Wyniki 1-5 spośród 5 dla zapytania: authorDesc:"Lubomír BRANČÍK"

Procedures for matrix exponential function derivative in Matlab

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The paper deals with a few approaches how to determine a derivative of the matrix exponential function in the Matlab language. A usefulness for such the computation appears in many branches of the electrical engineering when various simulation tasks are solved. A Taylor series expansion, an augmented matrix utilization, an eigenvalues decomposition, a Laplace transform approach, a convolution in[...]

Modified technique of FFT-based numerical inversion of Laplace transforms with applications

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The paper presents a modified technique of numerical inversion of Laplace transforms based on FFT and quotient-difference algorithms and its Matlab implementation. The method enables to process general transforms of more complex variables and can therefore serve as a basis for inversion of multidimensional Laplace transforms. An application of the method is illustrated by getting matrix exponent[...]

Utilization of NILTs in Simulation of Nonlinear Systems Described by Volterra Series

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The techniques of numerical inverse Laplace transforms (NILTs) are applied to get the time-domain responses of some classes of nonlinear systems. It is enabled by expanding the system response into a Volterra series formulated in multidimensional Laplace domains. For a given system the Volterra kernel transforms are found, and the response Laplace transforms inverted numerically. By this way the use of an association of variables technique is avoided to save CPU time. The NILTs based on FFT/IFFT and q-d algorithms are modified for this purpose. Streszczenie. W pracy pokazano metodę wyznaczania odpowiedzi czasowej układów nieliniowych w oparciu o technikę numeryczną obliczania odwrotnej transformaty Laplace’a. Jest to możliwe przez rozwinięcie odpowiedzi w szereg Volterry wyrażon[...]

Application of Stochastic Differential Equations in Second-Order Electrical Circuits Analysis

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The paper deals with an unconventional approach to the analysis of electrical circuits with randomly varying parameters based on stochastic differential equations (SDE). A response of the electrical circuit is computed in the form of a sample mean with a particular confidence interval to provide credible estimate of the result. The method is applied to get voltage and current responses of the second-order RLGC network excited from a voltage source with a noise term. The results are compared with the classical deterministic state-variable approach. Streszczenie. W artykule przedstawiono niekonwencjonalna metodę analizy obwodu elektrycznego o przypadkowo zmienianych parametrach. Metoda bazuje na stochastycznych równani ach różnicowych SDE. Metodę sprawdzono na przykładzie określania napięcia i prądu w sieci drugiego rzędu RLGC zasilanej napięciem z szumami. (Zastosowanie stochastycznych równań różnicowych w obwodach elektrycznych drugiego rzędu) Keywords: stochastic differential equation, Itô formula, second-order electrical circuit, state variable. Słowa kluczowe: równania stochastyczne, obwody elektryczne drugiego rzędu, analiza obwodów Introduction The study of stochastic phenomena has been stimulated by the need of taking into account random effects while modelling physical systems. An interesting approach of that is to replace parameters in the deterministic model by random processes. In this context the stochastic differential equations (SDE) can be utilized to characterize a response of such a model [1-3]. The most attention has still been paid to the first-order RL or RC circuits, see e.g. [4-7], where main SDE concepts and suitable numerical techniques were widely studied and verified. From practical point of view, however, just secondorder RLC and RLGC networks are of major importance as they may often serve as building blocks of more complex physical models. Namely, our intention in the paper is to get ready a concept for [...]

Sinusoidal oscillator based on Adjustable Current Amplifier and Diamond Transistors with Buffers

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Easy tunable oscillator based on current amplifier and diamond transistors with buffers is presented in the paper. Electronic adjusting of oscillation frequency is easy possible due to controllable current gain of used current amplifier. All capacitors of the oscillator are grounded. The characteristic equation, condition of the oscillation and parasitic influences of real active components are discussed. It is possible to verify the function of the circuit using commercially available devices what is strong advantage. The verification of functionality was provided by simulations and laboratory experiments. Streszczenie. Zaprezentowano łatwo strojony generator bazujący na wzmacniaczu prądu I tranzystorach diamentowych. Ustawianie wybranej częstotliwości jest łatwe dzięki kontrolowanemu wzmocnieniu prądu. Wszystkie kondensatory układu są uziemione. Przedyskutowano równanie charakterystyczne, warunki oscylacji i wpływy pasożytnicze. Przeprowadzono symulacje oraz testy laboratoryjne. (Generator sinusoidalny z nastawianym wzmacniaczem prądu i tranzystorami diamentowymi z buforem) Keywords: Electronic adjusting, sinusoidal oscillator, diamond transistor, controllable current amplifier. Słowa kluczowe: generator sinusoidalny, tranzystor diamentowy.. Introduction Today many of modern active functional blocks are available for application in analog signal processing. This fact is discussed in the paper [1] where the review of basic and novel active blocks is given. Some applications of these components have been given in the literature, for example differencing buffered transconductance amplifier (DBTA) [2], current follower transconductance amplifier (CFTA) [3] and others. An attention is now focused on the applications in current mode (CM) [4]. There are some modifications of known circuit components, for example the current conveyors (CC), the current feedback amplifiers (CFA) and the transconductors (OTA) which are called as DO-CCCII [5[...]

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