• 한국신뢰성학회지:신뢰성응용연구
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• 제11권4호
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• pp.433-445
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• 2011

Duty cycle is determined as the ratio of operating time to total time. Duty cycle in reliability prediction is one of the significant factors to be considered. In duty cycle application, non-operating time failure rate has been easily ignored even though the failure rate in non-operating period has not been proved to be small enough. Ignorance of non-operating time failure rate can result in over-estimated system reliability calculation. Furthermore, utilization of duty cycle in reliability prediction has not been evaluated in its effectiveness. In order to address these problems, two reliability models, such as MIL-HDBK-217F and RIAC-HDBK-217Plus, were used to analyze non-operating time failure rate. This research has proved that applying duty cycle in 217F model is not reasonable by the quantitative comparison and analysis.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년 춘계학술발표대회 논문집
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• pp.344-349
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• 2009

To be Low Carbon and Green Growth, it is necessary that Long-Life Housing based on Green Technology is supplied. The main concern at the moment is developing Sustainable Housing relative to Life-Cycle or Life-Style of the residents, and the resident of Remodeling or Redevelopment. This study is aim to be Development of Maintenance Process in order to make steady dwelling when supplying Long-Life Housing that separates Support(Skeleton) and Infill different from the existing Short-Life Housing, and has durability, alterability, available remodeling, easy maintenance. Long-Life Housing should consider the maintenance about movement and variableness. In contrast, the maintenance of the existing Housing is regular maintenance, change and repair by damage. As well as Long-Life Housing should be demanded proper Development of Maintenance Process because of difference of Housing in concept, design and Construction. Therefore, this study looks into problems when applying Development of Maintenance Process in Long-Life Housing, and shows Development of Maintenance Process about the efficient Long-Life Housing for the manager.

• 한국철도학회논문집
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• 제14권3호
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• pp.216-221
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• 2011

수리 가능한 시스템의 신뢰성 분석에 중요한 문제 중의 하나는 유지보수 효과를 모델링하는 것이다. 현재까지 많은 연구들은 유지보수 후 시스템의 상태가 새것과 같이 된다는 완전유지보수 또는 유지보수 바로 직전의 상태로 된다는 최소유지보수 모형을 사용하였다. 그러나 국내운영기관에서 시행하는 유지보수 형태는 완전유지보수와 최소유지보수의 사이의 효과를 가지는 불완전유지보수 형태로 시행하는 경우가 많다. 본 연구에서는 이와 같이 불완전 유지보수가 수행되는 전동차의 장치들 중에서 승객용 도어시스템(PDS:passenger door system)의 고장데이터를 분석하고 유지보수 효과 수준을 적용하여 불완전유지보수 주기를 결정하는 문제를 다루었다.

• 산업경영시스템학회지
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• 제20권44호
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• pp.123-128
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• 1997

A data base design framework for predictive a preventive-maintenance system is presented in this paper in order to effectively control machines and reduce accident rates in the workplace. The data base is designed to meet general management requirements to evaluate different maintenance strategies. There are seven data files: the equipment list maintenace pesonnel, maintenance history, maintenance specification, spare part, maintenance equipment, and maintenance schedules. Each data base file has several record based upon data acquisition.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1202-1207
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• 2011

This article introduces the benchmarking methodologies, the results of comparative analysis on the railway electricity maintenance management - preventive maintenance, corrective maintenance, upgrade maintenance. This article also compares the Korean railway electricity maintenance management with the results mentioned above and analyses the situations of each country - France, Germany, Japan. Lastly this article tries to find the comparative position of the Korean railway infrastructure costs and discusses the direction of cost reduction in railway electricity maintenance management.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권2호
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• pp.57-66
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• 2012

In this paper, we consider the periodic preventive maintenance model for a repairable system following the expiration of replacement-repair warranty. Under this preventive maintenance model, we derive the expressions for the expected cycle length, the expected total cost and the expected cost rate per unit time. Also, we determine the optimal preventive maintenance period and the optimal preventive maintenance number by minimizing the expected cost rate per unit time. Finally, the optimal periodic preventive maintenance policy is given for Weibull distribution case.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.157.3-157
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• 2001

In this paper, the optimal maintenance scheduling for turbine with considering maintenance replacement rate was proposed in order to reduce the maintenance cost during the whole period of operation, meanwhile keeping current reliability of turbine. The proposed method is only based on a few limited available data with various factors relating to maintenance replacement and repair of turbine. The proposed method will be adopted by Kyushu Electric Power Co., Inc. from April in 2002 to determine the maintenance schedule of thermal power plants.

• 한국국방경영분석학회지
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• 제15권1호
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• pp.54-62
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• 1989

This paper presents a corrective maintenance model to determine either type of maintenance actions upon failure of the system. Types of maintenance actions considered are minimal repair and replacement. Minimal repair cost is assumed to be random, whereas replacement cost is fixed. A policy, B(t), which determines the type of maintenance action based on the estimated minimal repair cost when the system fails at time t is adopted. To obtain an optimal policy, an expected maintenance cost per unit time is derived and is minimized with respect to B(t).

• 산업경영시스템학회지
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• 제22권52호
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• pp.171-180
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• 1999

Industrial equipment reliability improvement and maintenance is gaining attention as the next great opportunity for manufacturing productivity improvement. Reactive maintenance is expensive because of extensive unplanned downtime and damage to machinery. To avoid such an unplanned machine downtime, it is needed to use proactive maintenance approach by either using historical maintenance data or by sensing machine conditions. This paper discusses failure diagonosis and prediction based on the condition-based maintenance and reliability technique. Thus, by enabling such a framework, it can bring us more efficient planning and execution of maintenance to reduce costs and/or increase profits.

• 산업경영시스템학회지
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• 제21권45호
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• pp.247-251
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• 1998

From the early 90's TPM(Total Productive Maintenance) plays important roles to improve productivity and quality to keep enterprise's competivity. This study presents the results of an enquiry for the maintenance management of Korean industry in 1996. The response rate was 35.8% (43 companies) that the corporations were divided into four industrial groups, heavy process, light process, heavy assembly and light assembly. 40 question were asked, including maintenance organization, maintenance personnel, maintenance cost, measurement of maintenance performance and improvements achieved. This paper compares the results with those of an earlier Japanese and British enquiry.