The emerging decentralized virtual organizations provide various environments for the collaborative work performed by the users distributed in terms of geography and time. In such virtual organizations, hypermedia documents should be observed and controlled to suit each organization's needs. We discuss the mechanisms in which environments of virtual organizations control views of shared hyperme...

In this document we describe our work-in-progress for enabling fine-grain authorization of resource management. In particular we address the needs of Virtual Organizations (VOs) to enforce their own polices in addition to those of the resource owners.

This paper introduces the concept of the virtual workspace, a configurable execution environment that can be used to describe, dynamically deploy, and manage a customizable execution environment in the Grid. We describe workspaces, show how they fit into the Grid architecture, and discuss our initial experiences using this system with applications.

We describe how the Grid enables new research possibilities in astronomy through multiwavelength images. To see sky images in the same pixel space, they must be projected to that space, a compute-intensive process. There is thus a virtual data space induced that is defined by an image and the applied projection. This virtual data can be created and replicated with Planners and Replica catalog t...

This paper presents the work performed for the implementation of the geospatial product virtualization in the Grid environment. A virtual geospatial product is a product that does not exist in a geospatial data system but the system knows how to create such a product when a user requests the product. We use a two-step approach to the implementation. The first step is to represent a virtual geos...

The main feature of the Grid, which appeals to communities outside of the high performance computing community, is its ability to share resources across boundaries of institutions and organizations, or in other words, resources that are not subject to centralized control [1]. In computational grids, the shared resource is computing power of processors, thus a computational grid forms a large vi...

Research on Grids has received considerable attention in recent years. Whereas existing work on connecting the grids primarily focused on grid services, in our work we propose a unified approach, so-called FederationGrid (or FedGrid for short), which integrates both virtual organization (VO) and grid services, thus enabling formation of virtual communities on top of grids. FedGrid is based on t...

A Grid system is a Virtual Organization that is composed of several autonomous domains .It concerned with the sharing and coordinated use of diverse resources in distributed "virtual organizations.” The dynamic and multiinstitutional nature of these environments introduces challenging security issues that demand new technical approaches. In particular, one must deal with diverse local mechanism...