Catálogo de publicaciones - libros

In a highly mobile and active society, ubiquitous access to information and services is a general desire. The context of users is of high importance for an application to adapt automatically to changing situations and to provide the relevant data. We present a combination of space-based computing and the Semantic Web to provide a communication infrastructure that simplifies sharing data in dynamic and heterogenous systems. The infrastructure is called .

We wish to extend a warm welcome to GADA’05, The Second International Workshop on Grid Computing and its Application to Data Analysis, held in Ayia Napa (Cyprus), in conjunction with the On The Move Federated Conferences and Workshops 2005 (OTM’05).

This time around we have been fortunate enough to receive an even larger number of highly informative and engaging papers from all corners of the globe covering a wide range of scientific subjects and computational tool designs. It has been very inspiring to observe the extensive and well-formulated work being done in the development of processing and resource management tools to facilitate the ever increasing computational requirements of today’s and future projects.

The coexistence of different Grid infrastructures and the advent of Grid services based on Web Services opens an interesting debate about the coordinated harnessing of resources based on different middleware implementations and even different Grid service technologies. In this paper, we present the loosely-coupled architecture of Griday, which allows the coordinated use of different Grid infrastructures, although based on different Grid middlewares and services, as well as a straightforward resource sharing. This architecture eases the gradual migration from pre-WS Grid services to WS ones, and even, the long-term coexistence of both. We demonstrate its suitability with the evaluation of the coordinated use of two Grid infrastructures: a research testbed based on Globus WS Grid services, and a production testbed based on Globus pre-WS Grid services, as part of the LCG middleware.

Results from the DIstributed Problem SOlving (DIPSO) project are reported, which involves the implementation of a Grid-enabled Problem Solving Environment (PSE) to support conceptual design. This is a particularly important phase in engineering design, often resulting in significant savings in costs and effort at subsequent stages of design and development. Allowing a designer to explore the potential design space provides significant benefit in channelling the constraints of the problem domain into a suitable preliminary design. To achieve this, the PSE will enable the coupling of various computational components from different “Centers of Excellence”. A Web Services-based implementation is discussed. The system will support clients who have extensive knowledge of their design domain but little expertise in state-of-the-art search, exploration and optimisation techniques.

To efficiently develop and deploy parallel and distributed Grid applications, we have developed the Workflow based grId portal for problem Solving Environment(WISE). However, the Grid technology has become standardized related to Web-services for Service-oriented architecture and the workflow engine of WISE is insufficient to meet the requirements of a service-oriented environment. Therefore, we present a new workflow management system, called the Workflow management system based on Service-oriented components for Grid Applications(WSGA). It provides an efficient execution of programs for computational intensive problems using advanced patterns, dynamic resource allocation, pattern oriented resource allocation, and configures Web-service as an activity of workflow in Grid computing environment. In this paper, we propose the WSGA architecture design based on service-oriented components, and functions for using Web-services and increasing system performance. Also, we show an implementation method, and report the system performance evaluation of the WSGA architecture design.

This paper proposes a model for integrating a higher level Semantic Grid Middleware with Web Service Resource Framework (WSRF) that extends the prototype presented in [1] informed by issues that were identified in our early experiments with the prototype. WSRF defines generic and open framework for modeling and accessing stateful resources using Web Services and Web Service Notification standardizing publish/subscribe notification for Web Services. In particular we focus on using WSRF to support data integration, workflow enactment and notification management in the leading EPSRC e-Science pilot project. We report on our experience from the implementation of our proposed model and argue that our model converges with peer-to-peer technology in a promising way forward towards enabling Semantic Grid Middleware in mobile ad-hoc networks environments.

Constantly providing feedback to on-line learning teams is a challenging yet one of the latest and most attractive issues to influence learning experience in a positive manner. The possibility to enhance learning group’s participation by means of providing appropriate feedback is rapidly gaining popularity due to its great impact on group performance and outcomes. Indeed, by storing parameters of interaction such as participation behaviour and giving constant feedback of these parameters to the group may influence group’s motivation and emotional state resulting in an improvement of the collaboration. Furthermore, by feeding back to the group the results of tracking the interaction data may enhance the learners’ and groups’ problem solving abilities. In all cases, feedback implies constantly receiving information from the learners’ actions stored in log files since the history information shown is continuously updated. Therefore, in order to provide learners with effective feedback, it is necessary to process large and considerably complex event log files from group activity in a constant manner, and thus it may require computational capacity beyond that of a single computer. To that end, in this paper we show how a Grid approach can considerably decrease the time of processing group activity log files and thus allow group learners to receive selected feedback even in real time. Our approach is based on the master-worker paradigm and is implemented using Globus technology running on the Planetlab platform. To test our application, we used event log files from the Basic Support for Collaborative Work (BSCW) system.

The Open Grid Services Infrastructure (OGSI) defines a standard set of facilities which allow the creation of wide area distributed computing applications, i.e. applications which cross organisational and administrative boundaries. An earlier project demonstrated significant potential for OGSI to support mobile or remote sensors, which require the integration of devices which are wirelessly and therefore only intermittently connected to the fixed network. Further, there is significant potential for mobile clients, e.g. PDAs, to be used for data analysis. However, OGSI currently assumes the availability of a permanent network connection between client and service. This paper proposes the use of caching to provide improved access to the state of intermittently connected OGSI grid services. The paper also describes a prototype which has been implemented and tested to prove the viability of the approach.

The storing of data and configuration files related to scientific experiments is vital if those experiments are to remain reproducible, or if the data is to be shared easily. The prescence of historical (observed) data is also important in order to assist in model evaluation and development. This paper describes the design and implementation process for a data archive, which was required for a coastal modelling project.

The construction of the archive is described in detail, from its design through to deployment and testing. As we will show, the archive has been designed to tolerate failures in its communications with external services, and also to ensure that no information is lost if the archive itself fails, i.e. upon restarting, the archive will still be in exactly the same state.

A significant increase in real world event monitoring capability with wireless sensor networks brought a new challenge to ubiquitous computing. To manage high volume and faulty sensor data, it requires more sophisticated event filtering, aggregation and correlation over time and space in heterogeneous network environments. Event management will be a multi-step operation from event sources to final subscribers, combining information collected by wireless devices into higher-level information or knowledge. At the same time, the subscriber’s interest has to be efficiently propagated to event sources. We describe an event broker grid approach based on service-oriented architecture to deal with this evolution, focusing on the coordination of event filtering, aggregation and correlation function residing in event broker grids. An experimental prototype in the simulation environment with Active BAT system is presented.