution metrics. The RTSM uses a priori knowledge of the radar system to test returned signals against baseline references to provide expected target fitting. The methods developed have broad application and can be used to provide crossing target resolution and estimation parameter refinement in the presence of overlapping targets. Additionally, the reduced requirement for bandwidth in target resolution will allow for low-bandwidth systems to perform on …

Pushing The Limits Of Fermi-Gbm Data, Stephen Lesage

Dissertations

The Fermi Gamma-ray Burst Monitor (GBM) is a wide-field survey instrument in a low-Earth, low-inclination orbit. It contains twelve sodium iodide detectors and two bismuth germanate detectors which together span an energy range from ~8 keV to ~40 MeV and observe the entire unocculted sky (~70%). The highest resolution GBM data product is the time-tagged event data which has ~2 microseconds temporal resolution and 128 pseudo-logarithmically spaced spectral channels. All of these factors make Fermi the perfect instrument for detecting a wide variety of high-energy terrestrial and astrophysical phenomena. In this dissertation, I implement new data analysis techniques to explore …

Frameworks For Multi-Source Image Search Using Latent Space Feature Matching, Praveen Vijayakumar Phatate

Dissertations

In this dissertation we study frameworks for image matching for three distinct application scenarios: the first relates to positioning in GPS agnostic environments, the second relates to matching and retrieving similar images in an indoor environment sourced from multiple uncalibrated cameras and the third relates to matching and retrieving satellite images across multiple uncalibrated satellite cameras. We propose three different frameworks the first one based on the idea of transformers, the second one based on the idea of autoencoders and the third one based on the idea of Siamese networks. We report extensive experiments with novel datasets for each of …

The Effect Of Micro-Sized Tin/Hard Carbon Composition On Sodium-Ion Battery Performance, Joseah Amai

Dissertations

Sodium-ion batteries represent a promising alternative to lithium-ion technology for large-scale energy storage due to sodium's abundance, global availability, and cost advantages. However, developing high-capacity anodes that simultaneously deliver substantial energy density and stable cycling performance remains a critical challenge for its commercial viability. This dissertation investigates tin/hard carbon composite anodes as a solution to the fundamental trade-off between specific capacity and cycling stability in sodium-ion battery systems. While tin offers exceptional theoretical capacity through alloying reactions, it suffers from massive volume expansion during sodiation/desodiation, leading to particle pulverization and rapid capacity degradation. On the other hand, hard carbon has …

Lost In Translation: The Impact Of Intermediate Language Representations On Machine Learning Applications, Logan Cannan

Dissertations

Machine learning assisted binary analysis is an area of great interest in cybersecurity research. Training accurate machine learning models requires methods of binary lifting, which can require binaries to be translated through an intermediate language representation. This dissertation postulates that different intermediate language representations change the performance characteristics of these machine learning models. This dissertation takes a published machine learning frameworks as a control, modifies their input methodology to include different intermediate language representation transforms, and performs direct comparisons of model performance to ascertain bias in performance caused by different intermediate languages. This research enables the machine learning engineer, focused …

An Algorithm For Three-Dimensional Bubble Simulations And Analysis For Advanced Nuclear Propulsion, Pongkrit Darakorn Na Ayuthya

Dissertations

This dissertation presents the development of a predictive simulation framework for analyzing gas-liquid dynamics in Centrifugal Nuclear Thermal Propulsion (CNTP) systems, where hydrogen gas is injected into a rotating liquid uranium fuel core. Using Smoothed Particle Hydrodynamics (SPH), a fully Lagrangian mesh-free method, this research models multiphase flow behavior under extreme conditions, capturing critical phenomena such as bubble formation, surface deformation, void fraction evolution, and rotational confinement. A novel modification to the liquid equation of state is introduced to mitigate SPH artifacts, improving fluid stability and enabling surface recovery after deformation. The model is validated against experimental data from static …

Faculty Motivation For Online Teaching And Learning, Elizabeth Sachiko Haas Greene

