![]() | Computer Modeling in Engineering & Sciences | ![]() |
DOI: 10.32604/cmes.2022.018267
ARTICLE
Sine Trigonometry Operational Laws for Complex Neutrosophic Sets and Their Aggregation Operators in Material Selection
1Sacred Heart College (Autonomous), Tamil Nadu, 635601, India
2Maejo University, Chiang Mai, 50290, Thailand
3Phuket Rajabhat University, Phuket, 83000, Thailand
4Rajamangala University of Technology Suvarnabhumi, Nonthaburi, 11000, Thailand
*Corresponding Author: N. Boonsatit. Email: nattakan.b@rmutsb.ac.th
Received: 11 July 2021; Accepted: 07 September 2021
Abstract: In this paper, sine trigonometry operational laws (ST-OLs) have been extended to neutrosophic sets (NSs) and the operations and functionality of these laws are studied. Then, extending these ST-OLs to complex neutrosophic sets (CNSs) forms the core of this work. Some of the mathematical properties are proved based on ST-OLs. Fundamental operations and the distance measures between complex neutrosophic numbers (CNNs) based on the ST-OLs are discussed with numerical illustrations. Further the arithmetic and geometric aggregation operators are established and their properties are verified with numerical data. The general properties of the developed sine trigonometry weighted averaging/geometric aggregation operators for CNNs (ST-WAAO-CNN & ST-WGAO-CNN) are proved. A decision making technique based on these operators has been developed with the help of unsupervised criteria weighting approach called Entropy-ST-OLs-CNDM (complex neutrosophic decision making) method. A case study for material selection has been chosen to demonstrate the ST-OLs of CNDM method. To check the validity of the proposed method, entropy based complex neutrosophic CODAS approach with ST-OLs has been executed numerically and a comparative analysis with the discussion of their outcomes has been conducted. The proposed approach proves to be salient and effective for decision making with complex information.
Keywords: Complex neutrosophic sets (CNSs); sine trigonometric operational laws (ST-OLs); aggregation operator; entropy; CODAS; material selection; decision making
One of the complex problems in all types of industries/companies is making decisions based on ambiguous information. As a consequence, the concept of fuzzy set theory has been employed to deal with this type of situation or problem. Zadeh [1] first proposed the concept of fuzzy subsets in 1965. It has sparked numerous significant outcomes in the scientific community, which have been replicated in modern applications, particularly in decision-making and artificial intelligence. In addition, different researchers have extended the core idea of fuzzy sets to handle different types of uncertainty, and the extended notions of fuzzy sets include intuitionistic fuzzy sets (IFSs) [2], Pythagorean fuzzy sets (PFSs) [3], Fermatean fuzzy sets (FFSs) [4], Neutrosophic sets (NSs) [5], and Spherical fuzzy sets (SFSs) [6] among others and each of them addresses the problem of uncertainty in a unique way. Based on these notions, various multi criteria decision making (MCDM) approaches are available in the literature like weighted sum method (WSM), weighted product method (WPM), the multiple criteria optimization compromise solution (VIKOR), the technique for order performance by similarity to the ideal solution (TOPSIS), the Weighted Aggregates Sum Product Assessment (WASPAS), COmbinative Distance-Based ASsessment (CODAS), and the Evaluation Based on Distance from Average Solution (EDAS), etc., MCDM is a technique for selecting the best option from a set of alternatives and neutrosophic sets have found wide scope in such techniques. Edalatpanah established a new model of data envelopment analysis based on triangular neutrosophic numbers [7]. And also neutrosophic approach have been implemented to data envelopment analysis with undesirable outputs by Mao et al. [8]. A new ranking function of triangular neutrosophic number [9] and systems of neutrosophic linear equations are introduced by Edalatpanah [10].
Complex fuzzy sets (CFSs) are a significant research area of investigation in fuzzy logic. It was proposed by Ramot et al. [11,12]. CFSs use a complex membership function to handle uncertainty with periodicity which takes complex values within the complex unit circle. Clearly, the complex memership function M=μeiα of a CFS comprises two terms named amplitude term μ and phase term α which lie in the intervals [0,1] and [0,2π], respectively. The phase term accounts for the periodicity of the data and distinguishes CFSs from the traditional models of fuzzy set theory. CFSs and Complex Fuzzy Logic (CFL) have been utilized to develop accurate and efficient time series forecasting models [13,14], image processing [15], etc. The concept of CFSs, has been further extended to complex intuitionistic fuzzy sets (CIFSs) [16], complex Pythagorean fuzzy sets (CPFSs) [17], complex neutrosophic sets (CNSs) [18] and so on and also it is evident from the literature that notable research have been carried out in complex fuzzy sets scenario. Recently, Xu et al. [19] introduced an extended EDAS method with a single-valued complex neutrosophic set and its application in green supplier selection. Complex neutrosophic generalized dice similarity measures have been developed by Ali et al. [20]. Also, another MCDM model called a soft set based VIKOR is developed based on CNSs by Manna et al. [21]. Some of complex hybrid weighted averaging operators are introduced for decision making in [22]. Aggregating the fuzzy information plays an important role in decision theory and it is involved in majority of MCDM methods.
