Digital Commons Network^™

A Low-Noise And High-Gain Integrated Photoplethysmography Sensor For Continuous Vital Signs Monitoring, Neethu Mohan

Dissertations

Photoplethysmography (PPG) sensing is an important technology used for measuring health parameters like, heart rate, respiratory rate, blood oxygen saturation, and blood pressure (BP). The PPG sensing is used for individuals who have to periodically monitor their health due to chronic health conditions. The basic requirements of a wearable PPG sensor include non-invasiveness, prolonged battery life, and being userfriendly. These type of sensors have great demand in the healthcare applications and there is a significant rise in the demand of these sensors. The basic objective of these PPG sensors is to make the continuous vital health monitoring easier without the …

Mathematics In Crisis: Predictors Of Achievement For Black And Latino High School Students Post-Covid-19, David Mikel Etheridge

Dissertations

This quantitative study examines systemic factors predicting math achievement for Black and Latino high school students in Chicagoland's 2025 graduating class, using public Illinois School Report Card data. It identifies teacher qualifications, chronic absenteeism, and school ratings as statistically significant predictors, confirming systemic inequities. The study advocates for structural policy reform, targeted teacher investment, and culturally responsive pedagogy to achieve equity and disrupt barriers for marginalized students.

From Classroom To Leadership: Anchoring My Leadership In Literacy, Character, And Equity, Amanda Patty-Ingram

Dissertations

My leadership journey as an urban educator has evolved through multiple roles—beginning as a classroom teacher, growing into an academic instructional coach, and now serving as an assistant principal. Across these roles, three values have consistently guided how I lead: literacy, character education, and equity. These are not separate initiatives—they are the foundation of my decisions, relationships, and instructional leadership.

Over time, I have come to understand that effective literacy leadership must be grounded in both character education and equity. Yet in practice, these values are often treated as disconnected: literacy becomes test prep, character becomes behavior compliance, and equity …

Information Technology Investment Efficiency In Federal Government Agencies: A Data Envelopment Analysis Approach, Angel Blanchard Littlejohn

Dissertations

Federal agencies invest over $115 billion annually in information technology, yet persistent questions remain about whether these substantial investments translate into improved operational efficiency and mission outcomes. Despite transparency requirements established by the Federal IT Acquisition Reform Act (FITARA) of 2014 and the creation of the federal IT Dashboard, agency leaders lack systematic frameworks for evaluating optimal IT investment levels and allocation patterns across different technology asset types.

This dissertation examines the relationship between information technology investment clusters and operational efficiency across 24 federal government agencies subject to the CFO Act. Using comprehensive data from the federal IT Dashboard spanning …

Feedback In Digital Game-Based Learning: A Taxonomy And The Design And Empirical Evaluation Of A Feedback System In A Mathematics Serious Game, André Almo

Dissertations

Digital Game-Based Learning (DGBL) is an active, student-centred pedagogical approach in which feedback plays a central role by informing learners’ actions, guiding decision-making and shaping motivation and engagement. Despite its importance, feedback in serious games is often described inconsistently and insufficiently in research, limiting comparability across studies and the accumulation of design knowledge, particularly for children. This thesis addresses these gaps through two complementary contributions: the development of a taxonomy for feedback design in digital serious games and the empirical evaluation of a taxonomy-informed feedback system in a mathematics game for primary school students. First, this work introduces the Taxonomy …

Quantum Safe Encryption (Qse) Within The Internet Of Medical Things (Iomt) Environment Using Zero Trust Architecture (Zta), Michael Grant Williams

Dissertations

This research will use a Design Science Research (DSR) methodology and show that the results would be feasible, since there will not be any actual validating or testing occurring within or on this research project because this model is a theoretical model. In addition, this proposed theoretical model is based on extensive use of NIST standards and frameworks. This theoretical model will focused on the use of Quantum-Safe Encryption (QSE) within the Vivalink Electrocardiogram (ECG) Patch Monitor Internet of Medical Things (IoMT) device in a Zero Trust Architecture (ZTA). The advancement of quantum computing (QC) is expected to …

The Heart Of An Educator An Autoethnographic Study Of Homeschool Practices That Reflect Core Udl Principles, Kimberly Clinton

