Physical Sciences and Mathematics Commons^™

Why Consumers Disclose Their Tourism Experiences On Tourism Social Networking Sites: Multiple Theoretical Perspectives, Junshu Zhang

USF Tampa Graduate Theses and Dissertations

Tourism social networking sites (SNSs) are websites that provide users with templates for describing their travel experiences and an infrastructure to share such travel posts with a network of like-minded individuals. Tourism SNSs represent an important advertising channel for the tourism industry, as they may assist travelers in selecting destinations and planning vacations on the basis of other travelers’ experiences, which may further stimulate travel and generate income for the tourism industry (Yazdanifard & Yee, 2014). User-generated content (UGC) in the form of travel posts is the core offering and key success factor of tourism SNSs. Travel posts constitute a …

Voltage Droop Analysis And Mitigation In Sttram-Based Last Level Cache, Radha Krishna Aluru

USF Tampa Graduate Theses and Dissertations

Preferred especially for a Last Level Cache (LLC) due to its high retention and tolerance capabilities, Spin-Transfer Torque Random Access Memory (STTRAM) is an emerging and a promising Non-Volatile Memory (NVM) technology. To switch the magnetization of a Magnetic Tunnel Junction (MTJ), the amount of current needed is very high (~100μA per bit). For a full cache line (512-bit) write, this extremely high current results in a voltage droop in the conventional cache architecture. Due to this droop, the write operation fails especially when the farthest bank of the cache is accessed. In this thesis, we perform an analysis of …

Scalable Clustering Using The Dempster-Shafer Theory Of Evidence, Alireza Chakeri

USF Tampa Graduate Theses and Dissertations

Clustering large data sets has become very important as the amount of available unlabeled data increases. Single Pass Fuzzy C-Means (SPFCM) is useful when memory is too limited to load the whole data set. The main idea is to divide dataset into several chunks and to apply fuzzy c-means (FCM) to each chunk. SPFCM uses the weighted cluster centers of the previous chunk in the next data chunks. However, when the number of chunks is increased, the algorithm shows sensitivity to the order in which the data is processed. Hence, we improved SPFCM by recognizing boundary and noisy data in …

Asymmetric Transformations Catalyzed By Chiral Binol Alkaline Earth Metal Phosphate Complexes, Sri Krishna Nimmagadda

USF Tampa Graduate Theses and Dissertations

Small molecule hydrogen bond donors have emerged as versatile catalysts in asymmetric synthesis. Within this class, chiral BINOL phosphoric acid is regarded as one of the pioneer catalysts used in several asymmetric transformations. The ability of the catalyst to activate the substrates could be controlled in two different ways. (1) Dual activation/bifunctional activation of substrate by hydrogen bond interactions or ion pairing with phosphoric acid or (2) By forming chiral BINOL phosphate metal complex that could significantly alter the interactions in chiral space. In particular, chiral alkaline earth metal phosphate complexes have unique advantages as catalysts owing to the ubiquitous …

Pedestrian Detection In Low Quality Moving Camera Videos, Saurabh Hinduja

USF Tampa Graduate Theses and Dissertations

Pedestrian detection is one of the most researched areas in computer vision and is rapidly gaining importance with the emergence of autonomous vehicles and steering assistance technology. Much work has been done in this field, ranging from the collection of extensive datasets to benchmarking of new technologies, but all the research depends on high-quality hardware such as high-resolution cameras, Light Detection and Ranging (LIDAR) and radar.

For detection in low-quality moving camera videos, we use image deblurring techniques to reconstruct image frames and use existing pedestrian detection algorithms and compare our results with the leading research done in this area.