In addition operational laws also play a vital role in aggregation process. Also it is evident from the literature that various operational laws are available. Gou et al. [23] used new type of operational laws for IFSs. Then, Li et al. [24] introduced the logarithmic operational laws for IFSs in order to aggregate information. Later, Garg et al. [25] introduced a new logarithmic operational laws for single valued neutrosophic number which yields application in multi attribute decision making. Also, Ashraf et al. [26] used logarithmic hybrid aggregation operators for single valued neutrosophic sets. In continuation, Garg et al. [27] have presented some new exponential, logarithmic, and compensative exponential of logarithmic operational laws for complex intuitionistic fuzzy (CIF) numbers based on t-norm and co-norm. Garg also utilized the logarithmic operational laws for PFSs in [28]. Further, Nguyen et al. [29] developed exponential similarity measures for Pythagorean fuzzy sets and their application in pattern recognition. Haque et al. [30] utilized exponential operational laws for generalized SFSs. Another novel concept of neutrality operational laws have been introduced by Garg et al. [31] for q-rung orthopair fuzzy sets and Pythagorean fuzzy geometric aggregation operators [32]. Also, Garg extended the new exponential operation laws for q-rung orthopair fuzzy sets in [33].
Sine trigonometric operational laws were introduced by Garg [34]. The main advantage of sine trigonometric function is that it accounts for the periodicity and it is symmetric about the origin. Thus it satisfies the expectations of the decision-maker over the multi-time phase parameters. Garg [35] introduced a novel trigonometric operation based q-rung ortho pair fuzzy aggregation operators and he also extended these operational laws to Pythagorean fuzzy information [36]. Abdullah et al. [37] developed an approach of ST-OLs for picture fuzzy sets. Ashraf et al. [38] utilized the concept of single valued neutrosophic sine trigonometric aggregation operators for hydrogen power plant selection and further they implemented these operational laws for spherical fuzzy environment in [39]. MCDM methods namely TOPSIS and VIKOR have been developed based on ST-OLs by Qiyas et al. [40,41]. From the literature, it is clear that ST-OLs play predominant role in aggregation operators (AOs). Through this motivation and considering the advantage of ST-OLs, some new ST-OLs for CNSs must be established and their behaviour in complex scenario needs to be studied. Hence, this paper aims to modify sine trigonometric operational laws for complex neutrosophic sets and implement them in complex decision making method for material selection. So, the main objective of this paper can be described as follows:
(i). To present the ST-OLs for CNSs
(ii). To obtain some of the distance measure for complex neutrosophic sets based on ST-OLs
(iii). To develop an MCDM technique with the help of the proposed aggregation operators
(iv). To demonstrate an entropy technique based on ST-OLs for CNNs in order to attain complex weights of criteria
(v). To give an application of the proposed MCDM method in material selection in an industry
(vi). Finally, to present the validation of the developed method with existing CODAS approach
The organization of the paper is the following; We review the basic concept of NSs in the second section of the paper. In Section 3, we explore the operations of enhanced ST-OLs for NSs. These ST-OLs have been extended to CNSs in Section 4, including subtraction and distance measurement of ST-OLs for CNSs. In Section 5, we develop AOs and prove their properties for ST-OLs of CNSs. In Section 6, an MCDM approach has been explained in detailed steps with entropy technique for criteria weights. The proposed MCDM approach is used to provide an application for material selection in Section 7. The validation and discussion of the study is carried out in Section 8. Finally, the paper is concluded in Section 9 with direction for further research.
Some of the basic concepts of neutrosophic sets (NSs) with their operations are discussed here.
Definition 2.1 [1] A fuzzy set ˜F defined on a universe of discourse ∗ℜ has the form: ˜F={⟨ξ˜F(˙r)⟩|˙r∈∗ℜ}, where ξ˜F(˙r):∗ℜ→[0,1]. Here ξ˜F(˙r) denotes the membership function of each ˙r.
Definition 2.2 [2] An intuitionistic fuzzy set ~IF is defined as a set of ordered pairs over a universal set ∗ℜ and is given by ~IF={⟨(ξ~IF(˙r),ψ~IF(˙r))⟩|˙r∈∗ℜ}, where ξ~IF(˙r):∗ℜ→[0,1],ψ~IF(˙r):∗ℜ→[0,1] with the condition ξ~IF(˙r)+ψ~IF(˙r)≤1 for each element ˙r∈∗ℜ. Here the membership and non-membership functions are denoted as ξ~IF(˙r) and ψ~IF(˙r), respectively.
