Digital Commons Network^™

Brain-Inspired Spatio-Temporal Learning With Application To Robotics, Thiago André Ferreira Medeiros

USF Tampa Graduate Theses and Dissertations

The human brain still has many mysteries and one of them is how it encodes information. The following study intends to unravel at least one such mechanism. For this it will be demonstrated how a set of specialized neurons may use spatial and temporal information to encode information. These neurons, called Place Cells, become active when the animal enters a place in the environment, allowing it to build a cognitive map of the environment. In a recent paper by Scleidorovich et al. in 2022, it was demonstrated that it was possible to differentiate between two sequences of activations of a …

Integration Of Algae And Biomass Processes To Synthesize Renewable Bioproducts For The Circular Economy, Jessica Martin

USF Tampa Graduate Theses and Dissertations

Rapid population growth and global industrialization have substantially heightened the demand for fossil-based fuels and products in various sectors of the global economy, including energy production, transportation fuels, and as raw materials for petrochemicals. The intense consumption of fossil fuels has caused immense environmental impacts, especially pertaining to carbon dioxide emissions. Shifting to renewable feedstocks (raw materials) is expected to reduce these emissions by lowering the carbon footprint of fuels and products compared to traditional fossil-derived alternatives. This transition aligns with the goal of creating a sustainable and circular economy, emphasizing efficient resource use, and reducing waste generation through recycling …

Swelling Induced Buckling Of Photopatterned Hydrogel Beams, Chinar Yogesh Kokaje

USF Tampa Graduate Theses and Dissertations

The main goal of this study was to learn more about swelling induced buckling of surface-attached gel lines photo-patterned from thermally responsive polymers. A library of 10 different polymer compositions was synthesized using methacryloyloxybenzophenone (MABP) as the photo-cross-linking monomer. For each of the polymers, a series of beam-like patterns were prepared on polystyrene tissue culture dishes by first depositing a known amount of polymer into the tissue culture dish followed by pattern generation using a photo-lithography mask with line widths of 10, 20, 30, 50, and 80 μm. The target height of each polymer line was 100 μm. After development …

Syntheses, Photophysics, & Application Of Porphyrinic Metal-Organic Frameworks, Zachary L. Magnuson

USF Tampa Graduate Theses and Dissertations

Porphyrins are a group of heterocyclic macrocycles that play crucial roles in various biological processes such as electron transfer, catalysis, and sensing. Hemoglobin, which carries oxygen in the blood of mammals, and chlorophyll, which drives photosynthesis in plants and algae, are both porphyrins. The ability of porphyrins to bind metal ions and their unique electronic and photophysical properties make them an excellent platform for designing functional materials for various applications, often drawing inspiration from their function in nature. Metal-organic frameworks (MOFs) are a class of porous materials that have been extensively studied in recent years due to their high surface …

Mechanisms Contributing To Hydrogen-Influenced Early Failure Of Bridge Tendons, David Dukeman

USF Tampa Graduate Theses and Dissertations

Failures in post-tensioned tendons have occurred without warning due to fractures in the high-strength steel strands. These strands are cold-drawn to increase their strength while still retaining the preferential ductile mode of fracture. Recently, a tendon failure that occurred in an upper deviation block of the I-526 James B. Edwards bridge crossing the Wando river showed signs of corrosion and potentially another method of failure, hydrogen embrittlement. One proposed source of hydrogen is through galvanic coupling that may exist between the galvanized steel duct and the steel strands. This coupling, if substantial, can promote hydrogen evolution at the steel strand's …

Interdependency Between Water And Road Infrastructures: Cases And Impacts, Shihab Uddin

USF Tampa Graduate Theses and Dissertations

This dissertation studies the interdependency between road and water infrastructures and associated interdependency impact on these two critical infrastructure systems. Critical infrastructures and the interdependency among these infrastructures have gained much attention recently because of its growing complexity, importance, and vulnerability to natural and man-made threats. In response, researchers have spent significant effort to study these infrastructures individually as well as when they are interdependent to understand complex interdependency relationship and to figure out ways to make these infrastructures more reliable, robust, and resilient. However, water and road infrastructure systems have not been studied as vastly as other critical infrastructures …

