Digital Commons Network^™

A Hybrid Dynamic Modeling Of Time-To-Event Processes And Applications, Emmanuel A. Appiah

USF Tampa Graduate Theses and Dissertations

In the survival and reliability data analysis, parametric and nonparametric methods are used to estimate the hazard/risk rate and survival functions. A parametric approach is based on the assumption that the underlying survival distribution belongs to some specific family of closed form distributions (normal, Weibull, exponential, etc.). On the other hand, a nonparametric approach is centered around the best-fitting member of a class of survival distribution functions. Moreover, the Kaplan-Meier and Nelson-Aalen type nonparametric approach do not assume either distribution class or closed-form distributions. Historically, well-known time-to-event processes are death of living specie in populations and failure of component in …

Statistical Analysis And Modeling Of Cyber Security And Health Sciences, Nawa Raj Pokhrel

USF Tampa Graduate Theses and Dissertations

Being in the era of information technology, importance and applicability of analytical statistical model an interdisciplinary setting in the modern statistics have increased significantly. Conceptually understanding the vulnerabilities in statistical perspective helps to develop the set of modern statistical models and bridges the gap between cybersecurity and abstract statistical /mathematical knowledge. In this dissertation, our primary goal is to develop series of the strong statistical model in software vulnerability in conjunction with Common Vulnerability Scoring System (CVSS) framework. In nutshell, the overall research lies at the intersection of statistical modeling, cybersecurity, and data mining. Furthermore, we generalize the model of …

A Behavioral Analysis Of Households Using Reclaimed Water In Irrigation: Case Of Pinellas County, Florida, Natalie Kuraya-Ziyadeh

USF Tampa Graduate Theses and Dissertations

In order to tend to the world’s dwindling freshwater supplies, sustainable alternative methods need to be integrated in order to keep up with the world’s increasing demand. Reclaimed water (RW) is one of the sustainable methods adopted by some Floridian cities such as Tampa, Tallahassee, and St. Pete that provide an alternative water source for non-potable uses. However, despite this alleviating effect RW has on freshwater supplies, it is crucial to recognize the potential harm it poses on neighboring waterbodies due to the residual contaminants it still contains, including Nitrogen (N) and Phosphorous (P). As such, studying residents’ knowledge and …

Orthogonal Polynomials With Respect To The Measure Supported Over The Whole Complex Plane, Meng Yang

USF Tampa Graduate Theses and Dissertations

In chapter 1, we present some background knowledge about random matrices, Coulomb gas, orthogonal polynomials, asymptotics of planar orthogonal polynomials and the Riemann-Hilbert problem. In chapter 2, we consider the monic orthogonal polynomials, $\{P_{n,N}(z)\}_{n=0,1,\cdots},$ that satisfy the orthogonality condition,

\begin{equation}\nonumber \int_\mathbb{C}P_{n,N}(z)\overline{P_{m,N}(z)}e^{-N Q(z)}dA(z)=h_{n,N}\delta_{nm} \quad(n,m=0,1,2,\cdots), \end{equation}

where $h_{n,N}$ is a (positive) norming constant and the external potential is given by

$$Q(z)=|z|^2+ \frac{2c}{N}\log \frac{1}{|z-a|},\quad c>-1,\quad a>0.$$

The orthogonal polynomial is related to the interacting Coulomb particles with charge $+1$ for each, in the presence of an extra particle with charge $+c$ at $a.$ For $N$ large and a fixed ``c'' this …

Non-Equilibrium Phase Transitions In Interacting Diffusions, Wael Al-Sawai

USF Tampa Graduate Theses and Dissertations

The theory of thermodynamic phase transitions has played a central role both in theoretical physics and in dynamical systems for several decades. One of its fundamental results is the classification of various physical models into equivalence classes with respect to the scaling behavior of solutions near the critical manifold. From that point of view, systems characterized by the same set of critical exponents are equivalent, regardless of how different the original physical models might be. For non-equilibrium phase transitions, the current theoretical framework is much less developed. In particular, an equivalent classification criterion is not available, thus requiring a specific …

Towards Utilization Of Distributed On-Chip Power Delivery Against Em Side-Channel Attacks, Ahmed Waheed Khan

USF Tampa Graduate Theses and Dissertations

Non-invasive side-channel attacks (SCAs) are potent attacks on a cryptographic circuit that can reveal its secret key without requiring lots of equipment. EM side-channel leakage is typically the derivative of the power consumption profile of a circuit. Since the fluctuations of the supply voltage strongly depend on the topology and features of the power distribution network (PDN), design of the PDN has a direct impact on EM side-channel leakage signature.

