• 한국음향학회:학술대회논문집
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• 한국음향학회 1987년도 학술발표회 논문집
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• pp.58-60
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• 1987

In this paper, we investigate an infinite impulse response adaptive digital filter based on the nonlinear least-squares algorithm, and compare its convergence speed to that of a self-orthogonalizing IIR ADF which is known to have fastest convergence. By simulation, it is shown that the NLS IIR ADF converges faster than other known IIR ADF's, especially for a low-order case.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.866-870
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• 1989

Direct application of adaptive algorithm to the actual I/O is not a good strategy. The importance of using a kind of filter for estimation or control is strongly recommended. Simple pre-filtering method and pseudo-plant method is introduced. And, the properties of each methods are compared by analysis and/or simulations. A guideline for the choice of filters are proposed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2087-2089
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• 2003

The presence of narrowband interference (NBI) in Direct-sequence code division multiple access (DS/CDMA) systems is an inevitable problem when the interference is strong enough. The improvement in the system performance employs by adaptive narrowband interference suppression techniques. Basically there have been two types of method for narrowband interference suppression estimator/subtracter approaches and transform domain approaches. In this paper the focus is on the type of estimator/subtracter approaches. However, the binary direct sequence (DS) signal, that acts as noise in the prediction process is highly non-Gaussian. The case of a Gaussian interferer with known in an autoregressive (AR) signal or a digital signal and also in a sinusoidal signal (Tone) that included in is paper. The proposed NBI suppression is presence in an adaptive IIR notch filter for lattice structure and more powerful by using a variable step-size algorithm. The simulation results show that the proposed algorithm can significantly increase the convergence rate and improved system performance when compare with adaptive least mean square algorithm (LMS).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2555-2557
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• 2001

The adaptive IIR filters is more effective than adaptive FIR filters which have the same order of IIR filters. But the IIR filters may have stability problems especially when the adaptive algorithm is not converged. In this paper, a stabilizing procedure for adaptive IIR filters is proposed, and computer simulation is performed to show the effectiveness of proposed schemes.

• The Journal of the Acoustical Society of Korea
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• 제17권2E호
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• pp.10-15
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• 1998

Application of the Filtered-X LMS adaptive filter to active noise cancellation requires to estimate the transfer characteristics between the output and the error signal of the adaptive canceler. In this paper, we derive an adaptive cancellation algorithm and analyze is convergence behavior when the acoustic noise is assumed to consist of multiple sinusoids. The results of the convergence analysis of the Filtered-X LMS algorithm indicate that the effects of parameter estimation inaccuracy on the convergence behavior of the algorithm are characterize by two distinct components : Phase estimation error and estimated magnitude. In particular, the convergence of the Filtered-X LMS algorithm is show to be strongly affected by the accuracy of the phase response estimate. Simulation results of the algorithm are presented which support the theoretical convergence analysis.

• 대한전자공학회논문지SD
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• 제41권9호
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• pp.65-71
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• 2004

본 논문은 휴대폰의 자동차 핸즈프리를 위한 음향반향제거기의 설계 및 구현에 관한 것이다. 이를 구현하기 위해 효율적인 적응 알고리즘의 개발과 VHDL 회로설계, 그리고 테스트 보드 제작 등을 수행하였다. 적응 알고리즘은 간단하고 안정적이며 수렴속도가 빠른 새로운 S-LMS 알고리즘을 사용하였다 음향반향제거기는 15-bit, 128-tap 회로구조로서 50,000 게이트급 FPGA에 구현하였다. 그리고 회로동작을 검증하기 위하여 보드를 제작하였는데, 2개의 CODEC과 제어입력용 DIP 스위치 및 출력표시용 LED 등이 포함되어 있다. 백색 가우스잡음을 사용하여 시험한 결과, 구현된 회로의 ERLE는 최대 30dB의 반향제거 성능을 나타내는 것으로 확인되었다.

• 한국정보통신학회논문지
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• 제4권3호
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• pp.653-660
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• 2000

본 논문에서는 대역확산 통신을 위하여 웨이브렛 패킷 영역에서 다중적응필터뱅크를 이용하여 간섭신호를 제거할 수 있는 적응간섭제거기를 제안하고 Monte-Carlo 시뮬레이션을 이용하여 AWGN과 간섭채널에서 LMS와 RLS 적응알고리즘이 적용된 간섭제거기에 따른 대역확산통신시스템의 성능을 분석하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.366-366
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• 2000

In this paper, an adaptive neuro-fuzzy filter using the conditional fuzzy c-means(CFCM) methods is proposed. Usualy, the number of fuzzy rules exponentially increases by applying the grid partitioning of the input space, in conventional adaptive neuro-fuzzy inference system(ANFIS) approaches. In order to solve this problem, CFCM method is adopted to render the clusters which represent the given input and output data. Parameter identification is performed by hybrid learning using back-propagation algorithm and total least square(TLS) method. Finally, we applied the proposed method to the nonlinear channel equalization problem and obtained a better performance than previous works.

• IEIE Transactions on Smart Processing and Computing
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• 제3권5호
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• pp.267-270
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• 2014

This paper presents the comparative performance of an adaptive FIR filter for a Delayed LMS algorithm. The delayed error signal was used to obtain a Delayed LMS algorithm to allow efficient pipelining for achieving a small critical path and area efficient implementation. This paper presents hardware efficient results (device utilization parameters) and power consumed. The FPGA families (Artix-7, Virtex-7, and Kintex-7) for a low voltage perspective are shown. The synthesis results showed that the artix-7 CMOS family achieves the lowest power consumption of 1.118 mW with 83.18 % device utilization. Different Precision strategies, such as the speed optimization and power optimization, were imposed to achieve these results. The algorithm was implemented using MATLAB (2013b) and synthesized on the Leonardo spectrum.

• 한국멀티미디어학회논문지
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• 제4권3호
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• pp.222-229
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• 2001

하나의 정지영상 내에서 공간적으로 인접한 화소들을 사용하여 디지털 영상을 확대하기 위한 많은 방법들이 제안되고 있다. 본 논문에서는 보간 화소점에 인접한 화소들의 상관도에 따라 상대적으로 우수한 성능을 보여주고 있는 pseudomedian 필터의 부위도우 설정을 가변적으로 변화하여 윤곽 정보의 재현성을 개선한 디지털 영상 확대방법을 제안하였다. 제안한 알고리즘은 Visual C++을 이용하여 시뮬레이션하였고, PSNR을 통하여 보간 알고리즘의 성능을 검증하였다. 최종적으로, 제안한 알고리즘인 적응형 pseudomedian 필터는 synopsys VHDL을 사용하여 설계하였다