Instant Service Composition And Verification Based On Fuzzy Inference

With the development of Web services technology, the number of services isincreasing more and more. But most of registered Web services on the network areservices with single function and simple structure. When faced with complex serviceneeds of users made, these simple services would appear to be powerless. So it isimportant to combine the independently existing Web services with maximumefficiency.In this paper, based on Petri net theory, we conducted in-depth research forautomatic composition of Web services and formal verification of service portfoliosequence. The main work is as follows. First, based on OWL-S Semantic Web ServiceDescription, we conducted a study of dynamic QoS extension. Then we use thecase-based reasoning (CBR) method to predict the dynamic QoS value, which hasmade service description dynamic and laid a good foundation for service discovery,service matching and service composition. Second, we use the fuzzy reasoning Petrinets (FRPN) method to conduct formal modeling of atomic processes and complexprocess which has described in OWL-S. Then with service matching ideas, weanalyzed all the dependency relationships that may occur in the service composition,and established a service release. We using reasoning methods based on fuzzyreasoning Petri nets to extracts Web service composition sequence from the servicerelease diagram by backward reasoning and forward reasoning. Third, we conductformal verification on by useing Petri net analysis techniques. On the one hand, we usethe transfer matrix analysis method to analysis the reachability of combined serviceand analysis whether there is a deadlock in combined service. On the other hand, weverify the reliability of combined service by using reachable tree analysis method.Through the above theoretical research, we conducted simulation experimentabout service dependency graph generation algorithm and service composition inference algorithm. Thus we verified the algorithm design in this article can achieveWeb services applications well, then we proved the design of model is reasonable andthe designed of algorithm is effective.