Physical Sciences and Mathematics Commons^™

Graph-Based Latent Embedding, Annotation And Representation Learning In Neural Networks For Semi-Supervised And Unsupervised Settings, Ismail Ozsel Kilinc

USF Tampa Graduate Theses and Dissertations

Machine learning has been immensely successful in supervised learning with outstanding examples in major industrial applications such as voice and image recognition. Following these developments, the most recent research has now begun to focus primarily on algorithms which can exploit very large sets of unlabeled examples to reduce the amount of manually labeled data required for existing models to perform well. In this dissertation, we propose graph-based latent embedding/annotation/representation learning techniques in neural networks tailored for semi-supervised and unsupervised learning problems. Specifically, we propose a novel regularization technique called Graph-based Activity Regularization (GAR) and a novel output layer modification called …

Investigation Of Sediment Ridges Using Bathymetry And Backscatter Near Clearwater, Florida, Lewis Stewart

USF Tampa Graduate Theses and Dissertations

Changes in sediment morphology on the West Florida Shelf is investigated over a 14-year time period using multibeam bathymetry and backscatter in water depths between 10 m and 20 m, off the coast of Indian Rocks Beach, Pinellas County, Florida. Bathymetric surveys collected in 2002 (Kongsberg EM 3000 at 300 kHz) and 2016 (Reson 7125 at 400 kHz) were processed using CARIS Hips and Sips to create bathymetric maps and backscatter images. These data were then interpreted and compared in order to test hypotheses and answer questions related to sediment migration and sediment volume change.

The following questions prompted this …

Context-Based Human Activity Recognition Using Multimodal Wearable Sensors, Pratool Bharti

USF Tampa Graduate Theses and Dissertations

In the past decade, Human Activity Recognition (HAR) has been an important part of the regular day to day life of many people. Activity recognition has wide applications in the field of health care, remote monitoring of elders, sports, biometric authentication, e-commerce and more. Each HAR application needs a unique approach to provide solutions driven by the context of the problem. In this dissertation, we are primarily discussing two application of HAR in different contexts. First, we design a novel approach for in-home, fine-grained activity recognition using multimodal wearable sensors on multiple body positions, along with very small Bluetooth beacons …

Design And Simulation Of A Miniature Cylindrical Mirror Auger Electron Energy Analyzer With Secondary Electron Noise Suppression, Jay A. Bieber

USF Tampa Graduate Theses and Dissertations

In the nanoscale metrology industry, there is a need for low-cost instruments, which have the ability to probe the structrure and elemental composition of thin films. This dissertation, describes the research performed to design and simulate a miniature Cylindrical Mirror Analyzer, (CMA), and Auger Electron Spectrometer, (AES). The CMA includes an integrated coaxial thermionic electron source. Electron optics simulations were performed using the Finite Element Method, (FEM), software COMSOL. To address the large Secondary Electron, (SE), noise, inherent in AES spectra, this research also included experiments to create structures in materials, which were intended to suppress SE backgound noise in …

Bayesian Inference On Quantile Regression-Based Mixed-Effects Joint Models For Longitudinal-Survival Data From Aids Studies, Hanze Zhang

USF Tampa Graduate Theses and Dissertations

In HIV/AIDS studies, viral load (the number of copies of HIV-1 RNA) and CD4 cell counts are important biomarkers of the severity of viral infection, disease progression, and treatment evaluation. Recently, joint models, which have the capability on the bias reduction and estimates' efficiency improvement, have been developed to assess the longitudinal process, survival process, and the relationship between them simultaneously. However, the majority of the joint models are based on mean regression, which concentrates only on the mean effect of outcome variable conditional on certain covariates. In fact, in HIV/AIDS research, the mean effect may not always be of …

Investigating Marine Resources In The Gulf Of Mexico At Multiple Spatial And Temporal Scales Of Inquiry, Joshua Paul Kilborn

USF Tampa Graduate Theses and Dissertations

The work in this dissertation represents an attempt to investigate multiple temporal and spatial scales of inquiry relating to the variability of marine resources throughout the Gulf of Mexico large marine ecosystem (Gulf LME). This effort was undertaken over two spatial extents within the greater Gulf LME using two different time-series of fisheries monitoring data. Case studies demonstrating simple frameworks and best practices are presented with the aim of aiding researchers seeking to reduce errors and biases in scientific decision making. Two of the studies focused on three years of groundfish survey data collected across the West Florida Shelf (WFS), …

