Research Of Semantic Service Discovery Based On Fuzzy Logic

With the development of network technology, computing presents its mobile and pervasive characters. In the dynamic and Theterogeneous T network environment, finding the appropriate service is an important premise for information share and reuse. The traditional service discovery protocol on the syntax level cannot satisfy people's intelligent and individual demands in recall and precision aspects. To solve these problems, computing entities need to understand and process information in the network, which is the support of service discovery on the"semantic"level. Currently, the research of semantic service discovery is in the exploration phase, especially the uncertain information service discovery with no mature theory and technology. This thesis performs deep research in the semantic service discovery with vague knowledge based on fuzzy logic theory, which focuses on the two key problems: semantic service description and semantic service matchmaking, and gets some results below:1. SHOIN-f is proposed to describe the fuzzy extension of description logic SHOIN and is treated as the formal basis of knowledge representation. Fuzzy composition relationship, fuzzy quantity, fuzzy modifier and fuzzy linguistic value are introduced into SHOIN to increase description logic's representing and deducing ability of fuzzy information. Compared with other fuzzy description logics, SHOIN-f not only extends the semantics, but also extends the syntax of the description logic. The syntax extension enriches constructors of the describe logic, and founds logical basis for service description.2. The service description language FEOWL is proposed based on ontology. Because ontology languages possess strong deduction and ratiocination ability, currently, adopting ontology to represent services'semantic information is one of the best solutions. Ontology language FEOWL is a fuzzy extension of OWL DL based on SHOIN-f and allows OWL DL to possess representing and processing ability in class, property, individual, and axiom aspects.3. The service discovery architecture and service description model are proposed. The architecture regards the services as two different degrees of abstract through service ontology, corresponding to abstract service level and concrete service level. This design is good to category and organization of service, and increases the service discovery efficiency. Based on this architecture, a service description model based on ontology language FEOWL is proposed to describe the two aspects of services, those are service capability information and fuzzy information.4."2-stage plus 2-level"service matchmaking strategy and method are proposed. Based on service model, the services are divided to two stage filterings (service category filtering and service area filtering), two level matchmakings (service capability matchmaking and fuzzy matchmaking). The results from service matchmaking are natural languages, which presents the matchmaking degree. This elastic multi level service matchmaking with filtering mechanism helps users to make choice and decision, increases the service discovery's efficiency, recall and precision.The research introduces the fuzzy theory into service discovery, allows the result of service discovery tally with the practical reality and presents theory and practical meaning of researches in logical service description and knowledge ratiocination.