An approach for long-range passive impulsive source ranging with a single receiver in shallow water is proposed, which utilizes the frequency spectrum of the warped signal autocor- relation function via warping transf...An approach for long-range passive impulsive source ranging with a single receiver in shallow water is proposed, which utilizes the frequency spectrum of the warped signal autocor- relation function via warping transform. For an ideal waveguide, there are invariable frequency features both in the frequency spectrum of the warped signal corresponding to modal cut-off frequencies and the warped signal autocorrelation function due to modal interference. These intrinsic frequency features can be used to passive source ranging. So, the approximate rela- tionship between the frequency of warped signal at an unknown source range and the intrinsic frequency extracted by the time warping transform is derived. These rules can be generalized to an actual shallow water waveguide. Employing an acoustic model to offer the invariable frequency spectrum features, the impulsive signal data collected by a single hydrophone in the North Yellow Sea in December 2011 are analyzed to verify the proposed source ranging ap- proach. The estimated ranges are in good agreement with the ranges measured by GPS, and the mean relative error of range estimation is less than 10%.展开更多
A novel method based on the extended infomax approach of independent component analysis (ICA) is proposed for the single trial estimation of multi channel pattern reversal visual evoked potential (PVEP). The clin...A novel method based on the extended infomax approach of independent component analysis (ICA) is proposed for the single trial estimation of multi channel pattern reversal visual evoked potential (PVEP). The clinical applications illustrate the encouraging performance of the method. The number of trials needed is reduced to 3, but the estimated VEP complex is clearer than that obtained by conventional ensemble averaging with 50 trials. By analyzing the time course and spatial pattern of the independent components (ICs) of the multi channel PVEP, one component is found to be reasonably related to the P100 peak.展开更多
基金supported by the Program of One Hundred Talented People of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(11174312,10974218,11125420)
文摘An approach for long-range passive impulsive source ranging with a single receiver in shallow water is proposed, which utilizes the frequency spectrum of the warped signal autocor- relation function via warping transform. For an ideal waveguide, there are invariable frequency features both in the frequency spectrum of the warped signal corresponding to modal cut-off frequencies and the warped signal autocorrelation function due to modal interference. These intrinsic frequency features can be used to passive source ranging. So, the approximate rela- tionship between the frequency of warped signal at an unknown source range and the intrinsic frequency extracted by the time warping transform is derived. These rules can be generalized to an actual shallow water waveguide. Employing an acoustic model to offer the invariable frequency spectrum features, the impulsive signal data collected by a single hydrophone in the North Yellow Sea in December 2011 are analyzed to verify the proposed source ranging ap- proach. The estimated ranges are in good agreement with the ranges measured by GPS, and the mean relative error of range estimation is less than 10%.
基金Supported by the National Natural Science Foundation of China( No.5 993 7160 )
文摘A novel method based on the extended infomax approach of independent component analysis (ICA) is proposed for the single trial estimation of multi channel pattern reversal visual evoked potential (PVEP). The clinical applications illustrate the encouraging performance of the method. The number of trials needed is reduced to 3, but the estimated VEP complex is clearer than that obtained by conventional ensemble averaging with 50 trials. By analyzing the time course and spatial pattern of the independent components (ICs) of the multi channel PVEP, one component is found to be reasonably related to the P100 peak.
