• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1366-1372
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• 2011

Life cycle of the rolling stock is normally 20 to 40 years, though there is some difference in accordance with each vehicle. Maintenance cost is over the twice of purchasing price. and also it is true that precise statics is not managed properly except for some developed countries due to the difference of maintenance method, skills. After KORAIL introduced ERP system in 2007, maintenance cost is managed by type of cars, by unit. but, afterwards it should be controlled as an index and also more precisely. it is the best pending issues to make train maintenance efficiency, to utilize accumulated indexes. I want to attribute to train maintenance efficiency by analysing what is the problems in the present maintenance method.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1494-1500
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• 2008

Life cycle of the rolling stock is normally 20 to 40 years, though there is some difference in accordance with each vehicle. Maintenance cost is over the twice of purchasing price. and also it is true that precise statics is not managed properly except for some developed countries due to the difference of maintenance method, skills. After KORAIL introduced ERP system in 2007, maintenance cost is managed by type of cars, by unit. but, afterwards it should be controlled as an index and also more precisely. it is the best pending issues to make train maintenance efficiency, to utilize accumulated indexes. I want to attribute to train maintenance efficiency by analysing what is the problems in the present maintenance method.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.2
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• pp.41-48
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• 2018

Carbonation is one of the major detrimental factors to the reinforced concrete structures owing to penetration of atmospheric CO2 through the micro pores, thereby it reduces the durability of the concrete. The maintenance periods and cost for concrete according to the coefficient variation of different finishing materials is documented in literature. However, it is required to carry out the systematic and well planned studies. Therefore, keeping them in mind, surface repair was carried out to the carbonated concrete and the maintenance cost was calculated to measure the durability life after repair with different variable. The deterministic and probabilistic methods were applied for durability and repair cost of the concrete. In the existing deterministic model, the cost of repair materials increases significantly when the concrete structure reaches its service life. In present study using a stochastic model, the maintenance period and cost was evaluated. According to obtained results, there was no significant difference in the number of maintenance of the coefficient variation. The initial durability has a great influence on the maintenance time and cost of the structure. Unlike the deterministic model, the probabilistic cost estimating model reduces the number of maintenance to the target service life expectancy.

• The Journal of Society for e-Business Studies
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• v.16 no.4
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• pp.109-123
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• 2011

The maintenance prices in information security industry between Korean companies and foreign companies have been a big difference. Korea Information Security SW maintenance standards were not adequate for the rate, and there was disagreement between domestic companies and governments. This research, therefore, surveyed a standard of information SW and the status of maintenance payment rates. The study suggests an estimation method and verifies the method and an appropriate maintenance cost rate. According to the results of the study, the current maintenance cost should be increased or decreased independent with a kind of information security systems. Based on the study, Korea government is able to change the maintenance policy in information security. And the domestic companies get a theoretical ground for improving the rates of maintenance costs in information security systems and are able to allot the resources effectively.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.61-76
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• 2009

The purpose of this study are to investigate the reasonable maintenance expense of golf course according to the size and management system of each golf course. The maintenance cost per hole per golfer of 29 golf courses and the maintenance cost for items and locations of 8 golf courses were analyzed. 1. As golfers per hole increased, maintenance cost per hole per golfer decreased. 2. The decisive cost factors for maintenance cost of golf course are the number of annual golfers, the total course size, the management system, and automation of course facilities. 3. Maintenance cost of golf courses contained the landscaping areas except for building and parking lots is $869^{\}/_{m^2}$ Korean won. 4. Average maintenance cost of 8 golf courses is $44,325,000^{\}/_{hole}$. 5. Labor cost marked the largest portion in the total cost. Among the items of labor cost, repair cost for green ball mark was the highest with the ratio of 26%(\4,163,000). 6. Material cost for Fairways which reaches 30% of the total area was composed of $22%{\sim}44%$ of the total cost of materials. Cost of imported fertilizers, pestcides for insects and diseases, and sands for top dressing was the highest. 7. Material cost for Green which reaches 2% of the total area was composed of $28%{\sim}36%$ of the total cost. Cost of imported products such as particle-shaped fertilizers, micro mineral fertilizers, and soil conditioners was the highest. 8. There is no difference in cost between chemical fertilizers and the environmentally friendly fertilizers even if environmentally friendly fertilizers using microorganism or chitosan materials are also expensive.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.1
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• pp.45-50
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• 2021

