• 한국초등수학교육학회지
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• 제21권4호
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• pp.643-662
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• 2017

초등학교 수학에서 등식은 덧셈식에서 등호를 기호와 말로 나타낼 때 용어에 대한 정의 없이 처음 제시된다. 대부분의 초등학교 학생들은 등식에서 나타나는 등호의 의미를 연산적으로 이해한다. 또한 교과서에서 연산의 성질이 암묵적으로 사용되어 학생들이 연산의 성질을 명확하게 이해할 수 있는 기회가 제한된다. 따라서 교과서에 특정한 수로 나타난 연산의 성질을 명시적으로 도입하는 것과 등호의 의미를 관계적으로 이해할 수 있는 다양한 맥락의 등식이 필요하다는 주장이 꾸준히 제기되어 왔다. 이에 본 연구에서는 초등학교 수학 교과서에 제시된 계산식을 등식으로 나타내어 암묵적으로 사용된 연산의 성질과 등호의 관계적 의미를 이해할 수 있는 방안을 학습자의 이해 수준에서 논의하고자 한다. 이와 더불어, 연산의 성질과 등호의 관계적 의미를 적용하여 효율적인 계산을 할 수 있는 구체적인 사례를 제시한다.

• Journal of the Korean Statistical Society
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• 제31권2호
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• pp.213-228
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• 2002

Asymptotic properties of minimum distance estimators for the parameter involved for a class of stochastic partial differential equations are investigated following the techniques in Kutoyants and Pilibossian (1994).

• 대한기계학회논문집
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• 제13권5호
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• pp.820-830
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• 1989

본 논문에서는 타이어의 각 부분의 물성치 계산을 위한 식을 유한요소법에 적용할 수 있도록 제안하였다. 이 식은 강철 코드의 굽힙효과를 고려 하였으며, 특히 각 요소에서 전단변형이 일어나는 동안의 굽힘효과를 고려하였다. 유한요소 공식화는 가상일의 원리에 의하여 평형 방정식으로부터 유도하였고, Updated refer- ence coordinate에 대해 증분해석을 적용하여 Updated Lagrangian공식화를 하였다. 그리고 차량하중에 의하여 타이어가 노면에 접지될때의 응력상태를 게산할 수 있도록 접촉문제 공식화를 유한요소 공식화에 첨가 하였다.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제22권4호
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• pp.315-331
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• 2015

The purpose of this paper is to obtain Opial-type inequalities that are useful to study various qualitative properties of certain differential equations involving impulses. After we obtain some Opial-type inequalities, we apply our results to certain differential equations involving impulses.

• Structural Engineering and Mechanics
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• 제66권5호
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• pp.557-568
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• 2018

An investigation is made in the present work on the post-buckling and geometrically nonlinear behaviors of moderately thick perfect and imperfect rectangular plates made-up of functionally graded materials. Spectral collocation approach based on Legendre basis functions is developed to analyze the functionally graded plates while they are subjected to end-shortening strain. The material properties in this study are varied through the thickness according to the simple power law distribution. The fundamental equations for moderately thick rectangular plates are derived using first order shear deformation plate theory and taking into account both geometric nonlinearity and initial geometric imperfections. In the current study, the domain of interest is discretized with Legendre-Gauss-Lobatto nodes. The equilibrium equations will be obtained by discretizing the Von-Karman's equilibrium equations and also boundary conditions with finite Legendre basis functions that are substituted into the displacement fields. Due to effect of geometric nonlinearity, the final set of equilibrium equations is nonlinear and therefore the quadratic extrapolation technique is used to solve them. Since the number of equations in this approach will always be more than the number of unknown coefficients, the least squares technique will be used. Finally, the effects of boundary conditions, initial geometric imperfection and material properties are investigated and discussed to demonstrate the validity and capability of proposed method.

• Bulletin of the Korean Chemical Society
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• 제24권9호
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• pp.1265-1268
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• 2003

The estimation of retention factors by correlation equations with physico-chmical properties maybe helpful in chromatographic work. The physico-chemical properties were water solubility (S), hydrophobicity (P), total energy ($E_t$), connectivity index 1 ($^1{\chi}$), hydrophilic-lipophlic balance (x) and hydrophilic surface area (h) of isoflavones. The retention factors were experimentally measured by RP-HPLC. Especially, the empirical regulations of water solubility and hydrophobicity were expressed in a linear form. The equation between retention factors and various physico-chemical properties of isoflavones was suggested as $k = a_0 + a_1\;log S + a_2log\;P^Q + a_3(E_t) + a_4(^1{\chi}) + a_5(x) + a_6(h)$, and the correlation coefficients estimated were relatively higher than 0.95. The empirical equations might be successfully used for a prediction of the various chromatographic characteristics of substances, with a similar chemical structure.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제17권3호
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• pp.249-256
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• 2010

We research the properties of solutions of general higher order homogeneous linear differential equations and apply the hyper order to obtain more precise estimation for the growth of solutions of infinite order.

• Journal of applied mathematics & informatics
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• 제37권5_6호
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• pp.491-506
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• 2019

In this paper, we show the existence and uniqueness of solution to stochastic differential equations under weakened $H{\ddot{o}}lder$ condition and a weakened linear growth condition. Furthermore, the properties of their solutions investigated and estimate for the error between Picard iterations $x_n(t)$ and the unique solution x(t) of SDEs.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제26권4호
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• pp.224-243
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• 2022

In this paper, we prove the global existence of classical solutions to the 2D incompressible Boussinesq equations for the micropolar fluid. Furthermore, applying the Fourier splitting methods, we obtain the lager time decay properties.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제25권1호
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• pp.16-25
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• 2021

This paper is studied the existence of a solution for the impulsive Cauchy problem involving the Caputo fractional derivative in Banach space by using topological structures. We based on using topological degree method and fixed point theorem with some suitable conditions. Further, some topological properties for the set of solutions are considered. Finally, an example is presented to demonstrate our results.