• Title/Summary/Keyword: Adaptive algorithm

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A Study on the Algorithm for the Frequency Domanin-Adaptive Filter (주파수 영역-적응 필터 알고리즘에 관한 연구)

  • 신윤기;이종옥
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.22 no.2
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    • pp.18-24
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    • 1985
  • Above certain filter order, the frequency domain -adaptive filter is superior to the time domain-adaptive filter in computational complexity. In this paper a new type algorithm, $\mu$-FLMs algorithm, is proposed for the frequency domain- adaptive filter and the characteristics of the proposed algorithm is compared with that of the time domain- adaptive filter algorithm($\mu$-FLMS algorithm). The simulation results showed that under the same convergence rate , the frequency domain-adaptive filter is efficient in compu tational burden.

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Hyperstable Adaptive Recursive Filter with an Adaptive Compensator (適應 補償器를 채용한 超安定性 適應 循環 필터)

  • Yoon, Byung-Woo;Shin, Yoon-Ki
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.3
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    • pp.145-155
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    • 1990
  • In this paper, an adaptive Infinite Impulse Response (IIR) filter algorithm using output error method, which prevents poles of a system transfer function from being out of unit circle, is proposed, and it is proved that the proposed algorithm always satisfies hyperstability. The proposed algorithm is applied to an Adaptive Noise Canceller (ANC), and compared with a Least Square (LS) method adaptive IIR filter algorithm and an adaptive Finite Inpulse Response (FIR) filter algorithm. As a result, the validity of the proposed algorithm is proved.

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A Square Root Normalized LMS Algorithm for Adaptive Identification with Non-Stationary Inputs

  • Alouane Monia Turki-Hadj
    • Journal of Communications and Networks
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    • v.9 no.1
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    • pp.18-27
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    • 2007
  • The conventional normalized least mean square (NLMS) algorithm is the most widely used for adaptive identification within a non-stationary input context. The convergence of the NLMS algorithm is independent of environmental changes. However, its steady state performance is impaired during input sequences with low dynamics. In this paper, we propose a new NLMS algorithm which is, in the steady state, insensitive to the time variations of the input dynamics. The square soot (SR)-NLMS algorithm is based on a normalization of the LMS adaptive filter input by the Euclidean norm of the tap-input. The tap-input power of the SR-NLMS adaptive filter is then equal to one even during sequences with low dynamics. Therefore, the amplification of the observation noise power by the tap-input power is cancelled in the misadjustment time evolution. The harmful effect of the low dynamics input sequences, on the steady state performance of the LMS adaptive filter are then reduced. In addition, the square root normalized input is more stationary than the base input. Therefore, the robustness of LMS adaptive filter with respect to the input non stationarity is enhanced. A performance analysis of the first- and the second-order statistic behavior of the proposed SR-NLMS adaptive filter is carried out. In particular, an analytical expression of the step size ensuring stability and mean convergence is derived. In addition, the results of an experimental study demonstrating the good performance of the SR-NLMS algorithm are given. A comparison of these results with those obtained from a standard NLMS algorithm, is performed. It is shown that, within a non-stationary input context, the SR-NLMS algorithm exhibits better performance than the NLMS algorithm.

Block LMS-Based Adaptive Beamforming Algorithm for Smart Antenna (스마트 안테나를 위한 블록 LMS 기반 적응형 빔형성 알고리즘)

  • O, Jeong-Geun;Kim, Seong-Hun;Yu, Gwan-Ho
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.689-692
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    • 2003
  • In this paper, we propose an adaptive beamforming algorithm for array antenna. The proposed beamforming algorithm, based on Block LMS (Block - Least Mean Squares) algorithm, has a variable step size from coefficient update. This method shows some advantages that the convergence speed is fast and the calculation time can reduced using a block LMS algorithm from frequency domain. As the adaptive parameter approaches a stationary state, it could reduce the number of filter coefficient update with the help of various step size. In this paper we compared the efficiency of the proposed algorithm with a standard LMS algorithm which is a representative method of adaptive beamforming.

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Adaptive Noise Reduction on the Frequency Domain using the Sign Algorithm.

