• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.4
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• pp.739-746
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• 2016

The real-time railway safety monitoring and control system is for prevention of safety accidents, and this system adopts DDS (Data Distribution Service) standard based data transmission method to support integrated management of data from existing on-site safety detection devices. In this paper, we introduce the design of DDS-based data specification from on-site signal equipment on the conventional railway. For this, we (1) design UML data model of KRS SG 0062 standard which defines existing data specification, (2) define DDS Topics for DDS transmission and map KRS model to DDS Topic model, (3) suggest data transformation rules and (4) design network control QoS polices. In addition, we analysis actual on-site log data and validate our data specification design. DDS-based data transmission enables data compatibility among on-site devices and the real-time railway safety monitoring and control system, and allows efficient network management for a large amount of data transfer.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1784-1786
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• 2004

PD(Partial Discharge) signal emitted from PD sources has their intrinsic features in the region of time and frequency. STFT(Short Time Fourier Transform) shows time-frequency distribution at the same time. 2-Dimensional matrices(33${\times}$77) from STFT for PD pulse signals are a good feature vectors and can be decreased in dimension by wavelet 2D data compression technique. Decreased feature vectors(13${\times}$24) were used as inputs of Back-propagation ANN(Artificial Neural Network) for discrimination of Multi-PD sources(air discharge sources(3), surface discharge(1)). They are a good feature vectors for discriminating Multi-PD sources.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1475-1480
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• 2013

In this paper, the basic design study of a water-cooling jacket, which have reported no cases for applying to railway traction motors so far, were conducted for applying to Interior Permanent Magnet Synchronous Motor (IPMSM) for railway vehicles. The basic thermal characteristics analysis of the 110kW-class IPMSM was performed by using 3-dimentional thermal equivalent network method. The necessary design requirements of the water-cooling jacket were derived by analyzing the results of the basic thermal properties. Next, the thermal characteristics analysis technique was established by using the equivalent model of the solenoid-typed pipe to be installed on the inside of the water-cooling jacket for 110kW-class IPMSM. Finally, a design model of 6kW-class water-cooling jacket was derived through the analysis of various design parameters.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1254-1256
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• 2001

This paper composes the Electric Railway System with the common grounding based on the 5-port network model. We compare the magnification ratio of harmonic currents according to locations of RC bank(i.e s/s. sp, and pp). It takes a lot of costs to equip the RC-bank at all location. And it is NOT effective that RC-bank is equipped at S/S. Finally, this paper proposes SP as the optimal site of RC-bank aspect reducing harmonic.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.1097-1100
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• 2005

This study explored the ridership pattern between Seoul and Busan after the introduction of KTX in 2004. Since the KTX opening, average daily passengers on the Kyungbu lines have increased. These figures clearly indicate that the transportation network is becoming railroad-centric. However, the operation. of the KTX will leave many existing Saemaul and Mugunghwa train sets idle, which will be put into operation for areas, not covered by the KTX. Statistics show that the railroad ridership is clarified the distinction between train service levels. So, our paper studied the change of market share by service levels between Seoul-Busan line which is a long distance route.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.1153-1158
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• 2005

The e-mailing system has brought in an innovative information sharing of data communications and gained ground as an essential tool in doing business which ranges from delivering inside information. exchanging messages between groups and with customers to electronic advertisements. Making the most of the network communication technology, entrepreneurs have established a solid mailing system in their groupware and portal system where they carry out interactive communications through the aerial transmission. This paper analyzes the research results in the field of mailing system of the railroad portal installed by the Korea Railroad Research Institute and illustrates what has been derived in the course the software development at the same time.

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.118-123
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• 2013

This paper presents performance comparison between concentrated winding and distributed winding of IPMSM (Interior Permanent Magnet Synchronous Motors) which is recently used for light-weight railway applications. Motors are designed on various schemes and analyzed by using FEM (Finite Element Method) instead of EMCNM (Equivalent Magnetic Circuit Network Method) in order to take into account saturation and non-linear magnetic property. The overall performance such as torque, torque ripple, losses, demagnetization, efficiency, power density and so on are investigated in detail at the rated and maximum operating speed. The results of the analysis found that both concentrated and distributed winding IPMSMs are promising candidates for high power railway traction motor.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2612-2614
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• 2003

최근 들어 무선통신환경 하에서 빠른 이동 속도를 갖는 이동체를 위한 빠른 핸드오프 기술들에 대한 연구가 활발히 진행되고 있다. 열차도 이러한 빠른 이동체의 대표적인 예가 될 것이다. 지금까지 열차제어방식은 선로변 설비인 궤도회로를 이용한 지상과 차상간의 정보전송을 통하여 이루어져 왔다. 이 경우 선로변의 궤도회로에 대한 유지보수 등의 비용이 과다하고, 또한 열차의 위치검지가 궤도회로의 구간별로 이루어지는 등의 단점이 있어 최근 들어 무선통신을 이용한 열차제어 방법이 활발히 진행되고 있다. 이에 따라 미래에는 고속의 이동성을 갖는 열차도 무선통신에 의한 서비스가 될 것으로 예상된다. 이러한 무선통신을 이용한 열차의 서비스를 위해서는 열차의 빠른 이동속도로 인해 무선 기지국 셀 영역들간의 빠른 핸드오프 기술을 필요로 한다. 본 연구에서는 열차제어에 적용 가능한 여러 핸드오프방식들을 분석하였다. 그리고 높은 이동성이 요구되는 고속의 이동체인 열차를 위한 핸드오프 방안을 제안한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.221-222
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• 2005

In this paper, application of NN (Neural Network) as a method of pattern discrimination of PD(partial discharge) which occurs at the stator coil of traction motor was studied. For PD data acquisition, three defective models are manufactured such as internal discharge model, slot discharge model and surface discharge model. PD data for recognition were acquired from PD detector and DAQ board which is able to analysis the PD signal and perform the pattern discrimination. Statistical distributions and parameters are calculated to discriminate PD sources. And also these statistical distribution parameters are applied to classify PD sources by BP and has good recognition rate on the discharge sources.

• Journal of the Korean Society for Railway
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• v.17 no.1
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• pp.59-69
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• 2014

Recently, the building of an intermodal transportation system has become the most important policy in the establishment of a national-wide sustainable transport system. In the case of rail and public transport, an intermodal connecting improvement policy is essential due to the lack of trip completeness. In particular, high-speed rail has brought dramatic changes to the transportation system in Korea and the idea of high-speed rail stations as major transportation nodes to be linked to various travel modes needs to be analyzed in terms of an intermodal network. Thus, this study proposes a new connectivity analysis method to objectively and quantitatively evaluate intermodal connecting performance for high-speed rail in terms of an intermodal network around high-speed rail stations. Seoul, Busan, Ulsan, and Sin-gyeongju stations were designated for a range of spatial analyses; detailed connecting performance indexes of travel modes connecting high-speed rail stations, and the influence sphere of these stations are analyzed, except for internal transfer facilities. Finally, this study proposes a connectivity analysis method that applies the structural equation model and develops a connectivity index.