Physical Sciences and Mathematics Commons^™

Securing Critical Cyber Infrastructures And Functionalities Via Machine Learning Empowered Strategies, Tao Hou

USF Tampa Graduate Theses and Dissertations

Machine learning plays a vital role in understanding threats, vulnerabilities, and security policies. In this dissertation, two machine learning empowered approaches on improving the security of critical cyber infrastructures and functionalities will be discussed.

The first work focuses on preventing attacks that use adversarial, active end-to-end topology inference to obtain the topology information of a target network. The topology of a network is fundamental for building network infrastructure functionalities. In many scenarios, enterprise networks may have no desire to disclose their topology information. To this end, we propose a Proactive Topology Obfuscation (ProTO) system that adopts a detect-then-obfuscate framework: (i) …

Video Anomaly Detection: Practical Challenges For Learning Algorithms, Keval Doshi

USF Tampa Graduate Theses and Dissertations

Anomaly detection in surveillance videos is attracting an increasing amount of attention. Despite the competitive performance of several existing methods, they lack theoretical performance analysis, particularly due to the complex deep neural network architectures used in decision making. Additionally, real-time decision making is an important but mostly neglected factor in this domain. Much of the existing methods that claim to be online, depend on batch or offline processing in practice. Furthermore, several critical tasks such as continual learning, model interpretability and cross-domain adaptability are completely neglected in existing works. Motivated by these research gaps, in this dissertation we discuss our …

Metabolomic Analysis, Identification And Antimicrobial Assay Of Two Mangrove Endophytes, Stephen Thompson

USF Tampa Graduate Theses and Dissertations

Natural products have played major roles in drug discovery and provided sources for many new drugs. Secondary metabolites, also called natural products, are organic compounds that are produced from fungi, bacteria, and other living organisms. Secondary metabolites produced by endophytic fungi include alkaloids, phenols, peptides, enzymes, polyketides, and terpenes. Endophytic fungi are rich sources of secondary metabolites and demonstrate bioactivity against many human pathogens including the ESKAPE pathogens. This thesis explores the diverse roles of endophytic fungi and their production of unique secondary metabolites for potential drug discovery and development. Secondary metabolites from two endophytic fungi (EG10-21E-2-HDAC & TAP14-34A-2-HDAC), collected …

Synthesis And Antibacterial Testing Of Novel Thiosulfonate Compounds, Lindsay I. Blume

USF Tampa Graduate Theses and Dissertations

Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Staphylococcus aureus (VRSA) are increasing concerns in the medical community. In addition to the threat of Staphylococcus aureus, the increase in number and severity of infections caused by other antibiotic-resistant bacteria is problematic to human health, particularly among the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter). The antibiotics like the penicillins and cephalosporins used commonly to treat MRSA, VRSA, and ESKAPE pathogens have continued to decline in the effectiveness. Our laboratory has developed a number of new families of anti-MRSA and anti-VRSA antibacterial compounds. In this thesis, …

Integration Of Sustainability Into Higher Education Policies: A Case Study Of The University Of South Florida, Mehmet Z. Apaydin

USF Tampa Graduate Theses and Dissertations

Sustainability and the United Nations Sustainable Development Goals (SDGs) are not new notions for higher education institutions (HEIs). However, well-organized efforts to make campuses "sustainable" are not common, and the efforts are modest compared to the institutional capabilities. This thesis, a case study of the University of South Florida (USF), was designed to explore how sustainability values and SDGs are incorporated into higher education policies. To accomplish this, the study employed a mixed method design that includes a literature review, an overview of policies and implementations, document content analysis, a program and course inventory, a keyword analysis, and semi-structured interviews. …

Determinations Of Chemical Equilibria In Natural Waters Using Spectrophotometric Techniques, Katelyn M. Schockman

USF Tampa Graduate Theses and Dissertations

Accurate characterizations of chemical equilibria and thermodynamic processes in natural waters are key components for assessing the current state of our global climate and predicting future changes, especially for observations of small rates of change over long time scales. One of the most important chemical systems in natural waters is the system of inorganic carbon species comprised of carbon dioxide (CO2), bicarbonate, and carbonate. The bicarbonate dissociation constant, K2, describes the relationship between pH and the relative concentrations of bicarbonate and carbonate ions at thermodynamic equilibrium. The carbonate/bicarbonate equilibrium quotient is required in nearly all CO2 system calculations relevant to …

Data-Driven Design And Analysis Of Next Generation Mobile Networks For Anomaly Detection And Signal Classification With Fast, Robust And Light Machine Learning, Muhammed Furkan Küçük

USF Tampa Graduate Theses and Dissertations

This research focuses on machine (and deep) learning applications (including clustering,anomaly detection and signal classification) for self-organizing and next generation mobile networks in wireless communications. Specifically, this dissertation document will address the three different topics.

