摘要 : Ontologies, such as UMLS and WordNet, are generally very large, and are normally the source of more specialised and smaller ontologies tailored for a certain application. It is natural that the source ontologies be multiple large ... 展开 Ontologies, such as UMLS and WordNet, are generally very large, and are normally the source of more specialised and smaller ontologies tailored for a certain application. It is natural that the source ontologies be multiple large ontologies, each of which is extracted, and then merged to create a smaller and tailored ontology for a specific domain. Therefore, extracting sub-ontologies as well as merging them is a primary process. In this paper, we propose sub-ontology extraction and merging, whereby multiple sub-ontologies are extracted from various source ontologies and then these extracted sub-ontologies are merged to form a complete ontology to be used by the user. We use the maximum extraction method to facilitate this. A walkthrough case study using the UMLS meta-thesaurus ontology is also presented. 收起