• Title/Summary/Keyword: Gram-Schmidt

검색결과 71건 처리시간 0.046초

피드백 구조의 적응 RF 필터를 이용한 EEG 신호 예측 (EEG Signal Prediction Using Feedback Structured Adaptive RF Filter)

  • 김현술;우용호;김택수;최윤호;박상희
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1995년도 추계학술대회
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    • pp.282-285
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    • 1995
  • In this paper, we present a feedback structured adaptive RF filter based on the recursive modified Gram-Schmidt algorithm for short-term prediction of EEG signal. And the performance of this proposed filter is compared with those of linear AR model, RF filter, Volterra filter and RBF neural network as single-step prediction and multi-step prediction. The results show the superiority of this proposed filter in prediction of EEG signals.

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An Application of a Parallel Algorithm on an Image Recognition

  • Baik, Ran
    • Journal of Multimedia Information System
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    • 제4권4호
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    • pp.219-224
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    • 2017
  • This paper is to introduce an application of face recognition algorithm in parallel. We have experiments of 25 images with different motions and simulated the image recognitions; grouping of the image vectors, image normalization, calculating average image vectors, etc. We also discuss an analysis of the related eigen-image vectors and a parallel algorithm. To develop the parallel algorithm, we propose a new type of initial matrices for eigenvalue problem. If A is a symmetric matrix, initial matrices for eigen value problem are investigated: the "optimal" one, which minimize ${\parallel}C-A{\parallel}_F$ and the "super optimal", which minimize ${\parallel}I-C^{-1}A{\parallel}_F$. In this paper, we present a general new approach to the design of an initial matrices to solving eigenvalue problem based on the new optimal investigating C with preserving the characteristic of the given matrix A. Fast all resulting can be inverted via fast transform algorithms with O(N log N) operations.

Free vibration analysis of elliptic and circular plates having rectangular orthotropy

  • Chakraverty, S.;Petyt, M.
    • Structural Engineering and Mechanics
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    • 제7권1호
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    • pp.53-67
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    • 1999
  • The natural frequencies and modes of free vibration of specially orthotropic elliptic and circular plates are analysed using the Rayleigh-Ritz method. The assumed functions used are two-dimensional boundary characteristic orthogonal polynomials which are generated using the Gram-Schmidt orthogonalization procedure. The first five natural frequencies are reported here for various values of aspect ratio of the ellipse. Results are given for various boundary conditions at the edges i.e., the boundary may be any of clamped, simply-supported or fret. Numerical results are presented here for several orthotropic material properties. For rectilinear orthotropic circular plates, a few results are available in the existing literature, which are compared with the present results and are found to be in good agreement.

입력 신호의 연속적인 직교화를 통한 LMS 알고리즘의 수렴 속도 향상 (Convergence Acceleration of the LMS Algorithm Using Successive Data Orthogonalization)

  • 신현출
    • 대한전자공학회논문지SP
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    • 제45권2호
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    • pp.90-94
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    • 2008
  • 적응 필터의 입력 신호의 상관도 (correlation)가 클 경우 LMS 알고리즘의 수렴 속도는 상당히 느려지게 된다. 본 논문에서는 입력 신호의 상관도가 높은 상황에서 수렴 속도를 향상시킬 수 있는 적응 필터링 알고리즘을 제안한다. 입력 신호에 대하여 직교성을 가지도록 변환을 인위적으로 가하여 LMS 알고리즘의 한계를 극복한다. 제안한 알고리즘의 성능 향상은 시스템식별 모델을 통하여 그 수렴 속도의 개선을 확인하며 또한 시변 환경 하에서 적응 필터의 시변 추적 능력을 통해 보여 진다.

등가의 Wiener-Hopf 방정식에 관한 연구 (Research on an Equivalent Wiener-Hopf Equation)

  • 안봉만;조주필
    • 한국통신학회논문지
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    • 제33권9C호
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    • pp.743-748
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    • 2008
  • 본 논문은 평균 자승 측면에서 직교 입력 신호에 대하여 TDL 필터의 계수를 구할 수 있는 등가의 Wiener-Hopf 방정식을 제안한다. 본 논문에서 제안한 등가의 Wiener-Hopf 방정식을 이용하면 직교 입력 신호에 대하여 역 직교화 과정을 거치지 않고 직접적으로 TDL 필터의 계수와 오차를 표현할 수 있다. 본 논문에는 MMSE(minimum mean square error)에 대한 이론적 해석을 포함하였으며 수학적 예제에서 Wiener-Hopf 해와 제안한 등가의 Wiener-Hopf 해를 동시에 나타내었다.

