• 한국지반공학회논문집
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• 제22권4호
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• pp.5-10
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• 2006

반무한 영역을 유한영역에 사영한 다음 반무한지반의 비선형동적응답해석에 대한 특수한 유한 차분법을 제안하였다. 해석대상의 주요 부분은 동일 길이로 하고, 주변은 축소, 사영함으로서 무한영역을 유한영역으로 변환 후 차분하였다. 우선 반무한 지반의 선형모델의 응답으로서 계산값과 이론값의 결과를 비교하였다. 선형모델에 대한 제안법의 계산결과는 Lamb의 해석결과와 양호하게 일치했다. 또 간단한 모델에 의한 선형, 비선형해석도 소규모 mesh에 의한 응답결과와 대규모 mesh에 의한 응답결과는 일치하고 제안법의 유효성을 나타내었다.

• 한국산업융합학회 논문집
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• 제5권4호
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• pp.309-312
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• 2002

Motivated by the problem of steady-state heat conduction in a rod whose heat flux at one end is determined by observation of the temperature and heat flux at some point ${\xi}$ in the interior of the rod, we consider the problem y"(x)=a(x, y(x))y(x) (0$${\lim_{x{\rightarrow}{\infty}}}y(x)=0,\;y^{\prime}(0)=g(y({\xi}),\;y^{\prime}({\xi}))$$ for some fixed ${\xi}{\in}(0,{\infty})$. We establish conditions guaranteeing existence and uniqueness for this problem on the semi-infinite interval [0,${\infty}$).

• Korean Journal of Mathematics
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• 제30권3호
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• pp.475-489
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• 2022

This paper focuses on a robust semi-infinite interval-valued optimization problem with uncertain inequality constraints (RSIIVP). By employing the concept of LU-optimal solution and Extended Mangasarian-Fromovitz Constraint Qualification (EMFCQ), necessary optimality conditions are established for (RSIIVP) and then sufficient optimality conditions for (RSIIVP) are derived, by using the tools of convexity. Moreover, a Wolfe type dual problem for (RSIIVP) is formulated and usual duality results are discussed between the primal (RSIIVP) and its dual (RSIWD) problem. The presented results are demonstrated by non-trivial examples.

• Journal of applied mathematics & informatics
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• 제18권1_2호
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• pp.205-228
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• 2005

Let I(f) be the integral defined by : $I(f) = \int\limits_{a}^{b} f(x)w(x)dx$ with f a given function, w a nonclassical weight function and [a, b] an interval of IR (of finite or infinite length). We propose to calculate the approximate value of I(f) by using a new scheme for deriving a non-linear system, satisfied by the three-term recurrence coefficients of semi-classical orthogonal polynomials. Finally we studies the Stability and complexity of this scheme.

• 대한수학회보
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• 제54권6호
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• pp.2065-2079
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• 2017

This paper is devoted to the minimal and maximal bounded solutions for general time interval quadratic backward stochastic differential equations with stochastic conditions. A general existence result is established by the method of convolution, the exponential transform, Girsanov's transform and a priori estimates, where the terminal time is allowed to be finite or infinite, and the generator g is allowed to have a stochastic semi-linear growth and a general growth in y, and a quadratic growth in z. This improves some existing results at some extent. Some new ideas and techniques are also applied to prove it.

• International Journal of Air-Conditioning and Refrigeration
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• 제6권
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• pp.14-26
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• 1998

This paper deals with approximate analytical solutions for the two-region one-dimensional model describing the charging process of stratified thermal storage tanks at variable inlet temperature with momentum-induced mixing. An arbitrarily increasing inlet temperature is decomposed into inherent step changes and intervals of continuous change. Each continuous interval is approximated as a finite number of piecewise linear functions, which admits an analytical solution for perfectly mixed region. Using the Laplace transform, the temperature profiles in plug flow region with both the semi-infinite and adiabatic ends are successfully derived in terms of well-defined functions. The effect of end condition on the solution proves to be negligible under the practical operating conditions. For a Quadratic variation of inlet temperature, the approximate solution employing a moderate number of pieces agrees excellently with the exact solution.