Dissertations

The Universal Design for Learning (UDL) framework was at the heart of this study, which served as a critical lens for examining the instructional design practices embedded in the homeschool environment. Specifically, I examined how the three core tenets of UDL: representation, action and expression, and engagement were reflected within the Clinton Homeschool Instructional Learning Design (CHILD). The aim was to identify how homeschool instruction, as implemented by the researcher, parallels UDL principles in its responsiveness to learner variability, its emphasis on flexible instructional delivery, and its commitment to student-centered engagement. In contrast to the dominant educational paradigm, which often …

Optical Fiber Sensors Using Vernier Effect In Cascaded Fiber Interferometers, Zhouchen Wang

Dissertations

The optical Vernier effect has emerged as a powerful tool to enhance the sensitivity of optical fiber interferometer-based sensors, opening new opportunities for developing highly sensitive fiber sensing systems. Optical fiber interferometric sensors based on the Vernier effect are widely used for various applications due to their ultra-compact size, high sensitivity, immunity to electromagnetic interference, electrical isolation, resistance to harsh environments, flexibility, multiplexing capability, and remote operation. The aim of this doctoral thesis was to gain a deeper fundamental understanding of the Vernier effect in optical fiber structures and to develop and investigate a series of novel Vernier effect optical …

In Search Of Resilience: A Case Study Of Leadership In Challenging Times In An International School Setting, Bradylee W. Mcgeough

Dissertations

This study investigated the leadership of a long-serving head of an international school during six periods of significant crisis affecting the school. The study was conducted at a private school in Islamabad, Pakistan, often referred to locally as The American School.

The study paid particular attention to the development of resilience in the leader and in the follower group during and after periods of crisis. Initially designed as a heuristic inquiry, in practice the study emerged more as a collection of oral histories, although heuristic inquiry methods were employed throughout the study. Polkinghorne’s conception of narrative analysis also …

Exploring Practices Leaders Of Teleworkers Use To Foster Employee Engagement: A Phenomenological Approach, Ronald Eric Snipes

Dissertations

Purpose: The purpose of this phenomenological study was to identify and describe the leadership practices used to foster employee engagement among teleworkers in the Veterans Health Administration’s Workforce Management and Consulting division and to examine why leaders believe those practices are important to sustaining employee engagement. The study was guided by the job demands–resources (JD-R) model, which proposes that employee engagement is strengthened when job resources buffer job demands and support motivational processes. As telework continues to expand across organizations, understanding how leadership practices influence engagement in remote environments has become increasingly important.

Methodology: A qualitative phenomenological research design was …

The Culturally Intelligent Higher Education Leader: Leadership Strategies Of Exemplary California Community College Mid-Level Student Services Administrators In Creating A Culture Of Inclusiveness, Marisol Alaniz

Dissertations

Purpose: It is the purpose of this sequential explanatory mixed-method study to identify and describe the leadership strategies that exemplary mid-level student services administrators in California Community Colleges use to create an organizational culture of inclusiveness using Kennedy’s (2008) five leadership qualities.

Methodology: For this study, a sequential explanatory mixed-methods design was used. The study’s quantitative part was conducted using an online survey instrument delivered to each participant. In the survey, participants were asked whether they were willing to take part in a one-to-one follow-up interview. Once identified, qualitative research was used to conduct interviews with exemplary mid-level student services …

Replication Study Of Leadership Approaches Federal Employees Find Effective For Enhancing Morale And Productivity, Bobby Orozco

Dissertations

This study used the full range leadership model (FRLM) and lead-member exchange theory to examine leadership’s impact on federal employee morale, trust, engagement, and performance. A descriptive qualitative study design involved semistructured interviews with 16 nonsupervisory transportation security officers (TSO) at nine Northern and Southern California airports. Participants had a minimum of 2 years federal employment and 1 year union representative experience. Audio recorded interviews were transcribed verbatim and thematically analyzed using NVivo software. Organizational documents were also used to triangulate interview data. Results revealed an inspirational, caring, and collegial leadership style was most effective in enhancing morale and productivity. …

Human Resources Professional’S Job Practices In Manufacturing That Impact Employee Job Satisfaction And Retention, Alma Rosa Avalos

Dissertations

Purpose: The purpose of this explanatory sequential mixed methods study was to identify and describe employee job practices in the manufacturing industry as perceived by HR professionals that impact employee job satisfaction. The second purpose of this study was to determine which employee job satisfaction practices have the most impact on employee retention as perceived by HR professionals.

