Abstract
In this paper, we define some Einstein operations on Pythagorean trapezoidal uncertain linguistic hesitant fuzzy (PTULHF) set and developed Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein weighted geometric (PTULHFEWG) operator, Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein ordered weighted geometric (PTULHFEOWG) operator and Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein hybrid weighted geometric (PTULHFEHG) operator. Furthermore, we origin ate the relationship between the current aggregation operators and suggested operators and establish many properties of these operators. We apply the proposed aggregation operators to deal with multi-attribute group decision making (MAGDM) problems. Finally, an illustrative example is given to illustrate the decision-making steps and to demonstrate its practicality and effectiveness. We also compare the result of proposed method with existing methods.
Keywords
Introduction
The complexities of decision making problems and decision making situations, it is frequently intricate to communicate attribute values of alternatives by present values. Multi-attribute group decision making (MAGDM) problems widely survive in human social life. In the development of decision-making (DM), decision makers are usually requested to present their evaluation information against a set of alternatives over multiple attributes and then the best one (s) or ranking order result will be obtained by means of some MAGDM methods. Since the classical fuzzy set was anticipated by L.A. Zadeh [2] to express the uncertain and imprecise decision information, a lot of fruitful research achievements have been achieved. Meanwhile, many different forms of extensions of fuzzy sets have been put forward to depict decision-making objects. Intuitionistic fuzzy set (IFS), is generalization of fuzzy sets (FS) developed by Atanassov [1] and discussed the degree of membership degree (MD) and non-membership degree (N-MD). Atanassov [1] also presented several relation and different mathematically operations such as, algebraic product, sum, union, intersection and complement. With the help of membership work, we get data which makes feasible for us to fulfill the conclusion. The requirement of production with uncertainty in existent humanity troubles has been a continuing research experiment that has originated different methodologies and theories. In the study of fuzzy decision making along with their extensions have been discussed the different types of the problems. Fuzzy decision methods have become more and more accepted in decision making for personnel collection. Different decision making approaches have been planned to explain the difficulty. According to Liang [5] partial estimations are then concluded with facts inserted from trusted proficient’s. In accumulation regarding Liang [5] such opinions are supplementary modified by simulating their evaluation with respect to collective influence. If suppositions are not assembling, ordinary aggregation operators are used to choose the paramount alternative. Though, in existent assessment creation, there is a massive covenant of qualitative information that preserve be articulated by linguistic variables (LV), such as “good” and “bad” and so on, and associated to fuzzy numbers, the linguistic variables explain that its membership degree is 1 and its non membership degree is 0. On the establishment of the IFS and the LV set. Wang and Li [9] projected the notion of intuitionistic linguistic sets (ILS) whose fundamentals are intuitionistic linguistic (IL) numbers. As its emergence, the MAGDM method with ILS, particularly the analysis of the IL aggregation technique have obtained progressively consideration. Some intuitionistic linguistic power aggregation operators is proposed by [Liu 13]. Su [10] extensive the idea of order weighted averaging distance operator to intuitionistic linguistic operator.
Zhang et al. [30] proposed an approach to deriving a priority weight vector from an incomplete hesitant fuzzy preference relations (HFPR) using the logarithmic least squares method. Based on the priority weight vector, the consistency index of an incomplete HFPR is defined, which calculates the average deviation between the priority weight vector and all elements of the incomplete HFPR. Zhang et al. [31] also defined group decision making with intuitionistic multiplicative preference relation (IMPR). On this basis, a linear programming-based algorithm is developed to check and improve the consistency of an IMPR. Secondly, discussed the relationships between an IMPR and a normalized intuitionistic multiplicative weight vector. Zhang et al. [32] proposed a novel computational model based on the use of extended linguistic hierarchies, which not only can be used to operate with multi granular linguistic distribution assessments but also can provide interpretable linguistic results to decision makers. Yu Wen et al. [33] proposed a new method to deal with multi-criteria group decision making problems with unbalanced hesitant fuzzy linguistic term sets. The uncertain linguistic hesitant fuzzy set theory is a useful tool to deal with uncertainty in decision-making problems, which is proved by many scientific papers. This approach represents the situation in which different membership functions are considered possible in respect of decision situation. The elements in HFLSs are called hesitant fuzzy linguistic numbers (HFLNs). That is to say, for one object, an HFLS is reduced to an HFLN, which can be considered as a special case of HFLSs. For example < s2, (0.3,0.4,0.5)>is an HFLNs and 0.3, 0.4, and 0.5 are the possible membership degrees to the linguistic terms. HFLSs have enabled great progress in describing linguistic information and to some extent may be considered an innovative construct. The main advantage of HFLSs is that they can describe two fuzzy attributes of an object: a linguistic term and a hesitant fuzzy element. The former provides an evaluation value, such as “excellent’‘ or “good.” The latter describes the hesitancy for the given evaluation value and denotes the membership degrees associated with the specific linguistic term.
