Acoustics, Speech, and Signal Processing, 1994. ICASSP-94., 1994 IEEE International Conference on

19-22 April 1994

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  • Bootstrap sampling applied to image analysis

    Publication Year: 1994, Page(s):VI/81 - VI/84 vol.6
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (359 KB)

    We present the bootstrap sampling techniques applied to some pattern recognition algorithms. Two important procedures in image analysis are tested: a statistical segmentation based on expectation-maximisation (EM) family algorithms and two methods of invariant features extraction for gray level images. In the first case, the results we obtain show that the bootstrap sample selection method gives b... View full abstract»

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  • Signal processing education in the French system

    Publication Year: 1994, Page(s):VI/61 - VI/63 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    This paper investigates the French system of signal processing education. At first a general description of the French system of electrical engineering education is presented. Then the particular case of signal processing studies is described by using an example of one of the French universities View full abstract»

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  • A short history of the bootstrap

    Publication Year: 1994, Page(s):VI/65 - VI/68 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (152 KB)

    A very brief account is given of the history of bootstrap methods in statistics, including early contributions made by Mahalanobis, Quenouille, Tukey, Barnard and Hartigan as well as Efron. The definition of bootstrap methods is addressed View full abstract»

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  • Multiple bootstrap tests and their application

    Publication Year: 1994, Page(s):VI/69 - VI/72 vol.6
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    We review bootstrap methods for testing statistical hypotheses. We begin with single hypothesis testing and give an example of its use. We then consider multiple testing based on Holm's step-down procedure and discuss how the bootstrap can incorporate relevant correlation and distributional characteristics. These techniques are applied to tests for zeros of transfer functions of linear systems at ... View full abstract»

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  • Bootstrapping coherency function

    Publication Year: 1994, Page(s):VI/77 - VI/79 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (132 KB)

    In estimating spectrum and coherency function smoothing techniques have been widely used. However, smoothing creates undesirable bias consequently. We suggest the bootstrap method for the estimation of the bias and propose a bias-corrected estimator. Confidence bands are also considered by using a bootstrap estimate of the standard deviation. Simulation study are carried out for two cases View full abstract»

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  • Multiple testing for seismic data using bootstrap

    Publication Year: 1994, Page(s):VI/89 - VI/92 vol.6
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB)

    Investigates the estimation of both the number of waves and of the wave parameters for wavefields in a geophysical application. A parametric method for wave parameter estimation in connection with a multiple test procedure is presented. The distribution of the corresponding test statistic for wideband data is approximated by the central limit theorem and alternatively by a bootstrap procedure. Fin... View full abstract»

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  • A new WDF three-port adaptor suitable for floating-point arithmetic and/or DSP implementations

    Publication Year: 1994, Page(s):VI/17 - VI/20 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    A new decomposed version of three-port adaptors for wave digital filters (WDFs) is proposed, which is especially suitable for floating-point arithmetic and for implementation on digital signal processors (DSPs). By using the proposed three-port adaptor, the concept of modified wave digital filters (MWDFs) is appropriately extended to WDFs involving any n-port adaptors (n is integer). The resulting... View full abstract»

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  • Jackknifing multiple-window spectra

    Publication Year: 1994, Page(s):VI/73 - VI/76 vol.6
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (312 KB)

    This paper describes some aspects of resampling multiple-window estimates of spectra and related functions in a time-series setting. We show that the jackknife variance of a log spectrum estimate is lower than that obtained by computing the variance directly, and describe a hybrid form with better performance than either. We also give some details on jackknifing line frequency parameters. Finally,... View full abstract»

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  • A bootstrap approach to estimating fractal dimensions

    Publication Year: 1994, Page(s):VI/85 - VI/88 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    This paper outlines a bootstrap approach to estimating the “correlation dimension” of a fractal measure, from a set of observations on that measure. An important example is estimating the dimension of the attractor of a chaotic system from a set of observations on that system. The method reduces the effects of dependence among the observations, is stable to minor variations in the proc... View full abstract»

