Researches On Key Techniques And Model Of Ontology-based Web Service Discovery

Recently, Web Service has developed rapidly and played an import role in the enterprise application integration. It has a lot of advantages, such as standard protocol, low coupling and platform independence. Yet, how to find the appropriate service among the massive web services, that is Web Service discovery, has become a hot topic in the area of web service research. Nowadays, Web Service discovery mainly depends on keyword- based query which finds the service by matching the service name, input, output and so on in the UDDI or WSDL. The disadvantage of this method is obvious. Because a service can not be described fully only by several key words, more over, people have different understandings of the service, Web Service discovery usually has a low recall and precision.This paper brings the concept of ontology into the field of service discovery and describes the Web Service by OWL-S ontology. Using ontology as a bridge, both service provider and service requester can describe the service clearly, which refines the match result in a semantic level.By the support of National Nature Science Fund, this paper makes some research on Web Service discovery based on ontology. First of all, the paper researches ontology construction technology and constructs a ship ontology in order to annotate Web Service by OWL-S; Second, this paper extends the UDDI register center, maps the OWL-S's Service Profile ontology into the UDDI, so as to support semantic information; Then, the paper researches ontology-based Web Service matching algorithm which adopts layered matching mechanism, that's means different algorithms are applied to different layers such as service category, service description, IO and QoS, especially improves the algorithm based on ERD in IO matching which exhibits the advantage of the ontology in Web Service discovery; at last, this paper puts forward an architecture about a Web Service discovery engine and implements a prototype to prove the feasibility of the algorithms by analysing the results of a case. This paper analyses traditional web service discovery methods, and extends the discovery mechanism by ontology in the fields of service description and service matching. These improvements could solve the problems like lower matching rate. The method and technology proposed in the paper could promote the efficiency of Web Service discovery both in theory and application.