Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682212Special Issue20211201Some frank aggregation operators based on the interval-valued intuitionistic fuzzy numbers325342518010.22075/ijnaa.2021.23143.2482ENMaryam OrakiDepartment of Mathematics, Payame Noor University, Tehran, IranMadjid Eshaghi GordjiDepartment of Mathematics, Semnan University, Semnan, Iran0000-0002-0077-1142Halimeh ArdakaniDepartment of Mathematics, Payame Noor University, Tehran, IranJournal Article20210214In this article, we introduce the interval-valued intuitionistic fuzzy set (\textbf{IVIFS}), which are generalized forms of intuitionistic fuzzy set (\textbf{IFS}) and fuzzy set, this is because in intuitionistic fuzzy sets the non-membership function also applies to evaluations, and these sets are useful for modelling ambiguous concepts that abound in real problems. Here we try to look for new methods for more practical solutions in optimization problems for various sciences such as computer science, mathematics, engineering, medicine, psychology, climate and etc. First, with the introduction of t-norm Frank, an action we construct some Frank aggregation operators on interval-valued intuitionistic fuzzy numbers (\textbf{IVIFN}s), including the Frank weighted averaging operator, Frank-ordered weighted averaging operator, Frank hybrid weighted averaging operator, Frank geometric weighted averaging operator, Frank geometric-ordered weighted averaging operator, and Frank geometric hybrid weighted averaging operator. Also, examine some of the characteristics of these operators. In the following, we introduce two multiple attribute group decision-making methods (\textbf{MAGDM}) based on such operators. Finally, we provide illustrative examples of these methods.https://ijnaa.semnan.ac.ir/article_5180_9c48d5cbbdf22823420a6f4abf11fafd.pdf