• Title/Summary/Keyword: correlation algorithm

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Adaptive Correlation Noise Model for DC Coefficients in Wyner-Ziv Video Coding

  • Qin, Hao;Song, Bin;Zhao, Yue;Liu, Haihua
    • ETRI Journal
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    • v.34 no.2
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    • pp.190-198
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    • 2012
  • An adaptive correlation noise model (CNM) construction algorithm is proposed in this paper to increase the efficiency of parity bits for correcting errors of the side information in transform domain Wyner-Ziv (WZ) video coding. The proposed algorithm introduces two techniques to improve the accuracy of the CNM. First, it calculates the mean of direct current (DC) coefficients of the original WZ frame at the encoder and uses it to assist the decoder to calculate the CNM parameters. Second, by considering the statistical property of the transform domain correlation noise and the motion characteristic of the frame, the algorithm adaptively models the DC coefficients of the correlation noise with the Gaussian distribution for the low motion frames and the Laplacian distribution for the high motion frames, respectively. With these techniques, the proposed algorithm is able to make a more accurate approximation to the real distribution of the correlation noise at the expense of a very slight increment to the coding complexity. The simulation results show that the proposed algorithm can improve the average peak signal-to-noise ratio of the decoded WZ frames by 0.5 dB to 1.5 dB.

Fast landmark matching algorithm using moving guide-line image

  • Seo Seok-Bae;Kang Chi-Ho;Ahn Sang-Il;Choi Hae-Jin
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.208-211
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    • 2004
  • Landmark matching is one of an important algorithm for navigation of satellite images. This paper proposes a fast landmark matching algorithm using a MGLI (Moving Guide-Line Image). For searching the matched point between the landmark chip and a part of image, correlation matrix is used generally, but the full-sized correlation matrix has a drawback requiring plenty of time for matching point calculation. MGLI includes thick lines for fast calculation of correlation matrix. In the MGLI, width of the thick lines should be determined by satellite position changes and navigation error range. For the fast landmark matching, the MGLI provides guided line for a landmark chip we want to match, so that the proposed method should reduce candidate areas for correlation matrix calculation. This paper will show how much time is reduced in the proposed fast landmark matching algorithm compared to general ones.

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Adaptive Interference Cancellation Using CMA-Correlation Normalized LMS for WCDMA System

  • Han, Yong-Sik;Yang, Woon-Geun
    • Journal of information and communication convergence engineering
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    • v.8 no.2
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    • pp.155-158
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    • 2010
  • In this article, we proposed a new interference canceller using the adaptive algorithm. We designed constant modulus algorithm-correlation normailized least mean square (CMA-CNLMS) for wireless system. This structure is normalized LMS algorithm using correlation between the desired and input signal for cancelling the interference signals in the wideband code division multiple access (WCDMA) system. We showed that the proposed algorithm could improve the Mean Square Error (MSE) performance of LMS algorithm. MATLAB (Matrix Laboratory) is employed to analyze the proposed algorithm and to compare it with the experimental results. The MSE value of the LMS with mu=0.0001 was measured as - 12.5 dB, and that of the proposed algorithm was -19.5 dB which showed an improvement of 7dB.

Error Concealment Algorithm using Spatio-Temporal Correlation (Spatio-Temporal Correlation을 이용한 동영상 오류 은닉 알고리즘)

  • Lee, Woo-Chan;Seo, Dong-Cheul;Kim, Yong-Chul
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.2113-2115
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    • 2006
  • This paper proposes a spatio-temporal correlation algorithm that takes advantage of the spatial and temporal correlations in video streams for error concealment. The spatio-temporal correlation algorithm sets the neighborhood area of the damaged part as a reference window, then finds the area that best matches the reference window in the previous frame. The best-matched area in the previous frame replaces the damaged part in the current frame. The results of ten variations of the proposed algorithm are compared with conventional error concealment methods. These methods include the ones applicable to P-frames as well as I-frames. The comparison results show that the proposed algorithm is very efficient for l-frame error concealment with a large motion between frames.

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An Advanced Correlation Algorithm between GTEM and OATS for Radiated Emission Tests

  • Lee, Ae-Kyoung
    • ETRI Journal
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    • v.17 no.3
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    • pp.45-63
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    • 1995
  • This paper proposes an algorithm to improve the correlation between giga-hertz transverse electromagnetic (GTEM) cell and open area test site (OATS). It is based on the dipole modeling process of an unknown source object in a GTEM cell and on the evaluation of the approximate far field equations correlated with measured GTEM powers at output port of the GTEM cell. In this algorithm, the relative phase differences between dipole moments play an important part in modeling the test object as a set of dipoles and offer stable calculation of emission values. The radiated emission test using this algorithm requires fifteen orientations of equipment under test, but the increased orientations as compared with the previous method have little effect on the time needed for testing. Radiation from a notebook computer has been tested for statistical analysis of the correlation between GTEM data and OATS data. The emission test results of the notebook computer show that the mean, the standard deviation, and the correlation coefficient are -0.62, 1.99, and +0.85, respectively. These figures indicate that this algorithm provides improved accuracy in the measurement of electromagnetic emissions over the previous method.

