Abstract
In this paper, we extend the Bonferroni mean (BM) operator, generalized Bonferroni mean (GBM), and dual generalized Bonferroni mean (DGBM) operator with interval-valued 2-tuple linguistic Pythagorean fuzzy numbers (IV2TLPFNs) to propose interval-valued 2-tuple linguistic Pythagorean fuzzy weighted Bonferroni mean (IV2TLPFWBM) operator, interval-valued 2-tuple linguistic Pythagorean fuzzy weighted geometric Bonferroni mean (IV2TLPFWGBM) operator, generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted Bonferroni mean (GIV2TLPFWBM) operator, generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted geometric Bonferroni mean (GIV2TLPFWGBM) operator, dual generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted Bonferroni mean (DGIV2TLPFWBM) operator, dual generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted geometric Bonferroni mean (DGIV2TLPFWGBM) operator. Then the MADM methods are proposed with these operators. In the end, we utilize an applicable example for green supplier selection in green supply chain management to prove the proposed methods.
Keywords
Introduction
Pythagorean fuzzy set (PFS) [1, 2] is the generalization of the intuitionistic fuzzy set (IFS) which the square sum of the membership degree (MD) and the non-membership degree (NMD) is equal or less than 1. The PFS is proved to be more flexible than IFS since it has greater space than that of IFS. Hence, PFS can deal with the situations that can’t be dealt with by the IFS. The PFS has received more and more attention, which has been investigated and applied broadly [3, 4, 5, 6, 7, 8, 9, 10, 11, 12]. Some MADM methods in PFS have been developed. TOPSIS method was extended to solve MADM problems in PFS [13, 14, 15, 16, 17, 18]. Ren et al. [19] developed the Pythagorean fuzzy TODIM approach which consider the DMs’ psychological behaviors. Zhang [20] proposed the hierarchical QUALIFLEX approach in PFS. Chen [21] developed the Pythagorean fuzzy VIKOR models. Peng and Dai [22] studied the Pythagorean fuzzy stochastic MADM with prospect theory. Xue et al. [23] studied the Pythagorean Fuzzy LINMAP model with entropy theory. Wan et al. [24] studied Pythagorean fuzzy mathematical programming mean for MAGDM with Pythagorean fuzzy truth degrees. Garg [25] proposed linear programming for MADM with interval-valued PFS. Liang et al. [26] gave the projection method for MAGDM with PFNs based on GBM. Peng and Yang [27] proposed the MABAC Method for MAGDM with PFNs. Some information measures were investigated by many scholars [28, 29, 30, 31, 32, 33, 34]. Information aggregation operators are of great importance to the application of MADM and decision support [35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51]. The PFS had been generalized to accommodate interval values [52], linguistic arguments [53, 54, 55, 56, 57], hesitant fuzzy value [58, 59], etc.
Deng et al. [60] defined the concept of 2-tuple linguistic Pythagorean fuzzy sets (2TLPFSs) and developed some 2-tuple linguistic Pythagorean Hamy Mean operators in MADM. Deng et al. [61] proposed some 2-tuple linguistic Pythagorean Heronian mean operators in MADM. Deng and Gao [62] defined the TODIM method for MADM with 2-tuple linguistic Pythagorean fuzzy information. Furthermore, Wang et al. [63] defined the concept of interval-valued 2-tuple linguistic Pythagorean fuzzy sets (IV2TLPFSs) and developed some interval-valued 2-tuple linguistic Pythagorean Maclaurin symmetric mean (MSM) operators in MADM.
Bonferroni mean (BM) [64, 65, 66, 67, 68] is a famous aggregation operator which can depict interrelationships between any two arguments. Thus, the BM can supply a flexible mode to deal with the information fusion problem to solve MADM problems. Because IV2TLPFSs can easily describe the fuzzy information, and the BM can capture interrelationships between any two arguments, it is necessary to extend the BM operator to deal with the interval-valued 2-tuple linguistic Pythagorean fuzzy numbers (IV2TLPFNs). The paper’s goal is to expend some BM operators with 2TLPFNs, then to study some properties of these operators, and applied them to cope with the MADM with 2TLPFNs.
The structure of our article is organized as follows. Section 2 introduces the IV2TLPFSs. Section 3 combines IV2TLPFNs with WBM operator to develop IV2TLPFWBM and IV2TLPFWGBM operators. Section 4 combines IV2TLPFNs with GWBM operator to develop GIV2TLPFWBM and GIV2TLPFWGBM operators. Section 5 combines IV2TLPFNs with DGWBM operator to develop DGIV2TLPFWBM and DGIV2TLPFWGBM operators. Section 6 briefly introduces an application for safety assessment of construction project. Conclusions are given in Section 7.
