Digital Commons Network^™

Safe Optimal Control Of Quadrotor Formations Using Multilayer Neural Networks And Continual Learning, Ehsan Soleimani, Irfan Ahmad Ganie, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents an integral reinforcement learning-based optimal formation tracking scheme for multiple quadrotors unmanned aerial vehicles (QUAVs) experiencing nonlinear coupled dynamics and subject to constraints. We use multilayer neural networks (MNN) within an actor-critic framework where the MNN weights are tuned using singular value decomposition (SVD) of the activation function gradient to approximate optimal control policy via backstepping. Additionally, barrier Lyapunov functions (BLF) are introduced to ensure set invariance, thereby maintaining the quadrotors within a defined safety space due to constraints. A novel weight update law for each layer is derived using the HJB approximation error and control input …

Prescribed-Time Nash Equilibrium Seeking For Pursuit-Evasion Game Under Intermittent Control With Undirected/Directed Graph, Lei Xue, Jianfeng Ye, Yongbao Wu, Jian Liu, D. C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This paper studies the prescribed-time Nash equilibrium (PTNE) seeking problem of the pursuit-evasion game (PEG) with second-order dynamics under the intermittent control (IC) strategy. To achieve Nash equilibrium (NE) in a user-defined prescribed-time, a time-varying high-gain function is incorporated into the design. The core challenge lies in applying IC to NE seeking, which complicates the convergence analysis and control design. To address this sticking point, we construct an auxiliary function and propose a Lyapunov function considering second-order dynamics to solve the PTNE seeking problem of PEG. Building upon the results for undirected graphs, we further extend our findings to directed …

Active And Reactive Power Flow Control Of The Dual Active Bridge Converter, Lauryn Morris, Thomas W. Francois, Jonathan Saelens, Oroghene Oboreh-Snapps, Arnold Fernandes, Praneeth Uddarraju, Sophia A. Strathman, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

The Dual Active Bridge (DAB) is a reliable and efficient converter capable of providing bi-directional power transfer and galvanic isolation. An ac-ac DAB can control both active and reactive power flow. The present work introduces a combined feedback/feed-forward current control system, utilizing the calculated and measured converter currents translated into the dq reference frame, to control the output power. The system was simulated in PLECS to demonstrate the control algorithm's ability to track the dq currents and provide the necessary output power.

Fast-Sparse-Spanner: A Practical Algorithm For Constructing Low-Stretch Sparse Geometric Graphs, Fnu Shariful

UNF Graduate Theses and Dissertations

When constructing geometric graphs (vertices are points and edges are line segments connecting point pairs) on pointsets, stretch-factor (worst-case detour between any point pair) is often considered a quality metric. A low stretch-factor (a quantity that is usually > 1) guarantees short paths between all vertex pairs. A geometric graph having a stretch-factor of t is known as a t-spanner. Creating low stretch-factor geometric graphs for large pointsets with a low number of edges is an open problem in computational geometry.

In this work, we have designed and engineered a new simple and practical (fast and memory-efficient) algorithm named Fast-Sparse-Spanner algorithm …

Traffic Safety In Tacoma: A Dual Study On Community Perceptions Of Vision Zero And The Application Of The Safe System Framework, Janeroza W. Matyenyi

UNF Graduate Theses and Dissertations

The city of Tacoma adopted Vision Zero in 2020 and is planning to achieve zero traffic deaths and severe injuries by 2035. As part of its outreach plan to engage the local community, the city of Tacoma’s Vision Zero team surveyed the critical issues affecting traffic safety as perceived by road users. One of the Vision Zero strategies is to implement safer speeds across streets by reducing speed limits that are too high. This study aims to analyze the factors influencing the perceptions of speeding and high-speed limits as safety concerns, analyze narratives from respondents on issues affecting traffic safety, …

Analysis Of Port Traffic Growth For Optimization Of Traffic Flow: A Microscopic Traffic Simulation Study Of Jaxport's Blount Island Marine Terminal, Amy A. Aida

UNF Graduate Theses and Dissertations

To accommodate increasing cargo volumes and remain competitive, ports worldwide are facing growing pressure to expand and modernize their facilities. However, these expansions can place additional strain on land transportation networks, leading to congestion, delays and operational inefficiencies. This study used VISSIM, a microscopic traffic simulation tool, to model and analyze the complex traffic dynamics at the Blount Island Marine Terminal in Jacksonville, Florida, which is currently undergoing expansion.

