Research Information System
Information Sciences, vol.729, 2026 (SCI-Expanded, Scopus)
The primary aim of this paper is to employ the concepts of circular q-rung orthopair fuzzy set (C-qROFS) and circular q-rung orthopair fuzzy value (C-qROFV) in multi-criteria group decision making (MCGDM). In a C-qROFS, membership degree and non-membership degree are represented by a circle, with its center defined by non-negative real numbers τ and υ, subject to the condition τq+υq≤1. Compared to existing fuzzy sets, the structure of C-qROFSs provides a more accurate representation of fuzzy information, due to its capability to model this information using the points on a circle with a specific center and radius. This gives decision makers the ability to assess objects within a broader and more adaptable context in a decision making process. In this study, after proposing some methods to convert collections of q-ROFVs into a C-qROFV, we establish an entropy measure for C-qROFSs, accompanied by the requisite axioms that this measure must fulfill. Additionally, a cross-entropy is introduced to calculate the divergence between two C-qROFSs. We also introduce Fisher information for C-qROFSs to measure the amount of information that a C-qROFS provides about an unknown parameter q. Lastly, we present an extended VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) approach rooted in both entropy and cross-entropy measures, designed to address MCGDM problems within the framework of q-ROFSs. The effectiveness of the proposed VIKOR methodology is demonstrated through a case study and compared to the performance of several existing methodologies. Additionally, sensitivity analysis is conducted to analyse the impact of parameters on the stated VIKOR index.