• Proceedings of the KIEE Conference
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• 2008.04c
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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.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.172-174
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• 1996

In this paper, the characteristics of single-phase induction motors is studied using TDFE(Time Domain Finite Element) analysis. The magnetic field equation from the Maxwell's equations is solved using 2-Dimensional TDFE method, and the circuit equations from the stator and rotor are solved simultaneously. The 3-D effects, which are the end-leakage reactance and the resistance of end-rings are considered in 2-D combined equations. The proposed method is applied to the commercial single-phase induction motor. The calculated waveforms of the currents shows a good agreement with the measured ones.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.60-62
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• 2003

본 연구는, 초고압 GIS(Gas Insulated Switchgear)용 GCB(Gas Circuit Breaker)의 3상 배치구조를 설계 하기 위한 상간, 대지간의 절연성능을 평가하였다. 피임펄스 전압과 상용주파 전압인가시 상간, 대지간의 절연설계 기준과 비교하여 절연설계 안전율을 고려하여 설계에 적용하였다. 수치적 전계 해석법으로 3차원 전계 해석법과 2차원 축대칭 전계 해석법을 통해 전계 강도를 비교하였으며 3차원 전계 해석법으로는 경계 요소법(Boundary Element Method)을 사용하는 상용프로그램인 coulomb을 사용하였으며, 2차원 전계 해석법으로는 유한요소법(Finite Element Method)을 사용하는 Maxwell을 통해 절연성능 평가를 하였다. 마지막으로, 전계 해석을 통해 절연설계 기준에 적합한 상배치 구조 설계를 하였다.

• Korean Journal of Optics and Photonics
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• v.4 no.2
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• pp.173-180
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• 1993

We observed Ramsey resonance signals from an optically pumped cesium atomic clock and compared them with the theoretical results calculated from the Ramsey transition probabilities. The theoretical results were in good agreement with the experimental results when the weighting factor of $1/{\nu}$ was taken into account to the Maxwellian distribution of velocities in the atomic beam. It was also found that the clock transition signal of Rabi-Ramsey spectra can be greatly enhanced by using two lasers with the proper polarizations as pumping sources of cesium atoms.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.304-307
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• 2003

Usually, the thrust of a Linear Pulse Motor(LPM) is calculated by magnetic equivalent circuit modelling method. Analytical thrust deviation exists to calculating magnetic flux density by using Permeance Modelling Method, Finite Element Method, and Velocity Electric Motive Force method. For calculating accuracy thrust by using these every method, tire thrust is calculated and compared by Lorentz Force method, Magnetic coenergy Method, and Maxwell correspondence forte Method. And that becomes Important factor at the comparison of each capacity and parameter of motor. So this study wants to compare and analyze measurement data and calculating data of the static thrust of LPM. and then we can get more accuracy method, calculating the static thrust of LPM.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.6
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• pp.622-634
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• 2003

This paper is concerned with a computational method for recovering a crack shape of steam generator tubes of nuclear plants. Problems on the shape identification are discussed arising in the characterization of a structural defect in a conductor using data of eddy current inspection. A surface defect on the generator tube ran be detected as a probe impedance trajectory by scanning a pancake type coil. First, a mathematical model of the inspection process is derived from the Maxwell's equation. Second, the input and output relation is given by the approximate model by virtue of the hybrid use of the finite element and boundary element method. In that model, the crack shape is characterized by the unknown coefficients of the B-spline function which approximates the crack shape geometry. Finally, a parameter estimation technique is proposed for recovering the crack shape using data from the probe coil. The computational experiments were successfully tested with the laboratory data.

• 전기의세계
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• v.24 no.2
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• pp.63-70
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• 1975

The solid-iron rotor induction motor is the squirral cage type induction motor with its rotor core consisting of solid iron in stead of a laminated core. The specific feature of this motor are that its structure is simple and firm, and therefore provides the great convenience in its operation and that its starting characteristic are excellent. this study is aimedto derive the equation for theroretical evaluation of the speed-torque characteristics of the motor by use of maxwell's equation. Through the series of test on the speed-torque characteristics of this motor which is experimentally constructed, we have proved the feasibility of the equaiton which is derived theoretically to calculate the torque of the motor. In addition we have obtained its general charastristics experimentally.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.101-104
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• 2000

The general solution of the anti-plane shear problem for the curved interfacial crack between viscoelastic foam and composites was investigated with the complex variable displacement function and Kelvin-Maxwell model. The Laplace transform was applied to treat the viscoelastic characteristics of foam in the analysis. The stress intensity factor near the interfacial crack tip was predicted by considering both anisotropic and viscoelastic properties of two different materials. The results showed that the stress intensity factor increased with increasing the curvature of the curved interfacial crack and it also increased and eventually converged to a specific value with increasing time.

• Journal of the Korean Ceramic Society
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• v.28 no.10
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• pp.785-792
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• 1991

An investigation of the crack propagation behavior of Al2O3-33Vol.% SiCw at 140$0^{\circ}C$ was conducted with various loading frequencies. Higher crack propagation was observed in lower frequency and higher load ratios. Interface sliding fracture due to glassy phase from the oxidation of SiCw and cavitation along grain boundary of diffusional creep appeared to be the main mechanism of fatigue fracture in slower crack propagation while interface sliding and whisker pull out aided by glassy phase formation played main role of fatigue fracture for higher crack growth condition. The frequency effect on deformation behavior was discussed with a Maxwell model.

• Journal of Environmental Science International
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• v.18 no.8
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• pp.911-918
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• 2009

Electromagnetic interference (EMI) is defined as the interaction phenomena of electromagnetic waves scattered from a large structure or complex terrain. In this study, the propagation of linear wave is modeled with ray theory, direct simulation Monte Carlo (DSMC), and some classical theories on flat plates. The wave physics of reflection, refraction, and diffraction are simulated for the investigation of front and back scattering of the one-dimensional plane wave from a tower with ray theory and DSMC, respectively. The effect of rotating disk idealized from the real wind-turbine blades is modeled with a simplified version of the classical electromagnetic theory as well as DSMC based on the ray theory.