The condition of an inaccessible gear in an operating machine can be monitored using the vibration signal of the machine measured at some convenient location and further processed to unravel the significance of these signals. Demodulation is an important issue in gearbox fault detection. Non-stationary modulating signals increase difficulties of demodulation. Though wavelet packet transform has...

The existence of recorded accelerograms to perform dynamic inelastic time history analysis is of the utmost importance especially in near-fault regions where directivity pulses impose extreme demands on structures and cause widespread damages. But due to the scarcity of recorded acceleration time histories, it is common to generate proper artificial ground motions. In this paper an alternative ...

Ambient vibration tests are conducted widely to estimate the modal parameters of a structure. The work proposes an efficient wavelet-based approach to determine the modal parameters of a structure from its ambient vibration responses. The proposed approach integrates the time series autoregressive (AR) model with the stationary wavelet packet transform. In addition to providing a richer decompo...

This paper introduces a codec scheme for compressing the control and feedback signals in networked control and teleoperation systems. The method makes use of Wavelet Packet Transform (WPT) and Inverse Wavelet Packet Transform (IWPT) for coding and decoding operations, respectively. Data compression is carried out in low-pass filter output by reducing the sampling rate, and in high-pass filter o...

In this paper, a two-stage dual tree complex wavelet packet transform (DTCWPT) based speech enhancement algorithm has been proposed, in which a speech presence probability (SPP) estimator and a generalized minimum mean squared error (MMSE) estimator are developed. To overcome the drawback of signal distortions caused by down sampling of wavelet packet transform (WPT), a two-stage analytic decom...

This paper presents an embedded wavelet packet image coding algorithm which is based on context classification and quadtree ordering (CCAQO). To match up well with the quadtree-based embedded coder, a new cost function for the best basis selection is adopted in discrete wavelet packet transform (DWPT). In addition, combined with the structure of the best wavelet packet basis, a complete quadtre...

In this paper a novel multicarrier modulation system called Complex Wavelet Packet Modulation (CWPM) has been proposed. It is based on using the Complex Wavelet Transform (CWT) together with the Wavelet Packet Modulation (WPM). The proposed system has been tested for communication over flat and frequency selective Rayleigh fading channels and its performance has been compared with some other mu...

A non-uniform speech segmentation method based on wavelet packet transform is used for the localisation of phoneme boundaries. Eleven subbands are chosen by applying the mean best basis algorithm. Perceptual scale is used for decomposition of speech via Meyer wavelet in the wavelet packet structure. A real valued vector representing the digital speech signal is decomposed into phone-like units ...

In this paper, a wavelet packet decomposition (WPD) based real-time transcale linearquadratic-Gaussian (LQG) tracking control algorithm is given for a class of discrete stochastic systems, which is developed with the state-space models of wavelet packet coefficients at the coarsest scale decomposition layer established by Haar WPD. The WPD-based transcale control algorithm provides a compromise...

Compression of speech from the TIMIT corpus was investigated for several transform domain methods coding near-best and best bases from cosine and wavelet packet transforms. Satisficing (suboptimizing) search algorithms for selecting near-best bases were compared with optimizing algorithms for best bases in these adaptive tree-structured transforms. Experiments were performed on several hundred ...