Digital Commons Network^™

Wireless Physical Layer Design For Confidentiality And Authentication, Tao Wang

USF Tampa Graduate Theses and Dissertations

As various of wireless techniques have been proposed to achieve fast and efficient data communication, it’s becoming increasingly important to protect wireless communications from being undermined by adversaries. A secure and reliable wireless physical layer design is essential and critical to build a solid foundation for upper layer applications. This dissertation present two works that explore the physical layer features to secure wireless communications towards the data confidentiality and user authentication.

The first work builds a reliable wireless communication system to enforce the location restricted service access control. In particular, the work proposes a novel technique named pinpoint waveforming to …

Design Of Variable Wall Thickness Geometry And Performance Mapping Of Scroll Expanders For Distributed Power Generation, Arun Kumar Narasimhan

USF Tampa Graduate Theses and Dissertations

Low-temperature heat sources such as industrial waste heat, solar, and geothermal are more suitable for small-scale power generation rather than utility scale. In order to maximize the electricity generated from low-temperature heat sources, an efficient expansion device for small-scale power output is necessary. This research work has focused on evaluating the use of a scroll expander and improving its geometrical design for the power output range of 1-25 kW_e.

The first part of the work focusses on modeling the performance of a scroll expander using two non-dimensionless parameters, namely, specific speed and specific diameter. Performance of a scroll …

Modeling And Assessing Lava Flow Hazards, Elisabeth Gallant

USF Tampa Graduate Theses and Dissertations

Lava flow hazards are one of the few constant themes across the wide spectrum of volcanic research in the solar system. These dynamic hazards are controlled by the location of the eruption, the topography and material properties of the land upon which the flow spreads, and the properties of the lava (e.g., volume, temperature, and rheology). Understanding the influences on eruption location and how lava flows modify the landscape are important steps to accurately forecast volcanic hazards. Three studies are presented in this dissertation that address di˙erent aspects of modeling and assessing vent opening and lava flow hazards.

The first …

Modulations Of Lipid Membranes Caused By Antimicrobial Agents And Helix 0 Of Endophilin, Nawal Kishore Khadka

USF Tampa Graduate Theses and Dissertations

Understanding the cellular membrane interaction with membrane active biomolecules and antimicrobial agents provides an insight in their working mechanism. Here, we studied the effect of antimicrobial agents; a recently developed peptidomimetics E107-3 and colistin as well as the N-terminal helix H0, of Endophilin A1 on the lipid bilayer.

It is important to discern the interaction mechanism of antimicrobial peptides with lipid membranes in battling multidrug resistant bacterial pathogens. We study the modification of structural and mechanical properties with a recently reported peptidomimetic on lipid bilayer. The compound referred to as E107-3 is synthesized based on the acylated reduced amide scaffold …

Framing Geologic Numeracy For The Purpose Of Geoscience Education: The Geoscience Quantitative Preparation Survey, Victor J. Ricchezza

USF Tampa Graduate Theses and Dissertations

The Geoscience Quantitative Preparation Survey (GQPS) was developed to address a deficiency in the available literature regarding the competency and preparation of early-career geologists in geoscience job-related quantitative skills – namely, geologic numeracy. The final version of the GQPS included self-confidence, usage, satisfaction, and demographic sections. The GQPS was expected to produce data that would allow for an evaluation of the geologic numeracy of early-career geologists and the success of approximately 20 years of increased focus on quantitatively literate geoscience graduates.

The self-confidence section of the GQPS included quantitative methods and quantitative skills. The usage section asked whether participants used …

Tracking Sediment Bypassing, Geomorphological Analysis, And Regional Sediment Management At Tidal Inlets, Tanya M. Beck

USF Tampa Graduate Theses and Dissertations

Tidal inlets on sandy shorelines separate barrier islands and serve as a conduit for transport of sand and water between embayments and oceans, seas, or other tidally influenced waterbodies. Tides and waves induce currents along the coastline that transport sediment across-shore and alongshore. Coastal managers must optimize barrier-inlet system stability while conserving limited sediment resources, and often base management decisions and engineering design upon geomorphic and numerical models that predict the morphological behavior of tidal inlets on short-to-medium timescales (years to decades). The overall goal of this study was threefold. First, to provide science-based practical guidance for regional sediment management …

