• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.4
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• pp.72-83
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• 2002

In this paper, a novel low-power VLSI system architecture was proposed. By exploiting software control of supply voltages, it simplifies hardware implementation, reduces power consumption efficiently, and avoids complicated interface circuits. The proposed architecture models clock frequency-supply voltage relationship by software modelling, enables individual control of supply voltages for all chips in the system, and restricts clock frequency to discrete levels of $f_{CLK}$, $f_{CLK}$2, $f_{CLK}$3... where $f_{CLK}$ is the master clock frequency A prototype system was implemented by modifying off-the-shelf microprocessor evaluation board and adding simple discrete devices such as level shifters and voltage switches. It was measured that the power consumption was reduced from 0.58W to 0.12W in the Prototype system. system.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.25-27
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• 2002

종래 가스절연개폐장치용 제어 패널은 아날로그 제어방식으로 제어 패널의 시퀀스 제어회로를 계전기, 스위치, 카운터, 타이머, 파이로트 램프, 경보 표시장치, 케이블 등을 이용하여 구현한다. 그래서 제어 패널 내부에 각종 계전품과 케이블이 많이 필요하게 되어서 복잡한 것이 단점이다. 또한, 시퀀스 제어회로의 수정이 필요하면 계전품, 배선을 수정해야 하므로 제어 패널의 유연성이 낮다. 이것을 디지털 제어 패널로 대체하면 아날로그 제어방식으로는 구현하기가 어렵거나 불가능한 기능들을 쉽게 구현할 수 있으며, 시퀀스 제어회로의 수정이 필요하면 종래에는 계전품, 결선을 수정해야 했으나 소프트웨어의 수정만으로 가능하여 제어 패널의 유연성이 향상되며 제어기의 내부가 PCB 보드로 되어 있어서 제어 패널의 유지보수성이 향상되며, 종래에는 계전품 케이블을 이용하여 구현한 기능들이 소프트웨어로 가능하게 되므로 제어 패널의 배선이 많이 축소되어 조립 작업성이 향상되고 원가절감이 가능하다. 원격 통신기능이 가능하여 SCADA/REMOTE와 통신으로 연결되어 변전소 종합자동화에 적합하다.

• Journal of IKEEE
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• v.22 no.4
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• pp.1152-1157
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• 2018

In this paper, we try to solve the difficulties of the location of the structure for the movement of the wire - based pesticide spraying equipment designed for field farming. To do this, we apply earth resistivity measurement method and analysis technique which can indirectly grasp the earth structure. Electrodes are installed on the field in a selected farming area, and multi-switches built in the control board are driven to automatically acquire ground resistivity data. Then, the optimal point suitable for the actual structure installation is selected through the site analysis using the 2D image restoration algorithm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.5
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• pp.10-24
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• 2007

In the dissertation, a power conversion system for fuel cell is composed of a PWM inverter with LC filter in order to convert fuel cell voltage to a single phase 220[V]. In addition, new insulated DC-DC converters are proposed in order that fuel cell voltage is boosted to 380[V]. In this paper, it requires smaller components than existing converters, which makes easy control. The proposed DC-DC converter controls output power by the adjustment of phase-shift width using switch $S_5\;and\;S_6$ in the secondary switch which provides 93-97[%] efficiency in the wide range of output voltage. Fuel cell simulator is implemented to show similar output characteristics to actual fuel cell. Appropriate dead time td enables soft switching to the range where the peak value of excitation current in a high frequency transformer is in accordance with current in the primary circuit. Moreover, appropriate setting to serial inductance La reduces communication loss arisen at light-load generator and serge voltage arisen at a secondary switch and serial diode. Finally, TMS320C31 board and EPLD using PWM switching technique to act a single phase full-bridge inverter which is planed to make alternating current suitable for household

• Journal of IKEEE
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• v.25 no.3
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• pp.485-492
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• 2021

In this paper, we propose the development of a defect inspection system for polygonal containers. Embedded board consists of main part, communication part, input/output part, etc. The main unit is a main arithmetic unit, and the operating system that drives the embedded board is ported to control input/output for external communication, sensors and control. The input/output unit converts the electrical signals of the sensors installed in the field into digital and transmits them to the main module and plays the role of controlling the external stepper motor. The communication unit performs a role of setting an image capturing camera trigger and driving setting of the control device. The input/output unit converts the electrical signals of the control switches and sensors into digital and transmits them to the main module. In the input circuit for receiving the pulse input related to the operation mode, etc., a photocoupler is designed for each input port in order to minimize the interference of external noise. In order to objectively evaluate the accuracy of the development of the proposed polygonal container defect inspection system, comparison with other machine vision inspection systems is required, but it is impossible because there is currently no machine vision inspection system for polygonal containers. Therefore, by measuring the operation timing with an oscilloscope, it was confirmed that waveforms such as Test Time, One Angle Pulse Value, One Pulse Time, Camera Trigger Pulse, and BLU brightness control were accurately output.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.43-54
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• 2017

