Abstract
This paper studied the two-sided matching problem based on interval-valued intuitionistic fuzzy sets and matching aspirations, the related concepts of which were described. In order to solve this problem, the interval-valued intuitionistic fuzzy matrices were transformed into interval score matrices and score matrices. Based on the score matrices, matching aspiration matrix, and matching matrix, a two-sided matching model under the conditions of one-to-one two-sided matching was developed. Therein, matching aspirations were calculated using the maximum reciprocal-deviation principle. Considering the statuses of all agents on both sides were the same in most situations, the two-sided matching model was converted into a single-objective optimization model using the linear weighted method. “Optimal” two-sided matching was obtained by solving the model. At the conclusion of the study, the feasibility and effectiveness of the proposed method was illustrated with an example of matching executives with positions.
Keywords
Introduction
Two-sided matching is a common problem that exists in real life. Examples include symmetric stable marriage, matching in advertising, college admissions, matching service providers and customers, assignments for trainees to software project requirements, etc. [7, 20]. Gale and Shapley initially studied the stable marriage and college admissions models, and proposed the well-known Gale-Shapley algorithm [1]. This was followed by the study of various two-sided matching problems by many other scholars [2, 18]. Because the “optimal” two-sided matching alternative can enhance the satisfaction degree of agents, studying the theories and methods for two-sided matching has important theoretical significance and practical application value.
At present, the theories and methods for two-sided matching with ordinal numbers, order relations, and linguistic terms have been useable. However, considering the complexity and fuzzy uncertainty of the two-sided matching problem, the cognitive limitation of agents, the preferences of two-sided agents are sometimes in the format of interval-valued intuitionistic fuzzy sets, which was an idea first introduced by Atanassov and Gargov and is an extension of the intuitionistic fuzzy sets [8, 9]. The difference is that the degrees of membership and non-membership are interval-valued numbers, not real numbers. Hence, it can depict the fuzzy nature of objective things more skillfully [9]. The theory of interval-valued intuitionistic fuzzy set, which is provided in Table 1, has been widely used in the field of decision making [5, 21]. However, the theory is seldom applied to the field of two-sided matching decisions. If the two-sided matching decision is investigated from the perspective of matching aspiration, then the success rate of two-sided matching is improved. Therefore, studying the two-sided matching problem with interval-valued intuitionistic fuzzy sets from the point of view of matching aspiration is significant.
In view of this, this paper applied the theory of interval-valued intuitionistic fuzzy set to the field of two-sided matching decisions, and studied the problem from the perspective of matching aspiration. The results of this paper determined that the main advantage of the proposed method is that it is able to solve two-sided matching problems with interval-valued intuitionistic fuzzy sets and can reflect the matching aspirations of agents.
Preliminary
Interval-valued intuitionistic fuzzy set
Here , and denote the proportion of support, opposition, and abstention, respectively, in , and satisfy
In the two-sided matching decision problem, let ∂ = {∂1, ∂2, …, ∂ p } and ℘ = {℘ 1, ℘ 2, …, ℘ q } be the set of two-sided agents, where ∂ i and ℘ j denote the ith agent of side ∂, and the jth agent of side ℘, and 2 ≤ p ≤ q. Let P = {1, 2, …, p} , Q = {1, 2, …, q}.
The problem of two-sided matching with interval-valued intuitionistic fuzzy sets considering matching aspirations
In the two-sided matching problem, let be the interval-valued intuitionistic fuzzy matrix from side ∂ to ℘, where . Here, denotes the degree of interval-valued satisfaction for agent ∂ i towards ℘ j , and denotes the degree of interval-valued dissatisfaction for agent ∂ i towards ℘ j . Let be the interval-valued intuitionistic fuzzy matrix from side ℘ to ∂, where . Here, denotes the degree of interval-valued satisfaction for agent ℘ j towards ∂ i , and denotes the degree of interval-valued dissatisfaction for agent ℘ j towards ∂ i . Let Δ = [δ ij ] p×q be the matching aspiration matrix, where δ ij denotes the matching aspiration between agents ∂ i and ℘ j . Let ϒ* be the “optimal” two-sided matching.
Based on the above analysis, the problem described in this paper is how to obtain “optimal” two-sided matching ϒ* based on interval-valued intuitionistic fuzzy matrices and , and the matching aspiration matrix Δ = [δ ij ] p×q. The research strategy for this study is provided in Fig. 1.
