• Journal of the Society of Disaster Information
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• v.13 no.3
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• pp.305-312
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• 2017

In our society, the advanced, advanced, and information industries have continued to grow and now live in the era of the fourth industrial revolution. As the industry develops, the load of the users has also increased so much that it is deepened by the energy shortage phenomenon and the construction of additional energy facilities is required. Therefore, energy plant construction work is being actively carried out in the coastal area. In particular, it is common to build a plant in the ground by filling the coast with soil in other regions, reflecting the fact that Korea is lacking in the country when constructing power plants, gas and petrochemical plants. Current domestic grounding designs are designed or constructed to suit only the use of grounding resistors based on the electrical equipment design technical standards. However, in the case of a plant facility constructed in the untested buried soil, when the lightning current and the abnormal current are inputted, the facility operator or the user due to the elevation of the ground potential is seriously exposed to the risk of electric shock disaster. In this paper, we analyze the ground resistivity of the landfilled soil and use a computer program (CDEGS) based on KS C IEC 61936-1, We analyze the contact voltage and stratification voltage and propose a grounding design optimized for plant installation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.57-60
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• 2001

CATV is the abbreviation for Cable Television. General CATV is a way of multi-channel sending images, voices and music including stillness image as well as characters to public receivers through electrical cable communication system. In the beginning, master antennas were people can not receive TV signal well. TV programs were received from master antennas to TVs in each house. Ground connection began by experimenting lightning with the use of a kite and it means electric appliances, communication equipments, measuring instruments and so on connecting the Earth in order to flow away overcharged electricity. There are two kinds of earth connection: Power Ground and Signal Ground. Power Ground is for preventing an electric shock and in general there's no current in the connector. However in an accident, there's a quick flow of electricity out to the Earth. Signal Ground is not only for the safety of appliances but also for the safety of equipment operation. This paper is about connection for noise and interference reduce in order to prevent wrong operation and distortion of signal in the electrical appliances which can take place in CATV.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.10
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• pp.34-40
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• 2008

In this paper, a device for safety inspection of a guard lamp with an automatic switch which has been recently employed in some local autonomous entities was developed. It is technically enhanced by installing a separate inspection box down below, which allows the inspectors can measure the leakage current, the sound function of the electric leakage breaker(ELB), the insulation resistance and the grounding resistance, on the ground. This inspection box makes the inspectors free from the electric shock by being designed to minimize the potential direct contact with the energized terminals. The deliverables of this paper are expected to contribute to carry out the inspection for the guard lamps safely and effectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.57-60
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• 2001

CATV is the abbreviation for Cable Television. General CATV is a way of multi-channel sending images, voices and music including stillness image as well as characters to public receivers through electrical cable communication system. In the beginning, master antennas were people can not receive TV signal well. TV programs were received from master antennas to TVs in each house. Ground connection began by experimenting lightning with the use of a kite and it means electric appliances, communication equipments, measuring instruments and so on connecting the Earth in order to flow away overcharged electricity. There are two kinds of earth connection: Power Ground and Signal Ground. Power Ground is for preventing an electric shock and in general there's no current in the connector. However in an accident, there's a quick flow of electricity out to the Earth. Signal Ground is not only for the safety of appliances but also for the safety of equipment operation. This paper is about connection for noise and interference reduce in order to prevent wrong operation and distortion of signal in the electrical appliances which can take place in CATV.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.808-811
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• 2012

매년 높은 비율의 전기안전사고가 발생하지만 예방교육은 단순한 영상홍보나 단순 텍스트를 이용한 교육 수준에서 주입식으로 이루어지고 있다. 항공, 군사, 전력산업 등 다양한 분야에서는 가상현실을 이용한 체험형 교육 시스템이 개발되어 운영되지만 전기안전 예방교육은 감전사고와 같은 특수한 상황의 체험과 사고를 유발시킬 수 있다는 측면에서 체험형 교육시스템이 개발 및 적용이 어렵다. 따라서 본 연구에서는 전기감전 체험교육 시스템에 저주파 자극 장치를 사용할 수 있도록 저주파 간섭형 자극기를 이용한 인체 자극의 임계값 산출시험을 실시하고 대표적으로 성별, 연령별(아동 및 성인 구분)로 구분하여 적절한 자극값을 산출하였다. 본 연구의 결과는 향후 전기안전사고 예방을 위한 체험형 예방 교육 시스템에 활용이 가능할 것이다.

