• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.6
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• pp.538-545
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• 2001

In this paper a gearless drive system using a permanent-maget synchronous motor for high speed elevators is addressed. The application of permanent magnet synchronous motor to an elevator traction machine enables several improvements including higher efficiency better ride comfort smaller size and lighter weight and so on A PWM boost converter has been also adopted so that DC-link voltage regulation bi-directional power flow and controllable power factor with reduced input current harmonics are possible. To increase the reliability and performance of overall control system the unified control board which can include the car and group controller as well as PWN converter/inverter controller has been designed based on a DSP TMS320VV33. In addition the dynamic load simulator system has been developed so that the drive system of high speed elevator can be tested and evaluated without and limitation on ride distance. Some experimental results are given to verify the effectiveness of the developed system.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.951-956
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• 2011

CAN communication developed for communication between electric control devices in vehicle, was recently applied to automatic breaking devices, and can also be applied to field bus for production automation. Recently, field bus is introduced in engine control etc., for large ship. In this paper, cabin access control system is implemented, based on CAN communication. The cabin access control system based on CAN communication consists of access control server, embedded system based on ARM9, and micro-controller built-in CAN controller. The access control server can be able to manage overall access control system by accessing with manager. And embedded system adopted ARM9 processor transmits access information of RFID reader controller connected with CAN networks to server, also performs access control. The embedded system carry CAN frames to server, so it is used as gateway.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.467-470
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• 2009

CAN communication developed for communication between electric control devices in vehicle, was recently applied to automatic braking devices, and can also be applied to field bus for production automation. Recently, field bus is introduced in engine control, etc. for large ship. In this paper, cabin access control system can be implemented, based on CAN communication. The cabin access control system based on CAN communication consists of access control server, embedded system based on ARM9, and micro-controller built-in CAN controller. The access control server can be able to manage overall access control system by accessing with manager. And embedded system adopted ARM9 processor transmits access information of RFID reader controller connected with CAN networks to server, also performs access control. The embedded system can carry CAN frames to server, so it can be used as gateway.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.4
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• pp.379-387
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• 2011

Research and development of LP EGR system for the performance improvement and emission reduction on diesel engine is proceeding at a good pace. LP EGR system seems to be helpful method to further reduce$NO_x$ emissions while maintaining PM emissions at a low level because the boost pressure is unchanged while varying EGR rate. This study is experimentally conducted on a 2.0L common rail DI engine at the medium load condition (2000 rpm, BMEP 1.0 MPa, boost pressure 181.3 kPa) that difficult to use large amount of EGR gas because of deteriorations of performance and fuel consumption. And we investigated the characteristics of performance and fuel consumption while varying EGR systems. The overall results using LP EGR system equipped with ETC identified benefits on reduction of PM and improvement of fuel consumption and thermal efficiency while keep the $NO_x$ level compared to HP EGR and LP EGR with back pressure valve.

• Journal of the Korean Society for Railway
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• v.15 no.1
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• pp.37-41
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• 2012

Kyung-Bu High Speed Railway is operated in train control system(tcs) of fixed block operated in a way of dividing track circuits into several blocks in accordance with operation circumstances such as rolling stocks, grade, curves and facilities. The TCS of fixed block system refers to a continuous train control system, which transfers operational information such as entry and exit speed, distance-to-go, and deceleration etc. into on-board train control equipment on the basis of block occupancy of a preceding train. It guarantees a safe operation of trains by giving an emergency braking order, in case that a train exceeds an entry and exit speed of a corresponding block. In this paper, we analyze the speed control code deducing in accordance with maximum operation speed and characteristics of rolling stocks by analyzing principles of generation of speed control code allocated in blocks for safe operation, then train operational efficiency was analyzed by means of analysis of operation headway in accordance with the deduced speed control code. This study will be used to design in case of getting an increase in speed for existing high speed line or new high speed line TCS.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.5
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• pp.507-511
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• 2019

