• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.2
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• pp.98-111
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• 1990

In this paper a queneing model for the D channel access protocal recommeded by CCITT is developed, and delays of the signalling and packet messages are analyzed using the model, Behaviors of packet and signalling messages in the D-channel access system are also investigated. The analytical results have been verified by simulation.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.163-166
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• 1997

In order to shorten head-way time on existing railway lines without any change of signal block length between stations, it is a realistic optional way to change the control method of train signal, i.e. to modernize the cab signal using transponder. A new signalling system of operation pattern control technique is suggested as new model to increase the railway traffic efficiency. Through the computer simulation of this model, the train head-way time by the fixed signalling system and the new pattern control system is analyzed.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.202-209
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• 1998

This paper presents a modelling of railway facilities and signalling system based on object-oriented software development technique to simulate multi-train movements on the complex railway network. Block and interlocking functions of signalling system is modelled using Node-Link model of railway network and signal control logic, which can be used to set the train routes and control the train movement. A brief explanation of class design about these model is provided.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.59-62
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• 1998

Satellite communication systems will play an important role in establishing high-speed information communication network ddue to the characteristics of flexibility of bandwidth, mobile communication, wide coverage, multipoint and broadcasting. Also satellite systems have the capability to supply terrestrial B-ISDN with flexible links for accessing networks as well as trunking networks. Therefore, satellites must provide compatibility to earth-based B-ISDN signalling interface, services and network capability. This paper proposed interworking model between terrestrial B-ISDN and satellite B-ISDN signalling protocol and illustrated basic call-process procedure of satellite B-ISDN signalling protocol supporting point-to-point and point-to-multipoint connection.

• International Journal of Railway
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• v.2 no.3
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• pp.107-112
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• 2009

Research projects of SNCF aim at reducing the costs of infrastructure possessions and improving the operational equipment availability and safety. This permanent search for a better regularity led the SNCF to analyse the maintenance approach of signalling equipment in detail. Until now, it was commonly acknowledged that signalling equipment, which consists of many electronic devices, is not subject to aging. In this study, a Weibull lifetime model, able to describe an aging phenomenon, is used and it can be shown that the deterioration is statistically significant. The validity of the model is tested. We also analyse the influence of environmental covariates. We simulate different scenarios in order to investigate the impact of several maintenance strategies as well as on future maintenance costs, on the amount of components to replace based on the mean age of the network. It can be shown that in most cases a systematic replacement strategy offers the best solution.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.5
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• pp.44-54
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• 1996

Various types of B-ISDN bearer connection can take place according to access types of endpoint equipments in call and number of connectio between endpoints. In this paper, performance of application signalling protocol on three basic facilities of B-ISDN CS-2 signalling system, such as connection of point-to-point, point-to-multipoint and multiconnection call, is evaluated and compared. For performacne evaluation, experimental model of B-ISDN application signalling protocol is implemented and respective message processing time of each process is measured. By applying message processing time to local exchange system, cal processing capacity of application signalling protocol on three basic connection types is evaluated by simulation method. In this paper, local exchange system is considered to have two ATM NNI links and four ATM UNI links.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.462-467
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• 2003

According to the computerization of railway signalling system, necessity of communication protocol for interface between these equipments is increasing. Therefore the research on communication protocol structure that is required according to computerization trend of these signalling goes. In our research the existed protocol currently used was analyzed, and the simulation modeling for performance analysis is deduced. Based on this simulation model the performance analysis and comparison is carried out, and also validation test is executed about new suggested protocol.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1318-1320
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• 2003

According to the computerization of railway signalling system, necessity of communication protocol for interface between these equipments is increasing. Therefore the research on communication protocol structure that is required according to computerization trend of these signalling goes. In our research the existed protocol currently used was analyzed, and the simulation modeling for performance analysis is deduced. Based on this simulation model the performance analysis and comparison is carried out, and also validation test is executed about new designed protocol.

• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.535-541
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• 2009

The reliability of control system composed of electronic parts has been studied by DoD since 1960, and has been undertaken mainly by Europe for railways. Especially in Korea, a study on reliability of signalling equipment has been taken since 2000, requiring reliability test for effective maintenance of old type signalling equipment which no longer has information on its past reliability. This study evaluates the reliability test in units of parts for old type signalling equipment; for instance, failure rate in units of parts, or failure data during operation; which was utilized without its consistent reliability monitoring and analysis data for over 20 years. Also, reliability change at this point in time has been estimated by using residual life span function, and a model which can evaluate the possibility of extended operation through stress acceleration test has been developed. This model will be utilized to establish future maintenance policy for train operating company's operation on old type signalling equipment.

• Journal of the Korean Society for Railway
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• v.6 no.2
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• pp.9-18
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• 2003

This paper discuss advanced safety in the railway signaling system. The specified methods and HAZOP about Hazard identification and analysis of railway signalling system were studied, and loss analysis and ALARP model in order to calculate safety as a standard capacity were proposed. It was also resulted from Hazard identification, analysis and evaluation by applying advanced safety to the railway signalling system.