To account for future traffic conditions, time series analysis was employed to project growth in traffic demand, taking into consideration anticipated expansions in tenant yard facilities, as well as increases in …

Design, Fabrication, & Laboratory Testing Of A Strain Gage Instrumentation System For Marine Applications, Salem C. Homrighausen

UNF Graduate Theses and Dissertations

A strain gage-based instrumentation system was designed and fabricated to measure the moment present at the base of a mock, diesel-engine snorkel for a submerged vehicle designed to operate in the surf zone. Afterwards, a lab experiment was designed and executed to determine the accuracy of the instrument and a 2-dimensional, matrix-vector equation was formulated to relate pairs of voltages, Vx and Vy, to moments, Mx and My for the experiment. Three versions of this model were built. The first model was created using traditional statics equations governing strain, stress, moment, force. The second and third models were built directly …

Dynamics Of Prey-Prey Mutualism With Varying Carrying Capacity And Herd Behavior In The Presence Of Predator, Felix Dela Djokoto

UNF Graduate Theses and Dissertations

This study investigates the dynamics of mutualistic relationships between two prey species in the presence of a predator, by taking into account herding in one species along with the influence of carrying capacities between two prey species. These mutualistic dynamics are presented by constructing two mathematical models, namely an indirect and direct mutualism model. As the strength of the symbiotic relationship increases the indirect model goes through transcritical bifurcation to Hopf bifurcation whereas in the direct mutualism model goes through saddle-node bifurcation to Hopf bifurcation.

Deference And Discretion In Bank Regulation, Heidi Mandanis Schooner

Scholarly Articles

The U.S. Supreme Court’s decision in Loper Bright Enterprises v. Raimondo, which overturned the Chevron doctrine of judicial deference to administrative agencies’ interpretations of federal statutes, will impact future regulatory policy. The shape of that impact is less certain. Using bank regulation as a vantage point, this Article explores how the end of Chevron may influence legislative and regulatory outcomes. Through case studies, the Article contextualizes the impact of Chevron within the bank regulatory regime’s complex ecosystem of technical expertise, political influence, and industry capture. The dismantling of New Deal restrictions on banks’ activities illustrates how Chevron may have …

Précis Of The Edge Of Sentience: Risk And Precaution In Humans, Other Animals, And Ai, Jonathan Birch

Animal Sentience

We often face grave practical decisions that seem to hinge on whether a system is sentient. This family of cases includes invertebrate animals, people who are unresponsive after brain injury, fetuses, neural organoids, and now AI technologies. We must decide what to do despite ongoing disagreement about the nature of sentience. In our state of uncertainty, we should pragmatically transform the question from “Is it sentient?” to “Is it a sentience candidate, an investigation priority, or neither?”. When a system is a sentience candidate, it is negligent to fail to consider precautions. We should instead evaluate precautions for their proportionality …

Virtual Reality-Based Training To Augment Recovery Of Hand Dexterity After Surgery For Degenerative Cervical Myelopathy, Viprav B. Raju, Roxanne Hauer, Mohammad Ghassemi, Anjishnu Banerjee, Derek Kamper, Brian D. Schmit, Aditya Vedantam

Biomedical Engineering Faculty Research and Publications

Degenerative cervical myelopathy (DCM), the leading cause of non-traumatic spinal cord injury, frequently results in impaired hand dexterity. While surgical decompression is the primary treatment, over 40% of patients report residual hand disability after surgery. There are no therapies to restore hand function after surgery for DCM. In this single-arm clinical trial, post-surgical DCM participants (within 12 months after surgery) underwent a 4-week VR training protocol using the Virtual Keyboard system, which promotes practice of finger individuation. Assessments of hand dexterity were performed at baseline (at week 1), post-training (at week 6) and follow-up (at week 10). The primary outcome …

Scoping Review Of Machine Learning Techniques In Marker-Based Clinical Gait Analysis, Kevin N. Dibbern, Maddalena G. Krzak, Alejandro Olivas, Mark V. Albert, Joseph J. Krzak, Karen M. Kruger

Biomedical Engineering Faculty Research and Publications

The recent proliferation of novel machine learning techniques in quantitative marker-based 3D gait analysis (3DGA) has shown promise for improving interpretations of clinical gait analysis. The objective of this study was to characterize the state of the literature on using machine learning in the analysis of marker-based 3D gait analysis to provide clinical insights that may be used to improve clinical analysis and care. Methods: A scoping review of the literature was conducted using the PubMed and Web of Science databases. Search terms from eight relevant articles were identified by the authors and added to by experts in clinical gait …

