Study Of Ontology-based Distributed Repository System

The notion of ontology and its technologies are introduced to CAPP (Computer Aided Process Planning) application system in this dissertation, and domain ontology repository of the system is created and part information of the repository is described by the ontology, and the repository-based intelligent information retrieval system is designed and implemented, in order to meet requirement of utmost sharing and reuse of the CAPP domain knowledge. Reference to successful experiences of the ontology in information systems such as artificial intelligence, and under the participation of domain experts, a domain ontology repository of the CAPP system is constructed at different abstract level, in which the DAML+OIL language and the editor Protégé 2000 are used to annotate syntax and semantics of concepts, their attributes and relations among concepts, and the repository is managed and maintained by hierarchical model of inverse tree. On the basis of existing four expressive styles of part information, the notion of ontology and its technologies are introduced to the repository, and ontology-based description model of part information and three-layer framework of the model is proposed in the repository, and description pattern of part feature and its structure is presented in the framework, so that a typical example indicate s part information of the repository can be expressed effectively by the description model. Acquirement and retrieval of information conveniently is one of advantages of the ontology application, namely intelligent obtains domain knowledge from distributed system. Considering some characteristic s of distributed heterogeneous repository system in the CAPP domain and the created domain ontology repository is treated as information resource, and the domain ontology repository-based intelligent information retrieval system and its architecture is presented. Consequently, the notion of ontology and its technologies, which can describe semantics of the domain information, are introduced to the intelligent information retrieval system, in which the ontology repository is became kernel component, and to some extent further improves efficiency and precision of the information search.