Soft set theory, fuzzy set theory and rough set theory are all mathematical tools for dealing with uncertainties and are closely related. Feng et al. introduced the notions of rough soft set, soft rough set and soft rough fuzzy set by combining fuzzy set, rough set and soft set all together. This paper is devoted to the discussions of the combinations of intervalvalued intuitionistic fuzzy set,...

The extension of rough set model is an important research direction in rough set theory. The aim of this paper is to present a new extension. At the first, we introduce a pair of dual intuitionistic fuzzy operators (Θ,Φ). And some important properties are examined about these these operators. Moreover, θ-lower and φ-upper approximation operators are defined, by using the operators, and a novel ...

The notion of intuitionistic fuzzy ideals with thresholds of an ordered semigroup is considered and some of its properties are given. An embedding theorem of the set of all intuitionistic fuzzy ideals with thresholds is presented and the homomorphic images and inverse images of intuitionistic fuzzy ideals with thresholds are studied too. 2010 Mathematics Subject Classification: 06F05

The Atanassov’s intuitionistic fuzzy (IF) set theory has become a popular topic of investigation in the fuzzy set community. However, there is less investigation on the representation of level sets and extension principles for interval-valued intuitionistic fuzzy (IVIF) sets as well as algebraic operations. In this paper, firstly the representation theorem of IVIF sets is proposed by using the ...

Intuitionistic logic is an important subsystem of the classical one. In intuitionistic logic the effective interpretation and mechanical extraction of programs from proofs are allowed. The programming interpretation of intuitionistic propositional logic by simply typed lambda-calculus is a significant part of interest of computer scientists. The intuitionistic natural deductions are actually th...

The concept of an intuitionistic fuzzy set can be reconsidered as an approach for defining a fuzzy set In cases where the available information is not enough to define an inaccurate concept of an ordinary fuzzy set. In sum, the theory of fuzzy sets is generalized intuitionistic fuzzy sets. It seems that quantitative research on multiattribute or multi-criteria decision making problems have been...

Select an appropriate project is a main key for contractors to increase their profits. In practice, in this area the uncertainty and imprecise of the involved parameters is so high. Therefore, considering fuzzy sets theory to deal with uncertainly is more appreciate. The aim of this paper is present a multi-criteria group decision-making model under an intuitionistic fuzzy set environment. Henc...

By extending the Bonferroni mean operator to the intuitionistic fuzzy situation, we introduce a new kind of aggregating operator: the induced generalized weighted Bonferroni mean(I-GWBM) operator. The I-GWBM operator includes many famous aggregation operators for intuitionistic fuzzy sets(IFSs) as special cases. Then, we generalize the I-GWBM operator by using quasi-arithmetic means and propose...