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An Overload Detecting Method for an Excavator Based on the Correlation Function (상관함수 기반 굴삭기용 과부하 검출 기법)

  • Yu, Chang-Ho;Ko, Nam-Kon;Choi, Jae-Weon;Seo, Young-Bong
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.7
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    • pp.703-710
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    • 2010
  • In this paper, an overload detecting algorithm for an excavator is presented. The proposed overload detecting algorithm is based on the time series analysis especially correlation function. The main purpose of this paper is to prevent damage or crack from the fatigue loaded on an excavator in advance. Generally, the larger data, the longer processing time, and the amount of the data used in this paper are also large, especially every sampling period, 1600 data are gathered and calculated. So this paper focuses on minimizing the number of required sensors by using the correlation function. From the cross correlation function, similar pattern sensors are eliminated and dissimilar pattern sensors are considered, and from the auto correlation function, the overload can be detected. To prove the efficiency of the proposed overload detecting algorithm, this paper shows the computer simulation results.

A Study on Variable Step Size LMS Algorithm using estimated correlation (추정상관값을 이용한 가변 스텝사이즈 LMS 알고리듬에 관한 연구)

  • 권순용;오신범;이채욱
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.115-118
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    • 2000
  • We present a new variable step size LMS algorithm using the correlation between reference input and error signal of adaptive filter. The proposed algorithm updates each weight of filter by different step size at same sample time. We applied this algorithm to adaptive multip]e-notch filter. Simulation results are presented to compare the performance of the proposed algorithm with the usual LMS algorithm and another variable step algorithm.

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A Study on Multi-Signal DOA Estimation in Fading Channels

  • Lee Kwan-Houng;Song Woo-Young
    • Journal of information and communication convergence engineering
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    • v.3 no.3
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    • pp.115-118
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    • 2005
  • In this study, the proposed algorithm is a correlativity signal in a mobile wireless channel that has estimated the direction of arrival. The proposed algorithm applied the space average method in a MUSIC algorithm. The diagonal matrix of the space average method was changed to inverse the matrix and to obtain a new signal correlation matrix. The existing algorithm was analyzed and compared by applying a proposed signal correlation matrix to estimate the direction of arrival in a MUSIC algorithm. The experiment resulted in a proposed algorithm with a min-norm method resolution at more than $5^{\circ}$. It improved more than $2^{\circ}$ in a MUSIC algorithm.

An Improved Anti-Islanding Algorithm for Utility Interconnection of Multiple Distributed Fuel Cell Powered Generations

  • Jeraputra Chuttchaval;Hwang In-Ho;Choi Se-Wan;Aeloiza Eddy C.;Enjeti Prasad N.
    • Journal of Electrical Engineering and Technology
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    • v.1 no.2
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    • pp.192-199
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    • 2006
  • This paper presents an improved anti-islanding algorithm for utility interconnection of multiple distributed fuel cell powered generations (DFPGs). A cross-correlation method is proposed and implemented in conjunction with the anti-islanding algorithm developed in the previous work [I]. While the power control algorithm continuously perturbs $({\pm}5%)$ the reactive power supplied by the DFPG, the proposed algorithm calculates the cross-correlation index of a rate of change of the frequency deviation with respect to $({\pm}5%)$ the reactive power to confirm islanding. If this index is above 50%, the algorithm further initiates $({\pm}10%)$ the reactive power perturbation and continues to calculate the correlation index. If the index exceeds 80%, the occurrence of islanding can be confirmed. The proposed method is robust and capable of detecting the occurrence of islanding in the presence of several DFPGs, which are independently operating. Viability of the cross-correlation method is verified by the simulation. Experimental results are presented to support the findings of the proposed method.

Color cast detection based on color by correlation and color constancy algorithm using kernel density estimation (색 상관 관계 기반의 색조 검출 및 핵밀도 추정을 이용한 색 항상성 알고리즘)

  • Jung, Jun-Woo;Kim, Gyeong-Hwan
    • Journal of Korea Multimedia Society
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    • v.13 no.4
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    • pp.535-546
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    • 2010
  • Digital images have undesired color casts due to various illumination conditions and intrinsic characteristics of cameras. Since the color casts in the images deteriorate performance of color representations, color correction is required for further analysis of images. In this paper, an algorithm for detection and removal of color casts is presented. The proposed algorithm consists of four steps: retrieving similar image using color by correlation, extraction of near neutral color regions, kernel density estimation, and removal of color casts. Ambiguities in near neutral color regions are excluded based on kernel density estimation by the color by correlation algorithm. The method determines whether there are color casts by chromaticity distributions in near neutral color regions, and removes color casts for color constancy. Experimental results suggest that the proposed method outperforms the gray world algorithm and the color by correlation algorithm.