#### Abstract

The purpose of this paper is to present a new method to solve the decision-making algorithm based on the cosine similarity and distance measures by utilizing the uncertain and vague information. A complex interval-valued q-rung orthopair fuzzy set (CIVQROFS) is a reliable and competent technique for handling the uncertain information with the help of the complex-valued membership grades. To address the degree of discrimination between the pairs of the sets, cosine similarity measures (CSMs) and distance measures (DMs) are an accomplished technique. Driven by these, in this manuscript, we defined some CSMs and DMs for the pairs of CIVQROFSs and investigated their several properties. Choosing that the CSMs do not justify the axiom of the similarity measure (SM), then we investigate a technique to developing other CIVQROFSs-based SMs using the explored CSMs and Euclidean DMs, and it fulfills the axiom of the SMs. In addition, we find the cosine DMs (CDMs) by considering the inter-relationship between the SM and DMs; then, we have modified the procedure for the rank of partiality by similarity to the ideal solution method for the CDMs under investigation, which can deal with the associated decision-making problems not only individually from the argument of the opinion of geometry but also the fact of the opinion of algebra. Finally, we provide a numerical example to demonstrate the practicality and effectiveness of the proposed procedure, which is also in line with existing procedures. Graphical representations of the measures developed are also used in this manuscript.

#### 1. Introduction

Decision-making is one of the most difficult processes in our day-to-day life in which we make decisions at all times. Uncertainty, however, is an unavoidable phenomenon, as a result of which the rating for assessing a given object is not clearly appraisable. There is therefore an excessive need for theory to extract the information more precisely. For example, when the institute decides whether to enroll the tutoring team, the ten-member committee of the authorities has assessed the persons selected, seven of whom have agreed to employ the person, two of whom have expressed disapproval of the job, and the additional one has not given a clear judgment. It is therefore difficult, in such circumstances, to take a decision into account. To characterize the excess of knowledge, Atanassov’s intuitionistic fuzzy set (IFS) [1] was investigated by including the term falsity in the fuzzy set (FS) environment [2] in order to deal with unreliable and problematic information in decision-making issues. The term “Truth” and the term “Falsity” in IFS contains the rule that the sum of the two terms is restarted to [0, 1]. The IFS deals with the crisp numbers and fails to deal with the number of the intervals. To address this, Atanassov [3] has developed a theory of interval-assessed IFS containing the degree of truth and falsehood in the form of a subinterval of unit interval. The idea of IFS has received a great deal of attention from separate scholars and has been widely used by many scholars in a diverse environment (for more details, we refer to [4–7] and their references). Due to some complications, the IFS is unable to manage some of the daily life issues, for example, if a person gives 0.6 for true grade and 0.5 for falsehood, then the sum of the two values is extended from [0, 1], and the IFS is unable to explain these types of information precisely. The theory of Pythagorean FS (PFS) has therefore been investigated by Yager [8], which is a competent and capable technique to handle unreliable and problematic information in decision-making problems. The term “Truth” and the term “Falsity” in PFS contains the rule that the sum of the squares of both terms is restarted to [0, 1]. He theory of interval-valued PFS was developed by Garg [9], which contains the degree of truth and falsehood in the form of a subinterval of the unit interval. Since its existence, many scholars have addressed the problems of the decision-making proves using PFS features [10–14]. However, sometimes, the PFS is unable to manage ratings of the expert during the evaluation process. For example, if a person gives 0.9 for true grade and 0.8 for falsehood, then the sum of the squares of both values is extended from [0, 1], and the PFS is unable to explain these types of information precisely. The q-rung orthopair FS (QROFS) theory has therefore been investigated by Yager [15] as a competent and capable technique for dealing with decision-making issues. In QROFS, the term “Truth” and the term “Falsity” contain the rule that the sum of the q-powers of both terms is restarted to [0, 1]. The theory of interval-valued QROFS was developed by Joshi et al. [16], which includes the degree of truth and falsehood in the form of a subinterval of the unit interval. The idea of QROFS has received a great deal of attention from separate scholars and has been widely used by many scholars in the environment of different fields [17–19].

All of the abovementioned algorithms have been widely used by researchers in the decision-making process, but these approaches are limited in access to manage their variations during the given period of time. For example, data from the “Medical Investigation, Biometric, and Facial Recognition Database” continuously transform at the same time as the period passes. Thus, in order to deal with these types of problems, the range of truth and falsehood degrees is changed from the actual subset to the unit disk of the complex plane by Alkouri and Salleh [20], and thus, the notion of the complex IFS (CIFS) has been established by extending the complex FS (CFS) [21] to decision-making issues. The term “Truth” and the term “Falsity” in the CIFS contain the rule that the sum of the real parts (also for imaginary parts) of both terms lies at [0, 1]. The theory of complex interval-valued IFS was developed by Garg and Rani [22] which contains the degree of truth and falsity in the form of a subinterval of the unit interval. The idea of the CIFS has received a great deal of attention from the scholars [23–26] and has been widely used in the different areas. The CIFS is limited in access due to their restriction on the sum of the degrees to be 1, for instance, if a person gives for truth grade and for falsity, then clearly 0.6 + 0.5 > 1 and hence does not satisfy the properties of CIFS. Thus, such types of the ratings are not accessed under the CIFS environment. The theory of complex PFS (CPFS) has therefore been investigated by Ullah et al. [27] which is a competent and capable technique for dealing with unreliable and problematic information on decision-making issues. The term of truth and the term of falsity contains in CPFS with a rule, that is, the sum of the squares of the real parts (also for imaginary parts) of both terms is restarted to [0, 1]. The idea of CPFS has received extensive attention from separated scholars, and numerous scholars have widely utilized it in the environment of different areas [28]. Due to some complications, the CPFS is not able to manage some daily life issues, for instance, if a person gives for truth grade and for falsity, then the sum of the squares of the real parts (also for imaginary parts) of both values is extended from [0, 1], and the CPFS is not able to explain such types of information accurately. Therefore, the theory of complex QROFS (CQROFS) was investigated by Liu et al. [29, 30] which is a proficient and capable technique to handle unreliable and problematic information in decision-making issues. The term of truth and the term of falsity contain in CQROFS with a rule, that is, the sum of the q-powers of the squares of the real parts (also for imaginary parts) of both terms is restarted to [0, 1]. The theory of complex interval-valued QROFS was developed by Garg et al. [31] which contains the grade of truth and falsity in the form of the subinterval of unit interval. The idea of CQROFS has received extensive attention from separated scholars, and numerous scholars have widely utilized it in the environment of different areas [32–37].