Definition 2.3 [5] Let ∗ℜ be a universe of discourse or a non empty set. Any object in the neutrosophic set ~NF has the form ~NF={⟨μ~NF(˙r),σ~NF(˙r),γ~NF00(˙r)⟩|˙r∈∗ℜ}, where μ~NF(˙r), σ~NF(˙r) and γ~NF(˙r) represent the degree of truth membership, the degree of indeterminacy and the degree of false membership respectively of each element ˙r∈∗ℜ to the set ~NF and it is defined as ~NF={⟨μ~NF(˙r),σ~NF(˙r),γ~NF(˙r)⟩|˙r∈∗ℜ}, where μ~NF(˙r),σ~NF(˙r),γ~NF(˙r):∗ℜ→[0,1] such that 0≤μ~NF(˙r)+σ~NF(˙r)+γ~NF(˙r)≤3.
Definition 2.4 [5] Let ~NF=˙r:⟨μ~NF(˙r),σ~NF(˙r),γ~NF(˙r)⟩ , ~NF1=˙r:⟨μ~NF1(˙r),σ~NF1(˙r),γ~NF1(˙r)⟩ and ~NF2=˙r:⟨μ~NF2(˙r),σ~NF2(˙r),γ~NF2(˙r)⟩ be three neutrosophic numbers (NNs) and let ¨w be any scalar. Then
~NFc=⟨γ~NF(˙r),σ~NF(˙r),μ~NF(˙r)⟩~NF1∩~NF2=⟨min(μ~NF1(˙r),μ~NF2(˙r)),max(σ~NF1(˙r),σ~NF2(˙r)),max(γ~NF1(˙r),γ~NF2(˙r))⟩~NF1∪~NF2=⟨max(μ~NF1(˙r),μ~NF2(˙r)),min(σ~NF1(˙r),σ~NF2(˙r)),min(γ~NF1(˙r),γ~NF2(˙r))⟩~NF1⊕~NF2=⟨μ~NF1(˙r)+μ~NF2(˙r)−μ~NF1(˙r).μ~NF2(˙r),σ~NF1(˙r).σ~NF2(˙r),γ~NF1(˙r).γ~NF2(˙r)⟩~NF1⊗~NF2=⟨μ~NF1(˙r).μ~NF2(˙r),σ~NF1(˙r)+σ~NF2(˙r)−σ~NF1(˙r).σ~NF2(˙r),γ~NF1(˙r)+γ~NF2(˙r)−γ~NF1(˙r).γ~NF2(˙r)⟩¨w.~NF=⟨1−(1−μ~NF(˙r))¨w,(σ~NF(˙r))¨w,(γ~NF(˙r))¨w⟩(~NF)¨w=⟨(μ~NF(˙r))¨w,1−(1−σ~NF(˙r))¨w,1−(1−γ~NF(˙r))¨w⟩Definition 2.5 Let ~NF1=˙r:⟨μ~NF1(˙r),σ~NF1(˙r),γ~NF1(˙r)⟩ and ~NF2=˙r:⟨μ~NF2(˙r),σ~NF2(˙r),γ~NF2(˙r)⟩ be two NNs. Then
i. ~NF1⊆~NF2 if and only if μ~NF1(˙r)≤μ~NF2(˙r) , σ~NF1(˙r)≥σ~NF2(˙r) , γ~NF1(˙r)≥γ~NF2(˙r) for each (˙r)∈∗ℜ
ii. ~NF1⊆~NF2 if and only if ~NF1⊆~NF2 and ~NF1⊇~NF2
Definition 2.6 Let ~NF=˙r:⟨μ~NF(˙r),σ~NF(˙r),γ~NF(˙r)⟩ , ~NF1=˙r:⟨μ~NF1(˙r),σ~NF1(˙r),γ~NF1(˙r)⟩ and ~NF2=˙r:⟨μ~NF2(˙r),σ~NF2(˙r),γ~NF2(˙r)⟩ be three NNs. Then the score and accuracy functions of NNs are defined as follows:
(1) Score(~NF)=μ~NF(˙r)−σ~NF(˙r)−γ~NF(˙r)
(2)Accuracy(~NF)=μ~NF(˙r)+σ~NF(˙r)+γ~NF(˙r)
Also, the following conditions hold good.
(1) If Score(~NF1)>Score(~NF2) then ~NF1>~NF2
(2) If Score(~NF1)<Score(~NF2) then ~NF1<~NF2
(3) If Score(~NF1)=Score(~NF2) then ~NF1=~NF2
(4) If Accuracy(~NF1)>Accuracy(~NF2) then ~NF1>~NF2
(5) If Accuracy(~NF1)<Accuracy(~NF2) then ~NF1<~NF2
(6) If Accuracy(~NF1)=Accuracy(~NF2) then ~NF1=~NF2
3 Sine Trigonometry Operational Law (STOL) for Neutrosophic Sets
First, the STOL [34] are applied to neutrosophic sets and the boundary conditions are verified.
