• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.1
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• pp.10-16
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• 1995

The E-polarized scattering problems by a perfect conductor strip grating are analyzed by the method of moments. For an E-polarization the induced surface current density is expected to blow up at the strip both edges. Then the induced surface current density on the strip is expanded in a series of multiplication of Ultraspherical ploynomials with zeroth order and functions with appropriate edge boundary condition. The numerical results for current density and reflection cofficient are compared with other functions, it is shown that numerical results better improves the convergence of the moment method soulutions with general incident angles than the existing several other functions. The sharp variation points in the magnitude of geometric-optical reflection coefficient can be moved by varying the incident angle, strip width, and strip spacing.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.11
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• pp.57-61
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• 1992

In this paper, the shielding characteristics of a cylindrical multilayered dielectric are analyzed. In order to evaluate shielding effects, we consider the case that plane waves are incident upon an infinitely long cylindrical multilayered dielectric which surrounds a conductor core. For perfect and lossy dielectric distributions, total induced currents at the conductor surface are computed. It was found from those results that electromagnetic characteristics of the multilayered dielectric are largely dependent on dielectric distribution.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.160-165
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• 2006

We have designed a high-transmission nano aperture in a perfect electric conductor film with the incident beam of 532 nm wavelength. The aperture basically has a C-shape and is known to produce a bright spot nearby the aperture in small size less than diffraction limit. The bright spot is strongly coupled with the local plasmon excited through the aperture hole. The characteristics of transmission and peak power of the aperture output were calculated using finite differential time domain (FDTD) technique, and the geometry of the aperture was determined to get a maximum transmission and peak power. To find the effect of the surface plasmon induced near by the aperture, we calculated the variations of the transmittance and the beam sizes by changing the size of the input beam irradiated on the aperture.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.754-762
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• 2003

The coupled and propagated property of the composite side-polished fiber and infinite planar waveguide with conductor cladding (PWGCC) is presented by using the 3-D finite difference beam propagating method (FD-BPM) in according to the variety of refractive indexes between the fiber and the infinite planar waveguide. It is also introduced for the technique to be applied at and consisted of the analysis domain of 3-D FD-BPM for the coupling between the side-polished fiber and PWG. It is also compared the properties of coupling between the side-polished fiber and PWGCC with them of the general symmetric and asymmetric PWG without perfect conductor (PEC), which has been investigated by many researcher.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.54-58
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• 2006

This paper deals with primary consideration in down-conductor system and earth-termination system design of apartments. For down-conductor system, steelworks within reinforced concrete apartment structures have the electrical continuity, however, lashing is not suitable for lightning-current-carrying connections. So this paper suggest that the additional dedicated conductors should be installed and they are should be lashed to the reinforcement steel. Also this paper suggested the foundation earth electrode and global earth system as the earth-termination system of the apartments. But perfect bonding system is essential in lightning protection system to avoid life hazard and to protect electronic equipments.

• Journal of the Optical Society of Korea
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• v.7 no.1
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• pp.20-27
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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 couple. 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 synchronization 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, where it was carried away.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.2
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• pp.146-152
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• 2008

The frequency of lightning is increased due to improbable weather condition and global wanning. This phenomenon increases economical damage as well as human damage. Advanced countries like europe and north america have applied the facility standard of lightning by accumulating a store of quantitative data about lightning research. Lightning facility is composed of the lightning accepting part for induction lightning, ground connected electrode which conducts lightning current. The lightning accepting part is composed of normal rod, horizontal conductor, ESE lightning rod. Moreover, lightning accepting part is taken to use by the method of protection. This paper suggests HEC(Hybrid ESE-Conductor) method which mixes horizontal conductor and ESE lightning rod. This is also discovered by experiment that the starting point of corona discharge current is low, so it is efficient for lightning protection comparing with other methods. Moreover, distribution of electric field is analyzed qualitatively by finite element method. It also results in the relation of the starting point of corona discharge current. Corona discharge current makes minute current about some ${\mu}A$ between the electrodes by the strength of electric field. Also it occurs insulation destruction of gas, and it is developed to the shape of streamer by increase of the strength of electric field. We can find that the initial occurrence of streamer and contact probability of lightning can have advantage after researching the starting point of corona discharge current and discharge current of lightning striking point. This research demonstrates that the suggested HEC method is economically competitive as a lightning protection facility, and it takes a capably perfect role.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.211-214
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• 1999

Periodical surfaces with the sawtooth profile are studied on their backscattering by the TE plane wave incident. The backscattering is calculated by the mode-matching method. The surfaces are perfect conductor and are covered with dielectric materials to make a flat surface. It is observed that a cover filled with multiple dielectric layers can be used to reduce the backscattering at an arbitrary incident angle.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.1-7
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• 1997

The physical optical solution to the E-polarized diffraction by a composite wedge consisting of perfect conductor and lossless dielectric cannot sayisfy not only the boundary conditions at the wedge interfaces but also the edge condition at the wedge tip. Its diffraction coefficients are extended outside the composite wedge to become the exact solution to the perfectly conducting wedge as its relative dielectric constant increases to infinite or decreases to 1. It is assured that the extended diffraction coefficients approach zero in the arificially complementary region of the composite wedge.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.869-875
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• 2015

In this paper, the surface wave that caused the isolation problem when the design of the array antenna is studied. The grounded dielectric slab model is used in order to simulate in the similar environment with the surface wave of the microstrip patch antenna. The propagation of the surface wave on the various types of grounds which are defected ground structure(DGS), perfect magnetic conductor(PMC), Soft-surface, and Hard-surface is simulated. As a result, 25 % power is blocked by the DGS when the TM-wave incident. Also, 95 % power is blocked by the PMC and Soft-surface. This study will be very useful to increase the gain of an array antenna by improving the isolation between the antenna elements.