Circular Pythagorean Fuzzy Choquet Integral Operators and Applications to Multi-criteria Decision Making

Circular Pythagorean fuzzy sets or values (C-PFSs or C-PFVs) emerge as an innovative extension encompassing both circular intuitionistic fuzzy sets and Pythagorean fuzzy sets. The circular structure enhances the modeling of uncertain information by utilizing points within a circle characterized by a specific center and radius. In real-life problems, most criteria have interactive properties, so the concepts of fuzzy measure (FM) and fuzzy integral, which are successful in modelling the relationship between criteria, can be used. In this study, we present some Circular Pythagorean Fuzzy Choquet Integral Operators (C-PFCIOs) by employing the Choquet integral, a form of fuzzy integration, to model the interaction among criteria. These C-PFCIOs also generalize some weighted arithmetic aggregation operators for C-PFSs from the literature. Furthermore, a score function is proposed to rank C-PFVs. Finally, a novel algorithm based on these C-PFCIOs and this score function is introduced to be applied to a multi-criteria decision making problem on solar panel selection.