• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.121-123
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• 2002

Fast response characteristics of twisted nematic liquid crystal display (TN-LCD) cell with different nematic liquid crystals (NLCs) and cell gap on a rubbed polyimide (PI) surface were studied. High transmittance and fast response time of the TN-LCD on the rubbed PI surface were achieved by using high birefringence ($\Delta$ n) and low cell gap. It is considered that the transmittance and response time of the TN-LCD on the rubbed PI surface decreased as $\Delta$ nd decrease.

• 한국가스학회:학술대회논문집
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• 2000.09a
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• pp.118-123
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• 2000

• 한국가스학회:학술대회논문집
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• 2000.09a
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• pp.124-129
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• 2000

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.923-932
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• 2009

Generally most of pile foundations are constructed with group pile rather than single pile. The study on efficiency and bearing capacity which are major elements for rational design of this group pile has been actively progressed, whereas there are truly only a few studies of negative skin friction working on group pile due to the consolidation of ground. The purpose of this study is to determine, among the elements of negative skin friction applied to pile, the occurrence modality of negative skin friction at center, side, and corner of $3{\times}3$ group pile using model test and, based on those observations, to propose the effective design direction of group pile.

• Journal of Ocean Engineering and Technology
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• v.25 no.6
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• pp.1-8
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• 2011

This paper describes a new method for a digital gas metal arc welding (GMAW) system. The GMAW system is an arc welding process that incorporates the GMAW power source (PS-GMAW) with a wire feed unit (WFU). The PS-GMAW requires an electric power of constant voltage. A constant magnitude is maintained for the arc current by controlling the wire-feed speed of the WFU. A mathematical model is derived, and a self-tuning fuzzy proportional-integral-derivative (PID) controller is designed and applied to control the welding current. The electrode wire feeding mechanism with this controller is driven by a DC motor, which can compensate for both the molten part of the electrode and undesirable fluctuations in the arc length during the welding process. By accurately maintaining the output welding current and welding voltage at constant values during the welding process, excellent welding results can be obtained. Simulation and experimental results are shown to prove the effectiveness of the proposed controller.

• Proceedings of the Korean Fiber Society Conference
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• 1991.06b
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• pp.17-17
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• 1991

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.585-589
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• 2008

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.349-349
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• 2003

• Proceedings of the Korean Fiber Society Conference
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• 1989.06a
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• pp.14-14
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• 1989

• 한국전산유체공학회:학술대회논문집
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• 2008.08a
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• pp.31.5-32
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• 2008