Digital Commons Network^™

A Clustering-Based Approached To Analyze Impacts Of Digital Divide On Undercounting Issues In Census In Florida, Partha Protim Datta

UNF Graduate Theses and Dissertations

According to the US Census Bureau 2020 data, Florida is one of the six states where the population was undercounted. The census in the US is conducted every ten years and plays a pivotal role in shaping government representation, resource allocation, policy making and federal assistance distribution. Consequently, undercounting of population impacts demographic equality, potentially leading to inequitable distribution of resources. The state of Florida will lose billions of dollars by the end of the decade due to this undercounting issue. So, it is an important task to find the proper reason and sources of undercounting in Florida. The US …

Explainable Automated Inconsistency Detection In Biomedical And Health Literature, Prajwol Lamichhane

UNF Graduate Theses and Dissertations

Given the exponential growth of scientific information online, researchers often face the daunting task of detecting contradictory statements on crucial health topics. This work develops a comprehensive pipeline for automated contradiction detection that integrates an Information Retrieval (IR) system, machine learning classifiers, and Explainable AI (XAI). The Information Retrieval system is tailored for biomedical data and comprises a datastore, syntactic, and semantic components. Users can input queries, initiating a pipeline that identifies top documents through syntactic analysis and refines results via semantic examination for relevant research claims. Employing a diverse range of Large Language Models such as pre-trained Distil-BERT, BioBERT, …

Anomaly Detection Approaches Of Energy Storage Systems Using Kalman Filter And Machine Learning Techniques, Phadungsak Tubuntoeng

UNF Graduate Theses and Dissertations

The increasing prevalence of cyber-attacks poses a significant concern, particularly within critical infrastructures like the power system. Such attacks have the potential to cause substantial impacts on essential services, economic stability, and national security. Energy storage systems (ESS) are integral components of the power grid and are particularly vulnerable to cyber threats. These vulnerabilities can be exploited through various means, including two-way communication, web portals, and remote access.

Given the critical nature of ESS, the ability to detect and mitigate malicious cyber-attacks is imperative. Various methods can be employed for cyber-attack detection, including signature-based, anomaly-based, and behavior-based approaches. In this …

Process, Structure, & Property Investigation Of Gallium-Based Metallic Alloys Processed At Room Temperature, Jennifer E. Ruliffson

UNF Graduate Theses and Dissertations

Metallic and intermetallic alloys are important in engineering, necessitating a thorough comprehension of their structure, processing, and properties. Amalgams are a class of alloy which are synthesized by various methods to produce diverse properties. Gallium-based amalgams, particularly gallium eutectic alloys, have low melting points, which allow for applications in dentistry and temperature sensitive electronics. This thesis investigates the process-structure-property relationships of gallium-based amalgams mixed with copper. Phases, microstructure, and diffusion processes are investigated using XRD and SEM. Adhesion strength and thermal properties are then correlated to these as well as process steps. This study contributes to advancing the understanding and …

The Perceptions Of Black Women In Principalships On Navigating And Negotiating The Racial Contexts Of Their Equity-Focused Leadership: A Q Methodology Study, Easter M. Brown

UNF Graduate Theses and Dissertations

One consequence of the Brown v. Board of Education (1954) ruling regarding desegregation of American public schools has been the destabilization of Black educators’ legacy of school leadership (Tillman, 2004). The effects of these failures continues to be problematic in US public education. Students of color account for over half of all P-12 enrollments, in contrast to the disproportionate lack of diversity among its teaching and leadership rosters (Frankenberg, et al., 2019; NCES, 2018, 2022). The stagnant rate at which American schools have diversified principal leadership since Brown v. Board (1954) begs the question of how equipped schools are to …

Processing Of Niti Sma For High Reflectivity Applications, Nicholas Dean Asbury

UNF Graduate Theses and Dissertations

Nickel Titanium (NiTi) is a shape memory alloy (SMA) that is capable of being deformed and subsequently returned to the original shape through heating. This unique property makes NiTi a prime material for potential applications in the aerospace industry. As manufacturing capabilities advance, the ability to produce and implement advanced materials, such as shape memory alloys like NiTi, becomes more feasible. One such application being studied is deployable mirrors for imaging satellites. Reflector and mirror surfaces for imaging in the visible and infra-red range of the light spectrum require low surface roughness across the largest allowable area for the collection …

