Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 236 pages. / Thesis (Ph.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Particulate nitrates play important roles in the atmosphere. They consist mainly of NH4NO3 and NaNO3, products from the reactions of gaseous HNO3 with gaseous NH3 and sea salt, respectively. The gas-to-particle phase conversion of nitrate changes its deposition characteristics and ultimately changes the transport and deposition rates of the locally produced species. Studies were conducted to develop background information on the particle concentrations and size distributions and the chemistry and kinetics behind the interactions. The predominant nitrate species in the Tampa Bay area was identified as coarse mode NaNO3. NH4NO3 was not detected as it has high volatility at ambient temperatures. Spatial distribution sampling determined a gradient of NaCl and NaNO3 with increased distance from the coastal shore and an increase in the gas-to-particle conversion of nitric acid along a predominant air mass trajectory. / ABSTRACT: The EQUISOLV II thermodynamic equilibrium model was evaluated. It was determined that the model can be used to predict gas and size-distributed particulate matter concentrations. The model was also used to examine the gas-to-particle partitioning of nitric acid to nitrate by NaCl and CaCO3. Both sodium and calcium partitioned nitrate to the particle phase. The magnitude of the partitioning was directly dependent on the equilibrium coefficients. The fine mode percentage of the total nitrate was determined using two methods. The results were used to expand the current data set to account for the coarse mode nitrate, and they indicated that particle nitrate accounted for 9% of the total nitrogen deposition flux to Tampa Bay. The formation of particle nitrate was examined using a nitrate accumulation model. / ABSTRACT: Results indicated that the equilibrium time for particles less than 10 um in diameter was significantly less than their atmospheric residence time, with fastest conversion occurring under the highest relative humidity conditions. This information is vital in the development of atmospheric nitrogen dry deposition estimates, which are used to assess water quality and nutrient loading. These data can be used to determine air-monitoring strategies and to develop models that account for the coarse particle nitrogen species. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 145 pages. / Thesis (Ph.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: In this dissertation we introduce several novel techniques for performing data mining on web documents which utilize graph representations of document content. Graphs are more robust than typical vector representations as they can model structural information that is usually lost when converting the original web document content to a vector representation. For example, we can capture information such as the location, order and proximity of term occurrence, which is discarded under the standard document vector representation models. Many machine learning methods rely on distance computations, centroid calculations, and other numerical techniques. Thus many of these methods have not been applied to data represented by graphs since no suitable graph-theoretical concepts were previously available. We introduce the novel Graph Hierarchy Construction Algorithm (GHCA), which performs topic-oriented hierarchical clustering of web search results modeled using graphs. / ABSTRACT: The system we created around this new algorithm and its prior version is compared with similar web search clustering systems to gauge its usefulness. An important advantage of this approach over conventional web search systems is that the results are better organized and more easily browsed by users. Next we present extensions to classical machine learning algorithms, such as the k-means clustering algorithm and the k-Nearest Neighbors classification algorithm, which allows the use of graphs as fundamental data items instead of vectors. We perform experiments comparing the performance of the new graph-based methods to the traditional vector-based methods for three web document collections. Our experimental results show an improvement for the graph approaches over the vector approaches for both clustering and classification of web documents. / ABSTRACT: An important advantage of the graph representations we propose is that they allow the computation of graph similarity in polynomial time; usually the determination of graph similarity with the techniques we use is an NP-Complete problem. In fact, there are some cases where the execution time of the graph-oriented approach was faster than the vector approaches. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Title from PDF of title page. / Document formatted into pages; contains 71 pages. / Thesis (M.S.E.E.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: This thesis concentrates on RF/microwave characterization and modeling of planar spiral inductors and pad stack parasitics. The inductors varied in size from 1.9 to 15.3 nH. Several approaches were examined for modeling the planar spiral inductors. The approach developed herein is built around an existing composite model (available in commercial computer-aided design software), with added series and shunt impedances at both the input and output of the existing composite model. Artificial neural network (ANN) software was used to determine the correction impedance values. Another approach investigated was to model the S-parameters of the inductor using a space- mapping model of the input parameters for the existing model. The correction impedance modeling approach was theoretically sound but the level of accuracy need for the ANN model was not obtainable. The space mapping approach had merit but a substrate and parameter scalable model could not be achieved. / ABSTRACT: A pad stack is a section of microstrip line that a surface mounted element is affixed to; these pad stacks are standardized for specific element sizes, so for example any 0805 (80 mils by 50 mils) element may have the same pad stack whether it is a capacitor, inductor or resistor. The pad stack models were necessary because a capacitor model originally developed at the University of South Florida did not include parasitic effects for different input connections. The pad stack parasitic models can be broken down into three types: dual-input, tri-input, and quad-input. Each of the dual- and tri- input models have input angles of either 0 degrees, 45 degrees, or 90 degrees. The models were developed using a combination of microstrip and lumped elements. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Title from PDF of title page. / Document formatted into pages; contains 86 pages. / Thesis (M.S.Ch.E.