1. Introduction
Multi-attribute group decision making in uncertain environments (MAGDM) is an important component of modern decision-making science, and its theory and methods have been widely applied in many fields [
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
11]. However, with the continuous expansion and application of decision theory, limited by individual cognitive level and thinking characteristics, people often make decisions in practical problems with a certain degree of ambiguity and uncertainty. In order to describe and deal with this fuzzy phenomenon, Zadeh [
12] proposed the fuzzy set (FS) theory in 1965 by introducing the concept of membership to express subjective opinions. Subsequently, some extended forms of FS have been proposed, such as interval valued fuzzy set (IVFS) [
13], intuitionistic fuzzy sets (IFS) [
14], Pythagorean fuzzy set (PFS) [
15] and the q-rung orthopair fuzzy set (q-ROFS) [
16]. Among these, the q-ROFS is an extension that generalizes the PFS and IFS, which satisfies that the sum of the q-power of membership degree and the q-power of non-membership degree is restricted to [0, 1]; this solved the phenomenon that IFS and PFS are limited in the scope of information expression. Both IFS and PFS are special cases of the q-ROFS when
q takes different values. We can contend that q-ROFS is more comprehensive. Consequently, q-ROFS offers decision makers a broader spectrum for articulating their uncertain information [
17,
18,
19,
20,
21,
22,
23,
24].
None of the existing models can effectively represent partial ignorance of the data or its fluctuations at specific phases of time. However, in complex data sets, uncertainty and vagueness in the data often coexist with variations in the data’s phases (periodicity). To address such problems, the concept of the complex fuzzy set (CFS) [
25] was first proposed by Ramot et al. Because the CFS cannot only expand the range of membership and non-membership values from the unit interval to the unit circle of the complex plane, but also the complex membership and complex non-membership values can be expressed in polar coordinates. Therefore, it has received widespread attention from scholars both domestically and internationally. Rahman et al. [
26] proposed an algorithm for a decision-making process using a complex Pythagorean fuzzy set and applied them to a hospital setting for COVID-19 patients. Mahmood et al. [
27] studied Heronian mean operators for managing complex picture fuzzy uncertain linguistic settings. Azam et al. [
28] developed a decision-making approach for the evaluation of information security management under a complex intuitionistic fuzzy set environment. Garg et al. [
29] proposed a decision-making approach based on generalized aggregation operators with complex single-valued neutrosophic hesitant fuzzy set information. Janani et al. [
30] defined complex probabilistic fuzzy set and proposed some aggregation operators in group decision making extended to TOPSIS. Mahmood et al. [
31] proposed some Bonferroni mean operators based on a bipolar complex fuzzy setting and applied them in multi-attribute decision making. Harish et al. [
32] developed some complex q-rung orthopair fuzzy Hamy mean operators. Also, Liu et al. [
33] proposed some complex q-rung orthopair fuzzy aggregation operators and used them in multi-attribute group decision making. However, it is difficult to accurately represent the membership function values for complex fuzzy sets, and there is a lack of expression of non-membership degrees; this leads to inaccurate understanding of the degree of ambiguity, which can easily affect decision results.
In reality, decision makers may need to express both interval values and corresponding fixed-value evaluation information. This mixed fuzzy information cannot be represented by the above single form of Fuzzy set and its extended set. For this reason, Jun et al. [
34] put forward the concept of the cubic set (CS), which is a new extension of FS, characterized by the mixed description of interval information and deterministic information, that is, a CS is composed of an IVFS and an FS. Compared with FS, cubic set has the advantage that a set contains different forms of fuzzy evaluation information at the same time, which can meet the requirements of decision makers to express different forms of evaluation information for an evaluation object in real situations. Shahzad et al. [
35] proposed some operations and properties of the cubic intuitionistic set with application in multi-criteria decision making. Muhammad et al. [
36] studied cubic bipolar fuzzy set with application to multi-criteria group decision making using geometric aggregation operators. Wang et al. [
37] discussed similarity and Pythagorean reliability measures of multivalued neutrosophic cubic set. Muhammad et al. [
38] defined cubic Pythagorean fuzzy soft set and applied them in multi-attribute decision making. Farhadinia [
39] defined cubic hesitant fuzzy set and presented a cubic hesitant fuzzy set characterized in the form of triangular, where is known as triangular cubic hesitant fuzzy set. Zhang et al. [
40] proposed some cubic q-rung orthopair fuzzy Heronian mean operators and discussed their applications in multi-attribute group decision making. However, cubic fuzzy information is unable to capture the partial uncertainty of data and its variations at specific time phases during execution. When handling substantial amounts of uncertain information with phase changes, such as in digital and image processing, cubic sets prove ineffective. At present, Ren et al. [
41] proposed a new hybrid model called complex cubic q-rung orthopair fuzzy set (CCuq-ROFS) by combining complex fuzzy set and Cq-ROFS. It contains more information than complex fuzzy sets and cubic sets, so it is more suitable to deal with complex MAGDM problems.
