The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Tianzi Jiang - One of the best experts on this subject based on the ideXlab platform.
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A modified temporal self-Correlation Method for analysis of fMRI time series.
Neuroinformatics, 2003Co-Authors: Yufeng Zang, Tianzi JiangAbstract:Temporal self-Correlation has recentlybeen proposed as a measure for fMRI-activation detection. In this paper, a modified temporal self-Correlation Method is introduced. The modified temporal self-Correlation is based on the expectation value and standard deviation of the Correlation coefficients between all pairs of epochs, while the original temporal self-Correlation Method is only based on the expectation value. Performance of the proposed Method is evaluated on both simulated and in vivo fMRI data. Compared with the original temporal self-Correlation Method, the proposed Method shows a significant improvement. In addition, a technique for quantitative comparison of different fMRI data analysis Methods is proposed.
L. Shen - One of the best experts on this subject based on the ideXlab platform.
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Study on laser speckle Correlation Method applied in triangulation displacement measurement
Journal of Optical Technology, 2013Co-Authors: L. Shen, D. G. LiAbstract:Laser speckle is a kind of noise in triangulation displacement measurement. It’s meaningless to restrain speckles when the imaging light spot is so weak that facular image cannot be extracted from speckles. Speckles can also be viewed as a kind of information carrier of displacement of the interface. In this paper, digital Correlation Method was used in laser triangulation displacement measurement system to measure the displacement of rough surface with strong scattering and the experimental results were analyzed. The results show that the digital Correlation Method is feasible in triangulation displacement measurement system, the measuring range can reach micron grade and the experimental errors are below 2%. This Method can overcome the disadvantage of traditional laser triangular displacement measurement in rough surface with strong scattering, improve the accuracy and expand the scope of application.
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A study on laser speckle Correlation Method applied in triangulation displacement measurement
Optik, 2013Co-Authors: L. Shen, Dinggen LiAbstract:Abstract The laser speckle is a kind of noise in triangulation displacement measurement. It is meaningless to restrain speckles when the light spot is so weak that facular image cannot be extracted from speckles. Speckles are also a kind of carrier of displacement information. Digital Correlation Method was used in laser triangulation displacement measurement system to measure the displacement of rough surface with strong scattering and analyze the results. The results showed that the digital Correlation Method is feasible in triangulation displacement measurement system, the measuring range reached micron grade and the experimental errors are below 2%. This Method can overcome the disadvantage of laser triangular displacement measurement system in rough surface with strong scattering, improve the accuracy and expand its range of application.
N. Ravot - One of the best experts on this subject based on the ideXlab platform.
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Self-adaptive Correlation Method for soft defect detection in cable by reflectometry
2014Co-Authors: S. Sallem, N. RavotAbstract:The self-adaptive Correlation Method (SACM), based on a temporal processing, consists in treating the reflectogram in order to amplify the signatures of soft defects and make them more easily detectable. The algorithm amplifies any signature correlated with the injection pulse. Amplification is more important as the amplitude of the soft defect is low, and reciprocally. Thus, this Method allows to highlight the soft defect while attenuating the noise present on the reflectogram. The term "self-adaptive" means that the gain is automatically adjusted depending on the amplitude of the soft defect signature. This Method is applicable to different reflectometry techniques with different waveforms and different position of the defect in the cable. This innovative approach has the advantage of reducing the computational complexity compared to the state of the art.
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Joint self-adaptive Correlation Method and modified empirical mode decomposition for soft defect detection in cable by reflectometry
Progress in Electromagnetics Research Letters, 2014Co-Authors: S. Sallem, N. RavotAbstract:In a previous paper, we have introduced an innovative approach called the self-adaptive Correlation Method (SACM). It consists in treating the reflectogram in order to amplify the signatures of soft defects and make them more easily detectable. This Method allows to highlight the soft defect while attenuating the noise present on the reflectogram and has the advantage of reducing the computational complexity compared to the state of the art. We drew attention to the sensitivity of the performance of this Method to noise. In this paper, we propose a solution for the pre-denoising of reflectogram before applying the SACM. This solution consists of an adapted version of the empirical mode decomposition algorithm, we called MEMD for Modified Empirical Mode Decomposition which bypasses some limitations of the conventional EMD.
Remi Michel - One of the best experts on this subject based on the ideXlab platform.
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flow of glaciar moreno argentina from repeat pass shuttle imaging radar images comparison of the phase Correlation Method with radar interferometry
Journal of Glaciology, 1999Co-Authors: Remi MichelAbstract:High-resolution radar images of Glaciar Moreno, Argentina, acquired by the Shuttle Imaging Radar C (SIR-C) on 9 and 10 October 1994 at 24 cm wavelength (L-band), are utilized to map the glacier velocity both interferometrically and using the phase Correlation Method. The precision of the interferometric ice velocities is 1.8 cm d-1 (6 m a-1) (1σ). The phase Correlation Method measures ice velocity with a precision of 14 cm d-1 (50 m a-1) with image data at a 6 m sample spacing acquired 1 day apart. Averaged strain rates are measured with a precision of 10-4 d-1 at a 240 m sample spacing with the phase Correlation Method, and 10-5 d-1 with radar interferometry. The phase Correlation Method is less precise than radar interferometry, but it performs better in areas of rapid flow, is more robust to temporal changes in glacier scattering and measures the glacier velocity in two dimensions with only one image pair. Using this technique, we find that Glaciar Moreno flows at 400 m a-1 in the terminal valley and 800 m a-1 at the calving front, in agreement with velocities recorded a decade ago. Assuming steady-state flow conditions, the vertical strain rates measured by SIR-C are combined with prior data on mass ablation to estimate the glacier thickness and ice discharge. The calculated discharge is 0.6 ± 0.2 km3 ice a-1 at 300 m elevation, and 1.1 ± 0.2 km3 ice a-1 at the equilibrium-line elevation (1150 m), which yields a balance accumulation of 6 ± 1m ice a-1.
Yufeng Zang - One of the best experts on this subject based on the ideXlab platform.
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A modified temporal self-Correlation Method for analysis of fMRI time series.
Neuroinformatics, 2003Co-Authors: Yufeng Zang, Tianzi JiangAbstract:Temporal self-Correlation has recentlybeen proposed as a measure for fMRI-activation detection. In this paper, a modified temporal self-Correlation Method is introduced. The modified temporal self-Correlation is based on the expectation value and standard deviation of the Correlation coefficients between all pairs of epochs, while the original temporal self-Correlation Method is only based on the expectation value. Performance of the proposed Method is evaluated on both simulated and in vivo fMRI data. Compared with the original temporal self-Correlation Method, the proposed Method shows a significant improvement. In addition, a technique for quantitative comparison of different fMRI data analysis Methods is proposed.
