1,721,093 research outputs found
FORECASTING OF HYPERCHAOTIC SYSTEM STATE VARIABLES USING ONE OBSERVABLE
No full textIn the last years, growing attention has been paid to the reconstruction of chaotic
attractors from one or more observables. In this paper a Multi Layer Perceptron with a
tapped line as input, is used to forecast the hypercaotic Rössler system state variables
starting from measurements of one observable. Results show satisfactory prediction
performance if a sufficient number of taps is used. Moreover, a sensitivity analysis has
been performed to evaluate the predictiveness of the different delayed input in the neural
network model
Effect of a particular coupling on the dynamic behavior of nonlinear systems
No full textIn this paper, the dynamics of particular nonlinear dynamic systems of order six, characterized by two positive Lyapunov exponents, is analyzed. Transformation techniques are applied to the study of these systems; in particular, the analysis of the transverse and tangent systems showed that they are equivalent to two uncoupled identical chaotic systems of order three. Examples of polynomial and piecewise linear systems are proposed. Both numerical simulation and circuit implementation have been performed. Moreover, a systematic method to project these systems is presented
An algebraic observability approach to chaos synchronisation by sliding differentiators
No full textIn this paper, an observability approach to the synchronization of chaotic and hyperchaotic systems is presented. The proposed method allows the reconstruction of a chaotic attractor from a scalar observable and its derivatives. The method is based on the concept of algebraic observability; hence, it is directly applicable to all chaotic algebraic systems. Moreover, it is shown that a sliding differentiator, derived by a second-order suboptimal control algorithm, can be used to reconstruct the time derivatives of the observable. This makes it possible to estimate the system state, i.e., chaos synchronization, in a finite time
Algebraic Approach to Ambiguity Groups Determination in Non Linear Analog Circuits
No full textIn this paper, a symbolic procedure for ambiguity-group determination, based on the a priori identifiability concept, is proposed. The method starts from the analysis of the occurrence of circuit parameters in the coefficients of the input/output relationship in order to select the potential canonical ambiguity groups. This first step allows one to strongly reduce the problem complexity. In a second step, the obtained nonlinear system that imposes the ambiguity conditions is solved, resorting to Gro??bner bases theory. Both of these steps are completely symbolic, thus avoiding round-off errors. Furthermore, the method can be applied to both linear and nonlinear circuits. An alternative approach is also proposed, which extends to nonlinear circuits a method presented in the literature, which can be directly applied only to linear circuits. The methods are illustrated by means of benchmarks regarding well-known linear and nonlinear circuits
A neural network approach for the prediction of cross talk in non uniform multiconductor transmission lines
No full textHyperchaotic behaviour of two bi-directionally coupled Chua's circuits
Full text linkIn this paper, a non-linear bi-directional coupling of two Chua's circuits is presented. The coupling is obtained by using polynomial functions that are symmetric with respect to the state variables of the two Chua's circuits. Both a transverse and a tangent system are studied to ensure a global validity of the results in the state space. First, it is shown that the transverse system is an autonomous Chua's circuit, which directly allows the evaluation of the conditions on its chaotic behaviour, i.e. the absence of synchronization between the coupled circuits. Moreover, it is demonstrated that the tangent system is also a Chua's circuit, forced by the transverse system; therefore, its dynamics is ruled by a time-dependent equation. Thus, the calculus of conditional Lyapunov exponents is necessary in order to exclude antisynchronization along the tangent manifold. The properties of the transverse and tangent systems simplify the study of the coupled Chua's circuits and the determination of the conditions on their hyperchaotic behaviour. In particular, it is shown that hyperchaotic behaviour occurs for proper values of the coupling strength between the two Chua's circuits. Finally, numerical examples are given and discussed
Non Linear Circuits Ambiguity Groups Determination via Input-Output relationship Analysis
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