The Performance Of Multilevel Structural Equation Modeling (Msem) In Comparison To Multilevel Modeling (Mlm) In Multilevel Mediation Analysis With Non-Normal Data, Thanh Vinh Pham

USF Tampa Graduate Theses and Dissertations

The mediation analysis has been used to test if the effect of one variable on another variable is mediated by the third variable. The mediation analysis answers a question of how a predictor influences an outcome variable. Such information helps to gain understanding of mechanism underlying the variation of the outcome. When the mediation analysis is conducted on hierarchical data, the structure of data needs to be taken into account. Krull and MacKinnon (1999) recommended using Multilevel Modeling (MLM) with nested data and showed that the MLM approach has more power and flexibility over the standard Ordinary Least Squares (OLS) …

Resolving Chronological And Temperature Constraints On Antarctic Deglacial Evolution Through Improved Dating Methodology, Cristina Subt

USF Tampa Graduate Theses and Dissertations

In order to determine the timing of Antarctic ice sheet retreat and advance during the Late Quaternary, various tools are used to measure the age of marginal marine sediments. Carbonate 14C dating is a well-established approach, but requires foraminiferal microfossils, shells or other carbonate materials that are rare in most Antarctic regions, and may also suffer from vital effects, which can result in variability of up to 500 years in living organisms. Bulk acid insoluble organic (AIO) 14C dates are frequently as an alternative, but this approach works best where high productivity and sedimentation rates reign, and not too well …

Imaging Wetland Hydrogeophysics: Applications Of Critical Zone Hydrogeophysics To Better Understand Hydrogeologic Conditions In Coastal And Inland Wetlands And Waters, Christine Marie Downs

USF Tampa Graduate Theses and Dissertations

This dissertation consists of three projects utilizing electric and electromagnetic (EM) methods to better understand critical-zone hydrogeologic conditions in select Florida wetlands and waters.

First, a time-lapse electrical resistivity (ER) survey was conducted in section of mangrove forest on a barrier island in southeast Florida to image changes in pore-water salinity in the root zone. ER data show the most variability in the root zone over a 24-hour period, and, generally, the ground is more resistive during the day than overnight.

Second, a suite of three-dimensional forward models, based on varying lateral boundaries and conductivities typical of a coastal wetland, …

Design, Synthesis, Applications Of Polymers And Dendrimers, Alekhya Nimmagadda

USF Tampa Graduate Theses and Dissertations

WHO has reported that antibiotic resistance is the third major cause of human death all over the globe. Recent study, has focused on the development of new antibacterial resistance drugs. Herein, we tried to synthesis a series of polymers that can mimic the HDPs. HDPs can target the bacterial cell membrane and they have less chances to develop bacterial resistance. We synthesized the amphiphilic polycarbonates that are highly selective to Gram-positive bacteria, including multidrug resistant pathogens. The membrane disruption activity of these polymers was proved by fluorescence and TEM studies and the drug resistance study showed that the polymers don’t …

Metal-Organic Frameworks And Mof-Derived Carbon Materials For Fuel Cell Applications, Kia Williams

USF Tampa Graduate Theses and Dissertations

Rapid industrial globalization and technological development and energy consumption across the globe has significantly increased in response to mounting energy needs. The necessity for alternative and sustainable energy conversion devices has become apparent with the growth of energy utilization. In recent years, many research efforts have been made in the development of low-cost, efficient, environmentally friendly energy conversion devices. One type of energy conversion device, polymer electrolyte membrane fuel cells (PEMFCs), uses hydrogen oxidation at the anode and oxygen reduction at the cathode, with a solid-state proton conducting membrane between to generate energy with water as a by-product. PEMFCs use …

Design And Synthesis Of Cpg-Lytic Peptide Conjugate, Brachytherapy Beads And A Combinatorial Library Of Primary Amines Used As Potential Therapeutics In The Treatment Of Cancers, Josanne-Dee Woodroffe

USF Tampa Graduate Theses and Dissertations

Cancer remains one of the most feared diseases affecting the modern world. Second to heart disease, it is the largest cause of deaths, affecting one in three persons. Cancer cells are formed when normal, healthy cells become damage, losing their normal regulatory mechanism that control cell growth. There are many different types and progression of these cancer cells that determine the type of treatment a patient receives. The primary focus of this dissertation is to propose three studies of anticancer agents. In Chapter one, a CpG-lytic peptide conjugate was designed to target receptors on the cell membrane to concentrate the …

