• 대한안전경영과학회지
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• 제19권3호
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• pp.89-95
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• 2017

This paper presents another maintenance policy for a group of units under finite operating horizon. A group of identical units are subject to random failures. Group maintenances are performed to all units together at specified intervals, and the failed units during operation are remained idle until the next group maintenance set-up. Unlike the traditional assumption of infinite operating horizon, we adopt the assumption of the finite operating horizon which reflect the rapid industrial advance and short life cycle of modern times. The units are under operation until the end of the operating horizon. Further, the operation of units are extended to the first group maintenance time after the end of the horizon. The total cost under the proposed maintenance policy is derived. The optimal group maintenance interval and the expected number of group maintenances during the horizon are found. It is shown that the proposed policy is better than the classical group maintenance policy in terms of total cost over the operating horizon. Numerical examples are presented for illustrations.

• 한국신뢰성학회지:신뢰성응용연구
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• 제18권2호
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• pp.184-191
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• 2018

Purpose: The purpose of this study is to propose a method to calculate the optimal preventive maintenance cycle of radar used in the aviation weapon system of ROKAF. Methods: A hybrid model is used to estimate the optimal preventive maintenance cycle in a system that can perform condition based predictive maintenance (CBPM) through continuous diagnosis. The failure data of the radars operating in the military were used to calculate the reliability. Results: According to the research results, the reliability threshold of the radar began to decrease after 5 flights, and decreased rapidly after 12 flights. Since the second check, costs have continued to decline. Conclusion: A method is proposed to determine the cycle of optimal preventive maintenance of radar within operational budget through modeling results between reliability limit and cost for radar. The results can be used to determine the optimal preventive maintenance cycle and frequency of various avionics equipment.

• 한국신뢰성학회지:신뢰성응용연구
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• 제18권2호
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• pp.104-113
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• 2018

Purpose: This paper proposes the non-periodic preventive maintenance policy based on the level of cumulative hazard intensity. We aim to construct a cost-effectiveness on the proposed model with relaxing the constraint on reliability. Methods: We use the level of cumulative hazard intensity as a condition variable, instead of reliability. Such a level of cumulative hazard intensity can derive the reliability which decreases as the frequency of preventive maintenance action increases. We also model the imperfect preventive maintenance action using the proportional age setback model. Conclusion: We provide a numerical example to illustrate the proposed model. We also analyze how the parameters of our model affect the optimal preventive maintenance policy. The results show that as long as high reliability is guaranteed, the inefficient preventive maintenance action is performed reducing the system operation time. Moreover, the optimal value of the proposed model is sensitive to changes in preventive maintenance cost and replacement cost.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.670-673
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• 2008

본 연구는 시설물의 2D 건설도면과 공간 DB 갱신기술을 활용하여 시설물 유지관리의 체계적이고 효율적으로 수행하기 위한 방안 제시를 목적으로 한다. 기존의 유지관리 시스템 운영 및 업무 수행시에는 시설물 건설도면 정보의 활용이 미비한 실정이다. 또, 시설물 관리주체에서 운영 중인 유지관리 시스템 조사 분석을 통해 시설물 유지 보수에 대한 이력과 유지관리 시 얻어진 시설물 건설도면 정보의 DB 갱신의 관리가 체계적으로 수행되지 않는 문제점과 시설물 내 외부 위치정보의 부재에 대한 유지관리 업무의 효율성 저하 등에 대한 문제점을 도출하였다. 이를 바탕으로 기존의 시설물 2D 건설도면과 공간 DB 갱신 기술을 활용한 유지관리 이력 및 정보의 체계적인 관리와 시설물 위치정보 제공을 통한 효율적인 업무 수행을 위한 방안을 제시한다.

• 한국주거학회:학술대회논문집
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• 한국주거학회 1994년도 학술발표대회논문집 상
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• pp.37-44
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• 1994

The purpose of this research is to present necessity of manament system establishment and policy direction for fundmental data, understanding management reality and problem, comparing resident's management attitude to related variables in apartment and raw houses multi-family houses. The major finding were as follows : 1) The management attitude of Apartment inhabitant is very highm especially the attitude of maintenance management is the higest. But they disagree with the raise of management cost necessary to maintenance management. 2) The management attitude of Raw multi-family houses inhbitant is especially high, the maintenance management demand for safety and community-life contol attitude, resident's mutual cooperation is especially high, they think much of autonomy management, desire to achieve under more sysemnatic plan.

• 경영과학
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• 제28권1호
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• pp.107-116
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• 2011

The automated teller machine (ATM) is developed as a system to provide customers with an easy deposit and withdrawal of their money without time restriction and be served for 24 hours. Today, ATM is come up to the level of an unmanned branch. The automatic financing system is developed as an essential one for dealing with the rationalization of management and the globalization of financing in order to improve the efficiency of financial management work and increase the customer service quality. With reducing the operational cost of financial organizations through the efficient maintenance operation of ATM and increasing the service quality through the maximization of its processing efficiency, this study is to draw the scheme to ensure the competitiveness among the finance companies. The importance of ATM is highly recognized as the utilization of ATM is increased and the processing function is extended, but ATM is quite vulnerable to the malfunction occurred during the nighttime after banking hours. The ATM maintenance is done through consignment to the specialized maintenance company. The efficient operation of ATM maintenance work is important to the satisfaction of customer using ATM in the nighttime.

• 한국건설관리학회논문집
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• 제6권5호
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• pp.78-88
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• 2005

공동주택의 비중이 점차 확대되고, 고층화되는 추세에 따라 공동주택 유지관리의 중요성이 강조되고 있다. 이러한 필요성에 의해 최근 기존 건축물의 종합성능 평가모델이 개발되었으나, 업무의 분석이 미흡한 한계가 있다 따라서 본 연구는 공동주택 유지관리 성능평가의 기반이 되는 유지관리 업무를 분석하여 성능평가 대상항목 도출을 목적으로 한다. 유지관리 성능평가 후보항목은 기존문헌과 업무체계를 분석하여 도출하였고, 학계 전문가 및 주택관리사를 대상으로 설문을 실시하여 성능평가의 용이성, 체계성을 보완하였다. 최종적으로 결정된 성능평가 대상항목은 운영적 유지관리 성능평가 항목 14개와 기술적 유지관리 성능평가 항목 15개 항목이다.

• 품질경영학회지
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• 제29권3호
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• pp.39-48
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• 2001

Preventive maintenance(PM) is an action taken on a repairable system while it is still operating, which needs to be carried out in order to keep the system at the desired level of successful operation. In this paper, we consider a Bayesian approach to determine an optimal periodic preventive maintenance policy. When the failure time is Weibull distribution with uncertain parameters, a Bayesian approach is established. Some numerical examples are presented for illustrative purpose.

• 품질경영학회지
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• 제31권1호
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• pp.142-147
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• 2003

Burn-in is a widely used method to eliminate the initial failures. Preventive maintenance policy such as block replacement with minimal repair at failure is often used in field operation. In this, paper burn-in and maintenance policy are taken into consideration at the same time. The cost of a minimal repair is assumed to be a non-decreasing function of its age. The problems of determining optimal burn-in times and optimal maintenance policy are considered.

• 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