Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    A New Numerical Algorithm Based on Quintic B-Spline and Adaptive Time Integrator for Cou- Pled Burger's Equation
    (Tabriz University, 2023) Çiçek, Yeşim; Gücüyenen Kaymak, Nurcan; Bahar, Ersin; Gürarslan, Gürhan; Tanoğlu, Gamze
    In this article, the coupled Burger's equation which is one of the known systems of the nonlinear parabolic partial differential equations is studied. The method presented here is based on a combination of the quintic B-spline and a high order time integration scheme known as adaptive Runge-Kutta method. First of all, the application of the new algorithm on the coupled Burger's equation is presented. Then, the convergence of the algorithm is studied in a theorem. Finally, to test the efficiency of the new method, coupled Burger's equations in literature are studied. We observed that the presented method has better accuracy and efficiency compared to the other methods in the literature. © 2023 University of Tabriz. All Rights Reserved.
  • Article
    An Operator Splitting Approximation Combined With the Supg Method for Transport Equations With Nonlinear Reaction Term
    (Tech Science Press, 2012) Baysal, Onur; Tanoğlu, Gamze
    In this work, an operator splitting method is proposed in order to obtain a stable numerical solution for transport equation with non-linear reaction term. We split the transport equation into a reaction part and an advection diffusion part. The former one which becomes a nonlinear ordinary differential equation can be approximated by the simple higher order integrator or solved exactly. The later one is approximated by the Streamline-Upwind Petrov-Galerkin (SUPG) method combined with the generalized Euler time integration (q-method). Numerical results that illustrate the good performance of this method are reported.
  • Article
    Citation - Scopus: 2
    A Conserved Linearization Approach for Solving Nonlinear Oscillation Problems
    (Natural Sciences Publishing, 2018) Korkut, Sıla Övgü; Gücüyenen Kaymak, Nurcan; Tanoğlu, Gamze
    Nonlinear oscillation problems are extensively used in engineering and applied sciences. Due to non-availability of the analytic solutions, numerical approaches have been used for these equations. In this study, a numerical method which is based on Newton-Raphson linearization and Fréchet derivative is suggested. The convergence analysis is also studied locally. The present method is tested on three examples: damped oscillator, Van-der Pol equation and Schrödinger equation. It is shown that the obtained solutions via the present method are more accurate than those of the well-known second order Runge-Kutta method. When examining the present method, preservation of characteristic properties of these equations is also considered. The obtained results show that the present method is applicable with respect to the efficiency and the physical compatibility.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    A1-L10 Phase Boundaries and Anisotropy Via Multiple-Order Theory for an Fcc Alloy
    (European Mathematical Society Publishing House, 2003) Tanoğlu, Gamze; Braun, Richard J.; Cahn, John W.; McFadden, Geoffrey B.
    The dependence of thermodynamic properties of planar interphase boundaries (IPBs) and antiphase boundaries (APBs) in a binary alloy on an fcc lattice is studied as a function of their orientation. Using a recently developed diffuse interface model based on three non-conserved order parameters and the concentration, and a free energy density that gives a realistic phase diagram with one disordered phase (A1) and two ordered phases (L12 and L10) such as occur in the Cu-Au system, we are able to find IPBs and APBs between any pair of phases and domains, and for all orientations. The model includes bulk and gradient terms in a free energy functional, and assumes that there is no mismatch in the lattice parameters for the disordered and ordered phases.We catalog the appropriate boundary conditions for all IPBs and APBs. We then focus on the IPB between the disordered A1 phase and the L10 ordered phase. For this IPB we compute the numerical solution of the boundary value problem to find its interfacial energy, γ as a function of orientation, temperature, and chemical potential (or composition). We determine the equilibrium shape for a precipitate of one phase within the other using the Cahn-Hoffman "-vector" formalism. We find that the profile of the interface is determined only by one conserved and one non-conserved order parameter, which leads to a surface energy which, as a function of orientation, is "transversely isotropic" with respect to the tetragonal axis of the L10 phase. We verify the model's consistency with the Gibbs adsorption equation.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Convergence Analysis and Numerical Solution of the Benjamin-Bona Equation by Lie-Trotter Splitting
