• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.5
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• pp.877-884
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• 2017

A method of common earth, which is proposed by French Railway(SNCF) and is applied to high speed railway, minimizes the effect of the traction return current from tracks so that trackside electric devices can be protected and operation and maintenance staffs are kept out from injury in an electric railway environment. According to it, all the new domestic electric railway lines are replaced from existing individual earth method to the common earth method. In this paper, we analyze the correlation between common earth method and traction return current to prove whether the common earth has surely contributed to minimize the effect of the traction return current. The analysis was done based on the measurement of the traction return current at the domestic high speed railway line.

• Journal of Microbiology
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• v.44 no.2
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• pp.145-154
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• 2006

Heterotrimeric G proteins (G proteins) are conserved in all eukaryotes and are crucial components sensing and relaying external cues into the cells to elicit appropriate physiological and biochemical responses. Basic units of the heterotrimeric G protein signaling system include a G protein-coupled receptor (GPCR), a G protein composed of ${\alpha},\;{\beta},\;and\;{\gamma}$ subunits, and variety of effectors. Sequential sensitization and activation of these G protein elements translates external signals into gene expression changes, resulting in appropriate cellular behaviors. Regulators of G protein signaling (RGSs) constitute a crucial element of appropriate control of the intensity and duration of G protein signaling. For the past decade, G protein signaling and its regulation have been intensively studied in a number of model and/or pathogenic fungi and outcomes of the studies provided better understanding on the upstream regulation of vegetative growth, mating, development, virulence/pathogenicity establishment, and biosynthesis of secondary metabolites in fungi. This review focuses on the characteristics of the basic upstream G protein components and RGS proteins, and their roles controlling various aspects of biological processes in the model filamentous ascomycete fungus Aspergillus nidulans. In particular, their functions in controlling hyphal proliferation, asexual spore formation, sexual fruiting, and the mycotoxin sterigmatocystin production are discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1303-1310
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• 2016

The track circuit carries out a train detection using a electrical closed loop, and incidentally it detects the rail rupture using the track circuit current flowing rail. However, in the case of the axle counter or the Radio based train control system, it requires a new way for detecting the rail rupture because of not using the track circuit. To solve this problem, it periodically checks non-steady state of rail by the track inspection car. but real-time detection of the rail rupture is impossible. Therefore, this paper analyzed feasibility to realize a real-time detection of rail rupture by using the return current.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.5
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• pp.375-384
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• 2021

The development of the European Railway Traffic Management System (ERTMS) began in 1989 as part of the European Union policy to establish a unified and interoperable railway route in Europe. It is a trend that ERTMS/ETCS(European Train Control System) is becoming an international standard in the railway signaling system. As the solution to this situation, the domestic railway signaling field is also at a time when it is more necessary to develop the technology of the train control system considering interoperability. The European Railway Agency (ERA) has proposed B3R2 (Baseline 3 Release 2) for new ETCS-equipped trains after 2020.12.31. In Korea, Baseline 2.2.0 to 2.3.0d on Gyeongbu Line, Honam Line, Jeolla Line, and Gyeongchun Line was installed and now is under operating. As the Baseline upgrade continues, technical considerations and economic considerations are an occurring trend. In this paper, we analyzed the main functions and compatibility of the currently distributed European standard ERTMS/ETCS Baseline 3 and presented a plan to apply the domestic KTCS(Korean Train Control System) Baseline in the near future.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.427-436
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• 2018

HADAX is a serial communication converter of train control computer. It is connected with various signal equipments such as wayside signal equipments, station signal equipments, train control computers, and transmits control information and signal condition information for train control. And transmits information to several electronic interlocking devices through a splitter interface. Since HADAX interfaces with many signaling devices through serial communication, frequent communication connection faults necessitate improvement of performance such as dual system configuration, integration of external splitter, and multi-channelization of communication card. The improved HADAX device should have compatibility with the dimensions of existing enclosure and enclosure, and verify the performance of dual system and splitter integration. Therefore, we verified the performance of HADAX through the route control test, dual system test, and multi-channel communication test with splitter integrated connection by connecting with the existing signal equipment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.2
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• pp.242-253
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• 1994

For the implementation of a Service Node, which is proposed in the companion paper to provide multiparty conference type sevices in the ISDN, we define some technical aspects such as connection control, service control procedure and control messages in this paper. Additional connection control procedures for the multiparty connections are annexed to the CCITT Rec. Q.931 and Q.764 for the ISDN subscriber and common channel interoffice signaling. A new set of service control procedures is also established according to the necessary service control functions. The messages for these procedures are formatted using user-to-user signaling parts of Q.931 and Q.763 messages not to affect on the existing signaling system. Some technical requirements of subscriber terminal for the multiparty services are also deduced.

• Journal of the Korean Society for Railway
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• v.18 no.5
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• pp.426-438
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• 2015

Train speed controlling systems are now changing from wayside systems to onboard signaling systems. Locomotive engineers refer to wayside markers to decide on a braking point when the train speed appears to be lower than the current speed. However, in the onboard signaling systems that have been installed recently, the braking point is not determined by the wayside signal but by an onboard value. In this paper, we studied braking points and methods for deciding on such points by engineers using the onboard systems. An optimized braking point is proposed via simulation of decelerating velocity to control the velocity in the signaling system through a predefined point; Gaussian distributions are used to simulate the actual situation. We estimated and demonstrated how to obtain braking parameters in order to satisfy the interval of permitted error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.256-263
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• 2009

KORAIL carries out an improvement project of railway signaling system for the conventional line from the existing method which permits a train to move within limited speed the ground signal of ATS(Automatic Train Stop) system. The proposed system makes possible that a train can be driven using a speed profile created by onboard signaling system(ATP) with the movement authority from ground balise. A driving test over 100,000km is being executed by developing a tilting train for the speed elevation on the conventional line. And, the introduction of the tilting train by ATP system to the Jung-ang line is expected. However, a speed elevation on a curved line section has a restriction. Therefore, research on safety braking model and train separation control technology for the localization of ATP system is required preferentially. In this paper, we presented a safety braking model of ATP system and a train separation control method that use ground balise as variable information provider, and executed a performance simulation.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.56-58
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• 2005

This paper for the Train control system which has been used in the railway system for the purpose of headway control is regarded as safety-critical system, which is based on embedded controller. Therefore, for the maintainability, the maintenance time shall be predicted correctly in order to improve availability of railway system and the predictive values shall be proved through the test. In conclusion, for the maintainability of train control system, the solution for exact prediction based on related international standard and the system for justification of derived predictive values shall be proposed.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1016-1020
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• 2005

The real-time monitoring and controlling between the interior and the field signaling security devices is a necessity for the train safety in terms of the train operating plan. The type wiring lower the safety level of signaling security device, because too much wiring makes the maintenance more difficult and it might be have a problem of an induction field and contact. It also need high cost. The single network communication(Fieldbus) does not need that much wiring, and the maintenance will be easier. It also guarantee the high level of stability.