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Virtual Organizations (virtual + organization)

Distribution by Scientific Domains

Information Science and Computing	72%

Selected Abstracts

InterGrid: a case for internetworking islands of Grids

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2008
Marcos Dias de Assunção
Abstract Over the last few years, several nations around the world have set up Grids to share resources such as computers, data, and instruments to enable collaborative science, engineering, and business applications. These Grids follow a restricted organizational model wherein a Virtual Organization (VO) is created for a specific collaboration and all interactions such as resource sharing are limited to within the VO. Therefore, dispersed Grid initiatives have led to the creation of disparate Grids with little or no interaction between them. In this paper, we propose a model that: (a) promotes interlinking of islands of Grids through peering arrangements to enable InterGrid resource sharing; (b) provides a scalable structure for Grids that allow them to interconnect with one another and grow in a sustainable way; (c) creates a global Cyberinfrastructure to support e-Science and e-Business applications. This work identifies and proposes architecture, mechanisms, and policies that allow the internetworking of Grids and allows Grids to grow in a similar manner as the Internet. We term the structure resulting from such internetworking between Grids as the InterGrid. The proposed InterGrid architecture is composed of InterGrid Gateways responsible for managing peering arrangements between Grids. We discuss the main components of the architecture and present a research agenda to enable the InterGrid vision. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Optimization of integrated Earth System Model components using Grid-enabled data management and computation

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 2 2007
A. R. Price
Abstract In this paper, we present the Grid enabled data management system that has been deployed for the Grid ENabled Integrated Earth system model (GENIE) project. The database system is an augmented version of the Geodise Database Toolbox and provides a repository for scripts, binaries and output data in the GENIE framework. By exploiting the functionality available in the Geodise toolboxes we demonstrate how the database can be employed to tune parameters of coupled GENIE Earth System Model components to improve their match with observational data. A Matlab client provides a common environment for the project Virtual Organization and allows the scripting of bespoke tuning studies that can exploit multiple heterogeneous computational resources. We present the results of a number of tuning exercises performed on GENIE model components using multi-dimensional optimization methods. In particular, we find that it is possible to successfully tune models with up to 30 free parameters using Kriging and Genetic Algorithm methods. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Supporting virtual organizations through constraint fusion

INTELLIGENT SYSTEMS IN ACCOUNTING, FINANCE & MANAGEMENT, Issue 1 2001
Alun Preece
The formation and operation of dynamic and open virtual organizations is a central concern in business-to-business e-commerce. Virtual organizations enable partner companies to develop and manufacture customized products with low costs and rapid delivery. Agent-based architectures are an effective platform for such virtual organizations because they provide mechanisms to allow organizations to advertise their capabilities, exchange rich information, and synchronize workflows at a high level of abstraction. In this paper, we examine the KRAFT architecture and its features for supporting virtual organizations. In particular, we focus upon KRAFT's agent-based architecture, and its use of constraints as a knowledge-exchange medium. We show how constraint fusion supports the design of customized products. © 2001 John Wiley & Sons, Ltd. [source]

Cross-domain authorization for federated virtual organizations using the myVocs collaboration environment

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 4 2009
Jill Gemmill
Abstract This paper describes our experiences building and working with the reference implementation of myVocs (my Virtual Organization Collaboration System). myVocs provides a flexible environment for exploring new approaches to security, application development, and access control built from Internet services without a central identity repository. The myVocs framework enables virtual organization (VO) self-management across unrelated security domains for multiple, unrelated VOs. By leveraging the emerging distributed identity management infrastructure. myVocs provides an accessible, secure collaborative environment using standards for federated identity management and open-source software developed through the National Science Foundation Middleware Initiative. The Shibboleth software, an early implementation of the Organization for the Advancement of Structured Information Standards Security Assertion Markup Language standard for browser single sign-on, provides the middleware needed to assert identity and attributes across domains so that access control decisions can be determined at each resource based on local policy. The eduPerson object class for lightweight directory access protocol (LDAP) provides standardized naming, format, and semantics for a global identifier. We have found that a Shibboleth deployment supporting VOs requires the addition of a new VO service component allowing VOs to manage their own membership and control access to their distributed resources. The myVocs system can be integrated with Grid authentication and authorization using GridShib. Copyright © 2008 John Wiley & Sons, Ltd. [source]

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

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 2 2009
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]

Formation of virtual organizations in grids: a game-theoretic approach

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 14 2010
Thomas E. Carroll
Abstract Applications require the composition of resources to execute in a grid computing environment. The grid service providers (GSPs), the owners of the computational resources, must form virtual organizations (VOs) to be able to provide the composite resource. We consider grids as self-organizing systems composed of autonomous, self-interested GSPs that will organize themselves into VOs with every GSP having the objective of maximizing its profit. Using game theory, we formulate the resource composition among GSPs as a coalition formation problem and propose a framework to model and solve it. Using this framework, we propose a resource management system that supports the VO formation among GSPs in a grid computing system. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Cross-domain authorization for federated virtual organizations using the myVocs collaboration environment

