Digital Commons Network^™

Hurricane Forecasting, Warning And Response Systems: A Lake Wales Public Perception Study, April E. Raulerson

USF Tampa Graduate Theses and Dissertations

This research investigates the public perception of hurricane forecasting and warning systems with a view to improving response activities. The hazard literature shows that the effectiveness of such systems is contingent upon on the smooth operation of all components of the system and that warning recipients fully understand the implications of the warning message by taking appropriate action. It is argued that public perception of warning systems will vary depending on various socio-demographic factors, such as age, gender, level of education, socioeconomic status and area, factors that will ultimately influence overall effectiveness. To test this, a questionnaire survey was undertaken …

Making Sense Of Complex System Failure: The Case Of 9/11, Sandra M. Cooper

USF Tampa Graduate Theses and Dissertations

The National Commission on Terrorist Attacks attributed the September 11 attacks on the U.S. homeland to the terrorists' exploitation of "deep institutional failings." These findings are similar to the conclusions of the Presidential Commission investigating the 1986 Challenger accident and the Columbia Accident Investigative Board (2003). Generally Commissions aim to provide the fullest possible account of events contributing to the catastrophe under investigation and to identify lessons learned, but avoid specifying responsibility and accountability. For this reason, various commission reports have been criticized for being abstract and shallow. These criticisms make a valid point. How commissions make sense of failures …

The Role Of Computer-Mediated Communication In Non-Native Speakers’ Acquisition Of Academic Literacy, Rui Cheng

USF Tampa Graduate Theses and Dissertations

Research shows that academic literacy is discipline specific. Students have to learning the ways of communication in order to gain access to the discourse community of the selected discipline through understanding and performing required genres and learning necessary disciplinary knowledge. Scaffolding is important in the process to help students internalize the disciplinary knowledge and improve students' performance on academic papers. Computer-mediated communication (CMC) provides good chances of scaffolding and mediation especially for non-native graduate students who may have lost many opportunities of class participation due to their limited language proficiency or other cultural issues.

In this dissertation, the researcher investigated …

Maximizing Manipulation Capabilities Of Persons With Disabilities Using A Smart 9-Degree-Of-Freedom Wheelchair-Mounted Robotic Arm System, Redwan M. Alqasemi

USF Tampa Graduate Theses and Dissertations

Physical and cognitive disabilities make it difficult or impossible to perform simple personal or job-related tasks. The primary objective of this research and development effort is to assist persons with physical disabilities to perform activities of daily living (ADL) using a smart 9-degrees-of-freedom (DOF) modular wheelchair-mounted robotic arm system (WMRA).

The combination of the wheelchair's 2-DoF mobility control and the robotic arm's 7-DoF manipulation control in a single control mechanism allows people with disabilities to do many activities of daily living (ADL) tasks that are otherwise hard or impossible to accomplish. Different optimization methods for redundancy resolution are explored and …

Academic Capitalism In The Social Sciences: Faculty Responses To The Entrepreneurial University, Deanna Barcelona Bullard

USF Tampa Graduate Theses and Dissertations

This study explores how faculty in the social sciences experience and respond to academic capitalism. Academic capitalism is about market and market-like activity at the university and professorial efforts to secure external money. This research expands existing literature which has focused on the hard or natural sciences, and other areas more closely aligned with the market.

Thirty-seven qualitative research interviews were conducted between March and July of 2006 with professors of sociology, criminology, economics at the University of Florida, Florida State University, and the University of South Florida. Results reveal academic capitalism in the social sciences is mostly about grant …

Evaluation Of Unknown Foundations, Ronald W. Florkowski

USF Tampa Graduate Theses and Dissertations

In recent years, bridge foundations have been in the spotlight throughout the nation. Bridges built over running water are susceptible to erosion or scour around their foundations. The reduction in load capacity to piers and abutments pose a safety risk to highway motorists. It has become necessary for engineers to examine and monitor these "scour critical" bridges. The difficulty arises with subsurface foundations of which very little is known about their construction. Hence, the methods applied to analyzing "Unknown Foundations" have become a necessary topic of research.

