• 제목/요약/키워드: Correlation estimation

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Zero-Crossing-Based Source Direction Estimation Using a Cepstral Prefiltering Technique (영교차점과 켑스트럼 전처리 기술을 이용한 반향환경에서의 음원방향 추정)

  • Park, Yong-Jin;Lee, Soo-Yeon;Park, Hyung-Min
    • MALSORI
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    • no.67
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    • pp.121-133
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    • 2008
  • To estimate directions of multi-sound sources, we consider an approach based on zero crossings which provided more robust results to diffuse noise than the conventional cross-correlation-based method [6][7]. In reverberant environments, the performance of source direction estimation can be improved by using signal components through direct paths from sources to microphones. Since a cepstral prefiltering technique [8] removes the effect of reverberation, we propose a source direction estimation method which can find out intervals of the direct-path components by comparing original and cepstral-prefiltered envelopes. Simulations demonstrate that the proposed method can improve the performance of source direction estimation in reverberant environments.

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Hierarchical Age Estimation based on Dynamic Grouping and OHRank

  • Zhang, Li;Wang, Xianmei;Liang, Yuyu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.7
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    • pp.2480-2495
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    • 2014
  • This paper describes a hierarchical method for image-based age estimation that combines age group classification and age value estimation. The proposed method uses a coarse-to-fine strategy with different appearance features to describe facial shape and texture. Considering the damage to continuity between neighboring groups caused by fixed divisions during age group classification, a dynamic grouping technique is employed to allow non-fixed groups. Based on the given group, an ordinal hyperplane ranking (OHRank) model is employed to transform age estimation into a series of binary enquiry problems that can take advantage of the intrinsic correlation and ordinal information of age. A set of experiments on FG-NET are presented and the results demonstrate the validity of our solution.

Influences of Energy Production Estimation Errors on Project Feasibility Indicators of a Wind Project and Critical Factor Analysis by AHP (풍력발전사업 에너지생산량 산정 오차가 사업성지표에 미치는 영향 및 AHP를 이용한 중요인자 분석)

  • Kim, Youngkyung;Chang, Byungman
    • Korean Management Science Review
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    • v.30 no.2
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    • pp.1-10
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    • 2013
  • Case studies are made to investigate the relationship between the accuracy of energy production estimation and project feasibility indicators such as rate of return on equity (ROE) and debt service coverage ratio (DSCR) for three wind farm projects. It is found out that 1% improvement in the accuracy of energy production estimation may enhance the ROE by more than 0.5% in the case of P95, thanks to improved financing terms. AHP survey shows that MCP correlation of measured in situ wind data with long term wind speed distribution and hands-on experiences of flow analysis are more important than other factors for more precise annual energy production estimation.

Subpixel Shift Estimation in Noisy Image Using Iterative Phase Correlation of A Selected Local Region (잡음 영상에서 국부 영역의 반복적인 위상 상관도를 이용한 부화소 이동량 추정방법)

  • Ha, Ho-Gun;Jang, In-Su;Ko, Kyung-Woo;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.1
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    • pp.103-119
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    • 2010
  • In this paper, we propose a subpixel shift estimation method using phase correlation with a local region for the registration of noisy images. Phase correlation is commonly used to estimate the subpixel shift between images, which is derived from analyzing shifted and downsampled images. However, when the images are affected by additive white Gaussian noise and aliasing artifacts, the estimation error is increased. Thus, instead of using the whole image, the proposed method uses a specific local region that is less affect by noises. In addition, to improve the estimation accuracy, iterative phase correlation is applied between selected local regions rather than using a fitting function. the restricted range is determined by analyzing the maximum peak and the two adjacent values of the inverse Fourier transform of the normalized cross power spectrum. In the experiments, the proposed method shows higher accuracy in registering noisy images than the other methods. Thus, the edge-sharpness and clearness in the super-resolved image is also improved.

An Adaptive Time Delay Estimation Method Based on Canonical Correlation Analysis (정준형 상관 분석을 이용한 적응 시간 지연 추정에 관한 연구)

  • Lim, Jun-Seok;Hong, Wooyoung
    • The Journal of the Acoustical Society of Korea
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    • v.32 no.6
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    • pp.548-555
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    • 2013
  • The localization of sources has a numerous number of applications. To estimate the position of sources, the relative delay between two or more received signals for the direct signal must be determined. Although the generalized cross-correlation method is the most popular technique, an approach based on eigenvalue decomposition (EVD) is also popular one, which utilizes an eigenvector of the minimum eigenvalue. The performance of the eigenvalue decomposition (EVD) based method degrades in the low SNR and the correlated environments, because it is difficult to select a single eigenvector for the minimum eigenvalue. In this paper, we propose a new adaptive algorithm based on Canonical Correlation Analysis (CCA) in order to extend the operation range to the lower SNR and the correlation environments. The proposed algorithm uses the eigenvector corresponding to the maximum eigenvalue in the generalized eigenvalue decomposition (GEVD). The estimated eigenvector contains all the information that we need for time delay estimation. We have performed simulations with uncorrelated and correlated noise for several SNRs, showing that the CCA based algorithm can estimate the time delays more accurately than the adaptive EVD algorithm.

