• Title/Summary/Keyword: 상대기구학

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Kinematics of Automotive Gasoline Engine (자동차 엔진의 기구학)

  • 문대흥;이종섭
    • Journal of the korean Society of Automotive Engineers
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    • v.26 no.2
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    • pp.23-26
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    • 2004
  • 일반적인 기구학의 개념은 기계를 구성하는 부품의 상대운동을 연구하는 학문이다. 즉, 기구학은 기계를 구성하는 부품의 강성이나 힘 등은 배제하고 단지 기계를 구성하는 부품의 서로 상대적인 운동관계만을 연구하는 학문이다. 따라서 기구학 해석에 있어서도 변위, 속도, 가속도만을 연구하게 되며, 해석방법에 있어서도 과거에는 도식적인 방법을 사용했으나 최근에는 컴퓨터를 이용한 방법이 보편화되어 있다.(중략)

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Suspension and Kinematics (현가장치와 기구학)

  • 이언구
    • Journal of the korean Society of Automotive Engineers
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    • v.26 no.2
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    • pp.10-16
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    • 2004
  • 일반적으로 기구라 함은 어떤 한정된 상대운동을 할 수 있도록 각종 Joint로 연결된 여러 강체들의 조합을 의미한다. 또한 기구는 많은 기계적 장치들의 가장 중요한 설계인자중의 하나라 할 수 있는 기하학적 특성들을 구현할 수 있도록 구성되어지며, 그 기하학적 특성은 주로 주 관심 대상인 강체의 기준 강체에 대한 궤적 특성이라 할 수 있겠다.(중략)

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SAR 측정 및 교정기술에 관한 한국-일본 공동 연구

  • Kim, Gi-Hoe;Oh, Hak-Tae;Watanabe, S.
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.4 s.60
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    • pp.3-10
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    • 2006
  • 한국의 전파연구소와 일본의 정보통신연구기구는 휴대전화와 같은 이동통신기기로부터 방사되는 전자파가 인체에 흡수되는 에너지 정도를 측정하는 전자파 흡수율(SAR) 평가에 대한 오차 연구를 공동으로 수행하고 있다. 본 논문에서는 동종의 SAR 시스템에서 프로브, 교정용 도파관 및 기준 다이폴 안테나를 상호 교체하여 교정하여 프로브의 교정인자를 구하고 유효성 검사를 통하여 교정 오차를 검증하였다. 프로브 교정에 대한 상호 오차는 0.2 dB 이하의 결과를 얻었으며, 유효성 오차는 최대 0.28 dB를 얻었다. 그러나 SAR 외삽 알고리즘이 다를 경우는 최대 0.48 dB의 상대 오차를 보였다.

Study on Improving the Facilities of Power-Driven Water Leisure Crafts for the Deaf (청각장애인을 위한 동력수상레저기구 운영 개선방안에 관한 연구)

  • Won-Sam Choi;Bong-Kyu Jung;Cheor-Hong Park;Nam-U Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.836-842
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    • 2023
  • Under the Welfare of Disabled Persons Act, the national qualification test allows disabled and non-disabled people to appear for the same test, and the deaf do not fall under the reason for disqualification from obtaining a license for power-driven water leisure crafts; therefore, even the deaf can obtain a license. During a risk of collision at sea, ships and power-driven water leisure crafts notify the other party of dangerous signals such as maneuvering and warning signals through sound signals to prevent accidents that may occur because surrounding ships are not visible. However, a method is required to prevent marine accidents that may occur when the deaf cannot hear danger signals through sounds from nearby ships or power-driven water leisure crafts during leisure activities owing to hearing impairment. A sound reception system is a device installed on a ship where missionary work is completely deposed to display the amplification of external sounds and the direction of sound reception on the screen. Through visual display of sound signals such as dangerous signals that cannot be heard owing to hearing impairment, improvement measures were proposed to prevent marine accidents that can occur owing to the inability of the deaf to check sound signals during leisure activities.