Generalized D-Kaup-Newell Integrable Systems And Their Integrable Couplings And Darboux Transformations, Morgan Ashley Mcanally

USF Tampa Graduate Theses and Dissertations

We present a new spectral problem, a generalization of the D-Kaup-Newell spectral problem, associated with the Lie algebra sl(2,R). Zero curvature equations furnish the soliton hierarchy. The trace identity produces the Hamiltonian structure for the hierarchy. Lastly, a reduction of the spectral problem is shown to have a different soliton hierarchy with a bi-Hamiltonian structure. The first major motivation of this dissertation is to present spectral problems that generate two soliton hierarchies with infinitely many commuting conservation laws and high-order symmetries, i.e., they are Liouville integrable.

We use the soliton hierarchies and a non-seimisimple matrix loop Lie algebra in order …

Sol-Gel Niobia-Based Sorbents For The Enrichment Of Organophosphorus Compounds By Capillary Microextraction Online Coupled To High Performance Liquid Chromatography, Sheshanka Kesani

USF Tampa Graduate Theses and Dissertations

Sample preparation is a key step in chemical analysis, and includes isolation of target analytes, removal of interferences, preconcentration, and/or modification of target analytes (if needed). Sample preparation is also the most time-consuming and error-prone step in the whole analytical process. Traditional sample preparation techniques involve hazardous solvents. Considering the environmental and health safety, it is desirable to reduce or eliminate organic solvents in sample preparation. Solid phase microextraction (SPME) was introduced as a solvent free sample preparation technique. Capillary microextraction (CME) is one of the formats of SPME that can be easily coupled to high performance liquid chromatography (HPLC). …

Manipulating Electromagnetic Waves With Enhanced Functionalities Using Nonlinear And Chiral Metamaterials, Sinhara Rishi Malinda Silva

USF Tampa Graduate Theses and Dissertations

Metamaterials are artificial structures, which periodically arranged to exhibit fascinating electromagnetic properties, not existing in nature. A great deal of research in the field of metamaterial was conducted in a linear regime, where the electromagnetic responses are independent of the external electric or magnetic fields. Unfortunately, in linear regime the desired properties of metamaterials have only been achieved within a narrow bandwidth, around a fixed frequency. Therefore, nonlinearity is introduced into metamaterials by merging meta-atoms with well-known nonlinear materials. Nonlinear metamaterials are exploited in this dissertation to introduce and develop applications in microwave frequency with broadband responses. The nonlinearity was …

Studies Of Polyacrylate Based Nanoparticle Emulsions, Faeez Mahzamani

USF Tampa Graduate Theses and Dissertations

Self-stabilizing polyacrylate nanoparticle emulsions were previously investigated in the Turos laboratory, and provided a new model for delivering antibiotics via encapsulation or covalent binding of the desired bioactive compound within the polymer nanoparticles. The method used the in water, free radical emulsion polymerization of butyl acrylate/styrene mixture to form the polymer chain stabilized with a surfactant. Current research in this dissertation further explores the versatility of related nanoparticle emulsion systems. Chapter 2 provides an overview of the loading of certain therapeutic drugs, such as 5-aminosalicylic acid and derivatives thereof, for the treatment of irritable bowel syndrome. Chapter 3 explores homo-polymer …

Growth, Characterization, And Function Of Ferroelectric, Ferromagnetic Thin Films And Their Heterostructures, Mahesh Hordagoda

USF Tampa Graduate Theses and Dissertations

With recent trends in miniaturization in the electronics sector, ferroelectrics have gained popularity due to their applications in non-volatile RAM. Taking one step further researchers are now exploring multiferroic devices that overcome the drawbacks of ferroelectric (FE) and ferromagnetic (FM) RAM’s while retaining the advantages of both. The work presented in this dissertation focuses on the growth of FE and FM thin film structures. The primary goals of this work include, (1) optimization of the parameters in the pulsed laser deposition (PLD) of FE and FM films and their heterostructures, (2) development of a structure-property relation that leads to enhancements …

Experimental Study Of High-Temperature Range Latent Heat Thermal Energy Storage, Chatura Wickramaratne

