New Threshold Approximation Method Dealing with Complex Intuitionistic Fuzzy Information

Complex intuitionistic fuzzy sets (CIFSs) can represent problems in multicriteria decision-making that involve uncertainty and periodicity of semantics at the same time. CIFSs handle two-dimensional information that requires a long time and a huge number of calculations and processes. In this research, the complex intuitionistic shadowed set (CISHS) is defined as a novel threshold approximation method. CISHS is introduced to simplify processing and enhance the interpretation of outcomes obtained from CIFSs. The main idea of constructing CISHS is adding a complex non-membership function to the complex shadowed set (CSHS) range. Additionally, the basic operations, specifically complement, union, and intersection on CISHSs, are introduced. The properties of CISHSs are defined as null, absolute, and subset. Finally, an application to demonstrate the effectiveness of the proposed approach is employed by using an adaptive algorithm with CISHSs.