In some practical multiattribute group decision making problems, the related criteria may be at different priority levels. For instance, a young couple wants to choose a toy for their child, the criteria of the toy they will consider are safety and price; obviously, the criteria safety has a higher priority than price. Aggregation operator plays a crucial role in the process of information fusion. In real life, the criteria sometimes have different priority levels. For example, safety has a higher priority than price when a couple chooses a toy for their child. Xiao [11] discussed the intuitionist linguistic suggest order weighted averaging operator, and pre-meditated its function in financial decision making problems. Liu and Jin [12] further planned the intuitionistic uncertain linguistic variables (IULVs) by extending LV and defined some basic operational laws of intuitionistic uncertain linguistic variables. Since linguistic variables are the unique cases of the uncertain linguistic variables, the IULVs are more general than the intuitionistic linguistic variables (ILS). P Liu et al. [14] developed the idea of linguistic fuzzy and discussed many operators in this field. In 2013, Yager [18, 19] constructed the idea of Pythagorean fuzzy set (PFS) differentiated by a MD and N-MD degree, which satisfies the provision that the square sum of its MD and N-MD degree is less than or equivalent to 1. Yager [19] gave an example to state of this condition, a DM gives his maintain for MD of an alternative as
The proposed operators are the advanced version of the already existing operators, treating the uncertainty problems in more accurate way. A variety of the problems can be addressed using these operators., which may not be covered by the existing literature. Based on the above analysis in this paper we consider Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein aggregation operators. From the above literature review the geometric Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein aggregation operator is not define. Therefore we develop a series of Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein aggregation operators, including the Pythagorean trapezoidal uncertain linguistic fuzzy Einstein weighted geometric (PTULHFEWG) operator, Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein ordered weighted geometric (PTULHFEOWG) operator and Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein hybrid geometric(PTULHFEHG) operator. We also develop the score and accuracy functions for these aggregation operators. Further, ranking order with the alternative highly depends on the weights of Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein numbers, so choosing the weight vector is an important task. In this paper, the unknown weight vector of the Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein numbers is determined by using the aggregation operators. The main contributions of this work are summarized as below: To overcome the shortcomings, some new operation laws for Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein numbers and based on it, some series of weighted, ordered weighted and hybrid weighted geometric aggregation operators have been proposed. The various desirable relations between them have been investigated in details. The proposed operators introduce a new representation by considering the dependency between the degrees of the membership and non-membership functions during the aggregation process. Furthermore, based on it, a multi-criteria decision-making approach presented for solving the decision-making problems.
In this paper we develop the following sections; In Section 2, we briefly assess various necessary notions of intuitionistic fuzzy numbers, Pythagorean fuzzy numbers, trapezoidal fuzzy numbers, and Einstein operations on Pythagorean trapezoidal uncertain linguistic fuzzy numbers. In Section 3, we suggest some Pythagorean trapezoidal uncertain linguistic hesitant fuzzy aggregation operators based on Einstein operations, such as Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein weighted geometric (PTULHFEWG) operator, Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein ordered weighted geometric (PTULHFEOWG) operator and Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein hybrid geometric (PTULHFEHG) operator. In Section 4, we develop a MAGD method based on the proposed operators under Pythagorean trapezoidal uncertain linguistic hesitant fuzzy environment. In Section 5, we give numerical example. In Section 6, we compare the result with existing methods. Concluding remarks are completed in Section 7.