Novel Systems Engineering Framework Analysis Of Photovoltaic Models And Equations, Peter R. Michael

USF Tampa Graduate Theses and Dissertations

This dissertation analyzes Photovoltaic PV equations and models for silicon based systems from a Systems Engineering framework. Background information includes an introduction, a summary of the state of PV use, a brief history of photovoltaics, and the detailed derivation of equations that enable the finding of the PV parameters contained in the PV models.The novel inquiry, leveraging systems engineering frameworks, includes three areas useful in analyzing PV equations and models. The first is a statistical verification of common simplifications of PV equations at the primary conditions of short circuit, open circuit, and maximum power. Additional analysis shows other simplifications that …

Deep Learning-Based Automatic Stereology For High- And Low-Magnification Images, Hunter Morera

USF Tampa Graduate Theses and Dissertations

Quantification of the true number of stained cells in specific brain regions is an important metric in many fields of biomedical research involving cell degeneration, cytotoxicology, cellular inflammation, and drug development for a wide range of neurological disorders and mental illnesses. Unbiased stereology is the current state-of-the-art method for collecting the cell count data from tissue sections. These studies require trained experts to manually focus through a z-stack of microscopy images and count (click) on a hundred or more cells per case, making this approach time consuming (~1 hour per case) and prone to human error (i.e., inter-rater variability). Thus, …

Wastewater Treatment Using Encapsulated Chabazite In Polyvinyl Alcohol-Sodium Alginate Hydrogel Biofilm Carriers, Susieanna Nevada Persaud

USF Tampa Graduate Theses and Dissertations

Nitrogen discharge from wastewater is a global issue and with increased urbanization as well as industrialization, it has become even more essential to develop more efficient wastewater treatment systems. The dominant form of nitrogen in wastewater is ammonium. Biological oxidation of ammonium to nitrite and nitrate is the first step in biological nitrogen removal processes. If left untreated, nitrogen can cause toxicity to aquatic life, unsafe changes in water quality, and eutrophication.

Biofilm carriers can help to improve the efficiency of traditional activated sludge wastewater treatment systems by reducing operating costs and reducing hydraulic retention time. Biofilm carriers also promote …

Hurricanes And Tropical Storms’ Impact On Water Quality In Lake Okeechobee, Florida, Daniela Vasquez Diaz

USF Tampa Graduate Theses and Dissertations

Hurricanes are natural events with catastrophic outcomes, while climate change's effects on their intensity and frequency remain discussed. However, it is crucial to analyze these through models and statistics to understand their behavior and impact on the basins. Particularly in lakes on tropical coasts since disruptive events such as hurricanes tend to be highly affected. Lake Okeechobee is a unique lake located in Florida and one of the largest freshwater lakes. The lake and some of its significant stations are the locations chosen to perform the investigation. The main focus of the investigation is determining the effect that hurricanes have …

Analyzing Multi-Robot Leader-Follower Formations In Obstacle-Laden Environments, Zachary J. Hinnen

USF Tampa Graduate Theses and Dissertations

Observations in biological formation from nature likes flocks of birds, herds of mammals and packs of wolves have inspired the innovation of robotic architectures. This thesis presents an approach that aims to use robotic systems to mimic leader-follower behaviors in the navigation and formation of sparse and dense environments. The goal of this work is to extend and further analyze the original work of Weitzenfeld et al [3] to evaluate new swarm and pack based multi-robot architectures with the inclusion of obstacle avoidance and variations in group formations. The multiple robot architecture is based off a wolf pack with a …

Knowledge Integration In Domain-Informed Machine Learning And Multi-Scale Modeling Of Nonlinear Dynamics In Complex Systems, Phat K. Huynh

USF Tampa Graduate Theses and Dissertations

Nonlinear dynamical systems have been extensively used to model various phenomena in the changing world around us, especially in science and engineering fields. Thanks to breakthrough advancements in sensing technologies, an increasingly high volume of multi-modal sensor data has been collected, which enables us gain better insights into complex systems dynamics and build sophisticated data-driven machine-learning-based dynamic models without having the access to the underlying governing equations. However, integrating domain-specific knowledge in machine learning algorithms remains pivotal for various reasons: it promises enhanced predictive accuracy, better model interpretability, and increased generalizability. This dissertation delves into three core research questions, each …

Effects Of Downdrag On Pile Performance, Ruthvik Pendyala

USF Tampa Graduate Theses and Dissertations

The behavior of piles under varying load conditions has sparked significant interest and research within the geotechnical engineering field. Specifically, in the context of MSE wall-type embankments, piles are installed before embankment construction commences. In these scenarios, soil settlement beneath the embankment initiates following pile installation, consequently generating downward lateral shear loads on the piles, known as downdrag.