A Machine Learning Approach To Predicting Community Engagement On Social Media During Disasters, Adel Alshehri

USF Tampa Graduate Theses and Dissertations

The use of social media is expanding significantly and can serve a variety of purposes. Over the last few years, users of social media have played an increasing role in the dissemination of emergency and disaster information. It is becoming more common for affected populations and other stakeholders to turn to Twitter to gather information about a crisis when decisions need to be made, and action is taken. However, social media platforms, especially on Twitter, presents some drawbacks when it comes to gathering information during disasters. These drawbacks include information overload, messages are written in an informal format, the presence …

Iron-Virus Interactions: Development And Testing Of The Ferrojan Horse Hypothesis, Chelsea Bonnain

USF Tampa Graduate Theses and Dissertations

Iron is an essential micronutrient for phytoplankton metabolism that limits growth in many regions of the surface ocean. More than 99.9% of oceanic dissolved iron is organically complexed to an iron-binding ligand, many of which have yet to be characterized. This thesis puts forth the Ferrojan Horse Hypothesis, which predicts a role for marine phages in oceanic iron cycling. Based on evidence from non-marine model systems, the Ferrojan Horse Hypothesis suggests that some marine phages (short for bacteriophages, or viruses that infect bacteria) can use iron as a “Trojan Horse” to gain access to host siderophore-bound iron receptors for infection. …

Reconstruction Of Radar Images By Using Spherical Mean And Regular Radon Transforms, Ozan Pirbudak

USF Tampa Graduate Theses and Dissertations

The goal of this study is the recovery of functions and finite parametric distributions from their spherical means over spheres and designing a general formula or algorithm for the reconstruction of a function f via its spherical mean transform. The theoretical study is and supported with a numerical implementation based on radar data. In this study, we approach the reconstruction problem in two different way. The first one is to show how the reconstruction problem could be converted to a Prony-type system of equations. After solving this Prony-type system of equations, one can extract the parameters that describe the corresponding …

Beyond Labels And Captions: Contextualizing Grounded Semantics For Explainable Visual Interpretation, Sathyanarayanan Narasimhan Aakur

USF Tampa Graduate Theses and Dissertations

One of the long-standing problems in artificial intelligence is the development of intelligent agents with complete visual understanding. Understanding entails recognition of scene attributes such as actors, objects and actions as well as reasoning about the common semantic structure that combines these attributes into a coherent description. While significant milestones have been achieved in the field of computer vision, majority of the work has been concentrated on supervised visual recognition where complex visual representations are learned and a few discrete categories or labels are assigned to these representations. This implies a closed world where the underlying assumption is that all …

A Decision-Making Framework For Hybrid Resource Recovery Oriented Wastewater Systems, Nader Rezaei

USF Tampa Graduate Theses and Dissertations

Water shortage, water contamination, and the emerging challenges in sustainable water resources management (e.g., the likely impacts of climate change and population growth) necessitate adopting a reverse logistics approach, which is the process of moving wastewater from its typical final destination back to the water supply chain for reuse purposes. This practice not only reduces the negative impacts of wastewater on the environment, but also provides an alternative to withdrawal from natural water resources, forming a closed-loop water supply chain. However, the design of such a supply chain requires an appropriate sustainability assessment, which simultaneously accounts for economic, environmental, and …

Sinkhole Lake Infiltration Of Contaminants Of Emerging Concern From Onsite Water Treatment Systems, Ethan A. Upton

USF Tampa Graduate Theses and Dissertations

The advancement in synthetic chemicals commonly referred to as contaminants of emerging concern (CECs) and their application has led to an increase in environmental pollution. The use of septic tanks otherwise referred to as onsite water treatment systems (OWTS), promotes the introduction of CECs into the environment while allowing little in the way of remediation. In order to study the impacts of CECs from OWTS as they infiltrate the environment and the aquifer system, water, sediment, and vegetation samples were collected around a sinkhole lake surrounded by residential housing using OWTSs. The main question of this research project is what …

The Distribution And Biogeochemistry Of Subtropical Intertidal Microbial Mats, Bert D. Anderson