Laboratory Measurements Of Wave Transmission Through Oyster-Based Low Crested Breakwaters, Michael Andrew Roster

UNF Graduate Theses and Dissertations

Pervious Oyster Shell Habitats (POSH) are novel living shoreline components that were recently developed and deployed along several shorelines in northeast Florida. POSH units are designed to provide a breakwater using only recycled eastern oyster shell and Portland cement. However, the hydrodynamic performance of these unique structures had never been tested, so it was unclear how they affected wave energy. During this study, a series of laboratory experiments were conducted to compare wave attenuation from POSH units to wave attenuation from geometrically similar and commercially available Reef Balls^TM (specifically, the OysterBreak series of units). Experiments included a range of …

Can A Phycosphere Associated Bacterium Be Used As A Biological Control For Floating Algal Mats?, Aubrey C. Patterson Holsworth

UNF Graduate Theses and Dissertations

Abstract

Freshwater harmful algal blooms (HABs) are a global water quality issue. Algae, especially cyanobacteria, are integrally associated with complex microbial assemblages, which cycle nutrients, provide microenvironments, breakdown potentially harmful molecules, etc. However, these same microbial consortia are competitors or even inhibitors to algae in these systems. One potential biological control is Rhodospirillum rubrum, a Gram- proteobacterium. To evaluate its capacity for HAB mitigation, experimental mesocosms were inoculated with a native assortment of algae and R. rubrum and grown for 2-months. Relative Fluorescence Units (RFU), Ash Free Dry Mass, and eukaryotic (23S rDNA) metabarcoding were conducted to estimate algal …

Implementation Of Algorithms For Sorting By Strip Swaps Using Alternating Cycle Graphs, Harsh S. Bhakharia

UNF Graduate Theses and Dissertations

Challenges in computational biology, such as genome rearrangement, and applications in optical character recognition, like zoning techniques, often require solving optimization problems. These involve reordering scrambled sequences of numbers into a sequential arrangement known as the identity permutation.

Rearranging any given permutation into the identity permutation with the minimum number of specific operations related to strips gives rise to various combinatorial optimization scenarios. Operations such as strip moves, transpositions, reversals, and block interchanges have been extensively researched.

This thesis builds on the foundational work of Roy et al., targeting the refinement of their cycle graph algorithm for sorting by strip …

A Method For Investigation Of Small-Scale Morphologic Change Around Low Crested Oyster-Based Structures, Makaya S. Malila

UNF Graduate Theses and Dissertations

In recent years, a novel method for shoreline stabilization, Pervious Oyster Shell Habitat (POSH) units, comprised of recycled eastern oyster shells, has been developed. These mound-shaped structures have been deployed along several shoreline sites in Northeast Florida. This case study sought to develop and implement a method for investigation of small-scale morphologic change in the vicinity of these structures using smartphone LiDAR technology, surveying instruments, and 2D/3D mapping software. Results suggest that the POSH units are helping to mitigate erosion by trapping sediments around them. Moving forward, it may be possible to adapt the methodology used here to assess morphologic …

Gender Equity: The Perception Of Career Advancement In Higher Education, Whitney K. Washington

UNF Graduate Theses and Dissertations

Women have made many strides in many industries, yet a gendered leadership gap still exists. On many college and university campuses, women are the top degree earners, but they are not represented in executive leadership roles in higher education. The purpose of this quantitative study is to examine university staff perception of career advancement by investigating how independent variables—demographics, challenges and barriers, diversity management, career planning, work-life balance, and pay—are related to the dependent variable—careeradvancement. The study explores the perception of career advancement as a factor that may explain the gendered leadership gap. This study answers the following research questions: …

Spatial Equity In Accessing Critical Facilities During Hurricanes, Pooya Komeilian

UNF Graduate Theses and Dissertations

Florida encounters multiple natural disasters every year, making evacuation a critical mitigation plan when severe impacts are predicted. Evacuation is a complex procedure that involves everything from household decision-making to large-scale traffic network analysis. It also addresses logistical issues, such as transporting impacted people to shelters or medical centers. Access to shelters, gas stations, and lodgings is of utmost importance, as numerous studies and surveys have shown that some people prefer not to evacuate, even if they perceive the disaster risk to be very high.