Meantime, the Maclaurin symmetric mean (MSM) operator was originally introduced by Maclaurin [
42] and then developed by Detemple and Robertson [
43]. The prominent characteristic of the MSM is that it can capture the interrelationship among the multi-input arguments. The MSM operator can provide more flexible and robust information fusion and make it more adequate to solve MADM in which the attributes are independent. Moreover, for a given collection of arguments, the MSM operator is monotonically decreasing with respect to the values of the parameter, which can reflect the risk preferences of the decision makers in practical situations. In the past few years, the MSM has received more and more attention, and many important results both in theory and application have been developed [
44,
45,
46,
47,
48,
49]. Ali et al. [
50] proposed complex intuitionistic fuzzy Maclaurin symmetric mean operators and their applications for emergency program selection. Song et al. [
51] proposed some single-valued neutrosophic uncertain linguistic Maclaurin symmetric mean operators and their application to multiple-attribute decision making. Aliya et al. [
52] proposed Maclaurin symmetric mean aggregation operators based on cubic Pythagorean linguistic fuzzy number. Mu et al. [
53] proposed a novel approach to multi-attribute group decision making based on interval-valued Pythagorean fuzzy power Maclaurin symmetric mean operator. Liu et al. [
54] propose multiple-attribute decision-making method based on power generalized Maclaurin symmetric mean operators under normal wiggly hesitant fuzzy environment. Yang et al. [
55] studied three-way decisions based on q-rung orthopair fuzzy 2-tuple linguistic sets with generalized Maclaurin symmetric mean operators.
The previous discussions have shown that many of the developed operators rely on algebraic products and algebraic sums. Nonetheless, it is essential to recognize that these operations are not the sole options available for FSs. Hamacher [
56] introduced the Hamacher operations, which encompass the Hamacher product and the Hamacher sum. Both the Hamacher product and Hamacher sum serve as effective alternatives to the conventional algebraic product and algebraic sum. Additionally, the Hamacher t-conorm and Hamacher t-norm are considered as more general and flexible generalizations of the algebraic and Einstein t-conorm and t-norm, respectively. Despite their potential advantages, a review of the existing literature on aggregation operators reveals a scarcity of research exploring the application of Hamacher operations in developing new operators. Therefore, it is imperative to undertake research on aggregation operators that leverage Hamacher operations in the context of CCuq-ROF information. The contributions of this paper are outlined below:
(1) We propose some new aggregation operators for CCuq-ROFS, such as the complex cubic q-rung orthopair fuzzy Hamacher average (CCuq-ROFHA) operator, the weighted complex cubic q-rung orthopair fuzzy Hamacher average (WCCuq-ROFHA) operator, the complex cubic q-rung orthopair fuzzy Hamacher Maclaurin symmetric mean (CCuq-ROFHMSM) operator and the weighted complex cubic q-rung orthopair fuzzy Hamacher Maclaurin symmetric mean (WCCuq-ROFHMSM) operator;
(2) The combination of Hamacher t-norm and t-conorm based operations with the MSM operator not only captures the interrelationships among multiple attributes but also enhances decision-making flexibility through the incorporation of additional parameters γ and k;
(3) The proposed operators are inherently more general, offering a variety of aggregation methods by substituting specific values for the parameters γ and k.
The structure of the remaining sections in this paper is as follows:
Section 2 introduces the fundamental concepts of CCuq-ROFS, Hamacher operations and MSM operators. In
Section 3, we focus on the development of Hamacher aggregation operators within the complex cubic q-rung orthopair fuzzy environment and discuss their properties.
Section 4 presents a brief study on the MAGDM approach, incorporating the proposed Hamacher aggregation operators. In
Section 5, we provide an example to demonstrate the application of the proposed method. Additionally, we conduct sensitivity analysis and comparison analysis. Finally,
Section 6 provides a brief conclusion.
4. A Method for MAGDM with CCuq-ROF Information
In this section, a MAGDM method for complex cubic q-rung orthopair fuzzy numbers are developed using the proposed WCCuq-ROFHMSM operator.
For a MAGDM problem, suppose is the set of alternatives, is the set of experts, is the set of attributes. Let and be the weight vectors of attributes and experts, respectively, where , , , . Suppose that for attribute of alternative , each expert expresses his /her assessment information by a complex cubic q-rung orthopair fuzzy decision matrix . In the following, the WCCuq-ROFHMSM operator is applied to the MAGDM with CCuq-ROF information.
Step 1. Normalize each decision matrix .
