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Description: Modern electric power systems are large and complicated, and, in many regions, the generation and transmission systems are operating near their limits. Eigenanalysis is one of the tools used to analyze the behavior of these systems. Standard eigenvalue methods require that simplified models be used for these analyses; however, these simplified models do not adequately model all of the characteristics of large power systems. Thus, new eigenanalysis methods that can analyze detailed power system models are required. The primary objectives of the work described in this report were I) to determine the availability of eigenanalysis algorithms that are better than methods currently being applied and that could be used an large power systems and 2) to determine if vector supercomputers could be used to significantly increase the size of power systems that can be analyzed by a standard power system eigenanalysis code. At the request of the Bonneville Power Administration, the Pacific Northwest Laboratory (PNL) conducted a literature review of methods currently used for the eigenanalysis of large electric power systems, as well as of general eigenanalysis algorithms that are applicable to large power systems. PNL found that a number of methods are currently being used for the this purpose, and all seem to work fairly well. Furthermore, most of the general eigenanalysis techniques that are applicable to power systems have been tried on these systems, and most seem to work fairly well. One of these techniques, a variation of the Arnoldi method, has been incorporated into a standard power system eigenanalysis package. Overall, it appears that the general purpose eigenanalysis methods are more versatile than most of the other methods that have been used for power systems eigenanalysis. In addition, they are generally easier to use. For some problems, however, it appears that some of the other eigenanalysis methods ...
Date: February 1, 1991
Creator: Elwood, D. M.
Partner: UNT Libraries Government Documents Department

Performance of a fully parallel dense real symmetric eigensolver in quantum chemistry applications

Description: The parallel performance of a dense, standard and generalized, real, symmetric eigensolver based on bisection for eigenvalues and repeated inverse iteration and reorthogonalization for eigenvectors is described. The performance of this solver, called PeIGS, is given for two test problems and for three ``real-world`` quantum chemistry applications: SCF-Hartree-Fock, density functional theory,and Moeller-Plesset theory. The distinguishing feature of the repeated inverse iteration and orthogonalization method used by PEIGS is that orthogonalization may be performed across multiple processors as dictated by the spectrum. For each problem we describe the spectrum and the clustering of the eigenvalues, the most important factor in determining the execution time. For a spectrum that is well spaced, there is essentially no orthogonalization time. Most of the time is consumed in the Householder reduction to tridiagonal form. For large clusters, almost all of the time is consumed in the Householder reduction and in orthogonalization. Performance results from the Intel Paragon, and Kendall Square Research KSR-2 are reported.
Date: April 1, 1995
Creator: Fann, G.I.; Littlefield, R.J. & Elwood, D.M.
Partner: UNT Libraries Government Documents Department

An example postclosure risk assessment using the potential Yucca Mountain Site

Description: The risk analysis described in this document was performed for the US Department of Energy`s (DOE) Office of Civilian Radioactive Waste Management (OCRWM) over a 2-year time period ending in June 1988. The objective of Pacific Northwest Laboratory`s (PNL) task was to demonstrate an integrated, though preliminary, modeling approach for estimating the postclosure risk associated with a geologic repository for the disposal of high-level nuclear waste. The modeling study used published characterization data for the proposed candidate site at Yucca Mountain, Nevada, along with existing models and computer codes available at that time. Some of the site data and conceptual models reported in the Site Characterization Plan published in December 1988, however, were not yet available at the time that PNL conducted the modeling studies.
Date: May 1, 1992
Creator: Doctor, P.G.; Eslinger, P.W.; Elwood, D.M.; Engel, D.W.; Freshley, M.D.; Liebetrau, A.M. et al.
Partner: UNT Libraries Government Documents Department