Definition 3.1 Let the neutrosophic numbers (NNs) be ~NF=˙r:⟨μ~NF(˙r),σ~NF(˙r),γ~NF(˙r)⟩. Then, the sine trigonometric operational laws of NNs are defined as follows:
sin(~NF)={⟨sin(π2.μ~NF(˙r)),sin2(π2.σ~NF(˙r)),2sin2(π4.γ~NF(˙r))⟩|˙r∈∗ℜ}(1)
From the above STOL of NNs, it is evident that the sin(~NF) is also NNs. And it satisfies the following condition of neutrosophic set as the degree of truth, indeterminacy, and falsity of NS are defined, respectively
sin(π2.μ~NF(˙r)):∗ℜ→[0,1] such that
0≤sin(π2.μ~NF(˙r))≤1,
sin2(π2.σ~NF(˙r)):∗ℜ→[0,1] such that 0≤sin2(π2.σ~NF(˙r))≤1,
2sin2(π4.γ~NF(˙r)):∗ℜ→[0,1] such that 0≤2sin2(π4.γ~NF(˙r))≤1,
Also, 0≤⟨sin(π2.μ~NF(˙r))+sin2(π2.σ~NF(˙r))+2sin2(π4.γ~NF(˙r))⟩≤3. Therefore, STOL of NNs are also NNs, a fact which is also affirmed by Fig. 1.
Then we discuss the fundamental operations on sine trigonometric neutrosophic numbers (STNNs) and their properties.
Figure 1: This is a graph of STOLs of NNs
Definition 3.2 Let ~NF=˙r:⟨μ~NF(˙r),σ~NF(˙r),γ~NF(˙r)⟩, ~NF1=˙r:⟨μ~NF1(˙r),σ~NF1(˙r),γ~NF1(˙r)⟩ and ~NF2=˙r:⟨μ~NF2(˙r),σ~NF2(˙r),γ~NF2(˙r)⟩ be neutrosophic numbers (NNs) and let ¨w be any scalar. Then
• Complement of ~sin(NF):
~sin(NF)c=⟨2sin2(π4.γ~NF(˙r)),sin2(π2.σ~NF(˙r)),sin(π2.μ~NF(˙r))⟩• Intersection of ~sin(NF1) and ~sin(NF2):
~sin(NF1)∩~sin(NF2)=⟨min(sin(π2.μ~NF1(˙r)),sin(π2.μ~NF2(˙r))),max(sin2(π2.σ~NF1(˙r)),sin2(π2.σ~NF1(˙r))),max(2sin2(π4.γ~NF1(˙r)),2sin2(π4.γ~NF2(˙r)))⟩• Union of ~sin(NF1) and ~sin(NF2):
~sin(NF1)∩~sin(NF2)=⟨max(sin(π2.μ~NF1(˙r)),sin(π2.μ~NF2(˙r))),min(sin2(π2.σ~NF1(˙r)),sin2(π2.σ~NF1(˙r))),min(2sin2(π4.γ~NF1(˙r)),2sin2(π4.γ~NF2(˙r)))⟩• Algebric sum of ~sin(NF1) and ~sin(NF2):
~sin(NF1)⊕~sin(NF2)=⟨sin(π2.μ~NF1(˙r))+sin(π2.μ~NF2(˙r))−sin(π2.μ~NF1(˙r)).sin(π2.μ~NF2(˙r)),sin2(π2.σ~NF1(˙r)).sin2(π2.σ~NF1(˙r)),2sin2(π4.γ~NF1(˙r)).2sin2(π4.γ~NF2(˙r))⟩• Algebric product of ~sin(NF1) and ~sin(NF2):
~sin(NF1)⊗~sin(NF2)=⟨sin(π2.μ~NF1(˙r)).sin(π2.μ~NF2(˙r)),sin2(π2.σ~NF1(˙r))+sin2(π2.σ~NF2(˙r))−sin2(π2.σ~NF1(˙r)).sin2(π2.σ~NF2(˙r)),2sin2(π4.γ~NF1(˙r))+2sin2(π4.γ~NF1(˙r))−2sin2(π4.γ~NF1(˙r)).2sin2(π4.γ~NF1(˙r))⟩• Scalar product of ~sin(NF):
¨w.~sin(NF)=⟨1−(1−sin(π2.μ~NF1(˙r)))¨w,(sin2(π2.σ~NF1(˙r)))¨w,(2sin2(π4.γ~NF1(˙r)))¨w⟩• Power of ~sin(NF):
(~sin(NF))¨w=⟨(sin(π2.μ~NF1(˙r)))¨w,1−(1−sin2(π2.σ~NF1(˙r)))¨w,1−(1−2sin2(π4.γ~NF1(˙r)))¨w⟩Definition 3.3 Let ~sin(NF1) and ~sin(NF2) be two sine trigonometric neutrosophic numbers. Then
