• Journal of Korean Society for Quality Management
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• v.31 no.1
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• pp.142-147
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• 2003

Burn-in is a widely used method to eliminate the initial failures. Preventive maintenance policy such as block replacement with minimal repair at failure is often used in field operation. In this, paper burn-in and maintenance policy are taken into consideration at the same time. The cost of a minimal repair is assumed to be a non-decreasing function of its age. The problems of determining optimal burn-in times and optimal maintenance policy are considered.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.153-162
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• 2017

Weapon systems have been developed with high technology electronic equipment due to technology growth. In addition, the capital, operational and maintenance costs of weapon systems have all increased. However, cost of operation and maintenance for weapon systems has been decreased relatively compared to the increased capital cost of weapon systems. Therefore, the defense industry needs to research the life cycle cost of weapon systems that have high operational and maintenance costs. This paper focuses on maintenance equipment for the operation and maintenance of weapon systems. Recently, it seems that the weapon systems that have periodic calibration with maintenance equipment are valid. The equipment requires periodic calibration by the manufacturer to check its own validation. Basically, customers demand high reliability devices from foreign companies that have qualified in the global market. Therefore, the tools need to be calibrated overseas. In other words, weapon systems are not available when the equipment has to be calibrated overseas because the systems require validation with valid maintenance equipment. A purpose of this paper is to compare the loss costs that arise from the calibration of the equipment overseas and the purchasing cost of the tools. Finally, the research shows the number of equipment that customers need to minimize the cost. This research will help to improve the efficiency of operation of weapon systems and solve the problems associated with the need for maintenance overseas.

• Journal of the Korean Society for Railway
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• v.10 no.3 s.40
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• pp.327-336
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• 2007

Operation a subway company requires high amount of early construction, operation and maintenance costs. Seoul Metro, one of the public subway companies in Seoul, Korea, has undergone operational deficit from its establishment, and the main reason is that the early construction and operation cost exceed the total revenue. Therefore, detailed researches on current operation system and possible alternatives are conducted to settle down finance trouble of the company. In particular, problems on operation and ticketing systems are analyzed, and based on that, necessity and detailed plan of railroad pass for one day are introduced and analyzed.

• Korean Journal of Construction Engineering and Management
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• v.23 no.3
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• pp.83-94
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• 2022

The number of public rental housing has increased according to the government's 「Housing Welfare Roadmap (2017)」, and facility maintenance costs for the demand of improvement of performance and residential standards due to the aging of long-term public housing are significantly increasing. Consequently, the financial burden of public housing rental business for maintaining stocked housing is aggravated. However, there is a lack of objective data to analyze the size of the maintenance costs that are executed by the type of repair work, and the elapsed years of the aged long-term public rental housing. This study analyzes the execution status of 33 long-term public rental housing complexes located in Seoul for 14 to 28 years of elapsed years based on the data of maintenance costs. In addition, this study proposes a model to predict the maintenance costs by elapsed years by dividing 'Long-term Repair Plan Work and Government-Funded Project [Y₁]', 'Planned Repair Work and General & Unplanned Repair Work [Y₂]', and 'Total maintenance costs [Y₃]'. It is intended to be used as basic data for the establishment of the maintenance plan at the stage of setting up the budget and the establishment of the sustainable operation plan for public rental housing

• Proceedings of the Korean Statistical Society Conference
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• 2002.11a
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• pp.147-151
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• 2002

Burn-in is a widely used method to eliminate initial failures. Preventive maintenance policy such as block replacement with minimal repair at failure is often used in field operation. In this paper burn-in and maintenance policy are taken into consideration at the same time. The cost of a minimal repair is assumed to be a non-decreasing function of its age. The problems of determining optimal burn-in times and optimal maintenance policy are considered.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.899-904
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• 2007