Lava Flow Hazard Assessment For The Idaho National Laboratory, Idaho Falls, And Pocatello, Idaho, U.S.A., Elisabeth Gallant

USF Tampa Graduate Theses and Dissertations

This study presents a probabilistic lava flow hazard assessment for the Idaho National Laboratory (INL) and the cities of Idaho Falls and Pocatello, Idaho. The impetus of this work is to estimate the conditional probability that a lava flow on the eastern Snake River Plain (ESRP) will impact the areas of interest given the formation of a new volcanic vent in the region. A list of 288 eruptive events, derived from a previously published inventory of 506 surface and 32 buried vents, was created to reduce the biasing of spatial density maps towards eruptions with multiple dependent vents. Conditional probabilities …

The Role Of Partial Surface Charge Compensation In The Properties Of Ferroelectric And Antiferroelectric Thin Films, Elena Glazkova

USF Tampa Graduate Theses and Dissertations

Ferroelectric and antiferroelectric ultrathin films have attracted a lot of attention recently due to their remarkable properties and their potential to allow for device miniaturization in numerous applications. However, when the ferroelectric films are scaled down, it brings about an unavoidable depolarizing field. A partial surface charge compensation allows to control the residual depolarizing field and manipulate the properties of ultrathin ferroelectric films. In this dissertation we take advantage of atomistic first-principles-based simulations to expand our understanding of the role of the partial surface charge compensation in the properties of ferroelectric and antiferroelectric ultrathin films.

The application of our computational …

Design And Development Of Peptidomimetic Ligands For Targeting Radiopharmaceuticals, Imaging Probes, And Immunotherapeutics In Oncologic Disease, Michael Lawrence Doligalski

USF Tampa Graduate Theses and Dissertations

Cancer is a leading cause of morbidity and mortality in the developed world. While much has been learned about these diseases in the last few decades, one of the main barriers to widespread advancement is the heterogeneity of cancer biology. A growing body of evidence supports the idea that certain protein receptors are overexpressed on the surface of tumor cells as compared to normal tissues. These extracellular biomarkers provide a unique opportunity to selectively target the tumor with both imaging and therapeutic modalities. The research in this dissertation focuses on targeting proteins on the tumor cell surface with peptidomimetic ligands. …

Parallelization Of Push-Based System For Molecular Simulation Data Analysis With Gpu, Iliiazbek Akhmedov

USF Tampa Graduate Theses and Dissertations

Modern simulation systems generate big amount of data, which consequently has to be analyzed in a timely fashion. Traditional database management systems follow principle of pulling the needed data, processing it, and then returning the results. This approach is then optimized by means of caching, storing in different structures, or doing some sacrifices on precision of the results to make it faster. When it comes to the point of doing various queries that require analysis of the whole data, this design has the following disadvantages: considerable overhead on traditional disk random I/O framework while reading from the simulation output files …

Abundance Of Archaias Angulatus On The West Florida Coast Indicates The Influence Of Carbonate Alkalinity Over Salinity, Sean Thomas Beckwith

USF Tampa Graduate Theses and Dissertations

Archaias angulatus, a large symbiont-bearing foraminifer (Order Miliolida) that produces a Mg-calcite shell, is common throughout the Caribbean and warm western Atlantic region. This species lives abundantly in seagrass beds along the Springs Coast of northwest Florida (up to 4 adults per gram of sediment) where spring-fed rivers emerge from a limestone aquifer, and in Florida Bay to the southeast (25 adults/g) where the sediment is primarily biogenic carbonate. In contrast, live specimens are seldom found in the seagrass beds along the central-west coast of Florida, where barrier islands are dominated by quartz sand. My working hypothesis is that substratum …

Effect Of Void Fraction On Transverse Shear Modulus Of Advanced Unidirectional Composites, Jui-He Tai

USF Tampa Graduate Theses and Dissertations

In composite materials, transverse shear modulus is a critical moduli parameter for designing complex composite structures. For dependable mathematical modeling of mechanical behavior of composite materials, an accurate estimate of the moduli parameters is critically important as opposed to estimates of strength parameters where underestimation may lead to a non-optimal design but still would give one a safe one.