i. ~sin(NF1)⊆~sin(NF2) if and only if sin(π2.μ~NF1(˙r))≤sin(π2.μ~NF2(˙r)), sin2(π2.σ~NF1(˙r))≥sin2(π2.σ~NF2(˙r)), 2sin2(π4.γ~NF1(˙r))≥2sin2(π4.γ~NF2(˙r)) for each (˙r)∈∗ℜ
ii. ~sin(NF1)=~sin(NF2) if and only if ~sin(NF1)⊆~sin(NF2) and ~sin(NF1)⊇~sin(NF2)
Definition 3.4 Let ~NF=˙r:⟨μ~NF(˙r),σ~NF(˙r),γ~NF(˙r)⟩ be a neutrosophic number. Then the score and accuracy functions of STOL of NNs are defined as follows:
1. Score(sin(~NF))=sin(π2.μ~NF(˙r))−sin2(π2.σ~NF(˙r))−2sin2(π4.γ~NF(˙r))
2. Accuracy(sin(~NF))=sin(π2.μ~NF(˙r))+sin2(π2.σ~NF(˙r))+2sin2(π4.γ~NF(˙r))
Here the score and accuracy range values of STOLs of NNs are discussed in pictorial representation in the following Figs. 2 and 3 when the membership values of μ~NF(˙r), σ~NF(˙r), γ~NF(˙r) are equal.
Figure 2: This is a graph of score range values of STOLs of NNs
Figure 3: This is a graph of accuracy range values of STOLs of NNs
4 Sine Trigonometry Operational Laws (STOLs) for Complex Neutrosophic Sets (CNSs)
First, we see some basic concepts of complex neutrosophic sets and their operations.
Definition 4.1 [18] A complex neutrosophic set ~cNF, is represented by truth membership function (μ~NF(˙r).ej2πΘ(μ~NF(˙r))), an indererminacy membership function (σ~NF(˙r).ej2πΘ(σ~NF(˙r))) and a falsity membership function (γ~NF(˙r).ej2πΘ(γ~NF(˙r))) that take complex values for any ˙r∈∗ℜ. The three membership values and their sum may all lie within the unit circle in the complex plane and this is of the following form: ~cNF(˙r)=⟨μ~NF(˙r).ej2πΘ(μ~NF(˙r)),σ~NF(˙r).ej2πΘ(σ~NF(˙r)),γ~NF(˙r).ej2πΘ(γ~NF(˙r))⟩ where j=√−1 and μ~NF(˙r),σ~NF(˙r),γ~NF(˙r) are amplitude terms whose values lie in [0,1], and the phase terms are Θ(μ~NF(˙r)),Θ(σ~NF(˙r)),Θ(γ~NF(˙r))∈[0,1] such that 0≤μ~NF(˙r)+σ~NF(˙r)+γ~NF(˙r)≤3 and 0≤Θ(μ~NF(˙r))+Θ(σ~NF(˙r))+Θ(γ~NF(˙r))≤3. The modulus of μ~NF(˙r).ej2πΘ(μ~NF(˙r)) is μ~NF(˙r), also denoted by |μ~NF(˙r)|. Similarly, the modulus of σ~NF(˙r).ej2πΘ(σ~NF(˙r)),γ~NF(˙r).ej2πΘ(γ~NF(˙r)) are σ~NF(˙r),γ~NF(˙r), respectively. The set builder form of the complex neutrosophic set ~cNF is represented as ~cNF(˙r)={⟨μ~NF(˙c).ej2πΘ(μ~NF(˙r)),σ~NF(˙c).ej2πΘ(σ~NF(˙r)),γ~NF(˙r).ej2πΘ(γ~NF(˙r))⟩˙r∈∗ℜ} where, μ~NF(˙c).ej2πΘ(μ~NF(˙r)):∗ℜ→{μ~NF(˙c).ej2πΘ(μ~NF(˙r))∈C,|μ~NF(˙c).ej2πΘ(μ~NF(˙r))|≤1},σ~NF(˙c).ej2πΘ(σ~NF(˙r)):∗ℜ→{σ~NF(˙c).ej2πΘ(σ~NF(˙r))∈C,|σ~NF(˙c).ej2πΘ(σ~NF(˙r))|≤1},γ~NF(˙r).ej2πΘ(γ~NF(˙r)):∗ℜ→{γ~NF(˙r).ej2πΘ(γ~NF(˙r))∈C,|γ~NF(˙r).ej2πΘ(γ~NF(˙r))|≤1}, such that
|μ~NF(˙c).ej2πΘ(μ~NF(˙r))+σ~NF(˙c).ej2πΘ(σ~NF(˙r))+γ~NF(˙r).ej2πΘ(γ~NF(˙r))|≤3.