First, in the study titled “Performance analysis of neural network topologies and hyperparameters for deep clustering”, we explore the relationship between the clustering performance and network complexity. Deep learning found its initial footing in supervised applications such as image and voice recognition successes of which were followed by deep generative models across similar domains. In recent years, researchers have proposed creative learning representations to utilize …

Stability Analysis Of Delay-Driven Coupled Cantilevers Using The Lambert W-Function, Daniel Siebel-Cortopassi

USF Tampa Graduate Theses and Dissertations

A coupled delay-feedback system of two cantilevers can yield greater sensitivity than that of asingle cantilever system, with potential applications in atomic force microscopy. The Lambert W-function analysis concept for delay differential equations is used to more accurately model the behavior of specific configurations of these cantilever systems. We also use this analysis concept to find parameters which yield stability for greater parameter ranges, of the delay differential equations. The Q factor, or quality factor, is the ratio of energy stored in the system, to the energy lost per fixed oscillation/movement cycle. Having stability of the cantilevers corresponds to the …

A Functional Optimization Approach To Stochastic Process Sampling, Ryan Matthew Thurman

USF Tampa Graduate Theses and Dissertations

The goal of the current research project is the formulation of a method for the estimation and modeling of additive stochastic processes with both linear- and cycle-type trend components as well as a relatively robust noise component in the form of Levy processes. Most of the research in stochastic processes tends to focus on cases where the process is stationary, a condition that cannot be assumed for the model above due to the presence of the cyclical sub-component in the overall additive process. As such, we outline a number of relevant theoretical and applied topics, such as stochastic processes and …

Isotopic Study Of The Waters From The Sulphur Springs Catchment, Tampa, Florida, Esra Zengin

USF Tampa Graduate Theses and Dissertations

A stable isotope study was carried out using precipitation, spring water, groundwater well sample, and a seawater sample during the wet season in the Sulphur Springs watershed in Tampa, Florida. Studies that track long term isotopic variation over wet seasons are limited in the region. To fill this knowledge gap, this study aims to quantify the contributions of precipitation and diffuse sources to discharge in Sulphur Springs. A three-component mixing model was applied using δ18O and δ2H values to determine different source water contributions to spring water discharge. The three-component mixing model calculations suggest spring water consists mainly of diffuse …

An Investigation Into The Protein Dynamics And Proton Transfer Mechanism Of Class-A Β-Lactamase (Ctx-Ms) By Nmr Spectroscopy, Radwan Ebna Noor

USF Tampa Graduate Theses and Dissertations

Extended-spectrum β-lactamases (ESBLs) of different Enterobacteriaceae (e.g. Escherichia coli, Klebsiella pneumoniae) have developed significant resistance mechanisms against antibiotics. ESBLs, like class A CTX-Ms (cefotaximases) enzymes hydrolyze the β-lactam ring of different antibiotics such as penicillins and third-generation oxyimino-cephalosporins. Although CTX-Ms are repeatedly found in many clinical and community settings, molecular-level information on their function/activity is currently limited to structural studies performed by X-ray crystallography. In order to gain further insights into the structure and functions of this class of proteins, it is also essential to fully understand their dynamic and chemical properties in solution. In order to better understand the …

Measuring Sustainable Development Through Tax Increment Financed Brownfield Redevelopment Statutes: A Florida Case Study, Jeff Burton

USF Tampa Graduate Theses and Dissertations

This research measures the theoretically sustainable development synergy of United States’ redevelopment, tax increment, and brownfield statutes and questions local redevelopment professionals on this combination’s implementation. This policy’s integration and application measurements guide increased knowledge and best practice methods in the path of America’s population migration into urbanized areas, thus managing the economic, environmental, and social impacts for future generations.

