Digital Commons Network^™

The Ability Of The U.S. Military’S Wbgt-Based Flag System To Recommend Safe Heat Stress Exposures, David R. Almario

USF Tampa Graduate Theses and Dissertations

The U.S. military currently uses a flag system based on wet-bulb globe temperature (WBGT) and metabolic rate to recommend heat stress exposure limits. This paper addresses the ability of the flag system to recommend safe heat exposures in a non-military population.

Two progressive heat stress studies provided data on 528 observations of safe or unsafe exposures of 4 hours over a range of WBGT conditions and metabolic rates using 29 participants wearing woven cotton clothing. For the two studies, range of WBGT conditions was 25 to 42C, and the range of metabolic rates was 100 to 650 watts. These exposures …

Parallelization Of Genetic Algorithm To Solve Max-3sat Problem On Gpus, Prakruthi Shivram

USF Tampa Graduate Theses and Dissertations

There are many combinatorial optimization problems such as flow shop scheduling, quadraticassignment problem, traveling salesman problem, that are computationally intractable. Genetic Algorithm is a heuristic algorithm used to find an answer to combinatorial optimization problems. MAX-3SAT is an example of combinatorial optimization problem which has wide range of applications as many real world problems can be translated to MAX-3SAT problem. Genetic algorithms are suitable to solve MAX-3SAT problems but usually undergo premature convergence. To prevent this convergence and maintain diversity, one possible solution is to use large population size. This increases computation cost and time. Since Genetic Algorithms compute the …

An Efficient Run-Time Cfi Check For Embedded Processors To Detect And Prevent Control Flow Based Attacks, Srivarsha Polnati

USF Tampa Graduate Theses and Dissertations

A popular software attack on a program is by transferring the program control to malicious code inserted into the program. Control Flow Integrity (CFI) check has been proposed as a detection mechanism for control flow deviation. In the context of embedded processors, this thesis proposes a novel approach to implement CFI to detect and stall under a control flow attack. We exploit the unused bits in an instruction word to embed a label that can be used to check CFI during runtime. Given a control flow graph, we embed a unique label in each instruction in a basic block such …

A Flexible, Natural Deduction, Automated Reasoner For Quick Deployment Of Non-Classical Logic, Trisha Mukhopadhyay

USF Tampa Graduate Theses and Dissertations

Automated Theorem Provers (ATP) are software programs which carry out inferences over logico-mathematical systems, often with the goal of finding proofs to some given theorem. ATP systems are enormously powerful computer programs, capable of solving immensely difficult problems. Currently, many automated theorem provers exist like E, vampire, SPASS, ACL2, Coq etc. However, all the available theorem provers have some common problems: (1) Current ATP systems tend not to try to find proofs entirely on their own. They need help from human experts to supply lemmas, guide the proof, etc. (2) There is not a single proof system available which provides …

Social Constructionism And Cultivation Theory In Development Of The Juvenile “Super-Predator”, Elizabeth R. Jackson-Cruz

USF Tampa Graduate Theses and Dissertations

The myth of the “super-predator” offender was adopted by newspaper media in the mid-1990s characterizing “violent”, urban, and minority juvenile offenders. The phrase originated from newspaper headlines of the 1980s and 1990s, but limited research has identified whether this con-struct predated DiIulio and Fox’s crime surge prediction. This study sampled juvenile crime news items from The Chicago Tribune, The Los Angeles Times and The New York Times (N=2,008) 1985-1995 with defined search criteria of juvenile actors, “violent” juvenile crime, and/or juvenile drug crime. A descriptive analysis of the data determined reporting trends sought for a “period effect” caused by the …

Reference Dependence In Bayesian Reasoning, Alaina N. Talboy

USF Tampa Graduate Theses and Dissertations

The purpose of this dissertation is to examine aspects of the representational and computational influences on Bayesian reasoning as they relate to reference dependence. Across three studies, I explored how dependence on the initial problem structure influences the ability to solve Bayesian reasoning tasks. Congruence between the problem and question of interest, response errors, and individual differences in numerical abilities was assessed. The most consistent and surprising finding in all three experiments was that people were much more likely to utilize the superordinate value as part of their solution rather than the anticipated reference class values. This resulted in a …

