• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.181-193
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• 2004

A life cycle cost analysis model for public water supply systems should be different from the ones for other civil and architectural facilities as the operation and the maintenance cost of the water supply systems mainly come from the various mechanical systems and the pipeline systems of the collecting/treating/distributing facilities. This paper presents a cost classification scheme and a probabilistic life cycle cost analysis (PLCCA) model for public water supply systems. A value analysis (VA) procedure that is well suited for practical purposes is also presented. The presented probabilistic life cycle model and the value analysis procedure were applied to a real world project, and this case study is discussed in the paper. The model and the procedure presented in this study can greatly contribute to the value-oriented design alternative selection, the estimation of the maintenance cost, and the allocation of budget for water supply system construction projects.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.881-895
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• 2011

Seoul Metro railway facilities' inspection and maintenance tasks cause failure analysis, but if there is trouble the diverse cause investigation and the systematic analysis and management among broken facilities, related facilities and components fell short and the conditions are different. And, excess and insufficiency, under inspection and maintenance, is being raised regardless of the introduction year and the operating environment including the number of use by applying the same facilities in the uniform inspection cycle. In this study, we will analysis systematically facility system information, failures, operational status, performance, fault and maintenance information resulting from the maintenance management of railway facilities and derive the relationship between associated equipment and its components. In addition, optimizing the inspection and the maintenance cycles of railway facilities, we will improve the reliability of operation. Considering the probability of risk, it is possible to predict the occurrence of accidents or faults and to minimize the frequency of breakdown by pre-inspection maintenance. Finally, This paper is to introduce the content of constructing the Seoul Metro RCM-based failure analysis system for railway facilities to support the optimal continuance of operation status of equipments and the securement of the safe operation of vehicles.

• Nuclear Engineering and Technology
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• v.46 no.6
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• pp.737-752
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• 2014

As condition-based maintenance (CBM) has risen as a new trend, there has been an active movement to apply information technology for effective implementation of CBM in power plants. This motivation is widespread in operations and maintenance, including monitoring, diagnosis, prognosis, and decision-making on asset management. Thermal efficiency analysis in nuclear power plants (NPPs) is a longstanding concern being updated with new methodologies in an advanced IT environment. It is also a prominent way to differentiate competitiveness in terms of operations and maintenance costs. Although thermal performance tests implemented using industrial codes and standards can provide officially trustworthy results, they are essentially resource-consuming and maybe even a hind-sighted technique rather than a foresighted one, considering their periodicity. Therefore, if more accurate performance monitoring can be achieved using advanced data analysis techniques, we can expect more optimized operations and maintenance. This paper proposes a framework and describes associated methodologies for in-situ thermal performance analysis, which differs from conventional performance monitoring. The methodologies are effective for monitoring, diagnosis, and prognosis in pursuit of CBM. Our enabling techniques cover the intelligent removal of random and systematic errors, deviation detection between a best condition and a currently measured condition, degradation diagnosis using a structured knowledge base, and prognosis for decision-making about maintenance tasks. We also discuss how our new methods can be incorporated with existing performance tests. We provide guidance and directions for developers and end-users interested in in-situ thermal performance management, particularly in NPPs with large steam turbines.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.4
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• pp.21-26
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• 2019

The purpose of this study is to suggest a method for the efficient preventive maintenance of aircraft gas turbine engine turbine blades. For this study, the types and characteristics of gas turbine engines and its turbine blades were studied, the turbine blade defect types that caused an In-Flight Shut Down(IFSD) were analyzed, the blade failure rate according to the blade life cycle was analyzed through the Weibull distribution, one of the statistical techniques. Through these research results, it is possible to supplement the problems of the life cycle management and maintenance method of the turbine blade, and to suggest the measures to strengthen the preventive maintenance of the turbine blade. In this analysis, when total cycle of turbine blade exceeds 18,000 cycles, the failure rate is over 98%, and then the special management measures are required.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1134-1141
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• 2011

Costs have long since become a major issue in railway system analysis, attention is not limited to the acquisition costs alone, but encompasses all costs involved in the use and disposal of the systems. Concepts such as Life Cycle Cost(LCC), Costs Of Ownership(COO), or Total Ownership Cost(TOC) are more and more frequent in any document dealing with system analysis. Most of railway projects have applied this LCC Model to evaluate effectiveness of system acquisition cost. But these action of LCC model does not applied all the rest of system life cycle period due to the differences of its responsibility. This is why a study has been undertaken by the operation party to harmonize the most important aspects of the LCC model. This study focused on these and other objectives for introduction of method and needs for an action plan for maintenance actions involved relevant cost allocation.

