• Title/Summary/Keyword: 튀어오름

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Crashworthiness Evaluation of Motorized Trailer of High Speed Train (고속전철 동력객차의 충돌성능평가)

  • Kim, Heon Young;Han, Jae Hyung;Lee, Jong Keun
    • Journal of Industrial Technology
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    • v.18
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    • pp.225-232
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    • 1998
  • Train crashes involve complex interaction between deformable bodies in multiple collisions. The purpose of this study is to suggest the effective analytical procedure using finite element model for the crashworthiness of motorized trailer of high speed train. Various types of crash events are investigated and the conditions for numerical simulation are defined. Finally korean high speed train which consists of aluminum members can be analyzed and designed by the numerical simulation.

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Temperature Dependence of the Electrical Activation Energy and Defect Density in Undoped Amorphous Germanium (a-Ge : H) (비정질 게르마늄(a-Ge : H)의 전기전도 활성화에너지 및 결함밀도의 온도의존성)

  • Jo, U-Seong;Yu, Jong-Hun
    • Korean Journal of Materials Research
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    • v.5 no.6
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    • pp.639-643
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    • 1995
  • The temperature dependence of the dark conductivity was studied on undoped hydrogenated amorphous germanium (a-Ge : H) over the range from 297 to 423 K. The pre-exponential factor $\sigma$$\_$0/ and activation energy E$\_$C/-E$\_$F/ are determined by an Arrhenius plot. The Arrhenius plot of the electrical conductivity shows a kink around the kink temperature and then is composed of two exponential functions. The obtained statistical shift ${\gamma}$$\_$F/ was about 8.65${\times}$10$\^$-3/eV/K and the pre-exponential factor $\sigma$$\_$0/ was about 2$\Omega$$\^$-1/cm$\^$-1/. A temperature dependent defect density is numerically calculated from the conductivity data. A change of the defect density is observed in the factor of about two in the range of the experimental temperature.

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