本体是人对客观事物及其相互关系的认知成果,表现形式为概念及概念关系,二者均以语词称之。人只能自如应用有限的语词,致使人的认知有两个必备特征:一个语词指称多个概念,即以变动概念外延的方式减少概念的数量;一个语词指称多个概念关系,即以隶属度的形式归并概念关系的种类。前者对应模糊概念,后者引出模糊概念关系,由两者构成的模糊本体就是符合人的认知规律的客观世界在人脑中的必然反映。作为科学术语的"模糊",是指有效解决语词有限性与客观事物无限性矛盾的认知方式。模糊本体是本体的一般形式,更接近客观世界之真实,其模糊识别与模糊推理的功能更有利于支持人的认知活动。模糊本体内置于机器是信息处理智能化之必然,模糊本体表示的机器形式目前为OWL文档。举例示意了模糊本体的构建过程。
Ontology is the result of human cognizing objective things and their relations between each other, expressed in the form of concepts and concept relations each of which is denoted by a vocabulary. A person can just master limited vocabularies, so human cognition has inevitably two characteristics:a vocabulary refers to several concepts, namely reducing the amount of concept in the form of a concept with a varying extension replacing several ones with a fixed extension;a vocabulary refers to several concept relations, namely merging the types of concept relations in the form of a concept relation thought as a member of other concept relation in some degree of membership. The former derives the fuzzy concept, and the latter introduces the fuzzy concept relation, the two fuzzy elements can compose a fuzzy ontology which is the world in human brain obtained from cognizing the objective world according to the rule of human cognition. The word fuzzy as a scientific terminology means a cognitive style that is able to resolve the contradiction between the finite vocabularies and the infinite objective things. Fuzzy ontology is the general representation of ontology, and approaches to the essence of the objective world. Fuzzy ontology with functions of fuzzy diagnosis and fuzzy inference can effectively support human cognitive practices. It is necessary for intellectualization of information processing to put the fuzzy ontology into computers. The machine expression form of a fuzzy ontology is an OWL document at present. An example is given to illustrate the process of constructing a fuzzy ontology.