• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1057-1059
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• 2017

In development of liquid-propellant rocket engine, engine gimbaling requires various types of bellows movements and cryogenic insulation is applied with movement-based design and material on each axial and circular bellows. Cryogenic insulation of Bellows for high pressure line and recirculation line are necessary to maintain cryogenic temperature for engien efficiency and protect from heat transfer and radiation of high temperature components during engine gimbaling.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.313-322
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• 1998

The distributions of chemical oxygen demand (COD) and suspended solid (SS) in Ulsan Bay were simulated and reproduced by a numerical ecosystem model for the practical application to the management of marine water quality and the prediction of water quality change due to coastal developments or the constructions of breakwater and marine facilities. Comparing the computed with the observed data of COD and SS in Ulsan bay the results of simulation were found to be good enough to satisfy the practical applications.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.287-287
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• 2010

휴대용 기기의 사용이 증가하면서 배터리의 고용량화와 소형화가 요구되고 있다. 특히 내시경 캡슐과 같은 의료용 센서 기기에서는 소형화가 매우 중요하며 인체에 해로운 액체전해질이 들어가지 않는 것이 바람직하다. 최근 무선센서, RFID 태그, 스마트 카드 등을 위하여 고체전해질을 사용하는 박막 마이크로 배터리가 개발되고 있으나, 에너지 저장용량이 작아 응용분야가 제한적이다. Si wafer 위에 형성된 고단차의 3차원 구조 위에 박막 배터리를 형성한다면 표면적 증가에 의해 에너지 저장용량 역시 크게 증가할 것이며, Si 기반의 반도체, 디스플레이, 태양전지 등과 쉽게 집적이 가능할 것이다. 본 연구에서는 펄스 레이저 증착법(Pulsed Laser Deposition)으로 리튬 배터리의 cathode 물질인 $LiCoO_2$를 박막으로 제조하고 그 특성을 연구하였다. 펄스 레이저 증착법은 저온 증착이 가능하고 타겟 물질과 같은 조성의 박막을 증착하는 것이 용이한 장점이 있다. Pt, TiN 등의 기판 위에 $LiCoO_2$ 박막을 증착하고 증착 온도와 산소($O_2$) 분압이 박막의 조성, 미세구조, 결정성, 그리고 전하저장용량에 미치는 영향을 고찰하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.272-275
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• 2017

최근 국내 대부분의 원자력 발전소 2차 계통 중 복수 탈염설비의 운전 시 pH를 제어하기 위해 에탄올아민(Ethanolamine, ETA)를 사용하고 있으나 ETA를 적용한 후 발생하는 폐수에 의한 방류수의 화학적 산소요구량(COD) 및 총 질소(TN)의 증가는 심각한 환경적인 문제를 발생 시킨다. ETA가 강이나 하천과 같은 수계로 유입되면 자연적으로 생분해되기 힘들고, 분해부산물이 증가되어 수질을 악화시킬 수도 있다. 이러한 문제점을 해결하기 위해 본 연구에서는 폐경석, 제강슬래그, 저회를 혼합하여 제올라이트화(zeolitization)과정을 통해 새로운 형태의 저비용, 고효율의 ETA 처리용 복합흡착제를 제조하였다. 최적의 흡착 및 이온교환능력을 갖는 복합흡착제는 폐경석, 제강슬래그 및 저회의 혼합조성비를 Mixture Analysis 통계법을 통해 도출하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.79-82
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• 2004

Propellant feeding system is the system to satisfy propellant feeding requirements(mass flow rate, pressure, temperature) at engine inlet of launch vehicle. Propellant feeding test facility is being constructed for the development scheme of pressurization system, processing in tank, propellant piping system, and flow control system that are main technologies in order to develope propellant feeding system. This paper introduces the propellant feeding test facility being constructed in KARI.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.479-483
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• 2012

This paper describes the development status of rocket engine test facility for the performance evaluation of liquid rocket engine of KSLV-II 1st stage. Design specification and composition of rocket engine test facility are suggested based on the design requirements. The results of the basic design of rocket engine test facility will be used as base data for the detail design and construction of rocket engine ground test facility of KSLV-II 75tonf liquid rocket engine.

• Annual Conference of KIPS
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• 2008.11a
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• pp.1246-1249
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• 2008

우리 나라는 고령화 사회로 접어들었고 그에 이어 초 고령화 사회가 예상되는 가운데, 실버 세대를 위한 체계적이고 실질적인 의료 환경이 요구 되고 있다. 독거노인과 거동이 불편한 노인들을 위하여 USN을 활용한 노인 건강관리 시스템(U-SilverCare)의 필요성이 급증하고 있다. 본 논문은 가속도 센서(Accelerometer Sensor), 혈중 산소포화도 센서 (POximeter Sensor), 심장박동센서(EKG Sensor)를 이용하여 실생활에서 일어날 수 있는 상황을 4가지로 구성, 실버 세대를 위한 U-SilverCare 응급상황 통보 시스템 시나리오를 구현하였다.

• Journal of the Korean GEO-environmental Society
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• v.5 no.4
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• pp.25-31
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• 2004

In conventional activated sludge process, COD fractions in wastewater are important parameters, significantly. Depending on characteristics of influent COD fractionation, activated sludge process requires a major change of a process operation to ensure meeting a stricter standards. In order to validate and evaluate the accuracy of the traditional COD fractionation methodologies, readily and slowly biodegradable COD was mixed using glucose and peptone as a sole carbon source in a synthetic wastewater, respectively. In this research, prediction of the COD fraction was made using the OUR(Oxygen Utilization Rate) and the NUR(Nitrate Utilization Rate) experiments. The result showed that COD fractions calculated by OUR experiment were similar to the composition of synthetic wastewater. On the other hand, it was found that an error was generated during the NUR experiment. This error was due to the intracellular storage period for storage microorganisms such as PAOs, and the error in COD fraction was observed about 8-14 % in terms of Total COD.

• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.151-156
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• 2003

Liquid rocket engine system is classified into an engine of pressurization and turbo pump type by the way of fuel fed-supporting system. In the KSR-III sounding rocket, an engine of pressurization type was used, but there was lots of technical problems to be solved for a use as the first stage engine of space launch vehicle. So, an engine of turbo pump type was required to be developed to overcome the technical limitation of liquid rocket engine. In this research, the analysis of propellant of Kerosine-LOX and methane-LOX which are noticed as a future propellant was carried out for the purpose of studying the basic characteristics. And to review the basic characteristics of an engine of turbo pump type, among the sizing variant of the space launch vehicle, the ways of injecting a satellite to a direct orbit and transient orbit were discussed in this paper.

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.63-72
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• 2010

MOV(Main Oxidizer shut-off Valves) control the combustion of launch vehicle systems by the supply and the isolation of liquid oxygen to a main combustion chamber in launch vehicle systems. Moreover, the MOV should secure a constant flow rate of liquid oxygen for combustion instability in the steady operational state. Although it has been showed that a EM(Engineering Model) with a high discharge coefficient value compared with the TM(Technology Model) fills the overall performance requirements, additional design modifications in some critical parts of the EM were conducted to improve the performance. The configurations of the pressure-control body, the middle flange, and the rips of the inlet body of the EM were modified and the performance tests have been performed with test models. Consequently, the intended improvements have been verified by the performance tests.