In this paper, we investigate the multiple attribute decision making with interval-valued intuitionistic fuzzy numbers. Motivated by the ideal of dependent aggregation, we develop the dependent interval-valued intuitionistic fuzzy Einstein ordered weighted average (DIVIFEOWA) operator, in which the associated weights only depend on the aggregated interval-valued intuitionistic fuzzy arguments and can relieve the influence of unfair hesitant fuzzy arguments on the aggregated results by assigning low weights to those “false” and “biased” ones and then apply them to develop some approaches for multiple attribute decision making with interval-valued intuitionistic fuzzy numbers. Finally, an illustrative example for evaluating the computer network security is given to verify the developed approach and to demonstrate its practicality and effectiveness.
Atanassov [1, 2] introduced the concept of intuitionistic fuzzy set (IFS) characterized by a membership function and a non-membership function, which is a generalization of the concept of fuzzy set [3] whose basic component is only a membership function. Later, Atanassov and Gargov [4, 5] further introduced the interval-valued intuitionistic fuzzy set (IVIFS). The fundamental characteristic of the IVIFS is that the values of its membership function and non-membership function are intervals. Xu [6] proposed some arithmetic averaging operators, such as, the interval-valued intuitionistic fuzzy weighted averaging (IVIFWA) operator, the interval-valued intuitionistic fuzzy ordered weighted averaging (IVIFOWA) operator and the interval-valued intuitionistic fuzzy hybrid aggregation (IVIFHA) operator. All the above operators are based on the algebraic operational laws of IVIFSs for carrying the combination process [7–14] and are not consistent with the limiting case of ordinary fuzzy sets [15]. Recently, Wang and Liu [16] treated the intuitionistic fuzzy aggregation operators with the help of Einstein operations. Therefore, how to extend the Einstein operations to aggregate the interval-valued intuitionistic fuzzy information is a meaningful work, which is also the focus of this paper.
In order to do so, the remainder of this paper is set out as follows. In the next section, we introduce some basic concepts related to interval-valued intuitionistic fuzzy sets and some existing interval-valued intuitionistic fuzzy Einstein aggregating operators. In Section 3, we develop the dependent interval-valued intuitionistic fuzzy Einstein ordered weighted average (DIVIFEOWA) operator. In Section 4, we apply the dependent interval-valued intuitionistic fuzzy Einstein ordered weighted average (DIVIFEOWA) operator to deal with multiple attribute decision making with interval-valued intuitionistic fuzzy information. In Section 5, an illustrative example for evaluating the computer network security is pointed out. In Section 6 we conclude the paper and give some remarks.
Preliminaries
Atanassov and Gargov [4, 5] further introduced the interval-valued intuitionistic fuzzy set (IVIFS), which is a generalization of the IFS.
Definition 1. [4, 5] Let X be an universe of discourse, An IVIFS over X is an object having the form:
where and are interval numbers, and , ∀ x ∈ X.
For convenience, let , , so .
Definition 2. Let be an interval-valued intuitionistic fuzzy number, the score function S of can be represented as follows:
Einstein operations of interval-valued intuitionistic fuzzy set
In this section, we shall introduce the Einstein operations on interval-valued intuitionistic fuzzy sets. the Einstein product (denoted by ) and Einstein sum (denoted by ) on two IVIFSs and , respectively, as follows [17].
Furthermore, Wang and Liu [17] proposed the interval-valued intuitionistic fuzzy Einstein ordered weighted average (IVIFEOWA) operator [18].
Definition 3. Let (j = 1, 2, ⋯ , n) be a collection of interval-valued intuitionistic fuzzy numbers. An interval-valued intuitionistic fuzzy Einstein ordered weighted average (IVIFEOWA) operator of dimension n is a mapping IVIFEOWA: Qn → Q, that has an associated vector w = (w1, w2,..., wn)T such that wj >0 and . Furthermore,
where (σ (1) , σ (2) , ⋯ , σ (n)) is a permutation of (1, 2, ⋯ , n), such that for all j = 2, ⋯ , n.
Some dependent aggregation operators with interval-valued intuitionistic fuzzy information
Definition 4. Let be a collection of interval-valued intuitionistic fuzzy numbers, the average value of the score function of is computed as
Definition 5. Let and be two interval-valued intuitionistic fuzzy numbers, then the Hamming distance between and is defined as follows [18]:
Definition 6. Let be be a collection of interval-valued intuitionistic fuzzy numbers, and the arithmetic mean scores of these interval-valued intuitionistic fuzzy numbers, then we define the standard deviation of these scores of these interval-valued intuitionistic fuzzy numbers as
Definition 7. Let be be a collection of interval-valued intuitionistic fuzzy numbers, then we call
the degree of similarity between the jth largest hesitant fuzzy values and the mean , where (σ (1) , σ (2) , ⋯ , σ (n)) is a permutation of (1, 2, ⋯ , n), such that for all j = 2, ⋯ , n.
In real-life situations, the interval-valued intuitionistic fuzzy numbers usually take the form of a collection of n preference values provided by n different individuals. Some individuals may assign unduly high or unduly low preference values to their preferred or repugnant objects. In such a case, we shall assign very low weights to these “false” or “biased” opinions, that is to say, the closer a preference value (argument) is to the mid one(s), the more the weight. As a result, based on (7), we define the IVIFEOWA operator weights as
Obviously, wj ≥ 0, j = 1, 2, ⋯ , n and .
