• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.5
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• pp.224-226
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• 2005

In this paper, the secular changes of buried grounding electrodes was investigated; the electrodes are such facilities as grounding grid, grounding connector, grounding terminal and grounding rod etc.. The corrosiveness of removed substation grounding electrodes after commercial operation more than 50 years was measured and its conductivity deterioration trend was analyzed. The measuring results using three experimental methods were compared, finally the consideration for safe and economic grounding design were shown. As the result, it shows the maintenance necessity of grounding systems.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.161-162
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• 2006

There are many alarms in Substation Automation System because of data types and quantities increasing, so it is very difficult for operators to know the actual situations. In order to help operators easily make decision, some unnecessary alarms should be removed or combined as one. In this paper, alarm processing is using the structure of substation system and the relation of measured data and events to make some rules. Conventional alarm processing just gives data, but proposed alarm processing gives the whole information. In a simulation model system, the data such as voltage, current and CB status are collected by HyperSim and saved in DB, then proposed alarm processing has been testified using those data based on real-time simulation.

• Journal of Pharmacopuncture
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• v.10 no.2 s.23
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• pp.47-55
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• 2007

Objectives : To verify pain relief effects and allergy inhibitory action for the osteoarthritis of the knee joint in Sweet Bee Venom in which allergy causing enzyme is removed. Methods : We randomly allocated 36 participants to treatment group Sweet Bee Venom and Bee Venom. Outcomes on pain reduction were measured by 100mm VAS(Visual Analog Scale). And we recorded into details allergic responses during Pharmacopuncture treatment. Results : Whole body condition and pain rate through VAS measurement were improved significantly in 2 weeks. We could get difference in pain score of two Pharmacopuncture groups significantly in 2 weeks. BV group showed superior reduction in pain compared to the Sweet BV group. But we could not get difference in whole score of two pharmacopuncture groups significantly. On the other hand other allergic responses such as edema, itchiness, pain were significantly lower in the Sweet BV group.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1108-1114
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• 2016

The cause of failure in the AT feeding system is divided into grounding, short-circuit of feeding circuit and internal faults of the railway substation. Since the fault current is very high, real-time current is detected and the failure must be immediately removed. In this paper, a new DC offset elimination filter that can remove component to decrease in the form of exponential function using low-pass filter was proposed in order to extract the fundamental wave from distorted fault current. In order to confirm the performance of the proposed filter method, AT feeder system was modelled by simulation tool and simulations were performed under various conditions such as fault location, fault resistance and fault voltage phase angle in case of trolley-rail short-circuit fault. When applying the proposed DC-offset removal method, it can be seen that the phase delay and gain error did not appear.