Cilt:69 Sayı:02 (2020)

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On equitable coloring of book graph families
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Barani, M.; M., Venkatachalam; Rajalakshmi, K.; Other; Other
A proper vertex coloring of a graph is equitable if the sizes of color classes differ by atmost one. The notion of equitable coloring was introduced by Meyer in 1973. A proper h − colorable graph K is said to be equitably h-colorable if the vertex sets of K can be partioned into h independent color classes V 1 , V 2 , . . . , V h such that the condition ∣ ∣ | V i | − ∣ ∣ V j ∣ ∣ ∣ ∣ ≤ 1 holds for all different pairs of i and j and the least integer h is known as equitable chromatic number of K . In this paper, we find the equitable coloring of book graph, middle, line and central graphs of book graph.
An approach to pre-separation axioms in neutrosophic soft topological spaces
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Açıkgöz, Ahu; Esenbel, Ferhat; Other; Other
In this study, we introduce the concept of neutrosophic soft pre-open (neutrosophic soft pre-closed) sets and pre-separation axioms in neutrosophic soft topological spaces. In particular, the relationship between these separation axioms are investigated. Also, we give a new deﬁnition for neutrosophic soft topological subspace and deﬁne neutrosophic soft pre irresolute soft and neutrosophic pre irresolute open soft functions.
On certain multidimensional nonlinear integrals
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Güller, Özge Özalp; Uysal, Gümrah; Matematik; Fen Fakültesi
The aim of the paper is to obtain generalized convergence results for nonlinear multidimensional integrals of the form: L_{η}(ω;x)=((ηⁿ)/(Ω_{n-1}))∫_{D}K(η|t-x|,ω(t))dt. We will prove pointwise convergence of the family L_{η}(ω;x) as η→∞ at a fixed point x∈D which represents any generalized Lebesgue point of function ω∈L₁(D), where D is an open bounded subset of Rⁿ. Moreover, we will consider the case D=Rⁿ. The aim of the paper is to obtain generalized convergence results for nonlinear multidimensional integrals of the form: L_{η}(ω;x)=((ηⁿ)/(Ω_{n-1}))∫_{D}K(η|t-x|,ω(t))dt. We will prove pointwise convergence of the family L_{η}(ω;x) as η→∞ at a fixed point x∈D which represents any generalized Lebesgue point of function ω∈L₁(D), where D is an open bounded subset of Rⁿ. Moreover, we will consider the case D=Rⁿ.
A solution of a viscosity Cesàro mean algorithm
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) SAHEBİ, Hamid Reza; Other; Other
Based on the viscosity approximation method, we introduce a new cesaro mean approximation method for finding a common solution of split generalized equilibrium problem in real Hilbert spaces. Under certain conditions control on parameters, we prove a strong convergence theorem for the sequences generated by the proposed iterative scheme. Some numerical examples are presented to illustrate the convergence results. Our results can be viewed as a generalization and improvement of various existing results in the current literature.
Best proximity problems for new types of Z -proximal contractions with an application
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Işık, Hüseyin; Aydi, Hassen; Other; Other
In this study, we establish existence and uniqueness theorems of best proximity points for new types of Z -proximal contractions defined on a complete metric space. The presented results improve and generalize some recent results in the literature. Several examples are constructed to demonstrate the generality of our results. As applications of the obtained results, we discuss sufficient conditions to ensure the existence of a unique solution for a variational inequality problem.
On the Chinese Checkers spherical inversions in three dimensional Chinese Checkers space
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Pekzorlu, Adnan; Bayar, Ayşe; Other; Other
In this paper, we study an inversion with respect to a Chinese checkers sphere in the three dimensional Chinese Checkers space, and prove several properties of this inversion. We also study cross ratio, harmonic conjugates and the inverse images of lines, planes and Chinese Checkers spheres in three dimensional Chinese Checkers space.
On the geometry of fixed points of self-mappings on S-metric spaces
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Özgür, Nihal; Taş, Nihal; Other; Other
In this paper, we focus on some geometric properties related to the set Fix(T), the set of all fixed points of a mapping T:X→X, on an S-metric space (X,S). For this purpose, we present the notions of an S-Pata type x₀-mapping and an S-Pata Zamfirescu type x₀-mapping. Using these notions, we propose new solutions to the fixed circle (resp. fixed disc) problem. Also, we give some illustrative examples of our main results. In this paper, we give new solutions to the fixed circle (resp. fixed disc) problem on S-metric spaces. In Section 2, we prove some fixed circle and fixed disc results using different approaches. In Section 3, we give some illustrative examples of our obtained results and deduce some important remarks. In Section 4, we summarize our study and recommend some future works.
