A method for efficient quantization of speech spectral models is proposed. The impulse response of the model is coded in two spectral subbands of unequal width. The distortion measure used is a squared error between impulse responses. The quality obtained at 22 bits per frame is as good as that of Split Vector Quantization of Line Spectral Frequencies at 24 bits per frame.

A fluorescence assay was used to measure the processivity of Escherichia coli recBCD enzyme helicase activity. Under standard conditions, recBCD enzyme unwinds an average of 30 +/- 3.2 kilobase pairs (kb)/DNA end before dissociating. The average processivity (P obs) of DNA unwinding under these conditions is 0.99997, indicating that the probability of unwinding another base pair is 30,000-fold ...

as an application of hirota bilinear method, perturbation expansion truncated at different levels is used to obtain exact soliton solutions to (2+1)-dimensional nonlinear evolution equation in much simpler way in comparison to other existing methods. we have derived bilinear form of nonlinear evolution equation and using this bilinear form, bilinear backlund transformations and construction of ...

Let (G;N) be a pair of groups. In this article, first we con-struct a relative central extension for the pair (G;N) such that specialtypes of covering pair of (G;N) are homomorphic image of it. Second, weshow that every perfect pair admits at least one covering pair. Finally,among extending some properties of perfect groups to perfect pairs, wecharacterize covering pairs of a perfect pair (G;N)...