نتایج جستجو برای: windowed fast fourier transform

تعداد نتایج: 354175  

2013
S.China Venkateswarlu Rami Reddy K.Satya

This paper is aimed at to study LPC for Natural speech with different windowing techniques the effect of window shape on improving the speech quality by reducing the noise with the help of fixed and variable Windows with optimum shape. In the speech process signal corrupted by noise is segmented into frames and each segment is windowed using different Window with variation in the shape paramete...

2015
Applications Rutgers

Suppose we have a function s(t) that measures the sound level at time t of an analog audio signal. We assume that s(t) is piecewise-continuous and of finite duration: s(t) = 0 when t is outside some interval a ≤ t ≤ b. Make a change of variable x = (t− a)/(b− a) and set f(x) = s(t). Then 0 ≤ x ≤ 1 when a ≤ t ≤ b, and f(x) is a piecewise continuous function of x. We convert f(x) into a digital s...

2008
Jayakumar Ramanathan Pankaj Topiwala

The time-frequency content of a signal can be measured by the Gabor transform or windowed Fourier transform. This is a function defined on phase space that is computed by taking the Fourier transform of the product of the signal against a translate of a fixed window. The problem of finding signals with Gabor transform that are maximally concentrated within a given region of phase space is discu...

2008
Luis Caffarelli Matteo Bonforte Juan Luis Vazquez

We investigate qualitative properties of local solutions u(t, x) ≥ 0 to the fast diffusion equation, ∂tu = ∆(u )/m with m < 1, corresponding to general nonnegative initial data. Our main results are quantitative positivity and boundedness estimates for locally defined solutions. They combine into forms of new Harnack inequalities that are typical of fast diffusion equations. Such results are ne...

1991
Joan Daemen Antoon Bosselaers René Govaerts Joos Vandewalle

A method is described to generate collisions for the hash function FFT-Hash that was presented by Claus Schnorr at Crypto '91. A set of colliding messages is given that was obtained by this method.

Journal: :Math. Comput. 2014
Gang Bao Shui-Nee Chow Peijun Li Hao-Min Zhou

This paper is concerned with an inverse random source problem for the one-dimensional stochastic Helmholtz equation, which is to reconstruct the statistical properties of the random source function from boundary measurements of the radiating random electric field. Although the emphasis of the paper is on the inverse problem, we adapt a computationally more efficient approach to study the soluti...

2010
Jérôme Le Rousseau

We consider the first-order Cauchy problem ∂zu + a(z, x,Dx)u = 0, 0 < z ≤ Z, u |z=0 = u0, with Z > 0 and a(z, x,Dx) a k×k matrix of pseudodifferential operators of order one, whose principal part a1 is assumed symmetrizable: there exists L(z, x, ξ) of order 0, invertible, such that a1(z, x, ξ) = L(z, x, ξ) (−iβ1(z, x, ξ) + γ1(z, x, ξ)) (L(z, x, ξ))−1, where β1 and γ1 are hermitian symmetric and...

2008
Lei Fu

We calculate the local Fourier transformations for a class of Q l -sheaves. In particular, we verify a conjecture of Laumon and Malgrange ([L] 2.6.3).

2011
David S. Wise

K e y W o r d s a n d P h r a s e s : V L S I , s w i t c h i n g n e t w o r k s , d e l t a n e t w o r k s , omega n e t w o r k s , m u l t i p r o c e s s i n g . CR C a t e g o r i e s : 6 . 1 , 4 . 3 2 , 3 . 8 1 , 3 . 8 3 .

Journal: :EURASIP J. Adv. Sig. Proc. 2004
Colin P. Ratcliffe William J. Bagaria Sonia M. F. Garcia Richard P. Fahey

The type of signal studied in this paper is a periodic pulse, with the pulse length short compared to the period, and the signal is buried in noise. If standard techniques such as the fast Fourier transform are used to study the signal, the data record needs to be very long. Additionally, there would be a very large number of calculations. The rapid binary gage function was developed to quickly...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید