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Parallel Systems (parallel + system)

Distribution by Scientific Domains

Mathematics and Statistics	55%

Selected Abstracts

ON THE CHANGE POINT OF THE MEAN RESIDUAL LIFE OF SERIES AND PARALLEL SYSTEMS

AUSTRALIAN & NEW ZEALAND JOURNAL OF STATISTICS, Issue 1 2010
Yan Shen
Summary This paper considers the mean residual life in series and parallel systems with independent and identically distributed components and obtains relationships between the change points of the mean residual life of systems and that of their components. Compared with the change point for single components, should it exists, the change point for a series system occurs later. For a parallel system, however, the change point is located before that for the components, if it exists at all. Moreover, for both types of systems, the distance between the change points of the mean residual life for systems and for components increases with the number of components. These results are helpful in the determination of optimal burn-in time and related decision making in reliability analysis. [source]

Parallel heterogeneous CBIR system for efficient hyperspectral image retrieval using spectral mixture analysis

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 9 2010
Antonio J. Plaza
Abstract The purpose of content-based image retrieval (CBIR) is to retrieve, from real data stored in a database, information that is relevant to a query. In remote sensing applications, the wealth of spectral information provided by latest-generation (hyperspectral) instruments has quickly introduced the need for parallel CBIR systems able to effectively retrieve features of interest from ever-growing data archives. To address this need, this paper develops a new parallel CBIR system that has been specifically designed to be run on heterogeneous networks of computers (HNOCs). These platforms have soon become a standard computing architecture in remote sensing missions due to the distributed nature of data repositories. The proposed heterogeneous system first extracts an image feature vector able to characterize image content with sub-pixel precision using spectral mixture analysis concepts, and then uses the obtained feature as a search reference. The system is validated using a complex hyperspectral image database, and implemented on several networks of workstations and a Beowulf cluster at NASA's Goddard Space Flight Center. Our experimental results indicate that the proposed parallel system can efficiently retrieve hyperspectral images from complex image databases by efficiently adapting to the underlying parallel platform on which it is run, regardless of the heterogeneity in the compute nodes and communication links that form such parallel platform. Copyright © 2009 John Wiley & Sons, Ltd. [source]

ON THE CHANGE POINT OF THE MEAN RESIDUAL LIFE OF SERIES AND PARALLEL SYSTEMS

Workload decomposition strategies for hierarchical distributed-shared memory parallel systems and their implementation with integration of high-level parallel languages

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 11 2002
Sergio Briguglio
Abstract In this paper we address the issue of workload decomposition in programming hierarchical distributed-shared memory parallel systems. The workload decomposition we have devised consists of a two-stage procedure: a higher-level decomposition among the computational nodes; and a lower-level one among the processors of each computational node. By focusing on porting of a case study particle-in-cell application, we have implemented the described work decomposition without large programming effort by using and integrating the high-level language extensions High-Performance Fortran and OpenMP. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Scottish Higher Education and the FE-HE Nexus

HIGHER EDUCATION QUARTERLY, Issue 4 2003
Brenda Morgan-Klein
Over half of Scottish higher education entrants in 2000/01 began their studies in further education. This reflects the growing diversity of higher education in Scotland as a result of institutional change and trends in policy and practice. While these changes have been constructed positively as contributing to the accessibility of Scottish higher education, clear differences between HE provision in the two sectors and sectoral differentiation in patterns of participation have given rise to two relatively disconnected systems of higher education. The emergence of parallel systems may conceal new patterns of inequality, giving rise to a new learning divide. [source]

Block s-step Krylov iterative methods

NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 1 2010
Anthony T. Chronopoulos
Abstract Block (including s-step) iterative methods for (non)symmetric linear systems have been studied and implemented in the past. In this article we present a (combined) block s-step Krylov iterative method for nonsymmetric linear systems. We then consider the problem of applying any block iterative method to solve a linear system with one right-hand side using many linearly independent initial residual vectors. We present a new algorithm which combines the many solutions obtained (by any block iterative method) into a single solution to the linear system. This approach of using block methods in order to increase the parallelism of Krylov methods is very useful in parallel systems. We implemented the new method on a parallel computer and we ran tests to validate the accuracy and the performance of the proposed methods. It is expected that the block s-step methods performance will scale well on other parallel systems because of their efficient use of memory hierarchies and their reduction of the number of global communication operations over the standard methods. Copyright © 2009 John Wiley & Sons, Ltd. [source]