• Journal of Energy Engineering
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• v.20 no.2
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• pp.154-162
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• 2011

PMT(Preventive Maintenance Template) is a standardized maintenance program that describes maintenance items & period as operation condition to increase component reliability at the component level. The existing maintenance programs are focused on time based maintenance to inspect and repair component depend on fixed period. But recently, we have developed advanced maintenance program(named PMT) to increase reliability and optimize maintenance program of the plant significant component. This paper presents how to develop the PMT for nuclear power plant's static exciter.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.6 no.1
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• pp.1-8
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• 2010

The existing maintenance program is focused on time-based maintenance to inspect and repair components according to maintenance period, rather than condition-based maintenance or predictive maintenance. The preventive maintenance template of the steam turbine has been developed for optimizing maintenance procedure and improving reliability and availability of the steam turbine of nuclear power plants based on EPRI PM template methodology and EPRI technical reports about preventive maintenance.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.459-460
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• 2015

현재의 예방정비계획 운영 방법은 KPX에서 발전 사업자들로부터 희망하는 자신들의 발전기 예방정비계획 일정을 받아서 공급예비력 기준을 만족하면 승인을 해주는 방법으로 진행되고 있다. 이는 경제적인 부분을 예방정비계획 수립에 반영하지 못하고 계통의 신뢰도 측면만을 판단하는 것으로 생각할 수 있다. 따라서 발전비용을 최소화하는 예방정비계획 최적화 모델을 적용하여 예방정비계획 수립 시 경제성을 반영하려 한다. 이를 통해 연발전비용을 낮추면서 연평균 SMP 또한 낮춤으로서 한전과 발전사업자 모두에게 이익을 가져다 줄 수 있는 것이다. 따라서 본 연구에서는 비용 최소화를 목적함수로 하는 tool을 적용한 예방정비계획 최적 값과 기존의 예방정비계획을 공급예비율, 계통한계가격(System Marginal Price, SMP), 발전비용 세 가지로 나눠 비교하고 신뢰도와 경제성을 고려한 최적 예방정비계획을 수립하였다.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.4
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• pp.108-125
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• 2014

현재 국방부는 주요 핵심 시설에 대해 EMP 방호 시설 건설 사업을 추진하고 있으며, 향후 더욱 많은 방호 시설 확보 계획을 가지고 있다. EMP 방호 시설은 장비 운용 중 방호 성능이 감소하여도 감소 현상을 알지 못하다가 EMP 공격을 받게 되면 그때 문제가 발생하게 된다. 따라서 EMP 방호 시설에 대한 정비 유지는 매우 중요하며, 방호 시설에 대한 성능 감소 여부를 평상시에도 확인할 수 있는 체계적이고, 현실적인 정비 유지 기법이 요구된다. 본 논문에서는 EMP 방호 시설 정비 유지에 필요한 정비 유지 기법을 미국 EMP 방호 시설 군사 규격 MIL-STD-188-125의 정비 유지 요구사항을 기준으로 구체적으로 작성하였으며, 실제 EMP 방호 시설 정비 유지에 쉽게 활용할 수 있도록 노력하였다. 주요 내용은 EMP 방호 시설에 대한 정비 개념, 정비 매뉴얼 구성, 정비 유지 단계(예방 정비, 고장 정비, 창 정비)의 업무, 교육/훈련 내용으로 구성되어 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.1-7
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• 2016

Although the second driving device of KTX, which consists of the wheel and the axle reduction gears unit, is a mechanically integrated structure, its preventive maintenance (PM) requires two separate intervals due to the different technical requirements. In particular, these subsystems perform attaching and detaching work simultaneously according to the maintenance directive. Therefore, to reduce the unnecessary amount of PM and high logistic availability of the train, it is important to optimize PM with regard to reliability-centered maintenance toward a cost-effective solution. In this study, fault tree analysis and reliability of the subsystems, considering the criticality of the components, were performed using the data derived from field data in maintenance. The cost optimization of the PM was derived from a genetic algorithm considering the target reliability and improvement factor. The cost optimization was derived from a maximum of the fitness function of the individual in generation. The optimal TBO of them using the genetic algorithm was 2.85x106 km, which is reduced to approximately 21% compared to the conventional method.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.163-170
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• 2011

