• Title/Summary/Keyword: Filter convergence

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Information Potential with Shifted Symbol Points and Related Blind Equalizer Algorithms (심볼점 평행이동 기능을 지닌 정보 포텐셜과 블라인드 등화 알고리듬)

  • Kim, Namyong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.2
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    • pp.3-10
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    • 2013
  • Please In this paper, to cope with biased impulsive noise problems, a new information potential is proposed that can move the transmitted symbol points by modifying the information potential designed with Dirac-delta functions. Based on the proposed information potential a new blind algorithm is derived by employing an augmented filter structure. From the simulation results in the environment of biased impulsive noise, the conventional algorithms yield performance degradation by over 15 dB, but the proposed algorithm shows no performance degradation and holds the same steady state MSE of below -25 dB as after the initial convergence regardless of the channel conditions.

Moving Object Trajectory based on Kohenen Network for Efficient Navigation of Mobile Robot

  • Jin, Tae-Seok
    • Journal of information and communication convergence engineering
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    • v.7 no.2
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    • pp.119-124
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    • 2009
  • In this paper, we propose a novel approach to estimating the real-time moving trajectory of an object is proposed in this paper. The object's position is obtained from the image data of a CCD camera, while a state estimator predicts the linear and angular velocities of the moving object. To overcome the uncertainties and noises residing in the input data, a Extended Kalman Filter(EKF) and neural networks are utilized cooperatively. Since the EKF needs to approximate a nonlinear system into a linear model in order to estimate the states, there still exist errors as well as uncertainties. To resolve this problem, in this approach the Kohonen networks, which have a high adaptability to the memory of the input-output relationship, are utilized for the nonlinear region. In addition to this, the Kohonen network, as a sort of neural network, can effectively adapt to the dynamic variations and become robust against noises. This approach is derived from the observation that the Kohonen network is a type of self-organized map and is spatially oriented, which makes it suitable for determining the trajectories of moving objects. The superiority of the proposed algorithm compared with the EKF is demonstrated through real experiments.

Information Potential and Blind Algorithms Using a Biased Distribution of Random-Order Symbols (랜덤 심볼열의 바이어스된 분포를 이용한 정보 포텐셜과 블라인드 알고리즘)

  • Kim, Namyong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.1
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    • pp.26-32
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    • 2013
  • Blind algorithms based on Information potential of output samples and a set of symbols generated in random order at the receiver go through performance degradation when biased impulsive noise is added to the channel since the cost function composed of information potentials has no variable to deal with biased signal. Aiming at the robustness against biased impulsive noise, we propose, in this paper, a modified information potential, and derived related blind algorithms based on augmented filter structures and a set of random-order symbols. From the simulation results of blind equalization for multipath channels, the blind algorithm based on the proposed information potential produced superior convergence performance in the environments of strong biased impulsive noise.

Nonlinear Adaptive Prediction using Locally and Globally Recurrent Neural Networks (지역 및 광역 리커런트 신경망을 이용한 비선형 적응예측)

  • 최한고
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.1
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    • pp.139-147
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    • 2003
  • Dynamic neural networks have been applied to diverse fields requiring temporal signal processing such as signal prediction. This paper proposes the hybrid network, composed of locally(LRNN) and globally recurrent neural networks(GRNN), to improve dynamics of multilayered recurrent networks(RNN) and then describes nonlinear adaptive prediction using the proposed network as an adaptive filter. The hybrid network consists of IIR-MLP and Elman RNN as LRNN and GRNN, respectively. The proposed network is evaluated in nonlinear signal prediction and compared with Elman RNN and IIR-MLP networks for the relative comparison of prediction performance. Experimental results show that the hybrid network performs better with respect to convergence speed and accuracy, indicating that the proposed network can be a more effective prediction model than conventional multilayered recurrent networks in nonlinear prediction for nonstationary signals.

An Acoustic Noise Cancellation Using Subband Block Conjugate Gradient Algorithm (부밴드 블록 공액 경사 알고리듬을 이용한 음향잡음 제거)

  • 김대성;배현덕
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.3
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    • pp.8-14
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    • 2001
  • In this paper, we present a new cost function for subband block adaptive algorithm and block conjugate gradient algorithm for noise cancellation of acoustic signal. For the cost function, we process the subband signals with data blocks for each subbands and recombine it a whole data block. After these process, the cost function has a quadratic form in adaptive filter coefficients, it guarantees the convergence of the suggested block conjugate gradient algorithm. And the block conjugate gradient algorithm which minimizes the suggested cost function has better performance than the case of full-band block conjugate gradient algorithm, the computer simulation results of noise cancellation show the efficiency of the suggested algorithm.

