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Full-Text Articles in Physical Sciences and Mathematics

Address Optimizations For Embedded Processors, Sai Pinnepalli Jan 2004

Address Optimizations For Embedded Processors, Sai Pinnepalli

LSU Doctoral Dissertations

Embedded processors that are common in electronic devices perform a limited set of tasks compared to general-purpose processor systems. They have limited resources which have to be efficiently used. Optimal utilization of program memory needs a reduction in code size which can be achieved by eliminating unnecessary address computations i.e., generate optimal offset assignment that utilizes built-in addressing modes. Single offset assignment (SOA) solutions, used for processors with one address register; start with the access sequence of variables to determine the optimal assignment. This research uses the basic block to commutatively transform statements to alter the access sequence. Edges in …


Pattern-Based Model Transformation: A Metamodel-Based Approach To Model Evolution, Sheena Judson Miller Jan 2004

Pattern-Based Model Transformation: A Metamodel-Based Approach To Model Evolution, Sheena Judson Miller

LSU Doctoral Dissertations

Software systems continue to grow in complexity at a rapid pace, creating systems that are complex to build and evolve. The problems that accompany changes in requirements, system upgrades, and error correction produce a desire for software evolution methods that increase the efficiency and effectiveness of adapting complex software to changes. As software systems evolve, design models must be modified to accommodate the required changes. Techniques that control the changes to models in a systematic manner are a key to model evolution. A process that improves the ability to effectively modify a design, thereby enhancing design qualities, supports the need …


Machine Learning Techniques For Efficient Query Processing In Kowledge Base Systems, Kevin Paul Grant Jan 2003

Machine Learning Techniques For Efficient Query Processing In Kowledge Base Systems, Kevin Paul Grant

LSU Doctoral Dissertations

In this dissertation we propose a new technique for efficient query processing in knowledge base systems. Query processing in knowledge base systems poses strong computational challenges because of the presence of combinatorial explosion. This arises because at any point during query processing there may be too many subqueries available for further exploration. Overcoming this difficulty requires effective mechanisms for choosing from among these subqueries good subqueries for further processing. Inspired by existing works on stochastic logic programs, compositional modeling and probabilistic heuristic estimates we create a new, nondeterministic method to accomplish the task of subquery selection for query processing. Specifically, …


Control Of Transport Dynamics In Overlay Networks, Qishi Wu Jan 2003

Control Of Transport Dynamics In Overlay Networks, Qishi Wu

LSU Doctoral Dissertations

Transport control is an important factor in the performance of Internet protocols, particularly in the next generation network applications involving computational steering, interactive visualization, instrument control, and transfer of large data sets. The widely deployed Transport Control Protocol is inadequate for these tasks due to its performance drawbacks. The purpose of this dissertation is to conduct a rigorous analytical study on the design and performance of transport protocols, and systematically develop a new class of protocols to overcome the limitations of current methods. Various sources of randomness exist in network performance measurements due to the stochastic nature of network traffic. …


Computer Assisted Screening Of Digital Mammogram Images, John Terry Sample Jan 2003

Computer Assisted Screening Of Digital Mammogram Images, John Terry Sample

LSU Doctoral Dissertations

The use of computer systems to assist clinicians in digital mammography image screening has advantages over traditional methods. Computer algorithms can enhance the appearance of the images and highlight suspicious areas. Screening provides a more thorough examination of the images. Any computer system that does screening of digital mammograms contains components to address multiple tasks such as: image segmentation, mass lesion detection and classification, and microcalcification detection and classification. This dissertation provides both effective and efficient improvements to existing algorithms, which segment mammogram images and locate mass lesions. In addition, we provide a new algorithm to evaluate and report the …


Analyzing The Impact Of Changing Software Requirements: A Traceability-Based Methodology, James Steven O'Neal Jan 2003

Analyzing The Impact Of Changing Software Requirements: A Traceability-Based Methodology, James Steven O'Neal

LSU Doctoral Dissertations

Software undergoes change at all stages of the software development process. Changing requirements represent risks to the success and completion of a project. It is critical for project management to determine the impact of requirement changes in order to control the change process. We present a requirements traceability based impact analysis methodology to predictively evaluate requirement changes for software development projects. Trace-based Impact Analysis Methodology (TIAM) is a methodology utilizing the trace information, along with attributes of the work products and traces, to define a requirement change impact metric for determining the severity of a requirement change. We define the …


