• Journal of the Korean Chemical Society
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• v.48 no.1
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• pp.99-102
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• 2004

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2000.05a
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• pp.87-92
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• 2000

이 연구에서는 단어를 지각하게 되면 그 단어에 대한 의미가 자동적으로 활성화되고 그림표상까지도 활성화되지만, 그림을 지각하고 난 후에는 의미표상체계는 활성화되지만 단어의 지각적 표상체계는 활성화되지 않는지를 살펴보고자 하였다. 실험 1과 2에서는 지연시간을 달리하여 그림을 지각적으로 처리를 하게 한 후 단어에 대한 점화효과를 보았으며, 실험 3 에서는 그림을 개념주도적 처리를 하게 한 후 단어에 대한 점화효과 및 암묵적 기억과 재인기억을 비교해 보았다. 실험결과 지각적 판단과제에서는 조건간의 아무런 차이가 없었지만, 의미적 판단과제에서는 동일조건과 그림조건에서의 반응시간이 통제조건을 포함한 기타 조건들에서보다 빠른 것으로 나타났다. 이러한 결과는 의미적 표상체계로부터 단어의 지각적 표상체계까지의 상호작용 통로가 존재하지 않으며, 그림자극이 단어자극의 점화효과에 영향을 주는 이유는 동일한 의미적 표상체계의 활성화가 단어자극의 지각적 표상체계까지 확산되기 때문이 아니라, 그림자극에 대한 의미적 표상체계가 활성화되기 때문이라는 점을 시사한다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.4
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• pp.703-707
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• 1989

The ignition of solid particle under strong convective heating has been investigated by applying an asymptotic analysis to a semi-infinite body for varying values of gas recovery temperature and convective heat transfer coefficient. It was found that if the scale of the reaction zone is much smaller than the characteristic length of the body size, then infinite body theory can be used to estimate the ignition delay time. Furthermore, the convective heat transfer coefficient was found to have more influence on predicting the ignition delay times of particle exposed to an incident shock wave rather than the gas recovery temperature.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1704-1709
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• 2004

New reduced chemical kinetic mechanism for prediction of autoignition process of HSDI diesel engine was investigated. For precise prediction of the ignition characteristics of diesel fuel, mechanism coefficients were fitted by the experimental results of ignition delay of diesel spray in a constant volume vessel. Ignition delay of diesel engine on various operation condition was calculated based on the new reduced chemical mechanism. The calculation results agreed well with experimental data.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.334-337
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• 2008

Three-dimensional unsteady reacting flowfield generated by transverse hydrogen injection into a supersonic mainstream are numerically investigated using DES and finite-rate chemistry model. Comparisons are made with experimental results to investigate the turbulent reacting flow physics. The numerical OH distribution describes well the experimental OH-PLIF result, while the numerical ignition delay time shows some disparity due to the restricted available experimental data.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.4
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• pp.79-88
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• 2020

Hypergolic propellants have been widely used for space propulsion systems based their long-term storability and high ignition reliability. Since conventional hypergolic propellants are highly toxic and carcinogenic, handling and operating costs are significant. To overcome the drawbacks, numerous studies have been actively performed to develope new hypergolic propellants, ensuring that the combinations are high performance, low toxicity and low environmental impact. In the present study, a comprehensive survey was conducted to summarize the research and development of green hypergolic propellants involving hydrogen peroxide, nitric acid, and ionic liquids.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.91-94
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• 2007

The fabrication and firing test of the ignition system for a micro solid propellant thruster are described in the present paper. Pt igniter coil was patterned on the glass membrane that was fabricated by the wet etching process. The thickness of Pt layer was $2000{\AA}$ and the width of igniter pattern was $40{\mu}m$. The thickness and diameter of glass membrane were $15{\mu}m$ and 1 mm, respectively. Ignition test was performed. Successful ignition of HTPB/AP propellant was obtained with an ignition delay of 1.6 s at an input voltage of 12 V. The ignition energy was estimated to be 1.4 J.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.6
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• pp.639-646
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• 2012

The characteristics of autoignited lifted flames in laminar jets of carbon monoxide/hydrogen fuels have been investigated experimentally in heated coflow air. In result, as the jet velocity increased, the blowoff was directly occurred from the nozzle-attached flame without experiencing a stabilized lifted flame, in the non-autoignited regime. In the autoignited regime, the autoignited lifted flame of carbon monoxide diluted by nitrogen was affected by the water vapor content in the compressed air oxidizer, as evidenced by the variation of the ignition delay time estimated by numerical calculation. In particular, in the autoignition regime at low temperatures with added hydrogen, the liftoff height of the autoignited lifted flames decreased and then increased as the jet velocity increased. Based on the mechanism in which the autoignited laminar lifted flame is stabilized by ignition delay time, the liftoff height can be influenced not only by the heat loss, but also by the preferential diffusion between momentum and mass diffusion in fuel jets during the autoignition process.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.5
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• pp.48-56
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• 2009

The auto-ignition tests of hybrid rockets with the concentrated hydrogen peroxide as an oxidizer were presented. Auto-ignition was successfully demonstrated by injecting decomposed gases from $H_2O_2$ into paraffin or polyethylene fuels. In addition, restart and instant ignition were realized with this rocket. For stable combustion, a higher $L^*$ value was required for the paraffin combustion compared with PE. On the other hand, much faster response time was demonstrated in case of a paraffin, which was 13 and 30 ms at ignition delay and rise time respectively.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.499-502
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• 2009

The auto-ignition tests of hybrid rockets with the concentrated hydrogen peroxide as an oxidizer were presented. Auto-ignition, restartability, and instant ignition were successfully demonstrated by injecting decomposed gases from $H_2O_2$ into paraffin or polyethylene fuels. In addition, much faster response time was demonstrated in case of a paraffin, which was 13 and 30 ms at ignition delay and rise time respectively.