An Evaluation Of Khan Academy Videos As A Supplement To Teacher Instruction For Elementary-Aged Students With Disabilities, Jacy M. Reed

USF Tampa Graduate Theses and Dissertations

Research has indicated video-based interventions are successful at teaching skills to individuals with varying types of disabilities. However, there is a gap in the literature regarding video-based intervention, such as video modeling, as an evidence-based practice for academic skills. As technology becomes more and more integrated into U.S. classrooms each year, it is important to evaluate the effectiveness of these interventions. Khan Academy videos are often used as supplemental resources by teachers to assist students with math work. The purposes of this study were to evaluate if in-class viewing of Khan Academy video models would increase math quiz performance for …

Empirical Analysis Of A Cybersecurity Scoring System, Jaleel Ahmed

USF Tampa Graduate Theses and Dissertations

In the field of cybersecurity, the top-level management make use of metrics to decide if the organization is doing well to protect itself from cyber attacks or is in tatters leaving itself susceptible against the vast threats looming around. Not only that but metrics are even used to measure the performance of the security team. The aim of this thesis is to show how economics is closely related to cybersecurity and how metrics play an important role in policy making of an organization. Furthermore, I scrutinize one of the leading security score providers for the way they detect botnet infection. …

Modeled Affinity Constants For Phosphorus Adsorption And Desorption Due To Saltwater Intrusion, Yasemin Taşcı

USF Tampa Graduate Theses and Dissertations

It is important to understand the processes that regulate phosphorus (P) fluxes to coastal environments, because P is an important nutrient in coastal ecosystems. Phosphorus adsorbs to the surface of minerals in sediment and bedrock, and an influx of seawater can cause some of that P to desorb, raising the P concentration of ambient water. Although seawater-induced P desorption is thought to be an important source of P to coastal environments, the chemical reactions that underlie it have not been established. Previous work provides some relevant surface reactions and associated affinity constants between various aqueous P species and the surface …

Field Quantization For Radiative Decay Of Plasmons In Finite And Infinite Geometries, Maryam Bagherian

USF Tampa Graduate Theses and Dissertations

We investigate field quantization in high-curvature geometries. The models and calculations can help with understanding the elastic and inelastic scattering of photons and electrons in nanostructures and probe-like metallic domains. The results find important applications in high-resolution photonic and electronic modalities of scanning probe microscopy, nano-optics, plasmonics, and quantum sensing.

Quasistatic formulation, leading to nonretarded quantities, is employed and justified on the basis of the nanoscale, here subwavelength, dimensions of the considered domains of interest.

Within the quasistatic framework, we represent the nanostructure material domains with frequency-dependent dielectric functions. Quantities associated with the normal modes of the electronic systems, the …

Regeneration Of Trace Metals During Phytoplankton Decay: An Experimental Study, Adrienne P. Hollister

USF Tampa Graduate Theses and Dissertations

Trace metals act as important nutrients, and sometimes toxins, to phytoplankton and other marine microorganisms. When phytoplankton decay, the elements in their cells are released back into the water column through regeneration (also referred to as remineralization), one of the processes responsible for governing concentrations of dissolved trace metals and macronutrients in depth profiles. In order to experimentally study regeneration, controlled experimental incubations of mixed phytoplankton assemblages from the Gulf of Mexico (GoM) and monocultures of the diatom Pseudo-nitzschia dolorosa and the dinoflagellate Karenia brevis were placed in the dark and monitored as they decayed with naturally present bacteria. Over …

An Assessment Of The Influence Of Local Conditions On The Economic And Environmental Sustainability Of Drain Water Heat Recovery Systems, Anusha Ravichandran

USF Tampa Graduate Theses and Dissertations

Increasing resource demand and decreasing supplies necessitate a paradigm shift in wastewater management from treatment to resource recovery. As the economic and environmental performance of wastewater-based resource recovery systems is location-specific (e.g., terrain slope influences hydro-energy recovery), a holistic view of their sustainability requires a comprehensive analysis on the effect of the local conditions on these systems. Although the internal factors affecting such systems (e.g., water quality and end use) are well studied, there is limited literature on the effect of external factors such as topography, climate and population density. This study evaluated the role of climate and population density …

