• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.113-116
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• 2000

평행평판의 원면에 위치한 슬릿을 통하여, 슬릿의 바로 윗 부분에 도체 스트립이 있을 때 일어나는 전자기적 결합 현상에 대하여 살펴보았다. 슬릿의 폭이 파장에 비하여 매우 작을 때와 매우 클 때의 두 경우로 나누어서 기술하였다. 슬릿의 폭이 좁은 경우는 기존의 개구결합(aperture-coupled) 마이크로스트립 안테나에 해당되며 슬릿의 폭이 넓은 경우는 기존의 proximity-coupled 마이르로스트립 안테나에 해당된다. 본 연구의 결과는 기존의 마이크로스트립 안테나의 급전구조와 기존의 마이크로스트립 누설파 안테나의 급전구조 설계에 도움을 줄 것으로 생각된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.10
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• pp.1094-1102
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• 2010

In this paper, the problem of electromagnetic transmission via slits in a cavity inside conducting screen of finite thickness is considered for the case that the TE(to the slit axis) polarized plane wave is incident on the slit in conducting screen. Using the method of moments the variations of the transmitted power through the slits are obtained and compared with those computed from an equivalent circuit constructed using an equivalent slit admittance. It is found that the effective slit width of a narrow slit, at resonance, becomes $1/{\pi}$ wavelengths independently of the actual slit width. The transmission resonance phenomena in the proposed geometry are explained in connection with the variations of an equivalent admittance of the slit in the cavity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.832-836
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• 2008

In this study, the electromagnetic coupling problem through narrow slit in an infinite conducting screen is considered for the case that the TM polarized plane wave is incident upon the slit. This study aims at explaining the mechanism of the maximum power transmission via the resonated slit using the equivalent circuit. It is shown that the transmitted power through the slit for the case of resonance corresponds to the power normally incident upon the conducting plane of the effective width 1/pi wavelengths, irrespective of the slit width. Some similarities between the maximum power transmissions observed in both the proposed structure and narrow slit in thick conducting screen are described from the viewpoint of equivalent circuit. In addition, it is found that, when the slit is resonated, the transmitted power equal to the scattered power.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.100-101
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• 2002

He-Ne 레이저를 머리카락에 조사시키면 스크린에 단일 슬릿에 의한 회절무늬와 같은 형태의 무늬가 나타난다. 그래서 일반적으로 머리카락 슬릿에 의한 회절무늬를 단일 슬릿에 의한 회절무늬로 기술하는 경향이 있다. 그러나 단일 슬릿에 의한 회절무늬와 머리카락 슬릿에 의한 회절무늬를 비교해 보면 아래 사진에 나타난 것 같이 단일 슬릿에서는 중앙의 제 1 극대점이 밝은 선으로 되어 있지만 머리카락 슬릿에서는 중앙에 밝은 spot이 나타나는 것을 관찰할 수 있다. 따라서 본 연구에서는 이 중앙의 spot무늬가 왜 발생하는지 그 원리를 이론적으로 규명하고 실험하는데 목적이 있다. (중략)

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.11
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• pp.1116-1122
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• 2004

The problem of electromagnetic coupling through a slit in a flanged parallel-plate waveguide is considered. The equivalent slit admittance associated with reactive powers near the coupling slit inside and outside the waveguide has been obtained. The maximum coupling mechanism for the case of narrow slit has been quantitatively discussed. The effects of various geometrical parameters such as guide height, slit width, and slit of offset on the radiation characteristics of the geometry have been investigated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2059-2065
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• 2009

In this study, it has been considered that the TEM wave is incident on the transverse slit in the upper plate of a short-ended parallel-plate waveguide (PPW). An equivalent slit admittance and complex power for the case of narrow slit are obtained. The conditions for the slit voltage and the complex power in case of the maximum coupling through the slit with a nearby scatterer exterior the PPW are checked.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.3
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• pp.143-150
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• 2003

Based on the eigenfunction expansion method, the interaction between monochromatic waves and a partially immersed slotted plate with a back wall has been investigated. Analytical results show that the reflection coefficients by a partially immersed slotted plate depend on the porosity, immersed depth, chamber width, incidence angle and wave frequency. It is found that the reflection coefficient has minimum value within entire frequency range when the porosity has optimal value 0.1. Comparison between the analytical results and the experimental results(Zhu,2001) of reflection coefficients is made for various chamber widths, immersed depths and wave periods with good agreement. The present analytic method can account adequately for energy dissipation caused by flow separation behind a slotted plate and provide the design informations for the construction of slit caisson breakwater.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.1
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• pp.83-90
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• 2009

In this paper, the problem of electromagnetic transmission through slits in two parallel conducting plates which separate two half spaces is considered. The coupled integral equations for the electric field distributions over the slits are developed for the case that the TM polarized plane wave is incident on the slit and solved by the method of moments. The transmitted power beyond the slit-perforated conducting parallel plates is computed in order to check the variations of the coupled power through slits against some parameters such as the incident angle of the TM polarized wave, slit width, lateral distance between two slits, and distance between the conducting plates. When the lateral distance between two slits approaches near the multiples of half wavelengths, the transmission resonance (maximum power transmission) is observed. If the slit width in the incident side is narrow and the distance between conducting plates is small compared to the wavelength, the maximum of transmitted power is observed to be nearly independent of the incident angle and slit width. In addition, the mechanism of the transmission resonance in the present geometry is explained using a simplified geometry and its equivalent circuit.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.2
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• pp.111-118
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• 2017

In this paper, combustion tests were performed to investigate performance characteristics of a canted slit-type pintle injector engine which uses kerosene and liquid oxygen as propellants. The number of slits, slit angle and blockage factor were chosen as design variables of the pintle injector. ${\Delta}SR$ was newly defined as the difference of skip ratio caused by both sides of the tip of the canted slit. The experimental results showed that optimal combustion was performed when the blockage factor is about 1 and the difference is less than 0.26.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.108.2-108.2
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• 2010

최근 지역어민 또는 관광객들이 친수공간으로 이용할 수 있는 경사식 상부공의 시공이 많아지고 있다. 경사식 상부공은 수평파력을 저감하는 동시에 사면벽에 작용하는 파력을 제체의 안정에 이용할 수 있다. 그러나 직립식 상부공과 비교하여 전달파고가 커지는 문제점을 가지고 있다. 본 연구에서는 상부공에 슬릿을 주어 슬릿 유무에 따른 파력 감소에 대한 수치모의를 실시하였다. 수치모의에는 범용성이 높은 단면 2차원 해석모델인 수치파동수로(CADMAS-SURF)를 사용하였고, 입사파랑으로는 규칙파를 조파하였으며, 전면불투과벽, 슬릿부, 유수실 바닥, 유수실 후벽에서 파력을 측정하였다. 수치모의 결과 상부공에 슬릿이 있는 경우 뚜렷한 파력 감소 효과를 보였으며, 파력감소 효과로 인하여 케이슨의 중량을 줄일 수 있어 공사비 절감 효과도 기대할 수 있었다.