Preliminaries
In this section, we introduce the concept of interval-valued 2-tuple linguistic Pythagorean fuzzy sets (IV2TLPFSs) based on the IVPFSs [34] and 2TLSs [38, 39].
2-tuple linguistic sets
Herrera and Martinez [38, 39] developed the 2-tuple fuzzy linguistic representation model based on the concept of symbolic translation. It is used for representing the linguistic assessment information by means of a 2-tuple
Pythagorean fuzzy sets
In this section, some basic concepts of the PFSs and IVPFSs have been reviewed over a fix set
where the functions
If If
If If
Zhang [10] extended the PFSs to the IVPFSs which is defined as followed over the fix set
where
Then, Wang et al. [63] proposed the concept of interval-valued 2-tuple linguistic Pythagorean fuzzy sets (IV2TLPFSs) based on the IVPFSs [34] and 2TLSs [38, 39].
where
If If If If If
(1)
(2)
(3)
(4)
Then
IV2TLPFWBM operator
To consider the attribute weights, the weighted Bonferroni mean (WBM) is defined as follows:
Then we extend WBM to fuse the IV2TLPFNs and propose the interval-valued 2-tuple linguistic Pythagorean fuzzy weighted Bonferroni mean (IV2TLPFWBM) aggregation operator.
Proof According to Definition 8, we can obtain
Thus,
Thereafter,
Thus,
Furthermore,
Therefore, Hence, Eq. (8) is kept. Then we need to prove that Eq. (8) is an IV2TLPFN. We need to prove two conditions as follows:
Let
Proof (1) Since
Then,
That means
(1) is maintained.
(2) Since
That means
The IV2TLPFWBM operator has the following properties.
Similarly to WBM, to consider the attribute weights, the weighted geometric Bonferroni mean (WGBM) is defined as follows:
Then we extend WGBM to fuse the IV2TLPFNs and propose the interval-valued 2-tuple linguistic Pythagorean fuzzy weighted geometric Bonferroni mean (IV2TLPFWGBM) operator.
Then we called
Proof From Definition 8, we can obtain,
Thus,
Therefore,
Then,
Thereafter,
Furthermore, Hence, Eq. (24) is kept. Then we need to prove that Eq. (24) is an IV2TLPFN. We need to prove two conditions as follows:
For the proof is similar to the IV2TLPFWBM operator, so it’s omitted here to save space. The IV2TLPFWGBM has the properties as follows.
GIV2TLPFWBM operator
The primary advantage of BM is that it can determine the interrelationship between arguments. However, the traditional BM can only consider the correlations of any two aggregated arguments. Thereafter, Beliakov et al. [65] extended the BM and introduced generalized BM (GBM) operator. Zhu et al. [67] introduced generalized weighted BM (GWBM) operator as follows.
Then we extend GWBM to fuse the IV2TLPFNs and propose the generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted Bonferroni mean (GIV2TLPFWBM) aggregation operator.
Proof According to Definition 8, we can obtain
Thus,
Thereafter, Furthermore,
Then,
Therefore, Hence, Eq. (37) is kept. Then we need to prove that Eq. (37) is an IV2TLPFN. We need to prove two conditions as follows:
For the proof is similar to the IV2TLPFWBM operator, so it’s omitted here to save space.
Then we will discuss some properties of GIV2TLPFWBM operator.
Similarly to GWBM, to consider the attribute weights, the generalized weighted geometric Bonferroni mean (GWGBM) is defined as follows:
Then we extend GWGBM to fuse the IV2TLPFNs and propose the generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted geometric Bonferroni mean (GIV2TLPFWGBM) aggregation operator.
Then we called
Proof From Definition 8, we can obtain,
Thus
Therefore, Thereafter, Then, Furthermore, Hence, Eq. (51) is kept. Then we need to prove that Eq. (51) is an IV2TLPFN. We need to prove two conditions as follows:
For the proof is similar to the IV2TLPFWBM operator, so it’s omitted here to save space. Then we will discuss some properties of GIV2TLPFWGBM operator.
