Current Search: Mapping (x)
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Title
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Role of Mycobacterium avium paratuberculosis (MAP) and TNFSF15 SNPs on TL1A in CD.
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Creator
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Hassouneh, Sayf Al-Deen, Naser, Saleh, Yooseph, Shibu, Parthasarathy, Sampath, University of Central Florida
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Abstract / Description
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Tumor Necrosis Factor-Like Ligand 1a (TL1A) is a cytokine encoded by Tumor Necrosis Factor Super Family 15 gene (TNFSF15) gene mostly in endothelial cells which binds to T-cells and foments the production of pro-inflammatory cytokines including TNF-?, IL-6, IL-1b, IFN- ? and IL-13. TL1A level is elevated in inflammatory diseases including Crohn's Disease (CD). Although Single Nucleotide Polymorphisms (SNPs) in TNFSF15 have been reported in CD, no studies have investigated the effect of these...
Show moreTumor Necrosis Factor-Like Ligand 1a (TL1A) is a cytokine encoded by Tumor Necrosis Factor Super Family 15 gene (TNFSF15) gene mostly in endothelial cells which binds to T-cells and foments the production of pro-inflammatory cytokines including TNF-?, IL-6, IL-1b, IFN- ? and IL-13. TL1A level is elevated in inflammatory diseases including Crohn's Disease (CD). Although Single Nucleotide Polymorphisms (SNPs) in TNFSF15 have been reported in CD, no studies have investigated the effect of these SNPs on TL1A, inflammation, and susceptibility to Mycobacterium avium subspecies paratuberculosis (MAP) infection. MAP is a strong candidate in CD pathogenesis. This study is designed to elucidate the combined effect of MAP and SNPs in TNFSF15 (rs4263839, rs7848647, rs6478108, or rs6478109) on TL1A secretion and downstream effect on pro-inflammatory cytokines. Peripheral blood from CD and healthy subjects was analyzed for MAP DNA, TNFSF15 genotyping, circulating TL1A level, and IFN- ? and TNF-? gene expression. Our data is first to report that rs4263839, rs7848647, rs6478108, and rs6478109 in TNFSF15 resulted in increase in circulating TL1A level in healthy and CD samples. Specifically, in CD samples with rs7848647, the average TL1A level was 146.9 pg/mL (&)#177; 124.5 compared 62.4 pg/mL (&)#177; 82.8 in normal samples. Similarly, TL1A level in CD samples with rs6478109 was 141.9 pg/mL (&)#177; 127.7 compared to 71.5 pg/mL (&)#177; 88.4 in normal samples (p(<)0.05). All 4 SNPs resulted in significant elevation in TL1A level in healthy samples (p(<)0.05). Moreover, IFN-? expression was significantly higher, by approximately 1.6-fold in CD patients with SNPs relative to CD patients with no SNPs (p(<)0.05). Interestingly, SNPs in TNFS15 had no significant effect on TNF-? expression. MAP was detected in the blood of 63% of CD compared to 6% healthy subjects (p(<).001). The data did not support a correlation between MAP presence and circulating TL1A levels, and no correlation between SNPs in TNSF15 and MAP susceptibility. This study strongly suggests, that SNPs in TNFSF15 increase TL1A levels and may be a contributory factor to the inflammation experienced by CD patients. Over all, the study emphasizes the need for a pharmacogenomic approach in treatment delivery for patients with CD by using TNFSF15 SNPs to identify patients that would benefit from biologics targeting TL1A rather than TNF-? for more efficacious treatment regiments for CD patients.
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Date Issued
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2018
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Identifier
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CFE0007189, ucf:52263
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007189
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Title
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Mapping Addiction: A Digital Psychogeographic Approach to America's Addiction Epidemic.
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Creator
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Benjamin, Clayton, Mauer, Barry, Applen, JD, Janz, Bruce, Oleksiak, Timothy, University of Central Florida
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Abstract / Description
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iiiABSTRACTFocusing on policy consultation, my dissertation consults on the current US addiction epidemic and aims to answer, (")What is our disposition to addiction?(") Borrowing and clarifying Ulmer's MEmorial method, as established in his text Electronic Monuments, the dissertation combines the ancient Greek practice of theoria, Deleuzian theory, and psychogeographic counter-mapping methods to trace ways in which ideological apparatuses construct addiction. The aim of the dissertation is...
Show moreiiiABSTRACTFocusing on policy consultation, my dissertation consults on the current US addiction epidemic and aims to answer, (")What is our disposition to addiction?(") Borrowing and clarifying Ulmer's MEmorial method, as established in his text Electronic Monuments, the dissertation combines the ancient Greek practice of theoria, Deleuzian theory, and psychogeographic counter-mapping methods to trace ways in which ideological apparatuses construct addiction. The aim of the dissertation is to reveal an abject value by constructing MEmorials which provide space for individuals to mourn loss and see their relation to that loss. Through mourning, individuals strengthen their ties to other community members and new policy can be made possible. Currently there is not an AIDS-like quilt for the victims of the addiction epidemic; therefore, the dissertation proposes the construction of a physical and electronic MEmorial to addiction. By conducting a psychogeography, a method directly tied to logic and reasoning appropriate to electracy, I traced the abject value of desire as it is constructed through the assemblages that construct the values of the Bradenton, FL community. The psychogeography revealed a categorical image (")DE(") which I traced through the ideological state apparatuses working their effects on Bradenton, FL. The image also connects to Bradenton, FL to the larger National War on Drugs through the star emblem of John Wayne. Concluding from the method, I argue to create a MEmorial to addiction at the John Wayne Birthplace Museum to reveal the horror of our communal desires and call for national drug policy reform.
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Date Issued
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2019
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Identifier
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CFE0007785, ucf:52358
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007785
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Title
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Has the Song Remained the Same?: Perceptions of Effectiveness in Family Safety Work.
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Creator
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Marshall, Debra, Lynxwiler, John, Wright, James, Jasinski, Jana, Jewett, Aubrey, University of Central Florida
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Abstract / Description
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National and international research on governmental privatization efforts reflects myriad successes and failures. However, little is known about the effectiveness of family safety privatization efforts in the state of Florida. In Brevard County, Florida, family safety privatization efforts have been underway for several years now, and while evaluations are taking place, they do not reflect one key piece of information(-)the perceptions of family safety workers. A snowball sample was obtained...