USF Tampa Graduate Theses and Dissertations

Microbial mats have played an important role in the carbon (C) and nutrient cycles since the Archean Eon and modern mats are important contributors to the biogeochemistry of intertidal wetlands. Microbial mats are flat assemblages of microbes that are currently found in many unvegetated habitats globally. Intertidal salt pans are a common habitat for microbial mats, however little is known about the distribution of microbial mats within the intertidal landscape. Understanding the spatial distribution of microbial mats is critical to developing quantitative estimates of the impacts of microbial mats on their ecosystems. We photographically measured the presence and density of …

Habitat Suitability Index Model Of The Florida Sandhill Crane (Grus Canadensis Pratensis) In West-Central Florida, Courtney E. Buck

USF Tampa Graduate Theses and Dissertations

The Florida Sandhill Crane (Grus canadensis pratensis) is a state threatened endemic subspecies of the Sandhill Crane (Nesbitt & Tacha, 1997). With a population that was estimated at a maximum of 5,000 individuals in 2003 (Nesbitt & Hatchitt, 2008), it is imperative to identify potentially viable habitats, as Florida is rapidly developing. This research develops a Habitat Suitability Index model to determine unsuitable to optimally suitable habitat locations throughout west-central Florida. To do so, six suitability variables based on the crane’s life history were evaluated: Potential nesting area, immediate nesting area, wetland coverage, foraging area, brooding area, and road proximity. …

Synthesis, Discovery And Delivery Of Therapeutic Natural Products And Analogs, Zachary P. Shultz

USF Tampa Graduate Theses and Dissertations

Small molecule drug discovery relies heavily on synthetic organic chemistry to develop novel chemical entities that elicit desirable therapeutic effects. The development of targeted chemical syntheses is of paramount importance to access molecules for biological evaluation and is usually considered the bottleneck in most drug discovery campaigns. Targets for chemical syntheses commonly draw inspiration from molecules of natural origin. Nature harbors a wealth of chemical diversity that has established itself over millions of years through chemical and biological evolution. Organisms have an inherent ability to protect themselves from predators and harmful environments. In doing so, many of them evolve to …

Power Graphs Of Quasigroups, Dayvon L. Walker

USF Tampa Graduate Theses and Dissertations

We investigate power graphs of quasigroups. The power graph of a quasigroup takes the elements of the quasigroup as its vertices, and there is an edge from one element to a second distinct element when the second is a left power of the first. We first compute the power graphs of small quasigroups (up to four elements). Next we describe quasigroups whose power graphs are directed paths, directed cycles, in-stars, out-stars, and empty. We do so by specifying partial Cayley tables, which cannot always be completed in small examples. We then consider sinks in the power graph of a quasigroup, …

An Optimal Medium-Strength Regularity Algorithm For 3-Uniform Hypergraphs, John Theado

USF Tampa Graduate Theses and Dissertations

Szemere´di’s Regularity Lemma [32, 33] is an important tool in combinatorics, with numerous appli- cations in combinatorial number theory, discrete geometry, extremal graph theory, and theoretical computer science.

The Regularity Lemma hinges on the following concepts. Let G = (V, E) be a graph and let ∅ /= X, Y ⊂ V be a pair of disjoint vertex subsets. We define the density of the pair (X, Y ) by d_G(X, Y ) = |E[X, Y ]|/(|X||Y |) where E[X, Y ] denotes the …

Rethinking Map Literacy And An Analysis Of Quantitative Map Literacy, Ming Xie

USF Tampa Graduate Theses and Dissertations

Maps are increasingly being used in traditional and virtual media, and civic discourse on political, social, and environmental issues, among others, is more and more becoming influenced by them. The often-used expression of a “picture tells a 1000 words” has never been so apt in our progressively more visual world. Despite this increased role and importance of maps, map literacy, as a field of research, remains rather underdeveloped. This is especially so for thematic maps, the very type of map that is finding increasing currency in discourse. As part of this under-developed nature of map literacy, the quantitative skills used …

Design And Testing Of A Reciprocating Wind Harvester, Ahmet Topcuoglu

USF Tampa Graduate Theses and Dissertations

Renewable energy sources are vital to reduce dependence on fossil fuels that are harmful for the environment and release greenhouse gases causing global warming. Wind energy is a natural source of energy that is abundant in the environment. While wind turbines are most popular, convenient, and used to harvest energy at large scales, there have been recent studies focusing on harvesting energy from the wind for microdevices. Such micro wind energy harvesters can decrease dependence on batteries.