Machines and facilities are physically or chemically degenerated by continuous usage. The representative type of the degeneration is the wearing of tools, which results in the process mean shift. According to the increasing wear level, non-conforming products cost and quality loss cost are increasing simultaneously. Therefore, a preventive maintenance is necessary at some point. The problem of determining the maintenance period (or wear limit) which minimizes the total cost is called the 'process mean shift problem'. The total cost includes three items: maintenance cost (or adjustment cost), non-conforming cost due to the non-conforming products, and quality loss cost due to the difference between the process target value and the product characteristic value among the conforming products. In this study, we set the production volume as a decreasing function rather than a constant. Also we treat the process variance as a function to the increasing wear rather than a constant. To the quality loss function, we adopted the Cpm+, which is the left and right asymmetric process capability index based on the process target value. These can more reflect the production site. In this study, we presented a more extensive maintenance model compared to previous studies, by integrating the items mentioned above. The objective equation of this model is the total cost per unit wear. The determining variables are the wear limit and the initial process setting position that minimize the objective equation.

• Journal of the Korea Institute of Building Construction
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• v.12 no.4
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• pp.386-392
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• 2012

In this study, life cycle cost (LCC) is analyzed according to insulation panel system type using a deterministic LCC analysis method. Through this analysis, it was found that the construction cost in the deterministic LCC analysis for Ceramic panels was low compared to the construction cost for metal and stone panels. Also, the difference in cost between the Ceramic panel and the metal panel was about 2 times. In the area of maintenance cost, it was found to be similar to the previously analyzed construction cost, in which the metal panel has the highest cost due to the high cost of construction and the frequent need for maintenance. In the case of the stone panel, a small difference in cost is shown compared with that of the Ceramic panel, but the cost is higher than the Ceramic panel. Regarding the cost of waste disposal, the Ceramic panel can reduce the cost by at least 1.5 times and up to 2 times compared to other panel systems. Finally, in the analysis of sensitivity according to changes in discount rates, the Ceramic panel and metal panel systems have a similar cost, and the cost of the metal panel is a bit larger than that of other panel systems. Thus, in the subjects used in the analysis, the Ceramic panel system shows the highest economic benefits.

• KIEAE Journal
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• v.12 no.5
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• pp.35-42
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• 2012

The rental housing has been a main role to supply a living space to the household who can not be available for the home-owner. Specially, the public rental housing is targeted for the low-income household and supplied with low rental fee. Therefore, the rent owner should manage and maintain the housing condition decently with a systematically maintenance plan which includes a repair time and scope, a repair cost. Among them, the repair time is important to make a repair plan. The repair time would be explained with two types, which is divided into a breakdown maintenance and a preventive maintenance. Each of them has a advantage in a repair cost, maintenance of the living condition and provision of the repair scope and method. In this paper, it aimed at providing the repair time in 12 components of the public rental housing which is reflected from a preventive maintenance. This study shows that overall, a permanent rental housing has a longer repair time than any other rental housing in 12 housing components. A public rental housing is closer to the a permanent rental housing then a redevelopment rental housing in repair time. On the other hand, the repair time of the 12 housing components is different form the rental housing. This leads to further study in difference of the repair time according to a tenant type.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.226-234
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• 2011

The service life of concrete structures exposed to a marine environment can be extended by controlling the amount of chloride in cover concrete. Patching is one of the appropriate maintenance techniques for chloride contamination. Chloride-contaminated cover concrete is removed and replaced with sound one. It can provide less risk of corrosion of steel, so that the structure can be maintained for required service life. In this study, a quantitative assessment of the service life subjected to the chloride attack is proposed to determine the effective repair options such as repair depth, repair material and timing of repair. The Crank-Nicolson based finite difference formulation from Fick's second law is proposed to predict the profiles of chloride ion in a repaired concrete structure, considering ingress of chloride from outer and redistribution of residual chloride from the substrate concrete. Therefore, the repair application times and maintenance cost for the target service life can be estimated. Finally, the numerical examples are presented to ensure its applicability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.19-25
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• 2016

Engineering structures including civil infrastructures require a life-cycle cost and benefit during their service lives. The service life of a structure can be extended through appropriate inspection and maintenance actions. In general, this service life extension requires more life-cycle cost and cumulative benefit. For this reason, structure managers need to make a rational decision regarding the service life management considering both the cost and benefit simultaneously. In this paper, the probabilistic decision tool to determine the optimal service life based on cost-benefit analysis is presented. This decision tool requires an estimation of the time-dependent effective cost-benefit under uncertainty to formulate the optimization problem. The effective cost-benefit is expressed by the difference between the cumulative benefit and life-cycle cost of a deteriorating structure over time. The objective of the optimization problem is maximizing the effective cost-benefit, and the associated solutions are the optimal service life and maintenance interventions. The decision tool presented in this paper can be applied to any deteriorating engineering structure.