This examination used a pragmatic, qualitative, and quantitative mixed-method approach to identify, collect, code, and analyze redevelopment, tax increment, and state brownfields laws. An exhaustive literature review of the laws’ histories explained when and why they exist. In addition, a …

Desertification Risk Analysis For Wildlife In The Desert Renewable Energy Conversation Plan Area Of California, Serdar Sagdic

USF Tampa Graduate Theses and Dissertations

Desertification is one of the primary threats facing the sustainability of the Earths’s natural resources. Desertification it is an outcome of human impacts to ecosystems and alterations of climate patterns resulting in land degradation and adverse effect on natural resources, vegetation loss, soil infertility, and water scarcity. These changes influence the existence and distribution of wildlife by reducing the availability and quality of habitat that provides food, water, cover, and other life requisites. Therefore, this study aimed at evaluation of potential desertification risks on wildlife species in the Desert Renewable Energy and Conservation Plan (DRECP) area of California.

The DRECP …

Bioactivity Of Suberitenones A And B, Jared G. Waters

USF Tampa Graduate Theses and Dissertations

Throughout human history, natural products have formed the foundation of medicine. In ancient times, a myriad of herbs and fungi have been attributed properties of healing and rejuvenation. Today, that foundation still very much exists, as natural product chemists isolate bioactive compounds from plants, fungi, animals, and microorganisms alike. As more of these secondary metabolites are discovered, scientists pursue more and more sources of biodiversity that may yield new and unprecedented compounds. To this end, Antarctica has become of particular note, as its unique environmental conditions and highly isolated nature make for rare and unusual adaptations in its native wildlife. …

Computing Group-By And Aggregate In Massively Parallel Systems, Chengcheng Mou

USF Tampa Graduate Theses and Dissertations

The semiconductor industry has mainly exploited two routes for designing microprocessors. The multi-core route aims to speed up the performance of latency-oriented processing. In contrast, the many-thread route concentrates on throughput-oriented improvement of parallel processing. Many-thread microprocessors, such as Graphics Processing Units (GPUs), are leading the computing capability for this past a decade. According to the current hardware market, at the similar price range, the ratio of peak computing power between multi-core CPUs and many-thread GPUs is up to 15X. This large performance gap on data processing has motivated many practitioners in database community to exploit computation-intensive parts on GPU …

Block Copolymer Directed Self-Assembly: Exploring The Efficacy Of Applications In Semiconductor Fabrication, Jakin Bryce Delony

USF Tampa Graduate Theses and Dissertations

Over the course of the past 80 years, semiconductor devices have become increasingly ubiquitous in everyday life.From constructing mainframes that encompassed entire rooms during the 1940s, to inventing personal computers in the 1980s, to developing progressively faster smartphones and wearable technology in the 2010s, the primary driving force behind the Digital Revolution has been increasing transistor counts, and thus computing power, via incremental improvements in optical lithography. In 1965, Intel co-founder Gordon Moore boldly predicted that the transistor density of semiconductor devices would double approximately every 18-24 months. While this prediction -- now colloquially referred to as Moore's Law -- …

Empirical And Modeled Δ13c And Δ15n Isoscapes In The Gulf Of Mexico And Their Application To Fish Eye Lens Migration Studies, Brianna Michaud

USF Tampa Graduate Theses and Dissertations

Isoscapes are depictions of the spatial patterns of isotopic values in a given area. Isoscapes can be created using measurements form samples (empirical isoscapes) or using statistical models of spatial isotopic variation (modeled isoscapes). Isoscapes have a wide variety of potential applications though, in the realm of marine ecology, they are most often used infer ecological processes, food web linkages, the origin of samples, and the movements of marine organisms.

However, to use isoscapes for these applications, it is necessary to have isoscapes at spatial scales relevant to the application in question. It is also necessary to have isoscapes that …

Relationships Among The Community Of Inquiry, Achievement Emotions, And Academic Achievement In Asynchronous Online Learning In Higher Education, David H. Tai

USF Tampa Graduate Theses and Dissertations

This research aimed to investigate how achievement emotions predict, mediate, and affect academic achievement in online learning. Online learning has been proliferating, but little is known about how emotion mediates cognition in the Community of Inquiry framework. Recent progress in cognitive neuroscience provided the theoretical foundation for researchers to investigate emotion's role in online learning, especially academic achievement. The researcher of this study adopted a quantitative non-experimental research design to investigate how achievement emotions mediated, predicted, and affected academic achievement in the Community of Inquiry framework. The Partial Least Square Structure Equation Modeling (PLS- SEM) method was adopted for statistical …

