• 제목/요약/키워드: correlation algorithm

검색결과 1,940건 처리시간 0.031초

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

  • Qin, Hao;Song, Bin;Zhao, Yue;Liu, Haihua
    • ETRI Journal
    • /
    • 제34권2호
    • /
    • pp.190-198
    • /
    • 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
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
    • /
    • pp.208-211
    • /
    • 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.

  • PDF

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

  • Han, Yong-Sik;Yang, Woon-Geun
    • Journal of information and communication convergence engineering
    • /
    • 제8권2호
    • /
    • pp.155-158
    • /
    • 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.

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

  • 이우찬;서동철;김용철
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
    • /
    • pp.2113-2115
    • /
    • 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.

  • PDF

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

  • Lee, Ae-Kyoung
    • ETRI Journal
    • /
    • 제17권3호
    • /
    • pp.45-63
    • /
    • 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.

  • PDF

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

  • 유창호;고남곤;최재원;서영봉
    • 제어로봇시스템학회논문지
    • /
    • 제16권7호
    • /
    • pp.703-710
    • /
    • 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.

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

  • 권순용;오신범;이채욱
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2000년도 추계종합학술대회 논문집(4)
    • /
    • pp.115-118
    • /
    • 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.

  • PDF

A Study on Multi-Signal DOA Estimation in Fading Channels

  • Lee Kwan-Houng;Song Woo-Young
    • Journal of information and communication convergence engineering
    • /
    • 제3권3호
    • /
    • pp.115-118
    • /
    • 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
    • /
    • 제1권2호
    • /
    • pp.192-199
    • /
    • 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.

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

  • 정준우;김경환
    • 한국멀티미디어학회논문지
    • /
    • 제13권4호
    • /
    • pp.535-546
    • /
    • 2010
  • 디지털 영상은 조명 조건과 취득 카메라의 고유 특성으로 인해 의도하지 않은 색조를 가질 수 있다. 영상에 색조가 존재하면 일관된 색 정보의 인지 및 표현이 어렵기 때문에 별도의 색 보정 작업이 필요하다. 본 논문은 color by correlation을 사용한 학습 영상 선택, 후보 회색축 영역의 추출, 핵밀도 추정, 색조 제거의 4단계로 이루어진 색조 추출 및 제거 방법을 제안한다. 후보 회색축 영역 중 불명확한 회색축 영역을 핵밀도 추정을 이용하여 제거하였다. 후보 회색축 영역의 색 성분의 분포를 조사하여 색조 유무를 판단하고, 색조가 존재할 경우 색조 제거 작업을 통하여 색 항상성을 유지 시켰다. 실험을 통해 제안하는 방법이 gray world 방법, color by correlation 방법 보다 정확한 색조 추정이 가능함을 확인하였다.