Research On Semantic Web Rough Fuzzy Ontology And Its Application

As the knowledge base to support the actual running of semantic Web, the semantic Web imprecise ontology defines the knowledge acknowledged in a domain, and reflects the imprecise characteristics of human’s cognition about the objective world.Researches on the semantic Web imprecise ontology mainly go on along two directions of fuzziness and roughness, and the semantic Web fuzzy ontology and the semantic Web rough ontology are investigated respectively. However, human’s cognition about the objective world usually has both fuzziness and roughness, only the rough ontology or the fuzzy ontology can’t reflect the reality of human’s cognition activities completely. Therefore, as a new concept, the semantic Web rough fuzzy ontology is tried to be discussed, and its definition, model, constructing method, and application in information semantic retrieval are researched.Firstly, the meaning of the rough fuzzy concept lattice is defined. Its structure is confirmed, and the process of constructing a rough fuzzy concept lattice is put forward: introducing the lower approximation set and the upper approximation set of rough set theory into the fuzzy formal context, dividing fuzzy objects into equivalent classes, extracting rough fuzzy concepts, and constructing the rough fuzzy concept lattice.Secondly, the definition and model of the semantic Web rough fuzzy ontology are provided. Rough fuzzy concepts and relations between them are studied in detail. Composition model and description model of the semantic Web rough fuzzy ontology are put forward.Thirdly, the rough fuzzy concept lattice method of constructing the semantic Web rough fuzzy ontology is proposed. The implementation programs of converting a rough fuzzy concept lattice to a semantic Web rough fuzzy ontology is planned, that is: transforming rough fuzzy concepts into rough fuzzy classes, transforming objects into instances, transforming properties into datatype properties, transforming relations between objectives into objective properties. Based on this, the OWL representation method of the semantic Web rough fuzzy ontology is researched.Fourthly, an information semantic retrieval model based on the semantic Web rough fuzzy ontology is put forward. The semantic Web rough fuzzy ontology is applied to the information semantic retrieval, and critical steps are investigated, such as semantic annotating and indexing, retrieval request preprocessing, semantic reasoning and expanding, semantic retrieving and so on.Finally, an information semantic retrieval system based on a semantic Web rough fuzzy ontology is developed. A semantic Web rough fuzzy ontology with actual application background is constructed, and then a prototype of information semantic retrieval system is designed and implemented. The precision ratio, recall ratio and retrieval time of the prototype are tested.