142,199 research outputs found

    End-to-End QoS Support for a Medical Grid Service Infrastructure

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    Quality of Service support is an important prerequisite for the adoption of Grid technologies for medical applications. The GEMSS Grid infrastructure addressed this issue by offering end-to-end QoS in the form of explicit timeliness guarantees for compute-intensive medical simulation services. Within GEMSS, parallel applications installed on clusters or other HPC hardware may be exposed as QoS-aware Grid services for which clients may dynamically negotiate QoS constraints with respect to response time and price using Service Level Agreements. The GEMSS infrastructure and middleware is based on standard Web services technology and relies on a reservation based approach to QoS coupled with application specific performance models. In this paper we present an overview of the GEMSS infrastructure, describe the available QoS and security mechanisms, and demonstrate the effectiveness of our methods with a Grid-enabled medical imaging service

    Next-Generation EU DataGrid Data Management Services

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    We describe the architecture and initial implementation of the next-generation of Grid Data Management Middleware in the EU DataGrid (EDG) project. The new architecture stems out of our experience and the users requirements gathered during the two years of running our initial set of Grid Data Management Services. All of our new services are based on the Web Service technology paradigm, very much in line with the emerging Open Grid Services Architecture (OGSA). We have modularized our components and invested a great amount of effort towards a secure, extensible and robust service, starting from the design but also using a streamlined build and testing framework. Our service components are: Replica Location Service, Replica Metadata Service, Replica Optimization Service, Replica Subscription and high-level replica management. The service security infrastructure is fully GSI-enabled, hence compatible with the existing Globus Toolkit 2-based services; moreover, it allows for fine-grained authorization mechanisms that can be adjusted depending on the service semantics.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla,Ca, USA, March 2003 8 pages, LaTeX, the file contains all LaTeX sources - figures are in the directory "figures

    Grid Enabled Geospatial Catalogue Web Service

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    Geospatial Catalogue Web Service is a vital service for sharing and interoperating volumes of distributed heterogeneous geospatial resources, such as data, services, applications, and their replicas over the web. Based on the Grid technology and the Open Geospatial Consortium (0GC) s Catalogue Service - Web Information Model, this paper proposes a new information model for Geospatial Catalogue Web Service, named as GCWS which can securely provides Grid-based publishing, managing and querying geospatial data and services, and the transparent access to the replica data and related services under the Grid environment. This information model integrates the information model of the Grid Replica Location Service (RLS)/Monitoring & Discovery Service (MDS) with the information model of OGC Catalogue Service (CSW), and refers to the geospatial data metadata standards from IS0 19115, FGDC and NASA EOS Core System and service metadata standards from IS0 191 19 to extend itself for expressing geospatial resources. Using GCWS, any valid geospatial user, who belongs to an authorized Virtual Organization (VO), can securely publish and manage geospatial resources, especially query on-demand data in the virtual community and get back it through the data-related services which provide functions such as subsetting, reformatting, reprojection etc. This work facilitates the geospatial resources sharing and interoperating under the Grid environment, and implements geospatial resources Grid enabled and Grid technologies geospatial enabled. It 2!so makes researcher to focus on science, 2nd not cn issues with computing ability, data locztic~, processir,g and management. GCWS also is a key component for workflow-based virtual geospatial data producing

    System Requirements Analysis for e-learning systems using grid

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    Until recent years network-based education and grid technologies were two distinct areas. But e-learning systems have been increasingly addressing learning resources sharing (text, images, video, on-line data, etc.) and reuse, interoperability and other more different modes of interactions. E-learning systems consist of complex activities and most of them have been designed based on client-server or peer to peer, and recently web services architecture. These systems have major drawback because of their limitations in scalability, availability, distribution of computing power and storage systems, as well as sharing information between users that contribute to these systems. In this context the use of grid technology reveals its utility and availability, as scalable, flexible coordinated and secure resource sharing among geographically distributed individuals or institutions, in the perspective of e-learning.networked-based, education, grid technologies, e-learning systems,resouce sharing, interoperability, standardisation.