USF Tampa Graduate Theses and Dissertations

Among all thermal energy storage (TES) systems, latent heat thermal energy storage (LHTES) attracts high interest due to its high energy density and high exergetic efficiency. Due to the high enthalpy of fusion and low cost, inorganic salts are becoming popular as phase change materials and are used as the storage media in LHTES systems. The main drawbacks for the inorganic salts are their low thermal conductivity and high reactivity above 500°C. Therefore, designing a cost-effective containment at these conditions with longevity is a challenge. Macro-encapsulation of the PCM is one way to solve both the PCM containment issue as …

Application Of Metamaterials To Rf Energy Harvesting And Infrared Photodetection, Clayton M. Fowler

USF Tampa Graduate Theses and Dissertations

Techniques for adapting metamaterials for the improvement of RF energy harvesting and infrared photodetection are demonstrated using experimental and computer simulation methods. Two methods for RF energy harvesting are experimentally demonstrated and supported by computer simulation. In the first method, a metamaterial perfect absorber (MPA) is made into a rectenna capable of harvesting RF energy and delivering power to a load by soldering Schottky diodes onto connected split ring resonator (SRR) structures composing the planar metasurface of the perfect absorber. The metamaterial rectenna is accompanied by a ground plane placed parallel to it, which forms a Fabry-Perot cavity between the …

Surfaces And Epitaxial Films Of Corundum-Structured Mixed Metal Oxides., Alan Richard Kramer

USF Tampa Graduate Theses and Dissertations

Throughout the last half century of materials science, significant motivations came from, and still do, the industrial applications of these materials. Whether it is electronic, thermal, tribological or chemical in nature, the study of metals, semiconductors and insulators eventually reveals that the surface plays a significant part in the properties of these materials. Understanding metal terminations reveals often that an oxide is the stable state of the metallic surface in an ambient atmosphere and the ability to predict and control these oxides has led to significant strides forward in not just the metallic bulk but the oxide as well.

Here …

Statistical Analysis And Modeling Of Stomach Cancer Data, Chao Gao

USF Tampa Graduate Theses and Dissertations

The objective of this study is to address some important questions associated with stomach cancer patients using the data from the Surveillance Epidemiology and End Results (SEER) program of the United States. To better understand the behavior of stomach cancer, we first perform parametric analysis for each patient group (white male, white female, African American male, African American female, other male and female) to identify the probability distribution function which can best characterize the behavior of the malignant stomach tumor sizes. We evaluate the effects of patients’ age, gender and race on the malignant stomach tumor sizes by developing quantile …

Improving Service Level Of Free-Floating Bike Sharing Systems, Aritra Pal

USF Tampa Graduate Theses and Dissertations

Bike Sharing is a sustainable mode of urban mobility, not only for regular commuters but also for casual users and tourists. Free-floating bike sharing (FFBS) is an innovative bike sharing model, which saves on start-up cost, prevents bike theft, and offers significant opportunities for smart management by tracking bikes in real-time with built-in GPS. Efficient management of a FFBS requires: 1) analyzing its mobility patterns and spatio-temporal imbalance of supply and demand of bikes, 2) developing strategies to mitigate such imbalances, and 3) understanding the causes of a bike getting damaged and developing strategies to minimize them. All of these …

Multi-Step Tokenization Of Automated Clearing House Payment Transactions, Privin Alexander

USF Tampa Graduate Theses and Dissertations

Since its beginnings in 1974, the Automated Clearing House (ACH) network has grown into one of the largest, safest, and most efficient payment systems in the world. An ACH transaction is an electronic funds transfer between bank accounts using a batch processing system.

Currently, the ACH Network moves almost $43 trillion and 25 billion electronic financial transactions each year. With the increasing movement toward an electronic, interconnected and mobile infrastructure, it is critical that electronic payments work safely and efficiently for all users. ACH transactions carry sensitive data, such as a consumer's name, account number, tax identification number, account holder …

On Extending Hansel's Theorem To Hypergraphs, Gregory Sutton Churchill

USF Tampa Graduate Theses and Dissertations

For integers $n \geq k \geq 2$, let $V$ be an $n$-element set, and let $\binom{V}{k}$ denote the family of all $k$-element subsets of $V$. For disjoint subsets $A, B \subseteq V$, we say that $\{A, B\}$ {\it covers} an element $K \in \binom{V}{k}$ if $K \subseteq A \dot\cup B$ and $K \cap A \neq \emptyset \neq K \cap B$. We say that a collection $\cC$ of such pairs {\it covers} $\binom{V}{k}$ if every $K \in \binom{V}{k}$ is covered by at least one $\{A, B\} \in \cC$. When $k=2$, covers $\cC$ of $\binom{V}{2}$ were introduced in~1961 by R\'enyi~\cite{Renyi}, where they …

