Digital Commons Network^™

Inter-Basin Groundwater Flow In West-Central Florida, Sally Yousef Elrashedy Dr

Graduate Thesis and Dissertation post-2024

The mean annual values of inter-basin groundwater flow (IGF) and its inter-annual and seasonal variability across 172 watersheds in west-central Florida were estimated using the Integrated Northern Tampa Bay (INTB) model, which is an application of the Integrated Hydrologic Model dynamically coupling HSPF and MODFLOW. The estimated IGF for the scenario without human fluxes shows spatial heterogeneity in the model domain ranging from -1291mm/year to 4808 mm/year, and the variability of IGF decreases with spatial scales. A region with gaining IGF is defined as groundwater importer and a region with losing IGF is defined as a groundwater exporter. The characteristics …

The Effects Of Camera, Environmental, And Motion Properties On Simultaneous Localization And Mapping, Esteban Segarra Martinez

Graduate Thesis and Dissertation post-2024

Simultaneous localization and mapping (SLAM) is the process of estimating the pose of a robot within an unknown environment. A variant, visual SLAM (V-SLAM), estimates the pose only using visual information from a camera. In recent years, the importance of V-SLAM has increased and expanded to applications such as robotics, virtual reality, augmented reality, and autonomous driving. Accurate estimation of poses is critical as these applications need to quickly perceive an environment and update its pose under complex scenarios. V-SLAM is composed of algorithms that utilize robot vision to distinguish landmarks in the environment in order to estimate the geometric …

Integration Of System Dynamics And Agent-Based Simulation To Emulate Cyberattacks In An Iot-Based Smart Grid, Francisco Valdez

Graduate Thesis and Dissertation post-2024

The electric power grid is a cyber-physical system (CPS) that plays a fundamental role in modern society. With the integration of renewable energy sources and advanced communication technologies, Smart Grids (SGs) can enhance both the profitability and reliability of the electric power system. The communication network that interconnects numerous remotely distributed generators, devices, and controllers plays a vital role in grid control, and current trends favor the widespread adoption of Internet of Things (IoT) devices. However, this network is inherently vulnerable to cyberattacks. This dissertation presents a hybrid methodology to model and analyze the dynamic behavior of an electrical Smart …

Critical State-Based Study On Deformations Due To Construction Activities And Blast Densification, Jorge Enrique Orozco-Herrera

Graduate Thesis and Dissertation post-2024

The behavior of geo-structures and foundation systems in densely populated urban areas relies on the successful performance of the supporting soils when subjected to static (e.g., the weight of the structure or service loads) or dynamic (e.g., earthquake-induced ground motions, construction-induced vibrations, wind loads, or traffic) loading scenarios. Construction-related activities and ground improvement operations can also be responsible to alter the stress-strain-strength behavior of supporting soils by causing vibration-induced ground deformations, excessive vibrations, or mobilizing soil shear strength in relation to in situ or as-built conditions. Construction-related activities and ground improvement operations such as blast densification trigger complex dynamic input …

Additively Manufactured Engineered Transparent Ceramics For Laser Gain Media, Ross Osborne

Graduate Thesis and Dissertation post-2024

Transparent ceramics (TCs) offer a key advantage over single crystals as solid-state laser materials, in that their composition can be spatially varied to improve laser performance. In this work, additive manufacturing (AM) techniques were applied to TC fabrication to produce laser gain media with engineered gain and index profiles. We have used direct ink write (DIW) to fabricate laser rods and channel waveguides and introduced ink-spraying, a new technique, to realize multilayer planar waveguides. Modifications to the DIW process, including the use of sacrificial drying layers to promote uniform drying, the optimization of the drying, burnout and calcination steps all …

Fundamental Mechanisms For Flame Acceleration And Detonation Phenomena, Rachel Hytovick

Graduate Thesis and Dissertation post-2024

Hypersonic propulsion via scramjets and detonation engines is enabled through the acute understanding of deflagrations, detonations, and multiphase interactions. Deflagrations are explored to understand the compressible flame regime for scramjet unstart and detonation transition in reacting systems. Compressible flames are experimentally classified with a comprehensive diagnostic suite combining particle image velocimetry (PIV), chemiluminescence, schlieren, and pressure measurements in a turbulent shock tube. Several gaseous fuels are explored to identify the universal mechanism responsible for flame compressibility and acceleration. The ability to compress deflagrations and accelerate the system to a detonation directly relies in the successful conversion of energy available to …

A Comparative Analysis Of Figurines From The Lower Rio Verde Valley From Oaxaca, Raynaliz C. Velazquez