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Blind Algorithms using a Random-Symbol Set under Biased Impulsive Noise (바이어스 된 충격성 잡음 하에서 랜덤 심볼 열을 이용한 블라인드 알고리듬)

  • Kim, Namyong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.4
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    • pp.1951-1956
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    • 2013
  • Distribution-matching type algorithms based on a set of symbols generated in random order provide a limited performance under biased impulsive noise since the performance criterion for the algorithms has no variables for biased signal. For the immunity against biased impulsive noise, we propose, in this paper, a modified performance criterion and derived related blind algorithms based on augmented filter structures and the distribution-matching method using a set of random symbols. From the simulation results, the proposed algorithm based on the proposed criterion yielded superior convergence performance undisturbed by the strong biased impulsive noise.

X-ray fluorescence spectrum of the block algorithm to apply the interval threshold method using DWT (DWT를 이용한 형광 X-선 스펙트럼의 interval Threshold를 적용하기 위한 블록화 알고리즘)

  • Yang, Sang-Hoon;Lee, Jae-Hwan;Park, Dong-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.5
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    • pp.2291-2297
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    • 2012
  • X-ray fluorescence sprectrum signal include the continuum. XRF analysis the components of material by the amplitude of peaks. XRF remove the noise and background. To remove the noise, we apply the smoothing filter. And background removal methods applied such as SNIP, Morphology, Threshold methods. In this paper, we applied Threshold using DWT. Interval threshold method divide the some blocks in particular levels. We propose the method that is divided the particular level.

A Study on the Design of Cross-Polarization Interference Canceler for Digital Radio Relay System with Co-Channel Dual Polarization (동일 채널 이중편파를 적용하는 디지털 무선 중계장치의 직교편파간섭제거기 설계에 관한 연구)

  • 서경환
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.3
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    • pp.225-236
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    • 2002
  • In this paper, to counteract a cross-polarization interference caused by co-channel dual polarization technique of digital radio relay system(DRRS), we analyze the theoretical model and digital design of cross-polarization interference canceller(XPIC). In addition a complex adaptive time domain equalizer(ATDE) is designed using a finite impulse response filter, and the structure of XPIC and its control method are also illustrated including ATDE. Our computer simulation shows that about 25 dB signature and more than 23 dB XPIC improvement factor can be obtained with XPIC and ATDE. In order to verify the operation of designed XPIC, we review the simulated results in view of tap number, algorithm convergence, system signature, and XPlC improvement factor in connection with 64-QAM DRRS with co-channel dual polarization.

System Identification and Damage Estimation via Substructural Approach

  • Tee, K.-F.;Koh, C.-G.;Quek, S.-T.
    • Computational Structural Engineering : An International Journal
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    • v.3 no.1
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    • pp.1-7
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    • 2003
  • For system identification of large structures, it is not practical to identify the entire structure due to the prohibitive computational time and difficulty in numerical convergence. This paper explores the possibility of performing system identification at substructure level, taking advantage of reduction in both the number of unknowns and the number of degrees of freedom involved. Another advantage is that different portions (substructures) of a structural system can be identified independently and even concurrently with parallel computing. Two substructural identification methods are formulated on the basis whether substructural approach is used to obtain first-order or second-order model. For substructural first-order model, identification at the substructure level will be performed by means of the Observer/Kalman filter Identification (OKID) and the Eigensystem Realization Algorithm (ERA) whereas identification at the global level will be performed to obtain second-order model in order to evaluate the system's stiffness and mass parameters. In the case of substructural second-order model, identification will be performed at the substructure level throughout the identification process. The efficiency of the proposed technique is shown by numerical examples for multi-storey shear buildings subjected to random forces, taking into consideration the effects of noisy measurement data. The results indicate that both the proposed methods are effective and efficient for damage identification of large structures.

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Performance Characteristics of Subband Adaptive Array Antenna using Kalman Algorithm (Kalman 알고리즘에 의한 대역분할. 합성형 어댑티브 어레이 안테나의 동작 특성)

  • 박재성;오경석;주창복;박남천;정주수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.3
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    • pp.501-507
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    • 1999
  • At the mobile unit for adaptation the propagation environment, it is necessity to adapt very fast the weight coefficient vector of adaptive array antenna In this paper, for the BPSK and BFSK signals with S/I=2, S/N=10 subband adaptive array signal processing method to the linear array antenna using the LMS & the Kalman filter algorithm is proposed. For the 4 elements equidistance linear array antenna systems LMS and Kalman algorithms with subband adaptive instruction principles using the subband signal processing method are adopted and the computer simulation results to the constant amplitude envelope signals such as BPSK or BFSK can be seen that the convergence characteristics of directional patterns and the signal following characteristics are more fast and stable.

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