Methodology: An explanatory sequential mixed methods design examined the perceptions of 30 purposively selected Los Angeles County HR professionals. Data was collected through an online survey and interviews and analyzed using descriptive statistics, frequency tables, and qualitative analysis.

Findings: HR professionals consistently …

When Nigeria Happens To You: Finding Effective Leadership Approaches For Crisis Management And Organizational Resilience Among Nigerian Leaders, Grace Odim

Dissertations

Purpose: The purpose of this phenomenological study was to explore how Nigerian SME leaders interpret and apply leadership strategies to manage crises and build organizational resilience in volatile environments. The study focused on key dimensions of leadership, including strategic crisis navigation and vulnerability assessment, organizational resilience, contextual leadership, experiential learning and innovation, and organizational sustainability.

Methodology: This study employed a qualitative phenomenological research design to examine the lived experiences of Nigerian SME leaders who had navigated significant organizational crises. Participants were purposefully selected based on their direct experience managing disruptions that affected their businesses. Data were collected through semistructured interviews …

How Political Intelligence Sets Exemplary Mid-Level Military Women Leaders Apart, Rita Y. Ovette

Dissertations

ABSTRACT How Political Intelligence Sets Exemplary Mid-level Military Women Leaders Apart by Rita Yvette Ovete Purpose: The purpose of this exploratory phenomenological study was to identify and describe the political intelligence strategies that mid-level military women use as they respond to leadership challenges based on Reffo and Wark’s (2014) five facets of political intelligence (futurity, power, empathy with purpose, trust, and versatility). A secondary purpose of the study was to explore how mid-level military women explain their use of political intelligence strategies to support their career success and tenure while navigating leadership challenges. Methodology: This phenomenological study explored the lived …

The Art Of Crisis Leadership By Exemplary Naval Frontline Leaders, Broadus Brooks

Dissertations

Purpose: This qualitative, multiple-case study held significant importance because it aimed to identify and describe the strategies used by exemplary naval frontline leaders to lead in crisis, particularly during the COVID-19 pandemic. The study focused on the five critical tasks of strategic crisis leadership (sensemaking, decision making/coordination, meaning making, accounting, and learning), providing a unique insight into the experiences of these leaders during a crisis.Methodology: This qualitative, multiple-case study employed interviews to collect data from exemplary naval frontline leaders to identify and describe their leadership strategies during the unprecedented COVID-19 global health crisis.

Findings: Crisis leadership among U.S. naval frontline …

Meeting Battery Electric Vehicle Demand With A Focus On Throughput Capacity Across The Transport Nodes In The Upstream Cobalt Supply Chain, Nicholas J. Visconti

Dissertations

This study assesses whether cobalt transport capacity in sub-Saharan Africa is sufficient to support projected battery electric vehicle (BEV) demand under the Paris Accord. Using open-source data from ArcGIS, the Highway Capacity Manual, and the World Bank, the analysis applies a simplified linear programming approach to estimate the maximum throughput of the primary transport corridor connecting the Democratic Republic of the Congo to the Port of Durban. The model identifies significant constraints along the Rutenga-to-Beitbridge segment, reducing network capacity to an estimated 42,494 tons of ore per day. When converted to refined cobalt, this capacity falls well short of the …

A Qualitative Multiple Case Study Exploring Shifts In Thinking Of Principals Through Initiatives To Foster Relational Leadership Conducive To Retaining Teachers In High-Minority, High-Poverty Public Schools, Rita Seay

Dissertations

Problem

The public education system is broken, and teacher shortages have reached a crisis, especially in some specialty fields in United States (Carrillo & Salhotra, 2022; Podolsky et al., 2016). Lately, the teacher workforce has been described as a “leaky bucket” (Podolsky et al., 2016, p. 1). Indeed, the problems are complex in poor socioeconomic communities with racial and ethnic groups of students because teachers struggle to make a difference and, in most cases, fail due to insurmountable situations that are beyond their scope of influence (Rondfeldt et al., 2013). Evidence published that students suffer immensely from a broken, segregated …

Called To Lead: Leadership Journeys And Workplace Experiences Of Women Presidents In Seventh-Day Adventist Institutions, Gary Thurber

Dissertations

Problem

Although women constitute more than half of Seventh-day Adventist Church membership, they remain substantially underrepresented in senior leadership roles across North America. This disparity raises important questions about the historical, theological, organizational, and gender-related factors that shape women’s access to institutional leadership within the denomination. A growing body of scholarship has examined the life experiences of women clergy in the church; however, limited research has explored the experiences of women serving in presidential leadership roles within Seventh-day Adventist institutions.