The attributes present in the decision matrix can be categorized into two types: cost type and benefit type. To simultaneously account for both types of attributes, we must normalize the decision matrix using the following formula:
However, if all the attributes are of the benefit type, there is no need to normalize the decision matrix.
Step 2. The comprehensive complex cubic q-rung orthopair fuzzy decision matrix is evaluated.
Using the proposed WCCuq-ROFHMSM operator to aggregate all the individual complex cubic q-rung orthopair fuzzy decision matrixes into the collective complex cubic q-rung orthopair fuzzy decision matrix .
The comprehensive evaluation value of each attribute by experts in each alternative is computed as follows:
Step 3. The comprehensive complex cubic q-rung orthopair fuzzy value is evaluated.
Using the proposed WCCuq-ROFHMSM operator to aggregate all the individual complex cubic q-rung orthopair fuzzy values
into the collective complex cubic q-rung orthopair fuzzy value
:
Step 4. Calculation of score function and accuracy function.
Calculate the score function and accuracy function for each comprehensive value .
Step 5. Ranking of alternatives.
The alternatives are ranked base on their score function and accuracy function , and the most suitable alternative is selected.
Step 6. End.
The flowchart of the proposed algorithm is given in
Figure 1.
5. Application of the Proposed Method
5.1. A Numerical Example
In this section, a numerical example is presented to show potential evaluation of quality of digital government services with complex cubic q-rung orthopair fuzzy information in order to illustrate the method proposed in this paper.
In recent years, with “Internet plus government service” as the starting point, the “run at most once” reform as the overall traction, and the integrated data platform as the key support, Chongqing has achieved remarkable results in government digital governance, which is very representative. In addition, Chongqing has achieved significant results in economic development and political reform due to its geographical advantage and has a certain exemplary role in the country. Therefore, this study takes Chongqing as an example to comprehensively evaluate the quality of its digital government services.
There are five Chongqing government affairs WeChat official accounts
(Chongqing Medical, Chongqing Transportation, Chongqing Weather, Chongqing Public Security Bureau, Chongqing Taxation) to evaluate. The three experts
select the best account from four attributes:
is platform design quality;
is the information and administrative services;
the information technology and
is the government WeChat information environment. The weighting vectors of attributes and experts are
and
, respectively. The five official accounts
are to be evaluated using the complex cubic q-rung orthopair fuzzy information using the decision maker under the above four attributes, and the CCuq-ROF decision matrix
is shown in
Table 1,
Table 2 and
Table 3.
Step 1. Normalize the individual decision matrix .
Since all attributes are of beneficial types, there is no requirement to normalize each decision matrix. Therefore, the decision matrix provided in
Table 1,
Table 2 and
Table 3 is utilized for subsequent analysis.
Step 2. Comprehensive decision matrix of experts is evaluated.
Based on the weight of experts and decision matrixes, comprehensive decision matrix
is obtained using the WCCuq-ROFHMSM operator (let
,
,
). Then the comprehensive decision matrix
is shown in
Table 4.
Step 3. Comprehensive value evaluation.
Similarly, there is no requirement to normalize decision matrix
. The WCCuq-ROCFHMSM operator is utilized to aggregate all the complex cubic q-rung orthopair cubic fuzzy information into the overall complex cubic q-rung orthopair cubic fuzzy values
. The aggregated results are provided in column 2 of
Table 5.
Step 4. Calculation of score and accuracy functions.
Now, calculate the score function
for each
. The calculated score functions are given in column 3 of
Table 5. Since each
is different, thus the
of any
is no need to calculate.
Step 5. Ranking of all accounts.
Finally, the ranking results all accounts
on the basis of
are provided in column 4 of
Table 5. It can be seen from
Table 5 that A
4 is the best choice among the five accounts.
The determination of the optimal alternative relies upon the values of parameters q, γ and k. Likewise, various aggregation operators might yield distinct ranking outcomes based on their aggregation characteristics. It is crucial to examine the method’s effectiveness by considering the sensitivity of parameter value selection and the applied aggregation operator. Therefore, in the subsequent sections, sensitivity and comparative analyses have been carried out.
5.2. Sensitivity Analysis
To illustrate the effectiveness of the developed MAGDM approach using the WCCuq-ROFHMSM operator, a sensitivity analysis was carried out in several stages by altering the values of parameters q and γ, and by considering various values for parameter k. The subsequent sections provide an analysis and discussion of the repercussions of these variations on the outcomes.
Firstly, by varying parameter
q across integer values within the range of 2 to 10, while simultaneously maintaining the other two parameters fixed at
k = 2 and
γ = 1, the obtained outcomes have been condensed and presented in
Table 6. The outcomes indicate that as parameter
q undergoes alteration, there is a corresponding shift in the scores and subsequent ranking order of all available alternatives. However, it consistently remains that the optimal choice is A
4, and the least favorable choice is A
2 in the most cases with the variations in parameter
q. This observation suggests that parameter
q not only extends the scope of potential decisions but also exerts influence over the final determination.
