• East Asian mathematical journal
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• 제34권1호
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• pp.69-84
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• 2018

In this paper, we study the viscoelastic Kirchhoff type equation with a nonlinear source for each independent kernels h and g with respect to Volterra terms. Under the smallness condition with respect to Kirchhoff coefficient and the relaxation function and other assumptions, we prove the uniform decay rate of the Kirchhoff type energy.

• 대한수학회보
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• 제43권2호
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• pp.245-252
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• 2006

In this paper we study the uniform decay estimates of the energy for the nonlinear wave equation of Kirchhoff type $$y'(t)-M({\mid}{\nabla}y(t){\mid}^2){\triangle}y(t)\;+\;{\delta}y'(t)=f(t)$$ with the damping constant ${\delta} > 0$ in a bounded domain ${\Omega}\;{\subset}\;\mathbb{R}^n$.

• East Asian mathematical journal
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• 제32권3호
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• pp.355-364
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• 2016

In this paper, we study exponential stabilization of the vibrations of the Kelvin-Voigt type wave equation with Balakrishnan-Taylor damping and acoustic boundary in a bounded domain in $R^n$. To stabilize the systems, we incorporate separately, the internal material damping in the model as like Kang [3]. Energy decay rate are obtained by the exponential stability of solutions by using multiplier technique.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제16권2호
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• pp.85-91
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• 2012

In this paper, we study uniform exponential stabilization of the vibrations of the Kelvin-Voigt type wave equation with acoustic boundary in a bounded domain in $R^n$. To stabilize the systems, we incorporate separately, the internal material damping in the model as like Gannesh C. Gorain [1]. Energy decay rates are obtained by the exponential stability of solutions by using multiplier technique.

• East Asian mathematical journal
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• 제28권3호
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• pp.339-345
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• 2012

In this paper, we study uniform exponential stabilization of the vibrations of the Kirchho type wave equation with acoustic boundary in a bounded domain in $R^n$. To stabilize the system, we incorporate separately, the passive viscous damping in the model as like Gannesh C. Gorain [1]. Energy decay rate is obtained by the exponential stability of solutions by using multiplier technique.

• East Asian mathematical journal
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• 제30권3호
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• pp.249-258
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• 2014

In this paper, we study uniform exponential stabilization of the vibrations of the Kirchhoff type wave equation with Balakrishnan-Taylor damping and acoustic boundary in a bounded domain in $R^n$. To stabilize the systems, we incorporate separately, the passive viscous damping in the model as like Kang[14]. Energy decay rates are obtained by the uniform exponential stability of solutions by using multiplier technique.

• Nuclear Engineering and Technology
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• 제29권4호
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• pp.320-326
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• 1997

The nuclide transport in the one-dimensional porous medium is considered as a first step in developing a decay chain transport in multidimensional inhomogeneous media. A method of solving conventional advection-dispersion equation with decay chain of arbitrary length by using the method of characteristics (MOC) is introduced. In specific cases where the advection are dominant rather than dispersion, the method is known to be useful : one of the most distinctive advantages in applying the model is that the MU minimizes the numerical dispersion, which is distinguished in such common numerical schemes as finite element method and finite difference method. The suggested model is considered to be effective through several illustrations for the case that decay chain of arbitrary length is involved during transport which is difficult to solve by standard numerical solutions if the medium becomes more complicated.

• 반도체디스플레이기술학회지
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• 제14권1호
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• pp.13-17
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• 2015

$YAlO_3:Tb{_x}^{3+}$ has been synthesized by a combustion process and the concentration x of Tb was varied from 0.001 and 0.05 mol% per mole of YAlO3. The energy transfer of $^5D_3{\rightarrow}^7F_6$(385nm) and $^5D_4{\rightarrow}^7F_5$(544nm) transitions on the $YAlO_3:Tb{_x}^{3+}$(x =0.001, 0.05) have been investigated by using decay curves. The energy transfer mechanism was explained by Inokuti and Hirayama model. The results of calculation and fitting showed that values of n are 6.11(x=0.01) and 6.13(x=0.005). These indicate that the energy transfer mechanism between $Tb^{3+}$ ions is dipole-dipole interaction.

• Nuclear Engineering and Technology
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• 제21권1호
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• pp.48-55
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• 1989

본 논고에서는 국내의 PWR 및 CANDU 사용후 핵연료로부터 발생하는 붕괴열의 장기적인 거동을 보다 손쉽게 분석하기 위하여 붕귀열을 추정할 수 있는 간단한 근사식을 도출하였다. 근사식의 장기적인 붕괴열 추정에서 ORIGEN 2코드 결과와의 차이를 줄이고 중요한 변수 조건하에서도 붕괴열을 추정할 수 있도록 하기 위하여 민감도 분석을 수행하였다. 그 결과로서 얻어진 근사식은 사용후 핵연료의 이력자료중 중요변수인 연도를 포함함으로써 3~500년정도의 냉각시간 범위내에서는 임의의 연소도를 가진 사용후 핵연료의 붕괴열이라도 추정할 수 있게 되었다. 그리고 대표적으로 30, 37 및 40 GWD/MTU등의 연소도를 갖는 사용후 핵연료의 붕괴열 추정에 있어서는 1년부터 $10^{5}$ 년까지의 냉각시간에 따라 ORIGEN2 ,코드의 결과와 $\pm$10%이내의 차이를 보이고 있어 사용후 핵연료 관리를 위한 관련시설의 열적설계 및 평가 등과 같은 공학적 목적에 유용하게 사용될 수 있을 것이다.

• 대한수학회지
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• 제49권6호
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• pp.1163-1174
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• 2012

This paper examines a temperature dependent Stokes flow in a semi-infinite cylinder. Under appropriate initial and boundary conditions the author establishes exponential decay of solutions in energy norm with distance from the finite end of the cylinder.