Digital Commons Network^™

Design And Evaluation Of New Search Paradigms And Power Management For Peer-To-Peer File Sharing, Graciela Perera

USF Tampa Graduate Theses and Dissertations

Current estimates are that more than nine million PCs in the U.S. are part of peer-to-peer (P2P) file sharing overlay networks on the Internet. These P2P hosts generate about 20% of the traffic on the Internet and consume about 7.8 TWh/yr equal to $630 million per year. File search in a P2P network is based on a wasteful paradigm of broadcasting query messages. Reducing P2P overhead traffic to reduce bandwidth waste and enabling power management to reduce electricity usage are clearly of great interest. In this dissertation, two new search paradigms with reduced overhead traffic are investigated. The new Targeted …

Scalable Frameworks And Algorithms For Cluster Ensembles And Clustering Data Streams, Prodip Hore

USF Tampa Graduate Theses and Dissertations

Clustering algorithms are an important tool for data mining and data analysis purposes. Clustering algorithms fall under the category of unsupervised learning algorithms, which can group patterns without an external teacher or labels using some kind of similarity metric. Clustering algorithms are generally iterative in nature and computationally intensive. They will have disk accesses in every iteration for data sets larger than memory, making the algorithms unacceptably slow. Data could be processed in chunks, which fit into memory, to provide a scalable framework. Multiple processors may be used to process chunks in parallel. Clustering solutions from each chunk together form …

Error Equivalence Theory For Manufacturing Process Control, Hui Wang

USF Tampa Graduate Theses and Dissertations

Due to uncertainty in manufacturing processes, applied probability and statistics have been widely applied for quality and productivity improvement. In spite of significant achievements made in causality modeling for control of process variations, there exists a lack of understanding on error equivalence phenomenon, which concerns the mechanism that different error sources result in identical variation patterns on part features. This so called error equivalence phenomenon could have dual effects on dimensional control: significantly increasing the complexity of root cause identification, and providing an opportunity to use one error source to counteract or compensate the others. Most of previous research has …

Investigation Of The Rectenna Concept For Millimeter Wave Applications, Henrry La Rosa

USF Tampa Graduate Theses and Dissertations

This thesis presents the rectifying antenna potential for infrared and millimeter wave energy conversion. Infrared imaging is one of the emerging technologies that have attracted considerable attention in the next generation of military, medical, and commercial applications. Moreover, with the ever-increasing congestion of the electromagnetic spectrum at RF and microwave frequencies and the establishment of firm civilian and military requirements best met by millimeter wave systems, the interest in the technology has grown and is now firmly established. During this work a 2.5GHz slot antenna, a 2.5GHz Schottky diode detector, a CPW-to-Microstrip transition, a fully integrated Rectenna element, and a …

Probabilistic Modeling Of Quantum-Dot Cellular Automata, Saket Srivastava

USF Tampa Graduate Theses and Dissertations

As CMOS scaling faces a technological barrier in the near future, novel design paradigms are being proposed to keep up with the ever growing need for computation power and speed. Most of these novel technologies have device sizes comparable to atomic and molecular scales. At these levels the quantum mechanical effects play a dominant role in device performance, thus inducing uncertainty. The wave nature of particle matter and the uncertainty associated with device operation make a case for probabilistic modeling of the device. As the dimensions go down to a molecular scale, functioning of a nano-device will be governed primarily …

Application And Modeling Of Tio2-Supported Gold Nanoparticles For The Preferential Oxidation Of Carbon Monoxide In Excess Hydrogen, Benjamin Alan Grayson

USF Tampa Graduate Theses and Dissertations

This work begins with a brief overview of heterogeneous, characterization techniques, and current hypotheses about gold mechanisms. This is followed by the initial characterization of custom two-phase-method gold nanoparticles provided by the Interfacial Phenomena and Polymeric Materials research group at USF, the anatase TiO2 support and reference Au/TiO2 catalyst provided by the World Gold Council. In order to verify the ability of the two-phase-method GNP catalyst provided to oxidize CO in excess hydrogen, it was necessary to develop an effluent testing protocol. The first experiments involved 24 hour runs to observe catalyst deactivation. Concerns over cycling effects observed in the …

