• Proceedings of the KSR Conference
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• 2003.05a
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• pp.656-662
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• 2003

The rolling-stocks used in conventional line have suffered wheel problems due to lack of adaptability with track. These brought out severe wheel wear and inefficiency of wheel maintenance. Especially, tight wheel maintenance criteria have caused waste factors of wheel machining, these increases rolling-stock maintenance costs. Thus, this study was started to Propose the wheel maintenance plans to improve maintenance efficiency in respect to wheel maintenance process in rolling-stock workshop. Here, we describe some results

• Journal of the military operations research society of Korea
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• v.26 no.1
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• pp.70-88
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• 2000

In this research we consider a statistical model to estimate the optimal maintenance manpower of aircraft which we use at present. We design a multiple regression model, apply to three types of aircraft to estimate the optimal maintenance manpower of aircraft. This paper provides reasonable results about maintenance manpower of aircraft, and contributes accomplishment of mission for air and air support operations.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.35
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• pp.115-122
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• 1995

This paper is developed with software system for the construction of periodic maintenance. The system includes records of equipment, maintenance work, failure mode analysis and work standards of maintenability, inspection & repair to establish periodic maintenance system. And the software program is designed with user-oriented to analyze maintenance data and maintenance system of periodic interval times. Also machine operator can easily apply maintenance management system in production & manufacturing field. Visual Basic in the environment of Window system is used as computer program language for graphics and data base management in IBM PC.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1612-1617
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• 2011

Rolling stock needs many maintenance works because of its long service life. The maintenance of rolling stock has periodic preventive maintenance system. This periodic preventive maintenance system can't reflect the characteristics of every part. The condition-based maintenance system which reflects the functional condition of every part prevents breakdown and reduces maintenance cost. This study will analyze the records of every part by unreasonable examples of time-based preventive maintenance and reliability management activities, and discuss the necessity of maintenance system reflected the results.

• Journal of Korean Society for Quality Management
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• v.33 no.3
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• pp.114-125
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• 2005

Maintenance equipments, tools, manuals and documents are needed to maintain the weapon systems. At the time, a lot of technical materials are maintained and used individually at a various places and organizations. Thus, maintenance engineers can not get the necessary informations quickly and the efficiency of maintenance was low. In this paper, first we analyze the maintenance processes in weapon systems and define the total measure to evaluate the maintenance efficiency of weapon systems. Second, we propose a implementation procedure to integrated maintenance system.

• Korean Management Science Review
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• v.23 no.2
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• pp.137-159
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• 2006

Maintenance equipments, tools, manuals and documents are needed to maintain weapon systems. At the time, a lot of technical materials are maintained and used individually at various places and organizations. Thus, maintenance engineers can rot get the necessary informations quickly and the efficiency of maintenance is low. In this paper, first we analyze maintenance processes in weapon systems and define the total measure to evaluate the maintenance efficiency of weapon systems. Second, we propose an implementation procedure to integrated maintenance system.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.1
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• pp.1-7
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• 2015

The aircraft maintenance demands a lot of aviation mechanics in urgent according to the high season and low season in seasonal demand adjusted, unplanned maintenance work such as AD (airworthiness directives) and troubleshooting of aircraft system fault. The advent of Super-Large Aircraft such as A380 with aircraft materials, power plant and avionics systems which were not in previous models must be expected to increase the complexity of the aircraft maintenance system. This study is intended to propose the development plan for formation of positive flexibility culture in aircraft maintenance organization through the review of previous research on flexibility culture of organization and through empirical research for bureaucratic and poor factors by the evaluation of flexibility culture level of domestic aircraft maintenance organization.

• Journal of Applied Reliability
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• v.15 no.1
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• pp.6-11
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• 2015

Maintenance plays an important role in keeping product availability, reliability and quality at an appropriate level. In this paper, two-types of maintenance policies are studied following the expiration of two-dimensional (2D) free replacement warranty. Both the fixed-maintenance-period policy and the variable-maintenance-period policy are based on a specified region of the warranty defined in terms of age and usage where all failures are minimally repaired. An accelerating failure time (AFT) model is used to allow for the effect of usage rate on product degradation. The maintenance model that arises following the expiration of 2D warranty is discussed. The expected cost rates per unit time from the user's point of view are formulated and the optimal maintenance policies are determined to minimize the expected cost rate to the user. Finally numerical examples are given to illustrate the optimal maintenance polices.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.328-333
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• 2007

Traditional maintenance planning is based on a constant maintenance interval for equipment life. In order to consider economic aspect for tm based preventive maintenance, preventive maintenance is desirable to be scheduled by RCM(Reliability-Centered Maintenance) evaluation. The main objective of RCM is to reduce the maintenance cost, by focusing on the most important functions of the system and avoiding or removing maintenance actions that are not strictly necessary. So, Markov state model is utilized considering stochastic state in RCM In this paper, a Markov state model much can be used for scheduling and optimization of maintenance is presented. The deterioration process of system condition is modeled by the stepwise Markov model in detail. Also, because the system is not continuously monitored, the inspection is considered. In case study, simulation results about RCM will be shown using the real historical data of combustion turbine generating unit in Korean power systems.

• Journal of the Korean Institute of Educational Facilities
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• v.19 no.5
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• pp.21-28
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• 2012

Current maintenance costs of the educational facilities have been determined by the years of services according to their foundation year. However, these maintenance costs have not considered maintenance and repairing. Therefore, this study suggests a new method to recalculate the years of services of schools by using the data of maintenance and repairing which is stored in the CAD drawing of the educational facilities. Also, since the data of maintenance and repairing has to be kept only for 5 years, the data is limited for the BTL project which has a maintenance period of 20 years. Thus, this study developed a new model to expand 5 years' data to the period of 20 years. This proposed model is expected to contribute in the maintenance and repairing of the BTL project.