Now showing items 1-9 of 9

  • Detecting Periodic Behavior in Nonstationary Signals 

    Venkatachalam, Vidya; Aravena, Jorge.L. (1998-10-20)
    This paper presents results on the multiresolution analysis of nonstationary signals with the objective of detecting underlying periodic phenomena. Wavelet packet analysis with coefficient thresholding is the basis for the ...
  • Enhanced Pseudo Power Signatures for Nonstationary Signal Classification: The Projector Approach 

    Venkatachalam, Vidya; Aravena, Jorge.L. (1999-05-01)
    The classification of nonstationary signals of unknown duration is of great importance in areas like oil exploration, moving target detection, and pattern recognition. In an earlier work, we provided a solution to this ...
  • Enhanced signatures for event classification: The projector approach 

    Venkatachalam, Vidya; Aravena, Jorge.L. (1998-10-01)
    The classification of nonstationary signals of unknown duration is of great importance in areas like oil exploration, moving target detection, and pattern recognition. In an earlier work, we provided a solution to this ...
  • Multiscale SAR Image Segmentation using Wavelet-domain Hidden Markov Tree Models 

    Venkatachalam, Vidya; Choi, Hyeokho; Baraniuk, Richard G. (2000-04-01)
    We study the segmentation of SAR imagery using wavelet-domain Hidden Markov Tree (HMT) models. The HMT model is a tree-structured probabilistic graph that captures the statistical properties of the wavelet transforms of ...
  • Nonstationary signal classification using pseudo power signatures 

    Venkatachalam, Vidya; Aravena, Jorge.L. (1998-06-20)
    This paper deals with the problem of classification of nonstationary signals using signatures which are essentially independent of the signal length. We develop the notion of a separable approximation to the Continuous ...
  • Nonstationary signal classification using pseudo power signatures: The Matrix SVD Approach 

    Aravena, Jorge.L.; Venkatachalam, Vidya (1999-12-20)
    This paper deals with the problem of classification of nonstationary signals using signatures which are essentially independent of the signal length. This independence is a requirement in common classification problems ...
  • Nonstationary Signal Enhancement Using The Wavelet Transform 

    Venkatachalam, Vidya; Aravena, Jorge.L. (1996-03-20)
    Conventional signal processing typically involves frequency selective techniques which are highly inadequate for nonstationary signals. In this paper, we present an approach to perform time-frequency selective processing ...
  • Optimal parallel 2-D FIR digital filter with separable terms 

    Venkatachalam, Vidya; Aravena, Jorge.L. (1997-05-01)
    This paper completely solves the optimal Weighted Least Mean Square (WLMS) design problem using sums of separable terms. For any fixed number of separable terms (less than or equal to the rank of the unconstrained solution), ...
  • Pseudo Power Scale Signatures: Frequency Domain Approach 

    Venkatachalam, Vidya; Aravena, Jorge.L. (2000-03-01)
    In an earlier work, we introduced a new form of signal representation called the <b><i>pseudo power signature (PPS)</i></b> that was essentially independent of the duration of the signal. The signatures were obtained based ...