Purpose

The purpose of this study was to understand and describe the experiences of women serving in presidential leadership roles …

A Ministry Manual For Supporting Pastoral Transitions: Addressing The Emotional And Spiritual Needs Of Clergy And Their Families, John Tucker

Dissertations

Pastoral transitions represent spiritually significant yet often under-supported moments in the life of clergy, congregations, and ministry networks. While leadership change is frequently framed in theological language emphasizing divine calling and institutional continuity, insufficient attention is given to the emotional, relational, and familial dimensions of these transitions. This Doctor of Ministry project examines the spiritual and emotional impact of pastoral transitions within African American church contexts, with particular attention to clergy wellbeing and systems of care.

This study employed a mixed-methods research design integrating quantitative survey data with qualitative semi-structured interviews. Survey instruments were distributed to pastors affiliated with The …

Exploring Detached Concern, A Dual-Process Emotional-Regulation Strategy, Among Intensive Care Nurses Providing End-Of-Life Care In The United States, Melissa Milton Miasek

Dissertations

Intensive care unit (ICU) nurses repeatedly provide end-of-life care (EoLC) and experience significant emotional distress, burnout, and moral distress that can lead to leaving the profession. Detached concern (DC), a dual-process emotional-regulation strategy which balances empathetic concern with emotional detachment, may support ICU nurses' emotional well-being; however, DC among nurses remains vastly understudied. This qualitative descriptive study gained deeper understanding of DC among ICU nurses providing EoLC in the United States. The study was guided by a conceptual model adapting Lampert and Glaser's dynamic DC process within Elfenbein's emotional regulation framework. The overarching research question explored ICU nurses' perspectives on …

The Desecration Of Sacred Spaces In The Dead Sea Scrolls And Pre-Nicene Latin Christianity: A History Of Interpretation Of The Eschatological Motif Of The Defiling Enemy In Apocalypticism, Rodrigo De Galiza Barbosa

Dissertations

Problem

The motif of the polluting enemy in the sanctuary is an important point of departure in the articulation of community boundaries in Hebraic-Christian culture. This particular motif has the potential to explain, at least in part, how Jewish and Christian communities would have understood the apocalyptic evil other and, from this understanding, set boundaries for their holy communities. Texts such as Dan 8 and 2 Thess 2 have been the locus classicus of the so-called antichrist, and ever since their interpretation has shaped how Christians and Jews have understood the enemy to their respective communities. In the history of …

Constructing Effectiveness: Culture, Legitimacy, And Strategic Planning In Zoos And Aquariums, Robin Keith

Dissertations

Zoos and aquariums are complex organizations operating with multiple mandates—saving species, providing exceptional care to animals, connecting communities with nature, and inspiring environmental action—making “effectiveness” difficult to define. What counts as success depends on who is asked and which goals are foregrounded. This study investigated how stakeholders in Association of Zoos and Aquariums (AZA)–accredited organizations conceptualize and operationalize effectiveness within strategic planning processes. Prior research on nonprofit and mission-driven organizations has shown effectiveness is multidimensional and often defined differently by various stakeholders. However, little has been known about how these definitions are negotiated through the practice of strategic planning, …

A Hierarchical, Data-Driven Analytical Paradigm For Strategic Planning, Operational Decision-Making, And Resilience Enhancement In United States Electric Power Systems Under Extreme Demand Conditions, Anyama Hanson Tettey

Dissertations

Historical evidence indicates that the United States electric power grid continues to face persistent criticism for reliability challenges during peak demand conditions. Extreme ambient temperatures are a primary driver of such peaks, rendering the grid most vulnerable precisely when electricity demand is highest. These demand surges are largely driven by coincident operation of heating, ventilation, and air-conditioning systems across customer classes, a trend expected to intensify as sectors such as transportation increasingly rely on electrification. Efforts to mitigate demand related unreliability have traditionally focused on system-level demand forecasting and planning, typically at the scale of cities or entire utilities. However, …

Role Of Mkp-2 In Pancreatic Beta Cell Function & Development Of Diabetes, Nabin Ghimire

