• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.361-370
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• 2021

Carbon fiber reinforced polymer (CFRP) is one of the composite materials, which has a unique property that is lightweight but strong. The CFRPs are widely used in various industries where their unique characteristics are required. In particular, electric and unmanned aerial vehicles critically need lightweight parts and bodies with sufficient mechanical strengths. Vehicles using the battery as a power source should simultaneously meet two requirements that the battery has to be safely protected. The vehicle should be light of increasing the mileage. The CFRP has considered as the one that satisfies the requirements and is widely used as battery housing and other vehicle parts. On the other hand, in the battery area, carbon fibers are intensively tested as battery components such as electrodes and/or current collectors. Furthermore, using carbon fibers as both structure reinforcements and battery components to build a structural battery is intensively investigated in Sweden and the USA. This mini-review encompasses recent research trends that cover the classification of structural batteries in terms of functionality of carbon fibers and issues and efforts in the battery and discusses the prospect of structural batteries.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.91.2-91.2
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• 2010

SOFC는 높은 반응온도($600{\sim}1000^{\circ}C$)에서 작동되어 발전효율이 높고 다양한 연료를 사용할 수 있는 것이 장점이다. 하지만 고온에서의 운전은 구성요소의 열변형과 온도구배에 의한 전극촉매의 열화 그리고 밀봉재의 수명에 영향을 주어 결국 스택의 내구성을 감소시킨다. 특히 스택의 온도구배가 심화되면 국부적인 Hot spot를 형성하여 셀에 심각한 손상을 주게 된다. 본 과제에서는 SOFC 스택의 온도구배를 완화시키기 위한 내부개질기의 개발 및 고온용 분리판 소재의 정밀성형기술을 확보하고자 한다. 열/유동해석을 통하여 반응가스의 농도, 유속, 구조변경 등 내부개질기 온도구배에 대한 주요인자를 확인하였고, 장기 운전평가를 통하여 개질 촉매의 고온 활성 및 내구성에 대한 성능평가를 진행 중이다. 분리판의 경우, 고온용 소재(페라이트계 스테인레스)에 대한 기초실험을 실시하여 성형품질의 주요 인자를 파악하였으며 Proto-type 금형 설계 및 개발을 통하여 성형 기초기술을 확보하였다. 그리고 스택 내부온도를 구현할 수 있는 시뮬레이터를 설계 중에 있으며 이를 이용하여 개발된 내부개질기 및 분리판을 스택 운전환경에서 평가할 예정이다.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.3
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• pp.201-208
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• 2006

An alternative to the nuclear and fossil fuel power is renewable energy technologies (hydro, wind, solar and ocean), and the research about the highest efficiency machinery have been processed. The high-power LED is the representative one among those. In this paper, a high efficiency lighting system using a battery charged with solar or wind power is proposed for a high power LED. And a new efficient converter called 'Back-boost' is proposed. The validity of the lighting system scheme is verified by experimental results based on a laboratory prototype.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.919-920
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• 2014

따개비(barnacle)는 선저부에 붙어서 번식하며 딱딱한 석회질 껍데기로 덮여있다. 이로 인하여 선박의 속도를 저하시키고 도료기능을 상실시키는 주요인이 된다. 이를 제거하기 위해 작업자가 직접 액체를 분사하고 브러쉬로 세척해야 한다는 불편함과 위험에 노출되기 때문에 선박작업용 로봇이나 기계들이 많이 개발되고 있다. 현재 연구 중이거나 개발이 완료된 것 중에는 영구자석 또는 전자석 휠을 사용하거나 공압을 이용하여 수직벽면에서 작업을 한다. 특히 공압 방식을 많이 사용하였는데 수직벽면에 로봇이 밀착될 만큼 강한 공압이 필요하게 되기 때문에 부가적인 장치가 많이 필요하다. 본 논문에서는 부가적인 장치를 최소화하고 효과적인 동작을 하기위해 전자석 방식을 선택 하였으며 간편하게 선박의 수직벽면을 작업할 수 있는 전자석 방식의 4륜 로봇을 개발하고자 한다. 선박의 수직벽면 작업용 4륜구동 로봇을 전자석을 이용하여 수직벽면에 부착할 수 있도록 설계하였으며 자력의 세기와 방향을 제어하여 로봇이 선박의 수직면에 밀착되어 자유롭게 이동이 가능하도록 개발 하고자 한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.9
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• pp.665-677
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• 2019

The United States has implemented the TLCSM (Total Life Cycle System Management) to minimize the total lifecycle cost of aircraft and to improve operating availability. As a practical strategy, CBM + is required to be applied to new weapons systems. The F-35 aircraft applied PHM under CBM + concept from the development stage. In this study, we analyzed the technology trends, the level of PHM technology in Korea, and the development trends of foreign technology. Then, we analyzed the PHM technical elements and constructed the 5 phases of technical elements acquisition roadmap for military fixed wing aircraft parts PHM.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.9
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• pp.1206-1213
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• 2021

