Physical Sciences and Mathematics Commons^™

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 …

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 …

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 …

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. …

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 …

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 …

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 …

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. …

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 …

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 …

Study On New Reactivity Of Vinyl Gold And Its Sequential Transformations, Teng Yuan

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) the study of new reactivity of vinyl gold(I) and synergistic gold-iron catalyzed regioselective crossed aldol reaction. 2) synergistic gold-iron catalyzed amide crossed aldol reaction by using ynamides as ‘masked’ amides. 3) alkyne trifunctionalization via divergent gold catalysis: combining three modes of gold catalysis: π activation, nucleophilic addition of vinyl gold and gold redox catalysis. This novel method affords access to constructing C-N, C-O and C-C bond in one step at mild condition.

In the first part, a new reaction mode in gold catalysis will be introduced. Due to the protodeauration of vinyl gold …

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 …

A Statistical Method For Quantifying Animal Interaction; Combining Time Geography And Simulation, Zachary J. Smith

USF Tampa Graduate Theses and Dissertations

Dynamic interaction (DI) describes the synchronous interaction of one or more individual animals over time. Current methods to quantify DI from tracking data are lacking. They typically require synchronized tracking data which limits their applicability to most studies. They also often do not have built-in tests of significance to evaluate interaction, and if so, rely on random walk models that lack biological realism. This research aimed to develop and evaluate a new way of measuring animal interaction that overcomes these limitations. The goal was to create a statistical method for quantifying and evaluating interaction that is relevant across computational, behavioural, …

Fiber-Based Electrical Energy Storage And Harvesting Devices For Wearable Electronics, Tareq Kareri

USF Tampa Graduate Theses and Dissertations

Over the past few years, smart textiles and wearable technologies have received tremendous attention due to their functionalities and characteristics, which could be used in a variety of ways in healthcare, sports/leisure, fashion, military, personal protective, and energy applications. These technologies depend on self-power systems, which require energy sources (e.g., batteries, supercapacitors, and solar cells) to power their projected functionalities in the future. Therefore, fabricating energy harvesting cells (i.e., solar cells) and energy storage cells (i.e., batteries and supercapacitors) in the form of fibers are promising solutions for powering wearable electronics due to their unique features such as flexibility and …

Measuring And Improving Student Attitude In College-Level Chemistry: A Novel Survey Methodology And Social-Psychological Interventions, Ying Wang

USF Tampa Graduate Theses and Dissertations

Students’ attitude has been an important focus in the chemistry education community. However, there is a lack of research in evaluating interventions aiming to improve students’ attitude. Social-psychological interventions (SPIs), brief interventions that target students’ subjective experiences, were demonstrated to improve students’ attitude in instructional settings. In addition, accurately measuring students’ attitude helps researchers better understand the impact of the intervention. Therefore, the major goal of this work is to explore practices, particularly a novel survey methodology and a social-psychological intervention (SPI), to facilitate measuring and improving students’ attitude in college-level chemistry courses. This work also paid particular attention to …

Exploring Magneto-Excitons In Bulk And Mono-Layer Semiconductors Using Non-Linear Spectroscopy Techniques, Varun Mapara

USF Tampa Graduate Theses and Dissertations

The research in two-dimensional (2D) materials has evolved from ``traditional" quantum wells based on group III-V and II-VI semiconductors to atomically thin sheets of van der Waals materials such as 2D semiconducting Transition Metal Dichalcogenides (TMDs). These 2D materials remain a stimulating field that continues to introduce new challenges. From both a fundamental physics and technological perspective, magneto-optical spectroscopy has been an essential tool in this research field. TMDs, for example, pose the challenge of characterizing their spin-valley-resolved physics and deriving implications in quantum computation and information research. With the discovery of valley Zeeman effects, the spin-valley physics of TMDs …

A Physically Constrained Wavelet-Aided Statistical Model (Pcwasm) For Multidecadal Groundwater Dynamics Predictions And Climate Change Evaluation, Fatih Gordu

USF Tampa Graduate Theses and Dissertations

Long-term groundwater management relies on forecasts of decadal or longer groundwater levels driven by nested scales of variability in climate. Discerning the impacts of anthropogenic stressors on groundwater is also critical for establishing predevelopment benchmark groundwater conditions and developing climate change adaptation strategies to reduce risks and increase resiliency. This research demonstrates the development and successful applications of a new methodology to predict and assess multidecadal groundwater dynamics for understanding long-term effects of climate change and groundwater withdrawals.