This thesis explores a method to determine foundation lengths. Similar to Sonic Echo …

Filecules: A New Granularity For Resource Management In Grids, Shyamala Doraimani

USF Tampa Graduate Theses and Dissertations

Grids provide an infrastructure for seamless, secure access to a globally distributed set of shared computing resources. Grid computing has reached the stage where deployments are run in production mode. In the most active Grid community, the scientific community, jobs are data and compute intensive. Scientific Grid deployments offer the opportunity for revisiting and perhaps updating traditional beliefs related to workload models and hence reevaluate traditional resource management techniques.

In this thesis, we study usage patterns from a large-scale scientificGrid collaboration in high-energy physics. We focus mainly on data usage, since data is the major resource for this class of …

Using Frequency Analysis To Determine Wetland Hydroperiod, Lisa D. Foster

USF Tampa Graduate Theses and Dissertations

Wetlands are nominally characterized by, vegetation, presence of saturated soils and/or period and depth of standing water (inundation). Wetland hydroperiod, traditionally defined by the period or duration of inundation, is considered to control the ecological function and resultant plant community. This study seeks to redefine "hydroperiod" to incorporate both surface and subsurface water-level fluctuations, to identify predominant hydroperiod of different wetland types, and to find the range of the water-level fluctuations during the predominant hydroperiod durations. The motivation being that wetland ecological condition is controlled not just by the period of inundation but also by the proximity and depth to …

Investigation Of Zrni, Zrmn2 And Zn(Bh4)2 Metal/Complex Hydrides For Hydrogen Storage, Diego Escobar

USF Tampa Graduate Theses and Dissertations

The demand for efficient and clean fuel alternatives has been increasing in recent years and is expected to become more pronounced in the future. Utilization of hydrogen as a fuel is one of the most promising energy resources due to its easy production, abundance, regeneration and not creation of greenhouse gases during its combustion. Although gaseous hydrogen has a very high energy content per unit weight, its volumetric energy density is rather low. The large scale use of hydrogen as a fuel crucially depends on the development of compact hydrogen storage materials with a high mass content of hydrogen relative …

Tunable Patch Antenna Using Semiconductor And Nano-Scale Barium Strontium Titanate Varactors, Samuel Andrew Baylis

USF Tampa Graduate Theses and Dissertations

Patch antennas are fundamental elements in many microwave communications systems. However, patch antennas receive/transmit signals over a very narrow bandwidth (typically a maximum of 3% bandwidth). Design modifications directed toward bandwidth expansion generally yield 10% to 40% bandwidth.

The series varactor tuned patch antenna configuration was the bandwidth enhancement method explored in this research; this configuration is implemented by dividing a patch antenna into multiple sections and placing varactors across the resultant gaps. In addition to yielding a large bandwidth, the configuration has a number of ancillary benefits, including straightforward integration and design flexibility. Through the research represented by this …

Alumina Nanofluid For Spray Cooling Heat Transfer Enhancement, Aditya Bansal

USF Tampa Graduate Theses and Dissertations

Nanofluids have been demonstrated to be promising for heat transfer enhancement in forced convection and boiling applications. The addition of carbon, copper, and other high-thermal-conductivity material nanoparticles to water, oil, ethylene glycol, and other fluids has been determined to increase the thermal conductivities of these fluids. The increased effective thermal conductivities of these fluids enhance their abilities to dissipate heat in such applications. The use of nanofluids for spray cooling is an extension of the application of nanofluids for enhancement of heat dissipation.

In this investigation, experiments were performed to determine the level of heat transfer enhancement with the addition …

Design Of A Rear-Wheel After-Market Suspension System For Manual Wheelchairs, Rick Daniel Bierworth

USF Tampa Graduate Theses and Dissertations

The objective of this study was to design and build an after-market suspension for the rear wheels of a manual wheelchair. Suspension for wheelchairs is important because it has been reported that the International Organization for Standards' requirements for vibration loads on wheelchair users (ISO 2631-1), are not meet by today's standard wheelchairs. Today's wheelchairs need to be able to absorb everyday shock loads, thereby minimizing the energy transmitted to the user.

