1,721,061 research outputs found
The dynamics of coupled oscillators
No full textWe consider a population of coupled oscillators characterized by a limit cycle. The analysis is developed by means of analogue simulation that allows us to obtain a wide overview of the dynamics as a function of the intensity of coupling. We Found behaviours such as synchronisation, transient phase locking and cluster formation. The global quantity corresponding at the sum of the amplitudes was considered as an indicator of the dynamics. An interesting property of this quantity is the presence of a maximum of fluctuations corresponding to a special intensity of the coupling
STOCHASTIC RESONANCE IN PERIODIC POTENTIALS
No full textWe have studied the motion of a particle in a periodic potential plus a bias, driven by a noise and a coherent forcing. The response (power spectrum) of the particle at the driving forcing frequency is considered for different values of the noise intensity and of the bias. It is shown via direct simulation that the response displays the phenomenon of stochastic resonance, although the phenomenology is somehow different from the one observed in the standard bistable system
MODIFYING THE ONSET OF HOMOCLINIC CHAOS - APPLICATION TO A BISTABLE POTENTIAL
No full textWe analyze, by means of the Melnikov method, the possibility of modifying the threshold of homoclinic chaos in general one-dimensional problems, by introducing small periodic resonant modulations. We indicate in particular a prescription in order to increase the threshold (i.e., to prevent chaos), and consider then its application to the bistable Duffing-Holmes potential. All results are confirmed both by numerical and by analog simulations, showing that small modulations can in fact sensibly influence the onset of chaos
Controlling chaos with parametric perturbations
No full textWe consider the effects of parametric perturbation on the onset of chaos in different dynamical systems. Favoring or suppression of chaos was observed depending on the phase or the frequency of the periodic perturbation. A lowering of the threshold of chaos was observed in an electronic device simulating a Josephson-Junction model and the suppression of chaos was obtained in a bistable mechanical device. We showed that in case of spatial instability in a sample of liquid crystal, the action of the parametric perturbation is to modify the velocity and the onset of the defects. Considering that the emergence of defects precedes the threshold of spatio-temporal chaos, we infer that parametric perturbation can modify the threshold of chaos in this spatial dynamical system
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