Transfer Track Versus Workforce Development: Implications For Policy Change In Florida Community Colleges, Karen Griffin

USF Tampa Graduate Theses and Dissertations

Policy-makers intend community colleges to be the primary vehicles for workforce development education and training. In support of this intent, community college mission statements and curricular patterns should clearly indicate a workforce emphasis. Do these statements and curricular patterns reflect policy intent? If not, are resources being directed appropriately? This study was conducted to determine whether the current composition of the overall Florida public community college curriculum and the content of Florida public community college mission and planning statements provided evidence to support Florida leadership policy statements that portray workforce development as a primary component of the community college mission. …

Transport Characteristics Using Nor- Dihydroguaiaretic Acid (Ndga)- Polymerized Collagen Fibers As A Local Drug Delivery System, Eric Guegan

USF Tampa Graduate Theses and Dissertations

Dexamethasone and dexamethasone 21-phosphate were loaded into NDGA-polymerized collagen fibers and release rate studies were performed to calculate their diffusion coefficients. Dexamethasone loaded fibers were placed in a PBS solution for specified time intervals (1, 3, 6, 7, 12, 24, 30, and 48 hours) after which the eluant was removed and analyzed by capillary zone electrophoresis (CZE). CZE is a tool that can be utilized for quantitative analysis of chemical compounds. This data was incorporated into mathematical models to determine the diffusion coefficient. The diffusion coefficient (D) for dexamethasone in NDGA-polymerized collagen fibers is D = 1.86 x 10^{-14 …}

Development Of A Method To Determine Vapor Pressure Data Of Low Volatile Chemicals From A Knudsen Effusion Technique, Andrew R. Harshman

USF Tampa Graduate Theses and Dissertations

Vapor pressure data are vital to understanding impacts that substances, specifically pesticides, may exert on the environment. They enter into atmospheric deposition models for such chemicals which determine the fate and transport of these species in the environment. At normal application temperatures (i.e. room temperature) the vapor pressures of many of these chemicals are too low to be determined by conventional means. An isothermal Knudsen effusion technique was designed and developed in our laboratory for such measurements. The effusion mass as a function of time is measured in our technique using a thickness shear mode (TSM) acoustic wave sensor, which …

Exploring Childcare Professionals' Pedagogical Choice When Guiding Children's Social And Behavioral Development, Mary E. Harper

USF Tampa Graduate Theses and Dissertations

To date the research in the area of social emotional competence has focused on child-based intervention and outcomes. The findings cite effective approaches to assisting children in the area of social and emotional development involving promotion of appropriate social skills, explicit instruction of behavioral expectations, and support for emotional literacy and awareness (Wester --

Stratton, 1990; Hyson, 2004; Fox et al, 2003; Denham & Burton, 1996). These recommended practices requires teacher knowledge and skill, content knowledge in the area of social emotional developmental, and skills in using pedagogical techniques that support acquisition of the aforementioned areas. Educational researchers and specialists …

The Effectiveness And User Perception Of 3-Dimensional Digital Human Anatomy In An Online Undergraduate Anatomy Laboratory, Amy Joanne Hilbelink

USF Tampa Graduate Theses and Dissertations

The primary purpose of this study was to determine the effectiveness of implementing desktop 3-dimensional (3D) stereo images of human anatomy into an undergraduate human anatomy distance laboratory. User perceptions of 2D and 3D images were gathered via questionnaire in order to determine ease of use and level of satisfaction associated with the 3D software in the online learning environment. Mayer's (2001, p. 184) principles of design were used to develop the study materials that consisted of PowerPoint presentations and AVI files accessed via Blackboard. The research design employed a mixed-methods approach. Volunteers each were administered a demographic survey and …

Numerical Modeling And Simulation For Analysis Of Convective Heat And Mass Transfer In Cryogenic Liquid Storage And Hvac&R Applications, Son Hong Ho

