A Framework of Extracting Sub-ontology

It often needs to extract sub-ontology from large-scale ontology for application. Current approaches mainly focus on extraction in single ontology. However, an application may require several large-scale ontologies in different domains; it needs approaches of extracting sub-ontology from multiple ontologies. This paper proposes a framework of extracting sub-ontology from multiple ontologies. In the framework, a unified visualized ontology model is proposed; different Ontology language codes are translated into the unified model firstly. Then we divide the user requirements to extract sub-ontology from each ontology; the extraction is in an iterative and incremental process. Finally, we integrate these sub-ontologies into the sub-ontology that the user demands, and translate the result back to the Ontology language the user uses. This framework avoids doing integration and extraction processes with large-scale ontologies, which are the most difficult processes in current approaches.