Digital Commons Network^™

Integrated Corridor Management Framework For Severe Freeway Incidents, Sanjida Afroz Iqra

Graduate Studies Theses and Dissertations 2026

Traffic incidents are a major source of non-recurrent congestion on urban freeways, generating substantial mobility, safety, and economic impacts. Severe incidents that block multiple or all travel lanes are particularly disruptive because they degrade freeway operations and propagate congestion onto surrounding arterials. Effective Integrated Corridor Management (ICM) requires the ability to identify severe incidents, estimate their network-wide impacts, and anticipate the traffic conditions and driver behaviors that contribute to instability. This dissertation develops a data-driven ICM framework to address these challenges using real-world incident, crash, detector, and connected vehicle data from major Central Florida corridors, including I-4 and SR-417. The …

Modeling And Mitigating Atmospheric Degradation In Computer Vision With Application In Renewable Energy Prediction, Sumit Laha

Graduate Studies Theses and Dissertations 2026

Weather-induced variability poses significant challenges to the reliability and performance of modern computational systems, particularly those relying on visual perception and environmental prediction. This dissertation focuses on enhancing computer vision and machine learning based predictive models that operate under varying atmospheric conditions. Two representative weather-impacted applications are investigated: image dehazing and solar photovoltaic (PV) power output forecasting. Image dehazing focuses on the restoration of clear, unobstructed visuals from hazy or foggy images, a task that is vital for various applications. On the other hand, photovoltaic (PV) power forecasting aims to predict future solar energy generation based on historical sky images …

The Perceptions Of Instructional Coaching On Teacher Efficacy And Retention In Elementary Schools, Stephanie Lucas

Graduate Studies Theses and Dissertations 2026

Administrators in a large school district in Central Florida encountered challenges regarding teacher retention and sustainability. Flite STEM coaching, a new instructional coaching model, was developed to support teachers in hopes of reducing those challenges. This model includes coaching cycles that encouraged collaboration and reflective thinking aligned with professional learning. This qualitative study focused on implementing the Flite STEM coaching model with teachers and instructional coaches. The coaching cycle consisted of the following: 1) a pre-observation conference, 2) video observation, 3) post-observation conference with feedback, and 4) a professional learning opportunity. It included DebriefScape Observation Dashboard resources to collect and …

Generating Boundary Conditions For Compound Flood Modeling In A Probabilistic Framework, Pravin Maduwantha Mahanthe Gamage

Graduate Studies Theses and Dissertations 2026

Flooding in coastal riverine environments is often driven by the combined influence of multiple hydrometeorological flood drivers, including storm surge, rainfall, waves, and river discharge, which is referred to as compound flooding. A robust flood hazard assessment requires simulation of a wide range of flood driver conditions through dynamic compound flood models to capture the variability in resultant flooding. However, such assessments remain limited by the short length of observational records and the high computational cost of physics-based methods used to generate temporally varying boundary conditions. This dissertation develops a statistical framework to characterize compound flood drivers and generate large …

Performance Analysis Of Labyrinth And Hybrid Seals For Supercritical Co₂ Turbomachinery Applications, Ghanshyam Sarobar Mandal

Graduate Studies Theses and Dissertations 2026

Leaks account for large losses in turbomachinery systems, which has led to research on sealing technologies. The work presented studies the effect of a hybrid seal combining conventional labyrinth geometry and honeycomb structure by simulating supercritical carbon dioxide (sCO₂) flow through this geometry. The CFD solver compares effects such as changes in mass flow rate, formation of vortices, pressure profile, and seal performance as geometry angles of labyrinth teeth and honeycomb walls change at conditions normally found at higher pressures in these seals. Honeycomb walls were placed on the stator, ranging from 125°< θc< 55°. Labyrinth teeth were placed on the rotor at the same degrees. Honeycomb cell diameters were also varied, creating more resistance and turbulence within the flow. It was discovered that the honeycomb angle created stronger effects on vortices and boundary layer formation, while the labyrinth angle mainly affected the throttling of flow and loss generation. Combining all three angles created a relationship dictating the seal leakage. Dimensions of seals were based on gas turbine seals with changes to meet sCO₂ conditions. ANSYS was used to simulate static and rotating conditions until convergence on a specific geometry