Although there are mechanical and empirical models available to find transverse shear modulus, they are based on many assumptions. In this work, the model is based on a three-dimensional elastic finite element analysis with multiple cells. To find the shear modulus, …

The Geophysical Kitchen Sink Approach To Improving Our Understanding Of Volcano-Tectonic Interactions, Ophelia Ann George

USF Tampa Graduate Theses and Dissertations

A multi-prong approach was taken in this dissertation to understand volcanic processes from both a long-term and more immediate hazard perspective. In the long-term, magma sources within the crust may produce measurable surficial response and long-wavelength gravity anomalies that provide information about the extent and depth of this magma. Long-term volcanic hazard forecasting is also improved by developing as complete a record as possible of past events. In the short-term, a long-standing question has been on the casting of precursory volcanic activity in terms of future volcanic hazards. Three studies are presented in this dissertation to address these issues. Inversion …

Efficient Algorithms And Applications In Topological Data Analysis, Junyi Tu

USF Tampa Graduate Theses and Dissertations

Topological Data Analysis (TDA) is a new and fast growing research field developed over last two decades. TDA finds many applications in computer vision, computer graphics, scientific visualization, molecular biology, and material science, to name a few. In this dissertation, we make algorithmic and application contributions to three data structures in TDA: contour trees, Reeb graphs, and Mapper. From the algorithmic perspective, we design a parallel algorithm for contour tree construction and implement it in OpenCL. We also design and implement critical point pairing algorithms to compute persistence diagrams directly from contour trees, Reeb graphs, and Mapper. In terms of …

A Molluscan Record Of Monsoonal Precipitation Along The Western Shoreline Of The Late Maastrichtian Western Interior Seaway, Scott Allen Ishler

USF Tampa Graduate Theses and Dissertations

Global warming in response to increasing levels of atmospheric CO2 concentration (pCO₂) has generated concern over the effects of increasing surface temperature on the hydrologic cycle. Investigating precipitation dynamics during past ‘greenhouse’ intervals provide important insights necessary to better constrain potential future climate scenarios. The Late Cretaceous greenhouse is characterized by elevated pCO₂ and surface temperatures, with a prolonged cooling trend which initiated in the late Campanian and an associated 4^th-order sea-level regression recorded in the Western Interior Seaway (WIS), providing an opportunity to examine the hydrologic cycle under conditions of changing temperature and sea-level. …

Material Expertise: Applying Object-Oriented Rhetoric In Marine Policy, Zachary Parke Dixon

USF Tampa Graduate Theses and Dissertations

This dissertation applies object-oriented rhetorics and posthuman philosophies to environmental policy deliberation in order to help bridge gaps between policy makers, scientists, and citizens. For environmental policy scholars the non-credentialed expertise of local, or indigenous stakeholders is valued as possessing technical, objective merit that can improve the development and implementation of environmental policies. However, the utilization of stakeholder expertise in environmental policy faces serious challenges in terms of finding common grounds for communication within complex techno-social systems, of overcoming deep cultural differences and perceptions, and grave ethical issues of access and power. This dissertation develops two case studies of marine …

Monitoring And Mitigation Of Elevated Co2 Impacts Using Microalgae, Terry-Rene Wiesner Brown

USF Tampa Graduate Theses and Dissertations

Climate change is arguably the greatest environmental and economic challenge of our time. There are considerable documented and projected impacts to both human and natural systems as a result of climate change. These impacts include changes in temperature, sea level, precipitation patterns, and biogeography of ecologically and economically relevant species, including pathogens. One of the main drivers of climate change is elevated levels of atmospheric carbon dioxide (CO₂), a greenhouse gas. Since pre-industrial times, atmospheric CO₂ levels have increased from approximately 280 ppm to over 400 ppm, as a result of fossil fuel combustion, cement production and …

Photic Stress In Symbiont-Bearing Reef Organisms: Analyses Of Photosynthetic Performance, Natasha Mendez-Ferrer

USF Tampa Graduate Theses and Dissertations

Photo-oxidative stress is one of the key factors that can induce bleaching in reef organisms. With the decline of coral reefs and recurrent bleaching events, many studies have focused on understanding the mechanism behind this phenomenon. Two of the hypotheses that explain how the photosynthetic performance of the symbiont is affected and influences bleaching are: (1) disruption of the photosynthetic pathway by direct damage to the photosystem II (PSII), and (2) by inhibition of the Calvin-Benson cycle. In this dissertation I examine different aspects of photosynthetic performance in symbiont-bearing reef organisms and how this is influenced by symbiont loss and …

A Smartphone-Based System For Clinical Gait Assessment, Andres Alfredo Perez Leon

