• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.264-270
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• 2011

This paper reports a filtered velocity feedback (FVF) controller, which is an alternative to direct velocity feedback (DVFB) controller. The instability problems due to high frequency response under DVFB can be alleviated by the suggested FVF controller. The FVF controller is designed to filter out the unstable high frequency response. The FVF controller and the dynamics of clamped beams under forces and moments are first formulated The effects of the design parameters (cut-off frequency, gain, and damping ratio) on the stability and the performance are then investigated. The cut-off frequency should be selected not to affect the system stability. The magnitude of the open loop transfer function (OLTF) at the cut-off frequency should be small. As increasing the gain of the FVF controller, the magnitude of the OLTF is increased, so that the closed loop response can be reduced more. The enhancement of the OLTF at the cut-off frequency is reduced but the phase behavior around the cut-off frequency is distorted, as the damping ratio is increased The control performance is finally estimated for the clamped beam. More than 10dB reductions in velocity response can be achieved at the modal frequencies from the first to eighth modes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1066_1067
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• 2009

Wind power is one of most promising renewable energy. The output capacity of large wind turbine has been increased for off-shore application. Number of installation of small wind turbine also has been increased for the stand-alone and off-grid application of remote area and recently small wind turbine equipped with lamp on the pole is used for street lamp. Maximum wind energy must be extracted by wind turbine within rated wind speed. Power must be controlled to protect the system such as blade, generator, and power system above the rated wind speed. In this paper, small wind power system of 800W rating for battery charging is implemented and output power control by furling system is verified at wind tunnel test.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.813-815
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• 2016

본 논문에서는 뇌파데이터를 기반으로 한 디바이스 제어 시스템을 구현한다. Brain-Computer Interface(BCI) 기술은 언어나 신체의 동작을 거치지 않고 직접 시스템에 전달할 수 있다. 상태의 변화에 따른 뇌파를 실시간으로 감지하여 디바이스를 제어함으로써 움직임이 불편한 장애인이나 수험생, 멀티태스킹이 필요한 사람 등 다양한 서비스 대상자에게 편리한 생활을 할 수 있도록 도와준다. 또한, 홈 디바이스 제어 시스템 등 응용서비스를 개발할 수 있다. 이를 위해 논문에서 구현한 디바이스 제어 시스템은 뇌파 측정 헤드셋으로부터 수집된 데이터를 기반으로 사용자의 스마트폰과 연동하여 전원 및 오디오를 제어한다. 집중도에 의해 전원 ON/OFF 동작을 제어하고, 명상도와 눈 깜빡임에 의해 오디오를 제어하는 서비스 기능을 지원한다. 실험실 테스트를 통해 뇌파데이터를 이용한 디바이스 제어가 성공적으로 동작되는 것을 확인하였다.

• 전기의세계
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• 제16권3호
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• pp.16-20
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• 1967

To analyze the stability creterion and the dynamic performance of the nonlinear reactor control system which involve the on-off element and gear backlash, the concept of discribing function is developed for the system of two nonlinear elements are connected by linear element. Using the derived discribing function and frequency responce method, the stability creterion and the dynamic performance of the nonlinear reactor control system are analyzed, and the results of the analysis are conformed by analog computor.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.821-825
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• 1991

This paper presents an architecture and control logic of a Flexible Manufacturing Cell (FMC) which is one of the important elements under Computer Integrated Manufacturing (CIM) environment. To implement FMC, it is very important to develop a software which can control and monitor the overall system in an integrated environment. Our primary concern in this research is not to develop individual systems, but to integrate them in the hierarchical control level. Progress on the research of integrating CAD/CAM, Process Planning, Off-line Robot Programming and Simulation module into FMC control system is reported. FMC hardware system used here has an Automated Storage & Retrieval System (AS/RS), a conveyor system, a transfer robot, a CNC milling machine, a bar-code system, and an IBM PC/AT as Cell Control System (CCS). In order to demonstrate the operational result, the name plates, text-carved aluminium plates, are manufactured by this system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1840-1843
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• 1997

The task environment of a robot is changing rapidly and task itself becomes complicated due to current industrial trends of multi-product and small lot size production. A convenient user-interfaced off-line programming(OLP) system is being developed in order to overcome the difficulty in teaching a robot task. Using the OLP system, operators can easily teach robot tasks off-line and verify feasibility of the task through simulation of a robot prior to the on-line execution. However, some task errors are inevitable by kinematic differences between the robot model in OLP and the actual robot. Three calibration methods using image information are proposed to compensate the kinematic differences. These methods compose of a relative position vector method, three point compensation method, and base line compensation method. To compensate a kinematic differences the vision system with one monochrome camera is used in the calibration experiment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.283-287
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• 1996

The exhaust noise reduction of automobile with the active muffler is experimentally investigated. The control algorithm is the filtered-x LMS algorithm and the inverse algorithm with the adaptive line enhancer. Also, the control efficiency is increased with synthesized second harmonic engine frequency. In the experiment, the active muffler is applied to the end of exhaust system in automobile and the control with on-line secondary path modeling method(inverse algorithm) is compared the control of off-line secondary path modeling method. As secondary path transfer functions are changed, the experimental results show that the control performance with on-line method is more efficient than that with off-line method in the exhaust noise reduction of automobile.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.135-140
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• 2002

Studies on the optimization of machining process can be divided into two different approaches: off-line feedrate scheduling and adaptive control. Each approach possesses its respective strong and weak points compared to each other. That is, each system can be complementary to the other. In this regard, a combined system, which is a feedrate control system for cutting force optimization, was proposed in this paper to make the best of each approach. Experimental results show that the proposed system could overcome the weak points of two systems.

• Journal of Mechanical Science and Technology
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• 제19권2호
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• pp.529-539
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• 2005

The development of a fast, accurate, and inexpensive position-controlled pneumatic actuator that may be applied to various practical positioning applications with various external loads is described in this paper. A novel modified pulse-width modulation (MPWM) valve pulsing algorithm allows on/off solenoid valves to be used in place of costly servo valves. A comparison between the system response of the standard PWM technique and that of the modified PWM technique shows that the performance of the proposed technique was significantly increased. A state-feedback controller with position, velocity and acceleration feedback was successfully implemented as a continuous controller. A switching algorithm for control parameters using a learning vector quantization neural network (LVQNN) has newly proposed, which classifies the external load of the pneumatic actuator. The effectiveness of this proposed control algorithm with smooth switching control has been demonstrated through experiments with various external loads.

• 한국전자통신학회논문지
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• 제9권4호
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• pp.455-468
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• 2014

RF-CBTC 열차제어시스템 무선 정보 송 수신의 이상적인 값을 도출하기 위하여 운영기관인 신분당선을 모델로 하여 터널환경에서 측정 및 시험하고, 알고리즘을 제시하여 끊임없는(Seamless) Hand off를 구현하기 위한 방안을 마련하였다. 또한 주파수 간섭 및 재 전송률을 줄이기 위하여 이상적인 값(-57dB)을 제시하고, 무선통신을 이용한 열차제어 시스템의 안정적인 데이터 통신이 가능하도록 주파수 최적화를 증명하였다. 이러한 결과를 토대로 신분당선 2단계구간에 실무적용 할 계획이다.