1999/2
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- ItemFuzzy Stack Filters for Image Processing(Společnost pro radioelektronické inženýrství, 1999-06) Marchevsky, S.; Stupak, Cs.This paper is oriented to filtering by fuzzy stack filter of monochromatic images distorted with impulsive noise. Fuzzy stack filter is acquired by extension of stack filters by means of fuzzy logic. Adding some parameters to this filter, that are adjusted by neural adaptation algorithm, is obtained the new class of filters, so-called fuzzy rank-order filters. This class of filters is compared with other well known filters as stack filters and neural stack filters.
- ItemPolyphase Order Analysis Based on Convolutional Approach(Společnost pro radioelektronické inženýrství, 1999-06) Drutarovsky, M.The condition of rotating machines can be determined by measuring of periodic frequency components in the vibration signal which are directly related to the (typically changing) rotational speed. Classical spectrum analysis with a constant sampling frequency is not an appropriate analysis method because of spectral smearing. Spectral analysis of vibration signal sampled synchronously with the angle of rotation, known as order analysis, suppress spectral smearing even with variable rotational speed. The paper presents optimised algorithm for polyphase order analysis based on non power of two DFT algorithm efficiently implemented by chirp FFT algorithm. Proposed algorithm decreases complexity of digital resampling algorithm, which is the most complex part of complete spectral order algorithm.
- ItemMotion Analysis Based on Invertible Rapid Transform(Společnost pro radioelektronické inženýrství, 1999-06) Gamec, J.; Turan, J.This paper presents the results of a study on the use of invertible rapid transform (IRT) for the motion estimation in a sequence of images. Motion estimation algorithms based on the analysis of the matrix of states (produced in the IRT calculation) are described. The new method was used experimentally to estimate crowd and traffic motion from the image data sequences captured at railway stations and at high ways in large cities. The motion vectors may be used to devise a polar plot (showing velocity magnitude and direction) for moving objects where the dominant motion tendency can be seen. The experimental results of comparison of the new motion estimation methods with other well known block matching methods (full search, 2D-log, method based on conventional (cross correlation (CC) function or phase correlation (PC) function) for application of crowd motion estimation are also presented.
- ItemMedium Access Control Protocols for Wireless ATM(Společnost pro radioelektronické inženýrství, 1999-06) Dobos, L.; Juhar, J.; Cizmar, A.The most crucial issues in the conception of an efficient wireless ATM network are the design of the physical layer, data link layer. Medium Access Control (MAC) protocol and mobility management functions. In this article we focus on MAC protocols, namely on requirements for MAC protocols and on basic concepts of TDMA and CDMA based one. For illustration we consider with Time Division Duplex (TDD) as well as Frequency Division Duplex (FDD).
- ItemInteractive Progressive Image Transmission(Společnost pro radioelektronické inženýrství, 1999-06) Matus, E.; Levicky, D.In progressive image transmission (PIT) the image is transmitted progressively i.e. the low detail image is transmitted as first followed by transmission of detail signals. In our contribution we consider interactivity in the PIT. For example, the observer could specify image regions of highest interest (ROI). In this case, the image transmission should be optimised with respect to the ROI. The definition of objective criterion for interactive PIT is made in this paper as first. The spatial signal decomposition is derived with respect to this criterion. Wavelet transform of spatial components is used. At the end demonstration of proposed algorithm is made.