Intuitionistic fuzzy originated interval type-2 fuzzy AHP: An application to damless hydroelectric power plants

Intuitionistic fuzzy sets (IFS) proposed by Atanassov (1983, 1986) are a generalization of ordinary fuzzy sets. They incorporate the degree of hesitation which is defined as 1 minus the sum of membership and non-membership degrees. Type-2 fuzzy sets were first introduced by Zadeh (1975) as an extension of the concept of an ordinary fuzzy set. Type-2 fuzzy sets have grades of membership that are themselves fuzzy. The membership function of a type-2 fuzzy set is three-dimensional, and it is the new third dimension that provides additional degrees of freedom for handling uncertainties. An intuitionistic fuzzy set can be converted to a Type-2 fuzzy set by subtracting its non-membership function from 1. Thus, an intuitionistic fuzzy multi-criteria decision making problem can be solved by using type-2 fuzzy multi-criteria decision making techniques. In this paper, an intuitionistic fuzzy originated interval type-2 fuzzy AHP method is developed and applied to the technology selection problem of a damless hydroelectric power plant. Damless hydroelectric power plants are environmentally friendly and sustainable energy production systems. Several criteria and damless technology alternatives along theSakarya River in Turkey are considered. Linguistic evaluations are considered in this multi-criteria damless technology selection problem.