# Cilt:69 Sayı:01 (2020)

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Item ERRATUM TO: "NEIGHBORHOOD FOR ANALYTIC FUNCTIONS INVOLVING MODIFIED SIGMOID FUNCTION" [COMMUN. FAC. SCI. UNIV. ANK. SER. A1 MATH. STAT., 68(2) (2019), 2161-2169(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Orhan, Halit; Çağlar, Murat; Other; OtherShow more We draw attention to some corrections in the section of "Applications of Jack's Lemma" which appear in the above-mentioned paper (see 3). Our results have changed due to the lack of the (1/(τ(s))) factor on the left side of equation (in page 2166, line 24). So, we correct them in the following:Show more Item On the stability analysis of the time-fractional variable order Klein-Gordon equation and a numerical simulation(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Deniz, Sinan; Other; OtherShow more In this paper, the Klein - Gordon equation is generalized using the concept of the variational order derivative. We try to construct the Crank-Nicholson scheme for numerical solutions of the modified Klein- Gordon equation. Stability analysis of the Crank-Nicholson scheme is examined and analyzed to prove the proposed method is stable for solving the time-fractional variable order Klein- Gordon equation. A numerical example is also given for illustration.Show more Item Approximation by sampling type discrete operators(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Aslan, İsmail; Other; OtherShow more In this paper, we deal with discrete operators of sampling type. It is known that this type of operators are related to generalized sampling series and they have important applications. In this work, using bounded and uniformly continuous functions we get general estimations under usual supremum norm with the help of summability method. We also study the degree of approximation with respect to suitable Lipschitz class of continuous functions. Finally, we give specific kernels which verify our kernel assumptions.Show more Item Some general integral inequalities for Lipschitzian functions via conformable fractional integral(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Turhan, Sercan; İşcan, İmdat; Numan, Selim; Other; OtherShow more In this paper, the author establishes some Hadamard-type and Bullen-type inequalities for Lipschitzian functions via Riemann Liouville fractional integral.Show more Item Generalized difference sequence spaces of fractional order defined by Orlicz functions(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Aral, Nazlım Deniz; Et, Mikail; Other; OtherShow more The main purpose of this paper is to introduce the concepts of Δ^{α}-lacunary statistical convergence of order β (0<β≤1) with the fractional order of α and Δ^{α}-lacunary strongly convergence of order β (0<β≤1) with the fractional order of α. We establish some connections between Δ^{α}-lacunary strongly convergence of order β and Δ^{α}-lacunary statistical convergence of order β.Show more Item First order maximally dissipative singular differential operators(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Ismailov, Zameddin; Al, Pembe İpek; Other; OtherShow more In this paper, using the Calkin-Gorbachuk method, the general form of all maximal dissipative extensions of the minimal operator generated by first order linear multipoint symmetric singular differential-operator expression in the direct sum of Hilbert space of vector-functions has been found. Later on, the structure of spectrum of these extensions is researched. Finally, the results are supported by an application.Show more Item Forecasting mortality rates with a general stochastic mortality trend model(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Etkin, Hasgül; Selçuk-Kestel, A. Sevtap; Okur, Yeliz Yolcu; Other; OtherShow more This paper presents a model, which can closely estimate the future mortality rates whose efficiency is performed through the comparisons with respect to Lee-Carter and mortality trend models. This general model estimates the logit function of death rate in terms of general tendency of the mortality evolution independent of age, the mortality steepness, additional effects of childhood, youth and old age. Generalized linear model (GLM) is used to estimate the parameters. Moreover, the weighted least square (WLS) and random walk with drift (RWWD) methods are employed to project the future values of the parameters. In order to ensure the stability of the outputs and construct the confidence intervals, Monte Carlo simulation is used. The impact of the proposed model is implemented on USA, France, Italy, Japan and Israel mortality rates for both genders based on their ageing structure. A detailed comparison study is performed to illustrate modified mortality rates on the net single premiums over mortality trend model and