• Journal of the Korean Magnetics Society
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• v.22 no.3
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• pp.91-96
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• 2012

In this paper, a three-dimensional finite element model based on the multi-pixel was constructed to accurately predict electric field distributions including an interference phenomenon between adjacent pixels in the liquid crystal of a complicated TFT-LCD panel. Utilizing the elaborate numerical model, the characteristics of spatial electric field distributions depending on various fault-electrode conditions are thoroughly examined on the basis of the field distribution of a normal electrode condition. The validity of the proposed model is proved by comparing the simulation results with those of the existing optical inspection equipments.

• 대한치주과학회:학술대회논문집
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• 2005.11a
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• pp.167-167
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• 2005

• Journal of the Korea Concrete Institute
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• v.13 no.6
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• pp.637-644
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• 2001

A regularization method based on the Duvaut-Lions viscoplastic scheme for plastic-damage and continuum damage models, which provides mesh-independent and well-posed solutions in nonlinear earthquake analysis of concrete dams, is presented. A plastic-damage model regularized using the proposed rate-dependent viscosity method and its original rate-independent version are used for the earthquake damage analysis of a concrete dam to analyze the effect of the regualarization and mesh. The computational analysis shows that the regularized plastic-damage model gives well-posed solutions regardless mesh size and arrangement, while the rate-independent counterpart produces mesh-dependent ill-posed results.

• Journal of Korean Society of Disaster and Security
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• v.12 no.4
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• pp.43-52
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• 2019

To analyze the influence on the stability, resulting from application of upgrade pipe roof structure (UPRS) method to the structure existed under subway Station, physical properties of a ground, elasticity and elasto-plastic theories, including displacement analysis of finite elements, stress analysis of finite elements, displacement caused by steel pipe propulsion and internal excavation, and stress change in a steel pipe, were introduced. Then, the influence on structural stability when applying the UPRS method was compared and reviewed based on the construction management standard of the Ministry Land, Infrastructure and Transport and foreign sources, using numerical analysis with a model which assumes that each microelement divided into a structurally stable point consists of the connection of finite points. As a result of the finite element analysis, 7.21 mm maximum displacement, 1/3,950 angular displacement, 70.28 MPa bending compressive stress of steel pipe structure constructed with UPRS (non-excavation) method and 477.38 MPa maximum shear strength were within their allowable standards (25.00 mm, 1/500, 210.00 MPa and 120.00 MPa, respectively), and therefore, the results showed that the design and construction are stable.

• Explosives and Blasting
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• v.37 no.2
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• pp.1-13
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• 2019

In this study, Rock deformation on the splitting surface was investigated by using the finite element code relating to the blasting in urban area. The maximum principal strain according to the blasting detonation pattern was analyzed by the modeled blast section, and deformation of the splitting surface formed by the numerical analysis and the real blasting were compared. As a result, it was found that the maximum principal strain was observed a difference according to the blasting detonation pattern on the splitting surface, and the splitting surface was showed a similar waveform both the numerical analysis and the real blasting.

• Computational Structural Engineering
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• v.3 no.4
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• pp.91-104
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• 1990

Static performance of quadrilateral plate elements was compared through numerical experiments. Sixteen plate elements were selected for comparison from the literature, which were displacement elements, equilibrium elements, mixed elements or hybrid elements based on the Kirchhoff theory or the Mindlin theory. Thin plate bending problems, such as square plate problems, rhombic plate problems, circular plate problems and cantilevered plate problems, were modeled by various meshes and solved under various kinds of boundary conditions. Kirchhoff elements were not so good as Mindlin elements in view of efficiency and convergence. Hinton's elements resulted in the best results for the problems considered with respect to efficiency, convergence and reliability but in some problems they also resulted in more or less inaccurate solutions.

• 전기의세계
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• v.39 no.3
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• pp.47-54
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• 1990