In this study, a novel, framed flag micro wind harvester was designed and tested, and its behavior at three different wind speeds was …

Measuring Influence Across Social Media Platforms: Empirical Analysis Using Symbolic Transfer Entropy, Abhishek Bhattacharjee

USF Tampa Graduate Theses and Dissertations

Social media platforms are interconnected environments that influence each other. Information from one social media platform spreads to another. This thesis proposes a platform-independent framework to analyze information transfer across social media platforms. This thesis uses Symbolic Transfer Entropy and Statistical Significance Test to measure influence and optimize the time window of influence between different platforms. To validate the framework, the thesis analyses the temporal activity dynamics and the information transfer across three different platforms, Reddit, Twitter and GitHub.

Two data driven studies are described in this thesis. The first study finds the optimum time windows of influence between the …

Prioritizing Rehabilitation Of Sanitary Sewers In Pinellas County, Fl, Jesse T. Hillman

USF Tampa Graduate Theses and Dissertations

Following large rain events, extraneous freshwater contributions known as inflow and infiltration (I/I) bypass the storm sewer and enter the sanitary sewer system. In areas with a high water table, like Pinellas County and the surrounding Tampa Bay area, a majority of the wastewater infrastructure is submerged year round exacerbating the rate of groundwater infiltration. This excess flow overloads the existing wastewater infrastructure leading to sanitary sewer overflows (SSOs). These SSOs result in serious problems for municipalities and utilities across the country.

This study was performed in order to assist Pinellas County Utilities in rehabilitating their southern sewer system. To …

Autonomous Monocular Obstacle Detection For Avoidance In Quadrotor Uavs, Panos Valavanis

USF Tampa Graduate Theses and Dissertations

Unmanned Aircraft Systems (UAS) research and development and applications have witnessed unprecedented levels of growth in the past two decades. Although military applications have dominated the market, it is anticipated and expected that civilian and public domain applications will be dominant in the future. Consequently, gradual and timely integration of unmanned aviation into the National Airspace System (NAS) is a real challenge, and roadmaps towards achieving full integration are already in place in the US, Canada, Australia, South Africa and European Union (EU). However, before com- plete integration of manned-unmanned aviation, additional challenging problems need to be addressed and solved, …

Authentication And Sql-Injection Prevention Techniques In Web Applications, Cagri Cetin

USF Tampa Graduate Theses and Dissertations

This dissertation addresses the top two “most critical web-application security risks” by combining two high-level contributions.

The first high-level contribution introduces and evaluates collaborative authentication, or coauthentication, a single-factor technique in which multiple registered devices work together to authenticate a user. Coauthentication provides security benefits similar to those of multi-factor techniques, such as mitigating theft of any one authentication secret, without some of the inconveniences of multi-factor techniques, such as having to enter passwords or biometrics. Coauthentication provides additional security benefits, including: preventing phishing, replay, and man-in-the-middle attacks; basing authentications on high-entropy secrets that can be generated and updated automatically; …

Generalized Derivations Of Ternary Lie Algebras And N-Bihom-Lie Algebras, Amine Ben Abdeljelil

USF Tampa Graduate Theses and Dissertations

We generalize the results of Leger and Luks and other researchers about generalized derivations to the cases of ternary Lie algebras and n-BiHom Lie algebras. We investigate the derivations algebras of ternary Lie algebras induced from Lie algebras, we explore the subalgebra of quasi-derivations and give their properties. Moreover, we give a classification of the derivations algebras for low dimensional ternary Lie algebras.

For the class of n-BiHom Lie algebras, we study the algebras of generalized derivations and prove that the algebra of quasi-derivations can be embedded in the derivation algebra of a larger n-BiHom Lie algebra.

