General IF-sets with triangular norms and their applications to group decision making

A concept of general IF-sets, i.e. “intuitionistic” fuzzy sets according to Atanassov, with triangular norm-based hesitation degrees is introduced and developed. That concept is used to construct flexible algorithms of group decision making which involve relative scalar cardinalities defined by means of generalized sigma counts of fuzzy sets. Two cases of group decisions, based on individual or social fuzzy preference relations, are considered.