Research Of Semantic Web Services' Search And Combination Model Based On P2P Technology

The rapid development of Internet, software forms and distributed computing, contributed to the achievement of several conceptual models, including Internetware, grid computing and cloud computing and etc. These concepts of distributed computing models are similar in concept, nevertheless, they are different.Web services is currently an mature technology in industrial application of distributed computing technology, with a series of standards, norms and protocols. The Web services technology combining the semantic Web technology produced the semantic Web services technology. The ontology describe language of semantic Web services is OWL-S, the information of Web services that described by OWL-S can be understood by computers, and computers can use these information to do rule-based deductions and proves. Two concepts that introduce semantic information to describe them can compare semantic distance between each other. If the semantic matching value between two concepts is bigger than a threshold, then the two concepts could be consider as one same concept, for they are semantic similar.A group of network technology that on the basis of peer-to-peer, including weaken the idea of central server, peers are equal all over the network and etc, could be called as P2P technology, P2P tech arises in the new century. This article simply introduces three P2P technologies based on file sharing; they are Napster, Gnutella and Chord. And the article combines the three P2P tech's characters with technologies of Web services and semantic Web, introduces a distributed computing model that mainly talked in this article.The model introduces the circle structure of Chord, and designs the structure of before-message based on the flooding thought. The model collects calling information by means of passing before-message on the network. There are two strategies of update before-message in the network:obverse and reverse. And the structure of save calling order information that during real process of calling Web services are relatively with the update strategy:stack or queue.In the process of passing before-message, the semantic match between parameter-sets happens frequent. If there are two parameter-sets A and B, that |A|>=|B|, and each parameter of set B can find a semantic similar parameter in set A, and the mapping is a injective mapping, then it can be consider that set A cover set B semantically. This article introduces a lemma based on the proposition above. Using the lemma, and combine it with some effort that other people have done, this article introduce a new formula that is more suitable with parameter-set matching of Web services. After it is an example, it could be helpful that with the example this article can analyze the model more deeply.This article designs an simulation model that based on Simulink platform. And get an result from the simulation model. According to the result, the time cost of system in acceptable, and the time cost could be reduce with a little further efforts.In the last chapter of this article, several file-sharing P2P models were compared with the model mainly talked in this article, and some flaws of the model and improving opinions are proposed.