Digital Commons Network^™

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 …

International Teaching Assistants’ Perceptions Of English And Spanish Language Use At The University Of Puerto Rico-Mayagüez, Edward G. Contreras Santiago

USF Tampa Graduate Theses and Dissertations

Globalization and sociopolitical factors impact migration patterns all over the world. In Puerto Rico, these factors created superdiverse environments where languages users have pushed the boundaries of language in order to make sense of their worlds. Even though this language dynamic is natural for locals, it is those who visit from different countries, specifically international graduate students, that have a difficult time adjusting to Puerto Rico’s rich use of English and Spanish. Understanding how international graduate students perceive the language used at the University of Puerto Rico, Mayagüez (UPRM) upon arrival is essential to provide a better experience for future …

Rf Power Circuit Designs For Wi-Fi Applications, Krishna Manasa Gollapudi

USF Tampa Graduate Theses and Dissertations

In the field of RF/Microwave Engineering, the Wilkinson Power divider is a passive device frequently used for splitting or combining signals. The power fed to the input port is equally or unequally split between N output ports and delivers better performance by achieving isolation between the output ports while matching all the ports. The design comprises simple transmission lines and provides power divider characteristics with the help of quarter wavelength transmission lines with different topologies.

This thesis describes the design and fabrication of lumped and N way power splitter working at an operating frequency of 2.4 GHz. These circuits are …

The Design Of Passive Networks With Full-Wave Component Models, Eric Valentino

USF Tampa Graduate Theses and Dissertations

In this thesis, the design of passive networks with the aid of full-wave simulation software and geometry-based models of lumped elements is investigated. This is done by examining the results of a number of simulation examples, as well as measured data from manufactured designs to compare against simulated equivalents. One such example is a chip antenna evaluation board design, in which the PCB, antenna, matching components and connector are all modeled. When measured, the simulation agreed with the board’s best matched frequency of 5.5 GHz to within 20 MHz. In another, a new antenna layout is generated from an existing …

To Compare Cyclosporine A Nanoformulations For Their Effectiveness In Reducing Nephrotoxicity, Ilkin Nasirli

USF Tampa Graduate Theses and Dissertations

Cyclosporine (CsA) is one of the main immune-suppressant agents which has been used widely in organ transplantation against graft rejection. However, the low oral bioavailability and the associated adverse effects such as nephrotoxicity are the main drawbacks of current usage of this drug. Thus, purpose of this research is to formulate PLGA nanoparticles of CsA to improve its effectiveness and to reduce the nephrotoxicity induced by the plain drug. CsA-loaded PLGA nanoparticles were prepared by the nanoprecipitation method. Particle size and zeta potential of the formulation was determined and percent drug entrapment were also determined. Quantitative estimation was carried out …

The Relationship Between Hand And Wrist Musculoskeletal Disorders And Hand Activity And Posture, Warren M. Henry

USF Tampa Graduate Theses and Dissertations

Musculoskeletal disorders are common in many industries such as automotive, manufacturing and line assembly. Risk factors include high frequency or hand repetition, long duration of work activities with short rest periods, unsustainable postures which put strain on the body and muscles, and activities that require significant force to fulfill duties. The current ACGIH TLV for hand activity uses hand activity level (HAL) and normalized peak force (NPF) to assess an individual’s risk of developing an MSD. The purpose of this study is to propose the use of Posture as an alternative to NPF and couple it with HAL to assess …

Collaboration: Who, When, And Why To Work Together, Michelle S. Kaplan

USF Tampa Graduate Theses and Dissertations

This study looked at how individuals choose whom to work with when a task necessitates collaboration. Prior research done on collaborative environments as well as outcomes of collaboration suggests that who you collaborate with will depend on two primary factors: the individuals from which you have to choose and the circumstances surrounding the task. In the proposed study, these factors will be explored. This thesis identified the lack of literature on informal collaboration, addressing the gap in the literature regarding processes that individuals use when choosing collaborators. This research focused on the influencing factors of similarity and expertise involved in …

Responsive Coatings And Functional Systems From Pectin Polysaccharides, Zeinab Veisi

USF Tampa Graduate Theses and Dissertations

Pectin polysaccharides provide promising potential as all-natural, non-toxic “green” coatings. Pectin polysaccharides have been drawing growing attention as elements of stimuli-responsive systems and as source materials for functionalized robust coatings. They can be extracted from several natural sources and are intrinsically biocompatible. The majority of the applications of pectin gels require a better understanding of the properties of thin layers of gels at surfaces and interfaces. Despite the prevalence of bulk gels of pectin, coatings of pectin have not been reported. In bulk hydrogels, swelling of polymer networks is controlled by a diffusion limited transport process in which the rate …

Pazopanib Loaded Plga Nanoparticles For The Treatment Of Age-Related Macular Degeneration, Gulimirerouzi Fnu

