• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.65-67
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• 2008

A new pulse width modulation method based on predictive current control strategy is proposed to modulate matrix converters. The predictive current controller utilizes a discrete-time model to predict the future values of output currents and generates proper duty-ratios ta minimize the output current errors. The proposed method uses continuous carrier and establishes a predictive current controller to predetermine duty ratio signal for directly generating gating signals an thus is named "predictive current control PWM(PCCPWM)". The modulation algorithm nd the required equations are derived by using average concept over one switching period. Thus it can be easily extended to other matrix converter topologies, especially with neutral connections, such as sing le-phase ad two-phase matrix converters. The feasibility and validity of the proposed strategy are verified by computer simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2555-2557
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• 2005

It is very difficult to control a motor and apply a mathematical algorism using regular micro controller. However we can embody a program using the graphic language faster and easier than using another language and conveniently compose the plate based on a PC through the DAQ board included AD and DA converter. In addition, The controllable system is made due to GUI program. I verified appropriateness PI control and determining a speed of BLDC motor which is nomally used through this program.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.481-483
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• 1989

This paper is concentrated on the recognition of Korean Digits. The speech signals of each of digits are fed into computer through the 18 bandpass filters, AD converter. Spectrum input data are analyzed and used. BASIC program language is used for recognition performance and the result of recognition is outputed to computer screen and printer. In this paper, the strength and weakness of filter-bank analysis method is described and the technique of real-time recognition is argued. In this experiment, Ratio of recognition for speaker dependent recognition was about 97% and recognition time was also satisfied. Therefore, A way of speaker independent recognition will be presented and using for special communication in the future.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.869-873
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• 1992

A fuzzy controller is designed for compensating the cross-coupling effect of induced roll due to the dynamic characteristics of three fin torpedo. Since the utilization of fuzzy-coprocessor has many interfacing problems with typical microprocessors of the guidance and control unit, the simplified fuzzy inference method based on nonfuzzy-processor is proposed to implement fuzzy controllers of three fin torpedo. This method provides a flexible rule-base design to guarantee the robust control. The good potential of the proposed design is shown through real-time simulations using both a mathematical model on AD-100 computer and an implemented controller on Intel 80C186/80C 187 microprocessors employing 12bit A/D converter.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.255-259
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• 1996

This paper describes a system for measurement and control of a gas flow. In order to measure the flux of gas and control a vavle according to flux, this system was developed. This system is implemented on the personal computer and its environment is developed tool called TMS. This system includes a main program and Tele-Metering Unit for transmitting correcting flow value based on temperature and pressure in flow computer and AD converter for transmitting instantaneous flow rate, temperature and pressure as interface part of personal computer. This system was made by Visual C++ program. Using this system, inspected data for the recognition of transmitting flow value are generated on the screen, file and printer. The activity, reliability of this system was verified on Daegu-Citygas that aids the system for the acquisition of inspected data by realtime application.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.403-410
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• 2015

This study documents the 3-phase BLDC(Brushless DC) motor to improve conventional exhaust fan motor. Energy efficiency, noise, and air pollution reduction for the high-performance vibration of the BLDC motor has been used in many fields. It is necessary to achieve the information of rotor position for driving 3-phase type brushless DC motor. It is also necessary that the PWM control algorithm design for a MOSFET driver to control the motor speed control for each of three phases. BLDC motors for exhaust fan, we studied the controller and software. The control circuit and motor control program through which Exhaust fan up close and person can be used safely and protect the environment.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.70-72
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• 2005

It is very difficult to control a motor and apply a mathematical algorithm using regular micro controller. However we can embody a program using the graphic language faster and easier than using another language and conveniently compose the plate based on a PC through the DAQ board included AD and DA converter. In addition, The controllable system is made due to GUI program. I verified appropriateness of variable of a speed and determining a speed of BLDC motor which is normally used through this program.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.7
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• pp.1777-1786
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• 1996

This paper describes theories and implementation techniques of a digital high-definition television(HDTV) modem based on 32-QAM for terrestrial broadcasting. We proposed a digital demodulation scheme and a symbol timing recovery structure based on the band edge component maximization(BECM) method. The adaptive equalizer has 256 complex taps to remove the multipath of delays ranging from -2.mu.s~+24.mu.s with a new T/2-spaced blind equalization algorithm. computer simulation results reveal that the proposed algorithm outperforms other conventional blind equalization algorithm a digital HDTV modem with 4.91MHz symobol rate is implemented by utilizing the proposed algorithms. All processings for modem operations such as demodulation, estimation of symbol timing phase error, adaptive equalization, and carrier recovery except IF signal processing and sampling phase control part of the AD converter are done in digital domain. Especially, the carrier recovery loop can track a carrier offset of upto .+-.350KHz.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.187.1-187.1
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• 2012

본 논문은 저궤도 위성의 각 유닛의 온도 정보를 획득하기 위해 사용되는 온도 센서인 써미스터의 data 처리를 위한 calibration 방법을 정리한 것이다. 써미스터는 온도에 따라 저항 값이 바뀌는 소자이며, 위성 프로세서는 정전류 소스를 공급하고 여기에 걸리는 전압을 AD converter를 이용해 데이터로 전송한다. 지상에서는 전송된 데이터를 calibration 공식에 대입하여 온도 정보를 얻어낸다. 특히 발사 준비 및 발사 후 발사체와 분리되기 전까지 계속 모니터링이 필요한 배터리 온도 정보의 경우 배터리 내부의 한 개 써미스터에 대해 발사장전기시험장비와 발사체의 MUX 시스템 그리고 위성 내부 프로세서에서 프로세싱이 동시에 이루어지기 때문에 각 시스템의 영향성까지 고려해야 한다. 본 논문에서는 저궤도 위성의 열진공 시험 및 발사 동안의 실제 데이터 처리 결과를 통해 정밀한 써미스터 데이터 처리 및 그 시스템 설계에서 고려해야 할 점들을 정리한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.33-40
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• 2014

Air compressor is an important facility with electric power in the industry. However, because of the noise and vibration of air compressor and is installed outside the building management difficulty. In this study, MCP (Micro Control Processor) to remote monitoring of the air compressor via the compressed air through improved quality and allows stable maintenance were designed. So, increase the productivity improvement of energy-saving effect can be obtained. Remote real-time information stored on your PC to manage air compressor equipment was higher reliability. Monitoring system is developed in this study was applied to embedded systems. It is easy to install air compressor, and low maintenance costs was to raise the economic impact.