• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.29-36
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• 2006

This paper deals with the potential interferences between grounding electrodes in various grounding electrodes. The ground potential rise and potential interference coefficients were measured by using and electrolytic tank and calculated by CDEGS program as functions of the configuration and size of grounding electrodes and the distance between grounding electrodes. The ground potential rise and potential interference coefficient strongly depend on the distance between grounding electrodes, the shape and size of grounding electrodes. The potential rise interferences between grounding grid and grounding grid is lower than those between grounding grid and ground rod.

• Electric Engineers Magazine
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• v.263 no.7
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• pp.28-35
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• 2004

접지 시스템의 계획은 접지전극 형상의 설계와 계통접지 방식에 따른 접지 시스템으로 구성하여야 하고 접지 또는 금속체간에 전위차가 발생하지 않도록 Bonding, 기술을 충분히 고려하여야 한다.<중략>

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.6
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• pp.78-84
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• 2009

This paper presents measurement results of transient impedance for small-sized ground electrodes in a discharge region of soil. For a realistic analysis of ionization characteristics near the ground electrode, three types of ground rod installed outdoors and high voltage impulse generator were used for injecting test current. From the analysis of response voltage and current flowing ground electrode to earth, it is verified that the ionization near the ground electrode contributes to reduction of ground impedance and limits the ground potential rise effectively in high resistivity soil. As a threshold electric field density for ionization is small in low resistivity soil, the shape of ground electrode rarely contributes to the transient impedance. And, from the experiment result with shape of ground electrode, the rod with needles is more effective to reduce the transient impedance than the plate electrode in the voltage range including with ionization regions of soil.

• Electric Engineers Magazine
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• v.264 no.8
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• pp.14-21
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• 2004

접지 시스템의 계획은 접지전극 형상의 설계와 계통접지 방식에 따른 접지 시스템으로 구성하여야 하고 접지 또는 급속체간 전위차가 발생하지 않도록 Bonding 기술을 충분히 고려하여야 한다. 그러나 국내의 기술기준 및 내선규정은 이에 대한 규정이 없으며 단지 접지종별 접지저항 값만을 규정하고 있어 실무에서 많은 이견이 발생하고 있고 전력기술인 협회지 2~4월호에서 살펴보았듯이 자동화 되는 생산 Line에서는 피해가 커지고 있다.<중략>

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.63-68
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• 2005

This paper describes the characteristics of effective impulse ground impedance of deeply driven ground rods combined with grounding grid or counterpoises with needles. The potential rises of the test ground electrodes were measured as a function of the rise time of applied impulse currents and the effective impulse ground impedances were calculated The impulse ground impedances of deeply driven ground rods strongly depend on the rise time of impulse currents and significantly reduced by the connection of grounding grids in parallel.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2C
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• pp.105-115
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• 2008

The records of field instrumentation, which have been performed on the pneumatic caisson used for substructure of the Youngjong Grand Bridge, were analyzed to investigate the ground contact pressure under rigid foundation of large pneumatic caisson embedded in various ground layers. During sinking the pneumatic caisson, the resisting force was mobilized against sinking the caisson at the contact area between bottom of the caisson and the ground. The resisting force could be measured by the reaction force gauges instrumented under the edge of bottom of the pneumatic caisson. And the ground contact pressure could be estimated by use of the measuring records of the resisting force. The ground contact pressure under rigid foundation of large pneumatic caisson shows concave distribution on bedrock, while convex distribution was shown in marine deposit soil layer as well as weathered rock layer. And, the ground contact pressure in various ground layers was distributed axis-symmetrically. The distribution shape of the ground contact pressure determined by the maximum pressure acting on foundation of the large pneumatic caisson showed good coincidence with the distribution shape proposed for rigid foundation by Kgler(1936) and Fang(1991).

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1566-1567
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• 2011

일반적으로 배전반과 변압기와 같은 고전압 전력기기를 운전하는 경우에는 외부 환경에 의한 열화특성뿐만 아니라 전력기기 내부의 구조적 특성에 의한 절연적 특성 변화가 발생하게 된다. 따라서 고신뢰성의 고전압 전력기기를 설계하기 위해서는 이와 같은 점을 고려한 내부 설계가 이루어져야 한다. 본 연구에서는 접지부에 여러 가지 형상을 가지는 볼트와 같은 구조물을 위치시키고 그에 따른 절연파괴전압의 변화에 대한 연구를 수행하였다. 동일한 전극 간격에 대한 AC 전압의 특성변화를 실험을 통하여 측정하고 분석하였다. 실험 결과, 절연파괴전압은 접지측에 위치한 볼트의 형상에 따라 크게 변화한다는 사실을 알 수 있었으며, 이와 같은 결과는 고전압 전력기기를 설계 및 제작하는데 큰 도움이 될 수 있을 것으로 판단된다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.705-706
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• 2012

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.601-608
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• 2006

The important elements in pavement design criteria are the stress and strain distributions. To obtain reasonable stress and strain distribution, tire contact area and tire pressures are very important. In this study, finite element analysis was used to identify the three-dimension states using nonlinear tire contact pressure and measured tire contact area. Measured tire contact area was quite different from the assumed tire contact area, and it resulted in different strain states under the tire. At the surface course, considering tire rib and nonlinear tire pressure, the pavement response presented accurate data compared to the predicted one. However, at the binder course, tire effects were generally negligible and it showed that the predicted pavement response was different compared to the measured one.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.65-70
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• 2006

This paper presents the transient behaviors of grounding system impedance against lightning impulse currents. The dynamic characteristics of the deeply driven ground rod and grounding grid subjected to the impulse current were investigated. The transient ground impedance strongly depends on the configuration and size of grounding electrodes and the shapes of impulse currents, and the inductance of grounding electrodes has a significant affect on the transient ground impedance of grounding system Also, the deeply-driven ground rod was effective to reduce the transient ground impedance in time domain of miceroseconds.