Show moreNational and international research on governmental privatization efforts reflects myriad successes and failures. However, little is known about the effectiveness of family safety privatization efforts in the state of Florida. In Brevard County, Florida, family safety privatization efforts have been underway for several years now, and while evaluations are taking place, they do not reflect one key piece of information(-)the perceptions of family safety workers. A snowball sample was obtained from former and current child safety workers and open- and closed-ended questions were administered with a total of 15 former and current family safety workers who work or worked for several different public and private family safety agencies within Brevard County, Florida. Information was obtained regarding perceptions of privatization to adequately and more efficiently do the work of public entities. The results show two primary areas of interest. The model of care which has been instituted post-privatization (CARES) has been perceived as more effective than the former state model; the strongest problematic themes that developed concerned power, control, and the perception of unfairness. These themes are explored using a backwards mapping approach and recommendations for continued growth and cohesion are explored.
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Date Issued
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2012
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Identifier
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CFE0004208, ucf:49021
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004208
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Title
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IMPROVING PERFORMANCE AND PROGRAMMER PRODUCTIVITY FOR I/O-INTENSIVE HIGH PERFORMANCE COMPUTING APPLICATIONS.
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Creator
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Sehrish, Saba, Wang, Jun, University of Central Florida
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Abstract / Description
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Due to the explosive growth in the size of scientific data sets, data-intensive computing is an emerging trend in computational science. HPC applications are generating and processing large amount of data ranging from terabytes (TB) to petabytes (PB). This new trend of growth in data for HPC applications has imposed challenges as to what is an appropriate parallel programming framework to efficiently process large data sets. In this work, we study the applicability of two programming models ...
Show moreDue to the explosive growth in the size of scientific data sets, data-intensive computing is an emerging trend in computational science. HPC applications are generating and processing large amount of data ranging from terabytes (TB) to petabytes (PB). This new trend of growth in data for HPC applications has imposed challenges as to what is an appropriate parallel programming framework to efficiently process large data sets. In this work, we study the applicability of two programming models (MPI/MPI-IO and MapReduce) to a variety of I/O-intensive HPC applications ranging from simulations to analytics. We identify several performance and programmer productivity related limitations of these existing programming models, if used for I/O-intensive applications. We propose new frameworks which will improve both performance and programmer productivity for the emerging I/O-intensive applications. Message Passing Interface (MPI) is widely used for writing HPC applications. MPI/MPI- IO allows a fine-grained control of assigning data and task distribution. At the programming frameworks level, various optimizations have been proposed to improve the performance of MPI/MPI-IO function calls. These performance optimizations are provided as various function options to the programmers. In order to write an efficient code, they are required to know the exact usage of the optimization functions, hence programmer productivity is limited. We propose an abstraction called Reduced Function Set Abstraction (RFSA) for MPI-IO to reduce the number of I/O functions and provide methods to automate the selection of appropriate I/O function for writing HPC simulation applications. The purpose of RFSA is to hide the performance optimization functions from the application developer, and relieve the application developer from deciding on a specific function. The proposed set of functions relies on a selection algorithm to decide among the most common optimizations provided by MPI-IO. Additionally, many application scientists are looking to integrate data-intensive computing into computational-intensive High Performance Computing facilities, particularly for data analytics. We have observed several scientific applications which must migrate their data from an HPC storage system to a data-intensive one. There is a gap between the data semantics of HPC storage and data-intensive system, hence, once migrated, the data must be further refined and reorganized. This reorganization must be performed before existing data-intensive tools such as MapReduce can be effectively used to analyze data. This reorganization requires at least two complete scans through the data set and then at least one MapReduce program to prepare the data before analyzing it. Running multiple MapReduce phases causes significant overhead for the application, in the form of excessive I/O operations. For every MapReduce application that must be run in order to complete the desired data analysis, a distributed read and write operation on the file system must be performed. Our contribution is to extend Map-Reduce to eliminate the multiple scans and also reduce the number of pre-processing MapReduce programs. We have added additional expressiveness to the MapReduce language in our novel framework called MapReduce with Access Patterns (MRAP), which allows users to specify the logical semantics of their data such that 1) the data can be analyzed without running multiple data pre-processing MapReduce programs, and 2) the data can be simultaneously reorganized as it is migrated to the data-intensive file system. We also provide a scheduling mechanism to further improve the performance of these applications. The main contributions of this thesis are, 1) We implement a selection algorithm for I/O functions like read/write, merge a set of functions for data types and file views and optimize the atomicity function by automating the locking mechanism in RFSA. By running different parallel I/O benchmarks on both medium-scale clusters and NERSC supercomputers, we show an improved programmer productivity (35.7% on average). This approach incurs an overhead of 2-5% for one particular optimization, and shows performance improvement of 17% when a combination of different optimizations is required by an application. 2) We provide an augmented Map-Reduce system (MRAP), which consist of an API and corresponding optimizations i.e. data restructuring and scheduling. We have demonstrated up to 33% throughput improvement in one real application (read-mapping in bioinformatics), and up to 70% in an I/O kernel of another application (halo catalogs analytics). Our scheduling scheme shows performance improvement of 18% for an I/O kernel of another application (QCD analytics).
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Date Issued
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2010
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Identifier
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CFE0003236, ucf:48560
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0003236
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Title
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THE IMPACT OF UNIVERSAL DESIGN FOR LEARNING-REPRESENTATION PRACTICES ON CONCEPT MAPS AND THE DEVELOPMENT OF QUALITY SCIENTIFIC EXPLANATIONS.
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Creator
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Finnegan, Lisa, Dieker, Lisa, University of Central Florida
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Abstract / Description
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ABSTRACT The purpose of this action research project was to determine how my practice of implementing Universal Design for Learning-Representation (UDL-R) principles influenced my studentsÃÂ' understanding of content and enhanced their ability to organize their knowledge using concept maps. A secondary purpose of this action research project was to determine if student created concept maps served as a useful tool to enrich studentsÃÂ' written...
