• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 추계학술대회 논문집
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• pp.55-61
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• 2000

Tungsten heavy metal is characterized bi a high density and novel combination of strength and ductility. Among them, 90W-7Ni-3Fe is used for applications, where the high specific weight of the material plays an important role. They are used as counterweights, rotating inertia members, as well as for defense purposes(kinetic energy penetrators, etc.). Because of these applications, it is essential to detemine the dynamic characteristics of tungsten alloy. In this paper, Explicit FEM(finite element method) is employed to investigate the dynamic characteristics of tungsten heavy metal under base of stress wave propagation theory for SHPB, and the model of specimen is divided into two parts to understand the phenomenon that stress wave penetrates through each tungsten base and matrix. This simulation results were compared to experimental one and through this program the dynamic stress-strain curve of tungsten heavy metal can be obtained using quasi static stress-strain curve of pure tungsten and matrix.

• 전자공학회논문지D
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• 제36D권7호
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• pp.26-33
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• 1999

4빔 브릿지형 압저항형 실리콘 가속도 센서에서 빔의 위치가 가속도 센서의 특성에 어떤 영향을 주는지 조사하기 위해서 빔의 위치가 서로 다른 3가지 형태의 가속도 센서를 FEM(finite element method)을 사용하여 해석하고, SDB(silicon direct bonding) 웨이퍼를 사용하여 RIE(reactive ion etching)와 KOH(potassium hydroxide) 애칭 공정으로 제조하였다. 세가지 형태의 가속도 센서에 대한 FEM 해석 경과, 첫 번째 공진 주파수와 Z축 감도는 세구조 모두 같게 나타났으나, 두 번째와 세 번째의 공진 주파수 및 X, Y축의 감도는 다른 것으로 나타났다. 제조된 가속도 센서의 특성을 살펴볼 때, 세 가지 형태의 센서는 비록 첫 번째 공진 주파수와 Z축 감도가 정확하게 일치하지는 않았지만, 첫 번째 공진 주파수는 1.3 ~ 1.7 KHz, Z축 감도는 5 V 인가시 180 ~ 220 lN/G, 타축감도는 1.7 ~ 2 %를 가지는 것으론 나타났다.

• 한국터널지하공간학회 논문집
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• 제15권3호
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• pp.345-356
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• 2013

본 연구에서는 SPH(Smoothed Particle Hydrodynamics) 코드를 사용하여 TBM에 장착되는 디스크커터에 의한 암석의 절삭과정을 모사하였다. 이를 위하여 본 연구에서는 3차원 FEM 해석 상용프로그램인 AUTODYN3D를 사용하였으며 이를 통해 국내 황등화강암을 대상으로 총 25개의 절삭조건에 대한 수치적인 절삭시험을 수행하였다. 암석과 디스크커터를 각각 라그란지안 솔버와 SPH 솔버를 사용하여 3차원 형상으로 모델링 하고 두 개의 디스크커터가 순차적으로 암석을 절삭하도록 모델링 하였다. 수치해석과 LCM시험에서 측정한 디스크커터의 작용력은 오차 10%이내의 값을 보여 대체로 일치하는 것으로 나타났고 균열의 전파양상과 암석의 파쇄양상 또한 유사한 것으로 나타났다. 또한 절삭된 최적 커터간격을 측정한 결과 LCM시험 결과와 일치하였다. 이를 통해 SPH코드를 사용한 수치해석기법의 적용성을 확인할 수 있었으나 해석시간을 단축하기 위한 Lagrange-SPH코드의 커플링에 관한 후속연구가 필요할 것으로 판단되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.245-246
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• 2008

In this paper we calculated and compared the arc driving force of two spiral-tyre vacuum interrupter electrode models which have 3petals and 4petals respectively by means of commercial finite element method software Maxwell 3D. As a result we can find that the more petals the electrode has, the stronger arc driving force was generated. This simulation method can contribute to optimization of spiral-type electrode designs in a view of arc driving force.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제12B권1호
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• pp.13-18
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• 2002

