• Title/Summary/Keyword: tubes

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TUBES OF FINITE CHEN-TYPE

  • Al-Zoubi, Hassan;Jaber, Khalid M.;Stamatakis, Stylianos
    • Communications of the Korean Mathematical Society
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    • v.33 no.2
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    • pp.581-590
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    • 2018
  • In this paper, we consider surfaces in the 3-dimensional Euclidean space $\mathbb{E}^3$ which are of finite III-type, that is, they are of finite type, in the sense of B.-Y. Chen, corresponding to the third fundamental form. We present an important family of surfaces, namely, tubes in $\mathbb{E}^3$. We show that tubes are of infinite III-type.

A Theoretical Study on the Boiling Heat Transfer Performance of Tubes with Extended Surfaces (확대 전열관의 비등열전달에 관한 이론적 연구)

  • Jho, S.G.
    • Solar Energy
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    • v.19 no.2
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    • pp.45-56
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    • 1999
  • The performance of vertical and horizontal tubes with extended surface of rectangular and triangular cross section was investigated theoretically for boiling heat transfer. A simple method for numerical program assuming one-dimensional heat flow was used to predict the performance of these extended surface tubes. The object of this study was to predict the effects of the height, thickness, numbers and, clearance of the extended surface on boiling heat transfer. The results showed that extended surfaces are quite effective as compared to plane surfaces especially near the bum-out point and to promote heat flux in boiling heat transfer.

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LED-based illuminated V-core optical engine

  • Chen, Chin-Chung;Mo, Chi-Neng;Wu, Shih-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.560-563
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    • 2006
  • LED is promising for the application of specialty illumination. Thiscolor management system, V-core, with LED light sources and the structure of V-core for LCoS projector has been proposed to improve the primary saturation, uniformity and contrast. We designed the high efficient LED modules for high brightness requirement. The LED module can operate in narrow-direction indicator, $12^{\circ}$.

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A 2.4-in QVGA p-Si LTPS AMLCD for Mobile Application

  • Chen, Yu-Cheng;Lin, Tai-Ming;Hsu, Tien-Chu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1029-1032
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    • 2005
  • A 262K-color QVGA LTPS AMLCD was developed. This panel has integrated gate driver and data multiplexer (1:3) by p_Si LTPS TFT process. The commercialized driver IC was adopted to implement this display. Fine image quality, low powerconsumption and cost-efficiency feature make the panel be suitable for mobile application.

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Fatigue life estimation of $CO_2$ gas arc welded carbon steel tubes ($CO_2$ 가스 용접된 강관파일의 피로수명)

  • 이억섭;김동준;김승권
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.665-669
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    • 1997
  • In this study, the fatigue lives of two kinds of specimens made by co/sab 2/ gas were assessed. The materials for two kinds of specimens were taken out of the virgin carbon steel tubes and used carbon steel tubes, respectively. As a result, it was found that the fatigue lives of two groups of specimens were in the same order of magnitude.

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Fatigue Life Estimation of $CO^2$ Gas Arc Welded Carbon Steel Tubes ($CO^2$ 가스 용접된 강관파일의 피로수명 평가)

  • 이억섭;김동준;김승권
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.1
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    • pp.13-18
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    • 1998
  • In this study. the fatigue lives of two kinds of specimens made by $CO^2$ gas weld were assessed. The materials for two kinds of specimens were taken out of the virgin carbon steel tubes and the used carbon steel tubes respectively. As a result, it was found that the fatigue lives of two groups of specimens were in the same order of magnitude.

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Study of compression characteristics for hydroformed tubes(II) (Hydroformed 튜브 소재의 압축특성에 관한 연구(II))

  • 박세승;손현성;이영선;이우식;김영석
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.05a
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    • pp.17-20
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    • 2002
  • Recently tube hydroforming technology has been one of the most important technology in automotive industry in the point of saving weight and high quality for collision accidents. In this paper, experimental studies for axial compression tests of hydroformed tubes are performed to investigate the collapse absorption characteristics. The collapse absorption abilities are discussed and compared for as-received, hydroformed, and press formed tubes.

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Morphology of Halloysite Particles and Aggregates in the Weathering of Anorthosite (회장암 풍화과정에서 생성되는 할로이사이트 입자 및 집합체의 형태)

  • 정기영;김영호
    • Journal of the Mineralogical Society of Korea
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    • v.9 no.2
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    • pp.64-70
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    • 1996
  • Early weathering products of anorthosite were investigated by using scanning electron microscopy in order to trace the development of halloysite particles and aggregates. Tiny short tubes or spheres precipitate on the plagioclase surface in the initial stage of weathering and form the compact globular aggregates. With continued growth, several globules are coalesced into wrinkled halloysite aggregates, and short tubes or spheres in globules grow into long tubes forming sheaf-like aggregates. Particle shape of halloysite varies with changing supersaturation degree of weathering solution, and determines the morphology of halloysite aggregates.

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New Structure to Enhance the Light Efficiency in LCoS Optical Engine

  • Huang, Chi-Wei;Mo, Chi-Neng;Wu, Shih-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.744-747
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    • 2005
  • The exploitable efficiency of UHP is very important in a projection system. We always use lens array for light shaping and energy distribution transformation in conventional projection system. Because of the limitation of arc gap and F/# of elements, the utilize efficiency is always dismal. In this paper we try to bring out a new method to reduce the sparkle formed on the PS converter and enhance the system efficiency.

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The improvement of contrast on LCOS system

  • Chen, Hun-Wei;Wu, Shih-Min;Mo, Chi-Neng
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.740-743
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    • 2005
  • The discussion of this study is that we proposed a new construction to improve the potency of LCOS projection monitor. We suggest a new construction that uses special optics coating to reduce the green channel and obtains a purer white field. Compared with the voltage method to adjust on the monitor, we can get higher contrast gradient.

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