This paper analyzes the performance of two three-leg inverters and a five-leg inverter and proposes the optimal operation conditions in applying the five-leg inverter for the train propulsion system. The five-leg inverter offers a saving of two switches compared with the standard two three-leg inverters and it is possible to control two three-phase motors independently by using a control board. All of these features lead to a potential reduction in capital cost and miniaturization of system. In this paper, first, the analysis of the existing motor control method and PWM method for two-traction motor drive of urban railway is implemented. Next, the operation principle and performance of five-leg inverter is introduced. Through the analysis, when it applies the same motor control method and the same PWM method for three-leg inverter and five-leg inverter, the characteristic of motor's speed and torque is compared.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.11
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• pp.981-987
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• 2014

DC/DC switching power converters are commonly used to generate a regulated DC output voltage with high efficiency. The DC/DC converter is composed of a MOSFET (metal-oxide semiconductor field effect transistor), a PWM-IC (pulse width modulation-integrated circuit) controller, inductor, capacitor, etc. It is shown that the variation of threshold voltage and the breakdown voltage in the electrical characteristics of MOSFET occurs by radiation effects in TID (Total Ionizing Dose) testing at the low energy ${\gamma}$ rays using $^{60}Co$, and 5 heavy ions make the gate of MOSFET broken in SEGR (Single Event Gate Rupture) testing. TID testing on MOSFET is accomplished up to the total dose of 40 krad, and the cross section($cm^2$) versus LET(MeV/mg/$cm^2$) in the MOSFET operation is studied at SEGR testing after implementation of the controller board.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.4
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• pp.347-350
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• 2017

In this paper, we implemented a real-time 2.4 GHz direction finding system using a time-modulated array(TMA) and an Universal Software Radio Peripheral(USRP). Our system consists of two commercial monopole antennas, self-designed switch board, and an USRP, and it is controlled using LabVIEW program in real-time. From measured results, it is verified that our system can exactly detect the incident angle within 4 degree in the range of 30 degree. Our direction finding system has advantages of a simple hardware architecture than conventional one with multiple receivers, and a simple algorithm only by using a main lobe and a first side-lobe of switching frequency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.11C
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• pp.1164-1170
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• 2002

In the ACE2000 MPLS system, MPLS Interface Module(MIM) is composed of an ATM Interface Module and a HFMA performing a packet forwarding. In the MIM, the HFMA RSAR receive cells from the Physical layer and reassemble the cells. And the IP Lookup controller perform a packet forwarding after packet classification. Forwarded packet is segmented into cells in the HFMA TSAR and transfer to the ALMA for the transmission to an ATM cell switch. When the MIM make use of an ATM Interface Module, it directly connect the ALMA with a PHY layer using the UTOPIA Level2 interface. Then, an ALMA performs Master Mode. Also, the HFMA TSAR performs the Master Mode in the MIM. Therefore, the UTOPIA-L2 Controller of the Slave Mode require for interfacing between an ALMA and a HFHA TSAR. In this paper, we implement the architecture and cell control mechanism for the UTOPIA-L2 Controller supporting Multi-ports.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.239-245
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• 2016

In this study, a 12 V PWM boost converter was designed with the optimal values of the external components of the power stage was well as the compensation stage for smart electronic applications powered by a battery device. The 12 V boost PWM converter consisted of several passive elements, such as a resistor, inductor and capacitor with a diode, power MOS switch and control IC chip for the control PWM signal. The devices of the power stage and compensation stage were designed to maintain stable operation under a range of load conditions as well as achieving the highest power efficiency. The results of this study were first verified by a simulation in SPICE from calculations of the values of major external elements comprising the converter. The design was also implemented on the prototype PCBboard using commercial IC LM3481 from Texas Instruments, which has a nominal output voltage of 12 V. The output voltage, ripple voltage, and load regulation with the line regulation were measured using a digital oscilloscope, DMM tester, and DC power supply. By configuring the converter under the same conditions as in the circuit simulation, the experimental results matched the simulation results.