Research pertaining to the downdrag phenomenon in cohesionless granular soils is limited. Hence, the primary focus of this study revolves around examining the impact of downdrag on pile performance in sandy soils using numerical modeling as the investigative approach. To accomplish this, …

The Development Of A General Watershed - Highway Mathematical Model, Robert W. Higgins

USF Tampa Graduate Theses and Dissertations

No abstract provided.

The Aging Workforce: How It Relates To Incident Rates Within A Distribution Warehouse And A Chemical Manufacturing Building, Elisabeth V. Jones

USF Tampa Graduate Theses and Dissertations

Over the past 20 years or so, the average age of the global population has slowly increased. This is due to low birth rates as well as increased life expectancy. With this global population aging, there has also been a shift in the global labor market causing a trend termed the “aging workforce.” However, with the aging workforce comes a new set of issues for the health and safety professional because they create new hazards. This is due mostly because of the body undergoing physical, psychological, and cognitive decline as someone ages which causes decreased capabilities. Thus, the purpose of …

Cyber-Physical Multi-Robot Systems In A Smart Factory: A Networked Ai Agents Approach, Zixiang Nie

USF Tampa Graduate Theses and Dissertations

This dissertation focuses on addressing the technical challenges of non-stationarity in smart factories through the use of cyber-physical AI agents. Industry 4.0 and smart manufacturing with smart factories as a central role, have a growing demand for Just-in-Time (JIT) and on-demand production, as well as mass customization—all while maintaining high productivity, resource efficiency and resilience. This research positions Multi-Robot Systems (MRS)-driven smart factories. The heterogeneous production and transportation robots in an MRS collaborate to form multiple real-time adjusted production flows achieving the flexibility to accommodate such on-demand, mass customization.

However, the implementation of MRS introduces new sets of challenges, including …

Exploration Of Shared Passenger Urban Air Mobility – Integrated Network Design, Operation Scheduling And System Configuration, Zhiqiang Wu

USF Tampa Graduate Theses and Dissertations

Urban air mobility (UAM) is an emerging concept proposed in recent years that uses electric vertical take-off and landing vehicles (eVTOLs). UAM is expected to offer an alternative way of transporting passengers and goods in urban areas with significantly improved mobility by making use of low-altitude airspace. Considering the high capital investment of eVTOLs and relative high fee of using UAM passenger service, a viable UAM format is shared passenger service. Such a service is usually station-based, i.e., with vertiport located in popular sites where potential passengers can access. To understand the viability of such use cases, the vertiport owners …

Secure Lightweight Cryptographic Hardware Constructions For Deeply Embedded Systems, Jasmin Kaur

USF Tampa Graduate Theses and Dissertations

Lightweight cryptography plays a vital role in securing resource-constrained deeply-embedded systems such as implantable and wearable medical devices, smart fabrics, smart homes, radio frequency identification tags, sensor networks, and privacy-constrained usage models. The National Institute of Standards and Technology (NIST) initiated a standardization process for lightweight cryptography, a relatively-long multi-year effort, which eventually concluded in February 2023. Side-channel attacks (SCAs) exploit the vulnerabilities of a system by observing and analyzing side-channel information leakages. Fault analysis attacks are a type of active SCAs, where an intelligent adversary injects bit/byte faults into the implementation of a cryptographic cipher to recover the secret …

Enhancing Smart Grid Security And Reliability Through Graph Signal Processing And Energy Data Analytics, Md Abul Hasnat

USF Tampa Graduate Theses and Dissertations

Situational awareness in a large, dynamic, and complex cyber-physical critical infrastructure, such as a smart grid, is vital for ensuring its smooth and uninterrupted operation. With the evolving realities of the modern-day smart grids, new challenges associated with the situational awareness of these systems are emerging that demand intelligent and efficient solutions. This dissertation intends to address several problems for enhancing situational awareness by studying the dynamic interaction among the components of the smart grids through energy data analytics using various data-driven, machine learning, and graph signal processing (GSP) techniques. The presented work provides valuable insight into the data-driven analysis …

