• 한국산학기술학회논문지
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• 제13권8호
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• pp.3647-3653
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• 2012

능동 소음제어 시스템에 사용되는 IIR 필터 구조는 구조적으로 안정성이 보장되어야 하며 이는 분모 전달 함수의 근이 단위원 내부에 존재하여야 한다. 따라서 이를 결정하는 제어 필터의 계수의 적절한 조정이 중요해 진다. 본 논문에서는 적응과정에서 불안정할 우려가 있는 IIR 필터 구조를 가지는 Filtered_U LMS 알고리즘에 안정화 알고리즘과 수렴속도 향상을 위한 퍼지논리를 이용한 수렴계수 계산 알고리즘을 제안하였다. 제안한 알고리즘이 FIR 필터 구조 알고리즘보다 계산량이 적고 수렴특성이 우수함을 시뮬레이션을 통하여 보였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.239-245
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• 2000

Adaptive bang-bang control algorithm has been proposed by the authors to improve peak response reduction of building structures under unexpected large earthquake. At the previous research, control performance of the proposed algorithm was experimentally confirmed by using a I-DOF test structure. As an extended research, performance tests on a multi-DOF model structure have been conducted to prove the usefulness of the adaptive bang-bang control algorithm using a hydraulic AMD. It is confirmed that the proposed adaptive bang-bang algorithm is applicable to suppress the vibration of multi-DOF structures subject to severe external excitations.

• International Journal of Aeronautical and Space Sciences
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• 제2권2호
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• pp.19-27
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• 2001

This research attempts to find an active control strategy which reduces acoustic power and acoustic energy in lightly-damped enclosed sound field such as a vehicle compartment or an operating room of heavy industrial machinery. An active control strategy, which takes into consideration of the acoustic radiation power of the source as a cost function, is formulated and examined to find capability of reducing noise. An adaptive filtering algorithm for sound power control is suggested and implemented to control lightly-damped sound field. To verify the method, sound power based active noise control algorithm was implemented on a rectangular box with lightly-damped wall, and popular acoustic energy based control with modal coupling reduction was performed to compare the noise reduction performance. It was shown that a total sound power based strategy provides a practical mean for global noise reduction for lightly damped sound field.

• 조명전기설비학회논문지
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• 제15권5호
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• pp.34-40
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• 2001

본 논문에서는 화력발전소 보일러 운전원 근무실 소음제어를 위하여 협대역 능동소음 제어시스템을 제안하였다. 제안된 시스템은 기준입력으로 구형파를 사용하여 기본파는 물론 고조파까지 한꺼번에 제어할 수 있게 하였으며, adjoint LMS 알고리즘을 사용하여 기존의 filtered-X LMS 알고리즘을 사용한 경우보다 계산량을 줄였다. 컴퓨터 시뮬레이션 결과, 기존의 광대역 능동소음 제어시스템에 비해 훨씬 작은 자수의 적응 필터를 사용하였으나, 더 우수한 특성을 보였다.

• 대한기계학회논문집A
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• 제21권2호
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• pp.281-287
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• 1997

In the conventional inverse modeling method for on-line modeling of the secondary path transfer function, the signal to noise ratio between the arbitrary random signal and the plant noise have to keep at -10 - -20 dB. For these reasons, the modeling can't be exactly implemented by the conventional method alone and the convergence time for modeling becomes too long. In this study, by combining the conventional inverse modeling method with an adaptive line enhancer, or with an adaptive noise canceller, a rigorous transfer functions of secondary path modeling and the control of a primary noise have been implemented simultaneously.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.301-306
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• 2011

In this paper, active noise barriers for attenuation of road noise are proposed. multi-channel audio systems, DAQ part and high performance DSP H/W were designed. Active noise control firmware programs were implemented for multi-channel off-line/on-line estimation methods for secondary path transfer functions and FIR/IIR filter structure are used main noise control algorithms. To evaluate performance of proposed systems, the experiments were performed in an active noise barrier test bed for various noise cases.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.299-301
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• 1992

The adaptive active noise control algorithm for duct noise attenuation is considered. A new algorithm to estimate the secondary path transfer function using multiple models is presented. The computational burden of the proposed algorithm is much smaller than the existing methods, so it could be applied to the multi-channel cases. Computer simulations were done to show the effectiveness of the proposed algorithm in a duct case.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.775-780
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• 1994

A new simple method to formulate the adaptive algorithm to control the coefficients of FIR filter is introduced. The filter is used in the active noise control system. The introduced algorithm includes the LMS algorithm as a special case. The validity of the theoretical result is confirmed by the computer simulation.

• 소음진동
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• 제9권2호
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• pp.265-272
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• 1999

A LMS algorithms has been widely used for an adaptive filter algorithm in active noise control systems. But this algorithm has poor convergence and it is very difficult to select optimal convergence parameters in this algorithm. In this paper, a fuzzy LMS algorithm where the convergence parameters are computed using a fuzzy logic controller was proposed. A proposed algorithm was applied to active noise control system in HVAC(central Heating Ventilation and Air Conditioning) ducts. The experimental ducts and experimental apparatus were designed and manufactured for experiments, and the modelling of the experimental ducts was also performed for computer simulations. Computer simulations and experiments were performed to show the effectiveness of a proposed algorithm.

• Journal of information and communication convergence engineering
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• 제9권6호
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• pp.763-768
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• 2011

Image denoising is a lively research field. Today the researches are focus on the wavelet domain especially using wavelet threshold method. We proposed an adaptive threshold method which considering the characteristic of different sub-band, the method is adaptive to each sub-band. Experiment results show that the proposed method extracts white Gaussian noise from original signals in each step scale and eliminates the noise effectively. In addition, the method also preserves the detail information of the original image, obtaining superior quality image with higher peak signal to noise ratio(PSNR).