Preliminaries
In this section, we provide some basic definitions and results of intuitionistic uncertain linguistic set, intuitionistic trapezoidal fuzzy numbers, Pythagorean fuzzy numbers and Pythagorean trapezoidal fuzzy numbers.
Now we define the definition of Yager concept of Pythagorean fuzzy sets and some basic properties
For each PFS, U in L,
Now we define the definition of Shakeel et al. concept of Pythagorean trapezoidal fuzzy numbers and some basic properties
In the following, we define some operation of Pythagorean trapezoidal uncertain linguistic (PTUL) fuzzy numbers, based on Einstein operational laws as follows;
The assumption of aggregation operators has an significant function since in the establishment of fuzzy set theory. Einstein operations is a class of assorted t-norms and t-conorms families [26, 27] can be utilized to realize the corresponding intersections and unions of IFSs. Pythagorean Einstein operations consists of the Pythagorean Einstein product and the Pythagorean Einstein sum, respectively, defined as follows.
In the following, we define some operation of Pythagorean trapezoidal uncertain linguistic hesitant fuzzy (PTULHF) numbers, based on Einstein operational laws as follows;
We define Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein aggregation operators, based on the above Einstein operational laws of PTULHFENs, we will investigate the Pythagorean trapezoidal uncertain linguistic hesitant fuzzy information aggregation operators and give the Definitions of some aggregation operators with the Pythagorean trapezoidal uncertain linguistic hesitant fuzzy numbers based on Einstein operational laws as follows. Let Ω be the set of Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein numbers.
Pythagorean trapezoidal uncertain linguistic hesitant fuzzy einstein geometric aggregation operators
where w = (w1, w2, . . . w
n
)
T
is the weighting vector of
By Definition 11, we have
(2) (Boundray) Let
(3) (Monotonicity) Let
Let
Since
where (σ (1) , σ (2) , . . . , σ (n)) is a permutation of (1, 2 . . . , n), such that,
(Idmpotency) If for all
(Boundary) Let
(Monotonicity) Let
(Commutativity) Let
where
We shall propose Pythagorean trapezoidal uncertain linguistic fuzzy Einstein hybrid geometric (PTULHFEHG) operator as follows.
Similarly as proof of Theorem 3, it is omitted here.
In this section, we apply the proposed aggregation operators to develop an approach for dealing with multiple attribute group decision making problems under the Pythagorean trapezoidal uncertain linguistic hesitant fuzzy environment.
Algorithm: For a group decision making problem. Consider A = {A1, A2, . . . , A
m
} be a set of alternatives, C = {C1, C2, . . . , C
n
} be a set of attributes/characteristic, and w = (w1, w2, . . . , w
n
)
T
is the weighting vector of the attributes such that w
j
∈ [0, 1] and
is Pythagorean trapezoidal uncertain linguistic hesitant fuzzy number provided by decision makers m
k
∈ M, such that
In the following, we apply the PTULHFEWG and PTULHFEHG operators to develop an approach to deal with multiple attribute group decision making problems, when decision information is this method consists of the following steps:
w = (w1, w2, . . . , w
n
)
T
is the associated vector of PTULHFEHG operator such that w
j
∈ [0, 1] and
In this section, we developed a numerical application of proposed method and solved the surface irrigation problem. Consider that the water flows and spreads over the surface of the land. Varied quantities of water are allowed on the fields at different times. Therefore, flow of water under surface irrigation comes under wobbly flow. Consequently, it is very difficult to understand the hydraulics of surface irrigation. However suitable and efficient surface irrigation system can be espoused after taking into consideration different factors which are involved in the hydraulics of surface irrigation.
Therefore, we are going to present an illustrative example of the new approach in a decision making problem. We analyze that the ratio of water flows of the land was increasing day-by-day in Pakistan, therefore the government of Pakistan wanted to control the ratio of this problem. For this purpose they consider four possible alternatives A i (i = 1, 2, 3, 4) such that,
A1: Surface slope of the field
A2: Roughness of the field surface
A3: Depth of water to be applied
A4: Field resistance to erosion
To evaluate these alternatives a group of committee take a decision about the best surface land according to the following four attributes C j (j = 1, 2, 3, 4). Let w = (0.4, 0.3, 0.2, 0.1) are weighting vector of the attributes C j (j = 1, 2, 3, 4). such that,
C1: It assists in storing required amount of water in the root-zone-depth
C2: It reduces the wastage of irrigation water from the field in the form of run-off water
C3: It reduces the soil erosion to minimum.