Show moreABSTRACT The purpose of this action research project was to determine how my practice of implementing Universal Design for Learning-Representation (UDL-R) principles influenced my studentsÃÂ' understanding of content and enhanced their ability to organize their knowledge using concept maps. A secondary purpose of this action research project was to determine if student created concept maps served as a useful tool to enrich studentsÃÂ' written scientific explanations. Students in this study completed concept maps and wrote explanations about adaptations before and after participating in lessons enriched with UDL-R principles that included the use of multi-media sources, website searches, and trade books. The processes used to collect data for this action research project were concept maps, written explanations, student notes, and videotaped accounts of learning from UDL-R principles. The themes that emerged were deeper content understanding for students and greater engagement in learning through UDL-R practices as evidenced through student notes, student discussions and videotaped accounts. The students in this study showed minimal change in the total average scores on concept maps with mixed results for males versus female studentsÃÂ' scores. Although studentsÃÂ' concept maps and written explanations indicated minimal improvement or change, their notes listing thirty to over one hundred facts and their comments indicated their interest and engagement in the learning process supported by UDL-R practices.
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Date Issued
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2010
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Identifier
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CFE0003045, ucf:48358
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0003045
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Title
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An Assessment of Trace Elements Distribution in Teeth Utilizing a Sample Group from Postclassic Lamanai: The Application of LA-ICP-MS in Bioarchaeology and Forensics.
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Creator
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Hawkins, Michelle, Schultz, John, Williams, Lana, Baudelet, Matthieu, University of Central Florida
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Abstract / Description
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Trace element analysis of skeletal remains and teeth is a common research technique in biological and forensic anthropology. In particular, LA-ICP-MS has become a widely-accepted tool for analyzing and mapping the distribution of trace elements in teeth. Investigation into the relative spectral intensities and spatial distribution of thirteen trace isotopes (13C, 24Mg, 27Al, 31P, 44Ca, 47Ti, 52Cr, 55Mn, 56Fe, 66Zn, 88Sr, 138Ba, 208Pb) within teeth was undertaken using LA-ICP-MS. The total...
Show moreTrace element analysis of skeletal remains and teeth is a common research technique in biological and forensic anthropology. In particular, LA-ICP-MS has become a widely-accepted tool for analyzing and mapping the distribution of trace elements in teeth. Investigation into the relative spectral intensities and spatial distribution of thirteen trace isotopes (13C, 24Mg, 27Al, 31P, 44Ca, 47Ti, 52Cr, 55Mn, 56Fe, 66Zn, 88Sr, 138Ba, 208Pb) within teeth was undertaken using LA-ICP-MS. The total archaeological sample of teeth (N=26) was comprised of four tooth types (UCI, ULI, UPM1, and UPM2) and 18 individuals from a Postclassic Lamanai site. In preparation for analysis, teeth sectioned down the center using a low-speed saw. Maps were created using the laser ablation system and MATLAB(&)#174; software. The frequency of each isotope detected at low, moderate, and high intensities at each of the six defined tooth locations was calculated. The inner dentine and the outer root border were the two areas that most commonly exhibited the highest intensities of isotopes. Detection of major structural isotopes (44Ca and 31P) was similar in both spatial locations and relative intensity across all teeth. In comparison, detection of more minor isotopes, while similar in spatial locations across all teeth, varied in relative intensity per individual sample. The frequency that each isotope was detected also varied by tooth type. These findings demonstrate the disparities between different types of dental tissue for retaining trace elements and serve to illuminate possible sources of external exposure and internal bioavailability influencing interindividual variation within the Lamanai sample population. Variation in isotope frequency based on tooth type may be due to developmental properties and/or changes in diet during early life. Ultimately, teeth act as storehouses of trace elements, and maps of isotopic distribution in teeth help reveal how individuals are influenced by both biological processes and cultural activities.
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Date Issued
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2017
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Identifier
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CFE0006881, ucf:51722
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006881
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Title
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On the range of the Attenuated Radon Transform in strictly convex sets.
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Creator
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Sadiq, Kamran, Tamasan, Alexandru, Nashed, M, Katsevich, Alexander, Dogariu, Aristide, University of Central Florida
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Abstract / Description
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In the present dissertation, we characterize the range of the attenuated Radon transform of zero, one, and two tensor fields, supported in strictly convex set. The approach is based on a Hilbert transform associated with A-analytic functions of A. Bukhgeim. We first present new necessary and sufficient conditions for a function to be in the range of the attenuated Radon transform of a sufficiently smooth function supported in the convex set. The approach is based on an explicit Hilbert...
Show moreIn the present dissertation, we characterize the range of the attenuated Radon transform of zero, one, and two tensor fields, supported in strictly convex set. The approach is based on a Hilbert transform associated with A-analytic functions of A. Bukhgeim. We first present new necessary and sufficient conditions for a function to be in the range of the attenuated Radon transform of a sufficiently smooth function supported in the convex set. The approach is based on an explicit Hilbert transform associated with traces of the boundary of A-analytic functions in the sense of A. Bukhgeim. We then uses the range characterization of the Radon transform of functions to characterize the range of the attenuated Radon transform of vector fields as they appear in the medical diagnostic techniques of Doppler tomography. As an application we determine necessary and sufficient conditions for the Doppler and X-ray data to be mistaken for each other. We also characterize the range of real symmetric second order tensor field using the range characterization of the Radon transform of zero tensor field.
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Date Issued
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2014
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Identifier
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CFE0005408, ucf:50437
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0005408
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Title
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Placing birds on a dynamic evolutionary map: Using digital tools to update the evolutionary metaphor of the "tree of life".
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Creator
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Stephens, Sonia, Dombrowski, Paul, Applen, John, Murphy, Patrick, Lindgren, Robb, University of Central Florida
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Abstract / Description
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This dissertation describes and presents a new type of interactive visualization for communicating about evolutionary biology, the dynamic evolutionary map. This web-based tool utilizes a novel map-based metaphor to visualize evolution, rather than the traditional (")tree of life.(") The dissertation begins with an analysis of the conceptual affordances of the traditional tree of life as the dominant metaphor for evolution. Next, theories from digital media, visualization, and cognitive...
