• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1082-1084
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• 1998

In this paper, we developed a diagnosis device for ZnO arrester to detect on-line leakage current and acquire data from the power distribution system. The arrester is important power equipment used in power transmission and distribution systems to protect the generator and the main transformer from surge and overvoltage. First of all we developed a diagnosis device for ZnO arrester leakage current. And then we detect the total leakage current by the developed device without disconnecting the arrester ground wire and analysis the 3rd order harmonic by Fast Fourier Transform(FFT) to diagnose the ZnO arrester deterioration. With measuring the total current and the resistive current of power distribution system in operation, we analysis the trend of resistive current component in the total leakage current. We expect the result will be promote the method to protect electrical utility and customer from accident.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1214-1219
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• 2002

Railway signalling system always is required high safety and reliability. The failure of the train control system can provoke a serious accident. In this paper, we show how to achieve the safety and reliability by dividing signalling system into vital and non functions, studying operational environment.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.229-232
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• 1988

Induced voltage causing disturbances on the communication lines of electric train is dealt with when the AT power supply system is employed. In the paper we obtain an algorithm to calculate the induced voltages on the communication lines in the AT system and an algorithm for the induced current in case of the accident that the line falls to the ground. These algorithms are developed to a package of computer programs and their validity was checked on a simulated system.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.627-628
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• 2005

22.9KV-Y 배전선로의 특고압 수전선비에 계량장치로 부설되어 운영중인 계기용변성기 M.O.F(Metering Out Fit)는 계기용변압기와 계기용변류기를 하나의 상자 속에 수납한 것으로 전력량계와 조합시켜서 전려측정의 변성장치로 사용되고 있다. 계량장치의 사용되고 있는 계기용변성기는 고객과 공정거래 확립을 위하여 상시 정해진 비오차 특성을 만족하여야 한다. 그러나 고객구내 수전설비에서 파급고장이 발생시 과전류로 인하여 계기용변성기의 권선에 큰 충격이 가해져 비오차특성에 문제점이 발생하여 이에 따른 현상으로 고찰하고자 한다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1463-1464
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• 2015

This paper describes for the diagnosis insulating oil for transformers integrity assessment. The high-capacity oil transformer has several insulators are entered for the purpose of insulation, such as insulating oil, insulating paper and press board. Irradiated with a gas component dissolved in the insulating oil can analyze the status of the transformer, and can prevent a sudden accident in advance.

• Journal of the Korean Society of Safety
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• v.4 no.1
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• pp.83-90
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• 1989

Recently, due to the increase of 220V distribution lines and equipments preventive measures to cope with several kinds of electric accidents is revealed as an urgent problem. This study investigates the following matters; the cause and present condition of e1ectric shock accident, the influence of electric shock on human body, the safety limit of electric shock, the method of distribution voltage, the insulation of electrical load apparatus, the teachnics of electric shock prevention and foreign materials concerned with this subject etc. This paper present the fundamental cause of electric shock and syntbetic preventive counter measure of electric shock, too.

• Journal of the Korean Society of Safety
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• v.21 no.5 s.77
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• pp.40-45
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• 2006

In the operation of large capacity hydro generators, it's a very important thing that to minimize several kind of electrical trouble and accident. In order to overcome these problems, the on-line and off-line partial discharge (PD) measuring method has become an important one. Nowadays, epoxy mica coupler(EMC) has been the most widely used sensors for on-line PD detection in rotating machines. This time, we have made a ceramic coupling sensor using $SrTiO_{3}$, because at present, most of sensors has high cost and difficult procedure to making. This paper deals with the electrical characteristics of a ceramic coupling sensor, which has been made to continuously measure PD activity during the operation condition for 13kV class hydro generator. And we have performed the evaluation of sensor life and reliability based on the characteristic testing. The experimental results confirm that the sensor has satisfied at electrical required performance and output characteristic for simulated input signal.

• Physical Therapy Korea
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• v.3 no.3
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• pp.32-43
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• 1996

The purpose of this case study was to introduce functional electrical stimulation(FES) for paraplegic patients. FES provides the ability to rise from sitting to standing, maintenance of a standing position, and the ability to walk with a reciprocal gait. Six channels of electrical stimulation are sufficient for synthesis of a simple reciprocal gait pattern in these patients. During the double-stance phase, knee extensor muscles of both knees are stimulated, providing sufficient support for the body. Only one knee extensor muscle group is excited during the single-stance phase. The swing phase of the contralateral lower extremity is accomplished by eliciting the synergic flexor muscle response through electrical stimulation of afferent nerves. The transition from the double-stance phase to the swing phase is controlled by two hand switches used by the therapist or built into the handles of the walking frame for using by the patient. A twenty-five years old male was with a T9/T9 spinal cord injury due to a traffic accident and admitted to Yonsei Rehabilitation Hospital for comprehensive treatment. After 30 days of training using the Parastep(R) he was able to stand for 10 minutes. After 43 days, he was able to walk and at discharged he could walk for 100 meters.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.3
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• pp.52-58
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• 2008

The importance of. identifying the causes of electrical faults cannot be overstated because of the accidents caused by over-current that take place at the home, the office and electrical facilities due to misuse, poor products and system faults. It is necessary to gather objective, scientific data pertaining to electrical fault investigation in a product liability(PL) environment. To date, no database(DB) has been built concerning the accurate cause analysis of faultyfacilities. In this paper, accident hazard and arc scattering when over-current flows in copper wire was investigated. It was found that when over-current flows in a copper wire, the copper wire became heated and bent and beads were scattered around the wire with a flash. It was determinedthat the fusing current and time was related to the current rise per second. For example, when the current rise per second was largethe fusing current was higher than when the current rise per second was small, and the beads dispersed along a wide area. Fusing time, however, was shorter. The possibility of electrical fault became highest when the fusing current was higher. As the current rise per second is short, the dendrite structure is distributed in the surface of the copper wire. These experimental results can be utilized for a fault process DB system in the investigation and the prevention of electrical faults.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.3
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• pp.677-684
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• 2018

Recently, negative emotional responses by drivers are a growing problem, which leads to not only a traffic accident but a crime so called 'road rage' in countries with heavy traffics including South Korea. Under such a circumstance, measuring stress- and fatigue-induced emotional responses by means of wireless communication and a wearable system would be useful. The purpose of this study is to implement a system that measures various signals from a driver, derives and monitors his emotional responses from the measurements and verify its derivations with reliability. This paper, as a first part of the research, describes how the system has been implemented with experimental methods.