A Physically Constrained Wavelet-Aided Statistical Model (PCWASM) is first introduced to analyze and predict monthly aquifer levels on multidecadal time scales. The …

An Internet Of Medical Things (Iomt) Approach For Remote Assessment Of Head And Neck Cancer Patients, Ruchitha Chinthala

USF Tampa Graduate Theses and Dissertations

Internet-of-Medical-Things (IoMT) allows for a smart healthcare system to remotely monitor and assess patient’s progress at home. Head and neck cancers (HNC) are treated with various treatment options which are associated with significant side effects, mainly shoulder dysfunction, and trismus (spasm of jaw muscles). However, measurement of patient’s progress, and side effects while undergoing treatment, is limited to evaluation received based on scheduled appointments. Development of strategies to enhance monitoring during follow-up period is needed for earlier identification of problems such as trismus and shoulder dysfunction. In this interdisciplinary research, for the first time, we develop an IoMT enabling application, …

Characterizing Explosive Volcanic Eruptions Using Tephra Fall Deposit Data, Robert Constantinescu

USF Tampa Graduate Theses and Dissertations

This dissertation addresses the estimation of the magnitudes and intensities of explosive volcanic eruptions using tephra fall deposits and numerical modeling. Tephra fall deposits retain information about eruption dynamics. Volcanologists sample tephra fall deposits and measure the thickness, extent and grain size distribution to estimate the erupted volume and plume height of explosive eruptions. These terms are known as eruption source parameters. These parameters are used to classify the intensity and magnitude of the eruption on a scale such as the Volcanic Explosivity Index (VEI). Accurate estimation of the intensity and magnitude of explosive eruptions is a crucial factor in …

Watershed Management For Nutrient Control In Taylor Creek And Nubbins Slough, Florida, Rachael Z. Cooper

USF Tampa Graduate Theses and Dissertations

Despite efforts to improve water quality within the watershed since the 1970s, harmful algal blooms (HABs) still occur within Lake Okeechobee (LO). HABs are harmful to the people, the ecosystem, and the economy dependent on the lake. Taylor Creek Nubbins Slough (TCNS) is a subwatershed of the lake, contributing to a large percentage of the nutrient loading. Due to the size and complexity of LO’s watershed, two smaller basins within the TCNS subwatershed were selected to evaluate the following research questions: (1) How do water quality trends contrast between two basins? (2) How do nutrient load and treatment within the …

Analyzing Decision-Making In Robot Soccer For Attacking Behaviors, Justin Rodney

USF Tampa Graduate Theses and Dissertations

In robotics soccer, decision-making is critical to the performance of a team’s SoftwareSystem. The University of South Florida’s (USF) RoboBulls team implements behavior for the robots by using traditional methods such as analytical geometry to path plan and determine whether an action should be taken. In recent works, Machine Learning (ML) and Reinforcement Learning (RL) techniques have been used to calculate the probability of success for a pass or goal, and even train models for performing low-level skills such as traveling towards a ball and shooting it towards the goal[1, 2]. Open-source frameworks have been created for training Reinforcement Learning …

Predicting The Number Of Objects In A Robotic Grasp, Utkarsh Tamrakar

USF Tampa Graduate Theses and Dissertations

Picking up the desired number of objects at once from a pile is still very difficult to dofor a robot. The main challenge is predicting the number of objects in the grasp. This thesis describes several deep-learning-based prediction models that predict the number of objects in the grasp of a Barrett hand using the tactile sensors on its fingers and palm and its joint angles and torque (strain gauge) readings. The deep learning models include various architectures using autoencoders and vision transformers. We evaluated the models with a dataset of grasping 0, 1, 2, 3, and 4 spheres. Then, we …

Using Fine-Scale Aquatic Habitat Data To Construct Dreissenid Sdms In The Laurentian Great Lakes, Grace C. Henderson