Show moreThis dissertation describes and presents a new type of interactive visualization for communicating about evolutionary biology, the dynamic evolutionary map. This web-based tool utilizes a novel map-based metaphor to visualize evolution, rather than the traditional (")tree of life.(") The dissertation begins with an analysis of the conceptual affordances of the traditional tree of life as the dominant metaphor for evolution. Next, theories from digital media, visualization, and cognitive science research are synthesized to support the assertion that digital media tools can extend the types of visual metaphors we use in science communication in order to overcome conceptual limitations of traditional metaphors. These theories are then applied to a specific problem of science communication, resulting in the dynamic evolutionary map.Metaphor is a crucial part of scientific communication, and metaphor-based scientific visualizations, models, and analogies play a profound role in shaping our ideas about the world around us. Users of the dynamic evolutionary map interact with evolution in two ways: by observing the diversification of bird orders over time and by examining the evidence for avian evolution at several places in evolutionary history. By combining these two types of interaction with a non-traditional map metaphor, evolution is framed in a novel way that supplements traditional metaphors for communicating about evolution. This reframing in turn suggests new conceptual affordances to users who are learning about evolution. Empirical testing of the dynamic evolutionary map by biology novices suggests that this approach is successful in communicating evolution differently than in existing tree-based visualization methods. Results of evaluation of the map by biology experts suggest possibilities for future enhancement and testing of this visualization that would help refine these successes. This dissertation represents an important step forward in the synthesis of scientific, design, and metaphor theory, as applied to a specific problem of science communication. The dynamic evolutionary map demonstrates that these theories can be used to guide the construction of a visualization for communicating a scientific concept in a way that is both novel and grounded in theory. There are several potential applications in the fields of informal science education, formal education, and evolutionary biology for the visualization created in this dissertation. Moreover, the approach suggested in this dissertation can potentially be extended into other areas of science and science communication. By placing birds onto the dynamic evolutionary map, this dissertation points to a way forward for visualizing science communication in the future.
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Date Issued
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2012
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Identifier
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CFE0004639, ucf:49898
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004639
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Title
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MOLECULAR TYPING OF MYCOBACTERIAL ISOLATES CULTURED FROM THE TISSUE OF INFLAMMATORY BOWEL DISEASE (CROHN'S DISEASE) PATIENTS.
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Creator
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Adams, Leanne M, Naser, Saleh, University of Central Florida
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Abstract / Description
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The role of Mycobacterium avium subsp paratuberculosis (MAP) in the etiology and pathogenesis of inflammatory bowel disease (IBD) including Crohn's Disease (CD), has been investigated. The fastidious characteristics and cross reactivity of MAP with other members in Mycobacteria have produced significant challenges in their detection and identification. In this two year pilot study, an array of three PCR molecular assays based on the detection of sequences from the16S rRNA, IS1245, and IS900...
Show moreThe role of Mycobacterium avium subsp paratuberculosis (MAP) in the etiology and pathogenesis of inflammatory bowel disease (IBD) including Crohn's Disease (CD), has been investigated. The fastidious characteristics and cross reactivity of MAP with other members in Mycobacteria have produced significant challenges in their detection and identification. In this two year pilot study, an array of three PCR molecular assays based on the detection of sequences from the16S rRNA, IS1245, and IS900 genes, belonging to members of the MAC, have been developed and optimized into a common protocol to be used as a rapid and accurate diagnostic tool regarding M. avium complex (MAC) infection. The PCR protocol time was reduced by half, and the sensitivity and specificity of the molecular assays has been significantly improved barring the need for southern hybridization. This improved methodology was employed for the molecular typing of MAC in 100 resected, full-thickness tissue samples removed from IBD patients. The tissue samples were homogenized, decontaminated, and inoculated into two mycobacterial culture media systems. A total of 328 Bactec and Mycobacteria Growth Indicator Tube (MIGT) cultures were evaluated for positive MAC growth. Harvested cells were then subjected to genomic DNA extraction and subsequent PCR typing. The I6 S rRNA-based PCR resulted in detection of 26/28 (93%) MAC in Bactec cultures. Specifically, 25/28 (89%) of positive MAC indicated the presence of IS1245 specific to M. avium subsp avium (MAV), and 6/28 (21%) produced results consistent with the presence of IS900 following nested PCR. Moreover, 20/100 (20%) of MGIT cultures were positive for MAP. Sequence analysis was performed on amplified regions of the IS900 element from seven isolates. A nucleotide alignment revealed that 2/7 isolates demonstrated 100% homology to Bovine MAP and 5/7 isolates showed 96-99% homology to sequenced Bovine MAP published in GenBank. The detection of at least two Bovine derived MAP in IBD tissue will have great impact on the epidemiology and reclassification of IBD. The significant homology of the other five isolates to Bovine derived MAP suggests a diversity in the geographical distribution of MAP regarding Johne's disease and CD. Ultimately, the etiology, diagnosis, and the treatment of IBD as well as control and prevention measures may be enhanced with better tools for investigating emerging infectious diseases.
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Date Issued
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2004
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Identifier
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CFE0000031, ucf:46125
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0000031
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Title
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PATCHWORK CULTURE: QUILT TACTICS AND DIGITEXTUALITY.
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Creator
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Barrett Ferrier, Michelle, Saper, Craig, University of Central Florida
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Abstract / Description
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Embedded in the quilt top, the fabric patches are relays, time pathways to stories and memories of their former owners. Through the quilts, the voices of the past survive. The stories trace a path of connection between oral traditions, storytelling, the invention of meaning, and the preservation of cultural memory. The theory and method described herein use the quilt patchwork metaphor as the basis for a web interface for designing and modeling knowledge-based graphical, narrative, and...
Show moreEmbedded in the quilt top, the fabric patches are relays, time pathways to stories and memories of their former owners. Through the quilts, the voices of the past survive. The stories trace a path of connection between oral traditions, storytelling, the invention of meaning, and the preservation of cultural memory. The theory and method described herein use the quilt patchwork metaphor as the basis for a web interface for designing and modeling knowledge-based graphical, narrative, and multimedia data. More specifically, the method comprises a digital storytelling and knowledge management tool that allows one or more users to create, save, store, and visually map or model digital stories. The method creates a digital network of a community's stories for digital ethnography work. Digital patches that represent the gateway to the stories of an individual are pieced together into a larger quilt design, creating a visual space that yields the voices of its creators at the click of a mouse. Through this narrative mapping, users are able to deal with complexity, ambiguity, density, and information overload. The method takes the traditional quilt use and appropriates it into a digital apparatus so that the user is connected to multiple points of view that can be dynamically tried out and compared. The hypertextual quilting method fulfills the definition of a deconstructive hypertext and emancipatory social science research methodologies by creating a collaborative, polyvocal interface where users have access to the code, content and conduits to rewrite culture's history with subaltern voices. In this digital place of intertextuality, stories are juxtaposed with images in a montage that denies the authority of a single voice and refuses fixed meaning. In dialogue, contestation, and play, the digitextuality of the Digital Story Quilt provides a praxis for critical theory. The Digital Story Quilt method concerns itself with questions of identity, the processes through which these identities are developed, the mechanics of processes of privilege and marginalization and the possibility of political action through narrative performance against these processes.