Advances And Applications Of Optimal Polynomial Approximants, Raymond Centner

USF Tampa Graduate Theses and Dissertations

The history of optimal polynomial approximants (OPAs) dates back to the engineering literature of the 1970s. Here, these polynomials were studied in the context of the Hardy space H^2(X), where X denotes the open unit disk D or the bidisk D^2. Under certain conditions, it was thought that these polynomials had all of their zeros outside the closure of X. Hence, it was suggested that these polynomials could be used to design a stable digital filter. In recent mathematics literature, OPAs have been studied in many different function spaces. In these settings, numerous papers have been devoted to studying the …

Soft Magnetic Composite Substrates For Rf/Microwave Applications, Poonam Lathiya

USF Tampa Graduate Theses and Dissertations

Novel soft magnetic ferrite materials will play a crucial role in next-generation over one trillion sensors (also known as “trillion sensor economy) related to 5G communications and internet of things, as these materials can achieve improved wireless power and signal transfer efficiency with high operation frequency. In this work, Ni-Cu-Zn and Ni-Co-Zn ferrites with high permeability, high permittivity, and low magnetic and dielectric losses were prepared for RF and microwave device applications. Frequency dispersion of RF complex permeability of Ni-Cu-Zn ferrites prepared under different applied hydraulic pressures and durations have been thoroughly investigated. The Ni0.35Cu0.19Zn0.46Fe2O4 ferrites were prepared by conventional …

Finding Signal In The Noise: High-Fidelity, Quantitative, Optical Blood Perfusion Imaging With Interference, Abdul Mohaimen Safi

USF Tampa Graduate Theses and Dissertations

For label-free, non-invasive, wide field-of-view (FOV) imaging/monitoring of blood flow, speckle-based approaches are gaining popularity. However, to obtain quantitative flow information, speckle techniques rely on the multi-exposure scheme which requires complex, bulky, and expensive instrumentation, limiting its application to preclinical studies. This dissertation directly addresses these issues. In the first part of this dissertation, we report a novel single shot synthetic multi-exposure speckle imaging (syMESI) method to synthetically produce multi-exposure images from one short single exposure speckle image using spatial binning/averaging. We demonstrate that syMESI can reimagine conventional hardware based MESI, with low-cost single exposure laser speckle imaging (LSCI) instrumentation. …

Light-Controlled Magnetism And Magnetic Sensing In Two-Dimensional Vanadium Dichalcogenides And Related Semiconductors, Valery Ortiz Jimenez

USF Tampa Graduate Theses and Dissertations

Atomically thin transition metal dichalcogenide (TMD) semiconductors hold enormous potential for modern optoelectronic devices, magnetic sensing, and quantum computing applications. By inducing long-range ferromagnetism (FM) in these semiconductors by stacking them with other magnetic TMDs or through the introduction of small amounts of a magnetic dopant, it is possible to extend their potential in emerging spintronic applications. In this dissertation, we aim to demonstrate two important applications of these materials: magnetic sensing and light-mediated, room temperature (RT) FM in V-doped WS2 (V-WS2) and V-WSe2 monolayers and in ML VSe2/TS2 (T = Mo and W) heterostructures. In this work, we developed …

On The Reliability Of Wearable Sensors For Assessing Movement Disorder-Related Gait Quality And Imbalance: A Case Study Of Multiple Sclerosis, Steven Díaz Hernández

USF Tampa Graduate Theses and Dissertations

Approximately 33 million American adults had a movement disorder associated with medication use, ear infections, injury, or neurological disorders in 2008, with over 18 million people affected by neurological disorders worldwide. Physical therapists assist people with movement disorders by providing interventions to reduce pain, improve mobility, avoid surgeries, and prevent falls and secondary complications of neurodegenerative disorders. Current gait assessments used by physical therapists, such as the Multiple Sclerosis Walking Scale, provide only semi-quantitative data, and cannot assess walking quality in detail or describe how one’s walking quality changes over time. As a result, quantitative systems have grownas useful tools …

Improving Robustness Of Deep Learning Models And Privacy-Preserving Image Denoising, Hadi Zanddizari

USF Tampa Graduate Theses and Dissertations

Applications of deep learning models and convolutional neural networks have been rapidly increased. Although state-of-the-art CNNs provide high accuracy in many applications, recent investigations show that such networks are highly vulnerable to adversarial attacks. The black-box adversarial attack is one type of attack that the attacker does not have any knowledge about the model or the training dataset, but it has some input data set and theirlabels.