USF Tampa Graduate Theses and Dissertations

Patients with lower limbs problems are an increasing population in the US and many of them require surgery and its subsequent post-op Physical Therapy (PT). For all these patients, tracking their progress and evolution towards full recovery is very important. To assess the patients and track their progress, patients are usually required to perform very specific tests administered by a physical therapist. These tests either require very expensive equipment or rather require the subjective experience of the physical therapist who administer them. One of these tests is the Functional Gait Assessment (FGA) test, perhaps the most widely adopted one for …

Authentication In Wireless Body Area Networks (Wban), Nagalaxmi Yenuganti

USF Tampa Graduate Theses and Dissertations

With the advancements in technology and computing environment capabilities, the number of devices that people carry has increased exponentially. This increase initially occurred as a result of necessity to monitor the human body condition due to chronic diseases, heart problems etc. Later, individuals’ interest was drawn towards self-monitoring their physiology and health care. This is achieved by implanting various sensors that can proactively monitor the human body based on medical necessity and the health condition of the user. Sensors connected on a human body perceive phenomena such as locomotion or heartbeat, and act accordingly to form a Body Area Network. …

Polymer Characteristics Of Polyelectrolyte Polypeptides, Jorge Monreal

USF Tampa Graduate Theses and Dissertations

Polypeptides are polymerized chains of amino acids linked covalently through peptide bonds. Polyelectrolyte polypeptides are polypeptides with electrolyte repeating groups. Several amino acids contain ionizable side chains which result in charge distributions when dissolved in aqueous solutions. This dissertation is motivated by a desire to gain knowledge of polyelectrolyte polypeptides as recent advances in chemical synthesis of polypeptides have made possible the fabrication of designed polypeptides that do not naturally occur in nature. Potential applications of newly designed polypeptides span the range from medical to clothing and energy even to robotics.

In this dissertation we compare the characteristic behavior of …

Applications Of Molecular Modelling And Structure Based Drug Design In Drug Discovery, Sreya Mukherjee

USF Tampa Graduate Theses and Dissertations

Calcium ions have important roles in cellular processes including intracellular signaling, protein folding, enzyme activation and initiation of programmed cell death. Cells maintain low levels of calcium in their cytosol in order to regulate these processes. When activation of calcium-dependent processes is needed, cells can release calcium stored in the endoplasmic reticulum (ER) into the cytosol to initiate the processes. This can also initiate formation of plasma membrane channels that allow entry of additional calcium from the extracellular milieu. The change in calcium levels is referred to as calcium flux. A key protein involved in initiation of calcium flux is …

The Effect Of Home Range Estimation Techniques On Habitat Use Analysis, Brendon Quinton

USF Tampa Graduate Theses and Dissertations

The term “home range” refers to the area in which an animal spends most of its time during everyday activities. This study examined the effects of four different home range estimation techniques on the proportions of habitats located therein. The study utilized a point dataset collected for twenty individual Florida Black Bears (Ursus americanus floridanus), occurring in five different areas throughout the state of Florida. Each dataset was used to create home ranges using the following techniques: (1) Minimum Convex Polygon, (2) Kernel Density Estimation, (3) Characteristic Hull Polygon, and (4) Time-Geographic Density Estimation, a new home range …

Fast Computation On Processing Data Warehousing Queries On Gpu Devices, Sam Cyrus

USF Tampa Graduate Theses and Dissertations

Current database management systems use Graphic Processing Units (GPUs) as dedicated accelerators to process each individual query, which results in underutilization of GPU. When a single query data warehousing workload was run on an open source GPU query engine, the utilization of main GPU resources was found to be less than 25%. The low utilization then leads to low system throughput. To resolve this problem, this paper suggests a way to transfer all of the desired data into the global memory of GPU and keep it until all queries are executed as one batch. The PCIe transfer time from CPU …

Enforcing Security Policies On Gpu Computing Through The Use Of Aspect-Oriented Programming Techniques, Bader Albassam

USF Tampa Graduate Theses and Dissertations

This thesis presents a new security policy enforcer designed for securing parallel computation on CUDA GPUs. We show how the very features that make a GPGPU desirable have already been utilized in existing exploits, fortifying the need for security protections on a GPGPU. An aspect weaver was designed for CUDA with the goal of utilizing aspect-oriented programming for security policy enforcement. Empirical testing verified the ability of our aspect weaver to enforce various policies. Furthermore, a performance analysis was performed to demonstrate that using this policy enforcer provides no significant performance impact over manual insertion of policy code. Finally, future …

