Research On Web Service Composition Based On Function Ontology And QoS

Although traditional Web service composition technologies can achieve the combination between the services, the description files of service component lack the semantic information understood by computer so that the flexibility of service composition process and the correctness of the combined services are limited. With the rapid development of the semantic Web technology, many researchers introduce it into Web service automatic composition followed by forming semantic Web service. Semantic Web service embodies the thought of semantic Web applied to the service-oriented computing(SOC) as well as it contains semantic information understood by the computer by the means of the combination between Web service and semantic Web service. This makes the automatic discovery and automatic composition among the Web services come true.Recently, Semantic Web service is a hot research topic in academia that contains two main purposes:(1) improve the speed and accuracy of the automatic composition among the semantic Web services.(2) improve the quality of the service composition scheme in order to meet the needs of users and make the run quality ideal. To address above problems, firstly, this paper proposed a service discovery mechanism based on functions which add the functional description information to the semantic Web service description. Secondly, the harmony search algorithm was introduced to select the specific services so that the composition service can meet the users' requirements. Finally, the experiments showed the effectiveness of the proposed methods. The main innovation of this paper is as follows:(1) Study on the Web service composition based on functions. It achieves by making Web service functional description model and domain functional ontology. Besides, its detailed implementation shows in the OWL-S and this paper gives the detailed procedure to discover service according to the users' functional requirements. The proposed method can achieve the service composition based on functions, filter unrelated services, reduce calculation amount and improve the efficiency for service discovery.(2) Introduce the harmony search algorithm to service selection. Firstly, this paper describes the theoretical feasibility about applying the algorithm to service selection. Secondly, this paper modifies harmony algorithm which is more appropriate to the service selection and lists the pseudo-code.(3) Build prototype system to verify the accuracy of service discovery based on domain functional ontology and the advantage of the harmony search algorithm applied to service selection. The accuracy and feasibility of thought proposed in this paper is showed by the comparison between modified harmony search algorithm and the other heuristic search algorithm.