Example 4.1 Let ∗ℜ={∗ℜ1,∗ℜ2,∗ℜ3} be a universe of discourse. Then, ~cNF(˙r) is a complex neutrosophic set in ∗ℜ given by
~cNF(˙r)={(0.5ej2π(0.7),0.6ej2π(0.5),0.5ej2π(0.4))˙r1+(0.5ej2π(0.7),0.7ej2π(0.5),0.2ej2π(0.4))˙r2+(0.8ej2π(0.7),0.4ej2π(0.6),0.6ej2π(0.5))˙r3}.The STOLs have been introduced for complex neutrosophic sets and their boundary conditions are verified.
Definition 4.2 Let ~cNF(˙r) be a complex neutrosophic number (CNN).
~cNF(˙r)=˙r:⟨μ~NF(˙r).ej2πΘ(μ~NF(˙r)),σ~NF(˙r).ej2πΘ(σ~NF(˙r)),γ~NF(˙r).ej2πΘ(γ~NF(˙r))⟩Then, the sine trigonometric operational law of CNNs (ST-OLs-CNNs) is defined as follows:
sin(~cNF(˙r))={⟨sin(π2.μ~NF(˙r)).ej2π(sin(π2.Θ(μ~NF(˙r)))),sin2(π2.σ~NF(˙r)).ej2π(sin2(π2.Θ(σ~NF(˙r)))),2sin2(π4.γ~NF(˙r)).ej2π(2sin2(π4.Θ(γ~NF(˙r))))⟩|˙r∈∗ℜ}(2)
From the above STOL of CNNs, it is evident that the sin(~cNF(˙r)) is also a CNN. And it satisfies the following condition of CNSs as the degree of truth, indeterminacy, and false of complex neutrosophic sets are defined, respectively.
sin(π2.μ~NF(˙r)).ej2π(sin(π2.Θ(μ~NF(˙r)))):∗ℜ→[C]suchthat0≤|sin(π2.μ~NF(˙r)).ej2π(sin(π2.Θ(μ~NF(˙r))))|≤1
sin2(π2.σ~NF(˙r)).ej2π(sin2(π2.Θ(σ~NF(˙r)))):∗ℜ→[C]suchthat0≤|sin2(π2.σ~NF(˙r)).ej2π(sin2(π2.Θ(σ~NF(˙r))))|≤1
Also,
Example 4.2 Let
Then, the sine trigonometric operational law of CNNs (ST-OLs-CNNs) is also a CNN. We describe the function as follows:
Also, the modulus of ST-OLs of CNNs is listed below and it is observed that the sum of values is less than or equal to three.
Then we discuss the fundamental operations on sine trigonometric operational laws of CNNs and their properties.
Definition 4.3 [18] Let
Then the sine operational laws of
• Complement of
• Intersection of
• Union of
• Algebric sum of
• Scalar product of
• Algebric product of
• Power of
Definition 4.4 Let
Then, score and accuracy of
Next, the properties of sine trigonometric operational laws of CNNs are discussed.
Theorem 4.1 Let
•
•
Proof. The proofs are straightforward from the Definition 4.3.
Theorem 4.2 Let
(i).
(ii).
(iii).
(iv).
(v).
Proof. Let
Then, using Definition 4.3 the algebraic sum of two ST-OL-CNNs
(i). For any
Hence the property (i) is proved.
The proof of property (ii). is similar
(iii). For any
Hence the proof of property (iii).
Theorem 4.3 Let
Proof. For any two CNNs
Similarly, for indeterminacy and falsity membership functions.
Hence we get from the Definition 4.2 that
4.2 Subtraction of Two Sine Trigonometric CNNs
Definition 4.5 Let
The subtraction is defined as
Example 4.3 Let two sine trigonometric CNNs be
Then the subtraction is calculated as follows:
4.3 Distance Measure of ST-OL-CNNs
In this section, we discuss different types of distance measures of ST-OL-CNNs.
• Let
• When
• Similarly, when
Example 4.4 Let ST-OLs for two CNNs be given by
Then, the distance measures are
• Manhattan distance measure (Ma-D):
• Euclidean distance measure (ED):
• Minkowski distance measure (MD) when
Note: Here the subtraction of two ST-OL-CNNs is calculated using Eq. (6).
The Minkowski distance measures of ST-OL-CNNs satisfies the following properties:
(i).
(ii).
(iii).