C4: It does not avert use of machinery for land preparation, cultivation and harvesting.
The experts of the government evaluate and offer their own opinions regarding the results obtained with each alternative, suppose the weights of the experts are given as λ = (0.1, 0.2, 0.3, 0.4). As the environment is very uncertain, the group of experts needs to assess the available information by using PTULHFNs. The expected results given in the form of PTULHFNs depending on the characteristic C
j
and the alternative A
i
are shown Tables 1–4. Such that,
R(1) Decision matrix of expert -1
R(1) Decision matrix of expert -1
R(2). Decision matrix of expert -2
R(3). Decision matrix of expert -3
R(4). Decision matrix of expert -4
Step 5. Now we arrange the scores of all alternatives such as, A2 > A1 > A3 > A4. Thus the most wanted alternative is A2.
In way to verify the sagacity and efficiency of the proposed approach, a comparative study is developed with intuitionistic trapezoidal fuzzy numbers W. Jianqiang et al. 2009, Pythagorean trapezoidal fuzzy numbers Fasil et al. 2019 and Pythagorean fuzzy aggregation operator Zhenming et al. 2016, to related expressive example shown in Tables 5–7.
Z(1)
Z(1)
Comparison analysis with Pythagorean trapezoidal fuzzy sets
Comparison analysis with existing methods
Comparison analysis with existing methods
We have given the comparison analysis of the proposed aggregation operators with intuitionistic trapezoidal fuzzy aggregation operators, Pythagorean trapezoidal fuzzy aggregation operators and Pythagorean fuzzy aggregation operator. It is noted that the ranking results obtained by proposed method and existing methods are very different. From the comparison analysis, we concluded that our proposed aggregation operator is much better in finding the optimal solutions. Based on these analysis the proposed aggregation operator is more reliable and effective in real life problem.
Conclusions
In this paper, we introduced the initiative of Pythagorean trapezoidal uncertain linguistic hesitant Einstein fuzzy sets. We have defined their basic properties and develop some operational laws for Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein numbers. We have discussed some new types of aggregation operators for Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein numbers consists of Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein weighted geometric (PTULHFEWG) operator, Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein ordered weighted geometric (PTULHFEOWG) operator and Pythagorean trapezoidal uncertain linguistic hesitant fuzzy Einstein hybrid geometric (PTULHFEHG) operators. Moreover, we apply these aggregation operators to develop an approach to MAGDM with PTULF. Finally, an illustrative example has been constructed to show the proposed MAGDM method. Our proposed method is different from all the previous techniques for group decision making. So it is efficient and feasible for real-world decision making applications. These operators can be applied to many other fields, such as data mining, symmetric aggregation operator, Dombi aggregation operator, pattern recognition and TODIM-TOPSIS method which may be the possible topic for the future research.
Footnotes
Appendix 1
(3) Let n be any positive integer and
By using mathematical induction we prove that Equation (9) holds for all positive integers n. First, we show that Equation (9) holds for n = 2. Since
Therefore, the Equation (9) holds for n = 2. If Equation (9) holds for n = k. Then,
When n = k + 1, we have
Hence Equation (9) holds for n = k + 1, therefore Equation (9) holds for all n.
(4) Let m be any positive integer and
By using mathematical induction we prove that Equation (9) holds for all positive integers m. First, we show that Equation (9) holds for m = 2.Since
Therefore, the Equation (9) holds for m = 2. If Equation (9) holds for m = k, such that
Then, we have
Hence Equation (9) holds for m = k + 1. Therefore Equation (9) holds for all m.
By the Einstein operational laws of PTULHF numbers satisfies the following properties;
Appendix 2
(2) By Einstein operational laws (2) in Definition 9, we have
Let
(3) Since
Appendix 3
(1) We first prove that Equation (11) holds for n = 2. Since
(2) If Equation (11) holds for n = k, that is
Then, by the Einstein operational law (3) of Definition 9, we have
Acknowledgments
The authors extended their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work through Research Group Program under grant number R-G.P2/52/40.