유한요소법과 경계요소법의 합성으로 전자계 해석을 하는 기법은 각 방법의 장점을 수용하여 경계가 없는 무한영역의 전자장을 분석하는 기법으로서 어떤 복잡하고 어려운 기하학적 구조의 문제도, 비선형이나 비균질성 재질의 문제도 쉽게 formulation이 가능하여 용이하게 해석할 수 있지만 전체 System matrix방정식이 비대칭이며 부분적인 full matrix를 형성하여 계산시간이 길어 진다는 단점도 있다. 적용예에서 보여 준 것과 같이 합성요소법은 그 해가 실제에 근사한 값을 가질수 있다고 생각되며, 계산시간을 단축시키기 위하여 직접법이나 반복법을 사용한 새로운 해법들이 도입되고 있다. 최근에는 system전체 node의 순서를 고려한 NDRA(Nested Dissection Reordering Algorithm)이 도입되고 있고, System matrix자체를 유한 요소법의 형태로 유지시키며 풀수 있는 방법으로 알려진 Absorbin 경계조건을 사용하여 전자파에 대한 해석을 하고 있다. 유한 및 경계요소 합성법은 초고압 옥외용 전력기기의 전자장 해석과 설계, 레이다나 안테나 등의 전자파 해석문제, 초전도 응용, 전력기기의 전자장해석과 설계, 우주공간에서의 전력전송문제 등을 쉽게 model화하여 적용할 수 있을 것이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.137-141
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• 2006

컨테이너를 선박에 양 ${\cdot}$ 적하하는 장비인 컨테이너 크레인은 차폐물이 거의 없는 항만에 설치되며, 계류시 전체 높이가 100m에 달하게 되므로 풍하중에 매우 큰 영향을 받게 된다. 따라서 본 연구에서는 컨테이너 크레인에 작용하는 풍하중을 정확하게 분석하기 위하여 풍력실험과 유한요소해석, 전산유동해석을 통하여 컨테이너 크레인이 받는 풍하중을 분석하였다. 우선 대기 경계층 풍동을 이용한 풍력실험을 수행하여 풍향 및 기계시 위치에 따른 풍력계소를 측정하고, 이를 이용하여 컨테이너 크레인이 받는 풍하증을 분석하였다. 그리고 풍력실험에서 얻어진 반력비를 이용하여 유한요소해석을 수행함으로써 컨테이너 크레인에 작용되는 풍하증과 지지점에서의 전도력을 계산하였다. 마지막으로 전산유동해석을 수행함으로써 컨테이너 크레인 주위의 유동현상을 고찰하고 컨테이너 크레인 표면에서의 풍압력과 풍하중을 실험결과와 비교 ${\cdot}$ 분석하였다.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1906-1916
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• 1996

For the medical analysis of the three-dimensional structure such as the mandible, it is necessary to reconstruct the structure into the finite number of analyzable elements. The information of the three-dimensional structure can be obtained from the cross-sections of the magnetic resonance image (MRI). A region corresponding to the structure is extracted from the inner part of the cross- section. By the triangulation of the sampled cross-section image, two-dimensional finite elements are generated. Three-dimensional finite elements are constructed by matching the two dimensional finite elements each other in space. In this paper a construction method of the optimal three-dimensional finite elements has been suggested, which uses the adjacent information abstracted from the triangulated two-dimensional finite elements. The elements are classified into the identical property sets by using the adjacent information of the traingulated two-dimensional elements. After applying the multistep matching algorithm to the classified two-dimensional finite elements, the optimal three-dimensional finite elements can be construccted. By analyzing the constructed finite elements, it is possible to get much more useful medical information about the three-dimensional struture of mandible.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.294-302
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• 2018

To analyze the behavior of a soil beam under pore water pressure, the results of analytical solutions and finite element analysis (FEM) were compared quantitatively. In contrast to the results of the analytical solution, the horizontal stress obtained from the FEM did not show a symmetrical distribution. On the other hand, the horizontal stress became closer to symmetrical distribution as the number of elements of the soil beam were increased. A comparison of the horizontal stresses from the analytic solution with those obtained from Gaussian points of FEM showed that the magnitude of the tensile stress from the FEM using 3 elements was 6% of the maximum value of the analytical solution and the compressive stress from the FEM using the same elements was 37% of the maximum value of the analytical solution. The magnitude of the tensile stress from the FEM using 6 elements was 61% of the maximum value of the analytical solution and the magnitude of the compressive stress from the FEM using the elements was 83% of the maximum value of the analytical solution. Vertical stresses, which were obtained from the analytical solution, showed a continuous distribution with the depth of the soil beam, whereas the vertical stresses from the FEM showed a discrete distribution corresponding to each element. The results also showed that the average value of the vertical stresses of each element was close to that of the pore water pressure. A comparison of the vertical displacements computed at the near vertical center line of the soil beam from the FEM with those of the analytical solution showed that the magnitude of the vertical displacement from FEM using 3 elements was 35% of the value of the analytical solution and the magnitude of the vertical displacement from FEM using 6 elements was 57% of the value of the analytical solution.