关键词: 知识获取, 本体, 主题, 中文

Abstract: Acquiring knowledge from Chinese natural language documents is very difficult due to the particular characteristic of Chinese. Although many researchers have made great progress on the Chinese named entity recognition（NER for short）， it is hardly possible to extract correctly the binary relationships between a pair of recognized entities without the facilities of synonym tables， or some Chinese linguistic ontology like WordNet. Propose an ontology-theme-based method to extract these relationships from Chinese natural language documents. It is the first time to import the theme idea into domain ontology. Concepts and properties of the original domain ontology are partitioned according to the themes and the mapping relations between concepts and themes， themes and properties are established. For a sentence being processed， some entities， individuals and properties can be extracted firstly by simple NER and direct string-ontology matching. These correctly extracted information can then be used to infer the themes of this sentence. Further， the themes can provide useful clues to find more possible relationships. Results of elementary experiments indicate that this theme-based approach can obtain a higher recall rate and precision rate compared with other methods without the incorporation of theme.

Key words: knowledge acquisition, ontology, theme, Chinese