Lee-Carter model.Show more Item Alternative partner curves in the Euclidean 3-space(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Yılmaz, Beyhan; Has, Aykut; Other; OtherShow more In the present paper, a new type of special curve couple which are called WC^{∗}-partner curves are introduced according to alternative moving frame {N,C,W}. The distance function between the corresponding points of reference curve and its partner curve is obtained. Besides, the angle function between the vector fields of alternative frame of the curves is expressed by means of alternative curvatures f and g. In addition to these, various characterizations are obtained related to these curves.Show more Item On the intuitionistic fuzzy projective Menelaus and Ceva's conditions(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Akça, Ziya; Bayar, Ayşe; Ekmekçi, Süheyla; Other; OtherShow more In this work, the intuitionistic fuzzy versions of Menelaus and Ceva's theorems in intuitionistic fuzzy projective plane are defined and the conditions to the intuitionistic fuzzy versions of Menelaus and Ceva 6-figures are determined.Show more Item A note on hyperbolic (p,q)-Fibonacci quaternions(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Yağmur, Tülay; Other; OtherShow more In this paper, we introduce a new quaternion sequence called hyperbolic (p,q)-Fibonacci quaternions. This new quaternion sequence includes hyperbolic Fibonacci, hyperbolic k-Fibonacci, hyperbolic Pell, hyperbolic k-Pell, hyperbolic Jacobsthal, hyperbolic k-Jacobsthal quaternions. We give generating function and Binet formula for these quaternions. We also obtain some identities such as d'Ocagne's, Catalan's and Cassini's identities involving hyperbolic (p,q)-Fibonacci quaternions.Show more Item Generalized Hermite-Hadamard type inequalities for products of co-ordinated convex functions(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Budak, Hüseyin; Tunç, Tuba; Other; OtherShow more In this paper, we think products of two co-ordinated convex functions for the Hermite-Hadamard type inequalities. Using these functions we obtained Hermite-Hadamard type inequalities which are generalizations of some results given in earlier works.Show more Item Wijsman asymptotical I_2-statistically equivalent double set sequences of order η(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Ulusu, Uğur; Gülle, Esra; Other; OtherShow more In this study, we present notions of Wijsman asymptotical I₂-statistically equivalence of order η, Wijsman asymptotical I₂-Cesàro equivalence of order η and Wijsman asymptotical strongly p-I₂-Cesàro equivalence of order η for double set sequences where 0<η≤1. Also, we investigate some properties of these notions and some relationships between them.Show more Item Fourier-Bessel transforms of Dini-Lipschitz functions on Lebesgue spaces L p , γ ( R n + )(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Ekincioğlu, İsmail; Kaya, Esra; Ekincioğlu, Şeyma; Other; OtherShow more In this paper, we prove a generalization of Titchmarsh's theorem for the Laplace-Bessel differential operator in the space L p , γ ( R n + ) for functions satisfying the ( ψ , p ) -Laplace-Bessel Lipschitz condition for $1Show more Item Relative subcopure-injective modules(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Alagöz, Yusuf; Other; OtherShow more In this paper, copure-injective modules is examined from an alternative perspective. For two modules A and B, A is called B-subcopure-injective if for every copure monomorphism f : B → C and homomorphism g : B → A, there exists a homomorphism h : C → A such that hf=g. For a module A, the subcopure-injectivity domain of A is defined to be the collection of all modules B such that A is B-subcopure-injective. Basic properties of the notion of subcopure-injectivity are investigated. We obtain characterizations for various types of rings and modules, including copure-injective modules, right CDS rings and right V-rings in terms of subcopure-injectivity domains. Since subcopure-injectivity domains clearly contains all copure-injective modules, studying the notion of modules which are subcopure-injective only with respect to the class of copure-injective modules is reasonable. We refer to these modules as sc-indigent. We studied the properties of subcopure-injectivity domains and of sc-indigent modules and investigated over some certain rings.Show more Item Interval oscillation criteria for impulsive conformable fractional differential equations(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Raja, Thangaraj; Bolat, Yaşar; Logaraasi, Kandhasamy; Sadhasivam, Vadivel; Other; OtherShow more In this paper, we derive new interval oscillation criteria for impulsive conformable fractional differential equations having fixed moments of impulse actions. The results are