The chosen design is based around the concept of adding shock reduction material between the hub of the wheel, and the axel bolt that connects the wheel to …

Improved Techniques For Nonlinear Electrothermal Fet Modeling And Measurement Validation, Charles Passant Baylis Ii

USF Tampa Graduate Theses and Dissertations

Accurate transistor models are important in wireless and microwave circuit design. Large-signal field-effect transistor (FET) models are generally extracted from current-voltage (IV) characteristics, small-signal S-parameters, and large-signal measurements. This dissertation describes improved characterization and measurement validation techniques for FET models that correctly account for thermal and trapping effects.

Demonstration of a customized pulsed-bias, pulsed-RF S-parameter system constructed by the author using a traditional vector network analyzer is presented, along with the design of special bias tees to allow pulsing of the bias voltages. Pulsed IV and pulsed-bias S-parameter measurements can provide results that are electrodynamically accurate; that is, thermal and …

Oceanic Interfaces: Investigations Of Biogeochemical Changes Across Nutriclines And Frontal Boundaries, Lori R. Adornato

USF Tampa Graduate Theses and Dissertations

Biogeochemical changes across oceanic interfaces, and method development to study such changes, are described in this work. The interfaces studied include the Subtropical Front in the Pacific Ocean and the boundary at the base of the euphotic zone. Both interfaces are characterized by accumulations of phytoplankton, although the forcing functions that result in increased biomass are distinctly different.

The Subtropical Front, located at approximately 30°N in the Pacific Ocean, was detected during a cruise in the summer of 2002 by its diagnostic 34.8 salinity outcrop, in spite of the absence of its associated temperature signature. The front displayed elevated concentrations …

Simd Algorithms For Single Link And Complete Link Pattern Clustering, Shankar Arumugavelu

USF Tampa Graduate Theses and Dissertations

Clustering techniques play an important role in exploratory pattern analysis, unsupervised pattern recognition and image segmentation applications. Clustering algorithms are computationally intensive in nature. This thesis proposes new parallel algorithms for Single Link and Complete Link hierarchical clustering. The parallel algorithms have been mapped on a SIMD machine model with a linear interconnection network. The model consists of a linear array of N (number of patterns to be clustered) processing elements (PEs), interfaced to a host machine and the interconnection network provides inter-PE and PE-to-host/host-to-PE communication. For single link clustering, each PE maintains a sorted list of its first logN …

A Compositional Approach To Asynchronous Design Verification With Automated State Space Reduction, Jared Ahrens

USF Tampa Graduate Theses and Dissertations

Model checking is the most effective means of verifying the correctness of asynchronous designs, and state space exploration is central to model checking. Although model checking can achieve very high verification coverage, the high degree of concurrency in asynchronous designs often leads to state explosion during state space exploration. To inhibit this explosion, our approach builds on the ideas of compositional verification. In our approach, a design modeled in a high level description is partitioned into a set of parallel components. Before state space exploration, each component is paired with an over-approximated environment to decouple it from the rest of …

An Investigation Of Community College Students’ Perceptions Of Elements Necessary For Success In Online Study, Jenette Flow

USF Tampa Graduate Theses and Dissertations

Previous studies by professionals in education have investigated the elements that are typical of the successful online student. Studies of the elements required for academic success online from the students' point of view, however, are infrequent.

This study investigated student perceptions of those elements necessary for success in online study; whether students believed differences exist between those elements necessary for success in online study and those necessary for success in traditional classes; and what factors students identify as barriers to successful completion of online courses. A comparison was made of the viewpoints of students who had and who had not …

Channel, Spectrum, And Waveform Awareness In Ofdm-Based Cognitive Radio Systems, Tevfik Yücek

USF Tampa Graduate Theses and Dissertations

The radio spectrum is becoming increasingly congested everyday with emerging technologies and with the increasing number of wireless devices. Considering the limited bandwidth availability, accommodating the demand for higher capacity and data rates is a challenging task, requiring innovative technologies that can offer new ways of exploiting the available radio spectrum. Cognitive radio arises to be a tempting solution to the spectral crowding problem by introducing the notion of opportunistic spectrum usage. Because of its attractive features, orthogonal frequency division multiplexing (OFDM) has been successfully used in numerous wireless standards and technologies. We believe that OFDM will play an important …