DGIV2TLPFWBM operator
However, the GBM still has some drawbacks, GBWM and GWGBM can only consider the interrelationship between any three aggregated arguments. So Zhang et al. [68] introduced a new generalization of the traditional BM because the correlations are ubiquitous among all arguments. The new generalization of the traditional BM is called the dual GWBM (DGBM). The DGWBM is defined as follows:
where
Then we extend DGWBM to fuse the IV2TLPFNs and propose the dual generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted Bonferroni mean (DGIV2TLPFWBM) operator.
Proof According to Definition 8, we can obtain
Thus,
Thereafter,
Furthermore,
Then,
Therefore,
Hence, Eq. (65) is kept. Then we need to prove that Eq. (65) is an IV2TLPFN. We need to prove two conditions as follows:
For the proof is similar to the IV2TLPFWBM operator, so it’s omitted here to save space. Then we will discuss some properties of DGIV2TLPFWBM operator.
Similarly to DGWBM, to consider the attribute weights, the dual generalized weighted geometric Bonferroni mean (DGWGBM) is introduced as follows:
where
Then we extend DGWGBM to fuse the IV2TLPFNs and propose dual generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted geometric Bonferroni mean (DGIV2TLPFWGBM) aggregation operator.
Then we called
Proof From Definition 8, we can obtain,
Thus,
Therefore,
Thereafter,
Then,
Furthermore,
Hence, Eq. (76) is kept. Then we need to prove that Eq. (76) is an IV2TLPFN. We need to prove two conditions as follows:
For the proof is similar to the IV2TLPFWBM operator, so it’s omitted here to save space. Then we will discuss some properties of DGIV2TLPFWBM operator.
Numerical example
In this section we shall present a numerical example to select green suppliers in green supply chain management with IV2TLPFNs in order to illustrate the method proposed in this paper. There is a panel with five possible green suppliers in green supply chain management
In the following, we utilize the approach developed to select green suppliers in green supply chain management.
IV2TLPFN decision matrix
IV2TLPFN decision matrix
The aggregating results by the DGIV2TLPFWBM (DGIV2TLPFWGBM) operator
The score functions of the green suppliers
Ordering of the green suppliers
In order to show the effects on the ranking results by changing parameters of
Ranking results for different operational parameters of the DGIV2TLPFWBM operator
Ranking results for different operational parameters of the DGIV2TLPFWBM operator
Ranking results for different operational parameters of the DGIV2TLPFWGBM operator
Then, we compare our proposed method with other methods including IV2TLPFWA operator and IV2TLPFWG operator.
Compare with the computing results of Table 4, the results are slightly different to show the practicality and effectiveness of the proposed approaches. However, such as IV2TLPFWA operator and IV2TLPFWG operator, do not consider the information about the relationship between arguments being aggregated, and thus cannot eliminate the influence of unfair arguments on decision result. Our proposed DGIV2TLPFWBM and DGIV2TLPFWGBM operators consider the information about the relationship between arguments being aggregated.
Ordering of the green suppliers
In this paper, we investigate the MADM problems with IV2TLPFNs. Then, we utilize the Bonferroni mean (BM) operator, generalized Bonferroni mean (GBM) operator and dual generalized Bonferroni mean (DGBM) operator to develop some Bonferroni mean aggregation operators with IV2TLPFNs: interval-valued 2-tuple linguistic Pythagorean fuzzy weighted Bonferroni mean (IV2TLPFWBM) operator, interval-valued 2-tuple linguistic Pythagorean fuzzy weighted geometric Bonferroni mean (IV2TLPFWGBM) operator, generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted Bonferroni mean (GIV2TLPFWBM) operator, generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted geometric Bonferroni mean (GIV2TLPFWGBM) operator, dual generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted Bonferroni mean (DGIV2TLPFW BM) operator, dual generalized interval-valued 2-tuple linguistic Pythagorean fuzzy weighted geometric Bonferroni mean (DGIV2TLPFWGBM) operator. The prominent characteristic of these proposed operators are studied. Then, we have utilized these operators to develop some approaches to solve the MADM problems with IV2TLPFNs. Finally, a practical example for green suppliers selection in green supply chain management is given to verify the developed approach and to demonstrate its practicality and effectiveness. In the future, the application of the proposed aggregating operators of IV2TLPFNs needs to be explored in the decision making, risk analysis and many other fields under uncertain environments [69, 70, 71, 72, 73, 74, 75, 76].
Footnotes
Acknowledgments
The work was supported by the National Natural Science Foundation of China under Grant No. 71571128 and the Humanities and Social Sciences Foundation of Ministry of Education of the People’s Republic of China under Grant No. 16YJA630033.
