The issue of normalization in the fuzzy Dempster-Shafer theory of evidence is investigated. We suggest a normalization procedure called<br />smooth normalization. It is shown that this procedure is a generalization of the usual Dempster normalization<br />procedure. We also show that the usual process of normalizing an individual subnormal fuzzy subset by proportionally<br />increasing the membership grades until the maximum membership grade is one is a special case of this smooth<br />normalization process and in turn closely related to the Dempster normalization process. We look an alternative<br />normalization process in the fuzzy Dempster-Shafer environment based on adding to the membership grade of subnormal<br />focal elements the amount by which the fuzzy subset is subnormal.
Yager, R. R. (1996). On the normalization of fuzzy belief structures. International Journal of Approximate Reasoning, 14(2–3), 127–153. https://doi.org/10.1016/0888-613x(96)00092-8