• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.1
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• pp.121-131
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• 1999

Automatic Rudder Trim System(ARTS) is a device to reduce the pilot's work load for rudder trimming greatly required in varying abruptly aircraft's engine power. This paper represents a technical analysis and a design of control law of the ARTS. The control law of the ARTS is designed based on the analysis of aircraft's characteristics, system's requirements, and limitations. The control law is comprised of open loop control using the rudder trim map for a specific aircraft and closed loop control to compensate the error of the open loop control system. flight test results show that the ARTS can reduce pilot's work load for rudder trimming dramatically and can compensate the aircraft's transient yaw motion.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.11
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• pp.36-42
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• 2007

In this paper, we have studied temperature compensation architecture for a bust mode optical transmitter to convert the electric burst mode date signal to a optical one through the laser diode. In order to get stable high speed data transmission, we used digital sampling technique with a microprocessor for the temperature compensation of the laser diode, not the previous real time analog technique. Though the digital automatic power control circuit should be complemented the previous analog one with accuracy and effectiveness. So the digital technique will be more effective in further future in development for the over Gb/s transmitting speed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.619-625
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• 2000

A many control techniques have been proposed in order to improve the control performance of the discrete-time domain control system. In the position control system, the output of a controller is generally used as the input of a plant but the undesired noise is included in the output of a controller. Therefore there is a need to used a precompensator for rejecting the undesired noise. In this paper, The expanded I-PD control system with a precompensator is constructed. The precompensator and I-PD controller are designed by a neural network and these coefficients are changed automatically to be a desired response of system when the response characteristic of system is changed under a condition.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.84-90
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• 2004

Many control techniques have been proposed in order to improve the control performance in the control system. In the feedback control system the output of controller is generally used as the input of a plant But the undesired noise is included in the output of a controller. Therefore, there is a need to use a precompensator for rejecting the undesired noise and improving the response characteristic of a system. In this paper, the design method of a precompensator is proposed for the model following control in the I-PD control system. The proposed precompensator is implemented with a neural network. The games of a precompensator are adjusted automatically to obtain a desired response of a system when the response characteristic of a system is changed under a condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.304-307
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• 1995

In this paper, an optical sensing system has been developed to detect the dust in vacuum cleaner. The system works well through self-tuning mechanism, even though there are systemic variance and characteristic change which is caused by the pollution on the surface of the optical elements. Using the developed sensing system, a novel suction power control system has been proposed, which is able to be used for a long time.

• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.51-60
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• 2024

Aiming at the problem of low contrast and difficult to recognize video images in low-light environment, we propose an adaptive contrast compensation enhancement algorithm based on human visual perception. First of all, the video image characteristic factors in low-light environment are extracted: AL (average luminance), ABWF (average bandwidth factor), and the mathematical model of human visual CRC(contrast resolution compensation) is established according to the difference of the original image's grayscale/chromaticity level, and the proportion of the three primary colors of the true color is compensated by the integral, respectively. Then, when the degree of compensation is lower than the bright vision precisely distinguishable difference, the compensation threshold is set to linearly compensate the bright vision to the full bandwidth. Finally, the automatic optimization model of the compensation ratio coefficient is established by combining the subjective image quality evaluation and the image characteristic factor. The experimental test results show that the video image adaptive enhancement algorithm has good enhancement effect, good real-time performance, can effectively mine the dark vision information, and can be widely used in different scenes.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.11a
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• pp.323-332
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• 2000

정밀을 요하는 자동차 부품의 측정 시스템은 온도에 따른 보상이 필수적이다. 부품의 측정값의 신뢰도를 유지하기 위해서 단순히 제품의 합격 영역을 상온에서 51.786～51.819mm로 했을 때, 온도가 상온에서 떨어져 있는 경우 그 부품의 측정영역을 신뢰하기가 어려워진다. 본 논문에서는 이 문제를 해결하기 위해서 2개의 카메라를 사용하여 한쪽은 표준 제품을 두고, 다른 쪽은 실제 제품을 두므로서 온도에 따라 달라지는 표준 제품의 측정값의 Offset를 실제 제품에 반영하므로 측정값을 보상하려고 하였다. 자동차의 부품은 여러 가지가 있으나, 이 중에서 현재 공장에서 측정에 어려움을 겪고 있는 에어콘 스윗치인 마그네트 코일 하우징을 대상으로 하였다. 특히 측정 대상이 크고, 카메라의 화소수가 40만 이하일 경우, 측정의 중요한 포인트는 화소수이기 때문에 이를 정확히 알아 내는데, FCM(Fuzzy C-means) 알고리듬이 좋은 결과를 주지만 속성 공간에서 유사성만을 고려하고, 공간영역에서 유사성을 고려되지 않기 때문에 FCM은 \"equal evidence\"와 \"ignorance\"를 구분하지 못한다. 이를 개선하기 위해서 FCM를 수정하여 먼저 FCM로 처리하고 하고 이를 바탕으로 PCM(Possibilistic C-means)를 사용하였다. 결과를 모니터에 보여주고, RSC-232 포트를 통하여 신호를 마이크로프로세서에 전달하여 제품의 양호(good), 불량(bad)을 판별하는 신호를 발생하게 하였다.을 판별하는 신호를 발생하게 하였다.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.49-52
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• 2004

본 논문에서는 켑스트럼 기반의 후두질환 음성의 자동감별시, 훈련 및 테스트 마이크 불일치로 인한 채널 왜곡을 보상하기 위한 방법에 대해 연구를 하였다. 특징벡터 영역에서의 채널보상 방법으로 기존의 Cepstral Mean Subtraction (CMS) 방법과 Pole Filtering CMS (FPCMS) 방법을 이용하였다 실험결과 FPCMS를 적용한 경우 기존의 CMS에 비해 우수한 성능을 보이고, $40\%$의 인식 오류 감소를 얻었다.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.512-513
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• 2010

최근 일정전압의 신뢰성 있는 전원공급 장치의 개발에 대한 필요성이 날로 증가하고 있다. 기존의 AVR(Automatic Voltage Regulator)은 디지털식이므로 고장시 수리하는데 많은 어려움이 있지만 기계식AVR은 고장시 즉각 대처 할 수 있기 때문에 신뢰성 있는 전원공급 장치로 볼 수 있다. 본 논문에서는 PM(Permanent Magnet)동기발전기에 부하가 걸렸을 때 전원이 리액턴스로 인한 전압강하가 생기므로 기계식AVR을 이용하여 보상하고자한다. SVR(Slidac Voltage Regulator)형 자동전압장치와 절연변압기를 이용하여 기계식AVR을 설정하는 방법을 제시하고 PM동기발전기와 연결하여 전압강하를 보상하는 시뮬레이션을 통하여 검증하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.2
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• pp.166-176
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• 2000

In this paper, the LEO system signal degradation is mainly due to fading and doppler shift, so that the analysis of the signal degradation and compensation techniques are very important. This paper propose a Kalman filter based two step Automatic Frequency Control(AFC) to combat large and time variant frequency offset in low earth orbit satellite communication systems. The proposed Kalman AFC method estimates a frequency offset in two steps, I. e., coarse and fine estimations, extending the frequency acquisition range to even for than the symbol rate. Furthermore, it can track well a time variation of frequency offset. It is shown that the proposed compensator is able to compensate for doppler shift more than several KHz.