• Journal of applied mathematics & informatics
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• 제40권3_4호
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• pp.675-694
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• 2022

In this article, we investigate the solution of the inverse problem for one dimensional heat equation with Neumann and Robin boundary conditions, that is, we determine the temperature and source term with given initial and boundary conditions. Three radial basis functions(RBFs) have been used for numerical solution, and Homotopy perturbation method for analytic solution. Numerical solutions which are obtained by considering each of the three RBFs are compared to the exact solution. For appropriate value of shape parameter c, numerical solutions best approximates exact solutions. Furthermore, we have shown the impact of noisy data on the numerical solution of u and f.

• 대한수학교육학회지:학교수학
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• 제7권4호
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• pp.353-373
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• 2005

최근의 급속한 정보화 사회로의 전환에 편승하여 이산수학에 대한 관심과 이에 따른 연구가 활발해지고 있으며, 제 7차 교육과정에서 이산수학을 선택과목으로 지정할 만큼 그 중요성이 인정되고 있다. 본 연구는 네트워크문제와 관련된 이중계수 문제, 한붓그리기, 그리고 도로망문제를 중심으로, 초등 수학영재학생을 위한 학습프로그램을 구성하는 문제와 관련된 교수학적 변환에 대하여 논의하였다.

• 한국초등수학교육학회지
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• 제7권1호
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• pp.23-44
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• 2003

수학적 맥락 정보를 이용한 문제가 주어졌을 때, 학생들의 문제 해결 활동을 관찰하고 인지적 측면과 정서적 측면에서 분석하였다. 수학적 맥락 문제들은 Freudenthal의 수학 교육 이론과 RME에 따라 구성하였다. 그 결과, 개방된 형태의 맥락 문제가 보다 다양한 풀이를 산출해냄을 알 수 있었다. 따라서 교사는 스스로 형식적 수학을 재발명하고, 학생들로 하여금 그에 걸맞은 인지적 활동이 이루어지도록 나름대로의 교수 학습 방법을 개발하여야 한다.

• Korean Journal of Mathematics
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• 제6권2호
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• pp.173-181
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• 1998

The local behaviors of the Hopf bifurcation in the free boundary problem satisfying the zero flux boundary condition was examined in [3]. In this paper, we shall examine the global behaviors for this problem and shall apply the center-index theory to show the globality.

• 대한수학회논문집
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• 제38권3호
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• pp.925-935
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• 2023

In this paper, we consider a boundary value problem for a sixth order difference equation. We prove the monotone behavior of the eigenvalue of the problem as the coefficients in the difference equation change values and the existence of a positive solution for a class of problems.

• 대한수학교육학회지:수학교육학연구
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• 제8권1호
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• pp.237-249
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• 1998

Calculators can be instructional instruments to be used specially in problem situations which need calculations through calculators. A calculator-calculations is one of the various calculation methods. As there are problem situations for each method, there are problem situations for a calculator-calculation, too. Basically, calculator-calculations can be admitted in any cases which need not paper-and-pencil calculations, estimations, mental calculations, and computer-calculations. In this paper, some basic knowledges on how to use calculators in elementary mathematics education are offered. Students learn concepts easier by doing complex and tedious calculations through calculators than through paper-and-pencil calculations. And, by doing complex and tedious calculations in problem solving, they can focus on understanding problems, planning, and looking back. Calculator can be used directly in phases of understanding and planning. Calculators can be used to practice guess and check strategies. Problems which contain calculations beyond students' paper-and-pencil calculations abilities. So, as a result, students' experiences on problem solving can be extended. Calculators experiences can affect students' persistences, confidences, enthusiasms, self-esteems positively.

• Journal of applied mathematics & informatics
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• 제35권5_6호
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• pp.439-447
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• 2017

This paper investigates the inverse problem of determining an unknown heat radiative coefficient, which is only time-dependent. This is an ill-posed problem, that is, small errors in data may cause huge deviations in determining solution. In this paper, the existence and uniqueness of the problem is established by the second Volterra integral equation theory, and the method of trace-type functional formulation combined with finite difference scheme is studied. One typical numerical example using the proposed method is illustrated and discussed.

• Journal of applied mathematics & informatics
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• 제15권1_2호
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• pp.173-184
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• 2004

In this paper, we find the approximate solution of a second order nonlinear partial differential equation on a simple connected region in $R^2$. We transfer this problem to a new problem of second order nonlinear partial differential equation on a rectangle. Then, we transformed the later one to an equivalent optimization problem. Then we consider the optimization problem as a distributed parameter system with artificial controls. Finally, by using the theory of measure, we obtain the approximate solution of the original problem. In this paper also the global error in $L_1$ is controlled.

• 대한수학회지
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• 제54권5호
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• pp.1573-1594
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• 2017

This paper deals with the existence and energy estimates of solutions for a class of degenerate nonlocal problems involving sub-linear nonlinearities, while the nonlinear part of the problem admits some hypotheses on the behavior at origin or perturbation property. In particular, for a precise localization of the parameter, the existence of a non-zero solution is established requiring the sublinearity of nonlinear part at origin and infinity. We also consider the existence of solutions for our problem under algebraic conditions with the classical Ambrosetti-Rabinowitz. In what follows, by combining two algebraic conditions on the nonlinear term which guarantees the existence of two solutions as well as applying the mountain pass theorem given by Pucci and Serrin, we establish the existence of the third solution for our problem. Moreover, concrete examples of applications are provided.

• Journal of applied mathematics & informatics
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• 제16권1_2호
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• pp.307-321
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• 2004

In this paper, the unsteady Stokes problem is considered and also the pressure-correction method for the problem is described. At a fixed time level, we reduce the problem to two symmetric positive definite problems which depend on a time step parameter. Linear systems that arise from the problems are large, sparse, symmetric, positive definite and ill-conditioned as the time step tends to zero. Preconditioned problems based on an additive Schwarz method for solving the symmetric positive definite problems are derived and preconditioners are defined implicitly. It will be shown that the rate of convergence is independent of the mesh parameters as well as the time step size.