Diurnal and Seasonal Variation of Chlorophyll Fluorescence from Korean Fir Plants on Mt. Halla (한라산 구상나무 잎의 엽록소형광의 일변화와 계절적 변화)

  • 오순자;고정군;김응식;오문유;고석찬
    • Korean Journal of Environmental Biology
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    • v.19 no.1
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    • pp.43-48
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    • 2001
  • Chlorophyll fluorescence of needles of Korean fir (Abies koreana) plants and environmental factors of their natural habitat were investigated in order to obtain the information for environmental adaptation and conservation of Korean fir plants. The photochemical efficiency of photosystem II, Fv/Fm, of Korean fir needles was significantly low (0.19-0.36) in the winter, whereas it was high (0.8-0.86) in the summer. The Fv/Fm value of the winter was slightly higher at mid-day than at dawn, suggesting that mid-day environmental conditions of the winter were favorable on needles of Korean fir plants. In contrast, the mid-day Fv/Fm value of the summer maintained high (around 0.8). It indicates that mid-day environmental conditions of the summer did not induce photodamage, although it caused a slight decrease in the Fv/Fm values. The non-photochemical fluorescence quenching (NPQ) of Korean fir needles was very low (0-0.01) all through the day in the winter. However, it was high (0.76) at mid-day in the summer. These results suggest that Korean fir plants have a system for the protection of PS II from mid-day environmental stresses of the summer. In the winter, the Fv/Fm values were positively correlated with temperature, light intensity and relative humidity, although NPQ values showed no correlation with any of them. In the summer, the Fv/Fm values were positively correlated with relative humidity but negatively correlated with temperature and light intensity. These results indicate that increase of tempera-ture, light intensity and relative humidity lead to promotion of the photochemical efficiency in the winter and high temperature and light intensity may cause photoinhibition in the summer.

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A Study on the Polishing Characteristics of LCD Glass (LCD 유리기판 폴리싱 가공특성에 관한 연구)

  • Lee, Sang-Min;Lee, Choong-Seok;Chae, Seung-Su;Kim, Taeck-Su;Park, Hwi-Keun;Lee, Jong-Chan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.8 no.1
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    • pp.77-82
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    • 2009
  • This paper reports a kinematic analysis and experimental results for the polishing process of G7 LCD glass. A kinematic analysis for the relative motion of the upper plate and lower plate has been done and computer simulation has been programmed. A series of polishing experiments has also been carried out and compared with analytical data. The experimental results agreed well with analytical ones. The experimental results indicate that the polishing removal is proportional to the relative speed and pressure.

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Growth Performance and Photosynthesis of Two Deciduous Hardwood Species under Different Irrigation Period Treatments in a Container Nursery System (시설양묘과정에서 관수 주기 처리에 따른 두 활엽수종의 생장 및 광합성 기구 변화)

  • Cho, Min-Seok;Lee, Soo-Won;Hwang, Jae-Hong;Kim, Jae-Won
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.14 no.1
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    • pp.28-38
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    • 2012
  • This study was conducted to investigate growth performance, photosynthesis, water use efficiency (WUE), and stomatal conductance ($g_s$) of container seedlings of Liriodendron tulipifera and Zelkova serrata growing under three different irrigation periods (1 time/1 day, 1 time/2 days and 1 time/3 days) for high seedling quality. The root collar diameter and height of L. tulipifera and Z. serrata seedlings were highest with 1 time/1 day irrigation, whereas they were lowest with 1 time/3 days irrigation. The two species showed low drought tolerance. As irrigation period was shortened, biomass and seedling quality index (SQI) of the two species increased. The ratio of height to root collar diameter (H/D) and the ratio of below to aboveground biomass (T/R) of the two species were lower with 1 time/3 days than at other irrigation periods. L. tulipifera and Z. serrata seedlings showed significantly higher photosynthetic capacity with 1 time/1 day irrigation. As irrigation period was shortened, $g_s$ of two species increased, while their WUE decreased significantly (P<0.05) These results show that 1 time/1 day irrigation provides the most optimal water condition for container seedling production of two species and irrigation controlling is very important for growth and quality of container seedlings.

A Study of Long-term Development Plan of Korea Research Institute for Library and Information ("도서관연구소" 중장기 발전방안 연구)

  • Yoon, Hee-Yoon
    • Journal of Korean Library and Information Science Society
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    • v.39 no.2
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    • pp.5-27
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    • 2008
  • The purpose of this paper Is to present a long-term development plan for the KRILI(Korea Research Institute for Library and Information). To do so, authors analysed a various library research institutes and related organizations in U.S.A., U.K., Czech Republic, Hungary, and Japan. And using the SWOT analysis, author identified and described the current status and also surveyed recognition of library and information science faculties as to desirable roles and phase of the KRILI. Based on the results of analysis and survey, this paper suggested a long-term plan(vision and objectives, strategic issues, desirable phase and organization system, growth and development model, Internal cooperative operating systems and external research cooperation system, etc.) of the KRILI.

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