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The goal of this thesis is to present the design and development of a chemical vapor deposition reactor for the growth of high quality homoepitaxy silicon carbide films for electronic device applications. The work was performed in the Nanomaterials and Nanomanufacturing Research Center at the University of South Florida from 8/2001-5/2003. Chemical vapor deposition (CVD) is the technique of choice for SiC epitaxial growth. Epitaxial layers are the building blocks for use in various semiconductor device applications. This thesis reports on a SiC epitaxy process where a carrier gas (hydrogen) is saturated with reactive precursors (silane and propane) which are then delivered to a semiconductor substrate resting on a RF induction heated SiC coated graphite susceptor. Growth proceeds via a series of heterogeneous chemical reactions with several steps, including precursor adsorption, surface diffusion and desorbtion of volatile by-products. / ABSTRACT: The design and development of a reactor to make this process controlled and repeatable can be accomplished using theoretical and empirical tools. Fluid flow modeling, reactor sizing, low-pressure pumping and control are engineering concepts that were explored. Work on the design and development of an atmospheric pressure cold-wall CVD (APCVD) reactor will be presented. A detailed discussion of modifications to this reactor to permit hot-wall, low-pressure CVD (LPCVD) operation will then be presented. The consequences of this process variable change will be discussed as well as the necessary design parameters. Computational fluid dynamic (CFD) calculations, which predict the flow patterns of gases in the reaction tube, will be presented. Feasible CVD reactor design that results in laminar fluid flow control is a function of the prior mentioned techniques and will be presented. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Title from PDF of title page. / Document formatted into pages; contains 48 pages. / Thesis (M.S.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: C-Terminal glycine-extended prohormones are enzymatically converted to á-amidated peptides, by peptidylglycine á-amidating monooxygenase (PAM). PAM is a bifunctional enzyme with two catalytic domains: peptidylglycine á -hydroxylating monooxygenase (PHM) and peptidylglycine peptidylglycineaminoglycolate lyase (PAL). PAM has a significant role in the proliferation of androgen-independent prostate cancer. Thus, the inhibition of PAM could halt cancer growth. Hippurate and hippurate analogs were used as lead compounds for developing inhibitors for PAM. The hippurate analogs exhibiting the highest affinity to PAM (lowest inhibition constant) did inhibit the growth of human androgen-independent prostate cancer DU 145 cells. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Title from PDF of title page. / Document formatted into pages; contains 124 pages. / Thesis (Ph.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: As technology scales down and CMOS circuits are powered by lower supply voltages, standby leakage current becomes significant. A behavioral level framework for the synthesis of data-paths with low leakage power is presented. There has been minimal work done on the behavioral synthesis of low leakage datapaths. We present a fast architectural simulator for leakage (FASL) to estimate the leakage power dissipated by a system described hierarchically in VHDL. FASL uses a leakage power model embedded into VHDL leafcells. These leafcells are characterized for leakage accurately using HSPICE. We present results which show that FASL measures leakage power significantly faster than HSPICE, with less than a 5% loss in accuracy, compared to HSPICE. We present a comprehensive framework for synthesizing low leakage power data-paths using a parameterized Multi-threshold CMOS (MTCMOS) component library. / ABSTRACT: The component library has been characterized for leakage power and delay as a function of sleep transistor width. We propose four techniques for minimization of leakage power during behavioral synthesis: (1) leakage power management using MTCMOS modules; (2) an allocation and binding algorithm for low leakage based on clique partitioning; (3) selective binding to MTCMOS technology, allowing the designer to have control over the area overhead; and (4) a performance recovery technique based on multi-cycling and introduction of slack, to alleviate the loss in performance attributed to the introduction of MTCMOS modules in the data-path. Finally, we propose two iterative search based techniques, based on Tabu search, to synthesize low leakage data-paths. The first technique searches for low leakage scheduling options. The second technique simultaneously searches for a low leakage schedule and binding. It is shown that the latter technique of unified search is more robust. / ABSTRACT: The quality of results generated bytabu-based technique are superior to those generated by simulated annealing (SA) search technique. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 223 pages. / Thesis (Ph.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: This study addresses research reporting practices and protocols by bridging the gap from the theoretical and conceptual debates typically found in the literature with more realistic applications using data from published research. Specifically, the practice of using findings of statistical analysis as the primary, and often only, basis for results and conclusions of research is investigated through computing effect size and confidence intervals and considering how their use might impact the strength of inferences and conclusions reported. Using a sample of published manuscripts from three peer-rviewed journals, central quantitative findings were expressed as dichotomous hypothesis test results, point estimates of effect sizes and confidence intervals. Studies using three different types of statistical analyses were considered for inclusion: t-tests, regression, and Analysis of Variance (ANOVA). / ABSTRACT: The differences in the substantive interpretations of results from these accomplished and published studies were then examined as a function of these different analytical approaches. Both quantitative and qualitative techniques were used to examine the findings. General descriptive statistical techniques were employed to capture the magnitude of studies and analyses that might have different interpretations if althernative methods of reporting findings were used in addition to traditional tests of statistical signficance. Qualitative methods were then used to gain a sense of the impact on the wording used in the research conclusions of these other forms of reporting findings. It was discovered that tests of non-signficant results were more prone to need evidence of effect size than those of significant results. / ABSTRACT: Regardless of tests of signficance, the addition of information from confidence intervals tended to heavily impact the findings resulting from signficance tests. The results were interpreted in terms of improving the reporting practices in applied research. Issues that were noted in this study relevant to the primary focus are discussed in general with implicaitons for future research. Recommendations are made regarding editorial and publishing practices, both for primary researchers and editors. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Title from PDF of title page. / Document formatted into pages; contains 132 pages. / Thesis (M.A.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The present study examined the relationship between individual, family, and school variables and both bullying and victimization. Approximately equal numbers of males and females (N = 1185 and 1174, respectively) were randomly selected from classrooms in 11 middle schools across 6th, 7th, and 8th grades. Students completed questionnaires including items from each domain. Questionnaires assessed bullying and victimization, internalizing and externalizing behaviors, family factors, and school variables. In addition, teachers of the selected classrooms completed a brief rating scale on each of the students, which assessed student moodiness, behavioral difficulties, and learning problems. Achievement and discipline records data were obtained. Based on their responses to critical items, participants were categorized into Bully, Victim, Bully/Victim, and comparison Control groups. / ABSTRACT: Multivariate analyses, with follow-up univariate and discriminant function analyses, tested the association of variables within the individual, family, teacher report, and school domains with bullying group membership. Analyses were examined by grade and gender effects as well. Results indicated that variables within each of the domains significantly contributed to differences between bullying groups, by grade and gender. Specifically, bullies and bully/victims appeared to have the poorest reported adjustment in terms of behavioral difficulties, family functioning, and school variables, while both victims and bully/victims experienced greater internalizing difficulties. Bullies and bully/victims tended to have the poorest outcomes; however, victims reported poorer peer relationships and perceptions of school. Overall, depression, anxiety, and the expression of anger accounted for the majority of group differences. / ABSTRACT: School variables, particularly peer relationships, a sense of school spirit, and perceptions of climate and adult availability at school, played a secondary role in explaining differences among groups. These findings varied by gender and grade. Illustratively, bullying intervention programs could, in part, focus on those characteristics that are more strongly related to certain groups of students (i.e., anger expression for females and school conditions for younger students). / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Title from PDF of title page. / Document formatted into pages; contains 84 pages. / Thesis (M.S.E.E.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: It is clear that Cryptography is computationally intensive. It is also known that embedded systems have slow clock rates and less memory. The idea for this thesis was to study the possibilities for analysis of cryptography on embedded systems. The basic approach was the implementation of cryptographic algorithms on high-end, state-of-the-art, DSP chips in order to study the various parameters that optimize the performance of the chip while keeping the overhead of encryption and decryption to a minimum. Embedded systems are very resource sensitive. An embedded system is composed of different components, which are implemented in both hardware and software. Therefore, hardware-software co-synthesis is a crucial factor affecting the performance of embedded systems. Encryption algorithms are generally classified as data-dominated systems rather than ubiquitous control-dominated systems. Data-dominated systems have a high degree of parallelism. / ABSTRACT: Embedded systems populate the new generation gadgets such as cell phones and Smartcards where the encryption algorithms are obviously an integral part of the system. Due to the proliferation of embedded systems in all the current areas, there is a need for the systematic study of encryption techniques from the embedded systems point of view. This thesis explored the different ways encryption algorithms can be made to run faster with much less memory. Some of the issues investigated were overlapped scheduling techniques for high-level synthesis, structural partitioning, real-time issues, reusability and functionality, random number and unique key generators, seamless integration of cryptographic code with other applications and architecture specific optimization techniques. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Professional research project (Au.D.)--University of South Florida, 2003. / Title from PDF of title page. / Document formatted into pages; contains 25 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Understanding speech in background noise is occasionally difficult for normal hearing listeners and is often impossible for the listener with sensorineural hearing loss. The ability to understand speech in noise depends upon multiple factors such as the characteristics of the speech signal, the signal-to-noise ratio, and the listener's degree of hearing impairment. A routine hearing evaluation usually does not provide ample information about a listener's functional communication abilities. The Hearing-in-Noise Test (HINT) developed by The House Ear Institute provides an efficient and reliable method for evaluating an individual's suprathreshold speech understanding ability in quiet and in noise. / ABSTRACT: The purpose of this pilot study was to investigate monaural speech reception thresholds for sentences (RTS) in quiet and in noise using the standardized Hearing-in-Noise Test (HINT). Data was collected from one clinical setting using twenty-five subjects with bilateral normal hearing (WNL) and twenty subjects with bilaterally symmetrical sensorineural hearing loss (SNHL). Subject age ranged from 40 to 65 years. The study results were generally in agreement with the HINT norms. It was concluded that administering the HINT monaurally under headphones could differentiate between normal hearing individuals and individuals with cochlear hearing loss. The SNHL group exhibited higher RTSs than the WNL group in both quiet and in noise. The mean RTS difference between the two groups in quiet was 14.56 dB while the mean RTS difference in noise was only 2.85 dB. Surprisingly, the difference between the two subject groups in quiet was greater than was expected. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.