Graduate Thesis and Dissertation post-2024

This thesis investigates 618 ceramic figurines from the Lower Río Verde Valley in Oaxaca, Mexico, to explore how figurine use varied across civic-ceremonial, domestic, and outlying contexts during the Terminal Formative and Late Classic periods. The central hypothesis proposes that figurines from the Río Viejo Acropolis, a civic-ceremonial center, would be larger and exhibit greater labor investment than those from residential and peripheral sites, reflecting more labor-intensive ideologies and ceremonial practices. Through typological, spatial, and material analysis, the study examines attributes such as size, surface treatment, production method, and the presence of musical elements. The dataset includes newly analyzed figurines …

Bim-Based Machine Learning Surrogate Models For Energy And Carbon Prediction To Support Leed Certification Evaluation, Liliane Magnavaca De Paula

Graduate Thesis and Dissertation post-2024

This research developed and validated a Building Information Modeling (BIM)-based Machine Learning (ML) framework for predicting the energy and carbon performance of office buildings during early design stages. The study addresses the need for reproducible data-driven methods supporting sustainable design decisions with reduced simulations time. The proposed approach integrates Revit and Insight with statistical modeling in Weka, creating an automated, transparent, and regionally adaptable workflow for energy and carbon prediction from a BIM-generated data. A reduced-factorial Design of Experiments (DOE) guided the generation of 260 parametric Insight simulations, including base, generalization, and stress-test models distributed across six U.S. climate zones. …

Exploring The Experience Of Heart Disease Among Burmese Immigrants In The United States, Khup S. It

Graduate Thesis and Dissertation post-2024

The ongoing political and military turmoil in Myanmar has resulted in a significant increase in the migration of Burmese individuals to the United States in recent years. This demographic shift has brought attention to the health challenges faced by Burmese immigrants, particularly with regard to heart disease (heart attack). The complexities of the U.S. healthcare system, compounded by legal and social barriers, place immigrants at greater risk for health disparities. This study examines the health challenges of Burmese immigrants in Tulsa, Oklahoma, with a specific focus on their perceptions and experiences related to heart disease, as explored through illness narratives. …

An Integrated Approach To Waste Management And Development Of Data Driven Decision Support Tools, Mert Gokgoz

Graduate Thesis and Dissertation post-2024

Municipal solid waste management requires balancing environmental performance, operational efficiency, and community participation. Proper recycling contamination in single-family units is a persistent barrier to material recovery, reducing the effectiveness of local programs by increasing recycling contamination. This dissertation develops an integrated, data-driven framework that combines behavioral modeling of communities via statistical analysis and machine learning (ML), and life cycle assessment (LCA) to support decision-making in residential waste management. The first component examines household recycling behavior using data from Orange County, Florida’s Recycling Quality Improvement Program (RQIP). Cart-tagging results were integrated with socio-demographic data from the U.S. Census to predict contamination …

Shock Tube Droplet Breakup Experiments Facilitated By Acoustic Levitation, Anthony J. Aguilera

Graduate Thesis and Dissertation post-2024

Droplet introduction methodology in a shock tube differs based on the experimental conditions. For experiments in which the objective is to image droplet breakup, acoustic levitation allows for a consistent droplet shape and for diagnostic equipment to be aligned to a droplet prior to an experiment. A levitator was designed and used in the University of Central Florida’s shock tube facility. Polystyrene doped droplets were levitated to increase the likelihood of cavitation occurring. Multiple droplets were impacted by a shock wave, and the breakup regime was captured using a high-speed camera.

Robust Low-Rank Tensor Discriminant Analysis With Optimal Scoring, Kyle Brinker

Graduate Thesis and Dissertation post-2024

Robust discriminant analysis with optimal scoring has been shown effective for classifying high-dimensional matrix data, particularly in the context of two-dimensional images. The proposed method presents an extension of the Multi-Projection Optimal Scoring Discriminant Analysis framework introduced by Huang \& Zhang (2020), incorporating low-rank Tucker decomposition and regularization techniques to address higher-dimensional cases. The enhanced method is designed to effectively handle tensor-structured data, which is prevalent in imaging applications. The model creates a sparse discriminant projection tensor B that captures class-specific features, such as ball-like patterns in image data and indicators of Alzheimer’s disease in Magnetic Resonance Imaging (MRI) scans. …

Optimizing Emissions And Sustainability Of Alternative Fuel Buses Using Machine Learning And Life-Cycle Modeling, Md Rezwan Hossain

