A model for an infrared (IR) flame detection system using artificial neural networks (ANN) is presented. The joint timefrequency analysis (JTFA) in the form of a Short-Time Fourier Transform (STFT) is used for extracting relevant input features for a set of ANNs. Each ANN is trained using the backpropagation conjugate-gradient (CG) method to distinguish all hydrocarbon flames from a particular ...

The vocal tract length (VTL) is one of the variabilities that speaker-independent automatic speech recognition (ASR) systems encounter. Standard methods to compensate for the effects of different VTLs within the processing stages of the ASR systems often have a high computational effort. By using an appropriate warping scheme for the frequency centers of the timefrequency analysis, a change in ...

Current multimedia technologies call for efficient ways of representing signals. We review several efficient methods for signal representation, emphasizing potential applications in signal compression and denoising. We pay special attention to the representations which are adapted to “non-stationary” features of signals, in particular the classes of bilinear representations, and their approxima...

In this letter, we develop a novel network-wide traffic analysis methodology, named Stable Principal Component Pursuit with Time-Frequency Constraints (SPCP-TFC), for extracting the baseline of a traffic matrix. Following a refined traffic matrix decomposition model, we present new timefrequency constraints to extend Stable Principal Component Pursuit (SPCP), and design an efficient numerical a...

Attack transients or simply attacks, are zones of short duration and fast variation of the sound signal short-time spectrum such as at the attack of percussion instruments. There are many motivations for attack detection and modeling; improving general analysis techniques is one of them. A method and a program have been developed for detection, modeling and reconstruction of attacks. It is base...

The short-time Fourier transform (STFT) is a timefrequency representation widely used in audio signal processing. Recently it has been shown that not only the amplitude, but also the phase of this representation can be successfully exploited for improved analysis and processing. In this paper we describe a rather peculiar pole phenomenon in the phase derivative, a recurring pattern that appears...

We present analytical and experimental results demonstrating a conceptual break through on how to overcome the fundamental timefrequency bandwidth limit (or spectral superresolution) for a light pulse in traditional and heterodyne spectrometry. This can be achieved either by a de-convolution process suggested by analytical method or by heterodyne method, which we demonstrate.

In this paper we study chaotic signals generated from Chua’s circuit: in particular we concentrate on the well known spiral attractor. Chaotic signals have a nonstationary nature, and hence the classical Fourier spectrum turns out to be inadequate for the analysis. Instead of it we use TimeFrequency Distributions, a powerful set of tools specifically designed for nonstationary signal analysis. ...

Wigner Ville Transform is introduced as a suitable tool for the analysis of the speech signal, as it allows making a correct representation of the signal energy. First, we give a mathematical formulation of the Wigner Ville Transform of a stationary model of voiced speech. The speech model is expressed as a linear combination of the harmonic frequencies of fundamental frequency of the voiced sp...

We introduce a new and simple technique for human gait classification based on the time-frequency analysis of radar data. The focus is on the classification of arm movements to discern free vs. confined arm swinging motion. The latter may arise in hostage situation or may be indicative to carrying objects with one or both hands. The motion signatures corresponding to the arm and leg movements a...