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Time-Frequency and Time-Scale Analysis, 1992., Proceedings of the IEEE-SP International Symposium

Date 4-6 Oct. 1992

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  • Proceedings of the IEEE-SP International Symposium Time-Frequency and Time-Scale Analysis (Cat.No.92TH0478-8)

    Publication Year: 1992
    Request permission for commercial reuse | PDF file iconPDF (107 KB)
    Freely Available from IEEE
  • Random wavelet representation of unvoiced speech

    Publication Year: 1992, Page(s):41 - 44
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    The different types of speech noise are reviewed together with their first-order statistics. A theoretical framework is formulated for speech noise analysis in terms of time-frequency energy concentrations (spectral peaks, amplitude and phase modulation). This framework is based on the linear acoustic theory of speech production, and on the theory of random modulation. A synthesis scheme using ran... View full abstract»

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  • A functional model of the early auditory system

    Publication Year: 1992, Page(s):45 - 48
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (264 KB)

    An analytical tractable model of the early auditory system is proposed based on the wavelet representation and lateral inhibitory networks (LINs). From a theoretical point of view, LIN processing can be interpreted as a sampling process that preserves information only at the extrema, or equivalently, the zero crossings of the first derivative of the cochlear filter outputs. For each channel, the z... View full abstract»

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  • The flexible design of compactly supported wavelets

    Publication Year: 1992, Page(s):319 - 322
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (248 KB)

    A time-domain approach to the design of compactly supported wavelets is considered. The time-domain formulation has resulted in a unified design approach for uniform, nonuniform, low-delay, and efficient analysis-synthesis filter banks. Because of the generality of the framework, regularity and phase conditions can easily be imposed on the wavelet. Because the design procedure can be used for nonu... View full abstract»

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  • An auditory motivated time-scale signal representation

    Publication Year: 1992, Page(s):49 - 52
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (276 KB)

    A time-scale representation of (acoustic) signals, motivated by the structure of the mammalian auditory system, is presented. Drawing from the theory of irregular sampling and frames, a theoretical framework is developed in which iterative algorithms for reconstruction are constructed. Numerical examples are included which illustrate the validity of such a representation for new and effective meth... View full abstract»

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  • Window matching in the time-frequency plane and the adaptive spectrogram

    Publication Year: 1992, Page(s):87 - 90
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    Aspects of generating spectrograms which may be used in the preliminary steps of time-frequency analysis are discussed. It is shown that the major problem with the application of the spectrogram is its nonunique nature, i.e., the use of an arbitrary window for analysis. The concept of window matching is introduced, whereby the selection of the window used for analysis depends on the instantaneous ... View full abstract»

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  • Multi-signal time-frequency model fitting using an approximate maximum likelihood algorithm

    Publication Year: 1992, Page(s):269 - 272
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    By taking advantage of the moderate computational demand of the recently developed approximate maximum likelihood (AML) algorithms, it is shown that with algorithm refinement linear parametric model-fitting can be extended to a wide range of complex data interpretation tasks, including time-frequency and time-scale analyses. A novel version of the IMP (incremental multiparameter) AML algorithm (us... View full abstract»

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  • Registration and matching using orthogonal wavelets

    Publication Year: 1992, Page(s):567 - 570
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (236 KB)

    Algorithms for applying the orthogonal wavelet pyramid representation in matching and registration for pattern recognition are presented. They compensate for lack of translation invariance by beginning from feasible points at a coarse level and by tracking registrations through ever finer resolution levels, and they quickly compare coarse representations of candidates for matching against library ... View full abstract»

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  • Multiple geometrical filters for 3D scale-invariant image representation of planar objects

    Publication Year: 1992, Page(s):531 - 534
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    A low-level approach for 3-D invariant recognition of planar object from a centered monocular view is presented. The proposed scheme uses a distributed bank of filters that perform geometrical mapping on spatial image domain to generate a multidimensional (4-D) description. This image representation achieves invariance to 2-D rotation, scaling and perspective projection. Invariant classification a... View full abstract»

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  • Space-time-scale analysis of electromagnetic waves

    Publication Year: 1992, Page(s):209 - 212
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (340 KB)

    The previously defined analytic-signal transform is used to extend electromagnetic waves from real space-time to complex space-time. This leads naturally to a family of elementary conformal wavelets, which can all be obtained by applying conformal transformations of space-time to a basic wavelet. The basic wavelet, is uniquely determined by analyticity considerations. These wavelets are parametriz... View full abstract»

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  • The ambiguity function of a linear signal space and its application to maximum-likelihood range/Doppler estimation

    Publication Year: 1992, Page(s):489 - 492
    Cited by:  Papers (3)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    The concept of the ambiguity function (AF) is extended to linear signal spaces. Some properties of the AF of a linear signal space, its relations with other space representations, and the results obtained for some specific signal spaces are discussed. It is shown that the AF of a signal space describes the performance of the maximum likelihood (ML) range/Doppler estimator for a slowly fluctuating ... View full abstract»

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  • The design of compactly supported orthonormal wavelets with integer scaling factors

    Publication Year: 1992, Page(s):323 - 326
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (284 KB)

    It has been shown that discrete-time orthonormal wavelet decompositions are related to lossless perfect reconstruction (PR) multirate filter banks except that such filters are not generally designed with wavelet regularity considerations in mind. The authors present a method, based on the design of M-band PR filters, to generate orthonormal wavelets with arbitrary integer scaling factor ... View full abstract»

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  • Scale based coding of digital communication signals

    Publication Year: 1992, Page(s):455 - 458
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB)

    Multiple-access communication schemes using wavelet-based orthogonal codes are described. In the simplest such scheme, the message bit stream in each channel is encoded as a sequence of time-shifted replicates of a mother wavelet symbol at a particular scale. Different channels use the same wavelet symbol but a different scale. The messages are decodable if the time-shifted and dilated replicates ... View full abstract»