In this thesis, we explore the security implications of distributed on-chip voltage regulators against EM side-channel attacks. Extensive HFSS simulations have demonstrated that the maximum EM radiation can be reduced …

Studies Aimed At The Synthesis Of Anti-Infective Agents, Ankush Kanwar

USF Tampa Graduate Theses and Dissertations

Infectious diseases continue to be a major concern worldwide. They are the second leading cause of death after heart disease. Factors such as an increasing global population, travel, urbanization, global climate change and evolution of pathogens have made infectious diseases more common. Infectious diseases, particularly neglected tropical diseases (NTDs) result in many deaths worldwide. Malaria and leishmaniasis are two common (NTDs) which affect low income countries around the globe. Low cost drugs with novel mechanism of action are required to tackle the growing resistances of parasites against current drugs used in the developing world, where most of the cases occur. …

Spatial Dynamics And Productivity Of A Gulf Of Mexico Commercial Reef Fish Fishery Following Large Scale Disturbance And Management Change, Marcy Lynn Cockrell

USF Tampa Graduate Theses and Dissertations

The Gulf of Mexico commercial reef fish fishery has experienced significant management changes and disturbance in recent years, including transitioning two major fisheries from a traditional open access system into a limited entry individual fishing quota (IFQ) system in 2007 and 2010. Also in 2010, the Deepwater Horizon oil spill (DWH) released an estimated 4.9 million barrels of oil into the Gulf (~206 million U.S. gallons), and is still the largest U.S. environmental disaster to date. Emergency fishing closures initiated shortly after the oil spill began were successful in keeping tainted seafood from reaching markets. However, effects of DWH closures …

The Association Of Size Variation In The Dental Arch To Third Molar Agenesis For A Modern Population, Devin N. Williams

USF Tampa Graduate Theses and Dissertations

The frequency with which individuals do not develop their third molars, or wisdom teeth, is increasing worldwide. This current topic of human evolution is relevant to the research of anthropologists, geneticists, dentists, and other researchers involved in the study of human dentition. Many explanations have been offered to account for the prevalence of molar agenesis including, evolutionary, environmental, and genetic theories. The purpose of this research project is to determine the frequency of third molar agenesis and investigate the relationship between third molar agenesis and maxillomandibular jaw dimensions in a sample of orthodontic patients. This research tests the hypotheses that: …

Hume On The Doctrine Of Infinite Divisibility: A Matter Of Clarity And Absurdity, Wilson H. Underkuffler

USF Tampa Graduate Theses and Dissertations

I provide an interpretation of Hume’s argument in Treatise 1.2 Of the Ideas of Space and Time that finite extensions are only finitely divisible (hereafter Hume’s Finite Divisibility Argument). My most general claim is that Hume intends his Finite Divisibility Argument to be a demonstration in the Early Modern sense as involving the comparison and linking of ideas based upon their intrinsic contents. It is a demonstration of relations among ideas, meant to reveal the meaningfulness or absurdity of a given supposition, and to distinguish possible states of affairs from impossible ones. It is not an argument ending in an …

Extending Spectrophotometric Pht Measurements In Coastal And Estuarine Environments, Nora Katherine Douglas

USF Tampa Graduate Theses and Dissertations

Nearshore and estuarine environments play a vital role in the cycling of carbon, but the effects of ocean acidification in estuarine waters have not been studied as extensively as in the open ocean. One reason for this is the limitation of pH measurement capabilities in low-salinity waters. Typically, pH in these environments has been measured using potentiometric methods that are subject to uncertainties on the order of 0.01. Spectrophotometric methods for measuring pHT offer precision and accuracy superior to those of potentiometric methods. However, previous characterizations for purified sulfonephthalein indicators, used for marine spectrophotometric measurements, are not applicable to estuarine …

Evaluation Of Academic And Social Engagement In A Technology-Based Collaborative Approach To Inclusive Geoscience Field Learning, Anita Marie Stone Marshall