Dissertations

The study will examine which factors predict faculty motivation in online learning. Additionally, the study will investigate the relationship between faculty perceptions of online learning and overall online teaching and learning and the relationships that exist between perceptions of administrative support and self-efficacy for online learning. The study's findings will provide insight into how institutions can support faculty teaching in the growing online modality. The overarching method for this study is a nonexperimental quantitative study. This method will collect numerical data that can be used to measure various aspects of behavior, including attitudes (Drew et al., 2014). The study's participants …

Statistical Approaches In Evolutionary Biology: Using Threespine Stickleback Fish To Test Fisher's Geometric Model And Evaluate Methods For Handling Missing Data, Aaron Mathew Myrold

Dissertations

This thesis explores two distinct yet complementary aspects of evolutionary biology. The first chapter tests predictions from Fisher's geometric model of adaptation using a finely resolved fossil sequence of Gasterosteus doryssus spanning approximately 21,250 years. I analyze phenotypic changes in three armor traits during adaptation to a new environment and find that while step sizes follow the predicted exponential distribution—with many small steps and few large ones—they do not adhere to the model's temporal prediction that large-effect mutations should fix early in the adaptive walk. This discrepancy likely reflects adaptation from standing genetic variation rather than de novo mutation. The …

Genetic Architecture Of Complex Traits In African Ancestries Across Diverse Environments, Isadore Gregga

Dissertations

Given genetic and environmental diversity, genetic prediction based on African- ancestries individuals in the US or UK may not transfer well to other African diaspora regions. The Modeling the Epidemiological Transition Study (METS) is a longitudinal study of cardiometabolic health in five African-ancestry populations. We performed genome-wide genotyping in METS participants from the US, Jamaica, South Africa, and Ghana. We aimed to explore how genetic models for the transcriptome and body mass index (BMI) built using US- based African-ancestries populations perform in these four diverse populations. A subset of METS participants also had whole blood RNA-Seq data. For these, we …

Characterizing Niche Specialization In Staphylococcus Epidermidis, Sandra Jablonsk

Dissertations

This thesis investigates the microbial diversity of Staphylococcus epidermidis (S. epidermidis) across various anatomical sites in the human body. While traditionally viewed as a benign skin microbe, S. epidermidis also inhabits the urinary, gastrointestinal, and respiratory tracts, raising questions about its genetic variation and adaptability in different environments. The research aims to compare strains of S. epidermidis isolated from the oral cavity, nostrils, urinary tract, and skin of healthy individuals to determine if they share a common ancestor or if they evolved independently in response to specific environmental factors. The study comprises three main aims. Aim 1 focuses on assessing …

Healthcare Providers’ Lived Experiences During Pivotal Change, Lisa Raynelle Shelley

Dissertations

This phenomenological study examined healthcare providers’ lived experiences of psychological safety and administrative leader behaviors that influenced those experiences during pivotal change. While much research addressed psychological safety among frontline healthcare staff, a gap was noticed concerning providers. This study aimed to investigate the impact of psychological safety and administrative support on provider engagement, emotional response, and retention during periods of significant change. Data were collected via a survey containing multiple-choice and open-ended questions, followed by semi-structured interviews. Four findings emerged. First, the providers’ pivotal events generated themes of “workplace power dynamics,” “systemic and organizational change,” “transformational crisis,” and “physical …

Correlating Optical Phase And Atmospheric Coherence Width In Characterizing Turbulence, Scott Alexander Kaiser

Dissertations

This dissertation presents the development, validation, and optimization of a novel Hartmann Turbulence Sensor (HTS) for real-time, high-speed characterization of atmospheric optical turbulence. The HTS captures and processes live data at 1 kHz and reports turbulence parameters at 22 Hz. A key innovation is the integration of a dominant spectral component selection method into the Difference in Differential Tilt Variance (DDTV) algorithm. By using spectral analysis to identify areas of interest (AOIs) based on their dominant spatial frequency content, this method reduces computational load by up to 75% while maintaining a low RMS error. It also offers a visual representation …