Experimental Demonstration Of A Laboratory Scale Packed Bed Reactor For Thermochemical Energy Storage Using Embedded Heating Elements, Zachary Monem

Graduate Studies Theses and Dissertations 2026

Thermochemical energy storage (TCES) is an emerging technology that is being studied as a carbon-neutral renewable alternative to conventional methods of large-scale power generation, such as the utilization of fossil fuels. TCES makes use of thermochemical materials to store and discharge energy in two-step reversible chemical reactions. Among the most promising TCES materials are metal oxides, which possess significantly higher energy storage densities compared to other TCES materials; consequently, thermochemical reactors are used to store and discharge large amounts of energy during reduction-oxidation cycles using metal oxide materials. The current work focuses on the design and experimental demonstration of a …

Securing The Energy Transition: Cyber-Physical Security And Resilience In Next-Generation Power Systems, Airin Rahman

Graduate Studies Theses and Dissertations 2026

Modern power systems are rapidly evolving into renewable-dominated and digitally interconnected cyber-physical infrastructures due to the increasing deployment of distributed energy resources (DERs), inverter-based technologies, and advanced control platforms. Maintaining reliability under high renewable penetration requires flexible resources capable of shifting energy across extended time horizons. Long-duration energy storage (LDES), particularly hydrogen-based energy systems, has therefore emerged as an important enabler of renewable integration, grid flexibility, and resilience. However, the growing dependence on communication, sensing, and distributed control also expands the cyber-physical attack surface of modern power systems, creating security and resilience challenges that conventional operational paradigms were not designed …

A Modular Virtual Reality Training Framework For Multi-Target Drone Defense, Susann Schleupner

Graduate Studies Theses and Dissertations 2026

Unmanned aerial systems (UAS), commonly referred to as drones, have become a rapidly growing challenge in modern military operations. In particular, the increasing use of small, agile, and low-cost systems—such as first-person-view (FPV) drones and coordinated multi-drone deployments—places high cognitive demands on operators, requiring rapid target detection, prioritization, and decision-making under time pressure.

Existing training approaches either rely on costly and logistically constrained live exercises or focus primarily on isolated piloting and shooting tasks, without sufficiently addressing these cognitive demands. At the same time, advances in commercial off-the-shelf (COTS) virtual reality (VR) hardware enable scalable, flexible, and repeatable training environments. …

Communication-Aware Energy Optimization For Electric Vehicles With Adaptive Cruise Control, Shahriar Shahram

Graduate Studies Theses and Dissertations 2026

This dissertation develops information-driven methods to reduce traction energy in battery electric vehicles during adaptive and cooperative cruise control. Physics-grounded energetics are embedded in a predictive controller that accounts for intermittent V2V preview, sensing noise, packet loss, and powertrain limits. To ensure deployability, the nonconvex traction–power map is replaced by locally convex surrogates so each step solves a small, strictly convex QP in real time (average ≈ 70 ms/step on a desktop CPU: 8 cores/16 threads, 4.2–5.0 GHz), leaving margin at typical sampling rates (Ts =0.05–0.10 s; N=15–25).