The Ecology Of Antibiotic Resistance: Sources And Persistence Of Vancomycin-Resistant Enterococci And Antibiotic Resistant Genes In Aquatic Environments, Suzanne M. Young

USF Tampa Graduate Theses and Dissertations

The growing crisis of antibiotic resistance is a major threat to ecosystems and human health. Infections caused by known and emerging antibiotic resistant pathogens are on the rise globally, with approximately 700,000 deaths per year caused by antibiotic resistant bacteria (1). In the United States, infections from antibiotic resistant bacteria cause more than 2 million illnesses and 23,000 deaths (2). Antibiotic resistant bacteria and antibiotic resistance genes are released into aquatic ecosystems through hospital waste, residential sewer lines and animal agricultural waste streams. Animal agriculture accounts for approximately 70% of antibiotic use in the United States (3). In agricultural ecosystems, …

Evaluating Satellite And Supercomputing Technologies For Improved Coastal Ecosystem Assessments, Matthew James Mccarthy

USF Tampa Graduate Theses and Dissertations

Water quality and wetlands represent two vital elements of a healthy coastal ecosystem. Both experienced substantial declines in the U.S. during the 20^th century. Overall coastal wetland cover decreased over 50% in the 20^th century due to coastal development and water pollution. Management and legislative efforts have successfully addressed some of the problems and threats, but recent research indicates that the diffuse impacts of climate change and non-point source pollution may be the primary drivers of current and future water-quality and wetland stress. In order to respond to these pervasive threats, traditional management approaches need to adopt modern …

Constructing A Clinical Research Data Management System, Michael C. Quintero

USF Tampa Graduate Theses and Dissertations

Clinical study data is usually collected without knowing what kind of data is going to be collected in advance. In addition, all of the possible data points that can apply to a patient in any given clinical study is almost always a superset of the data points that are actually recorded for a given patient. As a result of this, clinical data resembles a set of sparse data with an evolving data schema. To help researchers at the Moffitt Cancer Center better manage clinical data, a tool was developed called GURU that uses the Entity Attribute Value model to handle …

Strong-Dism: A First Attempt To A Dynamically Typed Assembly Language (D-Tal), Ivory Hernandez

USF Tampa Graduate Theses and Dissertations

Dynamically Typed Assembly Language (D-TAL) is not only a lightweight and effective solution to the gap generated by the drop in security produced by the translation of high-level language instructions to low-level language instructions, but it considerably eases up the burden generated by the level of complexity required to implement typed assembly languages statically. Although there are tradeoffs between the static and dynamic approaches, focusing on a dynamic approach leads to simpler, easier to reason about, and more feasible ways to understand deployment of types over monomorphically-typed or untyped intermediate languages. On this occasion, DISM, a simple but powerful and …

The Ability Of The U.S. Army Heat Strain Decision Aid (Hsda) To Predict A Limiting Heat Stress Exposure, Katelynn E. Glisson

USF Tampa Graduate Theses and Dissertations

Working below the threshold limit value (TLV) for heat stress is not always feasible. When work above the TLV is required, an exposure method is needed that can help protect workers from time limiting heat stress by calculating a safe time for work at certain heat exposures. The purpose of this paper is to determine whether the USARIEM Heat Strain Decision Aid (HSDA) can be used to predict time limiting heat stress exposure in an occupational setting.

Twelve adults participated in time limited heat stress exposures. A range of heat stress conditions were designed using three different ensembles and five …

Predicting Hand Surface Area From A Two-Dimensional Hand Tracing, Myles O'Mara

USF Tampa Graduate Theses and Dissertations

Recent occupational health studies have focused on dermal exposure at the hands, but have been unable to accurately express dose without knowing the HSA. There is no standard method to calculate HSA, though some researchers have derived HSA formulas based on dimensions from a Taiwanese population. This research paper describes a shortcut method to estimate the hand surface area (HSA) of a human hand from a two-dimensional hand tracing, and repeated a Taiwanese HSA study in order to explore the viability of its HSA formula in an American university population. A sample of nine adult men and nine adult women, …