    Towards ServMark, an Architecture for Testing Grid Services

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    Technical University of Delft - Technical Report ServMark-2006-002, July 2006Grid computing provides a natural way to aggregate resources from different administrative domains for building large scale distributed environments. The Web Services paradigm proposes a way by which virtual services can be seamlessly integrated into global-scale solutions to complex problems. While the usage of Grid technology ranges from academia and research to business world and production, two issues must be considered: that the promised functionality can be accurately quantified and that the performance can be evaluated based on well defined means. Without adequate functionality demonstrators, systems cannot be tuned or adequately configured, and Web services cannot be stressed adequately in production environment. Without performance evaluation systems, the system design and procurement processes are limp, and the performance of Web Services in production cannot be assessed. In this paper, we present ServMark, a carefully researched tool for Grid performance evaluation. While we acknowledge that a lot of ground must be covered to fulfill the requirements of a system for testing Grid environments, and Web (and Grid) Services, we believe that ServMark addresses the minimal set of critical issues

    The research and development of ChemGrid in CGSP

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    With the rapid development of computing technologies and network technologies, Grid technology has emerged as the solution for high-performance computing. Recently, the grid of orient-services has become a hot issue in this research area. In this paper, we propose an architecture of ChemGrid in CGSP (China Grid Support Platform). The effectiveness of the proposed architecture is demonstrated by an example which is developed as a Web service based on CGSP; the Web service is used for searching elements in the periodic table. An improvement of the user interface for applications is proposed in order to obtain results interactively. Finally, an extension of ChemGrid is discussed in order to integrate different types of resources and provide specialized services.<br /

    Architecture of the Grid Services Toolkit for Process Data Processing

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    Grid is a rapidly growing new technology that will provide easy access to huge amounts of computer resources, both hardware and software. As these resources become available soon, more and more scientific users are interested in benefiting from them. At this time the main problem accessing the Grid is that scientific users usually need big knowledge of Grid methods and technologies besides their own field of research. To fill the gap between high-level scientific Grid users and low-level functions in Grid environments the Grid Services Toolkit (GST) is developed at the IPE. Aimed to simplify and accelerate the development of parallelized scientific Grid applications, the GST is based on Web services extended by a rich client API. It is especially designed for the field of process data processing providing database access and management, common methods of statistical data analysis and project specific methods

    COLEG: Collaborative Learning Environment within Grid

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    The principal function of the CSCL environments is to provide to the various users (students, teachers, tutors…), the best activities with the best tools at the best time according to their needs. If a CSCL system is a collection of activities or learning process, we can cut out its functionalities in a certain number of autonomous functions which can then be carried out separately in the form of autonomous applications by using the technology of the Web/Grid services. The emerging technologies based on the Grid are increasingly being adopted to improve education and provide better services for learning. These services are offered to students who, regardless of their computer systems, can collaborate to improve their cognitive and social skills. This article presents COLEG (COllaborative Learning Environment within Grid), which aims to employ the capacities offered by the Grid to give the various actors, all the power of learning, collaboration and communication in an adaptable, heterogeneous and dynamic sight

    Hybrid Composition of Web Services and Grid Services

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    Abstract Web service composition is now seen as a focal point of research, especially as mechanisms for the coordination of distributed tasks are acquiring more importance. Models such as BPEL4WS can cater for local and centralised coordination. There is, however, a need to reconcile different technologies on a wider scale. This requires the development of efficient and flexible frameworks in order to ensure the optimal use and coordination of distributed applications. The work presented in this paper is concerned with the development of a compositional framework, which brings together Grid services, Web services and Semantic Web technology within a BPEL4WS platform. It is aimed at enhancing BPEL4WS by allowing for the hybrid composition of Web services and Grid services, and by incorporating dynamic binding through agent mediation. The efficient management of workflows afforded by BPEL4WS is combined with the versatility of agent technology. An agent-based system, called SOA, was developed to support the framework
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