USF Tampa Graduate Theses and Dissertations

This work presents the use of numerical modeling and simulation for the analysis of transport phenomena in engineering systems including zero boil-off (ZBO) cryogenic storage tanks for liquid hydrogen, refrigerated warehouses, and human-occupied air-conditioned spaces. Seven problems of medium large spaces in these fields are presented. Numerical models were developed and used for the simulation of fluid flow and heat and mass transfer for these problems. Governing equations representing the conservation of mass, momentum, and energy were solved numerically resulting in the solution of velocity, pressure, temperature, and species concentration(s). Numerical solutions were presented as 2-D and 3-D plots that …

Attitudinal Factors Related To Driving Behaviors Of Young Adults In Belize: An Application Of The Precaution Adoption Process Model, Ismael A. Hoare

USF Tampa Graduate Theses and Dissertations

Young adults' risk-taking attitudes, risk perception, and knowledge of road laws and signs influence their driving behaviors. The adoption of risky driving behaviors increases young adults' risk of motor vehicle crashes. The purpose of this study was to increase the understanding of the factors that lead to increased risks of MVC-related mortality and morbidity for young adults in Belize, to provide support for the development of evidence-based programs, and, more importantly, to investigate the relationships involving young adults' risk-taking attitudes, risk perception, and knowledge of road laws and signs and their relation to driving behaviors. The Precaution Adoption Process Model …

Antibody Targeting Of Non Ionic Surfactant Vesicles To Vascular Inflammation, Elizabeth D. Hood

USF Tampa Graduate Theses and Dissertations

Cardiovascular disease (CVD) and particularly atherosclerosis is a leading cause of morbidity in the developed world. Atherosclerosis and the rupture of vulnerable atherosclerotic plaque cause 70% of deaths from CVD. The progression of atherosclerosis has been identified as a pathological inflammatory process. Targeting atherosclerotic drug therapies to inflammatory markers has emerged as an important and growing research area. The adhesion molecule CD44 has been implicated in the onset and build-up of atherosclerotic lesions throughout the course of development. The research in this dissertation is aimed at targeting anti-inflammatory therapy to activated vascular endothelium with directed with an anti-CD44 antibody, IM7, …

Raman Spectroscopy Of Inas/Gaas Quantum Dots Patterned By Nano-Indentation, Lindsay K. Hussey

USF Tampa Graduate Theses and Dissertations

Patterns of InAs/GaAs quantum dots (QDs) grown by the combination of nanoindentation technique and molecular beam epitaxy were studied. The resulting QDs tend to preferentially nucleate on indented areas rather than other regions. We studied the strain on the indentations, regions surrounding the indents, and non-indented areas. The QD LO mode for the patterned areas shifts by 7 cm-1 when compared to the non-patterned area. The biaxial strain in the indented areas producing this shift is four times larger than that in non-indented areas, explaining the QD preferential formation within these areas. This larger strain suggests that QDs on the …

Numerical Simulation Of Steady State And Transient Heat Transfer In Microchannels, Phaninder Injeti

USF Tampa Graduate Theses and Dissertations

In this project we studied the effect of different parameters on heat transfer in two-dimensional microchannels, microtubes and also tube-in-block heat exchangers for various engineering applications. These included the use of flow restrictions to enhance local heat or mass transfer rate, enhancement of conjugate heat transfer with discrete heating and magnetic coolers (or heaters) associated with magnetic refrigeration system. The results of this research will help in designing the heating or cooling systems and selection of their appropriate geometrical dimensions and materials for specific applications. Types of problems studied in this project are: steady state analysis of forced convection around …

The Relationship Between Technology Integration And Achievement Using Multi-Level Modeling, Tina N. Hohlfeld

USF Tampa Graduate Theses and Dissertations

The purpose of this longitudinal study was to examine the relationship between technology integration indicators and school level achievement. Four years of school level secondary data from publicly available databases maintained by the Florida Department of Education were combined for all public elementary, middle, and high schools in the state. This study examined approximately 2300 schools that participated each year in the Florida Innovates Survey about technology integration between 2003-04 and 2006-07. Complexity theory supported the use of multi-level modeling to examine the relationships between technology integration and outcomes. Three achievement outcomes (reading, mathematics, and writing) and two mediating behavioral …

The Principal’S Role In Building Teacher Leadership Capacity In High-Performing Elementary Schools: A Qualitative Case Study, Rahim Jamal Jones

