Representation And Reasoning Of Fuzzy Semantic Database Models With Description Logics

In the stage of database design, it is particularly important that how to make the semantic database models which not only have strong semantics, but also simply, clearly, and easily to be understood for users. To this end, lots of research has focused on how to realize the translation from semantic database models such as ER model and Object-Oriented data (00) model to description logics knowledge bases, so that the reasoning problems of ER model and 00 model may reason automatically through reasoning mechanism of description logics, which can contribute to constructing semantic database models exactly that meet application's needs. This is also the motivation of interrelated work. But information is often vague or ambiguous in the real-world applications. So, in order to deal with the fuzzy information, the fuzzy description logics and fuzzy semantic database models-fuzzy ER model and fuzzy Object-Oriented data model have been extensively investigated. However, less research on the fuzzy semantic database models with description logics has been done.This paper focuses on the representation and reasoning of fuzzy semantic database models (such as the fuzzy ER mode and fuzzy Object-Oriented data model) with description logics, i.e., how to translate this two kinds of models into description logics knowledge bases, and how the reasoning problems of this two kinds of models may reason automatically through the reasoning mechanism of description logics are investigated, respectively.For the ER model, the differences between the description logic ALUNI knowledge bases and DLR knowledge bases respectively translated from the ER model are investigated. Aiming at the characteristics and requirement of fuzzy ER model, the description logic DLR is generalized through fuzzy logic. A kind of new fuzzy description logic, i.e., fuzzy description logic DLR (FDLR), is presented thoroughly. The definitions of syntax structure, semantic interpretation, knowledge base form are given for the FDLR. The formal definition and semantics of fuzzy ER model are also proposed. What's more, the representation and reasoning of fuzzy ER model with the FDLR, i.e., how to translate the fuzzy ER model into the FDLR knowledge base, and how the reasoning problems of satisfiability, subsumption relation, and redundancy of fuzzy ER model may reason automatically through the reasoning mechanism of FDLR are investigated, respectively. The correctness of the translation and reasoning problems are also proved. With an example, we show that the FDLR is powerful enough to account for the essential features of fuzzy ER model.For the Object-Oriented data model, the relationship of description logic ALUNI and Object-Oriented data model is analyzed. Aiming at the characteristics and requirement of fuzzy Object-Oriented data model and based on the description logic ALUN, a kind of new fuzzy description logic fuzzy ALUN (FALUN), is presented thoroughly, although all of the constructs of which had previously been considered separately. Furthermore, a new kind of formal definition and semantics of fuzzy Object-Oriented data (FOOD) model is given. Then, The FOOD model with fuzzy description logic FALUN is investigated to translate FOOD model into FALUN knowledge bases. With an example, we can show that it is precisely such combination of constructs that makes our logic FALUN powerful enough to account for the essential features of FOOD model. The reasoning problems of FOOD model may reason automatically through reasoning mechanism of fuzzy description logic FALUN. Of course, the correctness of translation and reasoning problems are also proved.