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  • Adapted waveform libraries in magnetic resonance imaging

    Publication Year: 1992, Page(s):133 - 136
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (324 KB)

    The authors consider several implementation issues associated with wavelet encoding, an application of wavelet techniques to signal acquisition in magnetic resonance imaging (MRI). A quantitative analysis of the signal-to-noise limitations of this method is presented. It is found that the localized support features of wavelet bases which provide desirable properties of imaging speed and artifact r... View full abstract»

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  • Signal-dependent kernel for reduction of time-domain cross terms in time-frequency distributions

    Publication Year: 1992, Page(s):245 - 248
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (164 KB)

    A signal-dependent tapering function which is able to reduce time-domain cross terms for the class of impulsive signals is introduced. The reverse-correlation function magnitude is constrained to suppress increases away from the origin. In combination with the cone-shaped kernel approach, the resulting time-frequency distribution (TFD) demonstrates a reduction in both the time- and frequency-domai... View full abstract»

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  • A complete parametrization of 2D nonseparable orthonormal wavelets

    Publication Year: 1992, Page(s):55 - 58
    Cited by:  Papers (7)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    The problem of constructing compactly supported orthonormal multidimensional (k-D) nonseparable wavelets is considered. A complete solution to the problem of parametrizing all possible two-dimensional (2-D) wavelets having arbitrary degree of regularity is given. These results can be seen as a generalization of the Daubechies (1988) wavelets in two dimensions and go beyond those specific ... View full abstract»

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  • The design of signal dependent time-frequency kernels by McClellan transformation

    Publication Year: 1992, Page(s):91 - 94
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (236 KB)

    A McClellan transformation 2-D filter design method is used for designing a signal dependent time-frequency (t-f) kernel. This method is amenable to t-f kernel constraints, which do not commonly arise when filtering signals in image and array processing applications. The two parts of the McClellan transformation method (the one-dimensional filter and the linear transformation) provide a mechanism ... View full abstract»

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  • Optimal databased complex demodulation for evolutionary spectra

    Publication Year: 1992, Page(s):273 - 276
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    Complex demodulation of evolutionary spectra is formulated as a two-dimensional kernel smoother in the time-frequency domain. A tapered Fourier transform is calculated, and the log-spectral estimate is smoothed. As the characteristic widths of the kernel smoother increase, the bias from temporal and frequency averaging increases while the variance decreases. The demodulation parameters are chosen ... View full abstract»

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  • Chemical shift MR imaging using oscillating gradient fields-an approach by the short-time Fourier transform

    Publication Year: 1992, Page(s):571 - 574
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    The author describes an approach to the problem of chemical-shift imaging using the short-time Fourier transform and the wavelet. When point sources of different chemical-shift values are measured with varying gradient field, these points travel along different loci in the instantaneous frequency vs. time diagram. Following the locus of a chemical-shift component of interest, the spatial distribut... View full abstract»

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  • Vibration analysis of spatial systems by stationary and nonstationary regimes

    Publication Year: 1992, Page(s):361 - 364
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (140 KB)

    Passenger and goods elevators require hoist mechanism which avoid resonance vibrations. A method of investigating and diminishing vibrations, based on amplitude-time and amplitude-frequency characteristics of an elevator system is reported. A dynamic elevator model with 22 degrees of freedom is used in the analysis. It is found that the dynamic models, differential equations, and methods used are ... View full abstract»

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  • Limited angle tomography via multiresolution analysis and oversampling

    Publication Year: 1992, Page(s):215 - 218
    Cited by:  Papers (1)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (260 KB)

    A method is presented for reconstructing a function from its line integrals. This problem arises in imaging whenever the physical constraints of the system prohibit the gathering of the line integrals over the angles -π/2<θ<0. The first portion of the algorithm decomposes the limited angle operator L into a tensor product structure that allows an efficient calculation of it... View full abstract»

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  • Famlet, to be or not to be a wavelet?

    Publication Year: 1992, Page(s):335 - 338
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    A class of orthogonal time domain functions called famlets is introduced. Famlets are produced from their frequency domain representatives by using the inverse Fourier transform. The basic theory behind famlets and the famlet transform associated with them is formulated, and their usage in nonuniform resolution spectrum analysis is described. The similarities and dissimilarities of famlets and wav... View full abstract»

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  • The ambiguity function for broadband signals with application to objects undergoing non-uniform motion

    Publication Year: 1992, Page(s):493 - 496
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (212 KB)

    An alternative ambiguity function for broadband signals is derived and discussed. An example of the broadband waveform for a Gaussian signal that is reflected from a reflecting surface undergoing a constant acceleration is presented. The problem of reconstruction of the law of motion from the ambiguity function is considered View full abstract»

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  • Instantaneous scale and the short-time scale transform

    Publication Year: 1992, Page(s):383 - 386
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    The concept of instantaneous scale, ci, is developed and it is shown that it is given by ci=tØ'(t) where Ø'( t) is the derivative of the phase of the signal. Formulas for average scale, scale bandwidth, and scale group delay are obtained. The scale transform, the short time scale transform, the analytic scale signal, ... View full abstract»

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  • A new time-frequency distribution and its application to speech signal processing

    Publication Year: 1992, Page(s):417 - 420
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (184 KB)

    A kernel function for the time-frequency distribution of Cohen's (1989) class, which is the product of the Choi-Williams (1989) and the Margenau-Hill (1961) kernels, is proposed. Specific types of signal (sinusoidal signals, chirp signals and others) are analyzed using the distribution and compared with results for the Wigner-Ville and the Choi-Williams distributions. It is found that the present ... View full abstract»

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