2007/3
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Recent Submissions
- ItemBiquads Based on Single Negative Impedance Converter Implemented by Classical Current Conveyor(Společnost pro radioelektronické inženýrství, 2007-09) Dostal, Tomas; Axman, VladimirThe paper deals with continuous-time ARC biquadratic (second-order) filters based on the single classical three-port current conveyors, so called second generation CC II. A unique application of the CC II is discussed, when the terminals Y and Z are connected together. Using this way a negative impedance converter is obtained as a suitable building block in synthesis of several biquads, including notch filters.
- ItemNew Statistics for Texture Classification Based on Gabor Filters(Společnost pro radioelektronické inženýrství, 2007-09) Bandzi, Peter; Oravec, Milos; Pavlovicova, JarmilaThe paper introduces a new method of texture segmentation efficiency evaluation. One of the well known texture segmentation methods is based on Gabor filters because of their orientation and spatial frequency character. Several statistics are used to extract more information from results obtained by Gabor filtering. Big amount of input parameters causes a wide set of results which need to be evaluated. The evaluation method is based on the normal distributions Gaussian curves intersection assessment and provides a new point of view to the segmentation method selection.
- ItemAnalysis of Analog Neural Network Model with CMOS Multipliers(Společnost pro radioelektronické inženýrství, 2007-09) Docheva, Liliana; Bekiarski, Alexander; Dochev, IvoThe analog neural networks have some very useful advantages in comparison with digital neural network, but recent implementation of discrete elements gives not the possibility for realizing completely these advantages. The reason of this is the great variations of discrete semiconductors characteristics. The VLSI implementation of neural network algorithm is a new direction of analog neural network developments and applications. Analog design can be very difficult because of need to compensate the variations in manufacturing, in temperature, etc. It is necessary to study the characteristics and effectiveness of this implementation. In this article the parameter variation influence over analog neural network behavior has been investigated.
- ItemA Robust Chaos-Based True Random Number Generator Embedded in Reconfigurable Switched-Capacitor Hardware(Společnost pro radioelektronické inženýrství, 2007-09) Drutarovsky, Milos; Galajda, PavolThis paper presents a new chaos-based True Random Number Generator (TRNG) with a decreased voltage supply sensitivity. Contrary to the traditionally used sources of randomness it uses a well-defined deterministic switched-capacitor circuit that exhibits chaos. The whole design is embedded into a commercially available mixed-signal Cypress PSoC reconfigurable device without any external components. The proposed design is optimized for a reduction of influence of the supply voltage to the quality of the generated random bit stream. The influence of circuit non-idealities is significantly reduced by the proposed XOR corrector and optimized circuit topology. The ultimate output bit rate of the proposed TRNG is 60 kbit/s and the quality of generated bit-streams is confirmed by passing standard FIPS and correlation statistical tests performed in the full range of PSoC device supply voltages.
- ItemSoftware for CATV Design and Frequency Plan Optimization(Společnost pro radioelektronické inženýrství, 2007-09) Hala, OndrejThe paper deals with the structure of a software medium used for design and sub-optimization of frequency plan in CATV networks, their description and design method. The software performance is described and a simple design example of energy balance of a simplified CATV network is given. The software was created in programming environment called Delphi and local optimization was made in Matlab.