September 1996, Volume 5, Number 3
M. Harakal, J. Chmurny
Image Generation by Octree
This paper deals with the generating of three-dimensional (3-D) images by octree and using the application of tesseral theory in image processing.
Restoration of Local Degradations in Audio Signals
The paper presents an algorithm for restoration of local degradations in audio signals. The theoretical foundations and basic suggestions of this algorithm were published in . A complete description of restoration process and some improvements are presented here.
K. Vlcek, J. Popelek
Analog Hardware Description Language and Its Relations to VHDL
Primary motivations for analogue hardware description language (VHDL-A) is to support the modelling of physical systems. The VHDL-A must therefore allow to model the physical conservation laws, such as the energy conservation law, which states that energy can neither be created nor destroyed, but it can only change its form.
Interference Fading Prediction on the Line-of-Sight Radio Links
The fading on the LOS links is an important factor influencing the reliability of the communication. In this paper predictions models for interference fading are described. Predictions are compared with measured data of the experiment of TESTCOM & CTU PRAGUE in the frequency 13 GHz.
Prediction of Rain and Water Vapour Attenuation at Frequencies 10-30 GHz
This contribution discusses the attenuation of microwaves in the atmosphere and applies the results to the conditions in the Czech Republic. The simple CCIR method predicting the rain attenuation is described and the relevant rain intensity as the only meteorological parameter required is presented on a map. Five methods of evaluation of the water vapour attenuation are discussed and compared . Included is also the computation of the zenith water vapour attenuation and its distribution based on the statistical evaluation of real four-year vertical profiles of important meteorological parameters from the Prague station.
A. Urbas, B. Galinski
Unbalanced Czarnul Resistive MOS Circuit in the Symmetrical MOSFET-C Filters
The analysis of influence of mismatches of the MOS transistor array on center frequency ω0 and Q-factor of the MOSFET-C filter poles is performed. As a useful parameter characterizing mismatches of transistors, the dispersion of the threshold voltage VT and transconductance K per unit area in the VLSI process is considered The optimal formula for the control gate voltages VG1, VG2 of MOS transistors, minimizing the absolute errors of ω0 , Q parameters is given.