Malicious Manipulation In Service-Oriented Network, Software, And Mobile Systems: Threats And Defenses, Dakun Shen

USF Tampa Graduate Theses and Dissertations

This dissertation includes three approaches we have been designed to tackle threats and challenges in network, software, and mobile security. The first approach demonstrates a new class of content masking attacks against the Adobe PDF standard, causing documents to appear to humans dissimilar to the underlying content extracted by information-based services. The second work protects sensitive data in binaries from being corrupted by cyber attackers. The last work proposes a mechanism which utilizes the unique walking patterns inherent to humans and differentiate our work from other walking behavior studies by using it as first-order authentication and developing matching methods fast …

Probabilistic And Statistical Prediction Models For Alzheimer’S Disease And Statistical Analysis Of Global Warming, Maryam Ibrahim Habadi

USF Tampa Graduate Theses and Dissertations

The importance and applicability of data-driven statistical models have increased significantly. This current study, we have utilized statistical techniques in interdisciplinary research, including environmental and health.

Environmentally, global warming is considered one of the critical issues facing our planet. It is the increase in average global temperatures caused mostly by increases in Carbon Dioxide CO₂. The excessive rise of carbon dioxide from the average level as the side effect of the industrial revolution has a significant impact on blocking the heat and increase the temperature within the Earth’s atmosphere. Based on the record of total CO₂ emissions …

Functional Porous Materials: Applications For Environmental Sustainability, Briana Amaris Aguila

USF Tampa Graduate Theses and Dissertations

Resource depletion, clean water shortages, and global climate change have led to environmental sustainability being of primary concern for both governmental and industrial practices. Current methods to address these challenges typically come as a double-edged sword, fixing one problem while contributing to another. As introduced in chapter one of this dissertation, adsorbent materials are seen as a promising alternative remediation system due to their low energy consumption and minimal chemical waste production. However, many traditional adsorbents, such as activated carbon, metal oxides, and resins, are hindered in practice. This is because they lack the structural tunability to have long-term effectiveness …

Illuminating Changes In Preservice Teachers’ Perceptions About Teaching Elementary Mathematicsin An Introductory Methods Course, Elaine Cerrato

USF Tampa Graduate Theses and Dissertations

Producing highly skilled elementary mathematics teachers capable of facilitating mathematics learning in ways aligned with The Principles and Standards for School Mathematics (NCTM, 2000) and the Common Core State Standards for Mathematics (CCSSM), is a common objective of teacher preparation programs (National Governors Association & Chief Council of State School Officers, 2010). After decades of effort, Brown (2003) argues, teachers continue to teach in the way they were taught; thus, they disregard mathematics standards. As Abell, Appleton, and Hanuscin (2010) note, students’ preexisting ideas relevant to the nature of learning and teaching stem from experiences in their schooling, life, and …

The Potential Of Marine Microbes, Flora And Fauna In Drug Discovery, Santana Alexa Lavonia Thomas

USF Tampa Graduate Theses and Dissertations

Natural products are chemical compounds synthesized by a living organism. These compounds have been utilized by humans from ancient times to the present for their pharmacological and biological activities. Terrestrial organisms are considered a lucrative source of bioactive compounds and chemical diversity. Within the past 60 years, the marine environment has presented its potential as a validated source for structural diversity and biologically active compounds. Technology has given access from shallow waters down to the abyssal plane for exploration and investigation of the inhabitants. Marine organisms have displayed their benefits in the pharmaceutical industry with the approval of several marine-derived …

Phase Evolution And Dynamic Behavior In Materials With Noncollinear Spin Textures, Eleanor M. Clements

USF Tampa Graduate Theses and Dissertations

Noncentrosymmetric magnetic materials have gained special attention due to their ability to stabilize topologically nontrivial magnetic states via the competition between symmetric exchange and the antisymmetric Dzyaloshinskii-Moriya (DM) interaction. The spin struc- tures in these materials have become a center of interest for spintronics applications due to their stable, particle-like properties, and high degree of tunability via control of external parameters, such as magnetic and/or electric field and temperature. Understanding how these robust magnetic structures stabilize, evolve, dynamically respond, and adhere to existing models, all in the presence of external stimuli, are topics of fundamental interest. In this dissertation, the …