Based on this, the present study follows two phases to address gaps in evacuation studies. …

Integrating Therapy Into Play: Stand-On Ride-On For A Child With Cerebral Palsy, Kira Flanagan

UNF Graduate Theses and Dissertations

This study focuses on the development of an adaptive ride-on toy specifically designed for a 2.5-year-old child with spastic diplegic cerebral palsy. As a feasibility study, the primary objective of this innovative device is to enhance motor function, foster autonomy, and improve the overall quality of life for the child. The Power Mobility Device (PMD) integrates actuation and steering modifications, and a harness mechanism tailored to meet the child's unique needs. Comprehensive assessments of the child's spatiotemporal gait characteristics were conducted before and after a three-month usage period. The results reveal significant improvements in the child's ability to control dynamic …

Factors Influencing Household Travel Behavior And Trip Distances In Florida: A Rural Vs. Urban Perspective, Kadeem Lafargue

UNF Graduate Theses and Dissertations

This thesis investigates disparities in travel behaviors between rural and urban populations in the United States, with a specific focus on Florida. Leveraging data from the 2017 National Household Travel Survey (NHTS), the study examines demographic factors such as age, income, and household size, and their influence on travel patterns. By employing statistical methods including Poisson and negative binomial regression models, the research explores two key variables: the frequency of trips made per day and the average trip distance in miles. These models are particularly effective in handling overdispersion in count data, ensuring a robust analysis of travel behaviors across …

Large Language Models For Multimodal User Interaction In A Virtual Environment, Ahmed A. Sayed

UNF Graduate Theses and Dissertations

Virtual Reality (VR) is increasingly popular, but many barriers exist for individuals with little experience in coding, 3D modeling, or creating their own virtual experiences. The current tools used for content creation are often viewed as complex or frustrating, and they exhibit a steep learning curve. This problem presents an opportunity to develop tools incorporating Natural User Interfaces that better support end users. One such possible tool to assist users is Large Language Models (LLM), which can, extract a user's intention through speech or text. We posit how using LLMs can better support novice and expert developers alike, and using …

A New Perspective On Teacher Attrition And Retention: What Can Be Learned From Teachers That Continue In The Profession, The Stayers?, Haley M. Vogel

UNF Graduate Theses and Dissertations

This phenomenological research study focuses on closing the divide between ongoing teacher shortages created by labor market cycles and teacher attrition with retention practices that keep qualified teachers in K-12 public schools. The literature review of this study identified a gap in research related to teacher shortages. Significant research exists around why teachers leave the profession, however, research related to why teachers stay is limited. The purpose of this phenomenological study was to better understand the lived experiences (Moustakas, 1994, van Manen, 2023, Creswell & Poth, 2018) of K-12 secondary public-school teachers continued decision to remain in the profession. The …

Media Haze Classification In Retinal Images Using Deep Learning, Jonathan O'Berry

UNF Graduate Theses and Dissertations

Media Haze (MH) is a condition that affects an individual’s quality of life by affecting their eyes. Current practice is to detect MH by manually examining retinal fundus (retinal) images. The analysis of images being used as the prevalent technique for identifying the MH condition strongly suggests that automation of this process may be possible. In recent years, machine learning, specifically computer vision, has allowed for the automation of tasks relating to image analysis. This ability to automate has also recently been shown in the medical field for some eye conditions and diseases. This thesis centers around the problem of …

Exploring Parental Engagement In A Family Stem Program Leveraging Social Media Spaces, Valentina Bongiovanni

UNF Graduate Theses and Dissertations

The Family Take-home STEM Toolkit Program offers families the opportunity to engage in science, technology, engineering, and mathematics (STEM) learning by utilizing the informal environments of the home and program-dedicated social media groups. This initiative provides a frame for this research, as parental engagement in the context of this early childhood program is explored through the lens of the Ecologies of Parental Engagement (EPE). This theoretical model understands engagement as the mediation of space and capital (Barton et al., 2004) and guides this study to further explore parental perceptions concerning the social media space activated with the STEM Toolkit Program. …

Influence Of Heat Treatment And Shielding Gas Environment On The Very High Cycle Fatigue Behavior Of 17-4 Precipitation Hardened Stainless Steel, Jade Welsh