Highbrow: A Context Enabled Highlighting Browser, Ronald J. Zucker

USF Tampa Graduate Theses and Dissertations

As the World Wide Web continues to grow, more and more information is retrieved online. A person visiting a Web site has a choice of whether to skip, skim, deep read, bookmark for later revisiting, print a document, or any combination of these options. Recently, several tools have been developed to allow users to digitally annotate Web documents. These tools allow users to highlight, make text notes, and scrape information (a form of copy and paste). This dissertation introduces a new form of annotating, called context highlighting. Context highlighting is the ability to mark the text that surrounds keywords or …

Sulk Localization And Topology Control In Large Scale Heterogeneous Wireless Sensor Networks, Rui Zhang

USF Tampa Graduate Theses and Dissertations

Wireless Sensor Networks (WSNs) continue to evolve as new applications emerge. In the recent past, WSNs were mostly single sink networks with a few number of homogeneous and static sensor nodes. Now, several applications require networks with multiple and moving sinks and targets as well as thousands of heterogeneous devices. However, the same constraints remain: sensor nodes continue to be very limited in resources, posing new challenges in the design of scalable and energy-efficient algorithms and communication protocols to support these new applications. This dissertation first addresses the problem of sink localization in large scale WSNs. A scalable and energy-efficient …

Community Context And Health Disparities Among Older Adults, Helen M. Zayac

USF Tampa Graduate Theses and Dissertations

African Americans, Hispanics, and other minorities in the U.S. continue to face conditions of residential and educational segregation, lower socioeconomic status, and higher rates of mortality than whites. Better theory-based research that uses community and individual level factors to explain how health disparities are created and perpetuated is needed. The Community Context and Health Disparities Model, which extends the work of Schulz and Northridge (2004) with elements described by Williams and Collins (2001), is described. This framework identifies the pathways by which characteristics of the physical, built, social, economic, and healthcare environments impact health and are mediated by individual traits. …

Learning From Biometric Distances: Performance And Security Related Issues In Face Recognition Systems, Pranab Mohanty

USF Tampa Graduate Theses and Dissertations

We present a theory for constructing linear, black box approximations to face recognition algorithms and empirically demonstrate that a surprisingly diverse set of face recognition approaches can be approximated well using a linear model. The construction of the linear model to a face recognition algorithm involves embedding of a training set of face images constrained by the distances between them, as computed by the face recognition algorithm being approximated. We accomplish this embedding by iterative majorization, initialized by classical multi-dimensional scaling (MDS). We empirically demonstrate the adequacy of the linear model using six face recognition algorithms, spanning both template based …

Implementation Of Unmanned Vehicle Control On Fpga Based Platform Using System Generator, Shashikala Narasimha Murthy

USF Tampa Graduate Theses and Dissertations

The goal of this research was to explore a new and improved software development tool for the implementation of control algorithms on Xilinx Field Programmable Gate Arrays (FPGA). The Simulink plug in, System Generator, complements traditional Hardware Description Language (HDL) by providing a higher level graphical language for the development of FPGA designs. The design is then translated into the lower level required by the Xilinx's ISE program. By utilizing this graphical based higher level of abstraction at the design entry level, the requirement of a detailed knowledge of HDL languages is no longer required. Because of this new environment …

Breaking The Typecast: Revising Roles For Coordinating Mixed Teams, Matthew T. Long

USF Tampa Graduate Theses and Dissertations

Heterogeneous multi-agent systems are currently used in a wide variety of situations, including search and rescue, military applications, and off-world exploration, however it is difficult to understand the actions of these systems or naturalistically assign these mixed teams to tasks. These agents, which may be human, robot or software, have different capabilities but will need to coordinate effectively with humans in order to operate. The first and largest contributing factor to this challenge is the processing, understanding and representing of elements of the natural world in a manner that can be utilized by artificial agents. A second contributing factor is …

Effect Of Temperature On Copper Chemical Mechanical Planarization, Veera Raghava R Kakireddy