Across standardized drive cycles from NREL DriveCAT—including FTP–75 (light duty), NREL Class …

Online Risk And Harm For Marginalized Users: How Social Influence Amplifies Or Mitigates Vulnerability, Tangila Islam Tanni

Graduate Studies Theses and Dissertations 2026

Social media has reshaped how people connect, communicate, and influence one another, yet these environments also create harms that disproportionately affect marginalized users. Participation in online communities can expose users to identity-based harassment, emotional distress, and the normalization of harmful attitudes, shaping identity, well-being, and participation online and offline. Prior work has documented many forms of online harm, yet less is understood about how harmful norms and behaviors are reinforced across different forms of social media interaction, from private direct messages to online communities. Guided by the Social Ecological Model, this dissertation investigates how online harms toward marginalized users emerge …

Investigation On Selective Catalytic Reduction For Retrofit Of Commercial Aviation Aircraft Engines, Connor M. Wall

Graduate Studies Theses and Dissertations 2026

As the aviation industry continues to grow, the ever-increase of emissions from the sector becomes a growing concern. While the International Civil Aviation Organization (ICAO) set a goal of net-zero carbon emissions by 2050, there are other emissions like contrails and NOx that must still be addressed. Selective Catalytic Reduction (SCR) has been used in the transportation and power generation industry for over two decades and has been an effective solution for NOx reduction. Even with the success SCR has had in other industries, its capabilities in the aviation industry have been trivially investigated. Aircraft engines pose an unique challenge …

Volumetric Fluorescence Microscopy For High-Throughput And High-Sensitivity Imaging: From Single Molecules To Tissues, Le-Mei Wang

Graduate Studies Theses and Dissertations 2026

Fluorescence microscopy is an indispensable tool in the biological sciences, enabling researchers to investigate intricate subcellular structures, particularly for volumetric studies. However, conventional optical microscopy for volumetric imaging remains fundamentally constrained by imaging speed and throughput. To bypass traditional serial z-scanning, we introduce an axially scan-free method using a phase layer cake to modulate the system's point spread function. This approach projects volumetric information onto a 2D plane in a single shot, offering high flexibility in tuning axial depth alongside simultaneous multicolor imaging with high spatial resolution and sensitivity. This dissertation divides these technical advancements into cellular and tissue imaging …

Two Papers Exploring Cognitive Fit Theory And Data Visualization In Accounting, Kelly Wellman

Graduate Studies Theses and Dissertations 2026

This dissertation examines how data visualization design influences judgment and decision making in accounting using cognitive fit theory as a unifying framework. As visualization tools such as dashboards, Excel, Tableau, and Power BI become increasingly prevalent, understanding which design choices improve performance has become critical. The first paper provides a structured literature review of cognitive fit theory from 1991 through 2025, synthesizing research across accounting and related disciplines and tracing its evolution from early graph vs tables comparisons to mor recent work incorporating task complexity, individual differences, and design-specific features. The review identifies key gaps, including limited attention to difference …

Advanced Ysz/Si(B)Cn And Bnnt/Si(B)Cn Ceramics Matrix Composites For Extreme Environments In Hydrogen Combustion, Yiting Wang

Graduate Studies Theses and Dissertations 2026

The growing demand for carbon-neutral energy conversion has accelerated the development of hydrogen-fueled gas turbine systems, which operate at significantly higher temperatures and more chemically aggressive environments than conventional natural gas turbines. To meet these stringent requirements, ceramic matrix composite (CMC) materials consisting of yttria-stabilized zirconia (YSZ) fiber reinforced Si(B)CN ceramic matrix were developed. To further enhance in-plane heat dissipation, thermal stability, thermal shock resistance, and thermal cycling performance, a Si(B)CN/Boron Nitride Nanotubes (BNNT) nanocomposite coating was incorporated onto the YSZ/Si(B)CN composites. Microstructural characterization confirmed the formation of a continuous Si(B)CN ceramic matrix reinforced with uniformly distributed BNNTs. The resulting …

Perspectives Of Rural Educators On The Dependencies And Drawbacks Of Chat Gpt In Nigerian Higher Education Practices, Adedayo Olayinka Theodorio Dr, Francisca Jumoke Theodorio, Olumide Gbenga Olugbodi, Peter Adebowale Samson, Olusegun Olawale Olakotan

Journal of Educational Technology Development and Exchange (JETDE)

