A note on defuzzification of type-2 fuzzy intervals

In this paper, we introduce a new form of defuzzification for a type-2 fuzzy interval over a referential interval [a,b]. This new procedure is performed in two steps: First, calculating the (crisp set) α-level average of the type-2 fuzzy interval via Aumann integration, with respect to α∈[0,1], over the class of all α-level sets of the corresponding type-1 fuzzy membership grades with x∈[a,b], and then taking the mid-point of the resultant interval for obtaining the defuzzification value. Furthermore, we prove the continuity of this defuzzification method with respect to a suitable metrics over the class of type-2 fuzzy intervals.