(iv). If
5 Aggregation Operators for ST-OLs-CNSs
In this section, the weighted averaging and geometric aggregation operators are presented for ST-OLs-CNNs with numerical example.
5.1 Sine Trigonometry Weighted Averaging Aggregation Operator (ST-WAAO)
Definition 5.1 Let
Then the ST-WAAOs for CNNs is denoted by
where
Theorem 5.1 Let
Proof. The proof of Theorem 5.1 is examined by mathematical induction on n. For each P,
Step I. For
Using Definition 4.3, the algebraic sum of two ST-OL-CNNs
Step II. Suppose that Eq. (10) holds for
Step III. Next, we have to prove that Eq. (10) holds for
Hence the proof.
Example 5.1 Suppose that
Then absolute value of ST-WAAO-CNN is calculated as follows:
Next, we give some properties of the ST-WAAO-CNNs operator and establish that they preserve idempotency, boundedness, monotonically, and symmetry.
Theorem 5.2 Let
Proof. Let
Hence proved.
Theorem 5.3 Let
Then,
Proof. For any P,
This implies that
similarly,
Also, we have
similarly,
Then,
Theorem 5.4 Let
If
Proof. It follows from Theorem 5.3 and hence the proof is omitted.
Theorem 5.5 Let
Proof. The proof follows from Theorem 5.3.
5.2 Sine Trigonometry Weighted Geometric Aggregation Operator (ST-WGAO)
Definition 5.2 Let
Then the ST-WGAOs for CNNs is denoted by
where
Theorem 5.6 Let
Proof. The proof of theorem 5.6 is examined by mathematical induction on n. For each P,
Step I. For
Using Definition 4.3, the algebraic product of two ST-OL-CNNs
Step II. Suppose that Eq. (12) holds for
Step III. Next, we have to prove the Eq. (12) holds for
Hence the proof.
Example 5.2 Let
Then absolute value of ST-WGAO-CNN is calculated as follows:
Theorem 5.7 Let
Theorem 5.8 Let
Then,
Theorem 5.9 Let
If
Theorem 5.10 Let
The proof of above all theorems 5.7–5.10 follow from Theorems 5.2–5.5 directly.
5.3 Fundamental Properties of ST-AOs for CNNs
Theorem 5.11 Let
Proof. Since
As for any
Thus, by taking
Similarly,
Therefore,
Theorem 5.12 Let
1.
2.
Proof. The proof of the theorem follows from Theorem 5.11.
Theorem 5.13 Let
Here the equality holds if and only if
Proof. The proof of the theorem follows from Theorem 5.11.
This section presents a decision making technique that could be utilized to solve uncertain multi criteria decision making (MCDM) problems with complex neutrosophic information. MCDM problems can be handled by decision matrix, in which all elements are represented in terms of ST-OLs-CNNs with respect to alternatives over criteria/attributes by decision makers. Thus, a decision matrix
Suppose that the complex neutrosophic decision matrix (ST-Ols-CNDM) is denoted by
where all elements are ST-OLs-CNNs
Step 1. The collected vague data are transformed to ST-OLs-CNNs
Step 2. Construct the normalized complex neutrosophic decision matrix
where
If
If
Step 3. The weights of the criteria/attributes are unknown. So the entropy principle 6.1 is used to calculate the weights of criteria/attributes
Step 4. From the normalized decision matrix
Step 5. Calculate the score value of each aggregated value.
Step 6. Rank the alternatives according to their absolute score values.
Shannon proposed the theory of entropy [42], which is a measure of uncertainty in information represented in terms of probability theory. To evaluate relative weights, Shannon's entropy approach interprets the relative intensities of the criterion based on the discrimination among data. The steps in the shannon's entropy approach are as follows:
Step (i). The complex neutrosophic decision matrix
Step (ii). Utilize score function to initial ST-Ols-CN decision matrix
Step (iii). Then, normalize the secondary decision matrix
Step (iv). Calculate the entropy of each criterion
Step (v). Calculate the variation coefficient of criterion
Step (vi). Determine the weight of each criterion
7 Application of the Proposed ST-OLs-Complex Neutrosophic Decision Making Approach
The selection of materials for industry plays an essential role in their functioning. Also, the growing material availability in the world has created a variety of options. But, very less attention has been given to tools and methods that facilitate material selection process. In addition, this process needs to consider multiple properties depending on tools/method requirements to make a better decision. For manufacturers and engineers, it is a crucial and challenging task to select best sustainable option from a number of materials used in the modern industry and many factors are involved in such decision making process. MCDM approaches are more efficient in the selection process of materials. Khandekar et al. [43] utilized decision making approach based on fuzzy axiomatic design principles for material selection. Mayyas et al. [44] implemented fuzzy TOPSIS method to select best eco-material. A fuzzy logic based PROMETHEE method have been used for material selection problems by Gul et al. [45]. Using TOPSIS approach with some popular normalization methods Yang et al. [46] proposed an efficient method for material selection. A systematic review on material selection methods have been explained in detail by Rahim et al. [47].
