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A new algorithm for speech enhancement based on wavelet shrinkage method is presented in this paper. First, the noisy speech by the Bark-scaled Wavelet Packet (BS-WPD) is decomposed to simulate the human auditory characteristics. Then a new thresholding algorithm which has many advantages over soft and hard thresholdings put forward by D.L. Donoho and I.M. Johnstone is proposed. Simulation results indicate that this new method is very useful and efficient in the process of white noise reduction from speech, and the new thresholding algorithm gives better SNR improvement than other traditional thresholding algorithms.

Commom method have low sorting rates and is rensitive to the Signal Noise Radio (SNR), thus, resemblance coefficient of bispectrum two dimensions characteristic is applied to sort unknown complicated radar signal to obtain high sorting rate. The bispectrum of received signal is extracted, and it is predigested to two dimensions characteristic. A rectangle pulse sequence and triangle pulse sequence are constructed. Then, the resemblance coefficient of two dimensions characteristic with rectangle pulse sequence and triangle pulse sequence are gained, and they are used as the sorting parameters. The bispectrum of different signal is distinguishing and it is not sensitive to SNR and the resemblance coefficient is divisible and steady. The advantage of this new method is validated by simulation results and the sorting rate is not less than 86% at SNR of 5 dB.

We investigate the theoretical and observational implications of the acceleration of protons and heavier nuclei in supernova remnants (SNRs). By adopting a semi-analytical technique, we study the non-linear interplay among particle acceleration, magnetic field generation and shock dynamics, outlining a self-consistent scenario for the origin of the spectrum of Galactic cosmic rays as produced in this class of sources. Moreover, the inferred chemical abundances suggest nuclei heavier than Hydrogen to be relevant not only in the shock dynamics but also in the calculation of the γ-ray emission from SNRs due to the decay of neutral pions produced in nuclear interactions.