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to explore how public elementary school principals develop teacher leadership capacity within their schools, as well as the effect of this effort on a school's performance. After examining a variety of sources, such as journal articles and web-based search engines, the researcher determined that there was scant information explaining the process principals undergo to create teacher leadership roles in an effort to develop a high-performing school. To accomplish the goals of this study, salient reports in the field of teacher leadership were reviewed. The insights afforded from these reports guided the researcher in developing …

Crystallization Studies Of Epigallocatechin Gallate, Sheshanka Kesani

USF Tampa Graduate Theses and Dissertations

Flavonoids are a long and well known class of natural products. Their potential health benefits can be attributed to their antioxidant activity, and modulation of cell signaling pathways. Green tea one of the most widely consumed beverages, consist of flavonoids such as catechins and tannins. Epigallocatechin gallate (EGCG) the major catechin of green tea exhibits multiple health benefits due to its antioxidant nature. The radical scavenging activity of EGCG is attributed to its structure. Therefore, a study on molecular features of EGCG would provide valuable information on structural modifications, which may change the physiochemical properties such as bioavailability and solubility. …

Nonlinear Dependence And Extremes In Hydrology And Climate, Shiraj Khan

USF Tampa Graduate Theses and Dissertations

The presence of nonlinear dependence and chaos has strong implications for predictive modeling and the analysis of dominant processes in hydrology and climate. Analysis of extremes may aid in developing predictive models in hydro-climatology by giving enhanced understanding of processes driving the extremes and perhaps delineate possible anthropogenic or natural causes. This dissertation develops and utilizes different set of tools for predictive modeling, specifically nonlinear dependence, extreme, and chaos, and tests the viability of these tools on the real data. Commonly used dependence measures, such as linear correlation, cross-correlogram or Kendall's tau, cannot capture the complete dependence structure in data …

Rkem Implementation For Strain Gradient Theory In Multiple Dimensions, Abhishek Kumar

USF Tampa Graduate Theses and Dissertations

The Reproducing Kernel Element Method (RKEM) implementation of the Fleck-Hutchinson phenomenological strain gradient theory in 1D, 2D and 3D is implemented in this research. Fleck-Hutchinson theory fits within the framework of Touplin- Mindlin theories and deals with first order strain gradients and associated work conjugate higher-order stress. Theories at the intrinsic or material length scales find applications in size dependent phenomena. In elasticity, length scale enters the constitutive equation through the elastic strain energy function which depends on both strain as well as the gradient of rotation and stress. The displacement formulation of the Touplin Mindlin theory involve diffrential equations …

Regulation Of Mdmx Nuclear Import And Degradation By Chk2 And 14-3-3, Cynthia Lebron

USF Tampa Graduate Theses and Dissertations

The MDM2 homolog MDMX is an important regulator of p53 during mouse embryonic development. DNA damage promotes MDMX phosphorylation, nuclear translocation, and degradation by MDM2. Here we show that MDMX copurifies with 14-3-3, and DNA damage stimulates MDMX binding to 14-3-3. Chk2-mediated phosphorylation of MDMX on S367 is important for stimulating 14-3-3 binding, MDMX nuclear import by a cryptic NLS, and degradation by MDM2. Mutation of MDMX S367 inhibits ubiquitination and degradation by MDM2, and prevents MDMX nuclear import. Expression of 14-3-3 stimulates the degradation of phosphorylated MDMX. Chk2 and 14-3-3 cooperatively stimulate MDMX ubiquitination and overcome the inhibition of …

Protégé And Mentor Characteristics: Examining Individual Differences In Effective Mentoring Relationships, Elizabeth Lentz

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to identify and examine the role of dispositional characteristics in effective mentoring relationships. A learning and development framework was incorporated to examine the relationships of protégé and mentor characteristics, mentoring provided, and developmental mentoring outcomes. First, relationships between individual characteristics and mentoring provided were examined. Second, relationships between individual characteristics and partner developmental outcomes were examined. Third, mentoring provided was examined as a mediator of individual characteristics and partner developmental outcomes. The final sample consisted of 93 protégé-mentor pairs. Protégés and mentors were asked to complete an online survey measuring learning goal orientation, locus …

