• Structural Engineering and Mechanics
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• v.64 no.1
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• pp.45-58
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• 2017

This paper presents the application of topology optimization as a design tool for a steel railway bridge. The choice of a steel railway bridge is dictated by the particular situation that it is suitable for topology optimization design. On the one hand, the current manufacturing techniques for steel structures (additive manufacturing techniques not included) are highly appropriate for material optimization and weight reduction to improve the overall structural efficiency, improve production efficiency, and reduce costs. On the other hand, the design of a railway bridge, especially at higher speeds, is dominated by minimizing the deformations, this being the basic principle of compliance optimization. However, a classical strategy of topology optimization considers typically only one or a very limited number of load cases, while the design of a steel railway bridge is characterized by relatively concentrated convoy loads, which may be present or absent at any location of the structure. The paper demonstrates the applicability of considering multiple load configurations during topology optimization and proves that a different and better optimal layout is obtained than the one from the classical strategy.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2005-2010
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• 2011

On AC railway systems, the neutral sections are installed in front of substations and sectioning posts in order to avoid crash between power that have differing phases. In case railway vehicles pass through these neutral sections, it is necessary for them to switch to coasting driving by notch-off. This may reduce speed of the vehicles, resulting lowered train operation efficiency. The usage of automatic power switching systems makes it possible to pass neutral sections at notch-on, enhancing operation efficiency so that it is appropriate for high-speed railway applications. This paper analyzed inrush current of main transformer that installed on the train while passing through the neutral section using the simulator.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.629-631
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• 1996

Recently, to increasing the transportation efficiency is to be a important view points in modem railway systems. Therefore the railway communication has an important meaning for the safety of train traffic. In this paper, we have proposed to use HDLC protocol for ground-to-train data transmission, which has some merits of efficiency in data transmission, reliability and bit transparency. Also we describes the HDLC application for data transmission in railway communication.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.187-192
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• 2010

Korean railway has run about 110 years since 1989 and played a great role of industrialization in Korea. It is known that rail transport systems have many advantages of being more safe, energy-efficient, and environment-friendly, as compared to other transportation systems. However, railway incidents are often attributed to the failure of safety management and critical to the efficiency of railroad industry. This study reviewed economic, financial, and general statistical information on Korea Railroad. Based on the statistical data, the effect of accidents on railroad management was analyzed. Correlation analysis revealed that railway accident had a negative effect on the gross profit of Korea Railroad. In order to reduce potential risks and incident rate, some recommendations are proposed. Actual or potential applications of this research include safety guidelines for improving efficiency of railroad industry.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1001-1006
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• 2004

Selection of optimal railway line is taken into consideration include of the purpose of railway, geographical features and facility of management. This study performed opinions of specialists, checking of industrial environment, analysis of bid guideline to select the optimal line and executed AHP method to make quality model and choose weight factors. Therefore, this study executed about six categories which are the efficiency of transportation, facility of planning and construction, economical efficiency, coincidency of planning, the civil appeal and environmental standards, connection with system, and indicated the differences of other method by analyze into specific factors of each categories.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1287-1292
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• 2010

Recently, many railway stations are built under the railway line in urban area. The passage of railway vehicles generates mechanical vibrations of a wide range of frequency. Thus, it is required to place structural vibration isolation systems to reduce vibration and noise originating from surrounding environments. This study utilizes elastometric bearings as a vibration isolation system. The slab track system on elastometric bearings is called "low vibration track" or "floating slab track." In this low vibration track system, dowel bars or plates can be installed to minimize the discontinuity of displacement between adjacent floating slab tracks. This study is to numerically investigate the effects of dowel members on static behavior of the low vibration track. The study involves two steel dowel systems including dowel bars and dowel plates. Each dowel system is analyzed under the service load condition to assess load transfer efficiency (LTE).

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.378-381
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• 2009

This paper investigates the productivity growth in Korean railway transport. The productivity growth is calculated by a process of measuring of pure efficiency change index(PECI), scale efficiency change index(SECI), and technical change index(TCI), using Data envelopment analysis (DEA) method. The data cover the period 1999$\sim$2006; 1999$\sim$2003 are the pre-structural reform years and the post-structural reform years are 2004$\sim$2006. The framework for the analysis is Malmquist Productivity Index (MPI) of the to investigate the impacts of structural reform on productivity growth, respectively. The inputs considered are the length of operating line, the number of staff, the number of coach and wagon, and the outputs are the trains movement of passenger and freight, and the traffic of passenger and freight. Results indicate that Korean railway experienced a annual productivity growth of approx. 3% after the structural reform.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1376-1382
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• 2009

Railway system is a word that includes rolling stock, railway infrastructure and signalling System in passenger transfer and rail freight. This system get higher competitiveness in energy efficiency part than other transfer system. But it is comprehensive system has latent loss of lives and property by big accident. First of all, to control this comprehensive system and to confirm safety of it, we need human resource management. This research will suggest how to apply efficiency safety verification and certification system to railway system. human resource management systems is defined as three kinds that is recruitment and management, ensure personnel's competencies and fitness, activity of assigning suitable responsible person for work.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2225-2234
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• 2011

According to Railway Safety Act, Korea Transportation Safety Authority (KOTSA) has been entrusted with 'Integrated Railway Safety Audit (IRSA) and has implemented the safety audit to the Railway operation agencies such as Korea Railway (KORAIL) and the Railway facility management organization such as the Korea Rail Network Authority (KR Network). The target of IRSA is to establish the effective rail safety management system and to raise the safety level of the Railway operation and facility agencies by checking synthetically their performance of safety duties with sincerity according to the Railway Safety Act. Even though newly introduced IRSA is conducted smoothly, it is necessary to study the methodology and criteria of the state's safety audit system. The purpose of this paper is to improve the efficiency of IRSA by the comparative research between IRSA and other similar safety audit system and to establish the consecutive improvement concept of IRSA. Second purpose is to confirm the effectiveness of IRSA by the analysis of the relationship between audit results and the safety level of the rail operation agencies.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.478-485
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• 2017

Urban DC railways have played an important role in urban transportation, and railway operation and energy management have been emphasized to be important to achieve maximum efficiency from existing infrastructure. Fast, accurate DC railway power flow analysis is required to operate a DC railway efficiently, and this paper proposes a novel methodology to analyze the DC railway power network by implementing the participation factor (PF). The PF concept consists of a correlation between the vehicle and the substation, as explained using zones based on the position of the vehicles running on the route. Then, the DC railway powerflow is calculated using the PF concept. Finally, the usability of the proposed method was validated via case studies with actual railway operation data, and we discuss some of the advantages of the suggested methodology.