ChatGPT remains a valuable tool for transforming teaching strategies and supporting students’ comprehension of subject matter. However, its adoption and research remain uneven within the context of higher education in Nigeria. Specifically, there is limited empirical research that exemplifies real-world experiences regarding the dependencies and drawbacks in rural educational settings. This qualitative single-case study explored this phenomenon at a southwestern institution in Nigeria, involving a purposively selected group of educators. Data were gathered through participatory observation and focus group interviews, which were thematically analysed. The results indicated that the effective use of ChatGPT in rural higher education heavily depends on …

Decentralized Linear Solvers: Communication Cost And Privacy, Nelson G. Brasil, Vinay A. Vaishampayan

Publications and Research

We consider the problem of multiple parties iteratively solving a system of linear equations in a decentralized manner. Specifically, we solve for $\negr{x} \in \R^n$, the $n \times n$ system of linear equations $M\negr{x} = \negr{b}$ when each party only knows their row of the matrix $M$ and a single component of $\negr{b} \in \R^n$. Our objective is to determine the tradeoff between the accuracy of the solution and the total communication cost measured in bits. A fully connected, reliable mesh network is assumed to connect the different parties. We develop a general formulation that applies to a large class …

Voltage Stability Enhancement Of Large Load Interconnections Using Syncronous Condensers, Muhammad Ibrahim Abbas

Graduate Studies Theses and Dissertations 2026

The rapid integration of hyperscale data centers as large, concentrated loads presents a growing voltage stability challenge in grids weakened by synchronous generator retirement and increasing inverter-based resource penetration. This work proposes a Jacobian-based sensitivity framework for systematically identifying voltage-critical buses and optimally siting synchronous condensers as voltage support resources. A voltage-weighted sensitivity index, extracted from the full Jacobian inverse, is introduced to combine network-wide reactive coupling strength with observed voltage drops into a single deployable placement criterion. Validation on IEEE 14-bus and 30-bus test systems under multiple loading scenarios demonstrates that the proposed criterion consistently identifies the correct placement …

Examining Patient Safety Culture Trends In U.S. Healthcare Through A Multi-Year Analysis, Hassan Alabdullah

Graduate Studies Theses and Dissertations 2026

Patient Safety Culture (PSC) is recognized as a cornerstone of healthcare quality and a key determinant of patient outcomes. Despite the Institute of Medicine’s early calls to establish safety-oriented systems, evidence on the long-term stability of PSC in U.S. hospitals has remained limited. This dissertation addresses this gap through a multi-year evaluation of PSC using the Hospital Survey on Patient Safety Culture (HSOPSC v1.0) and advanced statistical methods. Drawing on one of the largest national datasets—comprising over 993,000 healthcare providers from 1,601 U.S. hospitals across three survey cycles (2013–2020)—the study employed a longitudinal repeated cross-sectional design. Analyses combined descriptive statistics, …

First-Principles Insights Into Electronic And Magnetic Structure At Hybrid Interfaces And Low-Dimensional Materials And Reaction On Surfaces, Bushra Ashraf

Graduate Studies Theses and Dissertations 2026

Low-dimensional materials and transition metal surfaces/interfaces provide complementary platforms for understanding how dimensionality, symmetry, spin–orbit coupling (SOC), and interfacial charge transfer/hybridization jointly control electronic structure, emergent magnetism, and surface reactivity. Using first-principles modeling with experimental comparisons, this work aims to establish interfacial structure–property relationships across low-dimensional systems.