Precision Haptics For Rehabilitation: Quantifying Directional Bias And Force Threshold Effects On Motor Learning, Conor J. Nolan

UNF Graduate Theses and Dissertations

Hand rehabilitation represents a critical challenge in modern physical therapy, with significant implications for patients' quality of life and functional independence. Despite technological advancements across healthcare, traditional hand assessment methods often rely on subjective measures or lack task-specific biomechanical assessment capabilities. This thesis investigates the effects of haptic force feedback, handedness, and rotation direction on circle-tracing task completion using a within-subjects factorial design with 20 university participants examining varying resistance levels (0.0N, 0.5N, 1.2N) across different movement configurations using a 3D Systems Touch X haptic device with 0.023mm precision. Results demonstrate that moderate haptic force (0.5N) significantly enhanced spatial accuracy …

Fourier Transformation Of Non-Periodic Functions And Its Application In Computed Tomography, Sabrina Hossain

UNF Graduate Theses and Dissertations

Fourier analysis plays an important role in signal processing and imaging applications,

with computed tomography (CT) being a prominent example. CT imaging relies on recon-

structing cross-sectional images of objects from multiple projections, a process deeply rooted

in the mathematical framework of the Fourier series and its extensions. This thesis explores

the mathematical principle behind CT, demonstrating how periodic and non-periodic func-

tions can be decomposed into sinusoidal components to facilitate image reconstruction. We

begin by reviewing the Fourier series and its ability to represent periodic signals, and then

extend this concept to non-periodic functions through Fourier transforms. The connection …

Understanding Fare Capping In Public Transit: Socioeconomic Predictors And Ridership Outcomes, Maige Majuto

UNF Graduate Theses and Dissertations

Fare capping is a transit policy that limits how much a rider pays within a certain period, after which all rides are free for the rest of that period. Fare capping has become a potential strategy to reverse the trend of declining transit ridership, which has been caused by factors like fare increases, service reductions, and shifts in travel behavior. While demographic and socioeconomic characteristics are known to influence ridership, their role in fare capping adoption remains underexplored. This study examines how factors like age, income, race, education, and car ownership affect fare capping adoption at the neighborhood level and …

Assessment And Optimization Of Electric Vehicles Charging Infrastructure: Addressing Accessibility Disparities In Urban And Rural Areas, Dennis B. Bwire

UNF Graduate Theses and Dissertations

The widespread adoption of electric vehicles (EVs) is essential for advancing sustainable transportation systems; however, disparities in the spatial distribution of electric vehicle charging stations (EVCS) present significant challenges for equitable access. This thesis investigates both the inequities in EVCS accessibility and offers a data driven approach for optimizing the siting of future charging infrastructure.

The first part of the study investigates the accessibility of EVCS in rural and urban areas, focusing on how socio-demographic factors influence accessibility metrics. Using geographic information systems (GIS), network analysis, and binary logistic regression, spatial data on EVCS locations and socio-demographic attributes such as …

Investigating The Roles Of Intrinsic Point Defects And Transition Metal Doping In Monolayer And Bulk Tis2, Patrick J. Keeney

UNF Graduate Theses and Dissertations

Within this thesis, the magnetic and electronic properties of various 1T-TiS₂ systems are thoroughly examined using density functional theory (DFT) and scanning tunneling microscopy (STM). Formation energies and electronic implications of intrinsic point defects in bulk TiS₂ and monolayer TiS₂ are analyzed by approximating a computational monolayer of TiS₂ as the surface layer of a bulk sample. This approximation is validated given that intralayer covalent bonding dominates interlayer van der Waals interactions. We conclude that the most energetically favorable intrinsic defects are Ti atoms settling above the outermost S plane and S vacancies. In addition, the …

Rodcast Interaction: A Novel Technique For Dense Virtual Reality Environments, Nevzat U. Demirseren

UNF Graduate Theses and Dissertations

Virtual Reality (VR) technologies continue to grow in popularity and application versatility, yet effective interaction within complex dense environments remains as a critical challenge. In particular, users with low level of VR experience often face decreased accuracy and dissatisfaction selecting occluded objects. A variety of interaction techniques to select and manipulate objects exist, but there is a research gap in understanding what kinds of techniques support users in dense environments. This study evaluates the user performance and preference in such environments. Three interaction techniques are examined in this study: Go-Go Hand, Flower Cone, and a proposed technique called RodCast Interaction. …

Frustrated Quantum Magnetism: The Interplay Of Isotropic And Anisotropic Interactions With Application To Α-Rucl3, Evan M. Wilson

