• 제목/요약/키워드: Active function

검색결과 1,900건 처리시간 0.027초

가속도 되먹임 제어기를 이용한 양단지지보의 능동제어 (Active Control of Clamped Beams Using Acceleration Feedback Controllers)

  • 신창주;홍진숙;정의봉;정상우
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2010년도 추계학술대회 논문집
    • /
    • pp.101-109
    • /
    • 2010
  • This paper reports active control of clamped beams using acceleration feedback controllers (AF). The equations of motion of clamped beam under force and moment pairs were derived and the equations of AF controllers were formulated. The effect of the parameters - gain and damping ratio - of the AF controllers on the open loop transfer function was investigated mainly in terms of the system stability. Increasing the gain of the AF controller tuned at a mode, the magnitude of the open loop transfer function is increased at all frequencies. The increase of the damping ratio of the AF controller leads to decrease the magnitude of the open loop transfer function and modifies its phase characteristics to be more stable. Three AF controllers connected in parallel were then proposed. Each AF controller is tuned at the $2^{nd}$, $3^{rd}$ and $4^{th}$ modes, respectively. Their parameters were determined to remain the system to be stable based on the results of the parametric study. A significant reduction in vibration at the 3 modes can be obtained.

  • PDF

도로환경 정온화의 실시간 적용을 위한 Co-LMS 알고리즘의 특성 고찰 (A Study on the Co-LMS Algorithm Characteristics of Real-time Applicants for Road Environment Calming)

  • 문학룡;손진근
    • 전기학회논문지P
    • /
    • 제63권3호
    • /
    • pp.157-162
    • /
    • 2014
  • The active noise control(ANC) method for noise problems solution generally uses filtered-X LMS algorithms. However, Filtered-X LMS algorithms were mainly used but these had a limitation that had to measure a transfer function of secondary noise path. However, newly proposed correlation-LMS algorithms have slightly much calculation and are minutely behind performance, these have a advantage not in measuring transfer function onerously so that we can easily adapt these in real time. Thus Co-LMS algorithm was developed to improve the real-time implementation performance under the variable input noise such as road noise environment. In this paper, the performance of the Co-LMS is presented in comparison with that of the Filtered-X LMS algorithm. Simulation results show that active noise control using Co-LMS have slightly much calculation and are minutely behind performance, these have a advantage not in measuring transfer function onerously so that we can easily adapt these in real time.

가속도 되먹임 제어기를 이용한 양단지지보의 능동 제어 (Active Control of Clamped Beams using Acceleration Feedback Controllers)

  • 신창주;홍진숙;정의봉;정상우
    • 한국소음진동공학회논문집
    • /
    • 제20권12호
    • /
    • pp.1190-1199
    • /
    • 2010
  • This paper reports active control of clamped beams using acceleration feedback controllers (AF). The equations of motion of clamped beam under force and moment pairs were derived and the equations of AF controllers were formulated. The effect of the parameters - gain and damping ratio - of the AF controllers on the open loop transfer function was investigated mainly in terms of the system stability. Increasing the gain of the AF controller tuned at a mode, the magnitude of the open loop transfer function is increased at all frequencies. The increase of the damping ratio of the AF controller leads to decrease the magnitude of the open loop transfer function and modifies its phase characteristics to be more stable. Three AF controllers connected in parallel were then proposed. Each AF controller is tuned at the 2nd, 3rd and 4th modes, respectively. Their parameters were determined to remain the system to be stable based on the results of the parametric study. A significant reduction in vibration at the 3 modes can be obtained.

이동 애드혹 네트워크에서 신뢰성 향상을 위한 액티브 기반연구 (The Study Active-based for Improvement of Reliablity In Mobile Ad-hoc Network)

  • 박경배;강경인;유재휘;김진용
    • 한국컴퓨터정보학회논문지
    • /
    • 제7권4호
    • /
    • pp.188-198
    • /
    • 2002
  • 본 논문에서는 이동 애드혹 네트워크에서 신뢰성 향상을 위한 액티브 네트워크를 제안하였다. 제안된 알고리즘에서는 DSR을 기본 프로토콜로서 액티브네트워크를 구성하였고, 송수신 노드를 액티브 노드로서 이용하였다. 신뢰성 향상을 위해 송신노드는 최근 보낸 데이터를 저장할 임시 버퍼를 생성한 후 수신노드의 요구에 의해 데이터 재전송을 수행하며 수신노드 당 흐름관리를 할 수 있는 기능을 추가하여 송신 액티브노드로 기능을 변경하였다. 수신노드는 손실된 데이터에 대한 재 전송요구와 흐름제어 기능을 추가하는 수신 액티브노드로 기능을 변경하였다. 그 결과로서, 제안된 액티브 노드는 움직임이 적은 이동 애드혹 네트워크에서는 100[%]에 근접하는 신뢰성을 보였고, 움직임이 많은 이동 애드혹 네트워크에서 보다 평균 3.5737% 증가한 95%의 데이터 수신율을 보장하였다.

  • PDF

Co-FXLMS 알고리듬을 이용한 능동소음제어 성능의 향상 (Performance Improvement of Active Noise Control Using Co-FXLMS Algorithm)

  • 권오철;이경태;박상길;이정윤;오재응
    • 한국소음진동공학회논문집
    • /
    • 제18권3호
    • /
    • pp.284-292
    • /
    • 2008
  • The active control technique mostly uses the least-mean-square(LMS) algorithm, because the LMS algorithm can easily obtain the complex transfer function in real-time, particularly when the Filtered-X LMS(FXLMS) algorithm is applied to an active noise control(ANC) system. However, FXLMS algorithm has the demerit that stability of the control is decreased when the step size become larger but the convergence speed is faster because the step size of FXLMS algorithm is fixed. As a result, the system has higher probability which the divergence occurs. Thus the Co-FXLMS algorithm was developed to solve this problem. The Co-FXLMS algorithm is realized by using an estimate of the cross correlation between the adaptation error and the filtered input signal to control the step size. In this paper, the performance of the Co-FXLMS algorithm is presented in comparison with the FXLMS algorithm. Simulation and experimental results show that active noise control using Co-FXLMS is effective in reducing the noise in duct system.