A new generalized-upper record values-G family of lifetime distributions
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Kharazmi, Omid; Saadatinik, Ali; Hamedami, G.; Other; Other
A new family of lifetime distributions is introduced via distribution of the upper record values, the well-known concept in survival analysis and reliability engineering. Some important properties of the proposed model including quantile function, hazard function, order statistics are obtained in a general setting. A special case of this new family is proposed by considering the exponential and Weibull distribution as the parent distributions. In addition estimating unknown parameters of specialized distribution is examined from the perspective of the traditional statistics. A simulation study is presented to investigate the bias and mean square error of the maximum likelihood estimators. Moreover, one example of real data set is studied; point and interval estimations of all parameters are obtained by maximum likelihood and bootstrap (parametric and non-parametric) procedures. Finally, the superiority of the proposed model in terms of the parent exponential distribution over other known distributions is shown via the example of real observations.
Robust stability analysis for fuzzy stochastic Hopfield neural networks with time–varying delays
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Gopalakrishnan, N.; Other; Other
This paper investigates the delay-dependent robust stability problem of fuzzy stochastic Hopfield neural networks with random timevarying delays. Moreover, in this paper, the stochastic delay is assumed to satisfy a certain probability distribution. By introducing a stochastic variable with Bernoulli distribution, the neural networks with random time delays is transformed into one with deterministic delays and stochastic parameters. Based on a LyapunovKrasovskii functional and stochastic analysis approach, delay-probability-distribution-dependent stability criteria have been derived in terms of linear matrix inequalities (LMIs), which can be checked easily by the LMI control toolbox. Finally two numerical examples are given to illustrate the effectiveness of the theoretical results.
Almost contact metric and metallic Riemannian structures
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Gherici, Beldjilali; Other; Other
The metallic structure is a fascinating topic that continually generates new ideas. In this work, new metallic manifolds are constructed starting from both almost contact metric manifolds and we obtain some important notions like the metallic deformation. We show that there exists a correspondence between the metallic Riemannian structures and the almost contact metric structures. We give an open question where we propose the first step to study the reverse, i.e. the construction of an almost contact metric structure starting from a metallic Riemannian structure. We give a concrete example to confirm this construction.
A comparative study on the performance of frequentist and Bayesian estimation methods under separation in logistic regression
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Altınışık, Yasin; Other; Other
Separation is one of the most commonly encountered estimation problems in the context of logistic regression, which often occurs with small and medium sample sizes. The method of maximum likelihood (MLE; Fisher) provides spuriously high parameter estimates and their standard errors under separation in logistic regression. Many researchers in social sciences utilize simple but ad-hoc solutions to overcome this issue, such as "doing nothing strategy", removing variable(s) from the model, and combining the levels of the categorical variable in the data causing separation etc. The limitations of these basic solutions have motivated researchers to use more appropriate and innovative estimation techniques to deal with the problem. However, the performance and comparison of these techniques have not been fully investigated yet. The main goal of this paper is to close this research gap by comparing the performance of frequentist and Bayesian estimation methods for coping with separation. A simulation study is performed to investigate the performance of asymptotic, bootstrap-based, and Bayesian estimation techniques with respect to bias, precision, and accuracy measures under separation. In line with the simulation study, a real-data example is used to illustrate how to utilize these methods to solve separation in logistic regression.
On new integral inequalities using mixed conformable fractional integrals
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Çelik, Barış; Set, Erhan; Other; Other
During the past two decades or so, fractional integral operators have been one of the most important tools in the development of inequalities theory. By this means, a lot generalized intergral inequalities involving various the fractional integral operators have been presented in the literature. Very recently, mixed conformable fractional integral operators has been introduced by T. Abdeljawad and with the help of these operators some new integral inequalities are obtained. The main aim of the paper is to establish some new Chebyshev type fractional integral inequalities by using mixed conformable fractional integral operators.
