Research Of Semantic Web Services Composition Based On Dynamic Logic

With the rapid development of Web service technologies, more and more Webservices are running on the Internet. However, a single Web Service’s function islimited, which make it difficult to meet the growing and changing user need.Therefore how to compose the Web services of heterogeneous plantforms to providethe user with a more powerful and valuable function has becomes a hot topic ofResearch in the field of Web Service. Currently, many research institutions at homeor abroad begin to sudy the Web services composition and achieved some success.However, there are still some problems need to solve. For example, how todetermine the logic and timing relationship between the basic Web services so thatcomplex Web services can be composed automatically; how to test and validate Webservices composition so that the result of executon of Web services is correct.Aiming at these problems, this paper proposed an automatic semantic Web servicecompostion method based on dynamic logic. Semantic Web services are mappe to theaction and formula of the dynamic logic and the Web services compositon can beachieved by the reasoning of dynamic logic. The advantages of this method lie in theautomation of Web services compositon and correctness of the result of Web servicescompositon.The main job of this paper includes:1. The OWL-S Process Model of semantic Web services will be formalized byaction and formula of dynamic logic. This method allows for formalizing atomicprocesses with their local variables, variable bindings, input, outputs, preconditionsand results. It also offer considerable expressive power for describing the controlstructures of composition such as the sequence, If-Then-Else, Choice, Repeat and soon.2. In the process of carrying out Web services compostion, the Web servicescompositon problem is treated as the planning problem of dynamic logic. The inputsof a user are represented as the intial state of the planning, the outputs of Webservices are represented as the goal of the planning. Web services compositon isgenerated by search a planning from an intial state to a goal state. Because theplanning is achieved by reasoning of dynamic logic, the automation of Web servicescompositon and correctness of the result of Web services compositon can be ensured. 3. The dynamic logic based semantic Web services composition architecture isgiven to implement the atuomatic service composition. The framework is dividedinto the user layer, semantic layer and execution layer. The user layer comprises theOntology-driven graphical user interface module. The semantic layer is composed ofthe OWL-S semantic descriptionos module, the dynamic logic tranlator module, thedynamic logic knowledge base module and the composition engine module. TheExecution layer is composed of execution engine module and execution resultmodule.