• Title/Summary/Keyword: Noise Removing

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A method of dynamic error reduction for a sensor with first order lag using a digital convolution integrator

  • Kubota, Nobuhisa;Mine, Katsutoshi;Doi, Masanori
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.530-533
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    • 1993
  • This paper describes a new method of dynamic error compensation, using a digital convolution integrator and two digital low pass filters. In this method, the process of compensation consists of three steps. First, sampling and digitizing of input signal, second, removing the noise in sampled data by the low pass filter and third, making a convolution integral using the output data of low pass filters. This method showed a good experimental result of reducing dynamic error even if there was a slight noise in the input signal. As a result, the detecting time constant of resistance thermo-bulb was improved to about 1/10th.

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A novel three-phase power system for a simple photovoltaic generator (태양광발전을 위한 새로운 3상한 시스템에 관한 연구)

  • Park, Sung-Joon;Kim, Jung-Hun;Kim, Jin-Young;Kim, Jeoung-Hyun;Kim, Hee-Je
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.181-184
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    • 2005
  • Operating conditions of photovoltaic power generator is very sensitive to the PV modules. The PV module's control is an importance issue in the removing DC ripple noise. In this paper, the phase-shifted-carrier technique, which is a new three-step dc-dc power multi-converter schemes, is applied to solar generator system to improve the output current waveform. The novel type of three-step dc-dc converter presented has many features such as the good output waveform, high efficiency, low switching losses, low acoustic noise. The circuit configuration is constructed by the conventional full-bridge type converter circuit using the isolated DC power supply for which the solar cell is very suitable. In the end, a circuit design for understanding three-step dc-dc converter and new solar power system were presented

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Virtual Acoustics Field Simulation System for the Soundscape Reproduction in Public (공공장소의 음풍경 재현을 위한 가상음장현장재현시스템 개발)

  • Song, Hyuk;Kook, Chan;Jang, Gil-Soo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.4
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    • pp.319-326
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    • 2004
  • The soundscape is a novel attempt to offer comfortable sound environments at the urban public spaces by adding pleasant sounds and removing unagreeable ones. Most important factors to be considered therein are to determine what kind of sounds to offer and how to adjust them to the changing circumstances. But, installing, maintaining and adjusting the soundscape system directly in the field will ensue numerous problems as well as high costs. Thus, it is essential to devise a test method to analyse and verify the outcome before the actual installation in the field takes place. This study aims at devising the instrument system that enables to control. with a great ease, numerous variables. reproduce most agreeable sound sources, and can verify the effects on the virtual simulatory settings, which is named as Virtual Acoustic Field Simulation System (VAFSS).

Model Updating in Small Structural Dynamics Model by Elimination of Mass Loading Effect of Accelerometer (가속도계 영향을 제거한 소형 구조물의 동특성 모델 개선)

  • Lee, Jung Youn
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.25 no.1
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    • pp.40-47
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    • 2015
  • Dynamic response of any small structure is always affected by the mass of the attached accelerometer. This paper predicts the natural frequencies and frequency response functions by removing the mass loading effect from the accelerometer. This mass loading is studied on a simple cantilever beams by varying the location of accelerometer. By using sensitivity analysis with iteration method, accelerometer mass and location are obtained. The predicted natural frequencies of the small cantilever beam without the accelerometer's mass show good agreement with the structural re-analysis.

Estimation of Flow-induced Vibration characteristics on Plugged Steam Generator (관막음된 증기발생기 전열관의 유체유발진동 특성 평가)

  • Cho, Bong-Ho;Ryu, Ki-Wahn;Park, Chi-Yong;Park, Su-Ki
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.921-926
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    • 2002
  • In this study, we investigate the plugging effect on the CE type steam generator tube. The natural frequency and mode shape will be changed due to decrease of the effective mass distribution along the tube. We compared the variation of stability ratio for plugged tube with that for unplugged one. The natural frequency increased because of removing the cooling water inside the steam generator tube, but the stability ratio decreased inversely because of changing the vibrational model shape. We also investigated the turbulent excitation effect.

