Idris Dag

Ozlem Ersoy Hepson, Alper Korkmaz, Idris Dag

The extended definition of the polynomial B-splines may give a chance to improve the results obtained by the classical cubic polynomial B-splines. Determination of the optimum value of the extension parameter can be achieved by scanning some intervals containing zero. This study aims to solve some initial boundary value problems con- structed for the Gardner equation by the extended cubic B-spline collocation method.The test problems are derived from some analytical studies to validate the efficiency and accuracy of the suggested method. The conservation laws are also determined to observe them remain constant as expected in theoretical aspect. The stability of the proposed method is investigated by the Von Neumann analysis.

Ozlem Ersoy, Idris Dag

In this study, we set up a numerical technique to get approximate solutions of Fisher's equation which is one of the most important model equation in population biology. We integrate the equation fully by using combination of the trigonometric cubic B-spline functions for space variable and Crank-Nicolson for the time integration. Numerical results have been presented to show the accuracy of the current algorithm. We have seen that the proposed technique is a good alternative to some existing techniques for getting solutions of the Fisher's equation.

Ozlem Ersoy, Idris Dag, Ali Sahin

In this paper, we investigate the numerical solutions of the cubic nonlinear Schrodinger equation via the exponential B-spline collocation method. Crank-Nicolson formulas are used for time discretization of the target equation. A linearization technique is also employed for the numerical purpose. Four numerical examples related to single soliton, collision of two solitons that move in opposite directions, the birht of standing and mobile solitons and bound state solution are considered as the test problems. The accuracy and the efficiency of the purposed method are measured by max error norm and conserved constants. The obtained results are compared with the possible analytical values and those in some earlier studies.

Ozlem Ersoy Hepson, Alper Korkmaz, Idris Dag

The extended form of the classical polynomial cubic B-spline function is used to set up a collocation method for some initial boundary value problems derived for the Korteweg-de Vries-Burgers equation. Having nonexistence of third order derivatives of the cubic B-splines forces us to reduce the order of the term uxxx to give a coupled system of equations. The space discretization of this system is accomplished by the collocation method following the time discretization with Crank-Nicolson method. Two initial boundary value problems, one having analytical solution and the other is set up with a non analytical initial condition, have been simulated by the proposed method.

Ozlem Ersoy Hepson, Idris Dag

In this paper, numerical solutions of singularly perturbed boundary value problems are given by using variants of finite element method. Both Galerkin and subdomain Galerkin method based on quadratic B-spline functions are applied over the geometrically graded. Results of some text problems are compated with analytical solutions of the singularly perturbed problem

Melis Zorsahin Gorgulu, Idris Dag

In this paper, the exponential B-spline functions are used for the numerical solution of the advection-diffusion equation. Two numerical examples\ related to pure advection in a finitely long channel and the distribution of an initial Gaussian pulse are employed to illustrate the accuracy and the efficiency of the method. Obtained results are compared with some early studies.

Ozlem Ersoy, Idris Dag

The coupled Burgers equation is solved by way of the trigonometric B-spline collocation method. The unknown of the coupled Burgers equation is integrated in time by aid of the Crank-Nicolson method. Resulting time-integrated coupled Burgers equation is discretized using the trigonometric cubic B-spline collocation method. Fully-integrated couupled Burgers equation which is a system of nonlinear algebraic equation is solved with a variant of Thomas algorithm. The three model test problems are studied to illustrate the accuracy of the suggested method.

Ozlem Ersoy, Idris Dag, Nihat Adar

The exponential cubic B-spline functions are used to set up the collocation method for finding solutions of the Burgers's equation. The effect of the exponential cubic B-splines in the collocation method is sought by studying four text problems.