• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.127-131
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• 2010

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds of structures used stainless steel sheets are commonly fabricated by using the gas welding. For fatigue design of gas welded joints such as fillet and plug type joint, it is necessary to obtain design information on stress distribution at the weldment as well as fatigue strength of gas welded joints. And also, the influence of the geometrical parameters of gas welded joints on stress distribution and fatigue strength must be evaluated. Thus, in this paper, ${\Delta}P-N_f$ curves were obtained by fatigue tests. Using these results, ${\Delta}P-N_f$ curves were rearranged in the. ${\Delta}{\sigma}-N_f$ relation with the hot spot stresses at the gas welded joints.

• International Journal of Railway
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• v.5 no.4
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• pp.175-181
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• 2012

This study proposes a model for railway safety assessment with which the safety of whole railway system can be evaluated. The purpose of the assessment model is to generate safety indicators which quantitatively represent the degree of railway safety. Safety indicators were proposed as three indicators according to their functions; accident indicators, safety management indicators, and safety culture indicators. This paper describes the first result on the safety target which will be a key starting point toward the development of safety assessment model. It is recommended that the safety target to be composed of several sub-targets are apportioned to constituent components. It is concluded that the classification of safety target has influence on deciding components or attributes that constitute each sub-indicators; accident indicators, safety management indicators, and safety culture indicators. Based on this study, a railway safety assessment model will be developed in the following study.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1978-1983
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• 2008

With the increase in population, the area of human activities has expanded, resulting in the dramatic increase in the need for transportation system. Various infrastructures necessary for efficient logistics, however, have not been supplied enough and the logistics efficiency in Korea is in a bad situation now. As a result of the situation, the demand for the railroad transportation system that can provide large volume transportation has increased dramatically. An electric railway system is composed of high-tech subsystems, among which main electric equipment such as motors and converter are critical components determining the performance of electric vehicle. Among the on-board equipments, traction equipment is important part that has influence on safety and performances of vehicles. We is studied for high-speed train of foreign countries. From this research, we knows that axle weight of HEMU-400x is reasonable within 13ton.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.382-387
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• 2009

Requirement management is an important phase that has a significant influence on the project success. As a risk to a project fail is getting bigger, people adopt Systems Engineering method to the development of the effective requirement management. Accordingly, Railroad Safety Technology R&D Corps. is progressing the plan of the construction of Railway Safety Test Facilities as a part of the Railway Total Safety Project to enhance the railway safety, and carrying out researches on effective requirement management methods with Systems Engineering techniques. To support that, we introduce the Systems Engineering Requirement Management Process and propose the more effectual management method of constructing the Railway Safety Test Facilities applying the model-based systems engineering tool to the research.

• Journal of Welding and Joining
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• v.28 no.3
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• pp.86-91
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• 2010

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds structures used stainless steel sheets are commonly fabricated by using the gas welding. For fatigue design of gas welded joints such as fillet and plug type joint, it is necessary to obtain design information on stress distribution at the weldment as well as fatigue strength of gas welded joints. And also, the influence of the geometrical parameters of gas welded joints on stress distribution and fatigue strength must be evaluated. the ${\Delta}P-N_f$ curves were obtained by fatigue tests. Using these results, ${\Delta}P-N_f$ curves were rearranged in the ${\Delta}{\sigma}-N_f$ relation with the maximum stress at the edge of fillet welded joint.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.35-40
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• 2002

The Korean high speed railway system is scheduled to open sometime in 2004. To fulfill its duties, it is essential to view intermodalism in easy access to high speed railway station. To study travelers' choice of mode and to make improvements the transfer, a SP survey of 3628 was conducted in national level in the fall of 2001. An understanding of KTX passenger mode choice is crucial for station-related facility capacity planning. Development of main and regional high speed stations, as well as changes in the roadway and railroad transportation system for station access, will influence the relative demand for traveling by train from compel ing other transportation mode. The research described here was designed to derive a general overview of the basic travel patterns with an emphasis on intermodal transportation system.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.29-31
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• 2006

Stainless steel sheets are widely used as the structural material for the railroad cars and the commercial vehicles. These kinds structures used stainless steel sheets are commonly fabricated by using the gas welding. For fatigue design of gas welded joints such as fillet and plug type joint, it is necessary to obtain design information on stress distribution at the weldment as well as fatigue strength of gas welded joints. And also, the influence of the geometrical parameters of gas welded joints on stress distribution and fatigue strength must be evaluated. the ${\Delta}P-N_f$ curves were obtained by fatigue tests. Using these results, ${\Delta}P-N_f$ curves were rearranged in the ${\sigma}-N_f$ relation with the maximum stress at the edge of fillet welded joint.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.5
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• pp.698-704
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• 2012

Electric power used in electrical vehicles flows into the substation through the feedback circuit, track circuit. Due to these power conversion equipments in electrical railroads, return current contains harmonics, and it should not affect other communication lines. In this paper, based on the return currents, we measured harmonics and analyzed an influence in railway equipments due to the harmonics. For analysis, we utilize the measured values of return currents measured in track circuits, and predictive values of those compared to the earth methods between the existing electrified sections. Applying the regulations used for Gyeongbu HSL(High Speed Line), the results of measured harmonics have found to be acceptable.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.540-545
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• 2001

When a testing body is being inserted to the ground by Front Jacking Method, the influence of friction forces around the body plays important role in the characteristics of whole ground behavior. In the study, the Front Jacking Method that most frequently used in Korea who applied with experimental way. And the characteristics of ground behavior that caused by the friction that acts to the upper slab was analysed for the basic data that can be utilized for real scale experiment.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.7-10
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• 2006

In this study, Curve dependent wheel flange lubricator with spray type is investigated and estimated a point of view reducing wheel flange wear and noise, a small crack in the curve. Advantage of curve dependent wheel flange lubricator spray type is found on the basis of the result of field test in comparison with oil spray type lubricator and wheel without wheel flange lubricator on railroad in korea for noise and wheel abraison. the influence of curve dependent wheel flange lubricator spray type on the small crack of wheel is introduced by research papers