• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1134-1141
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• 2011

Costs have long since become a major issue in railway system analysis, attention is not limited to the acquisition costs alone, but encompasses all costs involved in the use and disposal of the systems. Concepts such as Life Cycle Cost(LCC), Costs Of Ownership(COO), or Total Ownership Cost(TOC) are more and more frequent in any document dealing with system analysis. Most of railway projects have applied this LCC Model to evaluate effectiveness of system acquisition cost. But these action of LCC model does not applied all the rest of system life cycle period due to the differences of its responsibility. This is why a study has been undertaken by the operation party to harmonize the most important aspects of the LCC model. This study focused on these and other objectives for introduction of method and needs for an action plan for maintenance actions involved relevant cost allocation.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.444-451
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• 2003

In this study, a new three-dimensional finite element analysis model of high-speed railway bridges considering train-bridge interaction, in which various improved finite elements are used for modeling structural members, is proposed. The box-type bridge deck of a railway bridge is modeled by the NFS(Nonconforming Flat Shell) elements with 6 degrees of freedom. Track structures are idealized using the beam finite elements with the offset of beam nodes and those on Winkler foundation with two parameters. And, the vehicle model devised for a high-speed train is employed, which has an articulated bogie system. By Lagrange's equations of motion, the equations of motion of a bridge-train system can be formulated. Finally, by deriving the equations of the forces acting on a bridge considering bridge-train interaction the complete system matrices of total bridge-train system can be constructed. As numerical examples of this study, 2-span PC box-girder bridge is analyzed and results are compared with experimental results.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.116-122
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• 2000

This paper presents a simulation method with constant power model for the train load. In power system simulation loads could be modeled as a constant power, constant current, constant Impedance or a function of voltage and frequency. At this time, however, representing a train load as the function is difficult because of the lack of data. Therefore as a first step, simulation method with a constant power model fer a train is studied, and the test result is compared with the simulation result using the constant Impedance model.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.8
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• pp.1210-1215
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• 2012

Traction motors for driving and power conversion devices using semiconductor switch are equipped with a transportation systems such as an electrical railway system. Power conversion devices have the possibility of malfunction by external electromagnetic waves. As a result, these could affect the safe operation of the railway. Moreover, the electromagnetic waves above safe limits will be harmful to the passengers inside the railway vehicles or anyone working around the rail-track. For this reason, the importance and need about the reliability check and complement of electromagnetic waves generated from the IPT(Inductive Power Transfer) system have been suggested for the safe application of the IPT system to the railway system. In this study, prediction for the electromagnetic wave properties was conducted through FEM(Finite Element Method) analysis of 5kW-class IPT system design model. Next, the 5kW IPT system prototype was made and then the small-scaled railway vehicle was made to mount the IPT system and the energy management system. Finally, the electromagnetic waves generated from the real small-scaled IPT system were measured and analyzed, and then the reliability check of predictions by FEM analysis were carried out.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.12 s.117
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• pp.1231-1237
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• 2006

The vibration of a running railway vehicle can be classified on lateral, longitudinal and vertical motions. The important factor on the stability and ride quality of a railway vehicle is the lateral motion. The contact between wheel and rail with conicity influences strongly on the lateral motion. In this study, an experiment for the vibration of a running railway vehicle was performed using a of the scale model of a railway vehicle. Also, the effects on the car-body, bogie and wheelset were examined for the weight and the stiffness of the second suspension system. The experimental results showed that the lateral vibration increases as the wheel conicity and stiffness of the second suspension system increase. And the lateral vibration of the bogie increases as the mass ratio between car-body and bogie increases. Also, the lateral vibration of the wheel becomes high at low speed, while the wheel of 1/20 conicity makes severe vibration at high speed running.

• Journal of the Korean Society of Safety
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• v.24 no.3
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• pp.79-87
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• 2009

The objective of this study is to develop accident scenario models for the risk assessment of railway casualty accidents. To develop these scenario models, hazardous events and hazardous factors were identified by gathering various accident reports and information. Then, the accident scenario models were built up. Each accident scenario model consists of an occurrence scenario model and a progress scenario model. The occurrence scenario refers to the occurrence process of the event before the hazardous event. The progress scenario means the progress process of the event after the hazardous event. To manage a large amount of accident/incident data and scenarios, a railway accident analysis information system was developed using railway accident scenario models. To test the feasibility of the developed scenario models, more than 800 domestic railway casualty accidents that occurred in 2004 and 2005 were investigated and quantitative and qualitative analyses were performed using the developed information system.

• Journal of the Korean Society for Railway
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• v.10 no.4
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• pp.438-443
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• 2007

This paper proposes an integrated SE process for the development of railway systems with safety assessment included. Although the safety assessment process must be performed with SE process properly with good coordination, the interfaces between the two processes have not been clear. Thus, in many of safety critical system developments in Korea, it is difficult to assess safety in proper development phase. The process model proposed in this paper is based on both the concept of system life cycle and the repetitive use of SE process. In each of development phases, appropriate safety assessment methods are described. Also the evaluation of the integrated system incorporating safety factors is described. The resultant process model is expressed by the Enhanced Functional Flow Block Diagram (EFFBD) using a CASE tool. The model also allows timeline analysis for identifying activity flow and data flow, resulting in the effective management of process. In conclusion, the integrated process enable both the SE process and safety assessment process to cooperate with each other from early development phase throughout the whole system life cycle.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.393-395
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• 1998

This paper presents a modeling of railway facilities based on object-oriented software development technique for train operation simulation program. Railway network is decomposed by Line Structure Model and Signal System Model which can be composed to make the train routes and train performance calculation. A brief explanation of class design about these model is provided.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.354-357
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• 2004

According to the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by the digital communication channel. At the same time, the importance of the communication link is more pronounced than in the past. In this paper, new network-based protocol for Korean railway signaling has designed between CTC and SCADA system, and the overview of designed protocol is briefly represented. Using the informal method for specifying the communication protocol, a little ambiguity may be contained in the protocol. To clear the ambiguity contained in the designed protocol, we use LTS model to design the protocol for this interface link between CTC and SCADA, the LTS is an intermediate model for encoding the operational behavior of processes. And then, we verify automatically and formally the safety and the liveness properties through the model checking method. Especially, the modal ${\mu}$-calculus, which is a highly expressive method of temporal logic that has been applied to the model checking method. It will be expected to increase the safety, reliability and efficiency of maintenance of the signaling systems by using the designed protocol for railway signaling in Korea.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1118-1125
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• 2010

This paper presents the methods to acquire the Safety Certificate from Independent Safety Assessment based on the IEC standard62279 which is commonly applied to railway system for Automatic Train Control(ATC) system in accordance with Urban Maglev project. This also shows approach methods and relative activities for project life-cycle to accomplish and ensure the system requirements of ATC system, RAMS and S/W quality activities. Furthermore, the key tasks conducted with ISA are noted in detail. These kind of activities for software quality of ATC system to obtain Safety Certificate could be a CASE model to improve the quality of domestic railway system and products, and also contribute to the growth of railway business and toward the achievement of overseas' railway signaling markets.