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  • Discrete modelling of plasma equations with ion motion using technique of wave digital filters

    Publication Year: 1994, Page(s):VI/21 - VI/24 vol.6
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (200 KB)

    This paper shows how to solve a system of plasma equations consisting of Euler's and Maxwell's equation systems by using technique of wave digital filters. Since, in plasmas, the electromagnetic effect superposed in addition to the effect of thermal motion in the fluid, both Kirchhoff circuits derived from the equation systems have to be connected each other, which are transformed into well-known ... View full abstract»

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  • Multidimensional wave-digital principles: from filtering to numerical integration

    Publication Year: 1994, Page(s):VI/173 - VI/181 vol.6
    Cited by:  Papers (18)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (868 KB)

    Wave-digital principles, originally developed for one-dimensional filtering purposes, have later been extended to multidimensional filtering applications and have been shown to be applicable also to numerical integration of physically relevant ordinary and partial (thus multidimensional) differential equations of linear and nonlinear type. They are based on physical concepts such as Kirchhoff circ... View full abstract»

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  • STUDIO-monostatic backscatter sounder father of NOSTRADAMUS French O.T.H. radar project-new results

    Publication Year: 1994, Page(s):VI/109 - VI/112 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    In the late 1960s, two new techniques appeared, aimed at reducing the radiated peak power. The first technique was developed in the U.S., based on a bistatic system, using linear FMCW. The second technique was developed in France, a monostatic system using pulse code modulation and alternate transmit-receive periods. This technique is now used in the French OTH radar project NOSTRADAMUS. This pape... View full abstract»

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  • Bootstrapping autoregressions with infinite order

    Publication Year: 1994, Page(s):VI/97 - VI100 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (216 KB)

    We consider a stationary autoregressive process of infinite order and discuss bootstrap procedures for the autocovariance function and the spectral density. After fitting an autoregressive process of increasing order to the observed data and estimating the parameter of the process we obtain estimated residuals. Now we construct an autoregressive bootstrap process with innovations which are distrib... View full abstract»

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  • Adaptive wave digital fan filters

    Publication Year: 1994, Page(s):VI/25 - VI/28 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    Adaptive two-dimensional (2-D) fan filters based on least mean square algorithm and 2-D wave digital filter structure are presented. The weight updating equations as well as the equations for computing the gradient components of signals in two-dimensional wave digital filter adaptors are derived and specifically applied to wave digital quadrant and narrowband fan filters. Computer simulations are ... View full abstract»

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  • Fuzzy logic: issues, contentions and perspectives

    Publication Year: 1994
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (84 KB)

    There has been a rapid growth in the number and variety of applications of fuzzy logic. The successes of fuzzy logic have also generated a skeptical reaction. Most of the criticisms directed at fuzzy logic are rooted in a misunderstanding of what it is and/or a lack of familiarity with it. In many cases, what is not recognized is that the term fuzzy logic (FL) is actually used in two different sen... View full abstract»

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  • Noise behaviour in the modified Fourier transform for interferometric data inversion

    Publication Year: 1994, Page(s):VI/157 - VI/160 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB)

    Proposes a modified Fourier transform for the inversion of the visibility function acquired by an unidimensional interferometer observing the surface of the Earth from a low orbit. The inversion of the visibility function by the mean of the usual Fourier transform provides a profile of geometrically distorted brightness temperatures. A modified Fourier transform which takes into account the geomet... View full abstract»

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  • High frequency atmospheric noise mitigation

    Publication Year: 1994, Page(s):VI/101 - VI/104 vol.6
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (356 KB)

    The performance of high frequency (HF) radio communication and radar systems can be limited by noise generated by sources external to the receiving antenna. Below 10 MHz, atmospheric noise generated by worldwide thunderstorm activity tends to be the dominant natural source. We present an empirical analysis of atmospheric noise cancellation achieved by applying an adaptive sidelobe canceller to wid... View full abstract»

