• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.326-330
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• 2007

Bumper back beam is one of the essential structural components of front-end module. It should be designed to withstand a minor bump in low-speed collision, 2.5 mph crash test for example. And weight reduction is always important problem in the design of almost all the parts in car for energy saving. So, the key issues in shape design of a bumper are weight reduction and the performance in 2.5mph crash test. In this study, a light weight and high performance bumper back beam model was developed using analytical approach based on mechanics and FE simulation together.

• Geomechanics and Engineering
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• v.5 no.2
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• pp.165-185
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• 2013

In the present study, the numerical and experimental investigations were performed on the backfill- exterior wall-fluid interaction systems in case of empty and full tanks. For this, firstly, the non-linear three dimensional (3D) finite element models were developed considering both backfill-wall and fluid-wall interactions, and modal analyses for these systems were carried out in order to acquire modal frequencies and mode shapes by means of ANSYS finite element structural analysis program. Secondly, a series of field tests were fulfilled to define their modal characteristics and to compare the results from proposed approximation in the selected structures. Finally, comparing the theoretical predictions from the finite element models to results from experimental measurements, a close agreement was found between theory and experiment. Thus, it can be easily stated that experimental verifications provide strong support for the finite element models and the proposed procedures themselves are the meritorious approximations to the real problem, and this makes the models appealing for use in further investigations.

• Journal of Magnetics
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• v.17 no.2
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• pp.129-132
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• 2012

To evaluate the electromagnetic power absorption in near field, the magnetic composites with the conductive grids were simulated using the typical permeability frequency profiles. The transmission power absorptions of the magnetic composites on microstrip line were extracted by the 3D FEM simulation program of HFSS. The magnitudes of power absorptions were greatly enhanced up to 98% and broadened the absorbing frequency band over 5 GHz by the insertion of a conductive grid in magnetic composite. The initial frequency of the power absorption can controlled by the change of the ferromagnetic resonance frequencies of the magnetic composite.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.37-40
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• 1989

When we analyze the magnetostatic problem by the FEM, it is a traditional method to use the magnetic vector potential as an unknown variable.(abbreviated to A Method) Therefore, we should differentiate this magnetic vector potential to get the magnetic flux density. In this procedure of differentiation, the accuracy of the calculation is reduced. In order to overcome this problem, this paper uses the magnetic flux density as an unknown variable.(abbreviated to B Method) The validity of this new method (B Method) to use the magnetic flux density directly as an unknown variable, is ensured as the result of the application example researches.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.358.2-358
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• 2002

To improve the driving sensitivity of an optical pickup actuator for high density and high speed drive, we present a new actuator design using multipolar flux-density distribution by magnetic materials and Nd-Fe-B sintered magnets. We expect this actuator to use in 3-axis actuator fur tilt compensation as well as conventional 2-axis actuator. The electromagnetic field analysis applying 3-D FEM was performed and several samples were actually tested. From comparing simulated data with experimental results, we verified theaccuracy of the simulation and the superiority of the presented method.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1456-1457
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• 2008

본 논문에서는 박막 PZT(Pb(Zr,Ti)O3)를 이용한 d33모드의 자가 발전 소자를 설계 및 제작 하였다. 자가 발전 소자는 진동 에너지를 압전 현상을 통해 전기 에너지로 변환하는 소자로서, 제안한 구조는 단일 외팔보가 아닌 20개 이상의 외팔보를 원형으로 집적한 구조를 갖기 때문에, 기존의 단일 외팔보 위주의 자가발전 소자보다 출력 전력이 우수하다. 자가 발전 소자의 성능 최적화를 위해 유한요소기법(FEM)을 통해 기계적 특성을 분석하였으며, 마이크로 머시닝 기법을 이용하여 초박형의 자가 발전 소자를 제작할 수 있었다. 제작된 자가발전 소자는 $1.2mm\times1.2mm\times0.5mm$ (높이)의 크기를 갖는다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.680-681
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• 2015

This paper proposes a comparative study of dual-airgap flux switching permanent magnet (FSPM) and spoke-type interior permanent magnet (S-IPM) machines equipped with phase-group concentrated-coil (PGCC) windings. Both of the investigated machines are the same size and material amounts which are compared at the same operating conditions. All the relevant machine performance including back electromotive force (EMF), cogging torque, and electromagnetic torque are analyzed by a 2-D time-stepping finite element method (FEM).

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.2
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• pp.56-62
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• 1999

This paper is concerned with the design and the construction of a moving magnet type linear DC motor(MM type LDM) for instrumentation. A mathematical model for the design of a LDM is developed and a permeance method is used to calculate the effective flux density in the air gap. The flux distribution in the air gap is analyzed and the width of iron core should be determined in order not to saturate the iron core by caluclating maxmum flux density. The design data culculated by a permeance method are compared with the analyzed results using FEM(MAXWELL 2D). The errors between two results are corrected. The tested LDM is constructed using the corrected design data. The results of experiment for thrust characteristics are compared with simulation.

• The Journal of Engineering Geology
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• v.26 no.2
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• pp.169-175
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• 2016

Estimations of regional stress are demonstrated in this paper. Firstly, regional stress is defined and the characteristics of regional stress are then discussed based on the local stresses measured by the Compact Conical-ended Borehole Overcoring (CCBO) technique and the results from the earthquake focal mechanism. Secondly, the regional stresses are estimated by a back analysis of three-dimensional finite element models, using the local stresses measured by the CCBO and hydraulic fracturing.

• Transactions of Materials Processing
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• v.9 no.2
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• pp.152-158
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• 2000

A finite element analysis has been performed to investigate the effect of die clearance on shear planes in the fine blanking of a part of automobile safety belt. For the analysis, S45C is selected as an material, which is used in manufacturing the part of automobile safety belt, and Cockcroft-Latham fracture criterion is applied. Effect of die Clearance on die-roll width, die-roll depth, burnish zone, and fracture zone has been investigated in the finite element analysis by a rigid-plastic FEM code, DEFORM-2D. From the analysis, it has been found that die-roll depth and depth of the shear plane increase with increasing die clearance. And the burnish zone decreases with increasing die clearance, but the variation of fracture zone is opposite to that of burnish zone because the increase in die clearance requires less fracture energy. Theoretical predictions are compared with experimental results. There is a good agreement between theory and experiment.