Cilt:68 Sayı:02 (2019)


Recent Submissions

Now showing 1 - 20 of 90
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    I-lacunary statistical convergence of weighted g via modulus functions in 2-normed spaces
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Savaş, Ekrem; Yamancı, Ulaş; Gürdal, Mehmet; Other; Other
    In this paper, we introduce new concepts of I-statistical convergence and I-lacunary statistical convergence using weighted density via modulus functions. Also, we study the relationship between them and obtain some interesting results.
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    Approximation properties of Bernstein-Kantorovich type operators of two variables
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Karahan, Döne; İzgi, Aydın; Other; Other
    In this study, the generalized Bernstein-Kantorovich type operators are introduced and some approximation properties of these operators are studied in the space of continuous functions of two variables on a compact set . The convergence rate of these operators are obtained by means of the modulus of continuity. The Voronovskaya type theorem is given and some differential properties of these operators are proved.
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    [1,2]-Complementary connected domination number of graphs-III
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Mahadevan, G.; Renuka, K.; Other; Other
    A set S⊆V(G) in a graph G is said to be [1,2]-complementary connected dominating set if for every vertex v∈V-S, 1≤|N(v)∩S|≤2 and is connected. The minimum cardinality of [1,2]-complementary connected dominating set is called [1,2]-complementary connected domination number and is denoted by γ_{[1,2]cc}(G). In this paper, we investigate 3-regular graphs on twelve vertices for which γ_{[1,2]cc}(G)=χ(G)=3.
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    On a graph of ideals of a commutative ring
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Khoramdel, Mehdi; Atani, Shahabaddin Ebrahimi; Pishhesari, Saboura Dolati; Other; Other
    In this paper, we introduce and investigate a new graph of a commutative ring R, denoted by G(R), with all nontrivial ideals of R as vertices, and two distinct vertices I and J are adjacent if and only if ann(I∩J)=ann(I)+ann(J). In this article, the basic properties and possible structures of the graph G(R) are studied and investigated as diameter, girth, clique number, cut vertex and domination number. We characterize all rings R for which G(R) is planar, complete and complete r-partite. We show that, if (R,M) is a local Artinian ring, then G(R) is complete if and only if Soc(R) is simple. Also, it is shown that if R is a ring with G(R) is r-regular, then either G(R) is complete or null graph. Moreover, we show that if R is an Artinian ring, then R is a serial ring if and only if G(R/I) is complete for each ideal I of R.
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    On the limit of discrete q-Hermite I polynomials
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Adıgüzel, Rezzan Sevinik; Turan, Mehmet; Alwhishi, Sakina; Other; Other
    Bu çalışmanaın ana konusu ayrık q-Hermite I ve Hermite polinomları arasındaki limit ilişkilerini ele almaktır. Söz konusu limit durumunda ortogonal ilişkileri ve üç terim bağıntıları da sağlanmaktadır. Ayrık q-Hermite I polinomları klasik ortogonal polinomların önemli bir sınıfı olan Hermite polinomlarının q-analoğudur. Bahsi geçen limit durumunda hipergeometrik tipte q-fark denklemi, Rodrigues formülü ve üretici fonksiyonlar da ele alınmıştır.
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    Mean ergodic type theorems
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Oğuz, Gencay; Orhan, Cihan; Other; Other
    Let T be a bounded linear operator on a Banach space X . Replacing the Ces\`{a}ro matrix by a regular matrix A = ( a n j ) Cohen studied a mean ergodic theorem. In the present paper we extend his result by taking a sequence of infinite matrices A = ( A ( i ) ) that contains both convergence and almost convergence. This result also yields an A -ergodic decomposition. When T is power bounded we give a characterization for T to be A -ergodic.
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    Generalizations of some results on generalized polynomial identities
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Eroğlu, Münevver Pınar; Other; Other
    Motivated by the generalized polynomial identities in [1] and [5], our aim is to generalize some of the results in these works. Precisely, we extend the result in [1] on commuting values of the same generalized derivations to the different generalized derivations case by a short proof. Also as an application, we extend a result in [5] on images of a linear map with derivations to generalized derivations case.
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    Decision making for portfolio selection by fuzzy multi criteria linear programming
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Akbaş, Serkan; Dalkılıç, Türkan Erbay; Other; Other
    In daily life events, there are many complexities arising from lack of information and uncertainty. Fuzzy linear programming model has been developed to reduce or eliminate this complexity. Fuzzy linear programming is the process of choosing the optimum solution from among the decision alternatives to achieve a specific purpose in cases where the information is not certain. One of the fields where the lack of information or uncertainty makes it difficult to decide is financial markets. Investors who have a certain amount of accumulations are aiming to increase in various ways as well as protecting the value of their income. While doing this, encounter the problem of deciding to which investment vehicle they need to invest in what extent. Therefore, investors apply to fuzzy linear programming model to eliminate this uncertainty and to create the optimal portfolio. In the portfolio selection process suggestions in the literature, the determination of criteria weights is based on triangular fuzzy numbers. In this study, as an alternative to the Enea and Piazza's portfolio selection model, which uses the triangular fuzzy numbers for criteria weighting, a new model that uses the trapezoidal fuzzy numbers for the same aim was proposed. With the solution of the linear programming model which is based on the determined weights, an alternative solution has been produced to the problem of which investment instrument will be invested at what proportion. The results obtained from the existing methods and the results obtained from the proposed model were compared.
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    Algebraic structure of square matrices over residuated lattices
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Saeid, Arsham Borumand; Eslami, E.; Balaei, S.; Other; Other
    In this paper, we introduce the algebra Mnn(L) of square matrices over residuated lattice L. The operations are induced by the corresponding operations of L. It is shown that the defined algebra behaves like a residuated lattice, but there are some slight differences. The properties of this algebra with respect to special residuated lattices are investigated. The notions of filter and ideal together with their roles are specified.