In the event of a conflict, the SM is a competent tool for examining the interrelationships between any number of CQROFSs and a number of scholars who have used it in separate areas [35]. Garg and Rani [38] also explored information measures based on the IFCS. Garg and Rani [39] have developed the theory of a robust correlation coefficient based on the CYPS. However, to date, SMs among CQROFSs have not been investigated. Keeping in mind the advantages of SMs, the CQROFSs theory is a reliable technique for managing awkward and unreliable information on daily issues. The main investigation of this manuscript is summarized as follows:(1)The CSMs and Euclidean DMs (EDMs) by using CQROFSs and their properties are investigated(2)Choosing that the CSMs do not justify the axiom of similarity measure (SM), we investigate a technique to develop other SMs based on CQROFSs using the explored CSMs and EDMs, and it fulfills the axiom of the SMs(3)To find a cosine DMs (CDMs) based on CQROFSs, by considering the inter-relationship among the SM and DMs, we modified the procedure for the rank of partiality by similarity to the ideal solution method to the investigated CDMs, which can be arranged with the associated decision-making troubles not only individually from the argument of the opinion of geometry but also the fact of the opinion of algebra(4)A sensible example to demonstrate the practicality and efficiency of the suggested procedure is provided, which is also matched with additional existing procedures(5)The graphical representations of the developed measures are also utilized in this manuscript

The purpose of this manuscript is summarized as follows. In Section 2, we briefly recall the concept of CIFSs, CPFSs, and CQROFSs and their fundamental laws. In Section 3, we developed the idea of CSMs and DMs by using CQROFNs. In Section 4, we utilized the TOPSIS method in the environment of the MADM procedure to find the reliability and effectiveness of the investigated measures. In Section 5, we discussed the comparative analysis of the proposed work with some existing approaches. The conclusion of this manuscript is discussed in Section 6.

#### 2. Preliminaries

In this investigation work, we recall the main ideas of CIVIFSs, CIVPFSs, and CIVQROFSs and their fundamental laws. In this study, we use the symbol for universal sets and the truth and falsity and degrees are shown by and , where and .

*Definition 1. *(see [22]). A CIVIFS is stated bywhererepresent the degrees of agreement and disagreement with the conditions that and . Moreover, the termsis the degree of indeterminacy.

*Definition 2. *A CIVPFS is demonstrated bywhererepresent the degrees of agreement and disagreement with the conditions that and . Moreover, the termis expressed as the degree of indeterminacy.

*Definition 3. *(see [31]). A CIVQROFS is described bywhererepresent the degrees of agreement and disagreement with the conditions that and . Moreover, the termis expressed as the degree of indeterminacy.

Throughout, this manuscript, the complex interval-valued q-rung orthopair fuzzy numbers (CIVQROFNs) are represented by . Additionally, by using this CIVQROFN, we define the score and accuracy values such thatTo find the relationships between any number two CIVQROFNs,we use the following rules:(1)If .(2)If .(3)If .(a)If .(b)If .

#### 3. Cosine Similarity Measures and Distance Measures between CIVQROFSs

In this section, we investigate some CSMs (“cosine similarity measures”) and DMs (“distance measures”) between the pairs of the CIVQROFNs. Some cases of the presented works are also discussed.

*Definition 4. *For any two CIVQROFNs,are based on a universal set ; then, the CSM, denoted by , is defined by

Theorem 1. *For any two CIVQROFNs,are based on a universal set ; then, the CSM holds the following conditions: *(1)*(2)**(3)** if , that is, and *

*Proof. *Based on Definition (10), conditions (1) and (4) are straightforward. Moreover, if we choose the , that is,thenHence, we obtain .

By using the weight vector with a rule, that is, , then the WCSM (“weighted cosine similarity measure”) is defined as follows.

*Definition 5. *For any two CIVQROFNs,are based on a universal set ; then, the is demonstrated byFor any two CIVQROFNs,are based on a universal set ; if we choose the value of weight vector , then the is reduced to .

Theorem 2. *For any two CIVQROFNs,are based on a universal set ; then, the holds the following conditions:*(1)*(2)**(3)** if , that is, and *

*Proof. *Straightforward.

Lemma 1. *For any two fuzzy sets and , if a measure holds the following axioms,*(1)*(2)**(3)**then, we say that is called the similarity measure. On the contrary, a distance measure is a complement to the similarity measure stated as . Moreover, we develop the idea of EDM (“Euclidean distance measure”), which is demonstrated below.*

*Definition 6. *For any two CIVQROFNs,are based on a universal set ; then, the