The continuous wavelet transform may be enhanced by deconvolution with the wavelet response function. After correcting for the coneof-influence, the power spectral density of the solar magnetic record as given by the derectified yearly sunspot number is calculated, revealing a spectrum of odd harmonics of the fundamental Hale cycle, and the integrated instant power is compared to a reconstructi...

The wavelet transform theory is used to motor fault diagnosis in this paper, considering its characteristics of multi-resolution and stronger feature extraction ability than Fourier. The paper emphasizes de-noising and eliminating the singular value point of the wavelet transform in the nonstationary signal. And it makes a detailed and in-depth analysis about how to detect the frequency compone...

The aim of this paper is to present a new approach to spectral representation using sums of Gaussian distributions. Sums of Gaussians provide an intuitive representation for frequency bands of a signal spectrum as well as formant regions. The representation of spectral envelopes using Gaussian parameters {a, μ, σ} simplifies the expression of important tasks such as frequency warping and forman...

In today's multicarrier modulation systems such as orthogonal frequency division multiplexing (OFDM) or discrete multitone (DMT), modulation is accomplished digitally by the use of the inverse discrete Fourier transform (IDFT). Instead of the IDFT, any other orthogonal transform can be used. In this paper a multicarrier scheme based on extended lapped transforms (ELT) is investigated. With the ...

This article is concerned with a version of photoacoustic computed tomography, that uses line detectors (instead of point-like ones) for the recording of induced acoustical data. The three dimensional imaging problem, consisting in reconstructing the unknown density function from recorded data, is reduced to a series of two dimensional problems: First, the initial data of the two dimensional wa...

This paper concerns the derivation of kinetic models for high frequency scalar wave fields propagating in random media. The kinetic equations model the propagation in the phase space of the energy density of a wave field or the correlation function of two wave fields propagating in two possibly different media. Dispersive effects due to e.g. spatial and temporal discretizations, which are model...

Flood hedging reservoir operation is when a pre-storm release creates a small flood downstream to reduce the likelihood of a more damaging but uncertain larger flood in the future. Such pre-storm releases before a flood can increase reservoir storage capacity available to capture more severe flood flows, but also can immediately increase downstream flood damage and reduce stored water supply. T...

A new wavelet transform (WT) is introduced based on the fractional properties of the traditional Fourier transform. The new wavelet follows from the fractional Fourier order which uniquely identifies the representation of an input function in a fractional domain. It exploits the combined advantages of WT and fractional Fourier transform (FrFT). The transform permits the identification of a tran...

Frequency estimation of single-tone complex sinusoid is a fundamental problem in signal processing. An efficient way to estimate the frequency is to directly calculate the frequency from three discrete Fourier transform coefficients in the neighborhood of peak magnitude spectrum. Because of the approximation used in the calculation, these direct estimators exhibit non-uniform biases. In this pa...

In fields ranging from radio astronomy to magnetic resonance imaging, Fourier inversion of data not falling on a Cartesian grid has been a prbblem. As a result, multiple algorithms have been created for reconstructing images from nonuniform frequency samples. In the technique known as gridding, the data samples are weighted for sampling density and convolved with a finite kernel, then resampled...