Signal-To-Interference Degradation Due To Adc Dynamic Range For A Pulsed Doppler Radar Digital Signal Processor, Shawn Richard German

Dissertations

The objective of this study was to develop an expression for signal processor signal-to-interference ratio (SIR) improvement that combines factors that have historically been treated separately into a simple closed form expression, specifically factors such as analog-to-digital converter (ADC) dynamic range, phase noise, sub-quanta signal levels, signal-to-noise ratio (SNR), gain, automatic gain control (AGC), receiver noise, and signal and clutter characteristics. The SIR expression developed in this study quantifies how much a signal processor’s performance is degraded by the inclusion of an analog-to-digital converter (ADC) with respect to an equivalent well designed all-analog design. Using this unified SIR metric, expressions …

Toward Measurable Explainable Ethical Ai: An Llm-Driven Data Analytics Study, Greg Bacon

Dissertations

Large Language Models (LLMs) have been a hot area for popular and research audiences. Users marvel subjectively at Artificial Intelligence (AI) outputs — so much that OpenAI delayed public release of Generative Pre-trained Transformer 2 (GPT-2) back in 2019, citing ``safety and security concerns.'' This research advances ethical and transparent AI through qualitative and quantitative measures between user intent and LLM responses in a way that aims to assist users with clear indications of good and poor alignment and of where to backtrack to minimize bias and hallucinations. The use case is recommending grant topics in a United States Department …

Novel Ai/Ml-Based Frameworks For Protein Conformation Selection In Drug Discovery Applications, Shivangi Gupta

Dissertations

Drug development is a lengthy, expensive process with a high failure rate. The urgency brought on by the COVID-19 pandemic has accelerated the integration of artificial intelligence (AI) and machine learning (ML) to enhance drug discovery by increasing target specificity, reducing toxicity, and optimizing formulation strategies. Building on this momentum, this dissertation introduces novel AI/ML-driven frameworks for protein conformation selection and classification, addressing critical challenges in modern drug discovery. However, designing such a novel AI/ML data-driven framework is a difficult task because most real-world biomedical datasets suffer from class imbalance issues, which can significantly skew AI/ML model training, resulting in …

Manganism And The Development Of A Green Sustainable Low-Threshold Spectrophotometric Test For The Monitoring Of Manganese In Consumable Water, Anna Merritt Holmes

Dissertations

Manganism, a neurotoxic disease from the hyperaccumulation of manganese, follows an etiology that parallels Parkinsonism. Non-occupational Manganism is acquired by the lifelong accumulation of manganese through water contaminated by natural and industrial sources. Biologically active manganese (II) eludes flocculation and filtration removal methods at water utilities. The U.S. Standard Methods For the Examination of Water and Wastewater persulfate testing method uses mercury sulfate, concentrated nitric and phosphoric acids, silver nitrate, and ammonium persulfate. The low detection limit of 210 µg/L is an order of magnitude greater than the World Health Organization (WHO) allowable limit of 10-50 µg/L. In 2004, the …

Assessing The Selection And Impact Of Completeness In Technical Measure Sets In Systems Engineering, Casey Eaton

Dissertations

Technical measurement is foundational in large-scale complex engineered systems (LSCES) design and contract awards due to the state of practice of systems engineering. Although technical measurement is ubiquitous in systems engineering practice, the selection and assessment of the impact of a set of technical measures is often heuristics-based, rather than based on empirical evidence or theory. Current technical measure set selection has been observed to be subject to many challenges which, in turn, can degrade system outcomes. Two main thrusts comprise the research: selection and impact. Motivated by the potential impacts of a poor set of technical measures, a significant …

Synergizing Ground, Satellite And Numerical Weather Prediction Datasets To Derive Cloud Base Properties As Used In The Kain-Fritsch Convective Parameterization, David T. Haliczer

