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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Multi-Image Classification And Compression Using Vector Quantization, Beverly J. Thompson
Multi-Image Classification And Compression Using Vector Quantization, Beverly J. Thompson
Dissertations, Theses, and Masters Projects
Vector Quantization (VQ) is an image processing technique based on statistical clustering, and designed originally for image compression. In this dissertation, several methods for multi-image classification and compression based on a VQ design are presented. It is demonstrated that VQ can perform joint multi-image classification and compression by associating a class identifier with each multi-spectral signature codevector. We extend the Weighted Bayes Risk VQ (WBRVQ) method, previously used for single-component images, that explicitly incorporates a Bayes risk component into the distortion measure used in the VQ quantizer design and thereby permits a flexible trade-off between classification and compression priorities. In …
Accurate Visualization Of Distributed System Execution, Dennis Lee Edwards
Accurate Visualization Of Distributed System Execution, Dennis Lee Edwards
Dissertations, Theses, and Masters Projects
The concurrent execution of processes in a distributed system makes the interactions between them difficult to understand. A clear image of the execution sequence that occurs as well as possible alternative scenarios is paramount to providing the software engineer the understanding needed to create reliable software.;In this thesis, we examine several representation methods of presenting a pictorial view of the execution of a distributed system and evaluate each in terms of three criteria. First, only those relationships that are created during the execution can and must be presented. Second, the presentation must be such that a reasonable amount of information …
Artificial Societies: A Computational Model Of Disease Transmission, Nathan T. Moore
Artificial Societies: A Computational Model Of Disease Transmission, Nathan T. Moore
Dissertations, Theses, and Masters Projects
No abstract provided.
Limits To Parallelism In Scientific Computing, Dan Alvin Chrisman Jr.
Limits To Parallelism In Scientific Computing, Dan Alvin Chrisman Jr.
Dissertations, Theses, and Masters Projects
The goal of our research is to decrease the execution time of scientific computing applications. We exploit the application's inherent parallelism to achieve this goal. This exploitation is expensive as we analyze sequential applications and port them to parallel computers. Many scientifically computational problems appear to have considerable exploitable parallelism; however, upon implementing a parallel solution on a parallel computer, limits to the parallelism are encountered. Unfortunately, many of these limits are characteristic of a specific parallel computer. This thesis explores these limits.;We study the feasibility of exploiting the inherent parallelism of four NASA scientific computing applications. We use simple …
Artificial Societies: A Computational Approach To Studying Combat, Rachel J. Moore
Artificial Societies: A Computational Approach To Studying Combat, Rachel J. Moore
Dissertations, Theses, and Masters Projects
No abstract provided.
Causal Distributed Assert Statements, Sharon J. Simmons
Causal Distributed Assert Statements, Sharon J. Simmons
Dissertations, Theses, and Masters Projects
Monitoring a program's execution is fundamental to the debugging, testing and maintenance phases of program development. This research addresses the issue of monitoring the execution of a distributed program. In particular, we are concerned with efficient techniques for evaluating global state predicates for distributed programs. The global state of a distributed program is not well-defined, making the monitoring task complex compared to that of a sequential programs. Processes of a distributed program execute concurrently, and the events of the program cannot be totally ordered. Each process has its own local memory, and the local memories are physically separate.;Despite the difficulties …
Dynamic Load Balancing Via Thread Migration, David Cronk
Dynamic Load Balancing Via Thread Migration, David Cronk
Dissertations, Theses, and Masters Projects
Light-weight threads are becoming increasingly useful for parallel processing. This is particularly true for threads running in a distributed memory environment. Light-weight threads can be used to support latency hiding techniques, communication and computation overlap, and functional parallelism. Additionally, dynamic migration of light-weight threads supports both data locality and load balancing. Designing a thread migration mechanism presents some very unique and interesting challenges. One such challenge is maintaining communication between mobile threads. A potentially more difficult challenge involves maintaining the correctness of pointers within mobile threads. Since traditional pointers have no concept of address space, moving threads from processor to …