• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2017년도 춘계학술대회 논문집
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• pp.97-97
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• 2017

This study investigated the corrosion protection by electrodeposited copper layer on AZ31 Mg alloy with and without additional silver layer by immersion test, salt spray test, OCP transient and potentiodynamic polarization experiment. The single electrodeposited Cu layer on AZ31 Mg alloy showed a nodular structure with many imperfections of crevices between the nodules, which resulted in the fast initiation of pitting corrosion within first few hours of immersion. Double-layer coating of Cu and outer Ag layer slightly increased the initiation time for pitting corrosion. Triple-layer coatings of Cu/Ag/Cu exhibited the most efficient corrosion protection of AZ31 Mg alloy, compared to the single- and double-layer coatings. Surface morphology of the outer Cu layer in the triple-layer was changed from the nodular structure to fine particle structure with no crevices due to the presence of an additional Ag layer. Thus, the improved corrosion resistance of AZ31 Mg alloy by electrodeposited Cu/Ag or Cu/Ag/Cu layers is readily ascribed to the decreased number of imperfections in the electrodeposited layers due to the additional silver layer. It is concluded that the additional silver layer provides many nucleation sites for the second Cu plating, resulting in the formation of finer and denser structure than the first Cu electrodeposit.

• 산업공학
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• 제23권1호
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• pp.68-77
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• 2010

Digital reactor protection system which consists of many identical modules, is fault- tolerant to provide high safety. The modules themselves including DSP(digital signal processing) card are also fault-tolerant in nature. This paper assesses the safety for being-designed digital reactor protection system of 2-out-of-4 G structure with lockout. Some interesting design alternatives are compared. Fault tree analysis for assessing system safety is performed by Relex software. The selected reactor protection system fully satisfies EPRIURD stipulation of mean failure time of 50 years.

• 전기전자학회논문지
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• 제26권1호
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• pp.119-123
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• 2022

본 논문은 추가 기생 바이폴라 BJT로 인해 높은 홀딩전압을 갖는 ESD 보호소자에 Self-Biasing 구조를 추가하여 12V 급 어플리케이션에 적합한 새로운 ESD 보호소자를 제안한다. 제안된 소자의 동작원리와 전기적 특성 검증을 위해 Synopsys사의 TCAD Simulation을 사용하여 current density simulation과 HBM simulation을 수행하였고 추가된 Self-Biasing 구조 동작을 확인하였다. Simulation 결과 제안된 ESD 보호소자는 기존의 ESD 보호소자와 비교하여 높은 수준의 홀딩전압을 갖는 것을 확인하였고 이는 듀얼구조로 인한 높은 면적효율과 12V급 어플리케이션에서 충분한 래치업 면역 특성을 가질 것으로 기대된다.

• 한국위성정보통신학회논문지
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• 제11권4호
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• pp.21-26
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• 2016

PPS 소자가 삽입된 N형 실리콘 제어 정류기(NSCR_PPS) 소자에서 채널차단영역의 이온주입 변화가 정전기 보호 성능에 미치는 영향을 연구하였다. 종래의 NSCR 표준소자는 on 저항, 스냅백 홀딩 전압 및 열적 브레이크다운 전압이 너무 낮아 마이크로칩의 정전기보호소자로 적용이 어려웠다. 그러나 본 연구에서 제안하는 채널 차단 영역의 이온주입 조건을 변화시켜 각각 변형설계된 소자에서는 채널 차단 이온주입이 정전기 보호성능의 향상에 영향을 주는 중요한 파라미터였으며, CPS_PDr+HNF 구조의 변형소자는 정전기보호소자의 설계창을 만족시키는 향상된 정전기보호성능을 나타내어 고전압 동작용 마이크로 칩의 정전기보호 소자로 적용 가능함을 확인하였다.

• Journal of Astronomy and Space Sciences
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• 제1권1호
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• pp.35-39
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• 1984

Space Shuttle의 성공적인 비행을 가능케한 요인중의 하나가 Silica Tile을 사용한 재사용 할 수 있는 Thermal Protection System의 설계이었다. 이러한 Thermal Protection System의 기본 설계 개념을 밝히고 또한 Silica Tile의 생산 공정과 Tile System의 구조를 서술하였다.