Level Of Essentialness Of A Node In Flowcharts And Its Application To Program Testing, Osman Kandara Jan 2003

Level Of Essentialness Of A Node In Flowcharts And Its Application To Program Testing, Osman Kandara

LSU Doctoral Dissertations

Program testing is important to develop bug free software. A common form of program testing involves selecting test cases which execute (cover) a given set W of statements in the program. In regression testing, W typically forms a small subset of the program. It is often possible to find an alternate small set W so that execution of W' implies execution of W. We develop concepts and algorithms for finding W' as small as possible with the condition that the statements in W' are "close" to those in W in terms of program structure. These concepts generalize the notion of …


Efficient Parallel Computation On Multiprocessors With Optical Interconnection Networks, Min He Jan 2002

Efficient Parallel Computation On Multiprocessors With Optical Interconnection Networks, Min He

LSU Doctoral Dissertations

This dissertation studies optical interconnection networks, their architecture, address schemes, and computation and communication capabilities. We focus on a simple but powerful optical interconnection network model - the Linear Array with Reconfigurable pipelined Bus System (LARPBS). We extend the LARPBS model to a simplified higher dimensional LAPRBS and provide a set of basic computation operations. We then study the following two groups of parallel computation problems on both one dimensional LARPBS's as well as multi-dimensional LARPBS's: parallel comparison problems, including sorting, merging, and selection; Boolean matrix multiplication, transitive closure and their applications to connected component problems. We implement an optimal …


Experience-Based Language Acquisition: A Computational Model Of Human Language Acquisition, Brian Edward Pangburn Jan 2002

Experience-Based Language Acquisition: A Computational Model Of Human Language Acquisition, Brian Edward Pangburn

LSU Doctoral Dissertations

Almost from the very beginning of the digital age, people have sought better ways to communicate with computers. This research investigates how computers might be enabled to understand natural language in a more humanlike way. Based, in part, on cognitive development in infants, we introduce an open computational framework for visual perception and grounded language acquisition called Experience-Based Language Acquisition (EBLA). EBLA can “watch” a series of short videos and acquire a simple language of nouns and verbs corresponding to the objects and object-object relations in those videos. Upon acquiring this protolanguage, EBLA can perform basic scene analysis to generate …


Fast Scalable Visualization Techniques For Interactive Billion-Particle Walkthrough, Xinlian Liu Jan 2002

Fast Scalable Visualization Techniques For Interactive Billion-Particle Walkthrough, Xinlian Liu

LSU Doctoral Dissertations

This research develops a comprehensive framework for interactive walkthrough involving one billion particles in an immersive virtual environment to enable interrogative visualization of large atomistic simulation data. As a mixture of scientific and engineering approaches, the framework is based on four key techniques: adaptive data compression based on space-filling curves, octree-based visibility and occlusion culling, predictive caching based on machine learning, and scalable data reduction based on parallel and distributed processing. In terms of parallel rendering, this system combines functional parallelism, data parallelism, and temporal parallelism to improve interactivity. The visualization framework will be applicable not only to material simulation, …


Techniques To Explore Time-Related Correlation In Large Datasets, Sumeet Dua Jan 2002

Techniques To Explore Time-Related Correlation In Large Datasets, Sumeet Dua

LSU Doctoral Dissertations

The next generation of database management and computing systems will be significantly complex with data distributed both in functionality and operation. The complexity arises, at least in part, due to data types involved and types of information request rendered by the database user. Time sequence databases are generated in many practical applications. Detecting similar sequences and subsequences within these databases is an important research area and has generated lot of interest recently. Previous studies in this area have concentrated on calculating similitude between (sub)sequences of equal sizes. The question of unequal sized (sub)sequence comparison to report similitude has been an …


Complexity And Heuristics In Ruled-Based Algorithmic Music Composition, Nigel Gwee Jan 2002

Complexity And Heuristics In Ruled-Based Algorithmic Music Composition, Nigel Gwee

LSU Doctoral Dissertations

Successful algorithmic music composition requires the efficient creation of works that reflect human preferences. In examining this key issue, we make two main contributions in this dissertation: analysis of the computational complexity of algorithmic music composition, and methods to produce music that approximates a commendable human effort. We use species counterpoint as our compositional model, wherein a set of stylistic and grammatical rules governs the search for suitable countermelodies to match a given melody. Our analysis of the complexity of rule-based music composition considers four different types of computational problems: decision, enumeration, number, and optimization. For restricted versions of the …