• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1523-1529
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• 2018

Electric vehicles that are currently in operation are being produced domestically. Therefore, there is no great difficulty in receiving or repairing the failed parts or in the overall repair. On the other hand, most of the electric locomotives are manufactured by introducing the parts and technology of foreign vehicle manufacturers. In this paper, conducted a study about life cycle cost analysis of developed auxiliary power unit in 8200 series electric locomotive and suggested cost down method. This confirms the economic benefits of the developed products of the auxiliary power supply compared to the existing products. In addition, a sensitivity analysis of MTBF was conducted to suggest a life cycle cost down method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.426-430
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• 2008

Though the air-conditioners in each train model have almost identical function, there is incompatibility between them because of their different electric capacity and parts, even spares manufactures are different in the manufactured year. It cause over cost in the maintenance and repair of the each air-conditioner. In this paper, all the air-conditioners in each train model have been classified by their capacity and features so that grasp the operation status and the repair process of the air-conditioners, and draft systematically cost-effective solutions. By finding a way to deal with the emergency repair and extending the air-conditioner life though improvement of checking up progress, increase of passenger revenue can be reached considerably.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.350-353
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• 2004

The integral reactor is tripped by the boron injection to the reactor when the CEA(Control element assembly) is not available due to its malfunction. In general, the borated water is made by dissolving the boron powder in the water and is stored in a tank. and then injected. But, this method is disadvantageous from the view point of construction cost, operation and maintenance because it has many components and is complicated. In this study, the boron powder direct vessel injection method is adopted to improve the system. Injecting the boron powder directly to the vessel and decreasing of number of components, the system configuration, operation and maintenance is simplified and the construction cost is reduced.

• Journal of Appropriate Technology
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• v.5 no.1
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• pp.8-17
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• 2019

Solar pumps, for water lift systems, is becoming popular in rural areas for supplying drinking water in dry seasons when its need is elevated. The development in technology has also made solar pumps readily available and cheap which has increased its demands. So, for scattered settlements having a limited budget for operation and maintenance costs, solar pump is preferred over grid connected electrical pumping systems. This primary objective of the study was to design a solar photovoltaic pumping drinking water supply system for a small health post which is about 45 km east from Kathmandu, the capital city of Nepal. The study also compared and verified the final design with the system's existing design prepared by a development agency. The water source for this study was a confined aquifer 115m below the surface. The water demand was calculated to be 11m³ per day. A 1500 kPa submersible pump attached to a motor was selected and installed. Along with that twelve solar panels, reservoir, transmission main and distribution main was designed. The outcomes conclude solar photovoltaic pumping water supply systems to be cost-effective with an estimated cost of only USD 0.84 million per MLD. Solar pumps require low maintenance and operation costs and its repairs can quickly be done by the local people. The study also shows that solar technology produces no sound, needs no fuel making it environmentally friendly.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.575-583
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• 2011

In order to minimize the maintenance cost at local lines, Information & Communication Technology based onboard train control system is being developed. Unlike the central traffic control based fixed block system, this system use a moving block method and railway driver direct control switch and railway crossing. The purpose of this paper is to analyze the concerned main operational issues are as follows: the preparation of train operation, drivability, the role of driver and controller, block system and cost. We defined the role of driver and driver's input data for train service, and we designed the business process of driver using UML tool. We considered the aspect of drivability, DMI is needed to support the braking moment for the driver and driver training simulator. We designed the driver business process for control of switch and railway crossing. We analyzed the fixed block system and moving block system to confirm the difference with the existing operational method. The cost analysis structure is also needed for the operation cost comparison.

• Plant Journal
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• v.11 no.2
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• pp.45-51
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• 2015

In this paper, studied condenser operating management which is affecting power plants efficiency considering the cost of poor quality. Sea water temperature and condenser pressure have clear correlation in S power plants. As the sea water temperature changes, condenser pressure changed -1.7~+20 mmHg from design condenser pressure(38.1 mmHg). Use the heat rate correction curve from manufactory company, realized that efficiency and cost of poor quality changed 0.0201%, 12,830 won/h at Unit #1,2 but 0.0155%, 9,832 won/h when condenser pressure 1 mmHg rise. Also, checked that it is changed depend on seasonal corresponding operation, plant ageing and the point of preventive maintenance like overhaul maintenance. This study said if we considered complying with management range and planning overhaul maintenance, then it could help reducing operating maintenance losses minimum 2.5 billion won per 1 year (case : Unit #1, forty days maintenance).

• 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 for Quality Management
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• v.18 no.2
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• pp.33-42
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• 1990

This paper proposes the maintenance model of multi-component system when the failure characteristics and types of components are considered. In this model, it is assumed that a system is composed of a critical component, a major component and a minor component. Also, failure types is classified into major failure and minor failure. If major failure occurs to critical component before system age replacement time, the system is renewed. If major failure does not occur until its age replacement time, preventive maintenance is performed at age replacement time T. Minimal repairs are carried out after each minor failure. Major component is minimal-repaired if any failure is discovered during operation. Minor component should be replaced as soon as any failure is found. This paper determines the optimal replacement time of the system which minimizes total maintenance cost. Numerical example illustrates these results.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.26 no.2
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• pp.1-8
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• 2003

The operation and management of a plant require proper accounting for the constraints coming from reliability requirements as well as from budget and resource considerations. Most of the mathematical methods to decide the inspection time interval for plant maintenance by reliability theory are too complicated to be solved. Moreover, the mathematical and theoretical models are not usually cases in the practical applications. In order to overcome these problems, we propose a new the decision-making method of optimal inspection interval to minimize the maintenance cost by reliability theory and genetic algorithm (GA). The most merit of the proposed method is to decide the inspection interval for a plant machine of which failure rate $\lambda$(t) conforms to any probability distribution. Therefore, this method is more practical. The efficiency of the proposed method is verified by comparing the results obtained by GA-based method with the inspection model haying regular time interval.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.24 no.3
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• pp.10-18
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• 2016

This paper deals with the Performance Based Logistics(PBL) application scheme pertaining to optimal maintenance program for logistics of Korean Fighter Experimental(KF-X) Project. For enhancement of the performance based logistics system application to KF-X program the selection of appropriate standards fit to maximize cost-cutting, a set of performance metrics fit for the purpose of the contract, foreign technology dependence of core equipments and parts were considered. Thus, selecting appropriate standards fit for Korean logistics environment, domestic maintenance enterprise for stable rate of operation of KF-X, a systematic reliability task that is able to measure quantitative combat capability are suggested.