• 센서학회지
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• 제12권5호
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• pp.199-204
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• 2003

본 논문에서는 Ta-N 스트레인게이지를 이용한 극한 환경용 세라믹 박막형 압력센서의 제작 및 특성에 관하여 연구하였다. 압력감지부로 Ta-N 스트레인게이지를 사용하였으며, SDB(Si-wafer Direct Bonding)와 전기화학적 식각정지법을 이용하여 매몰 cavity를 가지는 저가격 고수율의 Si 박막 다이어프램을 제작하였다. 또한, 실리콘 박막 다이어프램상에 박막형 스트레인게이지를 형성하여 세라믹 박막형 압력센서를 제작하였다. 제작된 세라믹 박막형 압력 센서는 기존의 스트레인 게이지를 이용한 로드셀에 비해서 온도특성이 우수하고 재현성, 소형화, 집적화 및 저가격화가 가능하기 때문에 고온, 고압 등의 각한 환경에서도 사용이 가능할 것으로 기대된다.

• 한국지진공학회논문집
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• 제8권2호
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• pp.83-93
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• 2004

본 연구에서는 지하구조물의 내진 설계를 위한 수정된 응답변위법을 제안하였다. 먼저 기존 응답변위법의 적용성을 검증하기 위해서 매설심도와 지반조건을 변수로 하여 국내의 특성이 반영된 경우에 대한 해석을 수행하였으며 정밀 동적 해석의 결과와 비교하였다. 최대휨모멘트 및 상대 변위를 비교한 결과, 응답변위법의 정확도에 영향을 크게 미지는 속도응답스펙트럼과 지반반력계수 산정의 필요성이 확인되었다. 따라서 국내의 실정에 맞도록 수정된 속도응답스펙트럼과 새로운 지반반력계수 산정식 제안을 위한 방법을 고찰하였다. 제안된 응답변위법의 타당성 및 적용성을 검증하기 위하여, 지반의 조건 및 구조물의 크기 매설심도, 기반암의 위치를 변화시키면서 해석을 수행하였다. 응답변위법의 해석결과와 정밀 동적 해석법의 결과를 비교ㆍ분석하여 국내 지하구조물의 내진 설계를 위한 응답변위법의 적용 가능성을 검증하였다.

• The Journal of the Acoustical Society of Korea
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• 제23권1E호
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• pp.31-39
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• 2004

Backscattered underwater signals from multiple scatterers contain information regarding resolvable spatial distribution of scatterers. This experimental study describes the spectral characteristics of backscattered signal from multiple scatterers, which are regularly or randomly spaced, in terms of their amplitude and phase and a proper signal analysis that will eventually provide scatterer spacing estimation. Air-filled tubes suspended in water, steel balls and plastic tubes buried in the sediment are the multiple scatterers. The cepstrum and the spectral autocorrelation (SAC) methods were used to estimate the scatterer spacing from the backscattered signals. It was found that the SAC method could be improved by employing singular value decomposition (SVD) to extract the effective rank for the spectral components. Unlike the conventional method of estimating the density of scatterers within the insonified volume of water, this type of estimation method would provide better understanding of the spatial distribution of scatterers in the ocean.

• 한국안전학회지
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• 제30권2호
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• pp.9-13
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• 2015

This paper describes the analysis of deterioration characteristics for connection factor used in grounding system. The connection method of grounding system is specified in IEC standard. In order to analyze the deterioration characteristics for connection factor, deterioration test was carried out when the connection factor was buried in salt water and underground. The test connection factors were C-type sleeve, clamp, and exothermic welding. As a consequence, most of the connection factor was corroded, and the electrical resistance decreased after deterioration. The analytical results can be used to establish the safety of grounding system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.2126-2127
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• 2011

