• Title/Summary/Keyword: Inverse Filter

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패턴인식을 위한 Off-Axis SDF Filter Off-Zxis SDF Filter for Pattern Classification

  • 임종태
    • Proceedings of the Optical Society of Korea Conference
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    • 1991.06a
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    • pp.181-184
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    • 1991
  • 본 논문에서는 off-axis 평면 기준파의 각분할(angular multiflexing) 방식과 pseudo-inverse 알고리듬에 의한 SDF 필터를 결합하여 상관기를 구성하고 상관면에서의 상관반응을 관측하여, off-axis SDF 필터가 유형분류에 유용함을 입증하고, 광상관기로의 적용가능성을 보여주고자 한다.

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Neural Network Based Disturbance Canceler with Feedback Error Learning for Nonholonomic Mobile Robots

  • Izumi, Kiyotaka;Syam, Rafiuddin;Watanabe, Keigo;Kiguchi, Kazuo
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09a
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    • pp.443-446
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    • 2003
  • Conventional disturbance rejection methods have to derive the inverse model of a system. However, the inverse model of n nonholonomic system is not unique, because an inverse it changes depending on initial conditions and desired values. A kind of internal model control (IMC) using feedback error learning is discussed for the motion control of nonholonomic mobile robots in this paper, The present method is different from a conventional IMC whose control system consists of an inverse model, a direct model and a filter. The present disturbance rejection method need not use a direct model, where the remaining two elements are composed of the same inverse model based on neural networks.

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Sparsity-constrained Extended Kalman Filter concept for damage localization and identification in mechanical structures

  • Ginsberg, Daniel;Fritzen, Claus-Peter;Loffeld, Otmar
    • Smart Structures and Systems
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    • v.21 no.6
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    • pp.741-749
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    • 2018
  • Structural health monitoring (SHM) systems are necessary to achieve smart predictive maintenance and repair planning as well as they lead to a safe operation of mechanical structures. In the context of vibration-based SHM the measured structural responses are employed to draw conclusions about the structural integrity. This usually leads to a mathematically illposed inverse problem which needs regularization. The restriction of the solution set of this inverse problem by using prior information about the damage properties is advisable to obtain meaningful solutions. Compared to the undamaged state typically only a few local stiffness changes occur while the other areas remain unchanged. This change can be described by a sparse damage parameter vector. Such a sparse vector can be identified by employing $L_1$-regularization techniques. This paper presents a novel framework for damage parameter identification by combining sparse solution techniques with an Extended Kalman Filter. In order to ensure sparsity of the damage parameter vector the measurement equation is expanded by an additional nonlinear $L_1$-minimizing observation. This fictive measurement equation accomplishes stability of the Extended Kalman Filter and leads to a sparse estimation. For verification, a proof-of-concept example on a quadratic aluminum plate is presented.

A Study on the Modified RLS Algorithm Using Orthogonal Input Vectors (직교 입력 벡터를 이용하는 수정된 RLS 알고리즘에 관한 연구)

  • Ahn, Bong Man;Kim, Kwang Woong;Ahn, Hyun Gyu;Han, Byoung Sung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.1
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    • pp.13-19
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    • 2019
  • This paper proposes an easy algorithm for finding tapped-delay-line (TDL) filter coefficients in an adaptive filter algorithm using orthogonal input signals. The proposed algorithm can be used to obtain the coefficients and errors of a TDL filter without using an inverse orthogonalization process for the orthogonal input signals. The form of the proposed algorithm in this paper has the advantages of being easy to use and similar to the familiar recursive least-squares (RLS) algorithm. In order to evaluate the proposed algorithm, system identification simulation of the $11^{th}$-order finite-impulse-response (FIR) filter was performed. It is shown that the convergence characteristics of the learning curve and the tracking ability of the coefficient vectors are similar to those of the conventional RLS analysis. Also, the derived equations and computer simulation results ensure that the proposed algorithm can be used in a similar manner to the Levinson-Durbin algorithm.