Especially, if , for all i, j = 1, 2, ⋯ , n, then by (8), we have wj = 1/n, for all j = 1, 2, ⋯ , n.
By (3), we have
Since
and then we replace (9) by
We call (10) a dependent interval-valued intuitionistic fuzzy Einstein ordered weighted average (DIVIFEOWA) operator.
Theorem 1.Letbe be a collection of interval-valued intuitionistic fuzzy numbers, and letthe average value of the score function of , (σ (1) , σ (2) , ⋯ , σ (n)) is a permutation of (1, 2, ⋯ , n), such thatfor allj = 2, ⋯ , n. If , thenwi ≥ wj.
The normal distribution is one of the most commonly observed and is the starting point for modeling many natural process, it is usually found in events that are the aggregation of many smaller, but independent random events. Xu [19] introduced a normal distribution method to determine the weight of DOUWA operator. Motivated by the idea, we shall give another method for deriving the DIVIFEOWA weights:
where and σ are the arithmetic mean and the standard deviation of these hesitant fuzzy arguments variables , respectively, (σ (1) , σ (2) , ⋯ , σ (n)) is a permutation of (1, 2, ⋯ , n), such that for all j = 2, ⋯ , n.
Consider that wj ≥ 0, j = 1, 2, ⋯ , n and , then by (11), we have
then by (3), we have
Since
then, (13) can be rewritten as
Obviously, (14) is also a neat and dependent interval-valued intuitionistic fuzzy Einstein ordered weighted average (DIVIFEOWA) operator.
From (8) and (11), we know that all the associated weights of the DIVIFEOWA operator only depend on the aggregated interval-valued intuitionistic fuzzy numbers, and can relieve the influence of unfair arguments on the aggregated results by assigning low weights to those “false” and “biased” ones, and thus make the aggregated results more reasonable in the practical applications.
An approach to multiple attribute decision making with interval-valued intuitionistic fuzzy information
In this section, we shall apply DIVIFEOWA operator to the multiple attribute decision making problems
with interval-valued intuitionistic fuzzy numbers. Let A ={ A1, A2, ⋯ , Am } be a discrete set of alternatives, and G ={ G1, G2, ⋯ , Gn } be the set of attributes. The information about attribute weights is completely known. Suppose that is the interval-valued intuitionistic fuzzy decision matrix, [aij, bij] ⊂ [0, 1], [cij, dij] ⊂ [0, 1], bij + dij ≤ 1, i = 1, 2, ⋯ , m, j = 1, 2, ⋯ , n.
In the following, we apply the DIVIFEOWA operator to multiple attribute decision making with interval-valued intuitionistic fuzzy information. The method involves the following steps:
Step 1. Utilize the decision information given in matrix , and the DIVIFEOWA operator
Step 2. Calculate the scores of the collective overall values to rank all the alternatives Ai (i = 1, 2, ⋯ , m) and then to select the best one(s).
Step 3. Rank all the alternatives Ai (i = 1, 2, ⋯ , m) and select the best one(s) in accordance with and .
Step 4. End.
Numerical example
This section presents a numerical example to evaluate the computer network security with uncertain linguistic information to illustrate the method proposed in this paper. There are five possible computer network systems Ai (i = 1, 2, 3, 4, 5) for four attributes Gj (j = 1, 2, 3, 4). The four attributes include the tactics (G1), technology and economy (G2), logistics (G3) and strategy (G4), respectively. The five possible computer network systems Ai (i = 1, 2, 3, 4, 5) are to be evaluated using the interval-valued intuitionistic fuzzy information by the decision maker under the above four attributes, as listed in the following matrix.
In the following, we apply the DIVIFEOWA operator to multiple attribute decision making for evaluating the computer network security with interval-valued intuitionistic fuzzy information. The method involves the following steps:
Step 1. If we apply the DIVIFEOWA operator to decision making with interval-valued intuitionistic fuzzy information, we get the weight of DIVIFEOWA operator is:
Step 2. Utilize the decision information given in matrix , and the DIVIFEOWA operator, we obtain the overall preference values of the computer network systems Ai (i = 1, 2, ⋯ , 5).
Step 3. Calculate the scores of the overall interval-valued intuitionistic fuzzy preference values
Step 4. Rank all the computer network systems Ai (i = 1, 2, 3, 4, 5) in accordance with the scores of the overall preference values : A5 ≻ A2 ≻ A4 ≻ A1 ≻ A3, and thus the most desirable computer network systems is A5.
Conclusion
In this paper, we investigate the multiple attribute decision making with interval-valued intuitionistic fuzzy numbers. Motivated by the ideal of dependent aggregation, we develop the dependent interval-valued intuitionistic fuzzy Einstein ordered weighted average (DIVIFEOWA), in which the associated weights only depend on the aggregated interval-valued intuitionistic fuzzy arguments and can relieve the influence of unfair hesitant fuzzy arguments on the aggregated results by assigning low weights to those “false” and “biased” ones and then apply them to develop some approaches for multiple attribute decision making with interval-valued intuitionistic fuzzy numbers. Finally, an illustrative example for evaluating the computer network security is given to verify the developed approach and to demonstrate its practicality and effectiveness.
Footnotes
Acknowledgments
The work was supported by the Science Development Program of Shunde, Foshan, Guangdong in 2012 (20120202088) and the Research Project of Education Science in Guangdong province during the Twelfth Five-year Guideline in 2012 (2012JK303).