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Date Issued
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2007
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Identifier
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CFE0001659, ucf:47239
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0001659
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Title
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Improving the performance of data-intensive computing on Cloud platforms.
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Creator
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Dai, Wei, Bassiouni, Mostafa, Zou, Changchun, Wang, Jun, Lin, Mingjie, Bai, Yuanli, University of Central Florida
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Abstract / Description
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Big Data such as Terabyte and Petabyte datasets are rapidly becoming the new norm for various organizations across a wide range of industries. The widespread data-intensive computing needs have inspired innovations in parallel and distributed computing, which has been the effective way to tackle massive computing workload for decades. One significant example is MapReduce, which is a programming model for expressing distributed computations on huge datasets, and an execution framework for data...
Show moreBig Data such as Terabyte and Petabyte datasets are rapidly becoming the new norm for various organizations across a wide range of industries. The widespread data-intensive computing needs have inspired innovations in parallel and distributed computing, which has been the effective way to tackle massive computing workload for decades. One significant example is MapReduce, which is a programming model for expressing distributed computations on huge datasets, and an execution framework for data-intensive computing on commodity clusters as well. Since it was originally proposed by Google, MapReduce has become the most popular technology for data-intensive computing. While Google owns its proprietary implementation of MapReduce, an open source implementation called Hadoop has gained wide adoption in the rest of the world. The combination of Hadoop and Cloud platforms has made data-intensive computing much more accessible and affordable than ever before.This dissertation addresses the performance issue of data-intensive computing on Cloud platforms from three different aspects: task assignment, replica placement, and straggler identification. Both task assignment and replica placement are subjects closely related to load balancing, which is one of the key issues that can significantly affect the performance of parallel and distributed applications. While task assignment schemes strive to balance data processing load among cluster nodes to achieve minimum job completion time, replica placement policies aim to assign block replicas to cluster nodes according to their processing capabilities to exploit data locality to the maximum extent. Straggler identification is also one of the crucial issues data-intensive computing has to deal with, as the overall performance of parallel and distributed applications is often determined by the node with the lowest performance. The results of extensive evaluation tests confirm that the schemes/policies proposed in this dissertation can improve the performance of data-intensive applications running on Cloud platforms.
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Date Issued
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2017
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Identifier
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CFE0006731, ucf:51896
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006731
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Title
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Role of Single Nucleotide Polymorphisms (SNPs) in PTPN2/22 and Mycobacterium avium subspecies paratuberculosis (MAP) in Rheumatoid Arthritis and Crohn's Disease.
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Creator
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Sharp, Robert, Naser, Saleh, Parks, Griffith, Roy, Herve, Singla, Dinender, University of Central Florida
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Abstract / Description
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Both genetic pre-disposition and potential environmental triggers are shared between Rheumatoid arthritis (RA) and Crohn's disease (CD). We hypothesized that single nucleotide polymorphisms (SNPs) in the negative T-cell regulators Protein Tyrosine Phosphatase Non-receptor type 2 and 22 (PTPN2/22) lead to a dysregulated immune response as seen in RA and CD. To test the hypothesis, peripheral leukocytes samples from 204 consented subjects were TaqMan genotyped for 9 SNPs in PTPN2/22. The SNPs...
Show moreBoth genetic pre-disposition and potential environmental triggers are shared between Rheumatoid arthritis (RA) and Crohn's disease (CD). We hypothesized that single nucleotide polymorphisms (SNPs) in the negative T-cell regulators Protein Tyrosine Phosphatase Non-receptor type 2 and 22 (PTPN2/22) lead to a dysregulated immune response as seen in RA and CD. To test the hypothesis, peripheral leukocytes samples from 204 consented subjects were TaqMan genotyped for 9 SNPs in PTPN2/22. The SNPs effect on PTPN2/22 and IFN-y expression was determined using RT-PCR. Blood samples were analyzed for the Mycobacterium avium subspecies paratuberculosis (MAP) IS900 gene by nPCR. T-cell proliferation and response to phytohematoagglutonin (PHA) mitogen and MAP cell lysate were determined by BrdU proliferation assay. Out of 9 SNPs, SNP alleles of PTPN2:rs478582 occurred in 79% RA compared to 60% control (p-values ? 0.05). SNP alleles of PTPN22:rs2476601 occurred in 29% RA compared to 6% control (p-values ? 0.05). For the haplotype combination of PTPN2:rs478582/PTPN22rs2476601, 21.4% RA had both SNPs (C-A) compared to 2.4% control (p-values ? 0.05). PTPN2/22 expression in RA was decreased by an average of 1.2 fold. PTPN2:rs478582 upregulated IFN-y in RA by an average of 1.5 fold. Combined PTPN2:rs478582/PTPN22:rs2476601 increased T-cell proliferation by an average of 2.7 fold when treated with PHA. MAP DNA was detected in 34% RA compared to 8% controls (p-values ? 0.05), where samples with PTPN2:rs478582 and/or PTPN22:rs2476601 were more MAP positive. PTPN2:rs478582/PTPN22:rs2476601 together with MAP infection significantly increased T-cell response and IFN-y expression in RA samples. The same experimental approach was followed on blood samples from CD patients. Both PTPN2:rs478582/PTPN22:rs2476601 affected PTPN2/22 and IFN-y expression along with T-cell proliferation significantly more than in RA. MAP DNA was detected in 64% of CD. This is the first study to report the correlation between SNPs in PTPN2/22, IFN-y expression and MAP in autoimmune disease.
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Date Issued
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2018
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Identifier
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CFE0007371, ucf:52094
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007371
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Title
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An Investigation of Boaters' Attitudes toward and Usage of Targeted Mobile Apps.
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Creator
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Bowerman, Kamra, Delorme, Denise, Brown, Timothy, Neuberger, Lindsay, University of Central Florida
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Abstract / Description
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The purpose of this study was to understand boaters' adoption and usage of smartphones and mobile apps as well as to obtain their opinion on potential features of a targeted mobile app being developed as part of a broader interdisciplinary Florida Sea Grant outreach project. Data were gathered from an online survey of a sample of 164 boaters from the surrounding Central Florida area. In contrast with previous empirical mobile app studies, many respondents reported using mobile apps for...
