2000/1

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    Investigation of predictability of Chaotic Signals
    (Společnost pro radioelektronické inženýrství, 2000-04) Sebesta, V.
    Variables and functions for expressing quality of the prediction of the chaotic signal can serve as tools for simplified but useful description of the chaotic signal. In this paper, the known generation mechanism of chaos is used as a predictor but using the perturbed signal as an input. Prediction performance of the predictor is compared with the estimate of the predictability based on a mutual information between known quantities and a predicted value. mentioned two methods of investigation have different requirements for a priori knowledge of chaos. Certain constraints are given in consequence of an imperfection of numerical calculations and computer simulations.
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    VHDL Model of Electronic-Lock System
    (Společnost pro radioelektronické inženýrství, 2000-04) Vlcek, K.; Bannister, B. R.; Miklik, D.; Bell, I. M.; Bartsch, E.; Noga, J.
    The paper describes the design of an electronic-lock system which was completed as part of the Basic VHDL course in the Department of Control and Measurement Faculty of Electrical Engineering and Informatics, Technical University of Ostrava, Czech Republic in co-operation with the Department if Electronic Engineering, University of Hull, Great Britain in the frame of TEMPUS project no. S_JEP/09468-95.
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    AN Adaptive Control of LUM Smoother
    (Společnost pro radioelektronické inženýrství, 2000-04) Lukac, R.
    In this paper is presented a new design of LUM smoother. The LUM smoother, a subclass of lower-upper-middle (LUM) filters is used in smoothing image and signal applications. This filter very well can suppress impulsive noise and preserve signal details, simultaneously. It is achieved by simply varying the filter parameter for smoothing. However, the tuning parameter for smoothing is fixed for the whole image. A new design is based on adaptive controlled level of the smoothing. The analysis of new methods is presented. Performance of the proposed methods is evaluated through subjective and objective criteria and compared with the traditional LUM smoother and the well known median.
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    Adjoint Networks with Inverting and Noninverting Current Conveyors
    (Společnost pro radioelektronické inženýrství, 2000-04) Vrba, K.; Dostal, T.; Cajka, J.
    Four types of second-generation current conveyors are shown. The realisation of the above conveyors using differential voltage current conveyors (VDCC) is presented. Two examples illustrate the building of adjoint networks containing second-generation current conveyors.
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    Empirical Models for Indoor Propagation in CTU Prague Building
    (Společnost pro radioelektronické inženýrství, 2000-04) Pechač, Pavel; Klepal, M.
    Indoor propagation modelling is demanded for the design and maintenance of indoor wireless services. Empirical modelling seems to be the most efficient approach. Even so there are many studies dealing with empirical models for indoor propagation, the results can be hardly used for local buildings without modifications. There are several specific architecture styles and used materials. The indoor propagation measurement campaigns in the frequency range of 900 MHz were done in two typical multi-storey university buildings in Prague. Based on the measurement results, the easy-to-use empirical propagation prediction were derived for both of the buildings with satisfactorily accuracy. variations of the models were studied. The models are being implemented into a CAD software tool for complex design of indoor cellular systems. The project continues using a similar approach for other frequency bands. In the same time, other novel ways of semi-empirical modeling of indoor propagation are investigated.