How Mentors At Starting Right Now Build Relationships With Homeless Youth: A Qualitative Analysis, Sheena Hera

USF Tampa Graduate Theses and Dissertations

Although research has described mentoring programs to have positive effects with youth, there are few studies that describe how mentors build relationships with homeless youth. In this study, I sought to explore how mentors of a community-based organization, Starting Right Now, built relationships with homeless youth. Starting Right Now is a multi-faceted, community-based intervention developed in 2009 in Tampa, FL. They provide services to homeless adolescents who are no longer living in the custody of a parent or guardian. The program provides residential, educational, recreational, and professional development services, as well as mental and physical health care. Additionally each youth …

Timing And Rates Of Events In The Generic Volcanic Earthquake Swarm Model, Tianyu Rong

USF Tampa Graduate Theses and Dissertations

In this thesis I combine data from 29 volcanic earthquake swarms that follow the pattern predicted by the Generic Volcanic Earthquake Swarm Model (GVESM; Benoit and McNutt, 1996) to investigate whether the relative timing of various parameters of pre-eruptive volcanic earthquake swarms could be used to forecast the time of an impending eruption. Based on the analysis of seismic unrest preceding many eruptions, the GVESM suggests that it is common to see an increase first in high-frequency earthquakes, then low-frequency earthquakes, then the onset of volcanic tremor. While this pattern is useful to volcano-seismologists, the relative timing and durations of …

A Historical Approach To Understanding Explanatory Proofs Based On Mathematical Practices, Erika Oshiro

USF Tampa Graduate Theses and Dissertations

My dissertation focuses on mathematical explanation found in proofs looked at from a historical point of view, while stressing the importance of mathematical practices. Current philosophical theories on explanatory proofs emphasize the structure and content of proofs without any regard to external factors that influence a proof’s explanatory power. As a result, the major philosophical views have been shown to be inadequate in capturing general aspects of explanation. I argue that, in addition to form and content, a proof’s explanatory power depends on its targeted audience. History is useful here, because from it, we are able to follow the transition …

Detecting Rtl Trojans Using Artificial Immune Systems And High Level Behavior Classification, Farhath Zareen

USF Tampa Graduate Theses and Dissertations

Security assurance in a computer system can be viewed as distinguishing between self and non-self. Artificial Immune Systems (AIS) are a class of machine learning (ML) techniques inspired by the behavior of innate biological immune systems, which have evolved to accurately classify self-behavior from non-self-behavior. This work aims to leverage AIS-based ML techniques for identifying certain behavioral traits in high level hardware descriptions, including unsafe or undesirable behaviors, whether such behavior exists due to human error during development or due to intentional, malicious circuit modifications, known as hardware Trojans, without the need fora golden reference model. We explore the use …

Exploring The Behavior Of Model Fit Criteria In The Bayesian Approximate Measurement Invariance: A Simulation Study, Abeer Atallah S. Alamri

USF Tampa Graduate Theses and Dissertations

Measurement invariance (MI) is conducted to ensure that differences found in the results of group comparisons are due to true substantive differences and not methodological artifacts. Previous cross-cultural and cross-national studies with large number of groups showed that the advanced measurement invariance level was rarely held when utilizing the traditional (frequentist) MI approach. The Bayesian approximate measurement invariance (BAMI) was introduced to override the traditional MI strict assumption, because trivial non-invariance in parameters across groups is allowed. Although the concept of the BAMI, which has been utilized since 2013, was incorporated into the context of structural equation modeling, there is …

Low Temperature Multi Effects Desalination-Mechanical Vapor Compression Powered By Supercritical Organic Rankine Cycle, Eydhah Almatrafi

USF Tampa Graduate Theses and Dissertations

Utilizing low grade heat sources such as geothermal, solar or waste heat has received a high attention in recent years. A lot of research has discussed using Organic Rankine Cycle (ORC) as subcritical or supercritical in power generation. However, very few studies extend their research in utilizing ORC in other applications such as desalination. For reverse osmosis (RO) desalination, which is considered a membrane technology, the use of supercritical-ORC in low grade heat sources is more favorable than subcritical-ORC. Thus, studies of utilizing either subcritical-ORC or supercritical-ORC for thermal desalination that use power and heat from Rankine cycle are rare …