The decision of two-sided matching with interval-valued intuitionistic fuzzy sets considering matching aspirations
The model of two-sided matching considering scores and matching aspirations
Firstly, according to Equation (1), interval-valued intuitionistic fuzzy matrices and were transformed into interval score matrices and , where
If the interval scores and are considered to be uniformly distributed, then the interval score matrices and can be transformed into the score matrices and , where the following is true:
Then, the 0-1 variable y
ij
can be introduced, where . Hence, the matching matrix Y = [y
ij
] p×q can be built. Based on the score matrices and , matching aspiration matrix Δ = [δ
ij
] p×q and matching matrix Y = [y
ij
] p×q, the model of two-sided matching can be constructed. The greater the interval score, the higher the degree of satisfaction. Hence, the interval score is taken as the objective of maximization. Furthermore, Model (M-1) of two-sided matching under the condition of one-to-one two-sided matching constraint can be developed as follows:
In Model (M-1), the value of δ ij is unknown. In order to determine δ ij , the analysis combined with the value of absolute difference is given below.
If becomes increasingly greater, then the difference of the degree of satisfaction between ∂
i
and ℘
j
also becomes increasingly greater. In this case, the success rate of matching ∂
i
with ℘
j
will decrease. Namely, δ
ij
will become smaller, and vice versa. For convenience sake, let be the reciprocal difference of . In order to enhance the success rate of matching in reality, further instructions are given below. If the greater is, then the greater the success rate of matching ∂
i
with ℘
j
will be. Correspondingly, δ
ij
should be greater. If the smaller is, then the smaller the success rate of matching ∂
i
with ℘
j
will be. Correspondingly, δ
ij
should also be smaller. Based on this idea, the total reciprocal difference for ∂
i
towards all the agents of side ℘ (noted as V∂
i
→℘) can be represented by the following:
Therefore, the total reciprocal difference for all the agents of side ∂ towards that of side ℘ (noted as V∂→℘) can be represented by the following:
According to the above analysis, the selection of δ
ij
should make V∂→℘ greatest. Therefore, the objective function is established as the following:
Moreover, the single-objective optimization Model (M-2) can be constructed as follows:
Substitute Equation (13) into Equation (14), and the following is obtained:
Substitute Equation (15) into Equation (13), Equation (12) holds.
With Equation (16), the matching aspiration matrix is set up.
Considering that all the agents of both sides are the same position in most actual cases, then Model (M-1) can be transformed into the following single-objective optimization Model (M-3):
By substituting into Model (M-3), the following optimization Model (M-4) is obtained:
By solving Model (M-4), the “optimal” matching matrix can be obtained. Since Model (M-4) is a single-objective linear programming model, it can be solved by the existing mathematical optimization software.
The procedure of the decision of two-sided matching
In summary, a procedure of the decision of two-sided matching is presented as follows:
Example of matching executives with positions
A matching example between executives and positions was considered, as described in this section. Suppose a group company wants to assign executives to three CEO positions of subsidiary (∂1, ∂2, ∂3). Five executives (℘1, ℘ 2, …, ℘ 5) enter into the final match phase after preliminary screening. The three position experts evaluate five executives from the perspectives of previous work experience, management ability, dynamic learning ability, and the ability to manage change. Then, the interval-valued intuitionistic fuzzy matrix , which is shown in Table 2, is given. The five executives evaluate three positions from the perspectives of strategy of subsidiary, position environment, and personal attitude toward change. Then, the interval-valued intuitionistic fuzzy matrix , which is shown in Table 3, is given. Finally, the board of the group company will determine the ϒ* combined with the above preference information.
To solve the above problem, a simple description of the matching process is given below.
Conclusion
This paper proposed a decision method for solving two-sided matching problems based on interval-valued intuitionistic fuzzy sets considering matching aspirations. The interval-valued intuitionistic fuzzy matrices were transformed into score matrices and a two-sided matching model considering scores and matching aspirations was developed. “Optimal” two-sided matching was obtained by solving the proposed model.
Compared to pre-existing research, the main contribution of this paper lies in the following: (1) The theory of interval-valued intuitionistic fuzzy set was introduced into the field of two-sided matching decisions, which are usually ignored in previous research; (2) The novel interval score was introduced to work with the interval-valued intuitionistic fuzzy set, which can utilize the degree of indeterminacy; (3) This research perspective was from the aspect of matching aspirations, and hence the obtained two-sided matching alternative reflected the matching aspirations of agents; (4) The research of this paper developed a decision theory and method for two-sided matching with interval-valued intuitionistic fuzzy sets.
The limitation of this paper is that it only preliminarily discussed the two-sided matching problem with the preferences of interval-valued intuitionistic fuzzy sets, and the related theory of stable matching under the condition of interval-valued intuitionistic fuzzy sets was not involved.
Hence, the following two courses could be further investigated. First, if the preferences of agents are other intuitionistic fuzzy information, then this kind of two-sided matching decision problem should be further researched. Second, the theory and property of stable matching with interval-valued intuitionistic fuzzy sets should be further explored.
Footnotes
Acknowledgments
This work was partly supported by the NSFC (Project Nos. 71261007, 71261006, 71361021), NSSFC (Project No. 15BGL005), Social Science Fund of Jilin Province (2016JD49) and Natural Science Fund of Jiangxi Province (Project Nos. 20151BAB201026, 20161BAB201025).