Adaptive Echo Canceller with Improved Convergence Speed (적응 반향 제거기의 수렴 속도 향상)

  • 김남선;임용훈;임종민;차일환;윤대희
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1991.10a
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    • pp.111-114
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    • 1991
  • This paper proposes an efficient adaptive echo canceller using pilot filter approach to achieve improved convergence speed. The pilot filter is an adaptive filter with only a few filter coefficients to filter the received signal for the purpose of whitening the signal. Thus the convergence speed of the main LMS-TDL filter combined with the pilot filter is improved. In the proposed echo canceller, an adaptive lattice predictor as the pilot filter is used and its inverse filter is used to equalize the distorted near end talker signal. Simulation results for colored signal show that the convergence speed of the proposed echo cancellation algorithm is faster than that of the conventional LMS-TDL echo cancellation algorithm.

Optimal Adaptive Filter Design of M-wave Elimination for Treating Tooth Grinding

  • Yeom, Hojun
    • International journal of advanced smart convergence
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    • v.5 no.4
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    • pp.66-70
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    • 2016
  • When tooth grinding occurs, electrical stimulation is given at the same time, and tooth grinding stops on such stimulation. Electromyography signals are used as control signals of electrical stimulation to disturb tooth grinding. However because of the electrical stimulation, the M-waves are generated and mixed with spontaneous electromyogram. In this study, we designed an optimal filter to remove M-wave and conserve spontaneous electromyogram simultaneously. The inverse power method (IPM) showed that the optimal filter coefficient is the eigenvector corresponding to the minimum eigenvalue of the input covariance matrix. In order to evaluate the performance of the optimal filter, we compared using a conventional band pass filter and adaptive filter using least mean square algorithm. The experimental results show that the optimal filter can effectively remove the M-wave compared to the previously studied prediction error filter.

AN IMPLICATIVE FILTER OF BE-ALGEBRAS IN CONNECTION WITH CUBIC INTUITIONISTIC FUZZY SETS

  • Rajab Ali, Borzooei;Hee Sik, Kim;Young Bae, Jun;Sun Shin, Ahn
    • Honam Mathematical Journal
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    • v.44 no.4
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    • pp.535-559
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    • 2022
  • The notions of cubic intuitionistic fuzzy set to filters and implicative filters of BE-algebras are introduced. Relations between cubic intuitionistic fuzzy filters with cubic intuitionistic fuzzy implicative filters of BE-algebras are investigated. The homomorphic image and inverse image of cubic intuitionistic fuzzy filters are studied and some related properties are investigated. Also, the product of cubic intuitionistic fuzzy subalgebras (implicative filters) of BE-algebras are investigated.

A Study on the Synthesis of Dielectric Constant Potential for Arbitrary Inverse Scattering Pattern Using an Iterative Sampling Method (반복 샘플링법을 사용한 임의 역산란 패턴을 위한 유전율 포텐셜 합성에 관한 연구)

  • 남준석;박의준
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.10
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    • pp.150-158
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    • 2003
  • In the beam pattern synthesis problem using line source, the relationship between source distribution function and beam pattern may be represented by Fourier transform pair. In this paper, a general method to synthesize the line source distribution for a desired lobe-like beam pattern is presented by developing the nonlinear inversion method based on an iterative sampling technique. This method can be applied to the synthesis of continuously distributed dielectric constants satisfying the desired inverse scattering coefficient patterns when illuminating by TE-polarized and TM-polarized plane waves to arbitrary dielectric material. Furthermore this method can also be applied to the synthesis of transmission line with arbitrary reflection coefficient patterns. Some bandstop spatial filter and dispersive transmission line filter are illustrated for generality.

Characteristic of Inverse wavelet transform and Multi bank system (연속 웨이브렛 역변환의 특성 및 멀티 뱅크 시스템)

  • Kim Tae-hyung;Yoon Dong-han
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.2
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    • pp.229-236
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    • 2005
  • This paper is contribute to Inverse continuous wavelets transform(ICWT) which permits to determine real 'time-scale' plan. The application of ICWT is not yet represented because of the numerical difficulty. If the signal can be reconstructed stably by ICWT, the multi scale filter bank system which composed by analysis and synthesis process can be designed. In this work, we represent the ICWT which leads to nearly perfect reconstruction of signal and the multi-scale filter bank system.