Research And Implementation Of Ontology Based Heterogenous Data Integration Technology

With the development and application of database and network technology, massive data are stored in heterogeneous and distributed databases or files. Lots of enterprises and central office demand to integrate the distributed and heterogeneous data to realize data share. Then the heterogeneous data can be queried and analyzed by users as a unified view. Therefore, how to resolve the system heterogeneity, syntax heterogeneity and semantic heterogeneity between data sources becomes a critical research subject. However, the tranditional integration methods have difficulties to resolve the semantic heterogeneity because they can not formally describe the semantics of data. Ontology, as a formal explicit specification of a shared conceptualization, is able to represnt the knowledge of specific domain effectively. It can be used as the universal semantic model to express the semantics of heterogenous data. The thesis investigates the requirement of data integration in the Economic Operation Information Network System of National Development and Reform Commission. After analyze existing data integration technology, an ontology-based heterogeneous data integration method is put forward. The method uses Web Service to resolve the system heterogeneity and uses XML to resolve syntax heterogeneity. Further, ontology and ontology mapping technology are used to realize semantic association and resolve the semantic heterogeneity.The critical technologies of the method, including ontology construction, ontology mapping and query process are researched in the thesis。The ontology mapping technology is mainly concerned. Then a mapping discovery algorithm based on the compositive concept similarity computation is proposed. In the algorithm, similarity between concepts and properties in ontologies are computed by means of syntax distance, semantic dictionary, struct similarity and constraint computation to find the mapping relations half-automatically.At last, the thesis gives the design and impletation of the Ontology Based Data Integration System (OBDIS) with the critical technologies. It demonstrates the functions, architecture and all the modules of the system; introduces the implementation of key modules, classes and user interfaces.