Dissertations

Diabetes mellitus is a chronic metabolic disease characterized by persistent hyperglycemia. Type 1 diabetes results from autoimmune destruction of β-cells, whereas Type 2 diabetes is associated with obesity and insulin resistance. Type 2 diabetes (T2D) and metabolic-associated fatty liver disease (MAFLD) are closely linked, as individuals with T2D are twice as likely to develop MAFLD. Previous work from our lab demonstrated that overexpression of MKP-2 in obesity promotes hepatic steatosis, diet-induced obesity, reduced insulin sensitivity, and increased body weight. However, the role of MKP-2 in the onset and progression of diabetes remains unclear. The objectives of this study were to …

Exploring Drivers And Barriers To S.M.A.R.T. Goal Implementation: A Phenomenological Study Of Exemplary K-5 Public Elementary School Teachers, Rochelle Davies

Dissertations

Purpose: The research aimed to explore how exemplary K-5 public elementary school teachers in Southern California perceive the factors that support or hinder S.M.A.R.T. goal implementation, as well as their suggestions for sustaining these practices in their classrooms. This study also examined how teachers who successfully implement S.M.A.R.T. goals experience the process of using them to promote academic clarity, strengthen student ownership, and foster long-term achievement.

Methodology: The research design used qualitative phenomenological methods to collect and analyze data. Nine K-5 teachers from public elementary schools in Southern California were purposefully selected based on specific criteria. Semistructured interviews served as …

Utility Of Model-Based And Probabilistic Approaches For Rocket Engine Affordability : Exemplified On The Rs-25 Engine, Shreyas Lakshmipuram Raghu

Dissertations

Rocket engine development has historically relied on test–fail–fix (TFF) methodologies to uncover structural and fatigue deficiencies under representative operating conditions. While effective, TFF is inherently costly and schedule-intensive, often revealing life-limiting behavior late in the development lifecycle. The increasing use of additive manufacturing (AM) amplifies this challenge by introducing material property scatter and process-induced variability. Without explicit early treatment of uncertainty, these effects can increase reliance on physical testing and drive additional TFF cycles. This work presents a reliability-driven life-consistent design-bounding framework intended as an early lifecycle decision-support tool to assess and mitigate TFF risk. Although material variability is inherently …

Exploring Pregnancy-Related Empowerment And Person-Centered Prenatal Care In Black Pregnant And Postpartum Women In Alabama, Lauren Milam

Dissertations

Black women in the United States experience disproportionately high rates of maternal morbidity and mortality and often report feeling unheard, dismissed, or excluded from decision-making during pregnancy and childbirth. Understanding how Black women experience prenatal care and how those experiences relate to empowerment during pregnancy is essential for improving care and addressing persistent inequities. This study examined the relationship between person-centered prenatal care and pregnancy-related empowerment and explored Black women’s prenatal care experiences in Alabama using a sequential Quan → QUAL mixed methods design. In the quantitative phase, relationships among person-centered prenatal care, pregnancy-related empowerment, and care-related factors were examined …

Thermodynamics Of Bubble-Through Liquid-Core Nuclear Thermal Rockets, Dakota John Santana

Dissertations

Liquid-Core Nuclear Thermal Rockets (LNTR) were originally investigated in the 1960s. Exploratory efforts have thus far been relegated to preliminary models that illustrate proof-of- concept or identify theoretical limits. Collectively they would report ranges for 𝐼𝑠𝑝 between 1000 −2000 𝑠 and thrust-to-weights between 0.5 −6. This work expands a model for the Bubbler class of LNTRs into an engineering model suitable for design exploration and system model integration. Bubblers use centrifugal force to trap molten fissile fuel while bubbling propellant radially inward to cool structural members and achieve temperatures >4500 𝐾. The Bubbler model detailed herein, dubbed Fornax, expands the …

Diffusion Of Excitons In Thin Films Of Quantum Dots, Dustin Roberts

Dissertations

Quantum dots are heavily used in modern devices, such as consumer television screens, lasers, medical sensors, solar cells, and quantum computing. Their tunability and photo-stability make them candidates for a variety of applications which formerly required either dyes or significant amounts of band structure engineering. Despite all of the current and active applications, there is a gap in the current literature with regards to how energy is transported through thin films of quantum dots, and what methods may be used to control transport direction and range. The goal of this dissertation is to help fill those gaps, towards the end …