• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1174-1181
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• 2011

This paper investigates the current established preventive maintenance and its corresponding data on a point machine among railway signalling facilities and suggests a part of considerable plans when the policy of the preventive maintenance is modified. It is not appropriated to apply the optimized preventive replacement period considered with the cost simply. In that case, it is suggested that the reliability should be analyzed failure mode and effects through collecting the on-site failure data sufficiently. Then, that result can be proposed to adjust the proper criteria into the rational way by comparing the initial maintenance criteria. In this paper, the alternative way to determine the feasibility of the inspection period using failure probability is introduced.

• 한국작물학회지
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• 제23권2호
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• pp.150-153
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• 1978

중의 최대수량을 올리기 위하여 필요한 최소 잡초방제기간을 추정할 목적으로 파종후 2주간격으로 10주까지 그리고 전기간육동안 제초하였을 때 중의 생육 및 수량에 미치는 영향을 조사하였으며 그 효과를 요약하면 다음과 같다. 1. 본 실험포장의 우점잡초는 피, 바랭이, 참밤동산이, 여뀌, 쇠비름 쑥, 명아주 등이었다. 2. 잡초방제기간이 길어질수록, LAI, CGR 및 주당래수는 증가되었으나 초장과 주당분지수는 차이가 없었다. 3. 파종후 2주까지만 잡초를 제거해도 콩은 경합에 의하여 새로 발하는 잡초의 생장을 억제할 수 있었으며 수량도 크게 감소되지 않았었다. 그러나 최대수량을 올리기 위해서는 최소 6주이상은 제초를 해 주어야 한다. 4. 콩의 수량과 LAI, CGR 및 주당래수간에는 유의상관을 나타내었고 수량과 초장 및 주당분지수간에는 유의상관이 없었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1179-1186
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• 2009

The high-speed train(KTX) was operated in domestic since 2004 and 4years have been passed since then. At the beginning most of the KTX component maintenance period was followed by the France SNCF. It was settled by the TBO(Time Between Overhauls). But the environment and operation condition are different form each other, so the TBO maintenance period can be different in some component. Therefore new TBO is necessary based on our own circumstances. This paper introduces failure analysis case on some components to set TBO in domestic. KTX-RCM(Reliability Centered Maintenance System), MICS(Maintenance Information Computer System) and KOVIS(KORAIL ERP System) Data was investigated.

• 한국컴퓨터정보학회논문지
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• 제22권12호
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• pp.145-153
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• 2017

Systemic management is required at each phase of the C4I system life cycle to achieve information advantage in the battlefield through stable operation of the C4I system under the NCOE. In particular, the maintenance phase is the longest period of the C4I system life cycle, and it is easy to utilize and analyze data such as faults that occur during system operation. However, according to the previous research, the maintenance is evaluated as a phase in which the definition and management of comprehensive indicators are insufficient compared to other phase. In this paper, we propose the method of C4I Maintenance Priority decision using Maintenance metric. As a result of modifying the Naval Tactical C4I System's preventive maintenance cycle according to the priority, the total number of faults is reduced and the maintenance efficiency is improved.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.158-166
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• 2007

한국철도공사는 고속철도의 운행을 계기로 선진철도 정비방법의 습득과 더불어 기존차량에 대한 검수주기 및 방법에 대한 과학적이고 체계적인 시행을 위해 철도차량 RCM적용에 관한 연구를 시행 중이다. 그 동안 철도차량의 부품과 시스템에 대한 기술의 발전이 급속히 이루어지고 있는 것에 비해 정비방법의 발전은 상대적으로 느렸다고 할 수 있다. 이에 한국철도공사에서는 부품과 시스템의 기술발전에 앞서는 정비방법의 적용은 물론이고 차량의 기술적 발전을 리드할 수 있는 정비체계를 구축하고자 노력하고 있다. 고속차량인 KTX를 제외한 기존차량은 전동차, 전기기관차, 디젤기관차, 디젤동차, 객차, 화차 등으로 구분하여 운행되고 있다. 그 중 객차, 화차를 포함한 기존차종에 현행 시행되고 있는 검수 주기 및 방법을 분석하여 개선방향을 찾아 최적의 차량정비 주기 및 방법을 적용하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.84-86
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• 2005

The digital systems such as PLC or DCS have been applied to non-safety systems of nuclear power plants because of many difficulties in using analog systems. Nowadays, digital systems have been applied to safety systems of the plants such as reactor protection system. One of the main advantages of digital systems is applicability of automatic testing methods to the systems. The protection system requires high-reliability and high-availability because it shall minimize the propagation of abnormal or accident conditions of nuclear power plants. The calculation of reliability and availability of systems depends on the maintenance period of the system. In general, the maintenance period of the protection system is one-month in case of the manual test. However, the cycle of test can be shortened in several hours by using automatic periodic testing. The reliability and availability of the system is better when test period is shortened because the reliability and availability is inverse proportion to the test period. In this research, we developed the automatic periodic testing method for KNICS Reactor Protection System, which can test the system automatically without an operator or a tester. The automatic testing contained all functions of reaction protection systems from analog-to-digital conversion function of the bistable Processor to the coincident trip function of the coincident processor. By applying the automatic periodic testing to reaction system, the maintenance cost can be cut down and the reliability can be increased.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.618-619
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• 2015

The costs due to the maintenance and its method of national road have increased every year, and the maintenance costs have become higher due to the maintenance method without considering the characteristics of each region. This study is a preliminary study regarding the determination of maintenance method according to the characteristics of each region by applying variables (e.g. serviced time, traffic volume, average temperature, maximum temperature, minimum temperature, rainfall, and snowfall) to decide the maintenance and its method through the correlation analysis of road maintenance and repair period for each regional agency using the maintenance history data of national road management agency.

• 한국경영과학회지
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• 제3권2호
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• pp.91-93
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• 1978

A methodology which can be employed to obtain an optimal preventive maintenance policy that maximizes the total machine running time over the specified working period is proposed. A system considered is comprised of m machines and r

• International Journal of Reliability and Applications
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• 제12권1호
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• pp.41-48
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• 2011

This paper considers the maintenance model suggested by Jung and Park (2010) to adopt the Bayesian approach and obtain an optimal replacement policy following the expiration of NFRRW. As the criteria to determine the optimal maintenance period, we use the expected cost during the life cycle of the system. When the failure times are assumed to follow a Weibull distribution with unknown parameters, we propose an optimal maintenance policy based on the Bayesian approach. Also, we describe the revision of uncertainty about parameters in the light of data observed. Some numerical examples are presented for illustrative purpose.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1627-1633
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• 2004

Safety and punctuality in the subway are considered as critical factors. This system is composed of many factors like signals, rails, electrical power sources, rolling stocks. The effective inspection should be carried out at all the times for the safety and punctuality. Purpose of the rolling stocks maintenance is to offer the optimum condition of vehicles, and minimize the maintenance expenses. This paper suggests appropriate maintenance period of rolling stocks to enhance the utility efficiency in SMSC.