In this chapter, we propose a novel approach to generate a black-box attack in a sparse domain, whereas the most critical information of an image can be observed. Our investigation shows that large …

Application Of The Riemann-Hilbert Method To Soliton Solutions Of A Nonlocal Reverse-Spacetime Sasa-Satsuma Equation And A Higher-Order Reverse-Time Nls-Type Equation, Ahmed Ahmed

USF Tampa Graduate Theses and Dissertations

For many years, the study of integrable systems has been one of the most fascinating branches of mathematics and has been thought to be an interesting area for both mathematicians and physicists alike.Many natural phenomena can be predicted by using integrable systems, particularly by studying their different solutions, as well as analyzing and exploring their properties and structures. They are commonly found in nonlinear optics, plasmas, ocean and water waves, gravitational fields, and fluid dynamics. Typical examples of integrable systems include the Korteweg-de Vries (KdV) equation, the nonlinear Schrödinger (NLS) equation, and the Kadomtsev-Petviashvili (KP) equation. Solitons are intrinsic solutions …

Development Of Enhanced Algae Strains And Sustainable Cultivation Processes For Production Of Algal Lipids For Biofuels And Bioproducts, Enlin Lo

USF Tampa Graduate Theses and Dissertations

The establishment of an algae industry is crucial for addressing global biofuel and bioproduct demand that meets the Sustainable Development Goals (SDG) worldwide. Photosynthetic microalgae are excellent sources for food, fiber, fuel, feed, and fertilizer, which are the 5Fs of the SDG. However, at present, algae-based materials are not cost-competitive or sufficiently sustainable. Improved productivity, lower cultivation cost, and reduced use of resources are required to transition from lab to industry, necessitating the development of superior strains that have high productivity and can tolerate environmental stress, such as temperature and salinity, so they can be cultivated at large scale outdoors …

Exploring The Structure And Activity Of Metallo-Tetracyclines, Shahedul Islam

USF Tampa Graduate Theses and Dissertations

Copper as a key component of electron transport chain of eukaryotes is an essential transition metal ion. Copper homeostasis in mammals complex and tightly regulated. Its strong reactivity together with binding with biologically important chemicals can have important repercussions in human health and overall environment. Tetracycline as one of most abundantly used antibiotic of the world has become abundant in the environment as well. Herein in this dissertation we take the journey to explore the complexation of tetracycline with metals in the environment and the intricate interaction between copper and tetracycline by investigating their oxidative behavior once they are complexed. …

Adversarial And Data Poisoning Attacks Against Deep Learning, Jing Lin

USF Tampa Graduate Theses and Dissertations

Machine translation software, image captioning, grammar check (Grammarly), chatbot, real-time captioning and translation, music genre classification, and document classification are a few examples of deep learning applications that achieve outstanding performance in areas where traditional statistical techniques have difficulty performing classification and/or regression. Google translator has over 100 billion daily users and can translate 109 languages instantly (much faster than a human translator). AlphaGo won Lee Sedol, the eighteen-time world champion. Microsoft Team's living captioning provides accurate real-time captioning as a speaker speaks. Deep learning achieves undoubtedly remarkable performance. However, recent studies on adversarial attacks and data poisoning attacks show …

Geothermal Development In Kenya: Gender Based Socio-Cultural And Socio-Economic Implications, Faye N. Ricker

USF Tampa Graduate Theses and Dissertations

This dissertation is an ethnographic case study that analyzes the gendered socio-cultural and socio-economic implications for a community that was displaced in order to develop a geothermal energy system in Kenya. The implications are rendered particularly interesting because the displaced community is also one of the communities served by the geothermal power grid. The analysis employs a composite framework of Feminist Political Ecology and the Political Ecology of Climate Change Mitigation. This work explores gendered perceptions and control of energy, livelihood activities, place attachment, and the cultural/spiritual significance of geothermal energy.

Geothermal energy is a potentially promising source of low-carbon …

First-Principles-Based Modeling Of Energy Converting Properties Of Conventional And Emerging Ferroelectrics, Maggie Kingsland

USF Tampa Graduate Theses and Dissertations

Ferroelectric materials are a type of multifunctional material that exhibit spontaneous polarization reversable by the application of an electric field. They are used in many technologies such as ferroelectric RAM (FeRAM), piezoelectric devices, RFID chips, and capacitors. However, the most commonly used ferroelectrics are often made with rare, expensive elements and are not environmentally friendly. For example, many prototypical ferroelectrics contain elements such as lead, zirconium, and titanium. As technology grows more advanced, there is a need to discover or manufacture cheaper ferroelectrics and to make them less impactful on human health and the earth as a whole. We set …