Absorber And Window Study – Cdsexte1-X/Cdte Thin Film Solar Cells, Chih-An Hsu

USF Tampa Graduate Theses and Dissertations

CdTe an II-VI semiconductor has been a leading thin film photovoltaic material due to its near ideal bandgap and high absorption coefficient [1]. The typical thin film CdTe solar cells have been of the superstrate configuration with CdS (Eg-2.42eV) as the n-type heterojunction partner. Due to the relatively narrow bandgap of CdS, a wider bandgap n-type window layer has recently emerged as a promising substitute: alloys of MgyZn1-yO have been successfully used as the emitter or window layer. The benefits in the usage of MgyZn1-yO (MZO) are its tunable bandgap and wide optical spectrum on optoelectronic devices. Due to an …

Change Descriptors For Determining Nodule Malignancy In Lung Ct Screening Images, Benjamin Geiger

USF Tampa Graduate Theses and Dissertations

Computed tomography (CT) imagery is an important weapon in the fight against lung cancer; various forms of lung cancer are routinely diagnosed from CT imagery. The growth of the suspect nodule is known to be a prognostic factor in the diagnosis of pulmonary cancer, but the change in other aspects of the nodule, such as its aspect ratio, density, spiculation, or other features usable for machine learning, may also provide prognostic information.

We hypothesized that adding combined feature information from multiple CT image sets separated in time could provide a more accurate determination of nodule malignancy. To this end, we …

High-Precision Lead Isotope Analysis On Modern Populations To Determine Geolocation Reliability, Gennifer M. Goad

USF Tampa Graduate Theses and Dissertations

Forensic anthropologists increasingly use chemical isotope analysis in the investigation of unidentified human remains, as biochemical georeferencing continually improves with the development of modern reference data of known origins. Isotope variations in trace elements such as strontium (Sr) and lead (Pb) in human teeth are some of the most useful indicators of past domicile in archaeological research and thus have high potential for modern, forensic applications. In this study, high-precision lead isotope analysis was conducted on 63 modern human teeth, which were previously analyzed for strontium isotopes. The results present new lead isotope data for the following countries: United States …

Dormancy In The Amphistegina Gibbosa Holobiont: Ecological And Evolutionary Implications For The Foraminifera, Benjamin J. Ross

USF Tampa Graduate Theses and Dissertations

Dormancy, a state of severely decreased or suspended metabolism, is a widespread survival strategy in nature. In the Foraminifera, one of the most studied groups of marine organisms, its presence had been suggested by circumstantial evidence, but rarely studied directly until recently. Despite the lack of research, stressor-induced dormancy can significantly alter the way in which foraminiferal ecology is understood, especially in marginal environments. In this dissertation, I reviewed the evidence for dormancy in the foraminiferal literature, concluding that evidence for dormancy is widespread across the Phylum. I then explored the role of dormancy in the survival of the diatom-bearing …

Improving Strategic It Investment Decisions By Reducing Information Asymmetry, Thomas P. Stablein

USF Tampa Graduate Theses and Dissertations

The unprecedented ubiquity with which technological advancements, such as blockchain, the Internet of things (IoT), big data, machine learning, and artificial intelligence (AI), are impacting the world has forced large organizations to rethink their information technology roadmaps. Their decisions about how they invest in technology have become more important. It is against this backdrop that companies must decide how much to invest in their aging technologies versus these new potentially transformational ones. A decision is only as good as the information available to the decision-makers when they make it. This research project seeks to understand the effects that information asymmetry …

Physical Electronic Properties Of Self-Assembled 2d And 3d Surface Mounted Metal-Organic Frameworks, Radwan Elzein

USF Tampa Graduate Theses and Dissertations

Metal-organic frameworks stand at the frontiers of molecular electronic research because they combine desirable physical properties of organic and inorganic components. They are crystalline porous solids constructed by inorganic nodes coordinated to organic ligands to form 1D, 2D, or 3D structures. They possess unique characteristics such as ultrahigh surface area crystal lattices up to 10000 m² g^-1, and tunable nanoporous sizes ranging from 0.2 to 50 nm. Their unprecedented structural diversity and flexibility beyond solid state materials can lead to unique properties such as tailorable electronic and ionic conductivity which can serve as interesting platforms for a …