Novel method to calculate flux linkage for 3-D finite element analysis is proposed. It does not require any integral path if the current direction in a coil is known. The flux linkage can be calculated very easily using simple volume based integration. The current direction is calculated based on the recently developed technique by the authors. The novel method for flux linkage calculation is verified by applying to a very complicated deflection yoke coil. The simulation result is compared to the experimental one. From the simulation, it is shown that the proposed method is very accurate and effective to calculate the flux linkage of a coil.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1741-1743
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• 1996

This paper presents simulations of the pancake in the simplified 3D microwave oven. The results were compared with experimental data. For the comparison we used infrared photography of the heated pancake and electric field distribution obtained by simulation. Finite Element Method (FEM) using edge element is employed for the simulation. For solving the large sparse system parallelled QMR method was used.

• 조명전기설비학회논문지
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• 제28권9호
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• pp.28-34
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• 2014

A claw pole stepping motor is widely used in various fields such as a compact optical disk drive, computer peripherals, digital cameras, office automation(OA), handheld mobile devices, because it has the suitable structure for compact motor. However 3D analysis is essential for design of Claw pole stepping motor because of axial flux path. Thus, in general, it takes a lot of time in the design of Claw pole motor. In this paper, magnetic equivalent circuit considering axial flux was proposed to reduce design time of Claw pole motor and we has designed by using the magnetic equivalent circuit. In addition, in oder to verify the study, design model was verified by 3D FEM simulation and experiment.

• Ocean Systems Engineering
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• 제9권1호
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• pp.21-42
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• 2019

In this paper, the Finite-Analytic Navier-Stokes (FANS) code is coupled with an in-house finite-element code to study the dynamic interaction between a floating buoy and its mooring system. Hydrodynamic loads on the buoy are predicted with the FANS module, in which Large Eddy Simulation (LES) is used as the turbulence model. The mooring lines are modeled based on a slender body theory. Their dynamic responses are simulated with a nonlinear finite element module, MOORING3D. The two modules are coupled by transferring the forces and displacements of the buoy and its mooring system at their connections through an interface module. A free-decay model test was used to calibrate the coupled method. In addition, to investigate the capability of the present coupled method, numerical simulations of two degree-of-freedom vortex-induced motion of a CALM buoy in uniform currents were performed. With the study it can be verified that accurate predictions of the motion responses and tension responses of the CALM buoy system can be made with the coupling CFD-FEM method.

• 전기학회논문지
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• 제58권3호
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• pp.573-577
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• 2009

Piezoresistive pressure sensor have become the successfully-commercialized MEMS product and the related technologies have been well developed over the past decades. Regarding the design methodology, however, the coupled-physics FEM analyses of the transducer itself and the signal-processing circuitry design based on the conventional EDA are separated and both of the analyses were sequentially processed for the full design of the pressure sensor. For the fast and effective R&D, new design methodology is proposed in this paper where the FEM results are linked to the EDA environment and therefore most of the design works can be done in the EDA environments, which means the time-consuming FEM analyses can be minimized. In order to verify the proposed approach, a typical piezoresistive pressure sensor having the silicon diaphragm and piezoresistors was modeled and analyzed based on the proposed methodology. The verification results showed that the simulated results were matched well with the measured data within the 7% difference while the simulation time was reduced less than 5% compared to the conventional methodology. Through the proposed approach, various types of the piezoresistive pressure sensors can be developed in more effective way.

• 한국자기학회지
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• 제21권3호
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• pp.99-103
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• 2011

본 연구에서는 유한요소해석을 이용하여서 양쪽 끝이 열린 형상을 가진 원통형 3층 자기 실드를 설계하기 위한 해석을 수행하였다. 원통형 자성체의 투자율 범위 $2{\times}10^3\sim1{\times}10^5$에서 자기 차폐율을 검토하였고, 자성체의 길이 및 각 층간의 길이 차에 의한 자기 차폐율의 변화를 해석하였다. 투자율이 $2{\times}10^4$ 이상이고 각 층의 길이가 40 cm, 45 cm, 50 cm인 경우 -60 dB 이상의 자기 차폐율을 얻을 수 있었으며, 이때의 균일 자계 영역은 $10cm{\times}10cm-\phi$ 이상이었다.