The Grid Resource Broker workflow engine

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 15 2008
M. Cafaro
Abstract Increasingly, complex scientific applications are structured in terms of workflows. These applications are usually computationally and/or data intensive and thus are well suited for execution in grid environments. Distributed, geographically spread computing and storage resources are made available to scientists belonging to virtual organizations sharing resources across multiple administrative domains through established service-level agreements. Grids provide an unprecedented opportunity for distributed workflow execution; indeed, many applications are well beyond the capabilities of a single computer, and partitioning the overall computation on different components whose execution may benefit from runs on different architectures could provide better performances. In this paper we describe the design and implementation of the Grid Resource Broker (GRB) workflow engine. Copyright © 2008 John Wiley & Sons, Ltd. [source]

The development of a geospatial data Grid by integrating OGC Web services with Globus-based Grid technology

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 14 2008
Liping Di
Abstract Geospatial science is the science and art of acquiring, archiving, manipulating, analyzing, communicating, modeling with, and utilizing spatially explicit data for understanding physical, chemical, biological, and social systems on the Earth's surface or near the surface. In order to share distributed geospatial resources and facilitate the interoperability, the Open Geospatial Consortium (OGC), an industry,government,academia consortium, has developed a set of widely accepted Web-based interoperability standards and protocols. Grid is the technology enabling resource sharing and coordinated problem solving in dynamic, multi-institutional virtual organizations. Geospatial Grid is an extension and application of Grid technology in the geospatial discipline. This paper discusses problems associated with directly using Globus-based Grid technology in the geospatial disciplines, the needs for geospatial Grids, and the features of geospatial Grids. Then, the paper presents a research project that develops and deploys a geospatial Grid through integrating Web-based geospatial interoperability standards and technology developed by OGC with Globus-based Grid technology. The geospatial Grid technology developed by this project makes the interoperable, personalized, on-demand data access and services a reality at large geospatial data archives. Such a technology can significantly reduce problems associated with archiving, manipulating, analyzing, and utilizing large volumes of geospatial data at distributed locations. Copyright © 2008 John Wiley & Sons, Ltd. [source]

GOLD infrastructure for virtual organizations

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 11 2008
P. Periorellis
Abstract The paper discusses the GOLD project (Grid-based Information Models to Support the Rapid Innovation of New High Value-Added Chemicals) whose principal aim is to carry out research and development into enabling technologies to support the formation, operation and termination of virtual organizations. The paper discusses the outcome of this research, which is the GOLD Middleware infrastructure. The infrastructure has been implemented in the form of a set of Middleware components, which address issues such as trust, security, contract monitoring and enforcement, information management and coordination. We discuss all these issues in turn and more importantly we demonstrate how current WS standards can be used to implement these issues. In addition, the paper follows a top down approach starting with a brief outline on the architectural elements derived during the requirements engineering phase and demonstrates how these elements were mapped onto actual services that were implemented according to service-oriented architecture principles and related technologies. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Job completion prediction using case-based reasoning for Grid computing environments

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 9 2007
Lilian Noronha Nassif
Abstract One of the main focuses of Grid computing is solving resource-sharing problems in multi-institutional virtual organizations. In such heterogeneous and distributed environments, selecting the best resource to run a job is a complex task. The solutions currently employed still present numerous challenges and one of them is how to let users know when a job will finish. Consequently, reserve in advance remains unavailable. This article presents a new approach, which makes predictions for job execution time in Grid by applying the case-based reasoning paradigm. The work includes the development of a new case retrieval algorithm involving relevance sequence and similarity degree calculations. The prediction model is part of a multi-agent system that selects the best resource of a computational Grid to run a job. Agents representing candidate resources for job execution make predictions in a distributed and parallel manner. The technique presented here can be used in Grid environments at operation time to assist users with batch job submissions. Experimental results validate the prediction accuracy of the proposed mechanisms, and the performance of our case retrieval algorithm. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Trust, commitment and team working: the paradox of virtual organizations

GLOBAL NETWORKS, Issue 4 2004
Alf Crossman
The findings of a case study in an international information technology consultancy indicate that multiple relationships arising from the alliance-based structure require clear commitment to enable the development of trust as a basis for longer-term partnership. Paradoxically, the perceived low level of commitment from the organization does not engender the high level of trust and commitment required from virtual teams to maximize their performance. However, over time and with extended exchanges, the commitment level and form may evolve, thus necessitating a realignment of existing psychological understanding and trust between the actors. If there is general agreement that an upward shift from short-term to long-term commitment is beneficial to all, then the virtual arrangement will continue to be effective. [source]

Supporting virtual organizations through constraint fusion

Economics-inspired decentralized control approach for adaptive grid services and applications

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 12 2006
Lei Gao
Grid technologies facilitate innovative applications among dynamic virtual organizations, while the ability to deploy, manage, and properly remain functioning via traditional approaches has been exceeded by the complexity of the next generation of grid systems. An important method for addressing this challenge may require nature-inspired computing paradigms. This technique will entail construction of a bottom-up multiagent system; however, the appropriate implementation mechanism is under consideration in order for the autonomous and distributed agents to emerge as a controlled grid service or application. A credit card management service in economic interactions is considered in this article for a decentralized control approach. This consideration is based on a preliminarily developed ecological network-based grid middleware that has features desired for the next generation grid systems. The control scheme, design, and implementation of the credit card management service are presented in detail. The simulation results show that (1) agents are accountable for their activities such as behavior invocation, service provision, and resource utilization and (2) generated services or applications adapt well to dynamically changing environments such as agent amounts as well as partial failure of agents. The approach presented herein is beneficial for building autonomous and adaptive grid applications and services. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 1269,1288, 2006. [source]