• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.525-531
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• 2006

In the port, the yard crane is very important. If a container crane or a transfer crane is broken down, it costs a lot because of the delay of work during the period of repair or reorder. But, we don't have enough spare parts because of the high cost. It is necessary to maintain high reliability of the crane through effective preventive maintenance and failure analysis. In this paper, we analyse the function and failure mechanism of the transfer crane which is a main equipment in the yard Also, we standardize failures and maintenance works using the historical data of failure and maintenance. This study which is a basic work for effective equipment operation and maintenance will support reliability engineers to decide the optimal design of the next generation equipment and operational policy of equipment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1325-1330
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• 2010

The breakdown of any critical component of a turbine results in the outage of power plants. Unexpected failure decreases equipment utilization and causes enormous economic losses. Currently, we conduct conservative preventive maintenance for a maintenance period that is proposed by a vendor. In the rapidly changing business environment, reliability-based maintenance is required in order to remain competitive and reduce maintenance costs while maintaining the reliability of equipment. In order to determine an appropriate maintenance period for guaranteeing reliability, we must determine the failure probability by carefully analyzing the failure history of the equipment. In this study, we created a database of failure history for power-plant turbines, predicted the best repair time using the Weibull function, and investigated how the appropriate maintenance cycle can be determined.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.363-366
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• 2006

In the port, Yard Crane is very important. If container crane or transfer crane broke down, it costs much money for delaying of work during the period of repair or reorder. But, we can not have enough spare parts for its high cost. It is necessary for having the reliability of crane through the effective preventive maintenance and failure analysis. In this paper, we analysed the system's function and failure mechanism of transfer crane which is main equipment in the yard. Also, we standardized the failure and maintenance work using the historical data of failure and maintenance. This study which is the basic work for IT of equipment operation and maintenance is going to be new attempt for optimal design of next generation equipment and operation policy of equipment.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.214-216
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• 2004

최근 들어 전력 공급의 신뢰성 강화를 위해 변전설비 고장을 미리 진단할 수 있는 예방진단기술이 절실히 요구되고 있으며, 한국전력공사 및 기타 수요자 층에서 예방진단기술 도입을 추진하고 있다. 또한 센서 기술과 디지털 기술, 통신 및 컴퓨터 기술의 발전과 더불어 실시 간으로 변전설비를 감시할 수 있는 온라인 예방진단이 가능하게 되었다. 이에 본 논문에서는 변전소용 온라인 예방진단 시스템을 현장에 적용한 사례를 소개 하고자 한다.

• Nuclear industry
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• v.16 no.5 s.159
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• pp.30-41
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• 1996

고리 4호기가 지난 4월 5일 국내 최장인 423일간(95. 2. 8$\~$96. 4. 5)의 한 주기 무정지 안전 운전을 달성하고 계획 예방 정비를 위해 정지했다. 이러한 쾌거는 지속적인 설비 환경 개선과 철저한 계획 예방 정비를 통해 기계고장률을 제로화하고, 각종 훈련을 통해 운전원들의 운전 능력과 비상 대응 능력을 향상시킨 결과라 할 수 있다. 국내 최장 OCTF 달성의 성과 의의와 과정을 들어본다.

• 보일러설비
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• no.2 s.145
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• pp.150-152
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• 2006

햇살이 차츰 따사로워지면 겨울 내내 소홀히 했던 자동차 점검에 관심을 가져야 한다. 겨울철에는 특별한 이상이 없는 한 점검에 게으른 경향이 있다. 겨울철 차량관리가 혹독한 환경에서 발생될 수 있는 고장이나 사고를 예방하기 위한 차원이라면 봄철관리는 상처입은 부위를 어루만져 주는 개념이다. 추운날씨로 인해 오일류가 변질됐을 가능성이 있는 데다 도로에 뿌린 염화칼슘이 차체에 달라붙어 차의 부식을 급진전시키기 때문이다. 따라서 겨울이 지난 따뜻한 봄날 대청소를 하는 기분으로 차량점검을 꼼꼼히 하자. 중고차 시장에 내놓을 경우 잘 관리한 차가 높은 가격을 받을 수 있다. 물론 철저한 관리가 사고를 예방하는 데 한몫 한다는 것도 잊지 말자.