Fault detection of logic circuit by use of M-sequence correlation method

  • Miyata, Chikara;Kashiwagi, Hiroshi
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.24-29
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    • 1993
  • In this paper, the estimation of the structure of a logic circuit under test is made from the observation of the input-output correlation function by use of M-sequence, from which we can estimate whether or not any fault exist in the logic circuit. Especially, investigation was made in case of the 2_stage logic circuit. We checked theoretically the sequence of correlation function, and we have shown that the correlation function is a function of period of M-sequence only, land the appearing number of correlation function in a period is a constant value depending on the logic circuit only. And by computer simulations we have shown that the structure of the circuit under test can be estimated from the observation of sequence of correlation function.

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Correlation between Density and Magnetic Field in Compressible MHD Turbulence

  • Yoon, Hee-Sun;Cho, Jung-Yeon
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.86.1-86.1
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    • 2011
  • Most astrophysical systems are turbulent and magnetized. Magnetic field plays an important role in the dynamics of ISM and influence all of properties of astrophysical system. Information of magnetic field is very important to understand properties of astrophysical systems. For example, one way to obtain information of magnetic field is to use Rotation Measure. Mean strength of the magnetic field along the line of sight can be estimated from RM/DM. (where RM is rotation measure, DM is dispersion measure) For the estimation of magnetic field strength using RM/DM, the correlation between density and magnetic field is very important. When there is no correlation between density and magnetic field the relation gives exact mean magnetic field strength. But, if the correlation is positive, it overestimates the magnetic field strength, while if the correlation is negative, it underestimate the strength. We calculate correlation between density and magnetic field in compressible MHD turbulence.

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Estimation of high-dimensional sparse cross correlation matrix

  • Yin, Cao;Kwangok, Seo;Soohyun, Ahn;Johan, Lim
    • Communications for Statistical Applications and Methods
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    • v.29 no.6
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    • pp.655-664
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    • 2022
  • On the motivation by an integrative study of multi-omics data, we are interested in estimating the structure of the sparse cross correlation matrix of two high-dimensional random vectors. We rewrite the problem as a multiple testing problem and propose a new method to estimate the sparse structure of the cross correlation matrix. To do so, we test the correlation coefficients simultaneously and threshold the correlation coefficients by controlling FRD at a predetermined level α. Further, we apply the proposed method and an alternative adaptive thresholding procedure by Cai and Liu (2016) to the integrative analysis of the protein expression data (X) and the mRNA expression data (Y) in TCGA breast cancer cohort. By varying the FDR level α, we show that the new procedure is consistently more efficient in estimating the sparse structure of cross correlation matrix than the alternative one.

A Study on Correlation Interference Signal Cancellation Algorithm for Target Estimation in Multi Input Multi Output (다중 입력 다중 출력 배열 시스템에서 목표물 추정을 위한 상관성 간섭신호 제거 알고리즘 연구)

  • Lee, Kwan-Hyeong;Song, Woo-Young;Lee, Myeong-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.1
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    • pp.89-93
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    • 2013
  • This paper is estimating a target direction of arrival with incident to receiver in spatial. This paper presented covariance using constraint matrix to correlation interference signal cancellation in multi input multi output array antennas system. we proposed a target direction of arrival estimation algorithm using cost function and minimum variance method. Through simulation, we were analysis a performance to compare general SPT-LCMV algorithm and proposal algorithm. We showed that proposal algorithm improve more target estimation than general SPT-LCMV algorithm in direction of arrival.

A Study of Estimation for Web Software Size (웹 소프트웨어 규모 예측에 관한 연구)

  • KIM JeeHyun;YOO HaeYoung
    • The KIPS Transactions:PartD
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    • v.12D no.3 s.99
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    • pp.409-416
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    • 2005
  • Even though development paradigm of software has been changing very fast at the beginning of 21st Centuries, there are just few studies of quality and estimation metrics appropriate for Web environment. So in this study after analyzing the correlation between the size of the final code and property of objects, three industrial real world projects written in ASP have been used for deriving programs with high possibilities of faults. And then the size of programs was analyzed to correlate with the number of classes or the number of methods through linear regression. Among the web software with the complex architecture or server, client and un, type or form file written in Javascript for client has the high correlation and the number of methods is well correlated with the size of final code.