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A Study on Detection of Significant point in ECG using Neural Network (신경회로망을 이용한 ECG 특성점 검출에 관한 연구)

  • Sohn, Sang-Yoon;Jeong, Kee-Sam;Chung, Sung-Jin;Lee, Myung-Ho
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.11
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    • pp.109-112
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    • 1995
  • This paper is a study on the detection of the significant point in ECG signal. ECG signal consists of two components; one is high frequency component to be detected and the other is low frequency component to be removed. AR model is appropriate for modelling and removing the low frequency component. AR model coefficients are updated by artificial neural network algorithm. We can remove the background noise(low frequency) by passing through the AR filter. The remaining signals which include high frequency noise are sent to the matched filter to pass only the signal which we want to extract. The template used in matched filter is updated adaptively.

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Implementation of Multi-adaptive Filter for EOG Removal and Biofeedback Output Controller

  • Ahn, Bo-Sep;Kim, Pil-Un;Cho, Jin-Ho;Kim, Myoung-Nam
    • Journal of Korea Multimedia Society
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    • v.7 no.12
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    • pp.1650-1656
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    • 2004
  • In this paper, a multi-adaptive filter is proposed for removing EOG and the 60 Hz power supply noise from EEG measured in the frontal lobe and the feedback output control method is implemented for biofeedback. The multi-adaptive filter has been implemented on the TMS320C6711 DSP system and the feedback output control algorithm has been realized by calculating the ratio of alpha wave on the TMS320C31 DSP system with real time performance. Through the experiment using the implemented multi-adaptive filter and feedback output controller, we demonstrate that the proposed adaptive filter effectively removes EOG and the 60 Hz power supply noise from the measured EEG in the frontal lobe and the feedback algorithm controls the level of stimulation by the ratio of the alpha wave.

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Biological signal processing using syntactic pattern recognition (SYNTACTIC 패턴인식에 의한 생체신호처리)

  • Kim, Yong-Man;Kim, Jung-Hun;Jeong, Hee-Kyo;Lee, Myoung-Ho
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1284-1287
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    • 1987
  • A method of quantitative electrocardiogram analysis, based on concepts drawn from syntactic pattern recognition theories, is described. The algorithm can be used for removing the Interference noises and base line drift as a filter function, and for reducing the number of points representing the digitized ECG waveform. The Parsing is performed with simple finite state automata inferred by experiments and suitable to be updated during experiment execution. Two parameters are utilized for defining the noise and these make the algorithm flexible. The examples for testing the algorithm is real ECG waveforms with noise. Some experimental results lire presented.

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A Disturbance Observer Design for Compensating Backlash at Robot Joint (로봇 관절의 백래쉬 보상을 위한 외란관측기 설계)

  • Ahn, Won-Ki;Huh, Uk-Youl
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.187-189
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    • 2006
  • In mechanical system, gear trains have backlash innately. With the presence of inherent backlash, the overall system performance is limited in many practical control systems. It has been reported that a disturbance observer has the property of effective removing disturbance and cutting measurement noise off. The plant is remodeled with modified disturbance observer to observe and compensate backlash characteristics. And this paper describes a method to design Q filter and to analyze the effects of disturbance and measurement noise to the output. It is shown that the vibration and tracking error caused by backlash were decreased and the time constant and relative degree are important factor to design Q filter.

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Estimation of Flow-induced Vibration Characteristics on Plugged Steam Generator Tube (관막음된 증기발생기 전열관의 유체유발진동 특성 평가)

  • Cho, Bong-Ho;Ryu, Ki-Wahn;Park, Chi-Yong;Park, Su-Ki
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.390.1-390
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    • 2002
  • In this study, we investigate the plugging effect on the CE type steam generator tube. The natural frequency and mode shape will be changed due to decrease of the effective mass distribution along the tube. We compared the variation of stability ratio for plugged tube with that fur unplugged one. The natural frequency increased because of removing the cooling water inside the steam generator tube, but the stability ratio decreased inversely because of changing the vibrational mode shape. We also investigated the turbulent excitation effect.

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