Automated Composition Of Semantic Web Service Using Mediator And Complete Backward Tree

People's needs about Web applications have became diversifed,intelligent and individualized as the rapid development of Internet technology,which makes the abuse of the concomitance of manifold Webs and manifold technologies in today's Web architecture become evidence day by day. As a result,the intercommunication and amalgamation between manifold Webs have became the trends of today's Web developing.In order to conform to the trends,SOA and Web service have been proposed as solutions to compose enterprise applications.Web service is a kind of implement of software service,and its traits of self-contained and modularized make it as the best choice to implement SOA.Service is provided by more and more enterprise providers in the form of Web services as the maturating of the Web service technology.But people's needs can no more be satisfied by the atomic Web services with simple function,so,it is necessary to re-compose the existing Web services into complex business process which can meet the people's individual needs.Therefore,it is important to study how to automatically and efficiently compose the relatively simple Web services into more integrated business process which has greater functionality according to specific process logic.An approach(CBT&M_ASWSC) for composing semantic Web services automatically using mediator and complete backward tree is proposed in this paper.The idea of Mediation and backward tree are implemented in semantic Web services composition.Four main parts that this paper mainly focuses are as follows:Firstly,how to define semantics of Web services when they are concerned with composition is studied.The outstanding works in the research field about semantic Web service have been analyzed and compared in this paper,and WSDL-S is chosen to define Web services in CBT&M ASWSC approach.Because WSDL-S supports multiple domain model definition languages and to meet CBT&M_ASWSC approach's needs,OWL Ontology is used to define precise semantics of Web services' interface.Secondly,how to implement the idea of Mediator in WSMO in CBT&M_ASWSC approach to carry out the semantic transform between different Web services interfaces is studied.After clarified the motivation of using Mediator in the Web services composition problem,3 kinds of different Mediator which can be generate using ontology mapping technology and can carry out semantic transformation between 3 kinds of different objects are defined in CBT&M_ASWSC approach.Thirdly,how to integrate the strongpoints of both graph searching based approach and semantics-based approach in order to improve both the success rate and the efficiency of CBT&M_ASWSC approach is studied.A core algorithm of CBT&M_ASWSC approach named M_CBTC&OVGPS which selects the optimal valid generating path while the process of constructing the complete backward tree based on the semantic transformation provided by Mediators is proposed.M_CBTC&OVGPS embodies the advantages of CBT&M_ASWSC approach with compared to other approaches.Finally,an example which explains the implement of CBT&M ASWSC approach and an emulation experiment which validates CBT&M_ASWSC approach's feasibility and validity are presented.Our research aims to carry out an approach which can automatically compose semantic Web services,and the experimental result shows that the proposed approach improves both the success rate and the efficiency of the composition relatively.