UNF Graduate Theses and Dissertations

We investigate how anisotropic spin interactions, including Dzyaloshinskii–Moriya and Kitaev terms, manifest across quantum spin systems ranging from a single S = 1/2 dimer to molecular spin clusters and layered magnetic materials. Beginning with an exact analysis of the spin dimer, we demonstrate how singlet–triplet mixing induced by Dzyaloshinskii–Moriya interaction directly influences both thermodynamic observables and inelastic neutron scattering spectra. These microscopic fingerprints are then extended to trimer, tetramer, and tetrahedron geometries, where field-induced phase transitions and heat capacity anomalies reveal the interplay between isotropic Heisenberg and anisotropic Kitaev exchanges. In the frustrated zigzag honeycomb lattice, we show that a …

Solar Energy Prediction Using Advanced Hybrid Machine Learning Models, Jelawi A. Alqhtani

UNF Graduate Theses and Dissertations

Accurate short-term forecasting of solar power generation is critical for the reliable and cost-effective operation of renewable-based microgrids, where sudden weather-induced variability can compromise grid stability, battery scheduling, and energy trading decisions. Traditional physical and statistical models struggle to capture the complex non-linear relationships and localized weather effects, while individual deep learning architectures often exhibit systematic biases such as chronic under-prediction of peak generation. This thesis proposes a novel Cross-Feedback Ensemble framework that combines the complementary strengths of Long Short-Term Memory (LSTM), Gated Recurrent Unit (GRU), and one-dimensional Convolutional Neural Network (1D-CNN) models through an iterative cross-feedback mechanism and a …

Continuing Development Of An Unmanned Vehicle For Conducting Scientific And Engineering Operations In The Littoral Zone, Peter S. Bohn

UNF Graduate Theses and Dissertations

The beach and near shore are among the most economically and environmentally important regions on earth, yet they remain poorly understood due to the challenges of surveying the surf zone and obtaining other important data during high-energy events. Traditional methods such as wading surveys, small watercraft, and specialized vehicles like the coastal research amphibious buggy (CRAB) are limited by safety risks, high mobilization costs, and restricted operating windows. The work conducted in this effort addresses these limitations by continuing development of a remotely operated vehicle (ROV) intended to be operational in harsh surf conditions to collect high-resolution bathymetric and hydrodynamic …

Niobium Titanium Nitride Thin Film Deposition, Optimization, And Characterization, Hudson Horne

UNF Graduate Theses and Dissertations

Superconducting thin film devices such as Josephson junctions are a staple of cutting-edge quantum and classical computing architectures. Functional devices require optimized materials with properties suited to the device application; properties like superconducting critical temperature, critical current density, resistivity, and surface roughness are important depending on the intended device application. Niobium titanium nitride (NbTiN), a fcc transition metal nitride, is a promising material for these applications, with a superconducting critical temperature among the highest of the superconductors described by Bardeen, Cooper, and Schreiffer (BCS) theory. NbTiN has excellent mechanical and electrical characteristics and is easily deposited via reactive magnetron sputtering …

Assessment Of Wave Climate Conditions At An Important Historical And Ecological Site Along The Fort George River In Northeast Florida, Ally O. Kasuwi

UNF Graduate Theses and Dissertations

This study investigated wave climate conditions at the Timucuan Preserve in northeast Florida, addressing gaps in previous shoreline erosion research that largely attributed erosion to boat wakes without detailed wave data. Field data were collected using several do-it-yourself water wave gauges. Each data collection event was for approximately one week, with an emphasis on collecting data before, during, and after periods of expected peak wave activity (i.e., holiday weekends and large-scale storms). Data were analyzed in the frequency domain to establish the likely cause of waves. Results suggested that, counterintuitively, watercraft traffic may have produced higher dominant wave periods than …

Connecting Bicyclists And Transit: A Multimodal Routing Tool With Bicycle Facilities Scoring, Raphael Y. Mrema

UNF Graduate Theses and Dissertations

This research develops a comprehensive, data-driven framework for assessing multimodal bicycle accessibility using open-source technologies and real-time routing data. Traditional active transportation studies often depend on proprietary GIS tools and static network datasets, which limit scalability, reproducibility, and integration with live mobility systems. In contrast, this study introduces a Python-based approach that leverages GeoPandas, the Google Maps Directions API, and General Transit Feed Specification (GTFS) data to dynamically evaluate infrastructure quality, operational stress, and multimodal connectivity. The framework was applied to Duval County, Florida, to examine how roadway design, facility type, and transit availability jointly influence bicycle network performance and …