Dissertations

Cloud base height (CBH) and cloud base vertical velocity (CBVV) are essential parameters for understanding cloud formation, boundary layer evolution, and air exchange between the atmosphere and the boundary layer. CBH is linked to aviation safety and impacting the amount of solar radiation reaching the surface, while CBVV influences cloud development, condensation (droplet formation) and precipitation potential. High CBVV can erode capping inversions and trigger convection. These two parameters are the focus of this dissertation. CBH and maximum CBVV values were derived using a multi-linear regression equation (i.e., generalized linear models (GLM)) for CBH and a random forest model for …

Nonlinear Vortical Electron Acceleration In Magnetic Reconnection And Its Application To Solar Flares, Christopher Crawford

Dissertations

The origin of solar energetic electrons has been a long-standing problem, namely the production of a huge number of energetic electrons with power-law energy spectra within a sufficiently short time. Using particle-in-cell (PIC) magnetic reconnection (MR) simulations based on a new vortical electron acceleration model proposed by Che and Zank (CZ) [21], I first investigated the scaling of the PIC MR simulations to the observational scales of solar flares. The CZ model reproduced the sharp two-stage transition observed in soft-hard-harder electron energy spectra, implying that the electron acceleration timescale must be a small fraction of the solar flare duration. Then …

F-Region Neutral Wind Responses To Magnetospheric Forcing In The Nightside Auroral Oval, Katherine Davidson

Dissertations

High-latitude neutral winds have a number of drivers, both from solar and magnetospheric origins as well as from the lower atmosphere. The efficiency of the individual thermospheric forces, in addition to the relative strength of ion-neutral coupling, are not well characterized. Because of this, the neutral wind response to changes in ionospheric convection is not well understood, with response times ranging on the order of tens of minutes to hours. Using both data driven and modeling simulation efforts, we aim to develop a better understanding of high-latitude ionosphere-thermosphere coupling. In order to do this, three individual studies will be done …

A Rubber-Band System For Dynamic Incentivization Of Parallelized Gamified Objectives, Nicholas Diliberti

Dissertations

With the advent of videogames as the world's first mass-market interactive media, gamification has emerged as the premier way to harness powerful behavior-affecting gamified elements and place them in other contexts, such as education, fitness, and rehabilitation. This transposition, however, ignores a key tenant of user engagement: reward ought to be aligned with effort. Most, if not all, current gamification systems dispatch static reward allocations for their spread of gamified behaviors. In this paper, an alternative is presented: dynamic gamification. This dynamic gamification reads the user's current gamified state for indicators of aptitude, dynamically remaps rewards with a tuneable evaluation …

Understanding Pediatric Healthcare Access From A Black Parental Perspective : A Qualitative Study, Jessica A. Celestand

Dissertations

In the United States, healthcare access disparities have existed for several years in the African American/Black pediatric population. The District of Columbia ranks first nationally for health insurance coverage; however, African American/Black children have disproportionately experienced barriers to care compared to the District of Columbia’s pediatric population overall. There are current gaps in research that investigate African American/Black pediatric healthcare access from a parental perspective. The purpose of this descriptive phenomenology qualitative study was to explore research gaps by investigating barriers and facilitators to care, and the social determinants of health that impact pediatric healthcare access through the lens of …

Multipoint Observations Of Energetic Particle Acceleration Associated With Corotating Interaction Regions, Ashok Silwal

Dissertations

Stream Interaction Regions (SIRs) play a critical role in energetic particle acceleration and transport in the heliosphere. While shocks and compression regions associated with SIRs can accelerate particles to several MeV energies, most of our current understanding of these events is based on observations near 1 AU and beyond. Observations inside 1 AU, particularly by PSP and SolO, provide a unique opportunity to disentangle the roles of acceleration and transport. This dissertation presents the first detailed measurements of SIR-associated energetic particle events in the inner heliosphere between 0.15 and 0.80 AU using PSP, complemented by SolO and multi-spacecraft observations near …

Modeling Solar Wind In The Inner Heliosphere With Quantified Uncertainties, Dinesha Vasanta Hegde

