• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.474-478
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• 2010

Hybrid rocket combustion experiments using liquefying diaphragm made by blended liquefying fuel with 10 wt% of LDPE were performed. Results of experiments were compared to the those of pure paraffin. In case of using liquefying diaphragm, regression rate of rear fuel grain, characteristic velocity and specific impulse highly increased due to the induced turbulent intensity and heat transfer. The serious combustion instability was not observed in analysis of combustion instability. These results can imply that the liquefying diaphragm is efficient to improve low combustion efficiency in hybrid rocket using liquefying fuel.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.1
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• pp.40-47
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• 2013

The similarity in internal flow of solid and hybrid rocket suggests that hybrid rocket combustion can be susceptible to instability due to vortex sheddings and their interaction. This study focuses on the evolution of interaction of vortex generated in pre-chamber with other types of vortex in the combustor and the change of combustion characteristics. Baseline and other results tested with disks show that there are five different frequency bands appeared in spectral domain. These include a frequency with thermal lag of solid fuel, vortex shedding due to obstacles such as forward, backward facing step and wall vortices near surface. The comparison of frequency behavior in the cases with disk 1 and 3 reveals that vortex shedding generated in pre-chamber can interact with other types of vortex shedding at a certain condition. The frequency of Helmholtz mode is one of candidates resulting to a resonance when it was excited by other types of oscillation even if this mode was not discernable in baseline test. This selective mechanism of resonance may explain the reason why non-linear combustion instability occurs in hybrid rocket combustion.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.439-445
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• 2006

For investigating self-diagnosis applicability, a method based on monitoring the changes in the electrical resistance of hybrid FRP(having electrical property) reinforced concrete has been tested. Then after examining change in the value of electrical resistance of carbon fiber in CFRP(non-hybrid type), CFGFRP and CFAFRP(hybrid type) before and after the occurrence of cracks and fracture in non-hybrid and hybrid FRP reinforced concrete at each flexural weight-stage, the correlations of each factors(the changes in electrical resistance and load as a function of strain, deflection) were analyzed. As the results, it is clarified that when the carbon fiber tows fracture, the electrical resistance of it increase largely, and afterwards hybrid FRP composites can be resist the load due to the presence of the reinforced fiber, for example, glass fiber or aramid fiber tows. Therefore, it can be recognized that hybrid FRP(including carbon fiber) reinforcing bar could be applied for self-diagnosis of fracture in reinforced FRP concrete fracture.

• Fire Science and Engineering
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• v.31 no.4
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• pp.12-19
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• 2017

The present paper is a study on the performance characteristics of organic-inorganic hybrid flame retardants. MDF plywood has been used, that are being used for the interior decoration of building structures, to make the samples for experiment according to the existing or non-existing treatment of organic-inorganic hybrid flame resistants. Later, the experiment on the measurement of flame retardant performance using a $45^{\circ}$ flammability tester and the experiment on the measurement of combustion characteristic using a cone calorimeter have been proceeded to confirm the performance characteristic of organic-inorganic hybrid flame retardants. From the result of experiments, it has been confirmed that both organic-inorganic hybrid flame retardants have merits of inorganic and organic substances, and that heat resistance, durability and adhesiveness have been largely improved. The performance on the flame retardant has also appeared with excellent effect such as the reduced generation of combustion gas and the decreased generation of smoke.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.534-537
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• 2008

하이브리드자동차의 연료소비율 시험 시 초기 SOC 조건에 따른 SOC와 연비 변화 특성을 파악하기 위해 2종의 차종을 선택하여 UDDS 모드주행 실험을 실시하였다. 실험결과 Strong type 자동차는 주행시작 약 550초 경과 후 SOC 52 $\sim$ 54%로 수렴하였다. 또한 일반 시가지 주행조건에서는 SOC를 50$\sim$55 % 범위에서 제어함을 알 수 있으며, 초기 SOC 조건에 따라 연비는 약 79%의 편차가 나타났다. 이는 저속구간에서 순수 전기자동차 구동이 구현됨으로써 SOC 70%에서 큰 연비 상승 효과가 나타나는 것으로 판단 된다. Mild type 자동차는 연비가 초기 SOC 조건에 따라 약 5%의 편차가 나타남을 알 수 있었으며, SOC 변화특성은 배터리 충전상태에 따라 충전량 제어는 이루어지나 가속 시 어시스트만 이루어지는 시스템적 특성상 효율적인 SOC 제어가 이루어지지 않아 연비에는 큰 영향을 주지 않는 것으로 생각된다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04a
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• pp.61-62
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• 2008

최근 유가 상승의 영향으로 많은 연구자들의 관심이 풍부하고 무한한 태양에너지의 활용에 많은 관심이 쏟아지고 있다. 하지만 현재 상용화된 실리콘 태양전지는 실리콘의 정제 및 제조 단가가 생산 비용에 많은 부분을 차지하여 시장진입에 어려움을 겪고 있다 또한 실리콘의 생산과 가공이 반도체나 디스플레이 분야에서도 반드시 필요하기 때문에 그에 따른 생산량이 전체 소비를 따라 가지 못하여 나타나는 공급 부족 현상도 상당 기간 지속 되었다. 이러한 상황에서 실리콘을 대처할만한 태양전지의 개발과 함께 휴대성이 뛰어난 태양전지의 개발이 많은 관심을 끌고 있다. 본 연구에서는 기존의 유기 태양전지에 CNT를 혼합한 유무기 하이브리드 태양전지를 제조하고 그에 따른 광학적 특성과 전기적 특성을 살펴보았다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.93-96
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• 2008

This study was performed for merge characteristic of Hybrid Rocket with multi-port. PE(Poly Ethylene) is fuel with 4 and 5 port grain and GOX(Gas Oxygen) is oxidizer. This study according to number of ports The multi-port grain merge with other grains during a combustion, then Hybrid Rocket performance is changed by change of a combustion area.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.262-265
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• 2003

This Study is focused on the instrumenting Hybrid Rocket Motor of ACPL at Konkuk University and researching combustion instability by measuring regression rate versus oxidizer mass flux. In the result of experiment, test fire was moderate and we could acquire data of pressure, thrust, and temperature of combustion chamber. In the future, studying unsteady change of regression rate and pressure characteristic analysis of combustion chamber through hundreds of experiments should be performed. furthermore, researching characteristic velocity by taking a measurement of combustion temperature will be inevitable.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.734-736
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• 2015

본 논문은 비균일 공극형 단상 4/4극 하이브리드 스위치드릴럭턴스 전동기(이하, HSRM)를 제안한다. 제안된 HSRM의 회전자 형상은 비균일한 공극을 갖는 형상으로 데드존 구간과 토크리플, 출력특성에 기여한다. 이와 같은 특성을 검증하기 위해 균일한 공극을 갖는 단상 하이브리드 SRM의 토크 및 출력특성을 유한요소해석(FEA)을 통해 비교하였다. 그 결과 제안된 HSRM을 제작하였고 시험 결과를 통해 그 타당성을 검증하였다.

• Membrane Journal
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• v.14 no.2
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• pp.132-141
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• 2004

NBR-Clay hybrid membranes were prepared by melt intercalation method with internal mixer and two roll mills. MMT was intercalated or ekfoliated by the NBR and it was confirmed by X-ray diffraction method. D-spacing of the characteristic peak from MMT plate in WAXD was moved and diminished. Gas permeability, mechanical properties and thermal properties of the NBR-Clay hybrid membranes were investigated. Gas permeability through the NBR-Clay hybrid membranes decreased due to increased tortuosity made by intercalation of clay in NBR.