• Structural Engineering and Mechanics
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• v.31 no.1
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• pp.11-24
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• 2009

In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both ice-resistant and economical offshore platforms. However, risk is involved in the design, construction, utilization, maintenance of offshore platforms as uncertain events may occur within the life-cycle of a platform under the extreme ice load. In this study, the optimum design model of the expected life-cycle cost for ice-resistant platforms based on cost-effectiveness criterion is proposed. Multiple performance demands of the structure, facilities and crew members, associated with the failure assessment criteria and evaluation functions of costs of construction, consequences of structural failure modes including damage, revenue loss, death and injury as well as discounting cost over time are considered. An efficient approximate method of the global reliability analysis for the offshore platforms is provided, which converts the implicit nonlinear performance function in the conventional reliability analysis to linear explicit one. The proposed life-cycle optimum design formula are applied to a typical ice-resistant platform in Bohai Bay, and the results demonstrate that the life-cycle cost-effective optimum design model is more rational compared to the conventional design.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.54-59
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• 2008

The poor maintenance and management of HVAC systems finally lead to the shortening of the life expectancy and result in the increase of operating costs and energy consumptions due to low efficiencies. Also, it is essential to try to develop ways to adequately maintain and to use the building facilities efficiently in order to preserve earth environment and the limited resource. In this study, an analysis on the maintenance and management cost for HVAC systems was carried out with the capacity of equipment. Besides, the LCC(Life Cycle Cost) based analysis was carried out to verify the effect of the doing maintenance and management. As the results, the case of the good maintenance and management is able to save LCC to 11 % than the case of the poor method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.101-106
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• 2009

In order to build an effective management system for structures and to propose national policy and vision for advance of safety and maintenance management, 'Fundamental Scheme of Safety and Maintenance Management for Structures' has been established and promoted. As developed countries adopt preventive maintenance management, which is preventive as well as aggressive repair/strengthening for structures, it is needed to introduce life-cycle analysis method for improvement of economical efficiency. Therefore, this paper presents not only analysis of domestic conditions and problems related to system for safety and maintenance management, policies and costs for structures but an improvement plan.

• Construction Engineering and Management
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• v.12 no.5
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• pp.43-54
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• 2011

LCC(Life Cycle Cost) analysis on design process has to be performed for a selection of reasonable and economical design alternatives in highway construction projects. To be performed of LCC analysis, the maintenance data such that are maintenance periods, rate of repair, maintenance cost, and so on are required. Therefore the Hi-Portal System had been developed and the maintenance data has been accumulating in the Korean Expressway Corporation. However, the data are not effectively used because the system have no consideration for LCC concept, and currently, th data are acquired by survey with experts. In the study, it is proposed that the concept of Generally Annual Maintenance are practically and easily used to perform LCC analysis. Some of generally annual maintenance data are suggested through Hi-portal data analysis due to the proposed concept and LCC analysis of a real highway construction project is preformed by comparison with a current approach. From the results, it make sure that the proposed concept are effectively used to preform LCC analysis until during exactly practical data from Hi-Portal system are obtained.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.110-121
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• 2016

In the decision-making, such as selection of structure, construction method, or time and scheme of maintenance, the evaluation of life-cycle cost(LCC) is of great importance. The maintenance cost occupy a large portion of the LCC of the railway track as well as the initial construction cost. Futhermore, the proportion of the maintenance cost is much higher in the ballasted track. Thus, the importance of the LCC evaluation is higher than in any other engineering structures. In this study, a LCC model that can consider various design parameters such as the type of track structure, annual traffic volume, axle load, train speed, and proportion of curve sections and engineering structures has been developed. Fundamental data for calculating costs also have been presented. Based on the model and data proposed, the trends in the variation of LCC according to the design parameters were examined and the most important design parameters in the LCC analysis of railway track were investigated. The results show that the proportion of renewal and operational costs is much higher in the ballasted track than in the concrete track, and the annual traffic volume and ballast taming period are most significant factors on the LCC of the ballasted track. On the contrary, it is revealed that the proportion of the initial construction costs in the concrete track is much higher, and the LCC of the concrete track is less sensitive to the traffic volume, train speed, and axle load.