Show moreThe purpose of this study was to understand boaters' adoption and usage of smartphones and mobile apps as well as to obtain their opinion on potential features of a targeted mobile app being developed as part of a broader interdisciplinary Florida Sea Grant outreach project. Data were gathered from an online survey of a sample of 164 boaters from the surrounding Central Florida area. In contrast with previous empirical mobile app studies, many respondents reported using mobile apps for information-seeking versus escape gratifications. Further more than half of the respondents' age sixty-five and over indicated using smartphones and mobile apps. These findings reflected recent national trend data showing shifting gratifications and an increase in technology use among older American adults. In regards to the planned mobile app, the study's respondents had favorable reactions to its potential features and indicated an above average intent toward downloading the app.
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Date Issued
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2013
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Identifier
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CFE0004655, ucf:49902
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004655
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Title
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A Hybrid Constitutive Model For Creep, Fatigue, And Creep-Fatigue Damage.
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Creator
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Stewart, Calvin, Gordon, Ali, Nicholson, David, Moslehy, Faissal, University of Central Florida
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Abstract / Description
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In the combustion zone of industrial- and aero- gas turbines, thermomechanical fatigue (TMF) is the dominant damage mechanism. Thermomechanical fatigue is a coupling of independent creep, fatigue, and oxidation damage mechanisms that interact and accelerate microstructural degradation. A mixture of intergranular cracking due to creep, transgranular cracking due to fatigue, and surface embrittlement due to oxidation is often observed in gas turbine components removed from service. The current...
Show moreIn the combustion zone of industrial- and aero- gas turbines, thermomechanical fatigue (TMF) is the dominant damage mechanism. Thermomechanical fatigue is a coupling of independent creep, fatigue, and oxidation damage mechanisms that interact and accelerate microstructural degradation. A mixture of intergranular cracking due to creep, transgranular cracking due to fatigue, and surface embrittlement due to oxidation is often observed in gas turbine components removed from service. The current maintenance scheme for gas turbines is to remove components from service when any criteria (elongation, stress-rupture, crack length, etc.) exceed the designed maximum allowable. Experimental, theoretical, and numerical analyses are performed to determine the state of the component as it relates to each criterion (a time consuming process). While calculating these metrics individually has been successful in the past, a better approach would be to develop a unified mechanical modeling that incorporates the constitutive response, microstructural degradation, and rupture of the subject material via a damage variable used to predict the cumulative (")damage state(") within a component. This would allow for a priori predictions of microstructural degradation, crack propagation/arrest, and component-level lifing. In this study, a unified mechanical model for creep-fatigue (deformation, cracking, and rupture) is proposed. It is hypothesized that damage quantification techniques can be used to develop accurate creep, fatigue, and plastic/ductile cumulative- nonlinear- damage laws within the continuum damage mechanics principle. These damage laws when coupled with appropriate constitutive equations and a degrading stiffness tensor can be used to predict the mechanical state of a component. A series of monotonic, creep, fatigue, and tensile-hold creep-fatigue tests are obtained from literature for 304 stainless steel at 600(&)deg;C (1112(&)deg;F) in an air. Cumulative- nonlinear- creep, fatigue, and a coupled creep-fatigue damage laws are developed. The individual damage variables are incorporated as an internal state variable within a novel unified viscoplasticity constitutive model (zero yield surface) and degrading stiffness tensor. These equations are implemented as a custom material model within a custom FORTRAN one-dimensional finite element code. The radial return mapping technique is used with the updated stress vector solved by Newton-Raphson iteration. A consistent tangent stiffness matrix is derived based on the inelastic strain increment. All available experimental data is compared to finite element results to determine the ability of the unified mechanical model to predict deformation, damage evolution, crack growth, and rupture under a creep-fatigue environment.
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Date Issued
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2013
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Identifier
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CFE0005061, ucf:49985
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0005061
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Title
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REAL-TIME REALISTIC RENDERING AND HIGH DYNAMIC RANGE IMAGE DISPLAY AND COMPRESSION.
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Creator
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Xu, Ruifeng, Pattanaik, Sumanta, University of Central Florida
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Abstract / Description
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This dissertation focuses on the many issues that arise from the visual rendering problem. Of primary consideration is light transport simulation, which is known to be computationally expensive. Monte Carlo methods represent a simple and general class of algorithms often used for light transport computation. Unfortunately, the images resulting from Monte Carlo approaches generally suffer from visually unacceptable noise artifacts. The result of any light transport simulation is, by its very...
Show moreThis dissertation focuses on the many issues that arise from the visual rendering problem. Of primary consideration is light transport simulation, which is known to be computationally expensive. Monte Carlo methods represent a simple and general class of algorithms often used for light transport computation. Unfortunately, the images resulting from Monte Carlo approaches generally suffer from visually unacceptable noise artifacts. The result of any light transport simulation is, by its very nature, an image of high dynamic range (HDR). This leads to the issues of the display of such images on conventional low dynamic range devices and the development of data compression algorithms to store and recover the corresponding large amounts of detail found in HDR images. This dissertation presents our contributions relevant to these issues. Our contributions to high dynamic range image processing include tone mapping and data compression algorithms. This research proposes and shows the efficacy of a novel level set based tone mapping method that preserves visual details in the display of high dynamic range images on low dynamic range display devices. The level set method is used to extract the high frequency information from HDR images. The details are then added to the range compressed low frequency information to reconstruct a visually accurate low dynamic range version of the image. Additional challenges associated with high dynamic range images include the requirements to reduce excessively large amounts of storage and transmission time. To alleviate these problems, this research presents two methods for efficient high dynamic range image data compression. One is based on the classical JPEG compression. It first converts the raw image into RGBE representation, and then sends the color base and common exponent to classical discrete cosine transform based compression and lossless compression, respectively. The other is based on the wavelet transformation. It first transforms the raw image data into the logarithmic domain, then quantizes the logarithmic data into the integer domain, and finally applies the wavelet based JPEG2000 encoder for entropy compression and bit stream truncation to meet the desired bit rate requirement. We believe that these and similar such contributions will make a wide application of high dynamic range images possible. The contributions to light transport simulation include Monte Carlo noise reduction, dynamic object rendering and complex scene rendering. Monte Carlo noise is an inescapable artifact in synthetic images rendered using stochastic algorithm. This dissertation proposes two noise reduction algorithms to obtain high quality synthetic images. The first one models the distribution of noise in the wavelet domain using a Laplacian function, and then suppresses the noise using a Bayesian method. The other extends the bilateral filtering method to reduce all types of Monte Carlo noise in a unified way. All our methods reduce Monte Carlo noise effectively. Rendering of dynamic objects adds more dimension to the expensive light transport simulation issue. This dissertation presents a pre-computation based method. It pre-computes the surface radiance for each basis lighting and animation key frame, and then renders the objects by synthesizing the pre-computed data in real-time. Realistic rendering of complex scenes is computationally expensive. This research proposes a novel 3D space subdivision method, which leads to a new rendering framework. The light is first distributed to each local region to form local light fields, which are then used to illuminate the local scenes. The method allows us to render complex scenes at interactive frame rates. Rendering has important applications in mixed reality. Consistent lighting and shadows between real scenes and virtual scenes are important features of visual integration. The dissertation proposes to render the virtual objects by irradiance rendering using live captured environmental lighting. This research also introduces a virtual shadow generation method that computes shadows cast by virtual objects to the real background. We finally conclude the dissertation by discussing a number of future directions for rendering research, and presenting our proposed approaches.
