| Ontology is defined as an explicit formal specification of a shared conceptualization. It can provide semantic meaning through relations between concepts. As a fine model for presenting hierarchy and semantic meaning of concepts, Ontology is widely concerned and extensively applied to many fields in computer science and technology, just like the Knowledge Management. Ontology originated in philosophy. Aristotle defined "Ontology" as science about "being" in the world. Since 1990s, ontology has been introduced in Artificial Intelligence, Knowledge Engineering and Library & Information sciences. And then the definition of ontology has been changed.This paper introduces the definition, the development and category of ontology. And also introduces the related theories and construction method of knowledge model. Knowledge Modeling is the abstract model of the real world, effectively organizing knowledge is an important safeguard of knowledge using. This paper compares several constructing method of knowledge model, sets up the necessity and possibility of introducing Ontology into knowledge modeling area after analyzing the current problems.According to the deficiency of current research in knowledge modeling and the superiority of expression using Ontology, this paper presents a framework of building knowledge model based on Ontology and gives a unified description and expression of three components using BNF(Backus-Naur Form)paradigm. And puts forward steps and methods of Ontology-based knowledge modeling.Then it draws an empirical study on the subsidy assignment for purchasing agricultural machinery in Guangdong province to shows the feasibility of the method. |