Dissertations

The solar wind (SW) is a vital component of space weather (SWx), providing a background for solar transients such as coronal mass ejections, stream interaction regions, and energetic particles propagating toward Earth. Accurate prediction of SWx events requires a precise description and thorough understanding of physical processes occurring in the ambient SW plasma. This dissertation investigates the effect of uncertainty associated with solar photospheric boundary conditions (BCs) on magnetohydrodynamic (MHD) simulations of the SW in the inner heliosphere. For this purpose, I perform ensemble simulations of the three-dimensional SW flow using an empirically-driven MHD heliosphere model implemented in the Multi-Scale …

The Ethical Theory Of Enrique Dussel: An Investigation Of Violence And Coercion In His Three Foundational Principles, Eric Antonio Del Valle Cruz

Dissertations

Problem

Enrique Dussel's ethics proposes addressing global inequality through legitimate coercion as a means of liberating the poor, contrasting it with the violence of the current system. However, the inclusion of life-threatening acts, such as armed revolution, as coercion raises practical challenges for the Christian community, including ethical-political dialogue, inclusion of opposing parties, and potential dehumanization, which need further exploration in light of Dussel’s use of Scripture in support of his proposals.

Purpose

This dissertation aims to assess Dussel's philosophical principles and their connection to coercion and violence, ultimately establishing a framework for a conservative Christian proposal that combines the …

The Impact Of Professionalism Education And Formative Feedback In Doctor Of Physical Therapy Students Utilizing The Abbreviated Cpi Feedback Form In The On-Campus Clinic Environment, William L. Scott

Dissertations

Problem

The American Physical Therapy Association (APTA) developed the Clinical Performance Instrument (CPI) to assess the professional behaviors required for a Doctor of Physical Therapy (DPT) student to be considered "entry level" in their clinical training. Feedback from our clinical partners has indicated that, historically, students from the Andrews University DPT program have scored lower than students from other programs in several areas of the CPI during their clinical experiences. According to subjective reports from our clinical partners, these areas included safety, professional behavior, accountability, communication, and critical thinking. These five areas have been the focus of our efforts in …

Burnout And Quality Of Life As Predictors Of Compassion Fatigue In Inner-City Teachers In The United States, Helen Richelle Ceballo-Hernández

Dissertations

Problem

Teachers are under great stress which can result in burnout and the feeling of being overloaded with work. In turn, burnout can induce compassion fatigue. Compassion fatigue is often referred to in the literature as repeated exposure to others’ trauma endured by first responders, nurses, and other medical professionals as well as others in the helping profession such as therapists and social workers. The empathy of helping professionals incites compassion fatigue for those whom they help. Teachers, though not originally classified as part of the helping professions, are susceptible to compassion fatigue due to their empathy and the amount …

The Role Of Support And Prayer In Enhancing The Psychological Well-Being Of Cancer Patients In Canada, Emmanuel N. Mbah

Dissertations

Purpose of the Study

The purpose of the study was to investigate the role of family support, friends' support, community support, and prayer on the psychological well-being of cancer patients in Canada.

Methodology

A survey research method was used in this study. The survey was distributed through the QuestionPro audience and had 721 viewers, 674 respondents, and 400 participants (i.e., those who completed the survey). The survey completion rate was 59.35%, with an average completion time of 9 minutes. Most participants were Christians (62.0%), some were unaffiliated (29.5%), and the remaining participants were either Muslims, World Religion, Buddhism, Hinduism, etc. …

Inner Life, Spiritual Leadership, And Spiritual Well-Being As Predictors Of The Organizational Performance Of Employees At A Seventh-Day Adventist University In Latin America, Patricio Ordoñez

Dissertations

Problem

While traditional leadership models, such as transactional and transformational leadership, have shown success, recent research highlights the need for leadership approaches that address the spiritual and ethical dimensions of individuals in the workplace. Leaders who fail to integrate spiritual leadership risk negatively impacting employee satisfaction, creativity, and overall organizational performance. Despite the well-established concepts of inner life and spiritual well-being, more research is needed to understand their effects on employee performance in faith-based institutions. This study sought to fill that gap by examining the relationship among inner life, spiritual leadership, and spiritual well-being as predictors of organizational performance among …