Study Of The Techniques For Automated Web Service Discovery And Composition Based On Semantic

Semantic web service that is the combination of semantic web and web service,describes the function and contents of web service in a clear way, which facilitatesthe automation service discovery, execution, interoperation and composition.Cur-rently, the research of semantic web service is mainly focused on two aspects:de-scription languages that could fully describe the function, contents, attributes,inter-faces, rules and restraints of web service are understandable by heterogeneoussys-tems on the one hand, and models or architectures that effectively implementauto-matic service discovery, selection, execution, composition and interoperationbased on the description language on the other hand. Some mature descriptionlanguages are already presented in the recent research results, such as OWL-S and itsancestor DAML-S, WSML, and so on. But little progress is achieved in models orarchitec-tures about semantic web service, most of them are still at experimentalphase. This dissertation emphasizes the automatic discovery and composition ofsemantic web service, as the research orientation. The main results of the dissertationare as follows:1. A distributed and autonomic architecture of semantic web service-XUMI isproposed, which is based on OAA. Web service and service transactions are modeledusing OWL-S and XUMITask ontology in the XUMI. Automatic web servicedis-covery, service composition and service execution are effectively manipulated inthe XUMI. Besides, resource management and visual tools are also integrated in theXUMI. Flexible extensibility, easy integration and distributed autonomic architectureare inherent properties of XUMI, in contrast with traditional technologies, such asOWL-S, WSMO and METEOR-S, which is closer to the future goals of semanticweb service.2. Based on Description Logic and Dynamic Description Logic, XSDL (XUMIService Description Logics) is proposed. A unified formal framework is presented inthe XSDL, which integrates static knowledge description and dynamic reasoning in acoherent way. Using the accurate semantics, soundness and completeness of XSDL,web service transaction, service discovery, composition and execution can beeffi-ciently expressed and reasoned.3. Automatic web service discovery mechanism for XUMI is proposed, whichowns higher precision and recall compared with other web service discoverytech-nologies. A feasible service matching algorithm based on XSDL is presented, and a method that is used to quantify the service matching degree is also described.4. A reputation model for semantic web service is proposed. Compared withother web service reputation mechanisms, service reputation values in XUMI aremore efficient and accurate because semantics is contained in the service reputationto judge its authenticity and evaluations of third party are also taken into account.5. Automatic web service composition mechanism for XUMI is also proposed. Asemantic composition algorithm-SSC algorithm is described by XSDL to solve thematching problem between concrete service composition and abstract servicecomposition. To accurately verify the efficiency of service composition, an algorithmthat is used to quantify the semantic matching degree of service composition ispre-sented; three important factors that may affect semantic matching degree areconsid-ered in the algorithm: sub-service matching degree, composition structure andcon-text matching degree between different sub services.