1998/4

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Recent Submissions

Now showing 1 - 5 of 9
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    Study of 2-input 2-output Blind Signal Separation by Output Decorrelation
    (Společnost pro radioelektronické inženýrství, 1998-12) Machuca, E.; Sovka, Pavel; Davidek, V.
    The simulations and experiments representing the initial study of the output decorrelation approach to blind signal separation are presented in this paper. The definition of performance indexes for the evaluation and comparison of different algorithms are proposed. Two algorithms are compared. Some first results of real experiments are discussed.
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    Generalized Sampling Theorem for Bandpass Signals
    (Společnost pro radioelektronické inženýrství, 1998-12) Prokes, A.
    Bandpass time-continuos signals are shown being able to be uniquely expressed in terms of the samples gi(nTv) of the impulse responses gi(t) of m linear time-invariant systems with input f(t) sampled at 1/m Nyquist rate. Various known extensions of the sampling theorem can be regarded as special cases of the resulting generalized sampling expansion of f(t).
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    Speech Segmentation Using Bayesian Autoregressive Changepoint Detector
    (Společnost pro radioelektronické inženýrství, 1998-12) Cmejla, R.; Sovka, Pavel
    This submission is devoted to the study of the Bayesian autoregressive changepoint detector (BCD) and its use for speech segmentation. Results of the detector application to autoregressive signals as well as to real speech are given. BCD basic properties are described and discussed. The novel two-step algorithm consisting of cepstral analysis and BCD for automatic speech segmentation is suggested.
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    An Approach to 2D Wavelet Transform and Its Use for Image Compression
    (Společnost pro radioelektronické inženýrství, 1998-12) Vargic, R.
    In this paper is constructed a new type of two-dimensional wavelet transform. Construction is based on lifting scheme. We transform 1D wavelets with symmetrical factorisation to their 2D counterparts. Comparison to existing similar 2D wavelet constructions is given. Application for image compression is given using progressive (SP1HT) and classical type transform coder.
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    Rain Scattering and Co-ordinate Distance Calculation
    (Společnost pro radioelektronické inženýrství, 1998-12) Hajny, M.
    Calculations of scattered field on the rain objects are based on using of Multiple MultiPole (MMP) numerical method. Both bi-static scattering function and bi-static scattering cross section are calculated in the plane parallel to Earth surface. The co-ordination area was determined using the simple model of scattering volume [1]. Calculation for frequency 9.595 GHz and antenna elevation of 25° was done. Obtained results are compared with calculation in accordance to ITU-R recommendation.