Strained Pd adlayers on 2H-MoS₂(0001) provide a controlled platform to separate strain-driven exchange from interface-induced quenching in an itinerant d-electron metal. Although expansive strain promotes magnetism in free-standing Pd, strong Pd–MoS₂ hybridization and charge transfer suppress the monolayer moment and leave a narrow thickness window where magnetism re-emerges in …

An Algorithmic Framework For Polyhedral Gravity Modeling And Trajectory Propagation Near Small Bodies, Micah S. Boudreau

Graduate Studies Theses and Dissertations 2026

Near-Earth asteroids (NEAs) and other irregular celestial bodies have become increasingly significant targets for scientific investigation and space mission development due to their relevance to resource utilization, origins-of-life studies, planetary defense, and understanding of early solar system formation. As launch costs continue to decline, missions such as NASA’s NEAR Shoemaker, OSIRIS-REx and JAXA’s Hayabusa series demonstrate the expanding feasibility of detailed small body exploration. Despite this growing interest, most standard astrodynamics tools are not designed to model the complex, highly irregular gravitational fields that are a signature of small bodies. Such limitations pose challenges for trajectory design, navigation, and control …

Enhanced Atomization And Combustion In Subsonic Ljic Systems Using Ultrasonically Driven Solid Obstructions, Daniel Sebastian Cruz

Graduate Studies Theses and Dissertations 2026

The liquid fueling methods used in aircraft propulsion have undergone extensive optimization, with Liquid Jets in Crossflow (LJIC) emerging as a simple yet effective injection scheme. LJIC enables sufficient fuel mass flow rates and penetration for high-speed operation, however fuel trajectory and droplet size remain highly sensitive to crossflow conditions. As a result, wide flight envelopes introduce variability in atomization, leading to unsteady combustion performance. Recent work has incorporated a pintile, a solid obstruction placed in the path of the fuel jet, to redistribute momentum and reduce trajectory variability across varying flow conditions. While this approach improves trajectory uniformity, it …

Centered A Story Of Family And Compassion In The Face Of Parkinson's Disease, Savannah Hill

Graduate Studies Theses and Dissertations 2026

Centered is a three-dimensional (3D) animated short film that explores the topic of parental illness and how families must respond with compassion and adaptability when loved ones face mental or physical challenges. The story is inspired by the director’s own experience with her father’s diagnosis of Parkinson’s Disease when she was in high school. The main characters, a father and daughter, must navigate the father’s changing needs after his diagnosis by prioritizing their connection and adapting to his new physical challenges. In the film, they do this through the creation of pottery. The imperfect, handmade design style of the film …

Numerical Simulation Of Micro-Cutting Processes For The Estimation Of Material Fracture Toughness, Juan J. Lainez

Graduate Studies Theses and Dissertations 2026

Accurate determination of plane-strain fracture toughness is essential for structural integrity assessments of engineering components, yet conventional ASTM standardized testing methods require large, notched specimens that are impractical in many industrial and research contexts. This thesis presents a finite element method-based approach for estimating the mode I plane-strain fracture toughness of engineering materials from orthogonal micro-cutting simulations if the continuum damage mechanics-based fracture locus is calibrated. This method will eliminate the need for pre-cracked specimens while maintaining physically grounded fracture mechanics principles. The methodology applies to the Atkins energy-based cutting force model, in which the depth-independent intercept of the specific …

Sensitivity Analysis Of Tuned And Intentionally Mistuned Blisks To Random Mistuning, Tate A. Myers

Graduate Studies Theses and Dissertations 2026

The vibrational behavior of bladed disks, or blisks, is highly sensitive to variations in its cyclic symmetry due to variations in mass, stiffness, damping, or a combination of these factors. These inconsistencies can arise from manufacturing tolerance inconsistencies, operational wear, impacts during usage, and intentional mistuning. This thesis develops an analysis of the sensitivity of both tuned and intentionally mistuned blisks to random mistuning in their structural properties. Sobol sampling combined with state-space eigen-analysis is utilized to develop a set of randomly mistuned systems. Modal Assurance Criterion is used to track the mode shapes of each randomly mistuned system back …

Adaptability And Applications Of Advanced Laser Absorption Diagnostics In High-Pressure Shock Tube Environments, Lucas R. Pitts

