• Proceedings of the CALSEC Conference
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• 2003.09a
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• pp.72-77
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• 2003

Visual inspection works are very important part of facility maintenance and management life cycle as a step of creating base data for decision making and maintenance and repair. But currently, visual inspection works have been performed unefficiently and unreliably as works on hand, duplication of works, decisions of defect state, unutilization of inspection history, lack of professional and so on. In this research, we developed visual inspection system that processes inspection work efficiently and provides reliability of inspection output, as a target of bridges, tunnels, underground roadway on national road. We defined problems through visual inspection work analysis, examined the solutions and reflected to functional design of system. We will plan to utilize this system in HMCS(Highway Maintenance and Construction Service).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.759-767
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• 2021

Most weapons systems that are Force Integration are expensive equipment that reflects the latest technology, and the operation and maintenance cost is increasing continuously. Factors that efficiently operate and maintain these weapon systems include maintenance plans, economic costs, and repair part requirements. Among them, predicting the repair parts requirements during the life cycle in advance is an important way to increase operation and maintenance cost efficiency and operating availability. The start of requirement analysis for repair parts is a calculation of the CSP (CSP: Concurrent Spare parts, CSP hereafter) that is distributed when the weapon system is deployed. The CSP is an essential component of achieving the operating availability during this period because the weapon system aims to successfully perform a given operation mission without resupply for an initial set period. In the present study, the CSP calculation method was analyzed, reflecting the failure rate and operating time of items, but the analyzed CSP was aimed at preparing for technical failure, but in the initial operating environment, it is limited in coping with unexpected failures caused by human error. The failure is not included in the scope of free maintenance and is a serious factor in making the weapon system inoperable during the initial operation period. To prevent the inoperable status of a weapon system, CSP that considers human error is required in the initial operating environment, and the calculation criteria and measures are proposed.

• Journal of Applied Reliability
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• v.17 no.3
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• pp.246-255
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• 2017

Purpose: This study proposes the optimal PM (preventive maintenance) policy of leased equipment for lessee's decision-making using two types of reliability condition. Methods: We consider reliability threshold based PM model. Equipment reliability is estimated and used as condition variable. The effect of repair for maintenance is imperfect and represented by age reduction factor. Results: We provide two PM policies. Policy 1 is focused on minimized total cost. This policy guarantees reliability threshold until last maintenance action. Policy 2 focus on maintaining reliability threshold during leased period. The proposed approach provides optimal reliability threshold under number of PM. Through result, we finally construct decision-making process for lessee using reliability threshold and end of reliability. Conclusion: This study provides two PM policy for lessee's decision-making. Through numerical example, we get a result of optimal reliability threshold, number of PM, optimum alternative under lessee's reliability condition.

• IE interfaces
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• v.15 no.1
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• pp.89-98
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• 2002

This paper considers the optimum replacement times of a steam generator in nuclear power plant with failure data. It is assumed that the failure pattern of units is given as a Weibull distribution and repair and periodic preventive maintenance are performed periodically. The maximum likelihood method is used to estimated the Weibull parameters of failure distribution from failure data. Relpacement, output-decresing and maintenance costs are considered to determine the optimal replacement times by simulation. Numerical examples are included with actual failure data and cost estimators.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.285-293
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• 2011

Sewage treatment facilities are growing rapidly in quantitatively and qualitatively. However, privatization such as up-size and professionalism, etc. are insufficient, compared to global companies' cases. Infrastructure Asset management has not been applied widely despite of sewage treatment facilities are one of the most critical social infrastructure. Maintenance, repair, and rehabilitation (R&R) practices of sewage treatment facilities have been studied and infrastructures asset management techniques have been applied. Cost model which makes it possible to calculate managerial costs such as major cost, etc. needs to be developed only with project basic information when proceeding new sewage treatment facility construction and management and overseas sewage project. Effects to converse major repair cost into capital, application of sewage treatment facility's asset management, expected effects, etc. were analyzed and suggested an alternative on the improvements of legal system.

