Fermatean fuzzy sets in multiset framework with application in diagnostic process based on composite relations
Doonen Zuakwagh, Paul Augustine Ejegwa, Abolape Deborah Akwu · 2024
The term Fermatean fuzzy sets (FFSs) offers a capable approach of managing hesitation and imprecision in decision-making (DM) by widening the space of membership degree (MD) and non-member degree (NMD) of intuitionistic fuzzy sets (IFSs) and Pythagorean fuzzy sets (PFSs). FFSs are essential tools in computational intelligence applicable in complex decision-making (CDM). Many authors have buttressed this fact in many researches. However, the structure of FFSs is incapable of handling CDM involving repeated criteria. Hence, by incorporating the idea of multiset into FFSs, CDM cases with repeated criteria can be effectively handled. In this chapter, a concept of FFS in multiset framework (FFSMF) is developed to take care of CDM involving repeated criteria. The fundamentals of the FFSMF are discussed illustratively. In addition, we discuss two composite relations on FFSMF for the purpose of application. Furthermore, the application of the composite relations on FFSMF is discussed in the diagnostic process of some selected diseases. Finally, we contrast the effectiveness of FFSMF in CDM with that of FFS to showcase the adequacy of FFSMF in managing CDM problems.