Improvement projects has been progressed for railway electrification and double track line in the conventional line as well as high speed line for the high speed and large transportation capability of railway. Especially, many variable operation plans are possible such as interaction between high speed line and conventional line and operation of tilting train due to the electrification of the conventional line. Railway electrification is more energy efficient and environmentally-friendly, but it has some problems such as an enormous initial construction and maintenance costs and electrical accidents. Therefore, the more intensive research will be progressed about railway electrification effectiveness for the continuous electrification project. So, we analyzed railway electrification effectiveness about the energy side using annual operation data of electric car and diesel car. The energy side was divided into energy costs and national energy consumption for analyzing electrification effectiveness about entire line and specific line. We verified advantage of energy costs and national energy consumption in this paper and this result will contribute to the progress of the continuous electrification project and the more efficient operation ways in electrification line

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.3-11
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• 2013

Recently according to increasement of the single family and dual-earner couples, the number of infants and young children stays on a long time to the childcare facilities. this is increasing the importance to improve the physical environment. However, the operating and maintenance costs of the national-public childcare facilities have taken effect of the unfair support issues of municipality's financial situation. Especially, because of the lack of the operating and maintenance costs of the facility and the shortage of facilities equipment maintenance repair costs, nursery operations and Maintenance items are needed to distribute appropriately. Therefore, this study is to estimate the importance to facility operations and maintenance items based on "Kindergarten and Childcare Facilities"presented at the Child Care Policy Study. we are expected to allocate appropriately of operation and maintenance cost of a limited budget. In particular, those can be considered for operation and maintenance cost about the National-Public Childcare Facilities and be determined to a safe and pleasant environment to kindergartens through the appropriate operations and maintenance support.

• Journal of Korean Society of Transportation
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• v.30 no.4
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• pp.71-81
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• 2012

The Korean government has actively accepted private investments in building expressways to improve its financial status. As of 2012, 422km of 9 private expressways are under operation, and until 2016 additional 15 are planned to be built with private investments. However, on average, each private expressway is at most 37km long, which works against economies of scale in maintenance and thus leads to inefficiencies such as traffic jams, driver inconveniences, and the increase in operating costs. To resolve these problems, the present study suggested that the maintenance and tolling system should be unified across each private operator. Unifying the operation of private expressways was expected to reduce user travel times and tolls, and save operator maintenance costs. These economic effects were expected to be tantamount to hundreds of billions of dollars. The shared toll collecting system will also reduce user's delays by removing main line tollgates. This can save another hundreds of billions of dollars by ensuring driver's convenience and safety.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.148-158
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• 2011

As critical infrastructure, bridges play an indispensable role in facilitating the distribution of goods. When bridges reach their end of useful life or get damaged by natural disasters such as earthquakes or storms, they have to be removed and reconstructed. When bridges in service need to be reconstructed, user costs occur from vehicle detours and traffic congestions, and social costs occur from noise and dust during construction periods. However, these user and social costs are not considered during reconstruction and the evaluation methods of those costs are vague. Thus, there is lack of appropriate bridge types that consider these costs. Therefore, this paper identifies the social overhead costs that occur during bridge reconstruction, which is also called, users' socioeconomic values. Next, it proposes a method to evaluate user costs during bridge reconstruction, and appraises the method. User costs are evaluated based on traffic information, social and material volumes including the bridge's daily traffic volume, peak hours, detour distance and time. In addition, time delay costs due to traffic operational costs and bridge reconstruction are also taken into consideration.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.1
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• pp.70-76
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• 2012

The purpose of this study is to analyze of the operating characteristics of the Gas engine driven Heat Pump(GHP) and to reduce maintenance costs through the most Economical plan. As the zoning modifications that have economic effects were confirmed. Applications should be made with a similar purpose of the space. The combination of a modified space has led to reduced operating hours of the outdoor unit. The reduction of the outdoor unit operating hours, reducing maintenance costs accordingly. When analyzed at six years have elapsed, the amount of savings through zoning modifications is more than an additional construction cost. During the design phase, cost-effective operation of the GHP is required for the proper zoning plan.