• 제목/요약/키워드: Young-Hoon Kim

검색결과 9,791건 처리시간 0.052초

회전 아크를 이용한 메탄 개질 반응에서 플라즈마 모드에 따른 개질 특성 (Characteristics of $CH_4$ Reforming by Rotating Arc)

  • 김동현;이대훈;김관태;송영훈
    • 한국연소학회지
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    • 제11권2호
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    • pp.15-21
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    • 2006
  • Characteristics of a plasma reactor for partial oxidation of methane, especially focused on the role and effectiveness of plasma chemistry, are investigated. Partial oxidation of methane is investigated using a rotating arc which is a three dimensional version of a typical gliding arc. Three different modes of operation were found. Each mode shows different reforming performance. The reason for the difference is due to the difference in relative role of thermal and plasma chemistry in overall process. A mode with high temperature results higher methane conversion and hydrogen selectivity in contrast to the mode with lower temperature where poor methane conversion and higher selectivity of $C_2$ species are observed. In this way, we can confirm that by controlling characteristic of process or controlling relative strength of plasma chemistry and thermal chemistry, it is possible to map an optimal condition of reforming process by rotating arc.

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메탄 개질에서의 회전 아크 플라즈마 특성 (Characteristics of Rotating arc Plasma in $CH_4$ Reforming)

  • 이대훈;김관태;차민석;송영훈;김동현
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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    • pp.144-148
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    • 2006
  • Characteristics of a plasma reactor for partial oxidation of methane, especially focused on the role and effectiveness of plasma chemistry, is investigated. Partial oxidation of methane is investigated using a rotating arc which is a three dimensional version of a typical glidingarc. The rotating arc has both the characteristics of equilibrium and non-equilibrium plasma. Non-equilibrium characteristics of the rotating gliding arc can be increased by rotating an elongated arc string attached at both the tip of inner electrode and the edge of outer electrode. In this way, plasma chemistry can be enhanced and hydrogen selectivity can reach almost 100% that is much higher than thermal equilibrium condition. As a result, the present study enables the strategic approach of the plasma reforming process by means of appropriate reactor design to maximize plasma effect and resulting in maximized reaction efficiency.

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Immunomodulating Activity of a Polysaccharide Isolated from Mori Cortex Radicis

  • Kim, Hwan-Mook;Han, Sang-Bae;Lee, Ki-Hoon;Lee, Chang-Woo;Kim, Chul-Young;Lee, Eun-Ju;Huh, Hoon
    • Archives of Pharmacal Research
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    • 제23권3호
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    • pp.240-242
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    • 2000
  • The immunomodulating activity of a polysaccharide isolated from Morus alba (PMA) root bark was examined in murine splenic lymphocytes. PMA enhanced proliferation of splenic lymphocytes in a synergistic manner in the presence of mitogens. However, PMA suppressed pri-may IgM antibody production from B cells, which was activated with lipopolysaccharide, a polyclonal activator, or immunized with a T-cell dependent antigen sheep red blood cells. Our observations showed that the immunomodulating activity of PMA increased lymphocyte proliferation and that PMA decreased antibody production from B cells, which was distinct from those of other plant-originated polysaccharides.

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The Movement Monitoring of Structures using GPS

  • 손호웅;(SeokHoonOh);(YoungKyungKim)
    • 지구물리
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    • 제7권4호
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    • pp.325-330
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    • 2004
  • For the monitoring of structures, it is desirable for the measurement system to deliver equal precision in all components. When using GPS the accuracy, availability, reliability and integrity of the position solutions is very dependent on the number and geometric distribution of the available satellites. Therefore the positioning precision is not the same in all there component, and large variations (in positioning) precision can be expected during a 24-hour period. This situation becomes worse when the line-of-sight to GPS satellites becomes obstructed, such as in urban environments. Pseudolites can be sed to augment GPS and improve a geometrically weak satellite constellation. The use of pseudolites as supplement(s) of GPS for the movement measurement of bridges is demonstrated in this paper. It is shown that pseudollites can improve the vertical position components.

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기계독해 기반 한국어 의존 파싱 (Korean Dependency Parsing as Machine Reading Comprehension)

  • 민진우;나승훈;신종훈;김영길;김강일
    • 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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    • 한국정보과학회언어공학연구회 2021년도 제33회 한글 및 한국어 정보처리 학술대회
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    • pp.270-273
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    • 2021
  • 한국어 의존 파싱은 전이 기반 방식과 그래프 기반 방식의 두 갈래로 연구되어 왔고 그 중 그래프 기반 의존 파싱 방법은 문장 내의 모든 단어에 대해 인코딩한 후 지배소, 의존소에 대한 MLP를 적용하여 각각 표상을 얻고 Biaffine 어텐션을 통해 모든 단어 쌍에 대한 그래프 점수를 얻고 트리를 생성하는 방법이 대표적이다. Biaffine 어텐션 모델에서 문장 내의 각 단어들은 구문 트리 내의 서브트리의 역할을 하지만 두 단어간의 의존성만을 판단하기 때문에 서브 트리의 정보를 이용할 수 없다는 단점이 존재한다. 본 연구에서는 이러한 단점을 해결하기 위해 제안된 Span-Span(서브트리-서브트리)로의 서브트리 정보를 이용할 수 있도록 하는 기계 독해 기반 의존 파싱 모델을 한국어 구문 분석 데이터 셋에 적용하여 소폭의 성능향상을 얻었다.

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경사/장애물/특수 표면을 이동할 수 있는 얀센 매커니즘 기반의 보행기구 설계 (Pass obstacle walking robot using Jansen mechanism)

  • 송치광;박정빈;최훈;김종혁;안현겸;이건희
    • EDISON SW 활용 경진대회 논문집
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    • 제5회(2016년)
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    • pp.477-480
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    • 2016
  • Based on the Jansen mechanism theory, a walking robot is developed, which is able to overcome the given obstacles. Taking joint positions and leg directions as design parameters, the walking robot is analyzed. In order to analyze and optimize the leg motion, Edison program and Jansen mechanism optimization solver are used, respectively. It is found that Edison program is so effective to determine joint variables and position of leg direction. With the help of these programs, lots of trials or errors could be saved.

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