• Journal of the Korea Institute of Building Construction
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• v.10 no.6
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• pp.97-107
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• 2010

This study outlines a successful and effective plan for repairing water-leakage cracks in concrete structures. The lack of adequate solutions for water-leakage cracks often results in unnecessarily high repair costs, and as such this remains a problem that requires constant attention. Unfortunately, despite the availability of a vast number of different materials and methods, it is often difficult to attain a perfect waterproof sealing The reason for the difficulties in the repair of water-leakage cracks can be attributed to an insufficient knowledge and understanding of the negative factors (i.e., chemical and physical (mechanical) conditions) that cause water-leakage cracks, and of the properties of the repair materials and methods. In this study, guidelines and methods for the selection of adequate materials for the repair of water-leakage cracks in concrete structures were developed for countries that do not already have general guidelines on this subject, and for local regulatory authorities elsewhere.

• Journal of the Korean housing association
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• v.21 no.6
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• pp.71-80
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• 2010

The purpose of this study is to classify defects of the residential building by analyzing the defect specified by prequalification of residential building reconstruction and to suggest the solution of the problem which can be arisen during each stage of plan, construction and maintenance. By sorting the main defects which is specified by pre-qualification of residential building reconstruction for three years from August 2006 to August 2009 into 4 catagories and analyzing the cause of the defects, we draw the way of maintenance to prevent the defects and make pleasant residential environment. The reason for the frequent defects from residential building is mainly deterioration. It occured on the finishing more than on the structure, which means that residents can find defects easier on the finishing than the structure and clear the demand for repair. The result of analyzing of pre-qualification of residential building reconstruction is that the defects mostly caused small, masonry constructed and lower apartment. The apartment which is not into legal right for maintenance naturally have more defects than the others. In conclusion, it is necessary to establish a law of obligation duty of the maintenance of small apartment.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.221-226
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• 2014

The purpose of this study is to suggest improvement directions and analysis of assistive technology service linkage on public benefits in local assistive technology center. The service steps and the main program parts of public benefits linkage in local assistive technology center was identified, and the present status of associated repair works and contact suppliers of assistive technology device in local community was investigated. The result showed the most common level of associated status to provide information of assistive technology devices in public benefits. All the centers provided repair service, and it was typically performed to light maintenance. The centers offered with associated professional repair service supplier for high maintenance service. The connection with assistive technology device supplier appeared a lot of regional difference. Henceforth, the centers will be required to distribute more various assistive technology devices, it is necessary upgrading the quality of information and interaction with the public benefits supporting organizations through its expansion, and it is need to ensure based on policy through the analysis of the effectiveness about linkage.

• Journal of Practical Engineering Education
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• v.8 no.2
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• pp.91-94
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• 2016

This study is focused on the development and application of automotive lighting system simulator device to help understanding of the repair and overhaul, electrical instrumentation and automotive circuit checks the contents of the automotive electrical system. The purpose of this study is to define the circuit numeracy, circuit repair preparation skills, detachable power, circuit analysis capabilities, inspection and measurement capability, and repair (problem solving) skills, through the cultivation of clean ability to increase the understanding of electrical equipment maintenance circuitry to verify the improvement of the repair. Automotive electrical device requires understanding of the invisible parts, and understanding of the various symbols and complex circuitry to measure the basic checks and repair are indispensable. This paper would likely contribute to help students to gain more interest in the fields that they feel difficult such as basic skills which necessary to cultivate a variety of electrical equipment fault diagnosis of the basic knowledge needed for electric cars practical.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.81-82
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• 2015

BIM has been a reliable construction project management tool to handle various kinds of construction information generated in the facility life cycle. To take these advantages, researchers have been promoted numerous studies in a residential, a commercial, and an educational facilities with a large number of on-going projects. However, despite running as the role of essential energy supplier, power plant related BIM research is relatively insufficient than others. In particular, due to the extending of the facility service period and the requirement of the complicated construction project management for 'overhaul' and 'repowering' in the power plant maintenance phase, the needs for using BIM have been increased gradually. For using BIM based maintenance, it is needed to consider an information collecting methods and necessary to develop an appropriate breakdown structure to share information. Therefore, 'EBS' is produced by reviewing the previous research related to BIM and analyzing the repair activities in the maintenance phase. Proposed 'EBS' must be useful not only a judgment between capital expenditure versus revenue expenditure but also appropriate maintenance strategies development for property management.