Adsorption Of Long And Short Per- And Polyfluoroalkyl Substances (Pfas) Onto Granular Activated Carbon And Porous Organic Polymers, Yan Zhang

USF Tampa Graduate Theses and Dissertations

Per- and polyfluoroalkyl substances (PFAS) are man-made environmental contaminants causing increasing global concern due to their adverse effect on environmental and human health. Conventional treatment methods are ineffective in removing short-chain PFAS because of their hydrophilicity and resistance to degradation. This study is to design an appropriate adsorption system to remove both long- and short-chain PFSA at environmentally relevant concentrations and conditions. Four primary research tasks were designed to evaluate the performance of a structurally-tunable and chemically-stable porous organic polymers (POPs) for PFAS removal under realistic environmental conditions, including the assessment of POPs’ performance without co-contaminants (Chapter 2), the assessment …

Exploratory Data-Driven Models For Water Quality: A Case Study For Tampa Bay Water, Sandra Sekyere

USF Tampa Graduate Theses and Dissertations

Water, a crucial resource for sustaining life, covers approximately 70% of the earth's surface. Nonetheless, the quality of water is deteriorating rapidly due to the rapid growth of urban areas and industries, which is a worrying trend causing harm to human health and the ecosystem. Water quality forecasting has a key role in water resources management by enabling effective pollution control, ecosystem monitoring, and decision-making.

Previously, traditional statistical models were used to forecast water quality, but they were unable to examine the non-linear relationships between water quality parameters, and they assumed that all datasets were distributed normally. This study uses …

Deep Learning Enhancement And Privacy-Preserving Deep Learning: A Data-Centric Approach, Hung S. Nguyen

USF Tampa Graduate Theses and Dissertations

Deep Learning and its applications have become attractive to a lot of research recentlybecause of its capability to capture important information from large amounts of data. While most of the work focuses on finding the best model parameters, improving machine learning performance from data perspective still needs more attention. In this work, we propose techniques to enhance the robustness of deep learning classification by tackling data issue. Specifically, our data processing proposals aim to alleviate the impacts of class-imbalanced data and non- IID data in deep learning classification and federated learning scenarios. In addition, data pre-processing strategies such that dimensionality …

Anaerobic Digestion Of Brewery Waste Including Spent Yeast And Hops, Dhanashree Rawalgaonkar

USF Tampa Graduate Theses and Dissertations

Florida is home to more than 300 craft breweries, that brew over a million barrels of beer annually. Brewing is an energy intensive process and produces large quantities of high strength waste including spent grains, yeast, hops, and high strength wastewater. Brewery wastewater, and spent yeast have high Chemical Oxygen Demand (COD) concentrations between 5000 mg/L – 10,000 mg/L, and 200,000 mg/L – 300,000 mg/L respectively. Brewery effluent wastewater is sent to Publicly Owned Treatment Works (POTWs) which implement high surcharges based on the strength of brewery effluent (COD concentration). While some of the spent yeast and hops can be …

Fabric-Based Organic Electrochemical Transistor Towards Wearable Ph Sensing Electronics, Nestor Osvaldo Marquez Rios

USF Tampa Graduate Theses and Dissertations

Wearable electronics interest has attracted the attention of a few sectors because of their applicability in different areas like healthcare, military, and our daily basis. Still building circuits on fabrics to make these wearable electronics is challenging. As transistors are the building blocks of electronic circuits and most of the biosensors, recently, fiber-shaped electrochemical transistors have been studied extensively for a lot of applications including bioelectronics. Fiber-based devices are getting popular in different applications due to their low fabrication cost, lightweight, and flexibility without losing their properties. Additionally, they are potentially suitable for making sensors on garments.