USF Tampa Graduate Theses and Dissertations

The effects of different process parameters on tribology and surface defects were studied till date, but there has been a very minimal study to understand the effect of slurry temperature during Copper Chemical Mechanical Polishing (CMP). The surface defects such as dishing, erosion and metal loss amount for more than 50% of the defects that hamper the device yield and mainly the electrical properties during the manufacturing process. In this research, the effect of slurry temperature on tribology, surface defects and electrical properties during copper CMP employing different pad materials and slurries has been explored. Experiments were conducted at different …

Micro Coaxial Transmission Lines For Integrated Microwave Circuits, Saravana Prakash Natarajan

USF Tampa Graduate Theses and Dissertations

The research presented in this doctoral dissertation introduces a developmental path to realize micro coaxial transmission lines for wafer-level microwave and millimeter wave circuits. The micro coax lines conceptualized in this research are three-dimensional, with a uniquely low vertical profile of 20 mu m. They are distinguishable from other transmission line topologies due to frequency limitless, cross-talk free performance in high density circuits resulting from the totally shielded construction. Design and optimization was done using equations and electromagnetic simulations. Extensive process development has been carried out to fabricate these devices on CMOS grade silicon wafers using processes amenable to the …

Measurement And Modeling Of The Anhysteretic Magnetization Of Magnetic Cores For Temperature And Frequency Dependent Effects, Jeremy M. Walker

USF Tampa Graduate Theses and Dissertations

Inductors and transformers are electrical devices critical to power conversion systems. The current-voltage (I-V) behavior of these devices is very nonlinear as a result of the magnetic cores used in their construction. However, in the design of these power conversion systems the present state of Spice-based models is limited to low frequency and room temperature effects. An addition to the present model found in many Spice type environments, Jiles-Atherton, is the subject of this work. Chapter 1 of this dissertation introduces the source of these nonlinearities as being a result of the relationship between the magnetic flux density, B, and …

Analysis Of Vtol Mav Use During Rescue And Recovery Operations Following Hurricane Katrina, Kevin S. Pratt

USF Tampa Graduate Theses and Dissertations

There can be little doubt that Hurricane Katrina will always be remembered for the damage and devastation it caused. But it also provided the first opportunity for MAVs to be used and evaluated during Search and Rescue (SAR) as well as recovery operations. Researchers from The Center for Robot-Assisted Search And Rescue (CRASAR) made two separate deployments to areas affected by Hurricane Katrina: one during initial SAR operations and a second deployment during recovery operations 90 days later. Using data and observations from both of these deployments, this work draws four key findings about semi-autonomous Miniature UAV (MAV) operations in …

Defining Service Quality In An Outpatient Clinic With Complex Constituency, Swati Verma

USF Tampa Graduate Theses and Dissertations

The 2001 Institute of Medicine's (I.O.M.) landmark report, Crossing the Quality Chasm: A New Health System for the 21st Century observes that, "[though] medical science and technology have advanced at a rapid pace,...the health care delivery system has floundered in its ability to provide consistently high-quality care" (I.O.M. 2001). The report recommended six quality aims for a twenty-first century health care system; one of them being patient-centered care. It explains patient-centered care as "providing care that is respectful of and responsive to individual patient preferences, needs, and values and ensuring that patient values guide all clinical decisions" (I.O.M. 2001). This …

Ultra-Wideband Electronics, Design Methods, Algorithms, And Systems For Dielectric Spectroscopy Of Isolated B16 Tumor Cells In Liquid Medium, Erick N. Maxwell

USF Tampa Graduate Theses and Dissertations

Quantifying and characterizing isolated tumor cells (ITCs) is of interest in surgical pathology and cytology for its potential to provide data for cancer staging, classification, and treatment. Although the independent prognostic significance of circulating ITCs has not been proven, their presence is gaining clinical relevance as an indicator. However, researchers have not established an optimal method for detecting ITCs. Consequently, this Ph.D. dissertation is concerned with the development and evaluation of dielectric spectroscopy as a low-cost method for cell characterization and quantification. In support of this goal, ultra-wideband (UWB), microwave pulse generator circuits, coaxial transmission line fixtures, permittivity extraction algorithms, …