에너지 최소화 기반 능동형태 모델을 이용한 입술 윤곽선 추출 (Lip Contour Extraction Using Active Shape Model Based on Energy Minimization)

  • 장경식
    • 한국정보통신학회논문지
    • /
    • 제10권10호
    • /
    • pp.1891-1896
    • /
    • 2006
  • 이 논문에서는 능동형태 모델을 개선하여 입술의 형태를 효과적으로 추출하는 방법을 제안하였다. 입술의 형태변형은 능동형태 모델에 기반을 둔 통계적 형태 변형 모델을 사용하여 표현하였다. 능동형태 모델에서 각 점은 지엽적인 정보인 프로파일을 기반으로 독립적으로 이동하기 때문에 많은 오류가 발생할 수 있다. 전역적인 정보를 사용하기 위하여 이 논문에서는 능동윤곽선 모델에서 사용하는 것과 유사한 에너지 함수를 정의하고 전체 에너지가 최소화되는 위치로 점들이 이동하게 하였다. Tulip 1 데이터 베이스에 있는 입술 영상을 대상으로 실험한 결과, 제안한 방법이 기존 방법보다 실제 형태에 가깝게 입술을 추출하였다.

Co-FXLMS 알고리듬을 이용한 능동소음제어 성능의 향상 (Performance Improvement of Active Noise Control Using Co-FXLMS Algorithm)

  • 이해진;권오철;이정윤;오재응
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2007년도 춘계학술대회논문집
    • /
    • pp.598-603
    • /
    • 2007
  • The active control technique mostly uses the Least-Mean-Square (LMS) algorithm, because the LMS algorithm can easily obtain the complex transfer function in real-time, particularly when the Filtered-X LMS (FXLMS) algorithm is applied to an active noise control (ANC) system. However, FXLMS algorithm has the demerit that stability of the control is decreased when the step size become larger but the convergence speed is faster because the step size of FXLMS algorithm is fixed. As a result, the system has higher probability which the divergence occurs. Thus the Co-FXLMS algorithm was developed to solve this problem. The Co-FXLMS algorithm is realized by using an estimate of the cross correlation between the adaptation error and the filtered input signal to control the step size. In this paper, the performance of the Co-FXLMS algorithm is presented in comparison with the FXLMS algorithm. Simulation results show that active noise control using Co-FXLMS is effective in reducing the noise in duct system.

  • PDF

무부하 압축기에 의한 냉장고 기계실 소음의 능동제어 (Active Control of Noise Transmitted through Ventilation Openings of the Machinery Room of Refrigerator)

  • 구정모;정의봉;김태훈;홍진숙
    • 한국소음진동공학회논문집
    • /
    • 제26권4호
    • /
    • pp.475-482
    • /
    • 2016
  • The active control of noise generated by the compressor and transmitted out of the machine room through the windows is implemented based on the FIR filter. The machine room contains most of noise sources of electric home appliances, air-conditioners and refrigerators, for example. To actively reduce the noise from the machinery room. In this paper, the transfer function of the controller for minimization of the acoustic power transmitted through the windows is mathematically formulated. The transfer functions required for implementation of the active controller are the measured. The measurements are conducted in this initial stage under the operation of the compressor with no load. For improvement of the reliability of the transfer function of the compressor to the acoustic power, additional operational measurements are performed. The real time controller is implemented based on the FIR filter using the measured transfer functions and the performance of the active controller is estimated. Control performance is measured about 3 dB ~ 10 dB in reduction of the sound power at the peaks of the compressor noise.

Systematic analysis of the pharmacological function of Schisandra as a potential exercise supplement

  • Hong, Bok Sil;Baek, Suji;Kim, Myoung-Ryu;Park, Sun Mi;Kim, Bom Sahn;Kim, Jisu;Lee, Kang Pa
    • 운동영양학회지
    • /
    • 제25권4호
    • /
    • pp.38-44
    • /
    • 2021
  • [Purpose] Exercise can prevent conditions such as atrophy and degenerative brain diseases. However, owing to individual differences in athletic ability, exercise supplements can be used to improve a person's exercise capacity. Schisandra chinensis (SC) is a natural product with various physiologically active effects. In this study, we analyzed SC using a pharmacological network and determined whether it could be used as an exercise supplement. [Methods] The active compounds of SC and target genes were identified using the Traditional Chinese Medicine Database and Analysis Platform (TCMSP). The active compound and target genes were selected based on pharmacokinetic (PK) conditions (oral bioavailability (OB) ≥ 30%, Caco-2 permeability (Caco-2) ≥ -0.4, and drug-likeness (DL) ≥ 0.18). Gene ontology (GO) was analyzed using the Cytoscape software. [Results] Eight active compounds were identified according to the PK conditions. Twenty-one target genes were identified after excluding duplicates in the eight active compounds. The top 10 GOs were analyzed using GO-biological process analysis. GO was subsequently divided into three representative categories: postsynaptic neurotransmitter receptor activity (53.85%), an intracellular steroid hormone receptor signaling pathway (36.46%), and endopeptidase activity (10%). SC is related to immune function. [Conclusion] According to the GO analysis, SC plays a role in immunity and inflammation, promotes liver metabolism, improves fatigue, and regulates the function of steroid receptors. Therefore, we suggest SC as an exercise supplement with nutritional and anti-fatigue benefits.