• Title/Summary/Keyword: 코받침

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Analysis of force exerted on the nose by the spectacles weight (안경의 무게에 의해 코에 작용하는 힘 해석)

  • Kim, Dae-Soo
    • Journal of Korean Ophthalmic Optics Society
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    • v.10 no.4
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    • pp.273-281
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    • 2005
  • The weight of spectacles fined on is resolved into its components along the nose's slide plane and the normal to the nose plane where the nosepad is located. The equation and its numerical solution to determine the component force was derived as a function of splay angle ${\Psi}$, $sin{\Psi}$, $cos{\Psi}$, and $cot{\Psi}$, incorporated with ${\theta}$ and ${\Phi}$, the angles viewed from side and front of the face, respectively. Values of inclination angle ${\theta}$ and ${\Phi}$ could be obtained to fulfill the condition where the frictional force between the nose and pad is either greater than the normal pressure exerted by the spectacles on the nose. With the value of ${\theta}$ fixed the normal pressure increases as ${\Phi}$ increases. With ${\Phi}$ fixed, the effect of ${\theta}$ is the same.

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Modifications of RC/TS(Resonant Column and Torsional Shear) Device for the Large Strain (대변형율 시험을 위한 공진주 비틂전단 시험기의 수정)

  • Bae, Yoon-Shin
    • International Journal of Highway Engineering
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    • v.10 no.3
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    • pp.1-10
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    • 2008
  • Conventional RC/TS(resonant column and torsional shear) device usesa specimen with an aspect ratio(height-to-diameter) of 2:1 and this generates a maximum shear strain in the sample of about 1.5% at the maximum rotation of the drives system. The objective of this study is to modify RC/TS device to generate higher strain amplitude. The modifications include a new base pedestal to overcome the limitations in the travel of the drive system and modification of coil wiring to increase torque. The effects of the new coil wire on torque in the electro magnetic drive system were evaluated and the application of modified device was illustrated using sand soil.

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