Computing Resources (computing + resource)

Distribution by Scientific Domains

Selected Abstracts

A dynamic admission control scheme to manage contention on shared computing resources

Percival Xavier
Abstract A virtual organization is established when physical organizations collaborate to share their computing resources with the aim of serving each other when there is a likelihood of insufficient local resources during peak resource usage periods at any organization. Contention becomes a potential problem when a large number of requests, which can overwhelm the aggregate capacity of shared resources, are submitted from the participating organizations coincidentally at the same period. In particular, when a small number of requests that require large amounts of computing resources are admitted in place of a large number of requests that require less computing resources, the overall system performance, in terms of admission ratio, can deteriorate significantly. Hence, admission control is necessary to reduce resource oversubscription. Because domain-shared computing resources are likely to be combined to form a large-scale system, it is not possible to define a fixed admission policy solely based on the request's CPU and execution time requirements. In this paper, we introduce an admission control framework, based on a pricing model, for a multi-domain-shared computing infrastructure. The performance of the admission control framework is evaluated under different scenarios that contribute to the overall degree of competition for shared resources. The results are presented and analyzed in this paper. Copyright 2008 John Wiley & Sons, Ltd. [source]

GridBLAST: a Globus-based high-throughput implementation of BLAST in a Grid computing framework

Arun KrishnanArticle first published online: 24 JUN 200
Abstract Improvements in the performance of processors and networks have made it feasible to treat collections of workstations, servers, clusters and supercomputers as integrated computing resources or Grids. However, the very heterogeneity that is the strength of computational and data Grids can also make application development for such an environment extremely difficult. Application development in a Grid computing environment faces significant challenges in the form of problem granularity, latency and bandwidth issues as well as job scheduling. Currently existing Grid technologies limit the development of Grid applications to certain classes, namely, embarrassingly parallel, hierarchical parallelism, work flow and database applications. Of all these classes, embarrassingly parallel applications are the easiest to develop in a Grid computing framework. The work presented here deals with creating a Grid-enabled, high-throughput, standalone version of a bioinformatics application, BLAST, using Globus as the Grid middleware. BLAST is a sequence alignment and search technique that is embarrassingly parallel in nature and thus amenable to adaptation to a Grid environment. A detailed methodology for creating the Grid-enabled application is presented, which can be used as a template for the development of similar applications. The application has been tested on a ,mini-Grid' testbed and the results presented here show that for large problem sizes, a distributed, Grid-enabled version can help in significantly reducing execution times. Copyright 2005 John Wiley & Sons, Ltd. [source]

Supporting Bulk Synchronous Parallelism with a high-bandwidth optical interconnect

I. Gourlay
Abstract The list of applications requiring high-performance computing resources is constantly growing. The cost of inter-processor communication is critical in determining the performance of massively parallel computing systems for many of these applications. This paper considers the feasibility of a commodity processor-based system which uses a free-space optical interconnect. A novel architecture, based on this technology, is presented. Analytical and simulation results based on an implementation of BSP (Bulk Synchronous Parallelism) are presented, indicating that a significant performance enhancement, over architectures using conventional interconnect technology, is possible. Copyright 2004 John Wiley & Sons, Ltd. [source]

The ASCI Computational Grid: initial deployment

Randal Rheinheimer
Abstract Grid Services, a Department of Energy Accelerated Strategic Computing Initiative program, has designed, implemented, and deployed a grid-based solution for customer access to large computing resources at DOE weapons labs and plants. Customers can access and monitor diverse, geographically distributed resources using the common Grid Services interfaces. This paper discusses the architecture, security, and user interfaces of the Grid Services infrastructure. Published in 2002 by John Wiley & Sons, Ltd. [source]

Calculation of nonlinear aerodynamic characteristics of a wing using a 3-D panel method

Jeonghyun Cho
Abstract The nonlinear aerodynamic characteristic of a wing is investigated using the frequency-domain panel method. To calculate the nonlinear aerodynamic characteristics of a three-dimensional wing, the iterative decambering approach is introduced into the frequency-domain panel method. The decambering approach uses the known nonlinear aerodynamic characteristic of airfoil and calculates two-variable decambering function to take into consideration the boundary-layer separation effects for the each section of the wing. The multidimensional Newton iteration is used to account for the coupling between the different sections of wing. The nonlinear aerodynamic analyses for a rectangular wing, a tapered wing, and a wing with the control surface are performed. Present results are given with experiments and other numerical results. Computed results are in good agreement with other data. This method can be used for any wing having different nonlinear aerodynamic characteristics of airfoil. The present method will contribute to the analysis of aircraft in the conceptual design because the present method can predict the nonlinear aerodynamic characteristics of a wing with a few computing resources and significant time. Copyright 2007 John Wiley & Sons, Ltd. [source]

UbiXML: programmable management of ubiquitous computing resources

Dimitris Alexopoulos
XML technologies provide proven benefits for the configuration management of complex heterogeneous multi-vendor networks. These benefits have been recently manifested in numerous research, industrial and standardization efforts, including the XMLNET architecture. In this paper we present UbiXML, a system for programmable management of ubiquitous computing resources. UbiXML extends the benefits of XML technologies in the broader class of ubiquitous computing environments, which are inherently complex distributed heterogeneous and multi-vendor. In UbiXML management applications are structured as XML documents that incorporate programming constructs. Thus, UbiXML allows administrators to build sophisticated management applications with little or no programming effort. While UbiXML builds on several XMLNET concepts, it significantly augments XMLNET to handle management of sensors, perceptual components and actuating devices. Moreover, UbiXML is extensible towards additional ubiquitous computing elements. UbiXML has been exploited in implementing realistic management applications for a smart space. Copyright 2007 John Wiley & Sons, Ltd. [source]

Collaboration Online: The Example of Distributed Computing

Anne Holohan
Distributed Computing is a new form of online collaboration; such projects divide a large computational problem into small tasks that are sent out over the Internet to be completed on personal computers. Millions of people all over the world participate voluntarily in such projects, providing computing resources that would otherwise cost millions of dollars. However, Distributed Computing only works if many people participate. The technical challenge is to slice a problem into thousands of tiny pieces that can be solved independently, and then to reassemble the solutions. The social problem is how to find all those widely dispersed computers and persuade their owners to participate. This article examines what makes a collaborative Distributed Computing project successful. We report on data from a quantitative survey and a qualitative study of participants on several online forums, and discuss and analyze Distributed Computing using Arquilla and Ronfeldt's (2001) five-level network organization framework. [source]

ReSASC: A resampling-based algorithm to determine differential protein expression from spectral count data

Kristina M. Little
Abstract Label-free methods for MS/MS quantification of protein expression are becoming more prevalent as instrument sensitivity increases. Spectral counts (SCs) are commonly used, readily obtained, and increase linearly with protein abundance; however, a statistical framework has been lacking. To accommodate the highly non-normal distribution of SCs, we developed ReSASC (resampling-based significance analysis for spectral counts), which evaluates differential expression between two conditions by pooling similarly expressed proteins and sampling from this pool to create permutation-based synthetic sets of SCs for each protein. At a set confidence level and corresponding p -value cutoff, ReSASC defines a new p -value, p,, as the number of synthetic SC sets with p>pcutoff divided by the total number of sets. We have applied ReSASC to two published SC data sets and found that ReSASC compares favorably with existing methods while being easy to operate and requiring only standard computing resources. [source]