Numerical method using filter banks for vibroacoustic analysis in the medium frequency domain

1998 ◽  
Vol 103 (5) ◽  
pp. 2929-2929
Author(s):  
Sylvie Gorog ◽  
Philippe Micheau
Keyword(s):  
Numerical Method ◽  
Frequency Domain ◽  
Filter Banks ◽  
Medium Frequency

Perfect-translation-invariant variable-density complex discrete wavelet transform

2014 ◽  
Vol 12 (04) ◽  
pp. 1460001 ◽  
Author(s):  
Hiroshi Toda ◽  
Zhong Zhang ◽  
Takashi Imamura
Keyword(s):  
Frequency Domain ◽  
Frequency Band ◽  
Time Domain ◽  
Wavelet Transforms ◽  
Filter Banks ◽  
Wavelet Packet ◽  
Discrete Wavelet ◽  
Translation Invariance ◽  
Logarithmic Scale ◽  
The Time Domain

The theorems giving the conditions for discrete wavelet transforms (DWTs) to achieve perfect translation invariance (PTI) have already been proven, and based on these theorems, the dual-tree complex DWT and the complex wavelet packet transform, achieving PTI, have already been proposed. However, there is not so much flexibility in their wavelet density. In the frequency domain, the wavelet density is fixed by octave filter banks, and in the time domain, each wavelet is arrayed on a fixed coordinate, and the wavelet packet density in the frequency domain can be only designed by dividing an octave frequency band equally in linear scale, and its density in the time domain is constrained by the division number of an octave frequency band. In this paper, a novel complex DWT is proposed to create variable wavelet density in the frequency and time domains, that is, an octave frequency band can be divided into N filter banks in logarithmic scale, where N is an integer larger than or equal to 3, and in the time domain, a distance between wavelets can be varied in each level, and its transform achieves PTI.

Resonator-based filter-banks for frequency-domain applications

1991 ◽  
Vol 38 (10) ◽  
pp. 1145-1159 ◽  
Author(s):  
M. Padmanabhan ◽  
K. Martin
Keyword(s):  
Frequency Domain ◽  
Filter Banks
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