    (TUBITAK, 2018) Zürnacı, Fatma; Gücüyenen Kaymak, Nurcan; Seydaoğlu, Muaz; Tanoğlu, Gamze
    In this paper, an operator splitting method is used to analyze nonlinear Benjamin-Bona-Mahony-type equations. We split the equation into an unbounded linear part and a bounded nonlinear part and then Lie-Trotter splitting is applied to the equation. The local error bounds are obtained by using the approach based on the differential theory of operators in a Banach space and the quadrature error estimates via Lie commutator bounds. The global error estimate is obtained via Lady Windermere's fan argument. Finally, to confirm the expected convergence order, numerical examples are studied.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 4
    An Efficient Iterative Algorithm for Solving Non-Linear Oscillation Problems
    (Faculty of Sciences and Mathematics, University of Nis, 2017) Korkut Uysal, Sıla Övgü; Tanoğlu, Gamze
    A new iterative method is presented for numerical solution of nonlinear evolutionary problems. The convergence properties of the proposed method are analysed in abstract framework by using the concepts of consistency, stability and order. Both the ϕ-functions and semigroup properties are used to overcome the presence of unboundedness of the operator. In order to confirm the theoretical results, the method is applied to three benchmark problems from the literature. The numerical results are compared with traditional splitting methods and confirm that the proposed method is more accurate as well as more efficient than the traditional splitting methods.
  • Article
    Citation - WoS: 16
    Citation - Scopus: 16
    Strang Splitting Method for Burgers-Huxley Equation
    (Elsevier Ltd., 2016) Çiçek, Yeşim; Tanoğlu, Gamze
    We derive an analytical approach to the Strang splitting method for the Burgers-Huxley equation (BHE) ut+αuux-ε uXX=β(1-u)(u-γ)u. We proved that Srtang splitting method has a second order convergence in Hs(R), where Hs(R) is the Sobolev space and s is an arbitrary nonnegative integer. We numerically solve the BHE by Strang splitting method and compare the results with the reference solution.
  • Article
    Cmmse-Convergence Analysis for Operator Splitting Methods With Application To Burgers-Huxley Equation
    (Natural Sciences Publishing, 2015) Çiçek, Yeşim; Tanoğlu, Gamze
    We provide an error analysis of the operator splitting method of the Lie-Trotter type applied to the Burgers-Huxley equation ut + αuux - εuxx = β(1 - u)(u - γ)u. We show that the Lie-Trotter splitting method converges with the expected rate in Hs(R), where Hs(R) is the Sobolev space and s is an arbitrary nonnegative integer. We split the equation into linear and nonlinear parts and apply numerical methods for these subproblems. We present errors and confirm the theoretical results with the numerical example.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    The Convergence of a New Symmetric Iterative Splitting Method for Non-Autonomous Systems
    (Taylor and Francis Ltd., 2012) Tanoğlu, Gamze; Korkut, Sıla
    The iterative splitting methods have been extensively applied to solve complicated systems of differential equations. In this process, we split the complex problem into several sub-problems, each of which can be solved sequentially. In this paper, we construct a new symmetric iterative splitting scheme based on the Magnus expansion for solving non-autonomous problems. We also study its convergence properties by using the concepts of stability, consistency, and order. Several numerical examples are illustrated to confirm the theoretical results by comparing frequently used methods. © 2012 Copyright Taylor and Francis Group, LLC.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 14
    Higher Order Operator Splitting Methods Via Zassenhaus Product Formula: Theory and Applications
    (Elsevier Ltd., 2011) Geiser, Jürgen; Tanoğlu, Gamze; Gücüyenen, Nuran
    In this paper, we contribute higher order operator splitting methods improved by Zassenhaus product. We apply the contribution to classical and iterative splitting methods. The underlying analysis to obtain higher order operator splitting methods is presented. While applying the methods to partial differential equations, the benefits of balancing time and spatial scales are discussed to accelerate the methods. The verification of the improved splitting methods are done with numerical examples. An individual handling of each operator with adapted standard higher order time-integrators is discussed. Finally, we conclude the higher order operator splitting methods.