• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1350-1358
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• 2008

Recently the study related to life cycle cost analysis of railway structure consisted of a complex is proceeded covering several range, which is considering the methodology of efficiency and rationalization for maintenance and analysing long-time behavior of the structure of looking at standpoint from asset management and safety. But LCCA(life cycle cost analysis) of railway structure was almost impossible as there were not anything datum for maintenance plan, such as maintenance periods related to each of components(painting and corrosion of steel, and cracking of elements, etc)and maintenance proportion, despite of its 100-year history. According, for collecting data related to railway truss bridge, bridge record cards and testing safety papers, and researching question, etc are surveyed and classified for LCC Analysis. Especially, LCC assessment on the side of assets-maintenance considering about initial cost, maintenance cost, and indirect cost is constructed. Maintenance period and complementary measure rate are very important in maintenance. To decide maintenance period, Baysian updating method is applied.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.380-381
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• 2008

This paper consider the condition monitoring technology of electrical machine in metro substation need for efficient and effective management and diagnosis. Developing management system using condition monitoring system is very competitive field, and still to a great extent seen as an unnecessary cost. There are several approaches to maintenance management in urban transit such as reliability-centered maintenance, availability-target maintenance and preventive maintenance to advanced approaches involving condition monitoring techniques. In this paper we give a brief introduction to condition-based management and diagnosis in metro substation and which management system satisfying various demanding in railway.

• International Journal of Quality Innovation
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• v.7 no.3
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• pp.15-23
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• 2006

A spare ordering policy is considered for planned maintenance. Introducing the ordering, uptime, downtime, inventory costs and salvage value, we derive the expected cost effectiveness. The problem is to determine jointly the ordering time for a spare and the preventive replacement time for the operating unit which maximize the expected cost effectiveness. Some properties regarding the optimal policy are derived, and a numerical example is included to explain the proposed model.

• Journal of Applied Reliability
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• v.18 no.2
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• pp.114-121
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• 2018

Purpose: This study proposes a process for evaluating the preventive maintenance policy for a system with degradation characteristics and for calculating the appropriate preventive maintenance cycle using time- and condition-based maintenance. Methods: First, the collected data is divided into the maintenance history lifetime and degradation lifetime, and analysis datasets are extracted through preprocessing. Particle filter algorithm is used to estimate the degradation lifetime from analysis datasets and prior information is obtained using LSE. The suitability and cost of the existing preventive maintenance policy are each evaluated based on the degradation lifetime and by using a minimum repair block replacement model of time-based maintenance. Results: The process is applied to the degradation of the reverse osmosis (RO) membrane in a seawater reverse osmosis (SWRO) plant to evaluate the existing preventive maintenance policy. Conclusion: This method can be used for facilities or systems that undergo degradation, which can be evaluated in terms of cost and time. The method is expected to be used in decision-making for devising the optimal preventive maintenance policy.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.4
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• pp.1-11
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• 1996

The purpose of this study was to suggest the more efficient system for management in urban park through the investigation of the managemental condition. Research sites for managemental condition were 9 municipal park managemental offices in Seoul, Pusan and Taegu. The degree of the managemental state in these parks was generally passive and low. So, each of them had to consider the ways how to buy private-owned sites, to standardize facility maintenance, to characterize the managemental objects, to enlarge managemental personnels and systems, to apply entrusting management, to plan user-service strategies and to shorten expenditures. Particularly the positive managemental improvement in user control was demanded to cope with the changing social needs. In long term, they had to develop basic elements for the reasonable park management, clear park maps, area of facilities, the event, citizen participation, budgets and etc., and had to prepare the middle-long term management plan and the precise analysis to the managemental criteria.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.557-564
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• 2006

Life-cycle performance and maintaining cost predictions are required for the effective management for bridges. In Korea, the importance of management of bridges has been recognized over the past two decades, resulting in the development of databases and various bridge management support tools by both government and private sectors. However, none of these tools has truly included the expected features of the bridge management system (EMS) for the next generation such as the quantification of the effects of maintenance interventions on bridge condition and safety. In this paper, a novel quantification process to simulate the life-cycle performance of steel box bridges has been developed. The process is based on the Response Surface method. Various performance-related variables aloe investigated to identify a set of significant design variables to construct the response surfaces.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.44
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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.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.312-315
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• 2007

This study is aimed at developing a web-based management system of maintenance historical data, for effective maintenance performance and smooth exchange of information and communication between public facilities and public educational facilities managers. The current management state of maintenance historical data and its business process were investigated and analyzed, through interviewing with the persons in charge of managing each facility, by recognizing problems of maintenance historical data management that is able to be applied as a basis to judge facility deterioration and performance. In addition, this study suggests a maintenance historical data system of which DB may be applied to the practical business, by reflecting requests of the persons in charge of managing facilities, setting up the scope of system usage by facility, business phase and level of facility managers, and establishing a maintenance business process system.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.358-368
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• 2007

At this current, KORAIL track maintenance system has been worked with the method of corrective maintenance which is repaired some location exceeded the track management criteria as a result of track measurement. It brings about a lot of additional expenses that the corrective maintenance might be a way of missing an appropriate maintenance time, after occurring some trouble on the track due to track maintenance characteristic. We sincerely need a track maintenance system including the concept of preventive maintenance that track is corrected with predicting the trend of track irregularity. I would like to present a development direction for Korea track maintenance system having a good application in our track with analyzing TRAMS21 and RAMSYS as overseas railway company has operated a track maintenance system.

• Smart Structures and Systems
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• v.22 no.2
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• pp.151-159
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• 2018

Maintenance activities are regarded as a key part of the repairable deteriorating system because they maintain the equipment in good condition. In practice, many maintenance policies are used in engineering fields to reduce unexpected failures and slow down the deterioration of the system. However, in traditional maintenance policies, maintenance activities have often been assumed to be performed at the same time interval, which may result in higher operational costs and more system failures. Thus, this study presents two non-periodic preventive maintenance (PM) policies for repairable deteriorating systems, employing the failure rate of the system as a conditional variable. In the proposed PM models, the failure rate of the system was restored via the failure rate reduction factors after imperfect PM activities. Operational costs were also considered, which increased along with the operating time of the system and the frequency of PM activities to reflect the deterioration process of the system. A numerical example was provided to illustrate the proposed PM policy. The results showed that PM activities performed at a low failure rate threshold slowed down the degradation of the system and thus extended the system lifetime. Moreover, when the operational cost was considered in the proposed maintenance scheme, the system replacement was more cost-effective than frequent PM activities in the severely degraded system.