revision of sign distance method for ranking of fuzzy numbers

recently, abbasbandy and asady have been proposed a modificationof the distance based approach, namely ``sign distance method''.however, in this paper, it is shown that this method has some drawbacks, i.e.,the result is not consistent with human intuition for specialcases and this method cannot always logically infer rankingorder of the images of the fuzzy numbers. in this paper, wepresent a revised method which can avoid these problems forranking fuzzy numbers. also, we present several propertiesfor revised sign distance method while the original method does not have some ofthem.