Technology Research, Based On The Quality Of Service And The Context Of Semantic Web Service Discovery

With the emergence of Web Service, it is possible to efficiently exchange data and communicate between service providers and service requesters. However, as the Web service is used wider and wider, the Web services on the Internet become more and more, it is impractical to achieve the service discovery only by UDDI, the Semantic Web services add the semantic information to the definition of the Web Services, and help resolve this problem. Web services are augmenting daily, there are a lot of services that provide the same or similar function, but these services have non-function(QoS and Context), as, price, responsetime, user preference, cpu resources etc, and different users wish to select service according to their demand, for example, the service requester is a student, He found a number of Web services, some of the use of Web services need to pay higher fees, these Web services is not appropriate for student groups, on the contrary, while some users are more focus on reliability and high safety of the service. For this case, the semantic-based web service can not perceived users' QoS and context information, which can not to meet the growing demand of service requester. Thus, a method of QoS and Context-based semantic web service is presented.This dissertation does a research on the discovery based on QoS and Context by using of knowledge and methods of ontology, genetic algorithm etc. This paper discusses service discovery based on QoS and Context during semantic web service selection, researches how to describe QoS and Context with semantic language; how to rezlize the semantic Web service discovery based on QoS and Context; how to reduce the effect to the service selection from the fake QoSinformation and how to select the most proper service based on the special requirement from consumer and domain.First of all, a service describe model based on QoS and Context is presented. This paper reports on a study of present syntax and semantic web service describe language, the Representation Method of basic information, function interfaces, QoS and Context is studied. By improving and extending WSMO languages, to achieve the QoS and Context-based web service description.Second, a service discovery framework based on QoS and Context is achieved. Based on consulting a large number of domestic and foreign documents concerning this subject, the paper proposes a general-purpose framework for web service discovery, this framework devided the service discovery into to receive users'requests, service matching, service selection and service management etc, to support the overall QoS and Context for Web services discovery to automatically select the best.Third, this paper proposes a new method which supports QoS and Context-based web service discovery. Based on a analyze of UDDI, Semantic and P2P web service discovery, presents a 3-layer machmaker medel, and by considering the user's subjective preferences and the objectivity of QoS to achieve dynamic service selection; for the service provider may be provide a fake QoS information or service requester may be report a false QoS evaluation we have established a reputation model, which will be combined with the user and the third-party to achieve a fair and equitable.Finally, we propose a new mechanism for service optimization. Based on the knowledge and methods of ontology, genetic algorithm etc, the paper sets up two new optimizing algorithms: encode ontology concept and cluster the Web service.