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Date Issued
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2005
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Identifier
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CFE0000730, ucf:46615
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0000730
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Title
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Semi-Analytical Solutions of Non-linear Differential Equations Arising in Science and Engineering.
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Creator
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Dewasurendra, Mangalagama, Vajravelu, Kuppalapalle, Mohapatra, Ram, Rollins, David, Kumar, Ranganathan, University of Central Florida
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Abstract / Description
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Systems of coupled non-linear differential equations arise in science and engineering are inherently nonlinear and difficult to find exact solutions. However, in the late nineties, Liao introduced Optimal Homotopy Analysis Method (OHAM), and it allows us to construct accurate approximations to the systems of coupled nonlinear differential equations.The drawback of OHAM is, we must first choose the proper auxiliary linear operator and then solve the linear higher-order deformation equation by...
Show moreSystems of coupled non-linear differential equations arise in science and engineering are inherently nonlinear and difficult to find exact solutions. However, in the late nineties, Liao introduced Optimal Homotopy Analysis Method (OHAM), and it allows us to construct accurate approximations to the systems of coupled nonlinear differential equations.The drawback of OHAM is, we must first choose the proper auxiliary linear operator and then solve the linear higher-order deformation equation by spending lots of CPU time. However, in the latest innovation of Liao's " Method of Directly Defining inverse Mapping (MDDiM)" which he introduced to solve a single nonlinear ordinary differential equation has great freedom to define the inverse linear map directly. In this way, one can solve higher order deformation equations quickly, and it is unnecessary to calculate an inverse linear operator.Our primary goal is to extend MDDiM to solve systems of coupled nonlinear ordinary differential equations. In the first chapter, we will introduce MDDiM and briefly discuss the advantages of MDDiM Over OHAM. In the second chapter, we will study a nonlinear coupled system using OHAM. Next three chapters, we will apply MDDiM to coupled non-linear systems arise in mechanical engineering to study fluid flow and heat transfer. In chapter six we will apply this novel method to study coupled non-linear systems in epidemiology to investigate how diseases spread throughout time. In the last chapter, we will discuss our conclusions and will propose some future work. Another main focus is to compare MDDiM with OHAM.
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Date Issued
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2019
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Identifier
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CFE0007624, ucf:52551
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007624
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Title
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The Performance and Power Impact of Using Multiple DRAM Address Mapping Schemes in Multicore Processors.
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Creator
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Jadaa, Rami, Heinrich, Mark, DeMara, Ronald, Yuan, Jiann-Shiun, University of Central Florida
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Abstract / Description
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Lowest-level cache misses are satisfied by the main memory through a specific address mapping scheme that is hard-coded in the memory controller. A dynamic address mapping scheme technique is investigated to provide higher performance and lower power consumption, and a method to throttle memory to meet a specific power budget. Several experiments are conducted on single and multithreaded synthetic memory traces -to study extreme cases- and validate the usability of the proposed dynamic...
Show moreLowest-level cache misses are satisfied by the main memory through a specific address mapping scheme that is hard-coded in the memory controller. A dynamic address mapping scheme technique is investigated to provide higher performance and lower power consumption, and a method to throttle memory to meet a specific power budget. Several experiments are conducted on single and multithreaded synthetic memory traces -to study extreme cases- and validate the usability of the proposed dynamic mapping scheme over the fixed one. Results show that applications' performance varies according to the mapping scheme used, and a dynamic mapping scheme achieves up to 2x increase in peak bandwidth utilization and around 30% higher energy efficiency than a system using only a single fixed scheme Moreover, the technique can be used to limit memory accesses into a subset of the memory devices by controlling data allocation at a finer granularity, providing a method to throttle main memory by allowing un-accessed devices to be put into power-down mode, hence saving power to meet a certain power budget.
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Date Issued
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2011
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Identifier
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CFE0004121, ucf:49118
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0004121
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Title
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GUIDELINES FOR TWENTY-FIRST CENTURY INSTRUCTIONAL DESIGN AND TECHNOLOGY USE: TECHNOLOGIES' INFLUENCE ON THE BRAIN.
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Creator
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Gabriel, Jennifer, Flammia, Madelyn, University of Central Florida
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Abstract / Description
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The increasingly global environment has spurred the economy in the United States as well as the economies in nearly every other nation. Although the U.S. remains the world leader in the global economy, research shows that the United States is at risk of losing its place as the world leader in science and innovation. Policymakers have recognized the need for research addressing global competitiveness. President Bush signed the America Competes Act, which calls for increased investment in...