A drone invented for the military has been increased the range of application with the development of relevant technology, and it influences to include the private area. Currently, the use of drone has been increasing in many areas, such as agriculture, unmanned parcel service, production of image contents, and architecture. In 2021, South of Korea, a drone certificate system for drone flight is introduced and on operation. In case of drone flight with the maximum takeoff weight as 2kg or up, the flight experience and practical examination are required, whereas in case of drone lighter than 2kg, the online education qualification is enough to operate it without the flight experience and practical examination. Recently, the drone related accidents have been increasing with the rapidly supply of camera drones with the maximum takeoff weight as less than 2kg. This paper introduces the characteristics of the camera drone to meet burgeoning demand, and discusses an education plan for the camera drone.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.3
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• pp.251-256
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• 1981

Silage yield and nutritional values of a locally collected Korean corn line with high tillering and earing characteristics were investigated at plant densities from 2778 to 8333 plants/ l0a. This line and a non-tillering and nonprolific corn as a check were grown at four plant densities and at three planting dates. The Korean local line abbreviated as MET had the highest dry matter per l0a. The highest dry matter of the MET line compared with the check hybrid was due to the highest dry leaf weight of the MET line. The highest dry leaf weight of the MET line was due to the increased number of tillers of the MET line. Other plant parts such as ear weight, kernel weight and cob weight of the MET line were lower than those of the check hybrid. The dry husk weight per l0a of the MET line was higher than that of the check hybrid, probably due to the increased number of ears in the MET line. The total embryo production per 10 a of the MET line was significantly higher than that of the check hybrid. The increased portion of embryo of the MET line is probably responsible for the higher TON values of the MET line. No interaction between variety x planting dates or planting density was found, indicating that the MET line and check hybrid were both the same in effects of planting dates and densities. Both line and hybrid showed the highest dry matter production when the planting density was high and planting dates was early. When silage was made from either MET line or check hybrid the nutritional values in terms of crude protein, crude fat, fiber, and ash contents of the MET line were similar to those of the check hybrid. But the TON of the MET line was higher than that of the check hybrid, while the OCP of the MET line lower than that of the check hybrid. Amino acid contents of the MET line were also comparable to those of the check hybrid, while lysine content of the MET line was 10% higher than that of the check hybrid.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.1
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• pp.21-28
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• 2004

We have demonstrated a low speed weigh-in motion system using FBG sensors and performed field test at a trial road. Technique, called identical chirped grating interrogation, have used for a demodulation relying on the mismatching of two identical broadband chirped gratings. We compensated the fluctuation of LED power and the temperature of sensor and used a lock-in amplifier to reduce effect of noise. We could design a bending plate that the measurement results are independent of position of weight. The FBG sensors weigh-in motion system showed linearity and reproducibility.

• Resources Recycling
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• v.15 no.1 s.69
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• pp.58-65
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• 2006

A new technology for refused derive fuel(RDF) utilization in circulating fluidized bed is under development. The RDF is tested in a bench scale circulating fluidized bed(CFB) combustor and its burning characteristics were investigated and collected as design parameters. The combustions were controllable and the HCl emission which is most important toxic emission were below 150 ppm at the exit of the combustor. The differences between conventional coal homing circulating fluidized bed boiler and the exclusive RDF boiler were studied and commercial scale co-generation CFB for RDF was designed.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.626-629
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• 2007

국내외에 아직 개발 실적이 없는 발전소의 해수방류수를 이용한 조류식발전시스템의 개발을 위하여, 현재 하동화력발전소 해수방수로를 대상으로 헬리컬 수차를 이용한 조류식발전 시험설비를 제작 완료하고, 성능 시험이 진행 중이며, 본 연구에서는 성능 시험 과정에서 나타난 제반 문제점을 제시하고 그에 대한 원인 및 대책을 분석해 보았다. 본 시험설비는 인공수로에서 수평 배열 헬리컬수차로서 기계장치의 안정성 및 수차의 효율을 평가하고자 하였다. 조류식 시험장치는 배수로의 빠른 유속으로 인하여 시공이 매우 어려웠으며, 인공수로임에도 불구하고 유지관리를 위한 적정 구조 선정이 곤란한 상황이었다. 또한, 헬리컬 수차는 서로 직렬연결되어 운전할 수 있는 장점이 있으나, 본 연구와 같이 다수의 수차가 연결될 경우, 보다 높은 축정렬 정확성, 커플링, 베어링 정밀도 등이 요구되어 효율 감소의 원인이 됨을 확인하였다. 본 장치는 시험용으로서 정밀한 베어링 및 수밀구조, 증속장치를 채택하지 않았으나, 상업용에서는 이를 개선할 필요성이 있다고 판단된다. 또한, 수차의 설치와 유지관리 조건 향상, 수차 통과부의 유황 개선, 수차의 효율 향상을 위하여 조류식 수차에도 유도수로와 casing, draft tube와 같은 Confined flow 구조를 일부 채택할 필요성이 있다고 판단된다.