• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3B
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• pp.244-250
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• 2002

In this paper, rile scattered field from a random rough perfectly conducting surface by method of moment(MoM) was computed. A one-dimensional random rough surface predetermined statistical properties was generated by a digital computer. The number of surface realization for the computed field and the width of surface realization are set to be 100, 80 λ, respectively. To eliminate the scattering from the ends of the surface, the Gaussian taper function is used. Using Monte Carlo technique, we calculated hi-static scattering and back scattering coefficient. In order to verify the result by MoM we compare the MoM results with those of Kirchhoff approximations, which show good agreement between them.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2A
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• pp.63-69
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• 2003

In this paper, the scattered field from a perfectly conducting fractal surface by Finite-Difference Time-Domain(FDTD) method was computed. A one-dimensional fractal surface was generated by using the fractional Brownian motion model. Back scattering coefficients are calculated with different values of the spectral parameter(S0), fractal dimension(D) which determine characteristics of the fractal surface. The number of surface realization for the computed field, the point number, and the width of surface realization are set to be 80, 1024, 16λ, respectively. In order to verify the computed results these results are compared with those of small perturbation methods, which show good agreement between them.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2A
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• pp.70-79
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• 2003

A theoretical presentation of evanescent coupling is offered with respect to the refractive indexes between a side polished optical fiber and an infinitely planar waveguide with a conductor cladding(PWGCC). The PWG is suspended at a constant distance from an unclad fiber core and attached with the perfect conductor(PEC) on one side. The behavior of the distributed coupler is examined using a coupled mode model, which takes account of the two dimensions of the waveguide configuration. The coupling and propagation of light were found to depend on both the relationship between the refractive index values of each structure and the configuration of the side polished fiber used in the PWGCC. The spreading of light in the unconfined direction of the PWGCC is described in terms of a simple geometrical interpretation of the synchromization condition that is in agreement with a previous investigation of the problem based on the coupled-mode theory(CMT). The power of the light propagation in the fiber decreased exponentially along the fiber axis as it was transferred to the PWGCC.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.153-158
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• 2016

In this paper, TE(transverse electric) scattering problems by a conductive strip grating between grounded double dielectric layer are analyzed by applying the PMM(point matching method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the conductive boundary condition is applied to analysis of the conductive strip. The numerical results for normalized reflected power are analyzed by according as the width and spacing of conductive strip, the relative permittivity and thickness of the double dielectric layers, and incident angles. The most normalized reflected powers of the sharp variations in minimum values are scattered in direction of the other angles except incident angle. The numerical results for the presented structure of this paper having a grounded double dielectric layer are shown in good agreement compared to those of the existing papers.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.65-70
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• 2015

In this paper, the solutions of TE (transverse electric) scattering problems by a conductive strip grating over grounded two dielectric layers are analyzed by applying the PMM (point matching method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the conductive boundary condition apply to analysis of conducting strip. The most normalized reflected powers of the sharp variations in minimum values are scattered in direction of the other angles except incident angle. The numerical results for normalized reflected power are analyzed by according as the width and spacing of conductive strip, the relative permittivity and thickness of the two dielectric layers, and incident angles. The numerical results of present numericl analysis are shown in good agreement compared to those of the existing papers using FGMM (fourier galerkin moment method).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.87-92
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• 2016

In this paper, the solutions of TE(transverse electric) scattering problems by a conductive strip grating over two dielectric layers are analyzed by applying the PMM(point matching method) known as a numerical method of electromagnetic field. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the conductive boundary condition apply to analysis of conducting strip. The most normalized reflected and transmitted powers having a sharp variations are scattered in direction of the other angles except incident angle. The numerical results for the normalized reflected and transmitted powers are analyzed by according as the width and spacing of conductive strip, incident angles, and the relative permittivity and thickness of the two dielectric layers. To confirm the validity of this paper, the numerical results of presented structure are shown in good agreement compared to those of the existing papers.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.83-88
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• 2017

In this paper, TE(transverse electric) scattering problems by a conductive strip grating between a double dielectric layer are analyzed by applying the PMM(point matching method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the conductive boundary condition is applied to analysis of the conductive strip. The numerical results for the normalized reflected and transmitted power are analyzed by according as the width and spacing of conductive strip, the relative permittivity and thickness of the double dielectric layers, and incident angles. The most normalized reflected powers of the sharp variations in minimum values are scattered in direction of the other angles except incident angle. The numerical results for the presented structure of this paper are shown in good agreement compared to those of the existing papers.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.29-33
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• 1990

Efficient numerical method is developed for treating electromagnetic problems of scattering and radiation from surfaces. Special consideration is given to the treatment of edges so that rather arbitrary geometrical configurations may be handled. For the conducting body problems considered, an electric field integral formulation is used, and the method of moments is applied using pulse expantions to present currents. Numerial results indicate that the approach is free os anomalies in the behavior of current for body of revoution.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.184-187
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• 1987

The method of Conjugate Gradient(C.G.M) is applied to the solution of current distribution from body of revolution (B.O.R).Using the C.G.M it is possible to analyze electrically large arbtrarily oriented B.O.R. The fundamental differences between C.G.M and moment method are outlined. This method converges for any initial guess and this techniqe gurantees a monotonic convergence. Numerical results are presented for electromagnetic case which show good agreement with moment solution.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.2
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• pp.130-138
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• 1988

The method of conjugate gradient (C.G.M.) is applied to the solution of current distribution from body of revolution(B.O.R.). Using the C.G.M., it is possible to analyze electrically large arbitratily oriented B.O.R.. The fundamental differencess between C.G.M. and moment are outlined. This method converge for any initial guess, and this techniqe guarantees a monotonic convegence. Numerical resulsts are presented for electromagnetic case which shows good agreements with moment solution.