Terminal-Aware Grid Resource and Service Discovery and Access Based on Mobile Agents Technology

Mobile agents can provide a suitable framework for supporting resource and service discovery in grid platforms, and can support optimal access and interaction with the user through heterogeneous terminals, differing in terms of memory capacity, computational resources, display characteristics, allowed connection mode, etc. In this paper we deal with the utilization of Web services technology to discover and optimally access Mobile Grid resources and services, within a Mobile Agent based GriD Architecture (MAGDA) we have designed and have been implementing. Web services paradigm and SIP and UDDI technologies are utilized to implement a resource discovery service that allow users and mobile agents to look for and access distributed resources and applications, through heterogeneous terminals, by dinamically configuring the interaction session and service functionalities based on characteristic of the terminal and QoS of the interconnection

Grid-based semantic integration of heterogeneous data resources: Implementation on a HealthGrid

This thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University.The semantic integration of geographically distributed and heterogeneous data resources still remains a key challenge in Grid infrastructures. Today's mainstream Grid technologies hold the promise to meet this challenge in a systematic manner, making data applications more scalable and manageable. The thesis conducts a thorough investigation of the problem, the state of the art, and the related technologies, and proposes an Architecture for Semantic Integration of Data Sources (ASIDS) addressing the semantic heterogeneity issue. It defines a simple mechanism for the interoperability of heterogeneous data sources in order to extract or discover information regardless of their different semantics. The constituent technologies of this architecture include Globus Toolkit (GT4) and OGSA-DAI (Open Grid Service Architecture Data Integration and Access) alongside other web services technologies such as XML (Extensive Markup Language). To show this, the ASIDS architecture was implemented and tested in a realistic setting by building an exemplar application prototype on a HealthGrid (pilot implementation). The study followed an empirical research methodology and was informed by extensive literature surveys and a critical analysis of the relevant technologies and their synergies. The two literature reviews, together with the analysis of the technology background, have provided a good overview of the current Grid and HealthGrid landscape, produced some valuable taxonomies, explored new paths by integrating technologies, and more importantly illuminated the problem and guided the research process towards a promising solution. Yet the primary contribution of this research is an approach that uses contemporary Grid technologies for integrating heterogeneous data resources that have semantically different. data fields (attributes). It has been practically demonstrated (using a prototype HealthGrid) that discovery in semantically integrated distributed data sources can be feasible by using mainstream Grid technologies, which have been shown to have some Significant advantages over non-Grid based approaches

Grid-based semantic integration of heterogeneous data resources : implementation on a HealthGrid

The semantic integration of geographically distributed and heterogeneous data resources still remains a key challenge in Grid infrastructures. Today's mainstream Grid technologies hold the promise to meet this challenge in a systematic manner, making data applications more scalable and manageable. The thesis conducts a thorough investigation of the problem, the state of the art, and the related technologies, and proposes an Architecture for Semantic Integration of Data Sources (ASIDS) addressing the semantic heterogeneity issue. It defines a simple mechanism for the interoperability of heterogeneous data sources in order to extract or discover information regardless of their different semantics. The constituent technologies of this architecture include Globus Toolkit (GT4) and OGSA-DAI (Open Grid Service Architecture Data Integration and Access) alongside other web services technologies such as XML (Extensive Markup Language). To show this, the ASIDS architecture was implemented and tested in a realistic setting by building an exemplar application prototype on a HealthGrid (pilot implementation). The study followed an empirical research methodology and was informed by extensive literature surveys and a critical analysis of the relevant technologies and their synergies. The two literature reviews, together with the analysis of the technology background, have provided a good overview of the current Grid and HealthGrid landscape, produced some valuable taxonomies, explored new paths by integrating technologies, and more importantly illuminated the problem and guided the research process towards a promising solution. Yet the primary contribution of this research is an approach that uses contemporary Grid technologies for integrating heterogeneous data resources that have semantically different. data fields (attributes). It has been practically demonstrated (using a prototype HealthGrid) that discovery in semantically integrated distributed data sources can be feasible by using mainstream Grid technologies, which have been shown to have some Significant advantages over non-Grid based approaches.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Découverte de services web via le cloud computing à base d’agent mobile

Avec la rapidité de l'évolution des services Cloud, en nombre comme en fonctionnalités, le besoin d'un moteur de découverte et de composition de services devient une nécessité incontournable. Afin de réaliser un tel système, nous devons faire recours aux technologies adaptées à la nature de ce type d'applications, à savoir, les technologies d'agents et cloud computing. La technologie d'agent est très adéquate pour la modélisation des systèmes qui nécessite une collaboration entre plusieurs entités, afin de réaliser un but commun, comme la réalisation d'un système où les agents collaborent pour trouver les meilleurs services web qui correspondent aux exigences fonctionnelles et non-fonctionnelles des clients. Outre, la nature distribuée des services Cloud nous impose l’utilisation d’agents mobiles afin de chercher et créer des pistes de communications sécurisées et à moindre coût entre le moteur de recherche et les fournisseurs de services web. La technologie cloud computing, représente un atout considérable pour les applications distribuées sur internet. D'un côté cette technologie permet aux clients de payer seulement ce qu'ils utilisent comme ressources virtuelles et logicielles et leurs évite d'acheter à chaque fois la nouvelle version du système qu'ils utilisent ; d'un autre côté, cette technologie permet d'avoir un support physique et virtuel avec des capacités de stockage et de traitement illimitées. Dans notre thèse on s’est à l’étude et la proposition d’un moteur de découverte et composition qui peut accueillir et traiter des milliers de requêtes et de fichiers WSDL en même temps, et avec les meilleurs temps de réponse. Dans cette thèse nous proposant une nouvelle architecture Cloud computing basée agents pour la découverte et composition des services SaaS. Cette architecture a pour but de supporter et d'exécuter un nouveau mécanisme de sélection, composition et classification de services, ce mécanisme est basé sur une nouvelle mesure, qu'on a appelé "le degré d'existence", cette mesure nous permet de calculer le degré d'adaptation de la requête par rapport aux représentations arborescente des fichiers WSDL. De plus, ce mécanisme combine les paramètres QoS et fonctionnels pour effectuer la composition de services SaaS, ce qui permet d'avoir des services composites qui répondent aux exigences fonctionnelles et non fonctionnelles des clients. Les résultats de la simulation montrent l'efficacité du moteur de découverte et composition de services SaaS notamment en temps de réponse. L'accent est mis sur la nécessité de développer un modèle économique qui s'adapte aux fonctionnements et techniques de ce genre de moteur. Enfin, nous avons proposé un modèle de comparaison et d’évaluation afin de pouvoir comparer l’approche proposée avec les autres approches du domaine