USF Tampa Graduate Theses and Dissertations

The invasion of the Laurentian Great Lakes by aquatic invasive species (AIS) has been the subject of investigation for decades, due to their dramatic alterations to the ecosystem and high economic costs. Two AIS with the largest impacts are dreissenid zebra and quagga mussels, and though these species have been studied extensively, questions remain about what factors control their distributions, and whether lake warming will alter these distributions. Species distribution models (SDMs) offer a powerful tool to examine the relationship between species presences and environmental variables, which are typically bioclimactic data. The creation of the Aquatic Habitat (AqHab) dataset containing …

Developing Efficient Transition Metal Catalyzed C-C & C-X Bond Construction, Chiyu Wei

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The synergistic Pd/enamine catalysis for asymmetric hydrocarbon functionalization of unactivated alkenes with ketones; 2) Gold redox catalysis with a selenium cation as mild oxidant; 3) HFIP promoted disulfidation and diselenation of alkyne, alkene, and allene.

Palladium-catalyzed alkene activation has its intrinsic limitation: 1) the requirement of a pre-functionalized alkene to form a Pd π-allyl complex; 2) problematic reversible β-H elimination. It always leads to limited reaction scope and losing of the stereochemical control. Synergistic palladium and enamine catalysis was conducted to promote ketone addition to unactivated olefins. A secondary amine-based organocatalyst was identified …

Measurements Of Generalizability And Adjustment For Bias In Clinical Trials, Yuanyuan Lu

USF Tampa Graduate Theses and Dissertations

While randomized controlled trials (RCTs) are widely used as a gold standard in clinical research and public health, they are criticized because of a potential lack of generalizability, as the trial patients may be unrepresentative of the target patient population. Few research addresses how to assess and evaluate the generalizability of RCTs. As we know, patients are rarely selected on a random basis from a well-defined patient population of interest into a clinical trial. Generalizing findings from the RCT samples to the patient population has begun to receive increasing attention. We simulate a patient population with treatment effect size of …

Effective Statistical And Machine Learning Methods To Analyze Children's Vocabulary Learning, Houston T. Sanders

USF Tampa Graduate Theses and Dissertations

Poor methodological and statistical practices can lead to unreliable results. The collaboration between statisticians and researchers can remedy this. Early education intervention research rarely uses advanced statistical techniques. Within early education, vocabulary instruction has been well-studied, yet outcomes continue to be underwhelming. The specialized knowledge and expertise statisticians possess has the potential to enhance word learning research by applying sophisticated analyses not commonly used. Choosing vocabulary words for instruction can be a daunting task and is highly subjective. In an effort to aid in the selection process, researchers use a word selection framework that groups words into three tiers. Even …

Evaluation Of Hydrodynamic Effects Of Waterway Restoration On An Estuarine Ecosystem, Megan Kramer

USF Tampa Graduate Theses and Dissertations

Estuaries are hydrodynamically complex for they are influenced by tidal forces, freshwater flows, salinity variations, and often intricate coastal land morphology. Furthermore, many estuaries are subject to constant anthropogenic stresses due to dense coastal populations, which are expected to be exacerbated by changing climate trends. The 1,800 home residential Manchester Waterway (MW) community located in Charlotte Harbor (along the Gulf of Mexico in Southwest Florida), is interested in improving boat access by restoring a previous connection between the local waterway and the harbor, separated by a barrier peninsula. The proposed connections aim to reduce boat traffic and travel time through …

Assessing Changes In Actual Air Quality And Public Perceptions Of Air Quality In Kathmandu Valley Nepal Pre And Post Covid-19 Lockdown, Robin Margherita Rives

USF Tampa Graduate Theses and Dissertations

Air pollution is a global concern. Cities around the world fail to meet air quality standards set by the World Health Organization Air Quality Guidelines, which has a significant impact on public health. As the capital city and largest metropolitan region of Nepal, Kathmandu is a hotspot for urban pollution in South Asia. Nepal faces emissions from both internal and external sources. External sources include emissions from Nepal’s neighboring countries of India and China and emissions resulting from tourism. Internal sources of pollution in the country include brick and cement factories, consumption of energy from traditional sources such as biomass, …