Method for Extracting RDF(S) Sub-Ontology

RDF ontology can represent semantic information in semantic Web. Ontologies are often too large to be used in a single application. Extracting sub-ontology from large-scale ontology can solve this problem. RDF(S) ontologies are abstracted as graph models. According to the RDFS inference rules, the closure of RDFS ontology graph model can be constructed. To decrease the time of generating closure, a parallel closure algorithm is presented. We also present an algorithm based on the graph theory to extract a sub-graph with the concepts in the domain term lexicon as nodes. This sub-graph is regarded as the required domain ontology. The method is applicable to RDF(S) domain ontology extraction. Applying the method, domain ontology can be built fast and effectively.