The use of regenerative energy in AC drive systems has been an issue since the system became an industry standard in the 1990s. According to the quantity of the regenerative energy, the braking resistor in the case of low capacity was common. However the use of such low amount of energy is actively discussed, and the method of mounting the regenerative converter is becoming popular. In this paper, an isolated regenerative converter for reducing the circulating current which is mentioned as the biggest disadvantage of the conventional power regenerative converter system is proposed. In order to save energy, employing a power regenerative converter system for utilizing regenerative energy in an AC drive system is common. However due to the structure of the system, a circulating current is generated, which inevitably causes a decrease in efficiency. In this paper, an isolated regenerative power converter system is proposed to solve the circulating current and computer simulation to verify the possibility. The simulation results show that 20% of the circulating current of the conventional system does not appear in the proposed system, and the validity of the proposed system is confirmed.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.172-181
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• 1999

The brakes employed on commercial vehicles must be able to withstand three types of demanding services which are use-emergency stops from high speed, many repeated stops as in a delivery or bus route, and speed control in mountain descents. Two type of friction brakes are in use ; drum breaks and disc brakes. Drum brakes are of the internally expanding type in which two shoes fitted externally with friction material are forced outward against the inside of a rotating drum on the wheel unit. In this case, the Braking power is produced by the friction force between a drum and a lining, and is converted into heat. In this research an unsteady state heat transfer analysis for drum brake system of heavy truck has been performed by ABAQUS/standard code in the case of single-braking and the repeated braking condition. The temperature histories obtained by the finite Element analysis have been compared with the result calculated by the simplified formulation and the result obtained by the experiment of real vehicle conditions.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.176-179
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• 2010

본 논문에서는 고속철도 폐색분할 설계를 위한 요구사항을 도출하였다. 경부고속철도 열차제어시스템은 고정폐색방식으로 KTX가 차량의 물리적 특성, 선로환경 등을 고려하여 분할된 폐색구간을 진입할 때, 선행열차의 점유폐색을 기준으로 궤도회로로부터 해당폐색의 열차 진입/진출속도, 운행가능거리, 감속도 등의 운행정보를 전송받는다. 그리고 차상열차제어시스템은 지상에서 수신한 운행정보를 통해 열차제어곡선을 생성하고 열차가 해당폐색의 기준속도를 초과했을 경우, 비상제동명령을 내려 열차의 안전한 운행을 보장한다. 폐색분할은 열차의 안전한 운행을 위해 고정폐색방식에서 수행되는 기본설계로, 폐색분할 설계 결과는 궤도회로를 비롯한 지상열차제어장치의 수량을 산정하는 기준이 된다. 따라서 본 논문에서는 최고운행속도 300km/h로 운행하는 경부고속철도 폐색분할 설계를 기준으로 폐색분할을 위한 입력요구사항에 대해 분석하였다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.82-91
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• 2003

Vehicle dynamics control (VDC) has been a breakthrough and become a new terminology for the safety of a driver and improvement of vehicle handling. This paper examines the usefulness of a brake steer system (BSS), which uses differential brake forces for steering intervention in the context of VDC, In order to help the car to turn, a yaw moment can be achieved by altering the left/right and front/rear brake distribution. The steering function achieved through BSS can then be used to control lateral position in an unintended road departure system. An 8-DOF non-linear vehicle model including STI tire model will be validated using the equations of motion of the vehicle, and the non-linear vehicle dynamics. Since fuzzy logic can consider the nonlinear effect of vehicle modeling, fuzzy controller is designed to explore BSS feasibility, by modifying the brake distribution through the control of the yaw rate of the vehicle. The control strategies developed will be tested by simulation of a variety of situation; the possibility of VDC using BSS is verified in this paper.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.852-858
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• 2009

This paper is a study on the reliability management of onboard signaling equipment for the Koran Tilting Train (TTX) to run the existing railway to express railway. For safe running of tilting train which operates at Automatic Train Protection (ATP) and Automatic Train Stop (ATS), a reliability management plan for TTX onboard is proposed for preventing train safety from driver oversight and malfunction by establishing braking curves based on movement authority and speed limit, according to preceding train location and rail conditions. Also, reliability of TTX onboard equipment on the basis of proposed plan was estimated, and actual case studies based on the international requirements IEC 62278 (EN 50126) were provided to verify its reliability.