• 방재기술
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• 통권52호
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• pp.12-18
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• 2012

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1992년도 가을 학술발표회 논문집
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• pp.148-155
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• 1992

A method to verify seismic qualification of the plant protection system cabinet for a nuclear power plant is presented. A finite element model of the cabinet is developed and correlated to the dynamic properties observed during in-situ vibration test of the actual structure. The results of the modal analysis provide insight into the fundamental dynamic properties of the structure. Techniques for verifying structural integrity and operability are exemplified by summarizing response spectrum and time history analyses of the structure.

• 전기전자학회논문지
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• 제21권3호
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• pp.234-239
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• 2017

본 논문에서는 PMOS 구조를 삽입한 새로운 구조의 SCR(Silicon Controlled Rectifier)기반 ESD(Electrostatic Discharge) 보호소자를 제안한다. 제안된 ESD 보호회로는 내부에 PMOS가 추가적으로 형성된 구조적 특징을 지니며, Latch-up 면역 특성과 향상된 감내특성을 갖는다. TCAD 시뮬레이션을 이용하여 기존의 ESD 보호회로와 특성을 비교 분석하였다. 시뮬레이션 분석 결과, 제안된 보호 ESD 보호회로는 기존 SCR 기반 ESD 보호소자 HHVSCR(High Holding Voltage SCR)과 같은 우수한 Latch-up 면역 특성을 지닌다. 또한 HBM(Human Body Model) 최대온도 테스트 결과에 따르면, 제안된 ESD 보호회로는 355K의 최대온도 수치를 가지며, 이는 기존 HHVSCR의 373K와 비교하여 대략 20K가량 낮은 온도특성으로, 더욱 향상된 감내특성을 갖는 것으로 확인되었다. 제안된 ESD 보호소자는 N-STACK 기술을 적용하여 설계하여 전압별 적용이 가능함을 시뮬레이션을 통하여 검증하였다. 시뮬레이터로 시뮬레이션을 해본 결과, 제안된 ESD 보호회로는 단일 구조에서 2.5V의 홀딩전압 특성을 지니며, N배수의 증배에 따라 2-STACK 4.2V, 3-STACK 6.3V, 4-STACK 9.1V로 증가된 홀딩전압을 갖는 것을 확인하였다.

• 한국군사과학기술학회지
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• 제26권3호
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• pp.302-312
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• 2023

This paper describes the analysis of lightning strike zoning, the indirect lightning data simulation and the protection design for lightning indirect effects of equipment by lightning strike for unmanned aircraft consisting of composite wings. Through the analysis of lightning strike zoning according to the external shape of unmanned aerial vehicles, the structure areas that should be protected during lightning strike is derived, and the protection requirements of lightning indirect effects for flight critical equipments and equipment that must be operated upon lightning strike was derived. Lightning protection levels according to the location of mounting equipment and surrounding structure materials for each equipment was derived, and the protection design of the unmanned aerial vehicle with composite structures was also proposed from direct effect of lightning. Later, the lightning protection technology will be verified by the ground test of lightning direct and indirect effects.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.537-542
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• 2001

Recently long-span bridges, such as Kwang-Ahn Grand bridge, Seo-Hae Grand Bridge, Young-Jong Grand Bridge, etc, have been designed and constructed near the shore. It needs to maintain the durability of marine concrete structures which are exposed to severe chloride environments. It is well known that corrosion of reinforcement steels in concrete structure is the most important cause for the durability of concrete structure which can be controlled by systematic preparatory corrosion protection works for economic and safe infrastructures. Various corrosion protection systems have been used for the corrosion protection of reinforcement steels from detrimental chemical components such as chloride, sulphate and etc. Since chloride can be penetrated into concrete in a variety way, an effective method has to be adopted by taking into full economical aspects and technical data of each protection system. The objective of this experimental study is to investigate the corrosion behavior of reinforcing steel in laboratory concrete specimens which are exposed to cyclic wet and dry saltwater, and then to develop pertinent corrosion protection system, such as corrosion inhibitors and cathodic protection for reinforced concrete bridges exposed to chloride environment. Resistance of various corrosion inhibitors and impressed current system have been experimentally evaluated under severe environmental conditions, and thus effective corrosion protection systems could have been Practically developed for future concrete construction.