• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1142-1145
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• 2006

The Finite-difference time-domain (FDTD) method is used to directly solve Maxwell's equations, and the techniques required for optical simulation of Bragg reflections of cholesteric liquid crystal (ChLC) displays are introduced in this paper. The simulated results show that the color gamut of a ChLC display can be broadened by using of a circular polarizer on top surface of the ChLC film, and are examined by experiments.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1089-1093
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• 2003

The moving least square (MLS) basis is implemented for the real-space band-structure calculation of 2D photonic crystals. The value-periodic MLS shape function is thus used in order to represent the periodicity of crystal lattice. Any periodic function can properly be reproduced using this shape function. Matrix eigenequations, derived from the macroscopic Maxwell equations, are then solved to obtain photonic band structures. Through numerical examples of several lattice structures, the MLS-based method is proved to be a promising scheme for predicting band gaps of photonic crystals.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.37.1-37.1
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• 2017

We consider a magnetic dipole model of a pulsar and investigate general relativistic effects on electromagnetic radiation from the pulsar. The general relativistic modifications should be found applicable to many well-known issues in pulsar astronomy. Among other things, the modifications of Goldreich-Julian model and subpulse drift would be of significant interest and challenging issues. The electromagnetic fields in the pulsar magnetosphere are computed by solving Maxwell's equations defined in the strongly curved spacetime around the pulsar, hence containing the properties of strong gravitational effects. On top of these effects, we also investigate the effects from rotation and obliqueness of the pulsar to work out the general relativistic versions of Goldreich-Julian model and subpulse drift.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.36-38
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• 1995

A Single-phase condensor motor is analyzed by FEM coupled with external circuit. The finite element analysis is based on the solution of combined equation both the magnetic field equation from the Maxwell's and the circuit equations of the stator and rotor circuit. The external circuit of the single-phase condensor motor to be analyzed is described using FLUX2D and linked to multiple FEM regions. The simulated results show that the condensor motor analysis with external circuit has good agreement with those of test results.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.742-743
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• 2015

Magnetic couplings are do not require any mechanical contact with the power transmitted to the secondary side according to the primary side. For this reason, well-suited for isolated systems such as vacuums or high pressure. So, this paper presents the force characteristic analysis of the permanent magnet (PM) linear coupling with vertical magnetized using an analytical magnetic field calculations. Based on the definition of governing equations and magnetic vector potential, we obtained the analytical solutions according to the boundary condition for each of the regions. Also, we derived from the force generated in the permanent magnet surface using the Maxwell stress tensor. The analytical results are proved the validity by comparing to the finite element method (FEM).

• 한국전산유체공학회:학술대회논문집
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• 1996.05a
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• pp.125-130
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• 1996

A numerical analysis is conducted on heat transfer and fluid flow of a plasma spraying process under the DC-RE hybrid electromagnetic field. Plasma flow is analyzed by using Eulerian approach and the equation of particle motion is simultaneously solved using a trajectory analysis with a lumped-heat-capacity model. Axisymmetric two dimensional electromagnetic fields governed by Maxwell's equations are solved based on a vector potential concept. The effects of the RF electromagnetic field on the temperature and velocity fields of the turbulent plasma flow are clarified. Control characteristics of phase changes and dispersed features of particles by applying the RF electromagnetic field are also clarified in an attempt to improve the plasma spraying process

• Journal of the Korean Electrochemical Society
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• v.9 no.4
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• pp.151-157
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• 2006

A two-dimensional numerical model to study the performance of anode-supported flat-tube solid oxide fuel cell (SOFC) far the cross section of the cell in the flow direction of the fuel and air flows is developed. In this model a mass and charge balance, Maxwell-Stefan equation as well as the momentum equation by using, Darcy's law are applied in differential form. The finite element method using FEMLAB commercial software is used for meshing, discritization and solving the system of coupled differential equations. The current density distribution and fuel consumption as well as water production are analyzed. Experimental data is used to verify a predicted voltage-current density and power density versus current density to judge on the model accuracy.

• Journal of Sensor Science and Technology
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• v.7 no.3
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• pp.203-210
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• 1998

An experimental study of an eddy current nondestructive testing system to measure dimensions of cylindrical metallic rods, such as cross-sectional area or diameter, is presented. Impedance characteristics of a solenoid sensor, which are generally based on Maxwell's equations in electromagnetic field, are briefly discussed for inspecting geometrical parameters of the coil sensor and testing materials. A measurement system for detecting the diameter of the metallic rod is implemented. This instrument has capabilities for detecting the sensor output signals and estimating demensions of the testing material, continuously. As a result, it was shown that the eddy current sensor with an encircling coil could estimate the diameter of metallic rod. The implemented measurement system gives accurate information for inspecting the dimension of conducting rod with good sensitivity.

• Journal of electromagnetic engineering and science
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• v.9 no.1
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• pp.12-16
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• 2009

This paper presents a new iterative locally one-dimensional [mite-difference time-domain(LOD-FDTD) method that has a simpler formula than the original iterative LOD-FDTD formula[l]. There are fewer arithmetic operations than in the original LOD-FDTD scheme. This leads to a reduction of CPU time compared to the original LOD-FDTD method while the new method exhibits the same numerical accuracy as the iterative ADI-FDTD scheme. The number of arithmetic operations shows that the efficiency of this method has been improved approximately 20 % over the original iterative LOD-FDTD method.

• Structural Engineering and Mechanics
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• v.60 no.2
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• pp.271-299
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• 2016

In this article, based on the higher-order shear deformation plate theory, buckling analysis of a rectangular plate made of functionally graded piezoelectric materials and its effective parameters are investigated. Assuming the transverse distribution of electric potential to be a combination of a parabolic and a linear function of thickness coordinate, the equilibrium equations for the buckling analysis of an FGP rectangular plate are established. In addition to the Maxwell equation, all boundary conditions including the conditions on the top and bottom surfaces of the plate for closed and open circuited are satisfied. Considering double sine solution (Navier solution) for displacement field and electric potential, an analytical solution is obtained for full simply supported boundary conditions. The accurate buckling load of FGP plate is presented for both open and closed circuit conditions. It is found that the critical buckling load for open circuit is more than that of closed circuit in all loading conditions. Furthermore, it is observed that the influence of dielectric constants on the critical buckling load is more than those of others.