USF Tampa Graduate Theses and Dissertations

Field learning is an important aspect of geoscience education to teach or reinforce concepts and skills, and the highly social experience of field work can improve learning outcomes, create networks to support future academic success, and promote a sense of belonging in the geosciences. However, field learning presents significant barriers to participation for students with physical disabilities. The introduction of digital data collection and communication devices into traditional field work settings has created new opportunities to expand access to field learning experiences such as remote collaboration; a method of undertaking field work through collaborative teamwork and the use of digital …

From Florida To Antarctica: Dereplication Strategies And Chemical Investigations Of Marine Organisms, Matthew A. Knestrick

USF Tampa Graduate Theses and Dissertations

In the fight against disease and illness, nature has provided mankind some of our best therapeutics in the form of secondary metabolites. The plant, fungi and animal phyla inhabiting the Earth produce diverse and unique chemistry that can be used in our fight against disease. In the growing threat of drug resistance and pathogen evolution, the field of natural products chemistry strives to explore new biological and chemical diversity sources, and develop innovative methodology to identify and isolate new chemistry faster than ever.

The dissertation herein presented is one such effort to find new, bioactive chemistry from the marine environments. …

Azamacrocyclic-Based Frameworks: Syntheses And Characterizations, Chavis Andrew Stackhouse

USF Tampa Graduate Theses and Dissertations

Research in metal-organic frameworks (MOFs) has risen greatly in recent decades Owing to their unequaled potential tunability and structural diversity. MOFs may be described as crystalline structures composed of metal cations or clusters of cations, commonly referred to as secondary building units (SBUs), and custom-designed organic ligands. The variety of structural motifs, ligands, and SBUs that may be incorporated promote the attainment of essentially countless potential MOFs and application in numerous areas of interest, such as gas adsorption, catalysis, gas separation, and sensing. Further functionalization of MOF materials by means of post-synthetic modification(PSM)33–37 of metal clusters or organic ligands, constructing …

Conformational Fluctuations Of Biomolecules Studied Using Molecular Dynamics And Enhanced Sampling, Geoffrey M. Gray

USF Tampa Graduate Theses and Dissertations

Biomolecule structural fluctuations determine function, regulating numerous biological processes My research has shed light on several interesting cases in which structural fluctuations have been identified to assess functional differences. Chapter 2 discusses the effects of structural rearrangement of the β2-β3 loop on the DNA binding affinity of the type 6 human papillomavirus E2 protein. Chapter 3 investigates the effects of phosphorylation on the C-terminal domain of Cdc37, a protein important in the Hsp90 chaperone cycle. Chapter 4 studies the effects on cyclycization on the conformational fluctuations of a γ-AApeptide used for high-throughput libraries. Chapter 5 is a structural study on …

Identification Of Individuals From Ears In Real World Conditions, Earnest Eugene Hansley

USF Tampa Graduate Theses and Dissertations

A number of researchers have shown that ear recognition is a viable alternative to more common biometrics such as fingerprint, face and iris because the ear is relatively stable over time, the ear is non-invasive to capture, the ear is expressionless, and both the ear’s geometry and shape have significant variation among individuals. Researchers have used different approaches to enhance ear recognition. Some researchers have improved upon existing algorithms, some have developed algorithms from scratch to assist with recognizing individuals by ears, and some researchers have taken algorithms tried and tested for another purpose, i.e., face recognition, and applied them …

"We're Not Going To Talk About That:" A Qualitative Case Study Of Three Elementary Teachers' Experiences Integrating Literacy And Social Studies, Rebecca L. Powell

USF Tampa Graduate Theses and Dissertations

The purpose of this interpretive, qualitative multi-case study (Merriam, 2001; Stake, 1995) was to describe the experiences of three elementary classroom teachers as they integrated literacy and social studies during their literacy instruction. This study was grounded in an interpretivist paradigm and a theoretical lens of symbolic interactionism. The guiding questions were: What are the experiences of three elementary teachers when integrating literacy and social studies instruction? What information do teachers use when making decisions about integrated instruction? How do teachers’ beliefs align with their practices? How do teachers organize, plan for, and provide integrated instruction, including how they use …

Characterization Of Nylon-12 In A Novel Additive Manufacturing Technology, And The Rheological And Spectroscopic Analysis Of Peg-Starch Matrix Interactions, Garrett Michael Craft

USF Tampa Graduate Theses and Dissertations

In this work differential scanning calorimetry, dynamic mechanical analysis, Fourier-Transformed Infrared Spectroscopy [FT-IR] and polarized light microscopy will be employed to characterize polymeric systems. The first chapter broadly covers polymer synthesis and important characterization methods.

