• Journal of Korea Water Resources Association
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• v.43 no.7
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• pp.609-623
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• 2010

In this paper the feedback loop mechanisms that are inherent in the management of water supply systems were identified based on the system dynamics modeling methodology. As a result, a system dynamics (SD) computer simulation model that can be used to aid efficient management of water supply systems was developed. The developed SD model can be used to predict operating conditions of water supply systems including the effects of pipe maintenance on the entire system. The developed model is consisted of water supply, pipe maintenance and water supply business finance model. The operation and maintenance data from a study water supply system were used to verify the model and to predict the past and future operating conditions of the system. The policy leverage that greatly affects the operating condition was evaluated by the sensitivity analyses for the operational indices due to changes in the exogenous variables. It was found that while the pipe maintenance related exogenous variables had great effects on the leakage and conditions of pipes, they did not have great effects on the major operational indices such as revenue water ratio. It is considered that the social costs due to leaks and pipe breaks and the corresponding mechanism of propagation of the costs must be modeled to better evaluate the effects of pipe maintenance on the operational conditions of water supply systems.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.3
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• pp.123-134
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• 2017

In order to advance into the MRO industry, the Aviation maintenance organization with suitable for the standards for personnel, facilities and operations should be first approved by FAA and EASA. The purpose of study is designed to arrange the standards required for personnel, facility, operation rule for approval of Repair Station maintenance organizations certified by FAA PART 145 of the US Federal Aviation Regulation. Also to consider the following differences through the comparative analysis with domestic AMO certification of the information in the Management, Maintenance Process, and Quality System for approval of maintenance organization authorized, the additional EASA PART 145. As a comparative analysis on maintenance organization certification in the country between FAA and EASA, this study could show us that domestic maintenance organization, certified manual contents are used by applying just many of the FAA system. And we could know that as part of the EASA maintenance organization certification process, airmen personnel were relatively systematically segmented and controlled. For domestic maintenance organization certification, operational as policy implications we would like to present policy implications such as the implication of rating system of Aviation Mechanic License like EASA, the financial support of the training center to resolve the shortage of the FAA or EASA license holders, operational organization as "CAMO" for systematic aviation mechanic certified system should be required, continued construction of hangar or MRO for airworthiness repair under Governmental support, and varied application of DER system from FAA accordingly.

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.537-543
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• 2010

According to software growth, also software maintenance has been continuously improving. In addition, the existing concept of correct maintenance demands operational management and improvement of service. However, we have various limitation matters to reflect the requirements of service base for maintenance accomplishment. Therefore, we need the study of the service based process for solving such a problem. In this paper, we propose a Service based Software Maintenance Process. Proposed process based on ISO12207 standard for software development and maintenance and compares it with the service based representative standards. In a related works, we study activity of $SM^{MM}$, ITSCMM, ITIL and find out activities to be concerned with and compare it with activity of ISO 12207 and distinguish the maintenance process activity of the service base from maintenance activities. And then, we propose a service management stage. It define four activities and eight artifacts. Finally, we validate the result by comparing the proposed process with a general service operational process.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.13-19
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• 2002

In inner harbour of Inchon Port, there are two lock gates (50KT, 10KT) which have two gates per lock gate in inner/outer sides except a gate in inner harbour side 7f 10KT. Due to the lack of the fore-mentioned gate, the use of 10KT lock gate Is suspended in every 3 years for regular maintenance. Now an additional gate is under construction in order to improve the efficiency of the 10KT lock gate. This paper will be aimed to evaluate the operational utilization levels of lock gates in present and future. The present operational utilization levels of lock gates are 0.2119 in 10KT lock gate, 0.2051 in 50KT lock gate which were considered the 46.5 closed days every 3 years for 10KT regular maintenance. The levels are estimated to 0.2246(10KT), 0.2539(50KT) in 2006 and 0.2241(10KT), 0.2560(50KT) in 2011. The levels of 50KT lock gate are evaluated to be more rapidly increased up to 24.5% in 2011.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.914-919
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• 2017