USF Tampa Graduate Theses and Dissertations

Age-related macular degeneration (AMD) is a reason of severe vision loss worldwide. Pazopanib is a multitargeted tyrosine kinase inhibitor drug that can reduce neovascularization by mainly acting on vascular endothelial growth factor receptor (VEGFR). An intraocular injection to posterior segment of eye of anti-VEGF agent at present represents the cornerstone of therapies for AMD. However, challenges in targeting and delivering drug to eye’s posterior segment well as difficulties arising from repetitive frequent intraocular injections, which requires novel drug delivery method. In this study, pazopanib loaded PLGA‐NPs were prepared and the studied formulation had particle size of 132.1 ± 1.4 nm …

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 …

Carbon Dioxide Adsorption Using Solid Amine Sorbents, Umadevi Gopalakrishnan

USF Tampa Graduate Theses and Dissertations

Biogas, being rich in methane, can be used as a fuel for various end uses such as electricity generation, compressed natural gas (CNG), production of liquid fuels, industrial heating, etc. CO₂ is the major contaminant in biogas (30–50%) along with other impurities such as NH₃, H₂S, and water. CO₂ in the biogas decreases the heating value of biogas. Natural gas pipelines and vehicle use require high purity (> 95%) CH₄. There are many commercial techniques available for CO₂ removal from biogas such as such water scrubbing (WS), chemical scrubbing (CS) using …

Improving Stability By Enhancing Critical Fault Clearing Time, Ammara M. Ghani

USF Tampa Graduate Theses and Dissertations

The Bulk Electric System (BES) in the United States includes transmission lines of 100kV and above, transformers of 100kV and above on Low Voltage (LV) side and generating units that step up to 100 kV and above. The BES is a power network that connects different states and utility companies via tie lines for exchange of Power.

To maintain the integrity of power systems, it is very important to keep the BES intact and for that the regulatory authority, North American Electric Reliability Corporation (NERC), has developed over 100s of reliability standards and is responsible to enforce them.

During the …

Effect Of Promoter (Mn) On The Performance Of Sba-15 Supported Iron Catalysts For High Temperature Fischer-Tropsch Synthesis, Sreya Mariya Seby

USF Tampa Graduate Theses and Dissertations

Development of an effective High Temperature Fischer-Tropsch Synthesis (HTFTS) catalyst is of interest in process intensification that combines methane reforming with long chain hydrocarbon production. Literature indicates iron catalysts supported on mesoporous silica performed relatively well in high temperature applications. In this work, we investigated the effect of manganese promoter on iron catalysts for FTS at 430 °C as it was known from previous studies that manganese promotion could enhance the CO conversion with higher hydrocarbon yields. Also, the effect of temperature on FTS activity was evaluated by testing the base and promoted Fe/SBA-15 catalysts for temperature ranging from 370 …

Encapsulation Of Organic Thermochromic Materials With Silicon Dioxide, Mingyang Huang

USF Tampa Graduate Theses and Dissertations

Currently, functional materials are attracting considerable attention in the effort to solve some tough challenges the world is faced with. Thermochromic (TC) materials have the potential to make buildings more energy efficient because of their ability to change color (i.e black to white) at specific temperatures. Using this property, TC materials can reflect solar radiation in the summer, to keep a building cool during daytime hours, and absorb solar radiation in the winter to keep the building warm when their color is dark. Very often, to increase their durability, thermochromic materials are encapsulated. In this work, a new process has …

On Distributed Control Of Multiagent Systems Under Adverse Conditions, Emre Yildirim

USF Tampa Graduate Theses and Dissertations

The objective of this thesis is (1) to show the experimental validation of recently proposed distributed adaptive control architecture for a class of heterogeneous uncertain multiagent systems as well as (2) to theoretically propose a proportional integral controller for multiagent systems having limited resources in the presence of a disturbance with stability analyses.

With regard to (1), the distributed adaptive control architecture used in the experiment utilizes a control input having a nominal part and an adaptive augmentation part for each agent to suppress the effect of uncertainties and disturbances effectively. This architecture is capable to provide uniform ultimate boundedness …

Morphology And Detection Of Corrosion On Stainless Steel Reinforcement In Concrete, Julio J. Saire Yanez

USF Tampa Graduate Theses and Dissertations

Stainless steel (SS) has emerged as an alternative corrosion-resistant reinforcement in concrete instead of the commonly used carbon steel (CS). The biggest advantage of SS is that it takes more time for corrosion to initiate than for CS. An additional benefit from the use of SS in concrete may be derived from the period after the corrosion started until the concrete structure reaches a limit state. This period is called corrosion propagation stage (CPS) and it has been hardly studied in SS reinforced structures. The duration of this period could be related, among other factors, to the morphology of corrosion …

Sorption Of Benzene, Tolueneand Ethylbenzeneby Plasticized Pema And Pema/Pmma Sensing Films Using Aquartz Crystal Microbalance (Qcm) At 298.15k, Deekshitha Adapa