  • Lee, Jae-Kyung;Yoon, Dal-Hwan;Min, Seung-Gi
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.57-60
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    • 2003
  • We have proposed the adaptive noise reduction algorithm using the MDFT. The algorithm proposed use the linear prediction coefficients of the AR method based on Sign algorithm that is the modified LMS instead of the least mean square(LMS). The signals with a random noise tracking performance are examined through computer simulations and confirmed that the high speed adaptive noise reduction processing system is realized with rapid convergence.

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Deterministic Disturbance Rejection for Model Reference Adaptive Control (결정론적 외란에 대한 적응제어 알고리즘의 연구)

  • Kim, Yong-Sei;Feng, G.;Lee, Kwon-S.
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.341-344
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    • 1993
  • This paper presents the general MRAC algorithm design, it's real time implementation and investigates the effect of purely deterministic disturbances to adaptive control algorithm. The design of adaptive control algorithm to reject the disturbances properly is also presented. In real time application, adaptive control algorithm is considered to investigate its performance by using DC motor. Disturbance rejection algorithm is investigated in simulation.

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A Study on Fast Convergence Algorithm of Block Adaptive Filter in Frequency Domain (주파수 영역에서 블럭적응 필터의 고속 수렴 알고리즘에 관한 연구)

  • 강철호;조해남
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.10 no.6
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    • pp.308-316
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    • 1985
  • A new implementation of Block Adaptive filter in frequency domain is presented in this paper. Block digital filtering involves the calculation of a block or finite set of filter out put from a block of input values. A fast convergence algorithm of block adaptive filter is developed using Gordar theory and compared with the performance results of Satio algorithm and BLMS algorithm. Form the result we can be shown that the convergence state of given algorithm is not only faster than BLMS algorithm but also the resulting convergence error is less than the convergence error of Satio algorithm.

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A Study of Character Recognition using Adaptive Algorithm at the Car License Plate (적응 알고리즘을 이용한 자동차 번호판 인식 시스템 개발에 대한 연구)

  • Jang, Seung-Ju
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.10
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    • pp.3155-3163
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    • 2000
  • In the recognitionsystem of car license plate, it is very important to extract the character from the license plate and recognize the extrated character. In this paper, I use the adaptive algorithm to recognize the charactor of licensse plate image. The adaptive algorithm is compounded of thinning algorithm template matching,algarthm, vector algorithm and so on. The adaptive algorithm was used to recognize the character from license image. In the result of expenment, character recognition is about up to 90% with the adaptive algorithm for the character region.

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Directional Interpolation Based on Improved Adaptive Residual Interpolation for Image Demosaicking

  • Liu, Chenbo
    • Journal of Information Processing Systems
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    • v.16 no.6
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    • pp.1479-1494
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    • 2020
  • As an important part of image processing, image demosaicking has been widely researched. It is especially necessary to propose an efficient interpolation algorithm with good visual quality and performance. To improve the limitations of residual interpolation (RI), based on RI algorithm, minimalized-Laplacian RI (MLRI), and iterative RI (IRI), this paper focuses on adaptive RI (ARI) and proposes an improved ARI (IARI) algorithm which obtains more distinct R, G, and B colors in the images. The proposed scheme fully considers the brightness information and edge information of the image. Since the ARI algorithm is not completely adaptive, IARI algorithm executes ARI algorithm twice on R and B components according to the directional difference, which surely achieves an adaptive algorithm for all color components. Experimental results show that the improved method has better performance than other four existing methods both in subjective assessment and objective assessment, especially in the complex edge area and color brightness recovery.

Design of Adaptive Beamforming Antenna using EDS Algorithm (EDS 알고리즘을 이용한 적응형 빔형성 안테나 설계)

  • Kim, Sung-Hun;Oh, Jung-Keun;You, Kwan-Ho
    • Proceedings of the KIEE Conference
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    • 2004.05a
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    • pp.56-58
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    • 2004
  • In this paper, we propose an adaptive beamforming algorithm for array antenna. The proposed beamforming algorithm is based on EDS (Euclidean Direction Search) algorithm. Generally LMS algorithm has a much slower rate of convergence, but its low computational complexity and robustness make it a representative method of adaptive beamforming. Although the RLS algorithm is known for its fast convergence to the optimal Wiener solution, it still suffers from high computational complexity and poor performance. The proposed EDS algorithm has a rapid convergence better than LMS algorithm, and has a computational more simple complexity than RLS algorithm. In this paper we compared the efficiency of the EDS algorithm with a standard LMS algorithm.

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