Electrospinning Of Polymeric Solutions Using Opuntia Ficus-Indica Mucilage And Iron Oxide For Nanofiber Membranes For Treating Arsenic Contaminated Water, Venkatesh Eppili

USF Tampa Graduate Theses and Dissertations

Water is the essential part of every organism and it is also a vital constituent of healthy living and diet. Unfortunately water contamination over the past decade has increased dramatically leading to various diseases. As technology advances, we are detecting many pollutants at smaller levels of concentrations. Arsenic (As) is one of those major pollutants, and Arsenic poisoning is a condition caused due to excess levels of arsenic in the body. The main basis for Arsenic poisoning is from ground water which naturally contains high concentrations of arsenic. A case study from 2007 states that over 137 million people in …

Oversampling Methods For Imbalanced Dataset Classification And Their Application To Gynecological Disorder Diagnosis, Iman Nekooeimehr

USF Tampa Graduate Theses and Dissertations

In many applications, the dataset for classification may be highly imbalanced where most of the instances in the training set may belong to some of the classes (majority classes), while only a few instances are from the other classes (minority classes). Conventional classifiers will strongly favor the majority class and ignore the minority instances. The imbalance problem can occur in both binary data classification and also in ordinal regression. Ordinal regression is a supervised approach for learning the ordinal relationship between classes. Extensive research has been performed for addressing imbalanced datasets for binary classification; however, current methods do not address …

Impact Of Visualization On Engineers – A Survey, Dhaval Kashyap Shah

USF Tampa Graduate Theses and Dissertations

In the recent years, there has been a tremendous growth in data. Numerous research and technologies have been proposed and developed in the field of Visualization to cope with the associated data analytics. Despite these new technologies, the pace of people’s capacity to perform data analysis has not kept pace with the requirement. Past literature has hinted as to various reasons behind this disparity. The purpose of this research is to demonstrate specifically the usage of Visualization in the field of engineering. We conducted the research with the help of a survey identifying the places where Visualization educational shortcomings may …

Digital Integration, Jacob C. Boccio

USF Tampa Graduate Theses and Dissertations

Artificial intelligence is an emerging technology; something far beyond smartphones, cloud integration, or surgical microchip implantation. Utilizing the work of Ray Kurzweil, Nick Bostrom, and Steven Shaviro, this thesis investigates technology and artificial intelligence through the lens of the cinema. It does this by mapping contemporary concepts and the imagined worlds in film as an intersection of reality and fiction that examines issues of individual identity and alienation. I look at a non-linear timeline of films involving machine advancement, machine intelligence, and stages of post-human development; Elysium (2013) and Surrogates (2009) are about technology as an extension of the self, …

Decision Support Systems For Water Management: Investigating Stakeholder Perceptions Of System Use, Gabriella Balsam

USF Tampa Graduate Theses and Dissertations

Water resources are becoming increasingly important to protect, but doing so has proven challenging due to the complex nature of resource management. Many researchers have been trying to develop “usable science” to aid in this endeavor, and one method of this is the development of decision support systems. This has led to the employment of this method as a potential tool for decision makers, scientists, and the interested public to use; yet little literature is available on the success of their implementation. This study attempted to fill the gaps by gathering data through surveys and interviews from stakeholders who are …

Impact Of Sludge Layer Geometry On The Hydraulic Performance Of A Waste Stabilization Pond, Faissal Romaric Ouedraogo

USF Tampa Graduate Theses and Dissertations

Improving the hydraulic performance of waste stabilization ponds (WSPs) is an important management strategy to not only ensure protection of public health and the environment, but also to maximize the potential reuse of valuable resources found in the treated effluent. To reuse effluent from WSPs, a better understanding of the factors that impact the hydraulic performance of the system is needed. One major factor determining the hydraulic performance of a WSP is sludge accumulation, which alters the volume of the pond.

In this study, computational fluid dynamics (CFD) analysis was applied to investigate the impact of sludge layer geometry on …