Practical Vibration Evaluation And Early Warning Of Damage In Post-Tensioned Tendons, Jaime Lopez-Sabando

USF Tampa Graduate Theses and Dissertations

Severe corrosion damage and even complete failure was recently discovered in external post-tensioned (PT) tendons of three Florida's pre-cast, segmental bridges over seawater. A key deterioration factor was the formation of large bleed water grout voids at or near the anchorages. Steel corrosion may occur at the grout-void interface or in the air space of the void itself. Since the tendons are critical to the structural integrity of the bridges, reliable and non-intrusive damage detection methods are desirable to manage or prevent future occurrences. In recent years several indirect non-destructive methods have been developed or improved to evaluate the conditions …

Achieving Sobriety: A Narrative Investigation Of Women, Identity, And Relationships, Cara T. Mackie

USF Tampa Graduate Theses and Dissertations

In this dissertation, I explore the question of how women alcoholics achieve sobriety. Using narrative inquiry, I focus on the identity transformation that must occur in order to maintain sobriety and how a drinking self is deconstructed and reconstructed as a sober self. Today, alcoholism is still viewed as stigmatizing in our society and in all Western cultures. The stigma of alcoholism makes it difficult for alcoholics to communicate their experiences to people who have not had similar experiences. However, storytelling in the presence of supportive people has been shown to be a prominent factor in the process of recovery …

Compliant Pediatric Prosthetic Knee, Sebastian Mahler

USF Tampa Graduate Theses and Dissertations

We have designed and examined a compliant knee mechanism that may offer solutions to problems that exist for infants and toddlers who are just learning to walk. Pediatric prosthetic knees on the market today are not well designed for infants and toddlers for various reasons. Children at this age need a prosthetic that is light in weight, durable, and stable during stance. Of the eleven knees on the market for children, all but three are polycentric or four-bar knees, meaning they have multiple points of movement. Polycentric knees are popular designs because they offer the added benefit of stable stance …

The Baccalaureate Community Colleges In Florida: A Policy Evaluation, Nicholas Manias

USF Tampa Graduate Theses and Dissertations

This study sought to determine if community college baccalaureate programs in Florida were fulfilling the goals that were set forth in the legislation that created them. The study examined whether the baccalaureate level education programs at three community colleges in Florida were increasing access to baccalaureate education. The study investigated enrollment trends at all public institutions in Florida, reasons why students chose the community colleges for their upper division education, alternative plans students may have had if these programs did not exist, whether the limited number of baccalaureate programs at the community colleges impacted students' choice of major, and how …

On The Theory Of Records And Applications, Alfred Kubong Mbah

USF Tampa Graduate Theses and Dissertations

No abstract provided.

The Effect Of Optional Real World Application Projects On Mathematics Achievement Among Undergraduate Students, David Milligan

USF Tampa Graduate Theses and Dissertations

Many undergraduate students enrolled in institutions of higher learning wish to connect their learning to real life experiences. By linking reality to academics, students see first hand the practical value in their studies. The purpose of this study was to critically analyze the practice of application projects in undergraduate mathematics courses to determine if, and if so how, students benefit from optional real world application projects. The study was limited to specific courses within a non-math major's undergraduate mathematics program of study at one large research university. Until the appearance of "The Mathematics Umbrella: Modeling and Education" (Grinshpan, 2005), no …

Hydrological Connectivity Between Clay Settling Areas And Surrounding Hydrological Landscapes In The Phosphate Mining District, Peninsular Florida, Usa, Kathryn E. Murphy

USF Tampa Graduate Theses and Dissertations

The objective of this study was to use applied and naturally-occurring geochemical tracers to study the hydrology of clay settling areas (CSAs) and the hydrological connectivity between CSAs and surrounding hydrological landscapes. The study site is located on the Fort Meade Mine in Polk County, Florida. The surface of the CSA is covered in desiccation cracks which swell and shrink in response to wetting and drying. Bromide was used as an applied tracer to study hydrological processes in the upper part of the CSA. Bromide infiltrated rapidly and perched on an uncracked massive sublayer. Bromide concentrations attenuated in the upper …