UNF Graduate Theses and Dissertations

Additive manufacturing (AM) for stainless steel components has proved useful in a variety of industries ranging from aerospace to biomedical engineering. Many of these components are subject to very high cycle fatigue (VHCF) loading and must have tailored mechanical properties to ensure failures do not occur before a service life is reached. Testing the fatigue strength AM materials exposed to VHCF loading is paramount to compare with the expected life cycles of their wrought counterparts. In this thesis, AM 17-4 precipitation hardened (PH) stainless steel (SS) were fabricated using laser powder bed fusion (L-PBF) technique, while the wrought 17-4 PH …

Robotic Gas Source Localization And Distribution Mapping Via Deep Reinforcement Learning, Iliya Kulbaka

UNF Graduate Theses and Dissertations

This research aims to advance the fields of Gas Source Localization (GSL) and Gas Distribution Mapping (GDM) by developing deep reinforcement learning (DRL) methodologies suitable for complex, real-world environments. GSL and GDM are crucial for applications such as environmental monitoring, hazardous material detection, and search-and-rescue missions, where safe and efficient exploration is essential. Traditional methods often fall short in dynamic settings influenced by factors like wind and obstacles. To address these limitations, this study proposes novel neural network architectures and learning frameworks for adaptive exploration and mapping, integrating Convolutional Neural Networks (CNN), Long Short-Term Memory (LSTM) layers, and Deep Q-Networks …

Passperfect: A Secure One Time Password Authentication System, Charlene H. Crawshaw

UNF Graduate Theses and Dissertations

Most organizations have established strong password policies and standards to ensure the confidentiality, integrity, and availability of their data, applications, and critical systems. Even with rigorous implementations and layered approaches such as utilizing multifactor authentications, there are still flaws and vulnerabilities as they have a high dependency on the user adhering to them. In conjunction with these policies, a strong security awareness program should be implemented to educate the end user about strong password hygiene. In this work, we design and implement a secure one-time password (OTP) system, “PassPerfect”, to provide a method of enforcing a strong set of password …

Assessing Unoccupied Aircraft And Ground-Based Methods For Detecting Differences In Intertidal Oyster (Crassostrea Virginica) Reef Structure, Alyah Bennett

UNF Graduate Theses and Dissertations

Eastern oyster (Crassostrea virginica) reefs provide critical ecosystem services, including shoreline stabilization, water filtration, and habitat for diverse marine species. However, these reef habitats are declining globally due to overharvesting, disease, and environmental change. This study evaluated the effectiveness of in-situ vs drone-based methods for detecting differences in oyster reef structure focusing on percent live cover and rugosity as key indicators. We also compared these methods in terms of cost, effort, and variability. Using data collected from Northeast Florida on a variety of reef types exposed to various disturbances, we developed generalized linear models to evaluate for differences …

Analysis Of Shoreline Erosion At Cumberland Island Using Advanced Circulation (Adcirc) Modeling, Christopher Harrigan

UNF Graduate Theses and Dissertations

This study investigates shoreline erosion at Brickhill Bluff along the Brickhill River in Cumberland Island National Seashore using ADCIRC. Two scenarios were modeled during this research: bed stresses during regular tidal cycles and bed stresses during worst-case storm (i.e., hurricane) conditions. Velocities from these models were used to compute bed shear stresses and these stresses were compared to site’s sediment critical shear stress. Results appear to show that a meander in the Brickhill River causes relatively high (i.e., on the order of 0.27 ��/��² ) shear stresses during regular tidal cycles and even higher (i.e., on the order of …

An Enhanced Evaluation Of Bioslurry For Use In Coastal Erosion Mitigation, Megan Elizabeth Dunton

UNF Graduate Theses and Dissertations

This paper discusses the treatment of Florida beach sand by surface percolating Bioslurry, a microbially-induced calcite precipitation (MICP) variant that was developed and refined in recent years. Researchers examined how variations in pore volume and surface area affected the cemented depth of soil treated via surface percolation. Results suggested that while the pore volume is an important factor that governs cementation in soil treated via surface percolation, it does not appear to be the only controlling factor and treatment volume per unit surface area is another important factor to consider when treating soil with Bioslurry using surface percolation. The implications …

Understanding And Augmenting Scientific Software Testing Practices, Kris Roker

UNF Graduate Theses and Dissertations

Scientific software can be broadly defined as software written to aid in conducting scientific research activities. As this software is often written by the scientists themselves, who often learned programming to build that software, some important aspects of software development may get less attention than they would have gotten on enterprise software developed by programmers. One area of development that often gets overlooked in this regard is testing. Thus, in this study, we seek to better understand the testing processes and propose methods to improve the effectiveness of those tests. We begin with examining the software's Continuous Integration/Delivery practices. This …