extended to a more general class of nonlinear impulsive conformable fractional differential equations. Examples are also given to illustrate the relevance of the result.Show more Item A comparison of different methods of estimation for the flexible Weibull distribution(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Ali, Sajid; Dey, Sanku; Tahir, M. H.; Mansoor, Muhammad; Other; OtherShow more This article presents different parameter estimation methods for flexible Weibull distribution introduced by Bebbington et al. (Reliability Engineering and System Safety 92:719-726, 2007), which is a modified version of the Weibull distribution and is suitable to model different shapes of the hazard rate. We consider both frequentist and Bayesian estimation methods and present a comprehensive comparison of them. For frequentist estimation, we consider the maximum likelihood estimators, least squares estimators, weighted least squares estimators, percentile estimators, the maximum product spacing estimators, the minimum spacing absolute distance estimators, the minimum spacing absolute log-distance estimators, Cramér von Mises estimators, Anderson Darling estimators, and right tailed Anderson Darling estimators, and compare them using a comprehensive simulation study. We also consider Bayesian estimation by assuming gamma priors for both shape and scale parameters. We use a Markov Chain Monte Carlo algorithm to compute the posterior summaries. A real data example is also a part of this work.Show more Item Generalized fuzzy subhyperspaces based on fuzzy points(Ankara Üniversitesi Fen Fakültesi, 2019-06-30) Dehghan, Omid Reza; Norouzi, M.; Other; OtherShow more We define (∈,∈∨q^{δ})-fuzzy subhyperspaces and (∈,∈∨q_{k}^{δ})-fuzzy subhyperspaces, as a generalization of fuzzy subhyperspaces, (∈,∈∨q)-fuzzy subhyperspaces and (∈,∈∨q_{k})-fuzzy subhyperspaces. In this way, we show that (∈,∈∨q_{k}^{δ})-fuzzy subhyperspaces are the largest family of generalized fuzzy subhyperspaces based on concepts of belongingness and quasi-coincidence. Moreover, we study some properties and investigate the difference of generalized fuzzy subhyperspaces, supported by examples.Show more Item Grand Lorentz sequence space and its multiplication operator(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Oğur, Oğuz; Other; OtherShow more In this paper, we introduce the grand Lorentz sequence spaces ℓ_{p,q)}^{θ} and study on some topological properties. Also, we characterize some properties of the multiplication operator, such as compactness, Fredholmness etc., defined on ℓ_{p,q)}^{θ}.Show more Item A comparative study of classifiers for early diagnosis of gestational Diabetes Mellitus(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Muller, Priya Shirley; Nirmala, M.; Other; OtherShow more Gestational Diabetes Mellitus (GDM), usually found deploying a medical test called the Oral Glucose Tolerance Test (OGTT), is a prevalent complication during pregnancy. Early detection of GDM and identifying the most influential risk factors of GDM pose to be a challenging problem and is found to be crucial as GDM has dreadful health indications for both mother and the baby. The performances of computational techniques like Radial Basis Function (RBF) neural network and Multilayer Perceptron Network (MLP) were collated with that of the statistical technique Discriminant Analysis (DA) on real time GDM datasets for diagnosis of GDM in multigravida pregnant women, specifically women who have been pregnant more than once, without even a visit to the hospital. The most influential risk factors were identified using DA while the overall performance of MLP beyond doubt established itself to be the most effective technique for early diagnosis of GDM in women during pregnancy.Show more Item The Gompertz extended generalized exponential distribution: properties and applications(Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Eghwerido, J.T.; Adubısı, Obinna Damian; Nzeı, Lawrence; Davıd, Ikwuoche John; Other; OtherShow more In this article, a new class of distribution in the exponential family of distributions called the Gompertz extended generalized exponential distribution (G-EGE) for life time processes is proposed. The mathematical properties of the G-EGE distribution such as the reliability, hazard rate function, reversed hazard, cumulative. odd functions, quantiles function, kurtosis, skewness and order statistics were derived. The parameter estimates of the G-EGE distribution were estimated using the maximum likelihood estimation method. The efficiency and flexibility of the G-EGE distribution were examined using a simulation study and a real life data application. The results revealed that the G-EGE distribution outperformed some of the existing distributions considered in this study.Show more