Abstract:

The negation in fuzzy knowledge can be divided into three distinct classes: contradictory negation, opposite negation and medium negation. FScom is a fuzzy set used to differentiate these three negations. On the basis of FScom,the set description of fuzzy knowledge and its different kinds of negations were further investigated, and one improved kind of fuzzy set IFScom is proposed. Also, its characteristic, operation and related properties are also investigated.

Key words: fuzzy knowledge; contradictory negation; opposite negation; medium negation; fuzzy set