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    Properties of Δ^{∗}-closed maps in topological spaces
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Meena, K.; Arivuoli, D.; Sivakamasundari, K.; Other; Other
    This paper is concerned with the introduction of a new notion of closed maps namely, Δ^{∗}-closed maps using Δ^{∗}-closed sets and the analysis of their significant properties in topological spaces. Also the nature of Δ^{∗}-closed maps under composition mappings and their applications are explored in this paper.
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    C^{∗}-algebra-valued rectangular b-metric spaces and some fixed point theorems
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Kalpana, G.; Tasneem, Z. Sumaiya; Other; Other
    The concept of C^{∗}-algebra-valued rectangular b-metric spaces is introduced as a generalization of C^{∗}-algebra-valued b-metric spaces. An analogue of Banach contraction principle and Kannan's fixed point theorem is proved in this space. As applications, existence and uniqueness results for a type of operator equation is given.
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    Approximation properties of modified q-Bernstein-Kantorovich operators
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Acu, Ana Maria; Agrawal, Purshottam; Kumar, Dharmendra; Other; Other
    In the present paper we define a q-analogue of the modified Bernstein-Kantorovich operators introduced by Ozarslan and Duman (Numer. Funct. Anal. Optim. 37:92-105,2016). We establish the shape preserving properties of these operators e.g. monotonicity and convexity and study the rate of convergence by means of Lipschitz class and Peetre's K-functional and degree of approximation with the aid of a smoothing process e.g Steklov mean. Further, we introduce the bivariate case of modified q-Bernstein-Kantorovich operators and study the degree of approximation in terms of the partial and total modulus of continuity and Peetre's K-functional. Finally, we introduce the associated GBS (Generalized Boolean Sum) operators and investigate the approximation of the Bogel continuous and Bogel differentiable functions by using the mixed modulus of smoothness and Lipschitz class.
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    (θ,μ,τ)-neighborhood for analytic functions involving modified sigmoid function
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Çağlar, Murat; Orhan, Halit; Other; Other
    In the present investigation we discuss the neighborhoods of analytic functions defined by using modified sigmoid function. Further, we also give some applications of Jack's lemma.
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    On some approximation properties of the Gauss-Weierstrass operators
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Yılmaz, Başar; Other; Other
    In this paper, we present some approximation properties of the Gauss-Weierstrass operators in exponential weighted spaces including norm convergence of them and Voronovskaya and quantitative Voronovskaya-type theorems.
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    An almost orthosymmetric bilinear map
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Yılmaz, Ruşen; Other; Other
    In this paper, as a generalization of the concept of pseudo-almost f-algebra, we define a new concept of almost orthosymmetric bilinear map on a vector lattice and prove that the Arens triadjoint of a positive almost orthosymmetric bilinear map is positive almost orthosymmetric.This also extends results on the order bidual of pseudo-almost f-algebras.
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    (alpha,m1,m2)-convexity and some inequalities of Hermite-Hadamard type
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Kadakal, Huriye; Other; Other
    In this paper, we introduce a new class of extended (alpha;m1;m2)-convex functions. Some algebraic properties of these class functions have been investigated. Some new Hermite-Hadamard type inequalities are derived. Results represent signicant refinement and improvement of the previous results. Also, the author establish a new integral identity and, by this identity, Hölder's and power mean inequality, discover some new Hermite-Hadamard type inequalities for functions whose first derivatives are (alpha;m1;m2)-convex. Our results are new and coincide with the previous results in special cases.
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    Local T2 extended pseudo-quasi-semi metric spaces
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Baran, Tesnim Meryem; Other; Other
    In this paper, we characterize various local T₂ extended pseudo-quasi-semi metric spaces and investigate the relationships among these various forms. Finally, we give some invariance properties of these local T₂ extended pseudo-quasi-semi metric spaces.
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    The M-polynomial of line graph of subdivision graphs
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Mondal, Sourav; De, Nilanjan; Pal, Anita; Other; Other
    Three composite graphs Ladder graph (L_{n}), Tadpole graph (T_{n,k}) and Wheel graph (W_{n}) are graceful graphs, which have different applications in electrical, electronics, wireless communication etc. In this report, we first determine M-polynomial of the Line graph of those three graphs using subdivision idea and then compute some degree based indices of the same.
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    On (λ,A)-statistical convergence of order α
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Şengül, Hacer; Koyun, Özlem; Other; Other
    In the paper [B. de Malafosse and V. Rakočević, Linear Algebra Appl. 420, no. 2-3, (2007), 377--387], authors defined the concept of (λ,A)-statistical convergence. In this paper, the concept of (λ,A)-statistical convergence is generalized to (λ,A)-statistical convergence of order α. Also, we introduce the concept of strong (V,λ,A)-convergence of order α and give some inclusion relations between the concepts of (λ,A)-statistical convergence of order α and strong (V,λ,A)-convergence of order α.
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    Position vectors of curves with recpect to Darboux frame in the Galilean space G³
    (Ankara Üniversitesi Fen Fakültesi, 2019-08-01) Şahin, Tevfik; Dirişen, Buket Ceylan; Other; Other
    In this paper, we investigate the position vector of a curve on the surface in the Galilean 3-space G³. Firstly, the position vector of a curve with respect to the Darboux frame is determined. Secondly, we obtain the standard representation of the position vector of the curve with respect to Darboux frame in terms of the geodesic, normal curvature and geodesic torsion. As a result of this, we define the position vectors of geodesic, asymptotic and normal line along with some special curves with respect to Darboux frame. Finally, we elaborate on some examples and provide their graphs.