USF Tampa Graduate Theses and Dissertations

Detection of volatile organic compounds (VOC’s) in the environment is important for human health and wellness. Long term exposure of certain VOC’s like benzene, toluene, ethylbenzene and xylene (BTEX) has a severe effect on human health. There are techniques such as gas chromatography, photo ionization, and mass spectroscopy that are time consuming, require gas sampling and are ineffective in real time sensing in air. Acoustic wave devices such as surface acoustic wave (SAW) devices can be used for sensing BTEX compounds in both vapor and liquid phase. The quartz crystal microbalance (QCM) is a low-frequency acoustic wave device, which can …

An Examination Of The Roles Of Classroom Quality And Approaches To Learning On The Early Academic Skills Of Latino Dual Language Learners Enrolled In Head Start, Marcela A. Galicia

USF Tampa Graduate Theses and Dissertations

This thesis examined the relationship between classroom quality, approaches-to-learning, and early academic skills among 384 Latino dual language learners (DLLs) enrolled in Florida Head Start programs. The children were living in low-income homes where Spanish was the primary language spoken by at least one parent. The study analyzed the extent to which approaches-to-learning behaviors moderate early literacy and numeracy skills in Head Start classrooms of varying quality. During the spring of their prek-4 year, the children were administered the English and Spanish Letter-Word Identification and Applied Problems subtests of the WJ-III (Woodcock, McGrew, & Mather, 2001) and the Batería III …

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 …

Cubesat Constellation Design For Intersatellite Linking, Michael T. White

USF Tampa Graduate Theses and Dissertations

This thesis investigates the concept of controlling a CubeSat constellation in low-Earth orbit. Low-Earth orbits are considered because the torque used for satellite control is supplied with magnetorquers, and the closer the satellite is to Earth’s magnetic field the more control gain can be supplied. Also, this is the expected orbit altitude of future CubeSat constellations to enable communications.

Controlling a CubeSat relies on attitude determination. This means being able to estimate its attitude relative to a given reference frame. To determine the attitude, we propose to use a star tracker and a Kalman filter. A star tracker scans the …

Quantifying The Friedreich Ataxia Rating Scale And The Functional Performance Measures, Chelsea Rene Davis

USF Tampa Graduate Theses and Dissertations

Friedreich Ataxia (FA) is a debilitating autosomal-recessive neurodegenerative disorder which is characterized by ataxia of all four limbs, difficulty walking, areflexia, and dysarthria. Further complications of FA include diabetes, scoliosis, and hypertrophic cardiomyopathy. Approximately three-quarters of people with FA have onset before the age of 25 and in most instances, affected individuals will require the use of a wheelchair within ten years after symptoms emerge.

The current advancements in clinical trials have escalated the developmental demand for a scale which validates adjustments in FA. The Friedreich Ataxia Rating Scale (FARS) is a disease-specific semi-qualitative assessment which includes three subscales (functional …

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 …

Design And Testing Of Experimental Langmuir Turbulence Facilities, Zongze Li

USF Tampa Graduate Theses and Dissertations

Langmuir Circulation is a common phenomenon driven by wind in oceans and lakes and was first studied by Langmuir in 1927. According to various ocean observations, this kind of phenomenon plays an important role in many phenomena such as the aggregation of bubbles, the distribution of plankton as well as the mixing of spilled oil and sediment in the ocean. To study this, an experimental facility has been developed in the lab which creates a small scale version of Langmuir Circulation.

This thesis is about the design and testing of this tank and surrounding aluminum frame, as well as the …

Statistical Anomaly Detection And Mitigation Of Cyber Attacks For Intelligent Transportation Systems, Ammar Haydari

USF Tampa Graduate Theses and Dissertations

Secure vehicular communication is a critical factor for secure traffic management. Perfect security in intelligent transportation systems (ITS) has solid and efficient intrusion detection systems (IDS). In this paper, we consider false data injection attacks and distributed denial-ofservice attacks (DDoS), especially the stealth low-rate DDoS attacks, targeting the integrity and availability, respectively, in vehicular ad-hoc networks (VANET). Novel statistical intrusion detection and mitigation techniques are proposed for the considered attacks. The performance of the proposed methods are evaluated using a traffic simulator and a real traffic dataset. Comparisons with the state-of-the-art solutions clearly demonstrate the superior performance of the proposed …

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, …

Density-Mediated Interactions Are Stronger But More Variable Than Trait-Mediated Interactions In Predator–Prey Systems, Travis M. Flock

USF Tampa Graduate Theses and Dissertations

Theoretical and empirical considerations of predator-prey dynamics have sought to determine the dominant of two effects exerted by predators onto prey: consumptive effects of predators and non-consumptive, or trait-mediated, effects. Many studies have identified trait-mediated interactions (TMIs) in diverse taxa, and meta-analyses of these studies found that prey population dynamics are as strongly – if not more strongly – affected by TMIs as density-mediated interactions (DMIs). Since then, there is now an expanded primary literature, and given this potential for new insight on the direct and indirect effect of predators on prey, the cost of traits involved in TMIs relative …

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; …