• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.9
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• pp.493-499
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• 2003

This paper presents exact Autotransformers(ATs)-fed AC electric Railroad system modeling using constant current mode for locomotives. An AC electric railroad system is rapidly changing single-phase load, and at a feeding substation, 3-phase electric power is transferred to paired directional single-phase electric power. As the train moves along a section of line between two adjacent ATs. The proposed AC electric railroad system modeling method considers the line self-impedances and mutual-impedances. The constant current mode model objectives are to calculate the catenary and rail voltages with the loop equation. When there are more than one train in the AC electric railroad system, the principle of superposition applies and the only difference between the system analyses for one train. Filially, this paper shows the general equation of an AC electric railroad system, and that equation has no relation with trains number, trains position, and feeding distance.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.679-686
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• 2013

The reduction unit is one of the most important components in railway cars, due to the transmission of torque from the motor to the wheels. Faulty reduction gears in high-speed trains result from excessive wear on the gear or damage to the gear. These types of gear defects have a significant effect on high-speed rail operation and safety; thus, a diagnosis system for the reduction unit is needed. Vibration diagnosis technology is one of the most effective diagnostics. In this paper, the vibration parameters of a reduction unit were evaluated during a driving-gear test and a full-vehicle test, using kurtosis and the crest factor. These tests were performed under normal operating conditions; a specimen tester was used to diagnose problems in defective gears.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.10
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• pp.1051-1059
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• 2013

In general, lateral ride comfort of railway vehicle is mainly influenced by a secondary suspension placed between the bogie and carbody. Higher operating speeds of train results in increased vibration of carbody, which has a negative impact related to the ride comfort. To solve this problem, researches to replace the conventional passive suspension with (semi)active technology in the secondary suspension of a railway vehicle have been carried out. The semi-active suspension using the magneto-rheological damper is relatively simpler system and has advantage in maintenance compared to the hydraulic type semi-active damper. This study was performed to reduce lateral vibration acceleration of carbody related to ride comfort of railway vehicles with a semi-active suspension system. The numerical analysis was conducted by replacing passive lateral damper with semi-active MR damper, and robust control with the MR damper was applied to the 1/5 scaled railway vehicle model.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1689-1693
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• 2003

Communication based train control system is applied regularly worldwide. And this system may be used in domestic soon. Communication based train control system does not depend on conventional track circuit. Therefore, position and distance control of train to prevent collision with leading train may become important safety factor. This paper developed collision avoidance algorithm to control trains of several units efficiently for this. In developing a collision avoidance algorithm, it is desirable to avoid the need for additional system. Additional system restricts the development of the algorithm by limiting the effectiveness of the algorithm to only those areas where the additional system can be afforded and has been installed.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2557-2562
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• 2011

The purpose of Overall Railroad Safety Audit(ORSA) is to prevent railroad accidents, and, every two years, to inspect and evaluate whether or not railroad operators faithfully adhere to railroad safety guidelines in accordance with the Railroad Safety Law. However despite of the many contributions of ORSA, due to lots of railroad accidents such as train failures and derailment caused track irregularity this year, it has been recently considered that ORSA will be renewed into Safety Certificates System as a complement. In order to guarantee railroad safety, new Safety Certificates must included appropriate safety standards considering current our country's railroad conditions. Therefore, in this study we're going to compare safety components of foreign audit system with those of Airlines field, based on ORSA's contents for years, to review Safety Management System and Safety Culture, as a result, we'd like to suggest to updated Railway Safety Standards.

• Journal of the Korean Professional Engineers Association
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• v.34 no.1
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• pp.27-34
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• 2001

On 16Dec. 1999, It was 100 years since the opening the first railroad section of 33.2km on Sep. 1899, Korea High Speed Railroad had a successful trial run of 200km/h on test track section. And the test speed 300km/h was achieved an 28 June 2000 during continuous commissioning. In the 21st century, the High Speed Railroad will be opened commercially in Korea and will contribute to technical development. Now, it is necessary to re-evaluate the role of railroad in modern society and to activate the railroad system. Ultimately, the competitive power of nation will be strengthened with energy saving, reduction of pollution and transportation cost. It conclusion the railroad system have to be expaned about 50% of total transportation to make preparations for reopening of Eurasia silk route through KyungEu railroad connection.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.650-657
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• 2007

Since the railroad accidents due to the human error occupy considerable proportion among the railroad accidents, it is necessary to study the propriety of the physical examination system for the railroad workers. Our government is promoting some systematic supplementation for railroad safety on the basis of the Railroad Safety Act. In this paper, we perform a comparative analysis of domestic and foreign physical examination systems for railroad workers. We also compare the physical examination system for public officials with that for railroad workers. Then we consult expert opinions of the Korean Society of Occupational and Environmental Medicine. Through the comparative analysis, we provide useful information that is needed to amend the physical examination system.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.191-198
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• 2001

Present status of railroad slopes through the field investigation in 26 selected slopes and/or rockfall at risk was grasped. From the evaluation of field data, main characteristics of railroad slopes are that 1) the possibility of failure by rockfall is high, 2) the Possibility of failure by slope itself is low and 3) rockfall's risk at the in and out part of tunnel is especially high. To maintain the railroad slopes systematically and reasonably, it is necessary to make and to use the database of slopes information along the railroad. Furthermore, through the construction of basic slopes' information, maintenance system of railroad slopes was developed in connection with IR-DiPS(Intelligent Railroad - Disaster Prevention System) in the future.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.196-200
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• 2003

To fulfill the railroad station's duties efficiently, it is essential to view passenger transfer system within the railroad station and in the vicinity of railroad station in the context of broader technological developments in easy access to railroad station. To do the direct service to local station or easy transfer to other mass transportation modes, necessary courses for local govemments and each transportation agency involvement should be taken and long-term integrated transfer strategy must be found. The research designed here was designed to derive a general overview of the integrated transfer patterns with an emphasis on passenger intermodal transportation system.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.33-40
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• 2009

The Railroad Safety Act was implemented in 2005 due to the increased concerns regarding railroad safety since the Daegu subway fire in 2003. In line with this, the Act became a standard to build the total railroad safety systems which has been overlooked compared to the quantitative growth of the railroad business. The minister of the ministry of Land, Transportation and Maritime Affairs lays down the Act for railroad Companies to conduct emergency programs in response to the emergency occurring on the railroad such as fire, explosion, derailment, etc. By enacting the Safety Act, the nation's construction of the contingency management system for railroad emergency increased", and it made the railroad company prepare the Emergency SOP by establishing 'The guideline on the Establishment of the railroad Emergency Plan' in order to support the efficiency of the Act. In line with this, I would like to analyze a matter of system development and the main function of the "railroad Emergency Training Program" for activation improvement of standardized operation procedure developed through the 'Total capitalize Safety Technology development'.