• Title/Summary/Keyword: Choi Yoon Sik

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Study on synthesis of carbon nanomaterials by hydrogen mixing in counterflow methane diffusion flames (메탄 대향류 확산화염내 수소를 첨가한 탄소나노물질 합성에 관한 연구)

  • Shin, Woo-Jung;Choi, Jung-Sik;Yoon, Seok-Hun;Lee, Hyun-Sik;Choi, Jae-Hyuk
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2011.10a
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    • pp.88-89
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    • 2011
  • The study on synthesis of carbon nanomaterials by H2 mixing in counterflow methane diffusion flames has been experimentally conducted. We have also investigated on effect of catalyst and temperature in flame. The counterflow flame was formed by many kind of gas (fuel side using $CH_4-H_2-N_2$ and oxidizer side $N_2-O_2$) and nitrogen shields discharge on each other side to cut off oxidizer of the atmosphere. Ferrocene was used as a metal catalyst for CNTs synthesis. substrate was used to deposit carbon nanomaterials and these were analyzed by FE-SEM. We could find that carbon nanotubes and many kind of carbon nano materials were formed in Cu wire substrate, through this experiment.

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Sulcusectomy and Soft Tissue Augmentation in Sulcus Vocalis (성대구(Sulcus vocalis)에 대한 구절제술(Sulcusectomy)과 연조직 삽입술)

  • Choi, Jong-Wook;Min, Heon-Ki;Choi, Gun;Jung, Kwang-Yoon;Seok, Yoon-Sik
    • Proceedings of the KSLP Conference
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    • 1996.11a
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    • pp.83-83
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    • 1996
  • 성대구는 성대점막 고유층의 일부 결손 또는 위축성 함입으로 유리연이 내함되어 성대궁형(bowing cord)이 형성되기 때문에 발성시 정상점막 파동이 소실되고 성문폐쇄부전을 보이며 그 결과 애성을 초래하게 된다. 이러한 성대의 내함을 교정하기 위하여 구절제술, 성대 상하순(upper and lower lip) 점막의 위치조절 둥이 시행되고 있으나 성대궁형이 교정되지 않아 음성개선에 실패하는 경우가 많다. 저자들은 구절제술 후 성대궁형을 교정할 목적으로 연골막을 포함한 연조직을 성대근 내측으로 삽입하여 음성을 개선하는데 도움을 얻고자 하였다. 이러한 방법으로 음성수술을 시행한 5례의 경험과 그 효과 및 문제점을 문헌고찰과 더불어 보고하고자 한다.

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Characteristics of the Running behavior and Safety for KTX due to Twist (수평틀림이 KTX 주행안전성에 미치는 영향 분석)

  • Choi, Il-Yoon;Lim, Yun-Sik
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.337-342
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    • 2011
  • Vehicle dynamic behavior should be investigated to establish the track irregularity criteria because they have an impact on vehicle dynamic behavior. The influence of twist on running behavior and safety for KTX was instigated by numerical analysis among track geometry quality parameters such as vertical alignment, lateral alignment, twist and track gauge in this paper. The wavelength and amplitude of twist were considered in scenario of this numerical analysis. This research is based on just numerical analysis and the final result which include measurement will be published in the future.

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