Natural stream disasters due to a localized torrential and flash flood has occurring in a small stream especially un-implemented small stream. The survey results during ten years from 2001 to 2010 show that the small stream implementation projects (SSIPs) expenses is increasing with the damages is generally decreasing with variableness in which SSIPs is contributing to disaster prevention in a small stream. This study develop guideline for the selection of SSIPs to support high risk stream at first and save the small streams located on the mountainous area, prevention area and agricultural area which streams have no implementation effects. Developed sub items in guideline are evaluated by stream data collected from 212 small streams where it is proved that sub distance of each item are well arranged by normal distribution. This SSIPs is useful for selecting high risk small stream at first to maximize disaster risk reduction with minimum SSIPs expenses. Also, this SSIPs is used for leading to save small stream on the upstream to minimize flood damages on the down stream with selection a SSIP purchasing agricultural land for preparing flood plane.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.2059-2063
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• 2004

Most power plants have operated many independent computerize systems for maintenance. Independence of systems have caused complexity of business process and inconvenience of computer system management. Because the equipment and material master data is not standardize and structurize, it is difficult to manage equipment maintenance history and material delivery. Especially equipment classification criterion is important for standardization of every maintenance information. It is necessary to integrate function of independent systems for business process simplification and rapid work flow. this paper provides equipment classification criterion design and system integration method with the case of live system development.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.89-98
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• 2008

A preventive maintenance model, caller FNBM($\alpha$, $\delta$, $\gamma$)model, is proposed to decide an optimal repair number under achieved availability requirements(r) along with taking two types of failures (repairable or irrepairable) into account. In this model, the current system is replaced by a new one in case when it doesn't meet the achieved availability requirement, even though it is repairable failure; Otherwise it is replaced in time of the first irrepairable failure. Assumed that the j-th failure is repairable with probability ${\alpha}_j$ minimal repairs are allowed for repairable failure between replacements. Expected cost rate for preventive maintenance model is developed using NHPP(Non-Homogeneous Poisson Process) in order to determine the optimal number $n^*$, also numerical examples are shown in order to explain the proposed model. Since the proposed FNBM($\alpha$, $\delta$, $\gamma$)model includes Park FNBM model(1979) and Nakagawa FNBM(p)model(1983) this proposed model is thought to be better than previous model, especially for weapon system which requires availability as primary parameter.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.39-44
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• 2013

There have been large explosions at some chemical plants recently. Accidents in chemical plants have been caused mainly by servicing for maintenance. There is a need to find a key target for effective injury prevention in maintenance. In this paper, facilities were selected as a key target and the risk priority numbers of the facilities were calculated in order to prioritize preventative measures. The research method was based on the followings; the list of the facilities is found through injury analysis. Then, the risk of each facility was calculated by the frequency of accidents and the working day loss through injuries. In addition, the risk of the facilities was calculated again by the frequency and the severity based on knowledge and experience of experts. As a result, the facilities in chemical plant maintenance are ranked in order of high to low risk priority number; reactor, dryer, tank lorry, etc. In the future, special measures and attention should be directed according to the risk priority number during the maintenance of chemical plants.

• Journal of Korean Society of societal Security
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• v.1 no.1
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• pp.45-51
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• 2008

The purpose of this study is to suggest some effective ways to implement the regeneration projects for the zones vulnerable to natural disasters which have been delayed due to shortage of the financial resources, and thereby complete the disaster prevention projects as early as possible and thus secure the financial resources for the projects continuously. For this purpose, the researcher reviewed the statutory grounds and designation procedures or the zones vulnerable to natural disasters, and thereupon, examined and analyzed the regeneration projects being implemented in Gyeonggi-do in view of contents by zone, history of damages, annual investment plans and financial resources for investments. In addition, the researcher examined the criteria for reserve of the disaster management fund and its uses and investigated the fund sources and expenditures and thereby, addressed the problems of the statutory reserve and suggested their solutions. All in all, the researcher suggested that the disaster management fund should be invested in regeneration projects for the zones vulnerable to natural disasters in order to remove the disaster risks earlier and that the uses of the fund should be adequately deregulated with a reserve fund ceiling system to secure the financial resources for the disaster prevention projects continuously.