Computational Pangenomics And Machine Learning For Genotype-Phenotype Analysis, Tejaswi Vemuri

UNF Graduate Theses and Dissertations

Phenotypes are the observable characteristics of an individual organism. Predicting quantitative phenotypes from genomic variation remains challenging when causal signals span both local motifs and distal regulatory contexts. Building on Frequented Regions (FRs)—subsequences conserved across genomes and extracted from a pangenome graph generated from a large collection of closely related species—we compare several modeling strategies across 35 Saccharomyces cerevisiae growth phenotypes: Random Forest (RF) on FR counts (called RFCounts), RF on FR sequences, 1D convolutional neural networks (CNN) on FR sequences, Long Short-Term Memory (LSTM) networks on FR sequences, a Genomewide Association Study (GWAS) baseline, and a sequence-based transformer model, …

Microbial Inactivation And Spray Drying For The Recovery Of Single-Cell Protein From Chemically Deconstructed Polyethylene Terephthalate, Reeba Elizabeth Reji

Dissertations, Master's Theses and Master's Reports

Polyethylene terephthalate (PET) is one of the most widely used polymers in plastics packaging. However, the increasing demand for PET has created challenges in waste disposal. Previous research has shown that PET can be deconstructed using ammonium hydroxide (CDPET). Microorganisms capable of utilizing the product as a sole carbon source can be converted to single-cell protein (SCP). A custom microbial inactivation unit was developed to ensure the safety and stability of generated SCP. Our study evaluated the effect of exposure time (45–60 minutes) at 140 °C with the goal of maximizing microbial inactivation. Our findings suggest that microbial inactivation can …

Measuring Occupant Controlled Ventilation And Cooking Frequency To Aid In Modeling Energy Performance Of Northern Michigan Homes, Jacob J. Chizek

Dissertations, Master's Theses and Master's Reports

This research investigates the real-world interplay between energy efficiency and indoor air quality. We explore how home ventilation strategies, heating systems, and weatherization levels in rural homes interact. As part of a larger study on air quality, 17 homes participated in the study. Specifically, this research shows the results and methods for monitoring cooking frequency, kitchen range hood use, and bathroom fan use over two, month-long study periods to build accurate energy and contaminant transport models of homes that were studied. Energy audits to document home characteristics were conducted, including blower door testing and detailed qualitative data regarding the homes’ …

Thermionic Emission Computational Design Of Rare-Earth Hexaboride Cathodes In An Oxygen Environment, Sophia G. Brylinski

Dissertations, Master's Theses and Master's Reports

This project seeks to optimize a rare-earth hexaboride cathode material for thermionic emission Hall-effect thruster in an air breathing electric propulsion system for the very low earth orbit (VLEO). The main atmospheric constituents in VLEO are nitrogen and atomic oxygen. The presence of oxygen causes the Hall-effect thruster cathode to poison, sharply decreasing its electron emission, thus reducing thrust. Two cathodes used for thermionic emission are dispenser cathodes and lanthanum hexaboride (LaB₆) cathodes, with the LaB₆ cathodes having better resistance to oxygen poisoning. It is desired to develop a cathode that can better tolerate the oxygen environment …

Development And Validation Of Novel Force Reconstruction Algorithm For Traction Force Microscopy, Samuel E. Haarman

Dissertations, Master's Theses and Master's Reports

Traction Force Microscopy (TFM) is a powerful technique for quantifying cellular traction forces, yet its accuracy is dependent on the force reconstruction algorithm used to recover traction forces from the input substrate deformations. As such, the use cases of TFM are dependent on the types of reconstruction algorithms available. To expand the usability of TFM onto micropatterned substrates, we introduce gFEM, a novel force reconstruction method that incorporates the specific grooved topography of the user’s experimental substrate into the solution process. Unlike other traditionally used models, which assume a flat and continuous substrate, gFEM aims to improve the fidelity of …

"An Ancient Vanished Race:" Industrial Mythistory And The Alternative Archaeology Of Lake Superior Copper, Donovan C. Murphy

Dissertations, Master's Theses and Master's Reports

This thesis explores how the perspectives, biases, and values of Euro-Americans regarding the copper mining industry have shaped a mythology which centers Lake Superior copper in an imagined pre-Columbian global trade network. Notably, many iterations of this mythology are rooted in a rejection of Indigenous agency in the creation of these sites, ascribing them instead to a ‘vanished race’ which had surely once occupied the region. The core of this thesis is formed around a set of semi-structured interviews with representatives of regional heritage institutions and avocationalists which were conducted with the goal of identifying how and why these stories …