While industry understands the importance of keeping equipment operational and well maintained, the importance of tracking maintenance information in reliability models is often overlooked. Prognostic models can be used to predict the failure times of critical equipment, but more often than not, these models assume that all maintenance actions are the same or do not consider maintenance at all. This study investigates the influence of integrating maintenance information on prognostic model prediction accuracy. By incorporating maintenance information to develop maintenance-dependent prognostic models, prediction accuracy was improved by more than 40% compared with traditional maintenance-independent models. This study acts as a proof of concept, showing the importance of utilizing maintenance information in modern prognostics for industrial equipment.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.4
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• pp.449-456
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• 2021

Impatience characteristics are an important factor to be considered in the defense field, which is sensitive to time, but there are not many cases applied. In addition, due to the difficulty of analysis that must consider various probabilistic factors (breakdown/maintenance distribution, impatience characteristics, etc.), military decision makers consider only simple data (number of occurrences per year, maintenance time, etc.) Therefore, in this study, a model capable of analyzing the performance of the emergency maintenance system for determining the appropriate size and organization of military and civilian maintenance personnel was presented in consideration of impatience characteristics and probabilistic factors. And through numerical analysis, the appropriate size of the military and civilian emergency maintenance teams was analyzed. This study is significant in that it can improve readiness of operational power and prevent waste of defense budget through efficient operation of the military's emergency maintenance system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.127-134
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• 2009

RAM(Reliability, Availability, Maintainability) is important performance factor to keep combat readiness and optimize operational and maintenance cost of weapon systems. This paper discusses the method to establish RAM for combat readiness by using field failure data from similarity equipments. Operational availability is estimated from a binomial distribution function of user's operational conditions such as combat readiness preservation probability, operational rate, operational availability and total number of equipment. Reliability and maintainability is estimated from field failure data from similarity equipment to accomplish operational availability. The effectiveness of established RAM is verified through analysis of combat readiness preservation probability and mission reliability. A case study of weapon system illustrates the process of the proposed method.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.5
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• pp.26-34
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• 2008

This study was conducted to investigate the correlation between golfer satisfaction and the diverse variables of golf course design and operation from the golfer's point of view. It was intended to reflect the various expectations and desires of golfers regarding golf course design and operation. The study was conducted on 119 golf courses in Korea, and 309 questionnaires were collected and analyzed. Results are summarized as follows. First, the most influential operational service variables on golfer satisfaction were "appearance of the golf courses", followed by "staff service", and "greens fee". Second, the most influential course design and maintenance factor variables on satisfaction were "course maintenance status", "teeing ground characteristics", and "landscape architecture". Third, based on the results shown in these two areas, a linear regression analysis was conducted to synthetically explain "operational service" variables and "course design and maintenance" variables. As a result, it was found that the explanation power of the synthetic model was 36.5%, and a model appropriateness test was found to be positive. As a result of a regression analysis of the synthetic model affecting golfer satisfaction, the most influential factors were "course maintenance status" followed by "landscape architecture", "tee characteristics", and "staff service". Regarding coefficient values, course maintenance status had an influence of 21.8% followed by landscape architecture at 20%, tee characteristics at 17.7%, and staff service at 15.5%. These results were found to be different from preceding studies that emphasized golf course operational service.

• 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 Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3200-3206
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• 2009

This paper describes the problem of existing maintenance system for mail sorting machnies, and presents to-be considerations of maintenance system based on AHP (Analytic Hierarchy Process) analysis with efficiency and economic aspects. There are standard procedure for diagnosis and repair of mail sorting machine as preventive and operational maintenance, roles and missions of maintenance technical support center for upgrade of maintenance skill in this paper. The proposed maintenance system will be adapted for more safety and efficiency maintenance of mail sorting machine.