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  • “Digital signal processing with applications:” a new and successful approach to undergraduate DSP education

    Publication Year: 1994, Page(s):VI/49 - VI/52 vol.6
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (336 KB)

    The new approach to undergraduate DSP education at Purdue is based on a simple idea: emphasize applications. Students are assumed to have a significant exposure to sampling and discrete-time signals, systems, and transforms at the junior level. In the senior course, the traditional DSP topics of digital filter design, the DFT, radix-2 FFT's, and quantization are covered in the first five weeks of ... View full abstract»

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  • A review of signal processing education in Scotland

    Publication Year: 1994, Page(s):VI/29 - VI/32 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    This paper presents a background to the teaching of Signal Processing in Scottish universities, identifies commonality of undergraduate teaching programmes and contents, provides information on the key teaching syllabuses and on the relevant advanced final year options, as well as on postgraduate instructional courses. It also comments on current trends and future directions, and ends by posing a ... View full abstract»

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  • Numerical investigation of the Euler equations by means of wave digital filters

    Publication Year: 1994, Page(s):VI/1 - VI/4 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    A fluid dynamic system can be described by nonlinear partial differential equations (PDEs). Well suited for simulation purposes is a discrete passive dynamic system, which can be found using principles known from the theory of multidimensional (MD) wave digital filters (WDF). All major features of the original physical system (e.g. massive parallelism, local interdependencies, MD-passivity etc.) a... View full abstract»

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  • Location of a dragline bucket in space using machine vision techniques

    Publication Year: 1994, Page(s):VI/161 - VI/164 vol.6
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    Because a dragline bucket's rigging is flexible, its position cannot be inferred from knowledge of rope length and boom position only. Moreover, active devices cannot be placed on the bucket itself to sense position because of the risk of damage. This paper describes a new machine vision system which is being developed to sense bucket position remotely. It is based on a single camera observing the... View full abstract»

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  • Real time implementation of HMM speech recognition for telecommunications applications

    Publication Year: 1994, Page(s):VI/145 - VI/148 vol.6
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    This paper describes an implementation of connected word recognition using commercially available parallel processing DSPs. The recognition system uses continuous density HMMs for speaker independent recognition over a public switched network. It describes how the computationally intensive functions can be optimised for efficient real time implementation. Results of recognition accuracy are presen... View full abstract»

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  • Gaussian mixture model classifiers for machine monitoring

    Publication Year: 1994, Page(s):VI/133 - VI/136 vol.6
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB)

    We describe a statistical pattern-recognition approach to machine monitoring. The approach comprises a classification scheme using Gaussian mixture models (GMMs) that classifies features based on a time-frequency representation using the wavelet transform. The GMM trained with the EM algorithm has comparable flexibility with the multilayered perceptron in modeling nonstationary, multimodal machine... View full abstract»

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  • An overview of multiple-window and quadratic-inverse spectrum estimation methods

    Publication Year: 1994, Page(s):VI/185 - VI/194 vol.6
    Cited by:  Papers (12)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (728 KB)

    Presents examples, history, and a brief review of the theory of multiple-window and quadratic-inverse spectrum estimation methods for mixed harmonizable processes. In addition to the standard uses of making consistent non-parametric auto- and cross-spectrum estimates with jackknife confidence intervals and estimating periodic components in coloured noise, quadratic-inverse theory gives a time-freq... View full abstract»

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  • Jackknifed multiple-window spectra and coherence applied to seismic data

    Publication Year: 1994, Page(s):VI/93 - VI/96 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    Examines the variance of power spectra and magnitude squared coherences determined from local earthquake seismograms recorded synchronously on a small aperture seismic array. The multiple taper algorithm is used to calculate the spectra and coherences. Variances of these estimates are calculated with the jackknife technique, after transforming to a more normal distribution, and are compared with e... View full abstract»

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