Inverse continuous wavelet transform in weighted variable exponent amalgam spaces
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Kulak, Öznur; Aydın, İsmail; Other; Other
The wavelet transform is an useful mathematical tool. It is a mapping of a time signal to the time-scale joint representation. The wavelet transform is generated from a wavelet function by dilation and translation. This wavelet function satisfies an admissible condition so that the original signal can be reconstructed by the inverse wavelet transform. In this study, we firstly give some basic properties of the weighted variable exponent amalgam spaces. Then we investigate the convergence of the θ-means of f in these spaces under some conditions. Finally, using these results the convergence of the inverse continuous wavelet transform is considered in these spaces.
A note on quasi bi-slant submanifolds of cosymplectic manifolds
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Akyol, Mehmet Akif; Beyendi, Selahattin; Other; Other
The aim of the present paper is to define and study the notion of quasi bi-slant submanifolds of almost contact metric manifolds. We mainly concerned with quasi bi-slant submanifolds of cosymplectic manifolds as a generalization of slant, semi-slant, hemi-slant, bi-slant and quasi hemi-slant submanifolds. First, we give non-trivial examples in order to demostrate the method presented in this paper is effective and investigate the geometry of distributions. Moreover, We study these types of submanifolds with parallel canonical structures.
On Hermite-Hadamard type inequalities for interval-valued multiplicative integrals
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) ZHANG, Zhiyue; ALİ, Muhammad Aamir; BUDAK, Hüseyin; SARIKAYA, Mehmet Zeki; Other; Other
In this work, we define multiplicative integrals for interval-valued functions. We establish some new Hermite-Hadamard type inequalities in the setting of interval-valued multiplicative calculus and give some examples to illustrate our main results. We also discuss special cases of our main results which are the extension of already established results.
Some comments on methodology of cubic rank transmuted distributions
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Yılmaz, Mehmet; HAMELDARBANDI, Monireh; İstatistik; Fen Fakültesi
In this study, at first a new polynomial rank transmutation is proposed. Then, a new cubic rank transmutation is introduced by simplifying the set of transmutation parameters in order to improve its usefulness in statistical modeling. The purpose of this comment is to clarify some issues that exist in the methodology of obtaining the distribution by the cubic transmutation and the stage of proofing it. In this way, both the parameter space is expanded and the process of establishing the cubic transformed distribution family is given.
Lattice structures of automata
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Atani, Shahabaddin Ebrahimi; Sedghi Shanbeh Bazari, Maryam; Other; Other
This paper is motivated by the results in [M. Ito, Algebraic structures of automata, Theoretical Computer Science 428 (2012) 164-168.]. Structures and the number of subautomata of a finite automaton are investigated. It is shown that the set of all subautomata of a finite automaton A is upper semilattice. We give conditions which allow us to determine whether for a finite upper semilattice (L;≤) there exists an automaton A such that the set of all subautomata of A under set inclusion is isomorphic to (L;≤). Examples illustrating the results are presented.
A subclass of pseudo-type meromorphic bi-univalent functions
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Alamoush, Adnan; Other; Other
In this paper, In the present article, a new subclass of pseudo-type meromorphic bi-univalent functions is defined on △={z |:z∈C and 1<|z|<∞}, we derive estimates on the initial coefficient |b₀|, |b₁| and |b₂|. Relevant connections of the new results with various well-known results are indicated. Motivated by the earlier work of (Srivastava, Janani), in the present paper, we introduce a new subclasses of the class Σ′ and the estimates for the coefficients |b₀|,|b₁| and |b₂| are investigated. Some new consequences of the new results are also pointed out.
Recognition of complex polynomial Bezier curves under similarity transformations
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Ören, İdris; İncesu, Muhsin; Other; Other
In this paper, similarity groups in the complex plane C, polynomial curves and complex Bezier curves in C are introduced. Global similarity invariants of polynomial curves and complex Bezier curves in C are given in terms of complex functions. The problem of similarity of two polynomial curves in C are solved. Moreover, in case two polynomial curve (complex Bezier curve) are similar for the similarity group, a general form of all similarity transformations, carrying one curve into the other curve, are obtained.
On some properties of intuitionistic fuzzy soft boundary
(Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Hussain, Sabir; Other; Other
The concept of intuitionistic fuzzy soft sets in a decision making problem and the problem is solved with the help of 'similarity measurement' technique. The purpose of this paper is to initiate the concept of Intuitionistic Fuzzy(IF) soft boundary. We discuss and explore the characterizations and properties of IF soft boundary in general as well as in terms of IF soft interior and IF soft closure. Examples and counter examples are also presented to validate the discussed results.

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