• Nuclear Engineering and Technology
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• v.20 no.3
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• pp.197-202
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• 1988

A finite slab approximation method was developed to predict the long-term teachability. It is based on the assumption that the diffusional characteristics of radionuclides in a waste matrix are not dependent on matrix geometry but dependent on volume to surface ratio V/S) and diffusion coefficient. Consequently it can be expressed as the solution of the equations obtained from a finite slab with an equal V/S ratio (imaginary diffusion length). The calculational results by the finite slab approximation method have been compared with the results obtained for finite cylinder and sphere with corresponding diffusional analysis. The results of this simple model have showed a good agreement and presented a general applicability for the long-term prediction of the radionuclide leaching behavior.

• 대한치과보철학회:학술대회논문집
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• 1997.11a
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• pp.25-25
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• 1997

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.207-207
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• 2003

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.3
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• pp.129-138
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• 1993

In this study, the applicability of finite analytic method (FAM) is studied by selecting linearized-Burgers equation and Burgers equation which have convective and diffusive behaviors as the model equation of Navier-Stokes equations and by comparing numerical solution of finite difference method (FDM) and finite analytic method. The results are as follows. It is shown that the convergence of FAM for steady-state analytic solution of linearized-Burgers equation and Burgers equation is better than that of FDM under the same criteria. Also the accuracy of FAM for transient solution of Burgers equation is excellent. Especially, it is shown that oscillation phenomenon due to dispersion errors which occur according to the choice of grid size in FDM does not occur in FAM at all. So, it can be thought that FAM is numerically very stable scheme, which is free from dispersion errors.

• Composites Research
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• v.30 no.6
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• pp.338-342
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• 2017

In this paper, evaluation method of structural integrity of cylindrical composite lattice structures was conducted. A finite element analysis was used to evaluate the structural integrity of composite lattice structures. In order to verify the optimal finite element in the evaluation of the structural integrity, finite element models for cylindrical composite lattice structure were generated using beam, shell and solid elements. The results of the finite element analyses with the shell and solid element models showed a good agreement. However, considerable differences were found between the beam element model and the shell and solid models. This occurred because the beam element does not take into account the degradation of the mechanical properties of the non-intersection parts of cylindrical composite lattice structures. It was found that the finite element analysis of evaluation of structural integrity for cylindrical composite lattice structures have to use solid element.

• Computational Structural Engineering
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• v.7 no.2
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• pp.111-120
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• 1994

Cracks in rubber bonded to a rigid material such as steel are analyzed with the aid of a mixed finite element technique. Firstly the weak form is derived for finite element analysis of an incompressible material, and the Mooney-Rivlin form is assumed for the constitutive modeling of rubber. The numerical results from finite element analysis is examined to confirm the accuracy and convergence of solution by way of comparison to other numerical results. The interpretation of the J-integral for large elastic deformation as the energy release rate is confirmed, and the J-integral is calculated for varing crack length. The crack growth stability is discussed using the result of finite element analysis.

• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.143-149
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• 2006

This paper deals with the space-time finite element analysis of two-dimensional vibration problem with a single variable. The method of space-time finite elements enables the simpler solution than the usual finite element analysis with discretization in space only. We present a discretization technique in which finite element approximations are used in time and space simultaneously for a relatively large time period. The weighted residual process is used to formulate a finite element method for a space-time domain. A stability problem is described and some investigations for chosen type of rectangular space-time finite elements are carried out. Instability is caused by a too large time step of successive time steps in the traditional time-dependent problems. It has been shown that the numerical stability of time-stepping on the larger time steps is quite good. The unstructured space-time finite element not only overcomes the shortcomings of the stability in the traditional numerical methods, but it is also endowed with the features of an effective computational technique. Some numerical examples have been presented to illustrate the efficiency of the described method.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.4
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• pp.727-739
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• 2002

Based on a generalized variational principle for magneto-thermo-elasticity, a theoretical model is proposed to describe the coupled magneto-thermo-elastic interaction in soft ferromagnetic plates. Using the linearized theory of magneto-elasticity and perturbation technique, we analyze the magneto-elastic and magneto-thermo-elastic instability of simply supported ferromagnetic plates subjected to thermal and magnetic fields. A nonlinear finite element procedure is developed next to simulate the magneto-thermo-elastic behavior of a finite-size ferromagnetic plates. The effects of thermal and magnetic fields on the magneto-thermo-elastic bending and buckling is investigated in some detail.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.666-669
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• 1996

기계 부품 응력 해석 시 널리 쓰이는 유한 요소 해법은 형상을 작은 유한 요소로 근사화하는 과정이 필요하다. 유한 요소생성의자동화는 많은 기존 연구가 있었고 산업 현장에서도 실질적인 자동 유한 요소 생성의 혜택을 받고있다. 이러한 자동 유한 요소 생성 알고리즘들은 형상을 충실하게 유한 요소로 근사화 하는데 그목적이 있다. 때로는 이러한 충실성이 너무 많은 유한 요소들을 관심 영역이 아닌 곳에 생성하게 된다. 컴퓨터의 계산 능력이 눈부시게 발전하고 있지만 기술자가 다루고자 하는 기술적인 문제가 나날이 복잡해지고있는 상황에서 컴퓨터의 계산 능력에 너무 의존하는 것은 바람직하지 않다. 본 논문은 지능과 유사하게 미소 특징을 추출하고 이를 바탕으로 기하 형상 에서 미소 특징을 소거하는 알고리즘을 소개한다. 이를 활용하면 유한 요소의 수를 해석 결과에 악 영향을 미치지 않는 상태에서 줄일 수 있으며, 결과적으로 불필요한 계산비용을 절감할 수 있다.

• Journal of the Society of Disaster Information
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• v.12 no.1
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• pp.69-73
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• 2016

In this study, the applicability and validity of collocation method to nonlinear vibration issues in comparison to other solutions are confirmed, and the applicability of collocation method to nonlinear dynamic response issues in comparison to the response curve with F.E.M results is examined. Also, it is also examined how the influence of axial inertia varies according to the size of slenderness ratio.