Human Body Motions Optimization For Able-Bodied Individuals And Prosthesis Users During Activities Of Daily Living Using A Personalized Robot-Human Model, Dimitrios Menychtas

USF Tampa Graduate Theses and Dissertations

Current clinical practice regarding upper body prosthesis prescription and training is lacking a standarized, quantitative method to evaluate the impact of the prosthetic device. The amputee care team typically uses prior experiences to provide prescription and training customized for each individual. As a result, it is quite challenging to determine the right type and fit of a prosthesis and provide appropriate training to properly utilize it early in the process. It is also very difficult to anticipate expected and undesired compensatory motions due to reduced degrees of freedom of a prosthesis user. In an effort to address this, a tool …

Duty-Cycle Based Physical Unclonable Functions (Pufs) For Hardware Security Applications, Mahmood Javed Azhar

USF Tampa Graduate Theses and Dissertations

Duty cycle and frequency are important characteristics of periodic signals that are exploited to develop a variety of application circuits in IC design. Controlling the duty cycle and frequency provides a method to develop adaptable circuits for a variety of applications. These applications range from stable on-chip clock generation circuits, on-chip voltage regulation circuits, and Physical unclonable functions for hardware security applications. Ring oscillator circuits that are developed with CMOS inverter circuits provide a simple, versatile flexible method to generated periodic signals on an IC chip. A digitally controlled ring oscillator circuit can be adapted to control its duty cycle …

Teacher Attitude And Self-Efficacy Differences Regarding English Language Learners And Disabled Learners., Miriam Carballo

USF Tampa Graduate Theses and Dissertations

There has been little research combining both groups of students who were English Language Learners (ELLs) and Exceptional Student Education (ESE) students in relation to teacher attitudes and self-efficacy. The purpose of this study was to compare teacher attitudes and self-efficacy related to instructing either ELLs with or without disabilities in elementary schools

Teachers from six elementary schools in the XYZ Excellence School District participated in a 52-item comprehensive survey. Two questionnaires and the demographic form were combined to create one comprehensive questionnaire totaling 52 questions for the purposes of this study. Teachers were solicited to participate in the study …

Pursuing Resilience Of Coastal Communities Through Sustainable And Integrated Urban Water Management, Pacia Díaz

USF Tampa Graduate Theses and Dissertations

Reliability of water supply in the urban setting has become essential for communities to function and thrive. It is needed for more than mere human consumption and well-being. Although modern cities have water treatment and distribution systems, pressures from urbanization, population growth and the anticipated pressures of climate change are affecting the quality of water supply and the reliability of treatment and distribution systems. There is therefore an urgent need to take appropriate measures to improve the resilience of water supply systems before the impacts are irreversible.

Improving the resilience of water supply systems can be a challenge. In the …

Numerical Modeling Of Concrete Flow In Drilled Shaft, Jesudoss Asirvatham Jeyaraj

USF Tampa Graduate Theses and Dissertations

Drilled shafts are cylindrical, cast-in-place concrete deep foundation elements. Their construction involves drilled excavation of soil or rock using large diameter augers, and placement of the necessary reinforcing steel in the excavation followed by concreting. Where a high water table is encountered, drilling slurry is used to support the excavation walls and concreting is tremie-placed. Even though the history of drilled shaft construction goes back to the 1950s, the occurrence of anomalies persists in the form of soil inclusions, reduction in shaft cross-sectional area and exposure of reinforcement. One of the main reasons for the anomalies is attributed to the …

The Utility Of The Conductivity Mass-Balance Method For Base Flow Separation In Rivers And Streams, Darline Alegria Lott

USF Tampa Graduate Theses and Dissertations

Freshwater for ecosystems, drinking water, and water for various businesses are important resources and those resources are rapidly diminishing globally due to drought and overuse. In order to manage the availability of water for all concerned, good estimates of base flow (groundwater) is required. Base flow, a component of streamflow, is deduced by separating a stream hydrograph into two components, base flow and runoff. There are several techniques used to perform base flow separation; however two techniques are used in this study, chemical mass-balance and analytical methods. This dissertation explains how an analytical technique was derived from a mass-balance method, …