1 In this paper I will introduce the trapezoidal intuitionistic fuzzy numbers (IF numbers) and will prove some operations for them. Also I am going to propose a new ordering method for IF numbers in which I will consider two characteristic values of membership and non-membership functions for an IF number. These values are defined by the integral of the… (More)
The quadratic assignment problem (QAP) belongs to the class of NP-Hard problems and also is one of the hardest problems in this class. Today, regarding current hardware, solving the large size instances of this problem, using exact methods, is not possible in reasonable amount of time. In this way many heuristic (Meta-heuristic) and approximation methods… (More)
Bilevel linear programming is a decision making problem with a two-level decentralized organization. The " leader " is in the upper level and the " follower " , in the lower. Making a decision at one level affects that at the other one. In this paper, bilevel linear programming with inexact parameters has been studied and a method is proposed to solve a… (More)
In this paper we focus on a kind of linear programming with fuzzy numbers and multiple objectives. First by using α-cuts and fuzzy ranking ,we transform these problems to multi objective problem with fuzzy coefficients and crisp constraint then define necessarily efficiency points for new problem and for solving the problem try to find all of these… (More)
In this paper first we review two ranking methods for intuitionistic fuzzy numbers (IF numbers), then we proposed a new ordering method for IF numbers in which we consider two characteristic values of membership and non-membership for an IF number.
In this paper first, we find a canonical symmetrical trape-zoidal(triangular) for the solution of the fuzzy linear system A˜x = ˜ b, where the elements in A and˜b are crisp and arbitrary fuzzy numbers, respectively. Then, a model for fuzzy linear programming problem with fuzzy variables (FLPFV), in which, the right hand side of constraints are arbitrary… (More)
In this paper, we review previous methods for solving interval linear programming (ILP) problems. In most of these methods such as BWC, ILP, TSM, and SOM-2 methods, part of solution space is absolutely infeasible and non-optimal. To eliminate infeasible part of solution space, several methods such as MILP, and ITSM are proposed. The solution space of these… (More)
TOPSIS method is a most useful tool for solving MADM problems, also, Choquet integral method is another powerful method which, is able to manage interaction criteria. In this paper, we combine both methods to use from their benefits. First, we will introduce a new method for computing the distance between IT2FSs. Then, we proposed a hybrid method based on… (More)