Research Of Domain Ontology Automatic Construction Method Based On Relational Database

With the continuous development of information, a lot of information management system has built up in the police system, and large amounts of historical data are accumulated. Currently, simple information management system has been unable to meet the application needs of the police. It has become an important problem of how to integrate many heterogeneous data sources, use data mining and provide decision support for police men. Heterogeneous data integration technology based on domain ontology can reduce semantic heterogeneous problems from many data sources by wrapping data from many data sources using domain ontology and providing a unified view for querying.System architecture of police data integration based on domain ontology is proposed on analyzing existing heterogeneous data integration technology based on domain ontology. Domain ontology automatic construction based on relational database and domain ontology integration based on concepts similarity are mainly researched in this paper. On ayalyzing existing domain ontology construction methods and the table structures of relational databases, domain ontology automatic construction method from relational databases based on rules is proposed. The experiment carried on the police's database shows that this method has higher precision to simple relational databases. Related Research shows that domain ontology integration can be done by calculating the concept similarity of domain ontology. The concept similarity of domain ontology is divided to semantic similarity an structure similarity in this paper. After ayalyzing the characteristics of local domain ontology constructed from relational databases, a formula of semantic similarity based on semantic distances in WordNet and a formula of structure similarity based on properties of ontology's concepts, which are the bases of a method of calculating concept similarity. The concept similarity calculating method makes up the problem of the un-accurate calculation about concept similarity because of non-standard naming in automatic constructed domain ontology. A domain ontology integration method is proposed based on concept similarity, which constructs global ontology by clustering concepts and analyzing clustering results.A prototype of domain ontology automatic construction system based on relational databases is established. Local ontologies about data sources in Dalian are constructed. A global ontology is generated by integrating local ontologies using domain ontology integration method based on concept similarity. Now, the ontologies have been used in data integreation system of police.