• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1437-1443
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• 2004

In this paper, AC electric vehicle propulsion system(Converter/Inverter) using high power semiconductor, IPM(Intelligent Power module) is proposed. 2-Parallel operation of two PWM converter is adopted for increasing capacity of system and the VVVF inverter control is used a mixed control algorithm, where the vector control strategy at low speed region and slip-frequency control strategy at high speed region. The proposed propulsion system is verified by experimental results with a 1,350kW converter and 1.100kVA inverter with four 210kW traction motors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.595-601
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• 2015

These days, research related to Intelligent Transportation System (ITS) technology is being widely considered. ITS is inevitable for future transportation systems to reduce accidents, congestion, and offer a smooth flow of traffic. The use of Visible Light Communication (VLC) in ITS systems has been considered widely because of its EMC/EMI free and LED infrastructure reusable properties. Among the VLC schemes, this study analyzed the performance of the Color Shift Keying (CSK) scheme under a Vehicle-to-Infrastructure (V2I) downlink scenario to verify the capability of CSK as a communication tool for ITS. By modeling daylight noise using the modified Blackbody radiation model, this study examined the performance of V2I VLC under daytime conditions. The relationship between BER, the communication distance, and the amount of ambient-light noises under the pre-described V2I scenario were determined by simulations.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.390-392
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• 2001

This paper presents an intersection of technologies of ITS (intelligent transport systems) and CBTC(communication based train control) in urban transit system. ITS is based on Information and communication technologies. And also these techniques are fundamental for railway system. ITS has some technologies useful in railways such as traveler information service, public transportation information service, and advanced vehicle control Systems. Therefore, both systems need to technological cooperation. In this paper, we proposed useful an cooperation method for both systems.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1756-1760
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• 2008

In this study, it was suggested how to monitor the air quality with use of intelligent wireless sensor network in the subway station. When Zigbee-based ubiquitous sensor network was used, smaller budget was required in configuring the system compared to existing air-quality monitoring method and this system may easily be configured due to easy installation of communication cables. The study will be continued to supplement the network systems currently installed in subway stations and the completion of development of this system is expected to make a large contribution in improvement of indoor air quality.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.339-342
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• 2008

In this paper, the lessons and learns are introduced from the result of the trial project which is the first CBTC(Communication Based Train Control System) at Korail Bundang Line. This project has started end of 2002 and finished recently by Samsung SDS. The main purpose of this project was that new technology was seek for next generation of railway signal control system adapted in Korea. In 2002, there was no any revenue service system using Radio Frequency CBTC in the world at that time. Just a few trial project was on going in USA and EU. In well developed cities, the metro system have been built and old enough therefore they have to be considering re-signalling their existing system with advanced system for increasing availabilities of line usage and safety. This Bundang Line Trial Project was the first Korean CBTC project for above reasons. Most sub systems have been developed using local technology such as Electronics Controlled Interlocking System and Track Circuit Systems etc. Specially, in this project the RF-Communication devices are developed by local technology using DSSS(Direct Sequency Spread Spectrum) instead of FHSS(Frequency Hopping Spread Spectrum). This project has lasted for more than five years originally planned for three years because it was only accessible only night time in the main line from Ori to Suseo about 20km long. Each night only 2 and half hours are available to use the main line. Now the trial project has been done successfully with meet the customer's requirement, therefore the upgrade the mainline of Bundang line and another extension area up to Wangsipli to make revenue service using this new technology. This paper shows this result of the trial project and the strategy of upgrade and extension project as well.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1499-1504
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• 2007

This dissertation explains the construction of the expert system which can manage diagnosis and administration of trouble using circuit diagram through connection between BOM and ability term and makes up for problem which have designed RIMS with name of parts. Also this dissertation explains that existing BOM has no regard organic relation of parts and functional and systematic appearance of the flow of electricity or air. Construction of expert system and "Be enlivened BOM" with flowing electricity and air can solve problems about overlapping parts carrying out other functions with the same name of parts following to simple and physical BOM　management and having mistaken trouble of the end caused by basis for trouble of the end.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.12
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• pp.1220-1225
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• 2010

This paper proposes a novel active noise control (ANC) approach that uses an IIR filter and neural network techniques to effectively reduce interior noise. We construct a multiple-channel IIR filter module which is a linearly augmented framework with a generic IIR model to generate a primary control signal. A three-layer perceptron neural network is employed for establishing a secondary-path model to represent air channels among noise fields. Since the IIR module and neural network are connected in series, the output of an IIR filter is transferred forward to the neural model to generate a final ANC signal. A gradient descent optimization based learning algorithm is analytically derived for the optimal selection of the ANC parameter vectors. Moreover, re-estimation of partial parameter vectors in the ANC system is proposed for online learning. Lastly, we present the results of a numerical study to test our ANC methodology with realistic interior noise measurement obtained from Korean railway trains.

• Journal of Internet Computing and Services
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• v.21 no.4
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• pp.109-116
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• 2020

With the advent of high-speed railways, railways are one of the most frequently used means of transportation at home and abroad. In addition, in terms of environment, carbon dioxide emissions are lower and energy efficiency is higher than other transportation. As the interest in railways increases, the issue related to railway safety is one of the important concerns. Among them, visual abnormalities occur when various obstacles such as animals and people suddenly appear in front of the railroad. To prevent these accidents, detecting rail tracks is one of the areas that must basically be detected. Images can be collected through cameras installed on railways, and the method of detecting railway rails has a traditional method and a method using deep learning algorithm. The traditional method is difficult to detect accurately due to the various noise around the rail, and using the deep learning algorithm, it can detect accurately, and it combines the two algorithms to detect the exact rail. The proposed algorithm determines the accuracy of railway rail detection based on the data collected.

• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.364-370
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• 2008

In this paper, we proposed new sensor network architecture with autonomous robots based on beacon mode and implemented real time monitoring system in real test-bed environment. The proposed scheme offers beacon based real-time scheduling for reliable association process with parent nodes and dynamically assigns network address by using NAA (Next Address Assignment) mechanism. For the large scale multi-sensor processing, our real-time monitoring system accomplished the intelligent database processing, which can generate not only the alert messages to the civilians but also process various sensing data such as fire, air, temperature and etc. Moreover, we also developed mobile robot which can support network mobility. Though the performance evaluation by using real test-bed system, we illustrate that our proposed system demonstrates promising performance for emergence monitoring systems.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1032-1038
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• 2008

KTX train system is composed of TORNAD* network for transmitting information of train's internal equipments and OBCS which proceed information within train. OBCS of one trainset consisted of 28 equipments takes intelligent and dynamic composition according to equipment handling, train command and control flow. Each OBCS which is installed within trainset handle and supervise mutually action information about equipments, transmit it to driver to transmit information about train operation and preventive management. This mutual supervision and information transmission use KTX TORNAD* network system. TORNAD* network system is the one which is uniquely developped by GEC ALSTHOM, the KTX trainset manafacturing provider and this field is excluded from technical know-how transfer item. Through the research on analysis method of KTX TORNAD* system data structure which is operating on Seoul-Pusan Line, I hope that this thesis can contribute to train network system's standardization after applying it to improvement of train network system maintenance, enhancing quality of train service and applying it to future Korean rolling stock network system development.