Large numbers of vibration signals of wood-based panels are unsteady and complicated, which means that detection can be difficult. The wavelet transform is an effective method to detect these signals, which are otherwise difficult to detect using the Fast Fourier Transform (FFT). This paper presents a study on nondestructive detection of bubble defects seen in poplar laminated veneer lumber (LV...

In this paper, it is shown that the higher compression performance of biorthogonal wavelet filters over orthogonal wavelet filters is the combined effect from (1) the asymmetry of the frequency responses of the biorthogonal wavelet filters and (2) the non-flat spectra of the signals to be decomposed. Based upon this observation, an improved wavelet packet decomposition method for natural images...

ABSTRACT: For analyzing non-linear and non-stationary signals Empirical Mode Decomposition (EMD) is introduced as an adaptive method like wavelet packet best basis decomposition. Huang et. al introduced the empirical mode decomposition (EMD) in signal processing in 1998. In this communication we investigated the performance of video denoising using bi-dimensional EMD along with wavelet threshol...

Wavelet packets have been applied in order to compensate the speech signal to improve the intelligibil-ity for a common hearing impairment known as recruitment of loudness, a sensorineural hearing loss of cochlear origin. We present an architecture that allows selection of the best decomposition tree for each patient , in order to apply this wavelet-packet based para-metric compression algorithm.

High-speed automatic weapons play an important role in the field of national defense. However, current research on reliability analysis of automaton principally relies on simulations due to the fact that experimental data are difficult to collect in real life. Different from rotating machinery, a high-speed automaton needs to accomplish complex motion consisting of a series of impacts. In addit...

The main objective of this paper is to use ant optimized neural networks to generate artificial earthquake records. In this regard, training accelerograms selected according to the site geology of recorder station and Wavelet Packet Transform (WPT) used to decompose these records. Then Artificial Neural Networks (ANN) optimized with Ant Colony Optimization and resilient Backpropagation algorith...

A simple construction of an orthonormal basis starting with a so called mother wavelet, together with an efficient implementation gained the wavelet decomposition easy acceptance and generated a great research interest in its applications. An orthonormal basis may not, however, always be a suitable representation of a signal, particularly when time (or space) invariance is a required property. ...

In this paper, we propose an audio coder for high quality low bit-rate applications based on the wavelet-packet transform. The primary goal of the proposed coder will be to combine high quality reconstructed audio with shorter delay than existing methods while keeping the bit rate low. Present audio coders, such as MPEG, are capable of transparent or near-transparent monophonic CD quality at 12...

We show in this paper two ways to combine wavelet packets and total variation based deblurring methods. For this purpose, we first recall that it is possible to approximate a convolution by mean of an operator diagonal in a wavelet packet basis. Then, we show two possibilities, which uses this property, for combining wavelet packets and total variation approaches. We then show on experiments th...

We have used wavelets and wavelet packets to analyse, model and compute turbulent flows. The theory and open questions encountered in turbulence are presented. The wavelet-based techniques that we have developed to study turbulence are explained and the main results are summarized.