• The Journal of Korean Association of Computer Education
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• v.3 no.2
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• pp.77-86
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• 2000

As the information technology is being rapidly developed, Korean government supplies various communication equipments to schools and therefore, it causes difficulties to cope with various faults from complicated school network communication equipments. These faults come from many reasons for wasting school budget and decreasing effectiveness in school administration. From this, it is necessary to figure out the problems of school communication equipments and cope with these problems quickly and preventing those faults in advance. In this paper, we present the school communication equipments analysis methodology not only quantitative but also qualitative aspects. We are sure that applying this methodology may improve the effectiveness of school network equipments management.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1016-1017
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• 2006

프로세스 제어기에서 전원장치의 건전성과 신뢰성은 아무리 강조해도 지나치지 않을 것이다. 본 논문은 전원장치의 고장 감시장치에 관한 것으로, 직류 전원공급 시스템의 신뢰도 향상을 위하여 사용하는 이중화 전원 구성용 블로킹다이오드의 고장 감시 장치에 관한 것이다. 이중화 전원 공급장치에 있어서 2개의 공급전원 중 어느 한쪽의 공급전원이 상실되더라도 나머지 한쪽의 공급전원이 건전하면 정상적으로 부하에 전원을 공급하게 하기 위하여 블로킹다이오드를 사용한다. 그러나 블로킹다이오드에 고장이 발생한 경우, 전원공급장치 자체는 정상이더라도 이중화 기능을 하지 못하므로, 블로킹다이오드의 정상 여부를 상시 감시하여 이상이 발생시 경보처리 한다면 예기치 않은 전원공급 중단을 피할 수 있을 것이다. 블로킹다이오드에 흐르는 전류와 다이오드의 양단 전압을 상시 감시/계측하여 정상운전특성곡선과 비교하여, 이상이 있을 경우 이를 경보하여 전원중단을 예방할 수 있는 이중화 전원용 블로킹다이오드의 고장 감시 장치에 관한 것이다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.3
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• pp.174-182
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• 2007

There are not many studies on the maintenance and replacement for the ITS equipments. Most of ITS center has no comprehensive regulation on the equipment replacement. This study was focusing on estimation of equipment replacement period and the number of spare parts in stock using the actual failure data of Road Side Equipment (RSE) by Dedicated Short Range Communication (DSRC). The failure data showed a type of bath-tub curves. The data, however, did not fit to any probability distribution curve, which means that the preventive replacement cannot be strongly applied for the RSE. In the aspect of practical strategy, this study suggest that repairing cost and failure frequency be used for decision of replacement of RSE after the 1 or 2 year warrant period. The future study needs to include more RSE failure data as well as other equipments of the ITS.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.6
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• pp.1-10
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• 2023

The nuclear power plant(NPP)'s Instrumentation and Control(I&C) system periodically conducts integrity checks for the maintenance of self-diagnostic function during normal operation. Additionally, it performs functionality and performance checks during planned preventive maintenance periods. However, there is a need for technological development to diagnose failures and prevent accidents in advance. In this paper, we studied methods for estimating the reliability function by utilizing environmental data and self-diagnostic data of the I&C equipment. To obtain failure data, we assumed probability distributions for component features of the I&C equipment and generated virtual failure data. Using this failure data, we estimated the reliability function using representative artificial intelligence(AI) models used in survival analysis(DeepSurve, DeepHit). And we also estimated the reliability function through the Cox regression model of the traditional semi-parametric method. We confirmed the feasibility through the residual lifetime calculations based on environmental and diagnostic data.