• 전기학회논문지
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• 제66권1호
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• pp.194-202
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• 2017

In this study, we measured and analyzed electrical noise signals present in devices and systems operated in industrial facilities. Based on the analytic findings, we studied the most effective improvement measures for eliminating such noise signals. Leakage current and ground current generate data interferences in communication systems, and therefore we measured leakage current and ground current. We also measured and analyzed electrical noises in power systems to predict noise pathways and interference routes. Furthermore, we proposed the most effective and reliable improvement measures for blocking off various noise signals and safely eliminating them by improving the internal wiring of the facilities and grounding systems. As a final step, we conducted the proposed improvement measures and confirmed that they helped to improve the operations of the device sand systems in service by re-measuring electrical noise signals and comparing them with those measured before the proposed improvement measures were implemented.

• 전기학회논문지
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• 제58권5호
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• pp.960-967
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• 2009

Power supply system of electric railway has a diversity of safety problems since it should supply high electric power to the trains moving high speed with a lot of passengers on board. This paper provides a risk assessment approach to safety management of the electric railway facilities. Construction of database from field accident information, risk assessment and management of the risk are carried out systematically to ensure the safety. The risk assessment includes hazard identification, cause analysis by FTA(Fault Tree Analysis), consequence analysis by EVA(Event Tree Analysis), and loss analysis. In terms of the severity and the probability of the accidents deduced by these analyses, the risk of the accidents is assessed by using a risk matrix designed for electric railway facilities. Based on the risk assessment, possible risk mitigation options are identified and evaluated by analyzing their impact on the risk reduction and their cost benefit ratio. The long-term safety of the electric railway facilities can be ensured by renewal of the risk assessment and the risk mitigation option analysis with continuous accident database update. The proposed approach is applied to the electric railway facilities of Korean railway based on the accident data from 2002 to 2008.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.136-144
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• 2021

Railroad Systems, which are national infrastructure industries, cause unexpected property and human damage if they fail to function while operating. Accordingly, railroad facilities supporting the railroad system are areas where high reliability and safety are required. However, it is time for systematic and scientific maintenance to be taken away from the traditional maintenance methods, as the nation's railroad facilities are now aging seriously. The purpose of this study was to secure the safety and reliability of the aging railroad communication facilities and to improve their performance. The research subjects were selected as a precision diagnosis process for railroad communication facilities, and improvement points were derived through detailed precision diagnosis process analysis. It is deemed that this study can contribute based on securing stability, improving reliability, and continuous improvement of railroad communication facilities should be conducted in the operation of the entire railroad system.

• 전기학회논문지
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• 제56권6호
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• pp.1007-1016
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• 2007

In power system, substation facilities have become too complex and larger according to an extended power system. Also, customers require the high quality of electrical power system. However, some facilities become old and often break down unexpectedly. The unexpected failure may cause a break in power system and loss of profits. Therefore it is important to prevent abrupt faults by monitoring the condition of power systems. Among the various power facilities, power transformers play an important role in the transmission and distribution systems. In this research, we develop intelligent diagnosis technique for predicting faults of power transformer by FCM(Fuzzy c-means) and Euclidean based distance measure. The proposed technique make it possible to measures the possibility and degree of aging as well as the faults occurred in transformer. To demonstrate the validity of proposed method, various experiments are performed and their results are presented.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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• pp.347-350
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• 2004

In this paper, PDA(Personal Digital Assistants) terminal is proposed to be used for controlling and managing light facilities efficiently by connecting it to a web-based server system and adding additional functions. The control box of current light facilities may be implemented based on a simple On-Off function. The operational quality of the light facilities will be efficiently improved with some practical advantages such as reduction of required facility, manpower and time in managing the lights and control boxes tv using the popular PDA.

• 전기학회논문지P
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• 제61권4호
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• pp.228-233
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• 2012

In power system, substation facilities have become too complex and larger according to an extended power system. Also, customers require the high quality of electrical power system. However, some facilities become old and often break down unexpectedly. The unexpected failure may cause a break in power system and loss of profits. Therefore it is important to prevent abrupt faults by monitoring the condition of power systems. Among the various power facilities, power transformers play an important role in the transmission and distribution systems. In this research, we develop intelligent diagnosis technique for monitoring of power transformer by FCM(Fuzzy c-means) and ELM(Extreme Learning Machine). The proposed technique make it possible to diagnosis the faults occurred in transformer. To demonstrate the validity of proposed method, various experiments are performed and their results are presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.273-275
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• 2004

Recently, many water treatment facilities are operated by automatic control or by remote control. These high technology control systems require more stable power supply than before Badly most automatic control systems adopted in water treatment facilities are non-linear load which generates electrical harmonics inevitably. This study is intended to measure and analyze the electrical harmonics occurred at the chemicals control device which is inverter application circuit. and to show the effect of the harmonics filter.

• 대한전기학회논문지:전력기술부문A
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• 제51권5호
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• pp.232-237
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• 2002

It is increased for methodology to evaluate distribution power system interruption cost in power supply zones under competitive electricity market. This paper presents algorithms to evaluate system interruption cost in distribution power supply zones taking into consideration failure rate of distribution facilities and composite customer interruption cost. In this paper, it is introduced for weighting factor for each customer failure duration and failure rate of distribution facilities to evaluate reasonable system interruption cost in distribution power supply area. Also, this Paper estimates evaluation results of system interruption cost using a sample model system. Finally, evaluation results of system interruption cost based on failure rate of distribution facilities and composite customer interruption cost are shown in detail.

• 한국전기전자재료학회논문지
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• 제23권4호
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• pp.333-337
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• 2010

This paper introduces an overall system design of a real-time monitoring system that monitors condition of urban railway AC/DC transformers, disconnecting switches, circuit breakers, regulators, and GIS (gas insulated switchgear). For effective diagnosis of urban railway facilities we developed optimized sensors and application technology. The proposed system is combined with wireless technology, implementing remote real-time monitoring of urban railway facilities. The derived real-time monitoring system for power facilities in urban railway substations will be applied not only to diagnose low voltage DC (direct current) railways but also to diagnose design of small power facilities of skyscrapers and apartments.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.844-849
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• 2006

The electric facilities for subway stations require reliable and safe electricity in spite of their load increases rapidly. Nevertheless, Korea Electrical Safety Corporation reports that the accidents of independent electric facilities increased greatly from 4,632 cases in 1998 to 6,024 in 1999 and 6,776 cases in 2000, while the ratio of the accidents related with transformers grew gradually. As it is, it is deemed very important to minimize the spreading effects of the electric system accidents and thereby, enhance reliability of the electric supply as well as its safety. According to the fact that the electric facilities for subway stations are important for the public safety and conveniences, it should be careful to set their capacity instead of simply applying the general capacity standard to them, and thereby, improve their economy as well as prevent their accidents. With such a basic conception in mind, this study is aimed at analyzing the characteristics of the electric load in the subway stations and thereupon, suggesting some guidelines for setting of the electric facility capacity for subway stations in terms of optimal operation and safety.