Intro
Preface
Contents
About the Editor
Pythagorean Fuzzy Information Measures
A Survey on Recent Applications of Pythagorean Fuzzy Sets: A State-of-the-Art Between 2013 and 2020
1 Introduction
2 Basic Concepts and Operators of Pythagorean Fuzzy Sets
2.1 Basic Concept of the Pythagorean Fuzzy Sets
2.2 Principal Operations
2.3 Score and Accuracy Functions
2.4 Distance Measures
2.5 Pythagorean Fuzzy Aggregation Operators
3 Literature Review
3.1 Survey Methodology
3.2 Survey Results
4 Conclusion and Future Outlook
References

Some New Weighted Correlation Coefficients Between Pythagorean Fuzzy Sets and Their Applications
1 Introduction
2 Basic Notions of Pythagorean Fuzzy Sets
3 Correlation Coefficients Between PFSs
3.1 Some Existing/New CCPFSs Methods
3.2 Numerical Illustrations for Computing CCPFSs
4 Some Existing/New WCCPFSs Methods
4.1 Some Existing WCCPFSs Methods
4.2 New Methods of Computing WCCPFSs
4.3 Numerical Verifications of the WCCPFSs Methods
5 Determination of Pattern Recognition and Medical Diagnostic Problem via WCCPFSs
5.1 Applicative Example in Pattern Recognition

5.2 Applicative Example in Medical Diagnosis
6 Conclusion
References
Parametric Directed Divergence Measure for Pythagorean Fuzzy Set and Their Applications to Multi-criteria Decision-Making
1 Introduction
2 Basic Concepts
2.1 Intuitionistic Fuzzy Set [1]
2.2 Hesitant Fuzzy Set [32, 33]
2.3 Pythagorean Fuzzy Set [11, 16]
3 Proposed Parametric Directed Divergence Measure for Pythagorean Fuzzy Set (PFS)
3.1 Parametric Divergence Measure for PFSs
3.2 Parametric Symmetric Divergence Measure for PFSs

3.3 Some Properties of Parametric Symmetric Divergence Measure for PFSs
4 Decision-Making Method Based on Proposed Parametric Directed Divergence Measure for Pythagorean Fuzzy Set (PFS)
5 Illustrative Example
6 Conclusions
References
Some Trigonometric Similarity Measures Based on the Choquet Integral for Pythagorean Fuzzy Sets and Applications to Pattern Recognition
1 Introduction
2 Preliminaries
3 Trigonometric Similarity Measures Defined with the Choquet Integral For PFSs
4 Applications
4.1 Pattern Recognition Problem
4.2 Medical Diagnosis Problem

5 Conclusion
References
Isomorphic Operators and Ranking Methods for Pythagorean and Intuitionistic Fuzzy Sets
1 Introduction
2 Preliminaries
2.1 Related Definitions of Intuitionistic Fuzzy Sets and Pythagorean Fuzzy Sets
2.2 T-Norm and Its Dual T-Conorm
2.3 Four Types of Dual Archimedean T-Norm and S-Norm
3 Operations Isomorphism
3.1 Operations Isomorphism Between IFSs and PFSs
3.2 Operations Isomorphism Between IVIFSs and IVPFSs
3.3 Operations Isomorphism Between DHFSs and DHPFSs
4 Aggregation Operators Isomorphism