• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1864-1874
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• 2007

Korean trains pass many mountain areas, so the volume of structures like bridge and tunnel has large part of railway lines. Train speed-up naturally needs a straight line in railway, then structures are increasing, and the length of structure has more than 70% in Kyongbu high-speed railway. The stiffness of bridge and tunnel is higher than the soil in the roadbed in spite of dynamic difference in vibration and displacement. Differences in stiffness have more dynamic effects and increase the deformation and destruction in the track and roadbed. This influences passenger's comfort and the safety of operation, and it needs more track maintenance. This study selected tunnel with ballast track, tunnel with concrete track, and structure's approaches with short maintenance cycle in the roadbed and had track acceleration tests and track liner inspections using track master in the field. This study will measure periodically to structure's approaches which have very fast track irregularity and analyze dynamic differences and track irregularity near structure's approaches, so realize the cause of track irregularity of structure's approaches and use basic data for reasonably strengthening method of structure's approaches.

• Structural Monitoring and Maintenance
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• v.5 no.1
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• pp.79-92
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• 2018

The evaluation theory of reliability, availability, maintainability and safety (RAMS) as a mature theory of state evaluation in the railway engineering, can be well used to the evaluation, management, and maintenance of complicated structure like the long-span bridge structures on the high-speed railway. Taking a typical steel-truss arch bridge on the Beijing-Shanghai high-speed railway, the Nanjing Dashengguan Yangtze River Bridge, this paper developed a new method of state evaluation for the existing steel-truss arch high-speed railway bridge. The evaluation framework of serving state for the bridge structure is presented based on the RAMS theory. According to the failure-risk, safety/availability, maintenance of bridge members, the state evaluation method of each monitoring item is presented. The weights of the performance items and the monitoring items in all evaluation levels are obtained using the analytic hierarchy process. Finally, the comprehensive serving state of bridge structure is hierarchical evaluated.

• Journal of KIBIM
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• v.9 no.1
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• pp.42-51
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• 2019

Maintenance of aging structures has attracted societal attention. Maintenance of the aging structure can be efficiently performed with a digital twin. In order to maintain the structure based on the digital twin, it is required to accurately detect the damage of the structure. Meanwhile, deep learning-based damage detection approaches have shown good performance for detecting damage of structures. However, in order to develop such deep learning-based damage detection approaches, it is necessary to use a large number of data before and after damage, but there is a problem that the amount of data before and after the damage is unbalanced in reality. In order to solve this problem, this study proposed a method based on Generative adversarial network, one of Generative Model, for generating acceleration data usually used for damage detection approaches. As results, it is confirmed that the acceleration data generated by the GAN has a very similar pattern to the acceleration generated by the simulation with structural analysis software. These results show that not only the pattern of the macroscopic data but also the frequency domain of the acceleration data can be reproduced. Therefore, these findings show that the GAN model can analyze complex acceleration data on its own, and it is thought that this data can help training of the deep learning-based damage detection approaches.

• Structural Monitoring and Maintenance
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• v.5 no.2
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• pp.273-295
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• 2018

In this study, an investigation of a damage detection methodology for global condition assessment is presented. A particular emphasis is put on the utilization of wireless sensors for more practical, less time consuming, less expensive and safer monitoring and eventually maintenance purposes. Wireless sensors are deployed with a sensor roving technique to maintain a dense sensor field yet requiring fewer sensors. The time series analysis method called ARX models (Auto-Regressive models with eXogeneous input) for different sensor clusters is implemented for the exploration of artificially induced damage and their locations. The performance of the technique is verified by making use of the data sets acquired from a 4-span bridge-type steel structure in a controlled laboratory environment. In that, the free response vibration data of the structure for a specific sensor cluster is measured by both wired and wireless sensors and the acceleration output of each sensor is used as an input to ARX model to estimate the response of the reference channel of that cluster. Using both data types, the ARX based time series analysis method is shown to be effective for damage detection and localization along with the interpretations and conclusions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.288-292
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• 2013

This paper presents the result of life-cycle cost (LCC) estimation for domestic products propulsion control system (motor block unit) of KTX-1 considering periodic maintenance. Life cycle costing is one of the most effective approaches for the cost analysis of long-life systems such as the KTX-1. Life cycle costing includes the cost of concept design, development, manufacture, operation, maintenance and disposal. To estimate LCC for domestic products motor block unit, it was analyzed physical breakdown structure (PBS) on motor unit in view of maintenance cost and unit cost etc. As a results, life cycle cost on motor block unit increased moderately expect for periodical time when major parts are replaced at the same time. hereafter this results will be reflected in the domestic products being developed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.183-192
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• 2022

Function and performance degradation in tunnel structure can cause road's function loss, proactive maintenance is needed to prevent the initial damage from progressing to intensified damage. Inspection and diagnosis are implemented in accordance with regulations, but it does not fully reflect maintenance processes such as inspection and diagnosis, planning rehabilitation and carrying out. It was carried out for 5,540 cases inspection and diagnosis result in 1,728 tunnels was analyzed to suggest rational maintenance plan in this study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.4
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• pp.23-30
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• 2013

Reliability Centered Maintenance(RCM) is one of most widely used methods in the modern power system to schedule a maintenance cycle and determine the priority of inspection. A precedence study for the new structure of rearranged system should be performed due to introduction of additional installation. This paper proposes a new method to evaluate the priority of maintenance and inspection of the power system facilities. In order to calculate that risk index, it is required that the reliability block diagram should be analyzed for the power system. Additionally, a fault cause analysis is also performed through the event-tree analysis.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.448-453
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• 2003

Most urban transit companies recognize the necessity of classification for facility management Classification for urban transit facility is necessary for standardization of maintenance management. The practical application. however. is not easy because of the absence of standardization of classification for urban transit facility and the difficulty in objectification of breakdown structure. This study suggests a proposal of classification for maintenance management in urban transit facility. This study defines standardization of classification as facility, work, maintenance and attribute to manage urban transit facility. And attribute classification consist of material, equipment and document. The suggested classification can be used as a useful maintenance management tool that enables evaluation of urban transit facility by standardization. The results of this study could be used as references for related urban transit companies.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.57-64
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• 2007

RIMS（Rolling Stock Information Maintenance System)　was installed in structure which it can analyze the data base in need of credibility maintenance. So it could accumulate real data without repulsion of working spot. Information system was installed not following to system but following to working spot. The development of RIMS project was started from March 29, 2001 and it has been operating from October 12, 2004 in Chang-dong Car depot for light maintenance in charge subway line4. So substantial data base was accumulated for three years. This study calculated all RAMS data by analyzing data base accumulated in RIMS and used in dada base about credibility maintenance and found investigation of propriety, expectation of the life cycle cost, the improvement plan on credibility of sorts of cars and formation about the cycle of repairing and maintenance. This got MKBSF MKBF and MTBF about devices and sorts of line4 Rolling Stocks for it.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.143-150
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• 2007

RIMS（Rolling Stock Information Maintenance System)　was installed in structure which it can analyze the data base in need of credibility maintenance. So it could accumulate real data without repulsion of working spot. Information system was installed not following to system but following to working spot. The development of RIMS project was started from March 29, 2001 and it has been operating from October 12, 2004 in Chang-dong Car depot for light maintenance in charge subway line4. So substantial data base was accumulated for three years. This study calculated all RAMS data by analyzing data base accumulated in RIMS and used in dada base about credibility maintenance and found investigation of propriety, expectation of the life cycle cost, the improvement plan on credibility of sorts of cars and formation about the cycle of repairing and maintenance. This got MKBSF MKBF and MTBF about devices and sorts of line4 Rolling Stocks for it.