• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.951-952
• /
• 2006

Railway signaling systems are so vital to ensure the safe operation of railroad and the assurance and demonstration of the safety is so important. The safety management process shall consist of a number of phases and activities, which are linked to form the safety life-cycle. The basic processes of safety management and safety activity throughout the lifecycle are 'risk analysis' and 'hazard control'. The safety managements and activities for the two kinds of aspects are implemented throughout the whole steps of system lifecycle. The risk analyses and hazard controls like those are needed, these activities have to be carried out through the whole of system lifecycle.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.10a
• /
• pp.457-460
• /
• 2018

The mobile communication based train control is the train control system by utilizing wireless communication rather than conventional wired communication. Traditional train control operates train occupation, safety integrity and moving authority using fixed block wired railway signal system. Since introduction of mobile communication in railway area, railway operators can provide improved passager services. Futhermore, it can replace inefficient train onboard equipments and railway ground facilities for economic benefits. In this paper we introduce mobile communication based railway system currently in operation around the world. Moreover, we provide the minimum requirements of the radio communication performance. Proposed minimum requirements of the radio communication improve more secure and efficient mobile communication based train control system.

• Journal of the Korean Society for Railway
• /
• v.15 no.1
• /
• pp.29-36
• /
• 2012

This paper includes ATP(Automatic Train Protection) simulator development and ATP algorithm verification to allocate wayside and train-borne and verify ATP functions of communications based train control system. The train control system has some characteristics such as simple structure and high safety when wireless communication technology is applied to the train control system. Especially, vital functions can be performed with in wayside and train-borne ATP. However, different system can be realized because I/F contents vary in accordance with vital functional allocation of ATP. Drawing characteristics in accordance with wayside and train-borne functional allocation and drawing I/F details affected by such characteristics are needed accordingly. This paper includes ATP simulator development creating train location information by direct activation of an electric motor, verifies train safety distance control algorithm of ATP by functional allocation such as train movement authority and train speed limit to ATP, and draws any supplementation needed. Appropriate simulated environment for verify ATP algorithm and main factors that affect to the ATP function were confirmed.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.2076-2088
• /
• 2010

MMI (Man Machine Interface) is the system that monitors the operating condition of the ATP/ATC/ATS systems and receives defined information from ATP/ATC/ATS systems through the interface with On-board systems. Based on the data from the ATP/ATC/ATS system, MMI can display the information and status of the train to secure safe operation. It is possible for the display mode and quantities of MMI to be improved by the customer's demand, and it can be designed as the same structure of existing devices for the driver. The ERTMS is Regular Safety Standards of high-speed railroad. It is fundamental structure of European Rail Control System which train control, safety and operate facilities. In this paper, I study requirements of ERTMS form which design function each section of MMI and application at ATP/ATC/ATS combined Train Constrol System.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.4
• /
• pp.584-590
• /
• 2013

Depending on the operating characteristics, track circuit is installed for the purpose of control directly or indirectly of the signal device, point switch machine and other security device. These are mainly used for train detection, transmission of information, broken train detection and transmission of return current. Especially, the return current is related to signal system, power system and catenary line, and track circuit systems. It is one of the most important component shall be dealt for the safety of track side staff and for the protection of railway-related electrical system according to electrification. Therefore, an accurate analysis of the return current is needed to prevent the return current unbalance and the system induced disorder and failure due to an over current condition. Also, if the malfunction occurred by the return current harmonics, it can cause problems including train operation interruption. In this paper, we presented measurement and analysis method at return current and it's harmonics by train operation. By the test criteria, we evaluated for safety. Hereafter, it is expected to contribute to the field associated with it.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.472-475
• /
• 2009

Nowadays, Short headway is a requirement of Signaling System applied to subway and Light Rail Transit (LRT) being constructed in Korea. To satisfy this Systematic Requirement, the accuracy of train position information on the line is one of the main element to improve ATC system safety and performance. On-board ATC system performs feasibility of Train Position as comparing data from balise installed along the track with data from tachometer installed at both axles of train.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.117-124
• /
• 2011

The train control is a facility to ensure safe train operation, and its safety is the most important factor to determine whether introduced in railway authorities. Therefore, in order to improve practical usability in the business, safety analysis and evaluation of train control system and train control related core technologies are needed. In this paper, we develop wireless communication based train separation control simulator, the simulator traces trains in real-time, and produces train movement authorities with their position and speed information, and then calculates static and dynamic speed profiles. Trains in the simulator are controlled in real-time by these profiles. In the paper, simulator configuration, train control algorithm and simulation results under simulated environment are presented.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.5A
• /
• pp.389-396
• /
• 2005

In this paper, we design AVTMRWFSV(All Voting Triple Modular Redundancy With Fail-Safe Voter) System with a fail-safe output voter architecture and analyze RAMS(Reliability, Availability, Maintainability, Safety) as system failure rate. This system is compared with AVTMR system for RAMS(Reliability, Availability, Maintainability, Safety) with Markov modeling, and we can see that the system safety of AVTMRWFSV is more profitable than that of AVTMR. The dependability of AVTMRWFSV system is higher than that of AVTMR. Especially, safety is very profitable. So, this kind of system can be applied to embedded communication system and life critical systems - railway, airplane, ship, nuclear control system and so on.

• Journal of the Korean Society of Safety
• /
• v.36 no.2
• /
• pp.32-38
• /
• 2021

This paper suggests an approach to evaluate the reliability of an intelligent power module with information deficiency of prior distribution and the characteristics of censored data through Bayesian statistics. This approach used a prior distribution of Bayesian statistics using the lifetime information provided by the manufacturer and compared and evaluated diffuse prior (vague prior) distributions. To overcome the computational complexity of Bayesian posterior distribution, it was computed with Gibbs sampling in the Monte Carlo simulation method. As a result, the standard deviation of the prior distribution developed using simple information was smaller than that of the posterior distribution calculated with the diffuse prior. In addition, it showed excellent error characteristics on RMSE compared with the Kaplan-Meier method.

• Journal of the Korean Society for Railway
• /
• v.14 no.5
• /
• pp.416-424
• /
• 2011

The recent development of USN (Ubiquitous Sensor Network) technology has broadened its applications to many fields of industry. The USN technology enables the system to monitor and control the status of distributed sensor nodes based on the low-powered communications. Applying the USN in the train control domain, the operational efficiency can be enhanced, where the reliability and the safety of the system are the key challenges. This paper suggests the system design for evaluating and improving the reliability and safety of the gateway, which is a USN component that manages the radio network among the sensors and collects the information from them. For this purpose, the reliability and the level of safety integrity of a general gateway have been predicted quantitatively and the supplementary design has been proposed for the selected week points. The verification on the reliability and the safety of the improved gateway according to the related standards has been followed. With the results of the study, the applicability of USN gateway for train control systems has been reviewed.