생체자극으로써의 PRTS 신호의 이용에 관한 연구 (Using Pseudo-Random Ternary Sequence as Physiological Stimulus)

  • 탁계래
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.91-94
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    • 1997
  • In this paper, pseudo-random ternary sequence (PRTS) was used to investigate the cardiovascular and respiratory responses to hypoxia and hypercapnia. The actual input or this study was the changes in inhaled oxygen and carbon dioxide concentrations. It is hard to randomly change the concentration within a given breath. Since PRTS has almost the same statistical properties as Gaussian white noise, plus it is physically realizable, PRTS is used for this study. Using PRTS and Volterra kernels by Gram-Schmidt orthogonalization procedure, the cardiovascular and respiratory responses to hypoxia and hypercapnia were analyzed.

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Signal subspace comparison between Physical & synthesized array data in echo imaging

  • Choi, Jeong-Hee
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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    • pp.262-267
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    • 1998
  • In Synthetic Aperture Radar(SAR) imaging, the echoed data are collected by moving radar's position with respect to the target area, and this operation actually gives effect of synthesizing aperture size, which in turn gives better cross range resolution of reconstructed target scene. Among several inversion scheme for SAR Imaging, we uses an inversion scheme which uses no approximation in wave propagation analysis, and try to verify whether the collected data with synthesized aperture actually gives the same support as that with physical aperture in the same size. To do this, we make a signal subspace comparison of two imaging models with physical and synthesized arrays, respectively. Theoretical comparison and numerical analysis using Gram-Schmidt procedures had been performed. The results showed that the synthesized array data fully span the physical array data with the same system geometry and strongly support the proposed inversion scheme valuable in high resolution radar imaging.

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카오스 특성을 갖는 뇌파신호의 예측을 위한 신경회로망 설계에 관한 연구 (A Study on Design of Neural Network for the Prediction of EEG with Chaotic Characteristics)

  • 신창용;김택수;박상희
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1995년도 춘계학술대회
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    • pp.265-269
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    • 1995
  • In this study, we present a training method of radial basis function networks based on recursive modified Gram-Schmidt algorithm for single step prediction of chaotic time series. With single step predictions of Mackey-Glass time series and alpha-rhythm EEG which has chaotic characteristics, the radial basis function network trained by this method is compared with one trained by a classical non-recursive method and the radial basis function model proposed by X.D. He and A. Lapedes. The results show the effectiveness of the training method.

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초정밀 구조해석을 위한 수치절차의 영향 분석 (Investigation of the Effects of Some Numerical Procedure on the High Precision Structural Analysis)

  • 정강식;유홍희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.756-761
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    • 2004
  • The effects of two important numerical procedures on the high precision structural analysis are investigated in this study. The two numerical procedures include continuous variable approximation and time integration. For the continuous variable approximation, polynomial mode functions generated by the Gram-Schmidt process are introduced and the numerical results obtained by employing the polynomial mode functions are compared to those obtained by classical beam mode functions. The effect of the time integration procedure on the analysis precision is also investigated. It is found that the two procedures affect the precision of structural analysis significantly.

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Codebook-Based Precoding for SDMA-OFDMA with Spectrum Sharing

  • Jo, Han-Shin
    • ETRI Journal
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    • 제33권6호
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    • pp.831-840
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    • 2011
  • This paper focuses on codebook-based precoding for space-division multiple access/orthogonal frequency-division multiple access (SDMA-OFDMA) systems aiming to guarantee high throughput for their users as well as to mitigate interference to fixed satellite service (FSS). A systematic design of SDMA codebook for subband-based OFDMA is proposed, which forms multiple orthogonal beams with common spatial null in the direction of a victim FSS earth station (ES). The design enables both transmitter and receiver to independently construct identical codebook by sharing only on the direction angle of an FSS ES, which takes fewer overhead bits than Gram-Schmidt process, a general method satisfying our design criterion. A system-level throughput evaluation shows that the proposed precoding provides superior performance over existing spectrum sharing method, that is, subband deactivation. The spectrum sharing analysis shows that the proposed precoding, even with an estimation error of the direction angles of an FSS ES, causes lower interference than existing precoding, knockdown precoding.