Development And Characterization Of Ceramic Devices For Capillary Action In Microgravity For The Purpose Of Growing Vegetables In Space, Lucas S. Mougeot

UNF Graduate Theses and Dissertations

The future of humanity is often rendered in spectacular visions of a multiplanetary civilization with a booming space economy. Reaching this reality requires addressing one of the core needs of survival: food. Porous ceramics used for Passive Porous Tube Nutrient Delivery Systems (PPTNDS) offer a promising solution. In microgravity environments such as the International Space Station (ISS), fluid dynamics and liquid coagulation do not support conventional agricultural practices. Porous ceramic materials present a solution that enables nutrient solution diffusion via capillary action.

In this research, it was determined that extruding a wadding ceramic tube and sintering it at 1900 °F …

Breach Of Faith: The Special Problem Of Osha Performance Standards, Marshall J. Breger, Arthur G. Sapper

Scholarly Articles

This Article focuses on a special problem with performance standards - that their performance criteria are often so subjective as to deny regulated persons a clear idea of what is required. It begins with a discussion of specification and performance standards in American regulatory history. It further discusses attempts by Congress and others to, therefore, require that performance criteria be “objective.” The Article then sets out a case study of how congressional attempts to require “objective” performance criteria have fared. It examines in depth whether one agency, the Occupational Safety and Health Administration (OSHA), has complied with that special requirement …

Gamma Amplitude-Envelope Correlations Are Strongly Elevated Within Hyperexcitable Networks In Focal Epilepsy, Manoj Raghavan, Jared Pilet, Chad Carlson, Christopher T. Anderson, Wade Mueller, Sean Lew, Candida Ustine, Priyanka Shah-Basak, Vahab Youssofzadeh, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Methods to quantify cortical hyperexcitability are of enormous interest for mapping epileptic networks in patients with focal epilepsy. We hypothesize that, in the resting state, cortical hyperexcitability increases firing-rate correlations between neuronal populations within seizure onset zones (SOZs). This hypothesis predicts that in the gamma frequency band (40–200 Hz), amplitude envelope correlations (AECs), a relatively straightforward measure of functional connectivity, should be elevated within SOZs compared to other areas. To test this prediction, we analyzed archived samples of interictal electrocorticographic (ECoG) signals recorded from patients who became seizure-free after surgery targeting SOZs identified by multiday intracranial recordings. We show that …

Designing A Use-Error Robust Machine Learning Model For Quantitative Analysis Of Diffuse Reflectance Spectra, Allison Scarbrough, Keke Chen, Bing Yu

Biomedical Engineering Faculty Research and Publications

Significance

Machine learning (ML)-enabled diffuse reflectance spectroscopy (DRS) is increasingly used as an alternative to the computation-intensive inverse Monte Carlo (MCI) simulation to predict tissue’s optical properties, including the absorption coefficient,μaand reduced scattering coefficient, μs′.

Aim

We aim to develop a use-error-robust ML algorithm for optical property prediction from DRS spectra.

Approach

We developed a wavelength-independent regressor (WIR) to predict optical properties from DRS data. For validation, we generated 1520 simulated DRS spectra with the forward Monte Carlo model, where μa=0.44 to 2.45cm−1, and μs′=6.53 to 9.58cm−1. We introduced common use-errors, such as wavelength miscalibrations and intensity fluctuations. Finally, we …

Investigation Of Operational Parameter Differences Between The Standard Ron Test Method And Knock-Limited Modern Spark-Ignition Engine Operation, Alexander Hoth

Dissertations, Master's Theses and Master's Reports

Octane numbers (ONs) are used worldwide to rate the knock propensity of gasoline-like fuels for spark-ignition engines, making ONs the leading indicator of fuel quality for commercial distribution. The ONs were established 90 years ago and have only received minor changes compared to significant advancements in modern engine operation and fuel composition. This has resulted in discrepancies between knock-limited modern engine operation and standard ON ratings. This dissertation used a standard CFR octane rating engine at Argonne National Laboratory that was instrumented with modern combustion research tools to investigate key differences between the Research Octane Number (RON) rating conditions and …