• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.711-717
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• 2017

The railway is a public transportation system that provides large-scale passenger transportation and service, whose reliability and safety is the top priority. The wiring of railway vehicles is classified into train control lines (train lines) and communication lines. The train lines are used for input / output signals related to vehicle driving and safety functions, and the communication lines are used for the input / output signals for passenger services such as broadcasting. In order to measure the reliability of railway vehicles, a train line is applied to the input / output interface of the control signals between the electric control devices in the vehicle, and there are many electromechanical devices such as relays and contactors for the control logic. In fact, since the vehicle control circuit is composed of several thousand contacts, it is difficult to check for errors such as contact failure, and it is impossible to check the real-time status, so a lot of manpower and time is required for regular maintenance. Therefore, we analyze the current state of the train line design of the electric equipment used for driving and services in domestic railway cars and propose three wiring reduction methods to improve it. Based on the analysis of domestic electric vehicles, it was confirmed that the wiring reduction effect is 35% or more.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.3
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• pp.54-61
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• 2002

A remote image transmission apparatus combines robot technology and image transmission there is safe problem or place that a person can not go. Recently, control apparatus that use wire and RF between web server and robot for remote control are developed. But there is problem that must install internet line and communication distance. Transmission distance problem call solve when using the equipment of RF, but price of RF router is problem that is very high cost. In this paper, we developed remote control system using the CDMA cellular phone communication network that can control image transmission and image transmission apparatus to solve these problem. Developed system could solve defects of methods that use existent RF and internet. And could transmit the most suitable image and voice under limited condition include current communication network.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.4
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• pp.167-174
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• 2003

This paper proposes a network processor especially optimized for content switching. With 2Gbps port capability, it integrates packet processor cluster, content-based classification engine and traffic manager on a single chip. A switch fabric architecture is also designed for scale-up of the network processor's capability over hundreds gigabit bandwidth. Applied in real network systems, the network processor shows wire-speed network address translator (NAT) and content-based switching performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2518-2524
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• 2009

This paper presents the backplane effects due to a rectangular aperture size for two-wire transmission line with equal line length crossing the changeable rectangular aperture in an infinite ground backplane. It is used to determine the characteristics of the backplane insertion loss of the transmission line from the load section in accordance with the backplane aperture size. The results show that the insertion gain and insertion loss are obtained for the specific frequency range when the transmission line is closed to the backplane aperture size. The insertion loss is decreased that the aperture horizontal length and vertical length is more than a=50 mm and b=20 mm. The measurements of insertion loss are performed to verify the theoretical analysis.

• Journal of Internet Computing and Services
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• v.3 no.1
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• pp.1-10
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• 2002

A remote image transmission apparatus combines robot technology and image transmission there is safe problem or place that a person can not go. Recently, control apparatus that use wire and RF between web server and robot for remote control are developed. But, there is problem that must install Internet line and communication distance. Transmission distance problem can solve when using the equipment of RF, but price of RF router is problem that is very high cost. In this paper, we developed remote control system using the cellular phone communication network that can control image transmission and image transmission apparatus to solve these problem. Developed system could solve defects of methods that use existent RF and internet. And could transmit the most suitable image and voice under limited condition include current communication network.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.1-7
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• 2013

This paper analyzes the flashover rate by lightning in Korea distribution system. Because of random characteristics of lightning, the Monte Carlo method is applied to estimate the lightning performance. The magnitude of lightning stroke is based on the curve measured in field. The classification of direct and indirect lightning depends on the striking distance. The striking distance and flashover rate are calculated by using the method based on Central Research Institute of Electric Power Industry(CRIEPI). The distribution system and lightning is modeled by using EMTP and MATLAB, and the accuracy of modeling is discussed. The simulations for the various spacing between two adjacent surge arresters and the various grounding resistance of GW according to the existence of GW are performed and the simulation results are analyzed.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.70-80
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• 2006

The large portion of communication service areas move from a legacy wire-line voice service to mobile data service. For the purpose of satisfaction on market need, many communication systems should be installed and upgraded based on a mobile wide-band transmission facility. Recently, large part of communication service is based on internet protocol by packet switch techniques and required new technologies such as multimedia processing, QoS achievement, and mobility managememobile communication network such as IS-95A/B and CDMA2000-1X. In this paper, I analyzed the network architecture and service provision methods. in CDMA2000-1X nt. In korea, a CDMA communication technique is standardized for digital mobile communication systems. By using the analysed results, I will extract an efficient method for network evolution and a core technique for next generation mobile communication network.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.3
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• pp.183-188
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• 2014

Power conversion systems used in large gas turbine power plant can be divided into two main part. Because of the initial start-up characteristic of the gas turbine combustor, the gas turbine must be accelerated by starting device(LCI : Load Commutated Inverter) up to 10%~20% of rated speed to ignite it. In addition, the ECS(Excitation Control system) is used to control the rotor field current and reactive power in grid-connected synchronous generator. These two large power conversion systems are located in the same space(container) because of coordination control. Recently, many manufactures develop high speed controller based on function block available in the LCI and ECS with the newest power semiconductor. We also developed high speed controller based on function block to be using these two system and it meets the international standard IEC61131 as using real-time OS(VxWorks) and ISaGRAF. In order to install easily these systems at power plant, main controller, special module and IO module are used with high speed communication line other than electric wire line. Before initial product is installed on the site, prototype is produced and tests are conducted for it. The performance results of Integrated controller and application program(SFC, ECS) were described in this paper. The test results will be considered as the important resources for the application in future.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.2
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• pp.251-256
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• 2017

This study developed an image processing system for detecting damages on underground spiral PVC pipes. The detection method is simple-identifying damaged areas by measuring circularity along the pipeline. This uses the assumption that damage parts will not make a circular shape. Conventional devices check the circular shape of the pipe along the pipeline by measuring the angles between 6 spring-connected legs on the device. The conventional device, however, requires the insertion of 3 different wires (electrical, communication, and camera lines) along with a guide wire for pulling the device. The developed system presented here has simplified this system, requiring only a camera line while maintaining reasonable accuracy in damage detection.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.653-658
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• 2003

This study is represented a method to give connect to optical cable from accident site and reviewed the method to transmission a moving image to control centre by real time, following the study of image transmission method in copper cable section where is a main line of railroad communication. Concept of network is studied to use cable and equipment effectively, and it's also reviewed technology of digital image transmission system and image evaluation methods, in spite of the pixel of camera and monitor resolution determine quality of image when moving image transferring by point to point. In addition, this study is reviewed checks and considerations of image transmission equipment (codec) with various transmission methods in room test, and then examined and analyzed wire/wireless combined transmission methods at wayside.