In this work, …

Resource Recovery From Crew Metabolic Wastes In Lunar And Martian Habitats: Reuse Of Effluent From An Anaerobic Membrane Bioreactor Treating Fecal Organic Matter As Fertilizer Source For Plants, Alexandra A. Smith

USF Tampa Graduate Theses and Dissertations

As humans set their sights on exploration of the Moon and Mars human focused challenges like providing potable water, supplying nutritious food to the astronaut crew, and managing their waste present themselves. There are no readily available resources on the Moon and Mars, therefore nothing should be considered unusable including the organic wastes (i.e., feces and urine) produced by the crew. Fecal matter is not currently recycled and is treated as solid waste. After collection, it is discarded out of the International Space Station where it is incinerated upon re-entry. This approach will not work on the Moon’s surface. There …

Characteristics And Hydraulic Behavior Of Adsorptive Media For Use In Permeable Reactive Barriers, Shelby Rocha

USF Tampa Graduate Theses and Dissertations

The Cargill ditch is located on the property of Se7en Wetlands, a 1600-ac treatment wetland system in Lakeland, Polk County, Florida. The Se7en Wetlands property was previously utilized for phosphate mining prior to the construction of the system. Nonpoint nutrient sources derived from remnants of abandoned phosphate mines – known as “legacy phosphorus” – become mobilized by stormwater runoff and impair surface water bodies by promoting harmful algal blooms (HABs). Thus, the Cargill ditch likely conveys nutrient rich flow resulting from legacy phosphorus and is thought to be one contributing factor in the occurrence of HABs within the treatment wetland …

Exploring Alternative Electron Donors For Heterotrophic Denitrification At A Water Reclamation Facility In Tampa Bay, Tejas Athavale

USF Tampa Graduate Theses and Dissertations

An excess of nitrogen in water can pose problems, ranging from algal blooms to creating toxic environments for marine life. Therefore, wastewater treatment plants need to remove nitrogen from wastewater during the treatment process. Biological nitrogen removal is one process these plants may use, which commonly involves nitrification and denitrification, converting nitrogen in the form of ammonia to nitrate, and then ultimately nitrogen gas. The process of denitrification often requires an electron donor, and methanol is a common choice. However, it is flammable, and therefore there is a need to explore alternative electron donors. Alternative donors can include manufactured chemicals …

Metachronal Locomotion: Swimming, Scaling, And Schooling, Kuvvat Garayev

USF Tampa Graduate Theses and Dissertations

This dissertation deals with one type of underwater locomotion called metachronal swimming in which the organism sequentially beats its multiple appendages allowing phase lag between adjacent neighbors. Metachronally swimming species are widespread and include copepods, shrimp, ctenophores, and tomopterid worms to name few. First, using the high-speed recording and planar particle image velocimetry (PIV) measurement, I report on kinematics of fast metachronal swimmer and constructive vortex interactions among its appendages and discuss its implications for improved performance regarding the swimming. Second, I show how hydrodynamic performance of all metachronal swimmers (paramecia, copepods, tomopterid worms, krill etc.) can be scaled by …

Insect Classification And Explainability From Image Data Via Deep Learning Techniques, Tanvir Hossain Bhuiyan

USF Tampa Graduate Theses and Dissertations

Since the dawn of the Industrial Revolution, humanity has always tried to make labor more efficient and automated, and this trend is only continuing in the modern digital age. With the advent of artificial intelligence (AI) techniques in the latter part of the 20th century, the speed and scale with which AI has been leveraged to automate tasks defy human imagination. Many people deeply entrenched in the technology field are genuinely intrigued and concerned about how AI may change many of the ways in which humans have been living for millennia. Only time will provide the answers. This dissertation is …

On The Performance Enhancement Of Beamspace Mimo And Non-Orthogonal Multiple Access For Future Cellular Networks, Sinasi Cetinkaya

USF Tampa Graduate Theses and Dissertations

The ever-growing demand for higher data rates and greater data capacity at lower cost has led the mobile cellular industry to investigate new physical layer techniques and possible utilization of unused spectrums at higher frequencies for next-generation cellular networks. Thus, exploitation of the millimeter-wave (mmWave) spectrum and non-orthogonal multiple-access (NOMA) have been envisioned as the most promising enablers in meeting capacity demand. Due to the smaller wavelengths offered in mmWave frequencies, it is possible to deploy many antennas into a relatively smaller physical space in mmWave frequencies. This property leads to a promising integration between mmWave and massive multiple-input multiple-output …