Graduate Studies Theses and Dissertations 2026

Theoretical application and physical implementation of various laser absorption spectroscopy (LAS) diagnostics are examined within a high-pressure shock tube facility. Research focuses on the rationale behind the specific optical alignment layouts used across three distinct experimental campaigns, detailing the methodology required to maintain signal integrity in varied reacting flow environments. The first research campaign addresses the pyrolysis of hydroxyl terminated polybutadiene (HTPB) solid propellant binders for solid fuel ramjet (SFRJ) applications by measuring the species time histories of alkenes and aromatics. Alignment configurations prioritized beam stability and signal strength for the decoupling of overlapping absorption features to ensure measurements accurately …

Shock Tube Speciation Analysis Of Hydrocarbon Mixtures Relevant To Solid Fuel Combustion, Diego N. Ruiz Pena

Graduate Studies Theses and Dissertations 2026

Solid Fuel Ramjets (SFRJs) are often used in tactical applications due to their simplicity, robustness, and reliability. No moving parts, atmospheric oxidizer usage, and scalable fuel grain designs make them a great solution for compact, high-speed air-breathing propulsion systems. SFRJs operate by compressing incoming air through a fixed geometry inlet and directing it over a regressing solid fuel surface, where pyrolysis gases are released and transported downstream to the combustion chamber where thrust is generated. Hydroxyl-terminated polybutadiene (HTPB) is a commonly used fuel binder in SFRJ systems due to its high energy density, stable combustion behavior, and ease of processing. …

Data-Driven Seismic Site Classification Using Earthquake And Microtremor Horizontal-To-Vertical Spectral Ratios, Sanidhya Sharma

Graduate Studies Theses and Dissertations 2026

The prevailing seismic site classification parameter, the time-averaged shear-wave velocity in the upper 30 meters (V_S30), provides an incomplete representation of site conditions, neglecting deeper geology, impedance contrasts, and resonance phenomena. This thesis developed and validated a data-driven framework for seismic site classification based on the full spectral shape of Horizontal-to-Vertical Spectral Ratio (HVSR) curves combined with unsupervised machine learning, through two complementary research studies. Research 1 applied K-means clustering to earthquake-based HVSR (eHVSR) data from 3,186 ground motion stations across California and adjacent regions, identifying four physically distinct site clusters, characterized by low-frequency, very-low-frequency, high-frequency, and …

Book Review: Hwaji Shin, Being Korean, Becoming Japanese?: Nationhood, Citizenship, And Resistance In Japan, Ray Matsumoto

Asia Pacific Perspectives

No abstract provided.

Governing By Fragments: Soviet Ruins And The Architecture Of Unaccountability In Kazakhstan, Robert A. Kopack, Magdalena E. Stawkoski

Faculty Publications

This article examines two case studies in Kazakhstan with research into how Soviet institutional legacies underwrite extractive economies that render toxic costs invisible in post-Soviet setting. Through ethnographic work in Stepnogorsk (uranium processing) and the Semipalatinsk Test Site (nuclear weapons testing), we extend Gabrielle Hecht’s residual governance framework to demonstrate how inherited bureaucratic compartmentalization now serves market rather than state interests. We introduce the concept of functional nonreform to describe how distributed actors maintain Soviet-era boundaries that prevent accountability: Agencies monitor but don’t enforce, health authorities lack jurisdiction over contaminated sites, and environmental agencies measure radiation but cannot restrict land …

From Disconnection To Well-Being: A Longitudinal Study On Digital Access As A Social Determinant Of Health For Older Adults In China, Minzhi Ye, Jierong Hu

School of Social Work Faculty Publications

Objectives: This study innovatively includes digital access as a social determinant of health (SDoH) to examine the longitudinal relationship between digital inclusion and subjective well-being among older adults in China, one of the largest aging populations worldwide.

Methods: We used data from the Chinese Longitudinal Aging Social Survey (CLASS, 2016 and 2020 waves). We applied the SDoH framework to analyze the interaction between digital inclusion and social structures at the micro, meso, and macro levels. Digital accessibility was captured in waves in 2016 and 2020. Four digital accessibility trajectories were identified: continuous access, gained access, lost access, and never accessed. …