In the second chapter, a polyamide (PA12) will be sintered via a novel additive manufacturing (AM) technology developed here at USF termed LAPS (Large Area Projection Sintering). LAPS uses extended sintering timespans to ensure complete melting and densification of the polymer powder over the entire two-dimensional area of the part’s footprint. Further, it allows for the printed layer to crystallize and shrink in its entirety …

Characterization Of Computed Tomography Radiomic Features Using Texture Phantoms, Muhammad Shafiq Ul Hassan

USF Tampa Graduate Theses and Dissertations

Radiomics treats images as quantitative data and promises to improve cancer prediction in radiology and therapy response assessment in radiation oncology. However, there are a number of fundamental problems that need to be solved in order to potentially apply radiomic features in clinic. The first basic step in computed tomography (CT) radiomic analysis is the acquisition of images using selectable image acquisition and reconstruction parameters. Radiomic features have shown large variability due to variation of these parameters. Therefore, it is important to develop methods to address these variability issues in radiomic features due to each CT parameter. To this end, …

Elastin-Like Polypeptide Fusion Tag As A Protein-Dependent Solubility Enhancer Of Cysteine-Knot Growth Factors, Tamina L. Johnson

USF Tampa Graduate Theses and Dissertations

Elastin-like peptide (ELP) fusions promote therapeutic delivery and efficacy. Recombinant proteins, like neurotrophins, lack bioavailability, have short in vivo half-lives, and require high manufacturing costs. Fusing recombinant proteins with genetically encodable ELPs will increase bioavailability, enhance in vivo solubilization, as well as provide a cost-effective method for purification without the need for chromatography. During expression of neurotrophin-ELP (N-ELP) fusions, dense water-insoluble aggregates known as inclusion bodies (IBs) are formed. Inclusion bodies are partially and misfolded proteins that usually require denaturants like Urea for solubilization. Strong denaturants arrest ELPs stimuli-responsive property and increase unwanted aggregation, making purification difficult, yet possible. The …

Coarse-Grained Modeling Studies Of Polymeric And Granular Systems, Hong Trung Nguyen

USF Tampa Graduate Theses and Dissertations

This Dissertation is devoted to computational study of the solidification, dynamics and mechanics of model semiflexible polymers with variable chain flexibility as well as a computational investigation of the clogging phenomena observed in granular materials.

Chain stiffness is an intrinsic factor that governs single-chain flexibility. It plays a critical role in the physics of polymeric materials. In this work, we employ a coarse-grained polymer model in which chain stiffness can be tuned by a single parameter (bending stiffness kb) that yields chain shape ranging from coil-like to rod-like in the flexible and very stiff limit respectively. In chapter 2, we …

Synthesis Of Novel Agents For The Treatment Of Infectious And Neurodegenerative Diseases, Benjamin Joe Eduful

USF Tampa Graduate Theses and Dissertations

Infectious and neurodegenerative diseases continue to be a major concern worldwide. In spite of the great advances in drug therapy for treating various infectious and neurodegenerative diseases, there is still an urgent need for new and improved drugs due to increasing drug resistance among pathogens, emergence of new pathogens, ease of transmission of infections, ineffective available treatments, toxicity associated with current standard of care, aging populations and the lack of better alternative treatment options.

The first part of this manuscript (chapters 1 - 5) describes the synthesis of novel agents active against Leishmania donovani. According to the World Health Organization …

Computational Discovery Of Energetic Polynitrogen Compounds At High Pressure, Brad A. Steele

USF Tampa Graduate Theses and Dissertations

High-nitrogen-content energetic compounds containing multiple N-N bonds are an attractive alternative towards developing new generation of environmentally friendly, and more powerful energetic materials. High-N content translates into much higher heat of formation resulting in much larger energy output, detonation pressure and velocity upon conversion to large amounts of non-toxic, strongly bonded N2 gas. This thesis describes recent advances in the computational discovery of group-I alkali and hydrogen polynitrogen materials at high pressures using powerful first-principles evolutionary crystal structure prediction methods. This is highlighted by the discovery of a new family of materials that consist of long-sought after all-nitrogen N􀀀 5 …

Predictive Validity Of Florida’S Postsecondary Education Readiness Test, Alisa Murphy Žujović

USF Tampa Graduate Theses and Dissertations

The role of the community college is constantly evolving. At its inception in the early 1900’s, the community college’s broad focus was to provide quality, affordable education to the members of the community the college serves. Today, that focus remains the same, but has also morphed into one that meets the specific needs of its students. One of these needs that is a critical issue for community colleges relates to developmental education.

