Quadratic entropy of uncertain variables

Uncertain variables, applied to modelling imprecise quantities, are fundamental concepts in uncertainty theory. In order to characterize the information deficiency of an uncertain variable, this paper proposes a definition of quadratic entropy. Compared with the traditional entropy, it is much easier to compute and has a wider range. Furthermore, the principle of maximum entropy is applied to quadratic entropy, and two theorems of maximum quadratic entropy with moment constraint are proved.