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Simulation model of micro-grid including a direct-drive wind power generation, two sets of power-controlled distributed generations (DGs) and a three-phase fault module was investigated in Matlab/simulink. Based on the constructed model, the operating process switched from island mode to grid-connected mode was simulated and the voltage variance signal was detected with Daubechies(Db) wavelet. The...
Digital radiographs play very important role in medical imaging. However, the image quality has weakness with lower contrast and some noises owing to various reasons. So it is necessary to enhance these images to facilitate the postprocessing or diagnosis. In this paper, our method utilized wavelet transform to decompose the image, removed the noise using wavelet threshold method, and modified the...
Lifting wavelet is a useful method to analyze the abrupt signal because lifting wavelet can simultaneously show the local characteristic of time domain signal and frequency domain signal. The dynamic power quality disturbance in modern power supply can usually engender the fault signal such as voltage sag, voltage swell and voltage interruption. Lifting wavelet and Fourier transform are used respectively...
Data fusion is a very effective technique which can be applied to many remote sensing areas such as battle awareness, monitoring of environmental surveillance and man-made target detection. In this paper, we test fusion of multiple polarization (HH, HV , VH and W) SAR images, which is performed using multiscale image fusion technique based on combined curvelet and wavelet transform. Curvelet transform...
In this paper, the application of wavelet transform (WT) and wavelet packet transform (WPT) for ECG signals of atrial fibrillation (AF) is presented. Original ECG signals of AF are de-noised, reconstructed and decomposed by WT and WPT. Entropies of each node of the reconstructed ECG signal of AF are calculated. Based on the best basis method and the MDL (minimum description length) criterion, for...
In order to improve the error resilient ability and transmission efficiency for image transmission over wireless frequency selective fading channels, a joint source-channel coding (JSCC) scheme was proposed. In which, MIMO-OFDM and adaptive wavelet pretreatment were combined together. MIMO-OFDM was used to deal with frequency-selective, time dispersive characterize of wireless fading channels; adaptive...
In order to improve the error resilient ability and transmission efficiency for image transmission over wireless frequency selective fading channels, a joint source-channel coding ( JSCC) scheme was proposed. In which, MlMO-OFDM and adaptive wavelet pretreatment were combined together. MlMO-OFDM was used to deal with frequency-selective, time dispersive characterize of wireless fading channels; adaptive...
We used the method of wavelet packet transform to decompose the R-R intervals of normal sinus rhythm and atrial fibrillation ECG. We analyzed the generalized Hurst exponents for the decompose signals used the multifractal detrended fluctuation analysis (MF-DFA) method. The results show that the R-R intervals sequences have multi-fractal properties. The method of wavelet packet translation can reduce...
To detect the HIS-bundle signals from surface electrophysiological signal (ECG), we used the wavelet transformation to analyze the signals. Then we used stochastic resonance method to amplify the transformed signals. We used the method to analyze a rabbit's surface ECG while compared with its endocardiac signals. It could be seen that these analysis tools enhanced the weak signals effectively
This paper aims to analyze the dynamic characteristics of the postural sway measurements, the curves of the velocity and acceleration of the postural sway measurements were used. The curves of smoothed velocity and acceleration were got through the filter of Haar wavelet packet decomposing function. At the increasing of age, the velocity and acceleration of the postural sway measurements are increasing,...
We investigated elimination of electrocardiogram (ECG) artifacts from the myoelectric prosthesis control signals, taken from the reinnervated pectoralis muscles of a patient with bilateral amputations at shoulder disarticulation level. The performance of various ECG artifact removal methods including high pass filtering, spike clipping, template subtracting, wavelet thresholding and adaptive filtering...
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