• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.721-726
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• 2023

In this paper, TM electromagnetic scattering problems for conductive strip grating between grounded double dielectric layers are analyzed by applying the FGMM(fourier galerkin moment method) and PMM(point matching method) known as a numerical method of electromagnetic field. The boundary conditions are applied to obtain the unknown field coefficients. In order to deal with the problem of grounded double dielectric layers, numerical calculation was performed only when the thickness and relative permittivity of the dielectric layers had the same value. As the thickness of the dielectric layer and the relative permittivity increased, the overall reflected power increased, and the minimum values of the reflected power shifted in the direction of increasing the strip width. The numerical results obtained by applying the numerical methods of FGMM and PMM to the structure proposed in this paper agree very well.

• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.4
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• pp.21-26
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• 2019

In this paper, TE(transverse electric) scattering problems by a resistive strip grating between a double dielectric layer are analyzed by using 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 resistive boundary condition is applied to analysis of the resistive strip. The numerical results for the normalized reflected and transmitted power are analyzed by according as the width and spacing of resistive strip, the relative permittivity and thickness of the double dielectric layers, incident angles, and uniform resisitivity. Typically, the reflected power for the conductive strip increased as the value of the relative dielectric constant increased, the reflected power for the resistive strip with uniform resistivity decreased as the value of the resisvivity increased. The numerical results for the presented structure of this paper 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.19 no.2
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• pp.47-52
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• 2019

In this paper, TE(transverse electric) scattering problems by a conductive strip grating between a double dielectric layer are analyzed by applying the FGMM(Fourier-Galerkin moment method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, 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. Generally, as the value of the dielectric constant increases, the reflected power increases and the transmitted power decreases, respectively. As the dielectric constant increases, the current density induced in the strip increases as it goes to both strip ends. The numerical results for the presented structure of this paper 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.22 no.1
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• pp.29-34
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• 2022

In this paper, thr H-polarized scattering problems by a resistive strip grating in a 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 resistive boundary condition is applied to analysis of the resistive strip. The %error of the convergence of the reflected power according to the relative permittivity of the dielectric layer and the size of the number of rows in the square matrix was compared, as the size of the number of rows in the square matrix increased, the accuracy of the reflected power increased. As the resistivity of the resistive strip decreased, the thickness of the dielectric layers decreased, and the relative permittivity of the dielectric layers increased, the reflected power increased. 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 Convergence on Culture Technology
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• v.9 no.3
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• pp.619-624
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• 2023

In this paper, TE(transverse electric) scattering problems by a resistive strip grating between a double dielectric layer are analyzed by using the FGMM(fourier galerkin moment 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 resistive boundary condition is applied to analysis of the resistive strip. In order to deal with the problem of the double dielectric layer, numerical calculation was performed only when the thickness and relative permittivity of the dielectric layers had the same value. Overall, as the resistivity of the uniform resistivity increased, the current density induced in the resistive strip decreased, the reflected power decreased, and the transmitted power relatively increased. The numerical results of the structure proposed in this paper are shown in good agreement compared to the results of PMM, a numerical analysis method of the existing paper.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.363-366
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• 1998

High frequency scattered fields by a double impedence wedge are computed. In the procedure of the computation, arbitrary impedence faces and wedge angles are considered. The diffraction coefficients for the single, double and triple diffraction mechanism are founded. The second-order and third-order diffracted fields are approximated via the extended spectral ray method and the modified Pauli-Clemmow method of the steepest descent. The maliuzhinets function which is very difficult to obtain accurate value is approximated by the Volakis's asymtotic expression. Numerical computations are performed for the various wedge angles and surface impedence values.

• Journal of Radiation Protection and Research
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• v.35 no.2
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• pp.69-76
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• 2010

Prototype double-scattering Compton camera, which consists of three gamma-ray detectors, that is, two double-sided silicon strip detectors (DSSDs) as scatterer detectors and a NaI(Tl) scintillation detector as an absorber detector, could provide high imaging resolution with a compact system. In the present study, the energy resolution and the timing resolution of component detectors were measured, and the parameters affecting the energy resolution of the DSSD were examined in terms of equivalent noise charge (ENC). The energy resolutions of the DSSD-1 and DSSD-2 were, in average, $25.2keV{\pm}0.8keV$ FWHM and $31.8keV{\pm}4.6keV$ FWHM at the 59.5 keV peak of $^{241}Am$, respectively. The timing resolutions of the DSSD and NaI(Tl) scintillation detector were 57.25 ns FWHM and 7.98 ns FWHM, respectively. In addition, the Compton image was obtained for a point-like $^{137}Cs$ gamma source with double-scattering Compton camera. From the present experiment, the imaging resolution of 8.4 mm FWHM (angular resolution of $8.1^{\circ}$ FWHM), and the imaging sensitivity of $1.5{\times}10^{-7}$ (intrinsic efficiency of $1.9{\times}10^{-6}$) were obtained.

• Current Optics and Photonics
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• v.1 no.3
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• pp.228-232
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• 2017

We propose a reflector-type perfect absorber with double absorption lines using electric and magnetic dipoles of Mie resonances in an array of silicon nanospheres on a silver substrate. In the visible range, hundreds of nanometer-sized nanospheres show strong absorption lines up to 99%, which are enhanced by the interference between Mie scattering and reflections from the silver substrate. The air gap distance between the silicon particles and silver substrate controls this interference, and the absorption wavelengths can be controlled by adjusting the diameter of the silicon particles over the entire range of visible wavelengths. Additionally, our structure has a filling factor of 0.322 when the absorbance is nearly 100%.

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.1006-1010
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• 1997

The nature and analysis methods of complicated decay profiles found in forced Rayleigh scattering (FRS) have been investigated for the probe diffusion of methyl yellow in 2-propanol. The complementary shifted and ground state grating effect, which is known to be the origin of non-single exponential decays, was analyzed by non-linear regression fitting to a double exponential model function. We confirmed that the parameters were highly correlated so that it was difficult to extract a unique set of parameters in the presence of experimental noise. Nevertheless, a reasonable range of decay time constants could be estimated from the grating spacing dependence.