This paper describes the analysis of deterioration characteristics for connection factor according to connection method of grounding system. The connection method of grounding system is specified in IEC standard. In order to analyze the deterioration characteristics for connection factor, deterioration test was carried out when the connection factor was buried in salt water and underground. The test connection factors were C-type sleeve, clamp, and exothermic welding. As a consequence, most of the connection factor was corroded, and the electrical resistance decreased after deterioration. The analytical results can be used to establish the safety of grounding system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.828-831
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• 2001

A simple and versatile method of manufacturing semiconductor devices with pn-junctions used the silicon direct bonding technology with simultaneous impurity diffusion is suggested . Formation of p- or n- type layers was tried during the bonding procedure by attaching two wafers in the aqueous solutions of Al(NO$_3$)$_3$, Ga(NO$_3$)$_3$, HBO$_3$, or H$_3$PO$_4$. An essential improvement of bonding interface structural quality was detected and a model for the explanation is suggested. Diode, Dynistor, and BGGTO structures were fabricated and examined. Their switching characteristics are presented.

• 한국결정학회지
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• 제12권1호
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• pp.20-24
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• 2001

NiZn-ferrite was synthesized usign waste iron oxide catalysts which were produced from styrene monomer process and buried underground as an industrial wastes. The spinel type ferrite was obtained by calcination and sintering of the mixture of finely ground waste catalysts, nickel oxide and zinc oxide powders. The sintered body of Ni/sub 0.5/Zn/sub 0.5/Fe₂O₄ composition at 1230℃ for 5 hours showed the density of 5.38g/㎤, and initial permeability of 59 at 1 kHz. Not only cerium oxide, which existed as a major component in the catalyst, but also unicorporated NiO and ZnO into spinel structure remained as second phases after sintering.

• 복식
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• 제53권4호
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• pp.177-186
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• 2003

This study is based on the observation of clothes excavated from of YeoHung Min( 1586∼1656)'s grave, which enable to understand of woman's funeral clothes among upper class in mid 17C. Lady Min buried with her husband Jung (Clan of Dong Rae)'s grave where located in KwanAk gu, Seoul was move out another place in 1989. During excavation of the grave, 31 pieces form 5 different type of clothes and total 18 pieces form 8 different from Lady Min (Clan of YeoHung). Remarkable finding from the excavated clothes is the Nuwooli(veil) which is known to be discovered first time in Korea, and a piece of tooth, which is related with funeral custom of those day, and cotton seeds are found from chima(skirt) and Jogori(jacket). Jangot(coat) has been used for the use of over garment assuming the changes of Jogori form during mid of Josun dynasty. It is also remarkable that padded and quilted clothing is still being commonly used until mid-l7C.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.326-329
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• 1999

In this paper, we demonstrate a polarization independent optical phase modulator using electro-optic polymer, P2ANS. To overcome the intrinsic polarization dependency of electro-optic effect, we control the optic axis using a new electrode structure. P2ANS(42:75) and P2ANS(25:75) are used for the core layer and the cladding layer, respectively. The buried-type single mode waveguide is fabricated by oxygen ion reactive etching and electic poling is performed by applying 1, 200V at 135$^{\circ}C$. The measured V$_{\pi}$ of the device for both TE and TM modes are 70V.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 Proceedings of 5th International Joint Symposium on Microeletronics and Packaging
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• pp.69-72
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• 2000

기판과의 동시소성에 의한 고주파 MCM-C(Multi-Chip-Module-Cofired)용 저항을 제작하고 6 GHz 까지의 RF 특성을 측정하였다. 기판은 저온 소성용 기판으로서 총 8층으로 구성하였으며, 7층에 저항체 및 전극을 인쇄하고 Via를 통하여 기판의 최상부까지 연결되도록 하였다 저항체 Pastes, 저항체의 크기, Via의 길이 변화에 따라서 저항의 RF 특성은 고주파일수록 더욱 DC 저항값에서부터 변화되는 양상을 보였다. 내부저항의 등가회로를 구현한 결과, 저항은 전송선로, Capacitance 성분이 혼재되어 있는 것으로 나타났으며 전극의 형태에 따라 Capacitance 성분이 많은 차이를 나타내었다.