Case Study. A manufacturing company is planning to buy materials
Step 1. The formation of ST-OLs-complex neutrosophic decision matrix that is Table 2 is derived from usual complex neutrosophic decision matrix (Table 1).
Step 2. All the criteria are benefit type. The normalized ST-OLs of complex neutrosophic decision matrix
Step 3. The weights of the criteria/attributes are unknown. So the entropy principle 6.1 has been used to calculate the following weights of criteria/attributes.
Step 4. From the normalized decision matrix
Step 5. The score values of each alternative are given below:
Step 6. The ranking order of the alternatives according to their amplitude values is listed as follows:
Therefore,
Similarly, Using ST-WGAO-CNN (Eq. (12)) operator, the aggregated complex neutrosophic decision matrix is obtained and is shown in Table 4;
The score value of each alternative are given below:
The ranking order of the alternatives according to their amplitude values is listed as follows:
Then, the ranking order is
7.1 Calculation of Entropy Based Criteria Weights
These are the following steps involved in the Shannon's entropy method to calculate the criteria weights;
Step (i). The initial complex neutrosophic decision matrix
Step (ii). Using score function to initial ST-Ols-CN decision matrix
Step (iii). The normalization of the secondary decision matrix
Step (iv). The entropy of each criterion is given as follows:
Step (v). The variation coefficient of each criterion
Step (vi). Finally, the weight of each criterion
Note: The result satisfies the property that the sum of all complex weights is equal to one. That means
8 Validation of the Proposed Method
The proposed concept of sine trigonometry operational laws of complex neutrosophic decision making approach is verified with entropy based combinative distance-based assessment (CODAS) method. A decision matrix, i.e., Table 2 has been taken for entropy-CODAS method. In the initial process, criteria weights are derived using the steps given in Section 6.1. And the weight values are calculated and given as follows;
Step 1. The ST-OLs-CN decision-making matrix is considered as in Table 2
Step 2. Each element in ST-OLs-CN decision matrix is normalized by the following linear normalization Eq. (14)
Step 3. The ST-OLs-CN weighted normalized decision matrix is calculated by
Step 4. The ST-OLs-CN negative-ideal solution of the weighted normalized decision matrix
Step 5. The Euclidean and Taxicab distances of alternatives from the ST-OLs-CN negative-ideal solution are calculated by Eqs. (15) and (16)
The values are shown in Tables 8 and 9.
Step 6. The relative assessment of ST-OLs-CN matrix is derived from Eq. (17), and shown as in Table 10.
where
Step 7. The assessment value of each alternative is obtained by Eq. (19)
Step 8. Using ST-OLs-CN score function, the score of each
Step 9. Rank the alternatives according to the absolute values
8.1 Discussion and Comparison Analysis
The outcomes of the new and existing techniques are compared in Table 12 to demonstrate the validity of the proposed approach. It is transparent that the optimal alternative is the same for all techniques. As a result, the proposed concept of sine trigonometric operational laws of complex neutrosophic sets performs better in complex decision-making procedures. But, this operator can handle only the particular types of uncertainty which have periodicity in the form of amplitude and phase terms to the three membership functions such as truth, indeterminacy and falsity where amplitude represents the real valued membership functions and an additional term called phase represents periodicity. In this research, the execution of multi-criteria decision making approach their results in complex numbers. So, in order to select the best among them we have to consider the absolute values.
In this study, a decision making method with sine trigonometric operational laws for complex neutrosophic fuzzy sets have been proposed. The operations of ST-OLs-CNNs play a vital role during the decision making process and with help of these operations some of the ST-OLs-CN aggregation operators have been developed in order to make decision over complex vague information. The description of ST-OLs have been given with CNNs in detailed graphical representation and it shows the validity of the ST-OLs. The properties of the proposed sine trigonometric weighted AOs are proved. Further, in the proposed MCDM method, the criteria weights are computed by unsupervised techniques and by combining these methods a new approach called Entropy-ST-OLs-CNDM method has been introduced. Then the functionality of the proposed method is applied to a material selection problem and, feasibility and validity of the approach are investigated in detail with comparative analysis.
In future research, advanced study of the similarity measures of complex neutrosophic sets and complex neutrosophic critic-based approach for handling MCDM problems with unknown weights can be carried out. The recommended approach can also be applied to other fields, such as medical nutrition diagnostics, sustainable supplier selection, and so on.
Funding Statement: This work was supported in part by the Rajamangala University of Technology Suvarnabhumi.
Conflicts of Interest: The authors declare that they have no conflicts of interest to report regarding the present study.
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