Graduate Thesis and Dissertation post-2024

Public transportation is undergoing a critical transition as agencies seek to balance environmental responsibility, operational efficiency, and economic viability. Alternative fuel buses (AFBs), including electric, compressed natural gas (CNG), propane, and biodiesel, offer opportunities to reduce emissions and advance sustainability, yet their adoption raises complex trade-offs. High upfront costs, infrastructure constraints, range limitations, and variable real-world performance complicate decisions for fleet managers and policymakers. This dissertation addresses these challenges by integrating real-world operational data, life-cycle modeling, and machine learning within a multi-objective optimization framework to evaluate and optimize AFB deployment. Using detailed telematics and GPS datasets from Central Florida's transit …

Design Tool For Ammonia Cracker Hardware, Andrew Menendez

Graduate Thesis and Dissertation post-2024

Ammonia is a promising carbon-free fuel for commercial aviation and represents a viable pathway toward net-zero emissions. However, direct ammonia combustion is inefficient, creating the need for onboard cracking to generate hydrogen for improved combustion characteristics. One pathway for onboard cracking is to have the hardware live around the combustor liner where heat generated from the combustion process can be used to sustain the reaction. This study aims to develop a design tool for the ammonia cracking reactor hardware. A simplified, single-step surface reaction mechanism was implemented using ANSYS FLUENT and CHEMKIN PRO R1, demonstrating strong agreement with experimental data …

Smart Urban Air Pollution Management Using Crowdsourced Big Data, Low-Cost Sensor Network And Aerial Remote Sensing, Md Hasibul Hasan

Graduate Thesis and Dissertation post-2024

Air pollution remains one of the most pressing environmental and public health challenges, especially in urban areas with dense populations and concentrated emission sources. Effective air quality management requires accurate information on emissions to guide control strategies and reliable exposure estimates to evaluate health impacts. This dissertation examines multiple sources of uncertainty in both emission and exposure assessments. Two major emission sectors were investigated: on-road motor vehicles and landfills. For on-road sources, detailed traffic information inferred from crowdsourced big data were leveraged to improve the estimation of traffic-related emissions. For landfills, the application of low-cost sensor and aerial remote sensing …

Towards Achieving General Video Understanding, Rohit Gupta

Graduate Thesis and Dissertation post-2024

This dissertation investigates the problem of general video understanding, aiming to develop models capable of robust, adaptable, and semantically rich interpretation of video data across diverse domains and tasks. Despite significant progress in video analysis, existing methods remain limited by restricted vocabularies, inadequate fine-grained discrimination, and vulnerability to noise and adversarial perturbations. To address these challenges, the research advances four complementary directions encompassing multimodal fusion, open-vocabulary recognition, robustness enhancement, and unified video–language modeling. First, a multi-modal prototype contrastive framework is proposed for fine-grained video classification, integrating visual and auditory cues through a transformer-based architecture and supervised contrastive learning with class …

Paleoethnobotany And Starch Grain Residue Analysis Collected From Ceramics At The White Marl Site, Jamaica, Lydia E. Kiernicki

Graduate Thesis and Dissertation post-2024

The White Marl site represents the largest known Taíno settlement and archaeological site in Jamaica. Road construction in the eighteenth century first disturbed the site, followed by further damage during Mandela Highway construction in the 1940s. The site now faces renewed threats from a proposed highway expansion that has divided it into two zones. In response, the Jamaica National Heritage Trust began archaeological investigations in 2016 to assess and document the land before development and preserve any recoverable material remains and cultural heritage. Field seasons from 2016 to 2019 recovered of several ceramic burial vessels from inhumation contexts, providing valuable …

Advancing Drug Discovery With Structural And Representation Learning Of Biological Systems, Mehdi Yazdani-Jahromi

Graduate Thesis and Dissertation post-2024

The rapid emergence of global health crises, exemplified by the Coronavirus Disease 2019 (COVID-19) pandemic, underscores the profound limitations of conventional drug discovery methods, which are inherently protracted and resource-intensive. A robust, accelerated response framework demands the sophisticated deployment of Artificial Intelligence (AI) and Machine Learning (ML) across the entire therapeutic pipeline. We propose a unified approach centered on \textbf{Structural and Representation Learning} to capture the intricate topological and chemical nuances of biological systems, thereby transforming complex molecular and genomic data into effective vector embeddings suitable for deep learning, enhancing predictive power, and crucially, interpretability. This dissertation details advancements across …

Addressing Vulnerabilities And Defesne Mechanisms In Transformer-Based Language Models, Mansour Al Ghanim