Show moreThe increasingly global environment has spurred the economy in the United States as well as the economies in nearly every other nation. Although the U.S. remains the world leader in the global economy, research shows that the United States is at risk of losing its place as the world leader in science and innovation. Policymakers have recognized the need for research addressing global competitiveness. President Bush signed the America Competes Act, which calls for increased investment in innovation and education to improve U.S. competitiveness and President Barack Obama has named a platform, "Science, Technology and Innovation for a New Generation" which will extend and prioritize the efforts to improve math and science education. K‐12 U.S. students are graduating from high school unprepared to pursue degrees in science, technology, engineering and math (STEM) in college. Without STEM degrees they will be unable to pursue technology jobs after graduation. Statistics show that the U.S. is failing to produce as many graduates in STEM as other countries. In an increasingly global world, without graduates in STEM courses the U.S. is at risk of losing its position as the economic world leader. Government, industry and academia all agree that the U.S. needs to address education on a K‐12 level to ensure that U.S. students are equipped with twenty‐first century skills to compete in a twenty‐first century global economy. Twenty‐first century students are different from students of previous generations. Researchers argue that changes in the environment, specifically an increased exposure to technology, have changed the brains of twenty‐first century students; twenty‐first century students learn differently. However, twenty‐first century students are being taught with an instructional curriculum that was designed for a previous generation that did not have the same exposure to technology. This is causing a digital‐divide that is hindering the achievement of students. The instructional curriculum needs to be updated to meet the needs of twenty‐first century students. This thesis addresses this need from a technical communication perspective by arguing that the instructional design of twenty‐first century learning materials should be improved by adhering to guidelines for twenty‐first century learning characteristics and twenty‐first century technology use. The guidelines support a national goal to improve K‐12 achievement in order to increase U.S. STEM graduates and increase the U.S.'s ability to compete in a global economy.
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Date Issued
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2009
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Identifier
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CFE0002704, ucf:48183
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0002704
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Title
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MULTI-MODAL READING FOR LOW LEVEL READERS.
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Creator
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O'Neal, Jamie, Dombrowski, Paul, University of Central Florida
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Abstract / Description
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The value of this research hinges on the idea that exchanging illustrations for descriptive text can provide appropriate schemas for students with reading difficulties and thereby improve their comprehension and vocabulary acquisition. The research in this dissertation is based on theories and earlier research in the fields of psychology, education, reading, and narratology. A review of these fields offers a variety of perspectives on the processes involved in reading and comprehension. These...
Show moreThe value of this research hinges on the idea that exchanging illustrations for descriptive text can provide appropriate schemas for students with reading difficulties and thereby improve their comprehension and vocabulary acquisition. The research in this dissertation is based on theories and earlier research in the fields of psychology, education, reading, and narratology. A review of these fields offers a variety of perspectives on the processes involved in reading and comprehension. These processes range from the physical systems involved in reading (e.g., early childhood development, eye movement) to the psychological systems, which include cognitive load theory as well as image and text processing models. This study compares two reading methods by analyzing studentsÃÂ' vocabulary and comprehension gains. Both groups read the same text and completed the same pre- and post-tests. The control group read the text from the book which was text only. The experimental group read from a modified text on the computer screen. The text was modified by replacing some sentences with images designed to transmit the same information (e.g., descriptions of the setting, vocabulary items) in a graphic format. The images were in-line with the text, and designed to be read as part of the story, not as additional illustrations. Final analysis shows that the experimental format performed as well as the control format for most students. However, students who have learning disabilities, particularly language learners who have learning disabilities, did not make gains in the text only control format. These same students did show statistically significant gains with the experimental format, particularly the section of reading where the vocabulary words were explicitly presented in the images. Disparate, non-homogenous groupings of students reflect the actual teaching and learning circumstances in the school, as required by the school system. This situation thus represents the actual status quo situation faced by teachers in our school. We leave it to future researchers to work with more homogenous groups of students in order to attain clearer, stronger and more plaintively useful results.
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Date Issued
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2010
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Identifier
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CFE0003306, ucf:48486
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0003306
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Title
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Improvement of Data-Intensive Applications Running on Cloud Computing Clusters.
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Creator
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Ibrahim, Ibrahim, Bassiouni, Mostafa, Lin, Mingjie, Zhou, Qun, Ewetz, Rickard, Garibay, Ivan, University of Central Florida
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Abstract / Description
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MapReduce, designed by Google, is widely used as the most popular distributed programmingmodel in cloud environments. Hadoop, an open-source implementation of MapReduce, is a data management framework on large cluster of commodity machines to handle data-intensive applications. Many famous enterprises including Facebook, Twitter, and Adobehave been using Hadoop for their data-intensive processing needs. Task stragglers in MapReduce jobs dramatically impede job execution on massive datasets in...
Show moreMapReduce, designed by Google, is widely used as the most popular distributed programmingmodel in cloud environments. Hadoop, an open-source implementation of MapReduce, is a data management framework on large cluster of commodity machines to handle data-intensive applications. Many famous enterprises including Facebook, Twitter, and Adobehave been using Hadoop for their data-intensive processing needs. Task stragglers in MapReduce jobs dramatically impede job execution on massive datasets in cloud computing systems. This impedance is due to the uneven distribution of input data and computation load among cluster nodes, heterogeneous data nodes, data skew in reduce phase, resource contention situations, and network configurations. All these reasons may cause delay failure and the violation of job completion time. One of the key issues that can significantly affect the performance of cloud computing is the computation load balancing among cluster nodes. Replica placement in Hadoop distributed file system plays a significant role in data availability and the balanced utilization of clusters. In the current replica placement policy (RPP) of Hadoop distributed file system (HDFS), the replicas of data blocks cannot be evenly distributed across cluster's nodes. The current HDFS must rely on a load balancing utility for balancing the distribution of replicas, which results in extra overhead for time and resources. This dissertation addresses data load balancing problem and presents an innovative replica placement policy for HDFS. It can perfectly balance the data load among cluster's nodes. The heterogeneity of cluster nodes exacerbates the issue of computational load balancing; therefore, another replica placement algorithm has been proposed in this dissertation for heterogeneous cluster environments. The timing of identifying the straggler map task is very important for straggler mitigation in data-intensive cloud computing. To mitigate the straggler map task, Present progress and Feedback based Speculative Execution (PFSE) algorithm has been proposed in this dissertation. PFSE is a new straggler identification scheme to identify the straggler map tasks based on the feedback information received from completed tasks beside the progress of the current running task. Straggler reduce task aggravates the violation of MapReduce job completion time. Straggler reduce task is typically the result of bad data partitioning during the reduce phase. The Hash partitioner employed by Hadoop may cause intermediate data skew, which results in straggler reduce task. In this dissertation a new partitioning scheme, named Balanced Data Clusters Partitioner (BDCP), is proposed to mitigate straggler reduce tasks. BDCP is based on sampling of input data and feedback information about the current processing task. BDCP can assist in straggler mitigation during the reduce phase and minimize the job completion time in MapReduce jobs. The results of extensive experiments corroborate that the algorithms and policies proposed in this dissertation can improve the performance of data-intensive applications running on cloud platforms.
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Date Issued
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2019
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Identifier
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CFE0007818, ucf:52804
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0007818
Pages