Secondly, parameter γ is varied using integer values within the interval [1, 10], while parameters
k = 2 and
q = 2 remain constant. The computed outcomes are presented in
Table 7. Examination of the results in
Table 7 reveals that as parameter γ undergoes variation, the scores and ranking order of distinct alternatives correspondingly shift. In this context, it is noteworthy that the optimal alternative consistently remains as A
4 for all considered variations in parameter γ, while the least favorable alternative changes. This observation implies that parameter γ introduces a degree of adaptability into the aggregation process and exerts an influence on the ultimate decision.
Thirdly, the impact of interrelationships among multiple attributes is assessed through the variation in parameter
k, while maintaining fixed values for parameters
q = 2 and γ = 1. The computed outcomes are presented in
Table 8, indicating that the interplay between multiple attributes does exert a certain influence on the ultimate decision. Notably, due to the incorporation of interrelationship considerations within the proposed aggregation operators, the resultant outcomes tend to exhibit a higher degree of realism. In this specific case, it is worth highlighting that the optimal alternative consistently remains A
4 across all examined variations in parameter
k.
5.3. Comparison Analysis
The theory of complex cubic q-rung orthopair fuzzy sets (CCuq-ROFSs) serves as an effective framework for describing intricate fuzzy information within the real-world context. Due to the inclusion of parameter q within Ccuq-ROFSs, which enables the adjustment of the range of complex fuzzy information expression, they exhibit superiority over both complex cubic intuitionistic and complex cubic Pythagorean fuzzy sets. Hamacher aggregation operators play a crucial role as a tool for generating operational rules based on complex cubic q-rung orthopair fuzzy numbers (Ccuq-ROFNs).
In order to provide further validation of the efficacy of the methodologies introduced in this paper, several existing approaches are employed to solve the same illustrative example, and the outcomes are juxtaposed for comparison. Within this subsection, an encompassing analysis is conducted to succinctly encapsulate the utility and preeminence of the innovative techniques. In this subsection, we compare our proposed approach with complex cubic Pythagorean fuzzy weighted average (CCPFWA) operator and complex cubic Pythagorean fuzzy weighted geometric (CCPFWG) operator proposed by Chinnadurai et al. [
59], complex cubic q-rung orthopair fuzzy weighted average (Ccuq-ROFWA) operator and complex cubic q-rung orthopair fuzzy weighted geometric (Ccuq-ROFWG) operator proposed by Ren et al. [
41], complex cubic intuitionistic fuzzy Bonferroni mean (CCIFBM) operator and complex cubic intuitionistic fuzzy weighted Bonferroni mean (CCIFWBM) operator and proposed by Mahmood et al. [
60].
Among the above-mentioned operators, the Ccuq-ROFWA operator, Ccuq-ROFWG operator, CCPFWA operator and CCPFWG operator do not consider any interrelationship between attributes. Also, neither of these operators have any additional parameters. However, the CCIFBM operator, CCIFWBM operator and the proposed operators have different types of interrelationships between input arguments, and there are some additional parameters involved in these operators as per their basic definitions. Furthermore, the CCIFWBM operator considers the interrelationship between any two attributes, while the proposed operators can take into account not only the interrelationship among multiple attributes but can also offer flexibility in the aggregation process, due to the involvement of additional parameters.
In this subsection, for using CCIFWBM operator, and the parameters are taken as
. And for applying WCCuq-ROFHMSM aggregation operators, the selected values of their additional parameters are
. The comparison results between the proposed method with existing methods are discussed in
Table 9. From
Table 9, although the ranking is slightly different, it can be noted that the best alternative obtained from all the operators under the same example is almost the same.
According to comparisons with the existing methods, and compared with the help of ranking, the proposed methods based on Ccuq-ROFSs in this paper are better than the existing methods for aggregating the complex cubic fuzzy information. Moreover, in comparison with the existing approaches, our methods incorporate supplementary parameters that serve to encapsulate decision makers’ preferences. This enables decision makers to select diverse values in accordance with their risk preferences. Drawing from the aforementioned comparisons and analyses, our method emerges as a more practical, potent and logically sound approach for resolving real-world issues compared to existing methods. Meanwhile, our proposed method is superior to these methods by not only effectively capturing the interrelations among multiple input arguments but also offering decision makers the flexibility to describe their fuzzy information across a broader range. Additionally, our method empowers decision makers to select their risk preferences based on the monotonically decreasing value of the parameter. In summary, our proposed approach is versatile and well suited for dealing with MAGDM problems under Ccuq-ROF environment.