The assessment of developmental education has been a contentious subject among higher education institutions. Defining college readiness, methods describing how to measure it, and instruments with which to …

Flow And Transport In Low-Gradient Rivers And Estuaries, Hunter Lee Clasen

USF Tampa Graduate Theses and Dissertations

For this dissertation I studied flow and transport in low gradient Florida streams. Chapter 2 is a statewide analysis of long-term variations in stream discharge. The results from Chapter 2 suggest that changes in mean annual stream discharge are controlled by the Atlantic Multi-Decadal Oscillation (AMO). During the warm phase, mean annual discharge decreases in central Florida and increases in north Florida. The opposite is true during the cool phase, with mean annual discharge increasing in central Florida and decreasing in north Florida. This pattern is observed for both components of stream discharge, base flow and runoff.

The following two …

Climate Change: Aristotelian Virtue Theory, The Aidōs Response And Proper Primility, John W. Voelpel

USF Tampa Graduate Theses and Dissertations

Climate change is the first anthropogenic alteration of a global Earth system. It is globally catastrophic in terms of food production, sea level rise, fresh water availability, temperature elevation, ocean acidification, species disturbance and destruction to name just a few crisis concerns. In addition, while those changes are occurring now, they are amplifying over decadal periods and will last for centuries and possibly millennia. While there are a number of pollutants involved, carbon dioxide (CO2) which results from the combustion of any fossil fuel is the primary pollutant. It has not been considered a pollutant until recently because of its …

A Fall Prevention System For The Elderly And Visually Impaired, Yueng Santiago De La Hoz Isaza

USF Tampa Graduate Theses and Dissertations

The World Health Organization claims that there are more than 285 million blind and visually impaired people in the world. In the US, 25 million Americans suffer from total or partial vision loss. As a result of their impairment, they struggle with mobility problems, especially the risk of falling. According to the National Council On Aging, falls are among the primary causes for fatal injury and they are the most common cause of non-fatal trauma-related hospital admissions among older adults. Visibility, an organization that helps visually impaired people, reports that people with visual impairments are twice as likely to fall …

In Situ Extrinsic Doping Of Cdte Thin Films For Photovoltaic Applications, Imran Suhrid Khan

USF Tampa Graduate Theses and Dissertations

The Cadmium Telluride thin film solar cell is one of the leading photovoltaic technologies. Efficiency improvements in the past decade made it a very attractive and practical source of renewable energy. Considering the theoretical limit, there is still room for improvement, especially the cell’s open circuit voltage (VOC). To improve VOC, the p-type carrier concentration and minority carrier lifetime of the CdTe absorber needs to be improved. Both these parameters are directly related to the point defect distribution of the semiconductor, which is a function of deposition stoichiometry, dopant incorporation and post-deposition treatments.

CdTe films were deposited by the Elemental …

Dynamic Energy-Aware Database Storage And Operations, Peyman Behzadnia

USF Tampa Graduate Theses and Dissertations

Energy consumption has become a first-class optimization goal in design and implementation of data-intensive computing systems. This is particularly true in the design of database management systems (DBMS), which is one of the most important servers in software stack of modern data centers. Data storage system is one of the essential components of database and has been under many research efforts aiming at reducing its energy consumption. In previous work, dynamic power management (DPM) techniques that make real-time decisions to transition the disks to low-power modes are normally used to save energy in storage systems. In this research, we tackle …

Signal Detection Of Adverse Drug Reaction Using The Adverse Event Reporting System: Literature Review And Novel Methods, Minh H. Pham

USF Tampa Graduate Theses and Dissertations

One of the objectives of the U.S. Food and Drug Administration is to protect the public health through post-marketing drug safety surveillance, also known as Pharmacovigilance. An inexpensive and efficient method to inspect post-marketing drug safety is to use data mining algorithms on electronic health records to discover associations between drugs and adverse events.

The purpose of this study is two-fold. First, we review the methods and algorithms proposed in the literature for identifying association drug interactions to an adverse event and discuss their advantages and drawbacks. Second, we attempt to adapt some novel methods that have been used in …