• The Journal of the Acoustical Society of Korea
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• v.12 no.6
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• pp.53-61
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• 1993

이 논문은 접은 도체박판의 단순한 구조가 전자유도형 변환기 역할을 한다는 것을 기술하고 있다. Endoh 등은 볼록한 나선코일과 동박판으로 구성된 볼록한 방사면 모양을 한 전자유도형 변환기가 시간적으로 짧은 충격파를 발생할 수 있기 때문에 뚜렷한 초음파 영상을 얻을 목적으로 Eisenmenger에 이어 전자유도형 EMAT를 보고한 바 있다. 여기서는 코일이 없는 EMAT를 소개한다. 이것은 두께 0.05mm, 폭 5cm 길이 임의의 동박판으로 구성되며 동박판은 절연도료를 칠한 종이로 절연되고 접어서 견고하게 밀착시키며, 여러번 접는 경우는 손부채처럼 접는 방향은 교대로 반대방향으로 접는다. 그리고는 엷은 고무판을 표면에 밀착시키고 연변을 실리콘 충전제등으로 고정시키거나, polyester molding을 하여 표면을 concave형으로 하여 완성하였다. 완성된 EMAT들은 수조에서 축전기방전방식으로 실험을 하였으나 EMAT에서 발생되는 으파의 진폭은 접는 회수에 비례하였으녀, 단접형 EMAT보다 다접형 EMAT의 발생음파가 보다 강력하였다. Concave형 EMAT의 음속은 예견한 바와 같이 잘 집속되었다. 그러나 평판형의 경우는 지향성은 100도로서 넓은 지향각을 나타내었다. 2μF, 600Volt의 축전기 방전에 의한 집속형 concave EMAT를 여기시키기 위한 축전기의 용량이 작을수록 대역폭은 더욱 넓었다.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.810-818
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• 2011

This paper analyzed the suitability about the isolation performance criteria which was based on human impedance and effect of current in IEC 60479-1 on the safety of human being was examined. The method of evaluation by megger and DC voltmeter was analyzed. The differences of isolation performance according to design of high-voltage system were analyzed. The factors which affect the insulation performance were analyzed for HFCV, EV, HEV, etc. through analysis of the isolation performance evaluation method. Finally, design for improved isolation performance was proposed.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.811-813
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• 1996

High impedance fault can not be easily detected by conventional method. But if it would not be detected and cleared quickly, it can result in fires, and electric shock. In this paper, neural network, which has learning capability, is used for high impedance fault detector. The potential of the neural network approach is demonstrated by simulation using KEPCO's measured data. The instantaneous values and frequency spectrum of current are respectively used as the inputs of neural networks. Also, the methods using combined data to exploit the advantage of each data are proposed. In this paper, back-propagation network(BPN) is used for high impedance fault detector and can use for high speed relay because it detects faults within 1 cycle.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2072-2073
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• 2007

This paper describes the analysis of potential distribution and leakage current magnitude around the electrical fittings submerged in an underground shopping street. In the experiment, a couple of electrical utilities(outlet, fluorescent lamp) were submerged in a concrete water bath. The experimental results are expected to be utilized for the risk assessment and the safety countermeasure against the electric shock.

• Current Optics and Photonics
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• v.5 no.2
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• pp.121-128
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• 2021

We propose a novel, tiny optical receiver engine utilizing an all-in-one package based on embedded optics technology. The package's best transmission S21 and reflection S22 opto-electric (OE) bandwidths are 49.8 GHz and 34.9 GHz, respectively, and the reflectance of the optical engine is below -31.7 dB for all channels. The engine satisfies the MIL-STD-883G standard for reliability tests, such as mechanical and thermal shock, and vibration resistance. The sensitivity after 10 km single-mode fiber (SMF) transmission is below -8 dBm. The optical receiver engine is cost-competitive and applicable for 400G coarse wavelength division multiplexing 4 (CWDM4) 10 km optical transceivers.