An accurate quantitative definition of financial crisis requires a universal and robust scale for measuring market shocks. Following Zumbach et al. (2000) and Maillet et Michel (2003), we propose a new quantitative measure of financial disturbances, which captures the heterogeneity of investor horizons – from day traders to pension funds. The indicator resides on a multi-resolution analysis of ...

Anisotropic wavelet packets present a flexible transform with interesting properties and applications. While certain aspects of this transform have been investigated in conjunction with applications, this paper aims at providing a basic theoretical framework for working with anisotropic wavelet packets. Random decompositions are developed which have distributions with different average decompos...

The Empirical mode decomposition (EMD) is an adaptive decomposition of the data, as is the Wavelet packet best basis decomposition. This work present the first attempt to examining the use of EMD for image compression purposes. The Intrinsic Mode Function (IMF) and their Hilbert spectra are compared to the wavelet basis and the wavelet packet decompositions expanded in each of its best bases on...

We explore the role that the wavelet packet transform can play in increasing multiple access communication throughput via waveform design and receiver design. Wavelet packets ooer a exible framework which allows us to select and reene signature waveforms at intermediate time-frequency levels leading to the development of eecient methods for near optimal receiver implementation. The optimal rece...

Alternative ways to represent speaker’s voice individuality are studied for the task of speaker verification. We exploit a set of orthonormal bases provided by wavelet packets that allow an effective manipulation of the frequency subbands according to the critical bands concept. Novel wavelet packet based sets of speech features are contrasted with existing wavelet features as well as with the ...

Optimum time-frequency decompositions are very useful in audio coding applications, because the signal energy can be maximally concentrated even for the wide variety of audio signal characteristics. Moreover, this signal representation is particularly well suited for a perceptual weighting of the quantization noise. The well known tree structure of cascaded 2-channel filterbanks allows a very f...

We present in this paper a wavelet packet based QRS complex detection algorithm. Our proposed algorithm consists of a particular combination of two vectors obtained by applying a designed routine of QRS detection process using ‘haar’ and ‘db10’ wavelet functions respectively. The QRS complex detection routine is based on the histogram approach where our key idea was to search for the node with ...

Detecting and recognizing human faces automatically in digital images strongly enhance content-based video indexing systems. In this paper, a novel scheme for human faces detection in color images under nonconstrained scene conditions, such as the presence of a complex background and uncontrolled illumination, is presented. Color clustering and filtering using approximations of the YCbCr and HS...