Graduate Thesis and Dissertation post-2024

Transformer-based Large Language Models (LLMs) have achieved remarkable success across Natural Language Processing (NLP) tasks, yet their increasing adoption has exposed critical vulnerabilities across input, model, and output layers. This dissertation systematically investigates these vulnerabilities and develops corresponding defenses, offering an end-to-end view of LLM security. First, we study model-level vulnerabilities through backdoor injection attacks that implant hidden malicious behaviors via hardware perturbations. We propose TrojBits, a hardware-aware attack that uses minimal bit-flips to insert trojans into models. Its three-stage design—Vulnerable Parameter Ranking, Hardware-Aware Attack Optimization, and Vulnerable Bit Pruning—success- fully compromises BERT and XLNet using only 64 parameters and …

Modeling A Moving Manipulator Platform In Ros 2 For Space Robotics, Bastian S. Weiss

Graduate Thesis and Dissertation post-2024

The control of mobile manipulators presents a unique challenge as the complexity of motion increases. ROS 2 provides the ability to create a digital twin of a physical system and control both simultaneously. This can be applied to mobile manipulators, allowing us to plan out complex movements and then simulate them virtually or physically. The Space ROS software is adapted for our Rapid Orbital Motion Emulator which is a 6 Degree of Freedom manipulator on top of a holonomic mobile base platform. Our custom Omni wheel controller running within the ROS 2 control package handles the kinematics for the base, …

Analysis Of An Aero-Engine Using Ammonia As A Fuel Carrier, Kangana Patel

Graduate Thesis and Dissertation post-2024

Numerous studies in the literature have explored the decarbonization of aviation. Some opt for sustainable aviation fuels (SAF), while others propose Hydrogen(H₂). Recent studies have also investigated Ammonia (NH₃) as a potential hydrogen fuel carrier. This study of NH₃ as a viable alternative fuel could help reduce overall emissions and overcome the challenges of H_2, which is highly flammable and difficult to store. This study aims to develop a core-engine model in a system simulation software called Simcenter Amesim. Results show a reasonable similarity between jet-A fuel and NH₃ cracked H₂ within …

Large Language Models And Networks: Edge Proposal, Synthetic Corpora, And Adaptive Node Generation, Nathan Gonzalez

Graduate Thesis and Dissertation post-2024

Natural Language Processing (NLP) and Artificial Intelligence (AI) have evolved from brittle rule-based engines through data-driven statistical models to today’s transformer architectures whose multi-head attention enables rich contextual reasoning. Against this backdrop, this dissertation unifies three complementary investigations that deepen our understanding of how large language models (LLMs) can reason over, generate, and strategically adapt language within networked settings. First, instruction-tuned LLMs are recast as latent-relationship detectors: by prompting models to hypothesize links between text-described entities, we recover edge sets that reconstruct social, thematic, and citation graphs with high precision, revealing how attention distributions encode topological cues. Recognizing the difficulty …

Performance Analysis Of A Turbofan Intergrated With An Entropy-Minimized Heat Exchanger For Ammonia-Powered Aviation, Lucas K. Cavalcante

Graduate Thesis and Dissertation post-2024

Ammonia has emerged as a promising aviation fuel due to its carbon-free emissions, well-established production methods, and transportation infrastructure. However, challenges with its slow chemical kinetics and low flame speed necessitate the partial cracking of Ammonia to introduce hydrogen as a combustion promoter. This study addresses these challenges by designing and optimizing a tube bank heat exchanger to transfer heat from the Cooled Cooling Air (CCA) of the High-Pressure Compressor (HPC) to the Ammonia stream, facilitating the necessary cracking. Preliminary heat transfer calculations indicate insufficient heat in the CCA to achieve cracking temperatures, prompting an alternative approach: splitting the Ammonia …

Investigating Algal Toxin Occurrence And Water Quality Correlations In A Freshwater–Estuarine System, Sunday Sam Egon

Graduate Thesis and Dissertation post-2024

Cyanobacterial toxins, particularly microcystin-LR (MC-LR), present persistent risks in freshwater and estuarine environments, especially under flow-regulated system where hydrodynamics and biology interact complexly. This study investigates the occurrence of MC-LR across a lake–estuary water matrixes, sampling 13 sites from Lake Okeechobee through Caloosahatchee canal, river, and estuarine zones from March to September. Water quality parameters including conductivity, temperature, dissolved oxygen, chlorophyll-a, and phycocyanin were measured in situ. The concentration of MC-LR, and nutrients (ammonium, orthophosphate, and nitrite concentrations) were measured in the laboratory. Multivariate correlation, principal component analysis, and multiple regression were employed to determine dominant drivers of toxin occurrence. …

Learning-Based Ethereum Phishing Detection: Evaluation, Robustness, And Improvement, Ahod Alghuried

Graduate Thesis and Dissertation post-2024

Phishing attacks continue to pose a significant threat to the Ethereum ecosystem, accounting for a major share of Ethereum-related cybercrimes. To enhance the detection of such fraudulent transactions, this dissertation develops a comprehensive framework for machine learning-based phishing detection in Ethereum transactions. The framework addresses critical aspects such as feature selection, class imbalance, model robustness, and the vulnerability of detection models to adversarial attacks. By systematically evaluating these key practices, this work contributes to the development of more effective detection methods. The first part of the dissertation assesses the current state of phishing detection methods, identifying gaps in feature selection, …

High-Efficiency Dual Active Bridge Converter With Stacked Secondary Phase For Next-Generation Ai Data Center Power Delivery, Anirudh Ashok Pise

Graduate Thesis and Dissertation post-2024

The rapid electrification of hyperscale AI data centers is accelerating a shift from legacy 48 V distribution ladders to ±400 V high-voltage DC backbones, concentrating residual loss and dynamic stress on a single isolated bidirectional interface. This work presents a high-density Dual Active Bridge with Stacked Secondary Phasing (DAB-SSP) architecture as a scalable GaN-based solution for 48 V–800 V rack-level power conversion. By stacking 400 V secondaries, the topology leverages 650 V GaN devices while satisfying 800 V system requirements, reducing clearance and creepage distances, minimizing magnetic path lengths, and embedding leakage inductance necessary for wide-range zero-voltage switching.

A rigorous …

Mems-Based Airflow Sensor For Apnea Detection Using Time-Of-Flight Technique, Parvin Akhkandi

Graduate Thesis and Dissertation post-2024

Sleep is essential for overall human health, influencing cognitive, emotional, and physical well-being. Respiratory-related sleep disorders, particularly obstructive sleep apnea (OSA), require early detection and effective treatment to prevent serious health complications. This dissertation explores innovative advancements in respiratory monitoring sensor development techniques, aiming to improve the diagnosis and management of sleep disorders. The sensor in this work incorporates a pair of Thin-film Piezoelectric on Substrate (TPoS) MEMS resonators operating at ~25 MHz, embedded in two oscillator circuits where frequency variations reflect changes in temperature and humidity caused by respiratory airflow. By precisely measuring airflow travel time between the resonators, …

Exploring The Genetic Structure And Evolutionary History Of Marine Fish Populations Across Micronesia, Pavithiran Amirthalingam

Graduate Thesis and Dissertation post-2024

Most marine species exist as metapopulations, composed of subpopulations inhabiting patchily distributed habitat. Connectivity among these subpopulations is primarily facilitated by larval dispersal via ocean currents. Understanding patterns of population connectivity is crucial for evaluating metapopulation dynamics and ensuring long-term population stability in managed species. Micronesia, a vast region in the North Pacific with hundreds of islands, is the northern extent for many tropical species and is thought to function as vital stepping-stones between the central and western Pacific. However, limited phylogeographic studies in the region have left significant knowledge gaps regarding metapopulation dynamics. Here I address this knowledge gap …

Advanced Large Language Model Approaches And Natural Language Processing Techniques To Improve Hate Speech Detection Using Ai, Saad Almohaimeed

Graduate Thesis and Dissertation post-2024

The proliferation of hate speech on social networks can create a significant negative social effect, making the development of AI-based classifiers that can identify and characterize different types of hateful speech in messages highly important for stakeholders. While this is a highly challenging problem, recent advances in language models promise to advance the state of the art such that even subtle and indirect forms of hate speech can be detected.

In this dissertation we present a series of contributions that improve different aspects of hate speech classification. We developed THOS, a hate speech dataset consisting of 8.3k tweets. Compared to …

Autoignition Delay Times For Reformate Gas Mixtures From Methane Gas Engines, Matthew Fraze

Graduate Thesis and Dissertation post-2024

Methane slip is a prominent issue in natural gas reciprocating engines that are used in transportation and marine applications. The incomplete combustion that results in methane slip can be resolved with the introduction of hydrogen within the combustion mixture to improve methane oxidation and further enable combustion within the engine crevices where methane has previously remained unreacted. Steam Methane Reforming (SMR) is a common method used to produce hydrogen and can be used to design an onboard device to reduce methane slip from reciprocating engines. The development of this reformer device requires the validation of high-fidelity chemical kinetic mechanisms at …