Quadratic entropy of uncertain sets

Uncertain set is a set-valued function on an uncertainty space, and attempts to model unsharp concepts. Firstly, a definition of quadratic entropy to characterize the uncertainty of uncertain sets resulting from information deficiency is proposed. Secondly, some properties of quadratic entropy for uncertain sets are given, and the relation between quadratic entropy and Liu's entropy of uncertain sets is discussed. Finally, a quadratic cross entropy for uncertain sets is investigated.