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Biomedical subjects

Dragana Todorović

Publications and source records attributed to Dragana Todorović.

2 recordsLinked to original sources
PubMed2003

Synchronization of hyperchaotic systems with delayed bidirectional coupling.

Synchronization of three bidirectionally coupled hyperchaotic systems is studied, using the Ikeda model as the hyperchaotic unit. The whole system is given by three delay-differential equations with two distinct time lags. Sufficient condition for the global stability of the manifold of exact synchronization is found analytically. Local stability of the synchronization manifold is studied by numerical computation of the transverse Lyapunov exponent and statistical properties of the orbits.

Journal Article↗
PubMed2003

Dynamics of FitzHugh-Nagumo excitable systems with delayed coupling.

Small lattices of N nearest-neighbor coupled excitable FitzHugh-Nagumo systems, with time-delayed coupling are studied and compared with systems of FitzHugh-Nagumo oscillators with the same delayed coupling. Bifurcations of equilibria in an N=2 case are studied analytically, and it is then numerically confirmed that the same bifurcations are relevant for the dynamics in the case N>2. Bifurcations found include inverse and direct Hopf and fold limit cycle bifurcations. Typical dynamics for different small time lags and coupling intensities could be excitable with a single globally stable equilibrium, asymptotic oscillatory with symmetric limit cycle, bistable with stable equilibrium and a symmetric limit cycle, and again coherent oscillatory but nonsymmetric and phase shifted. For an intermediate range of time lags, inverse sub-critical Hopf and fold limit cycle bifurcations lead to the phenomenon of oscillator death. The phenomenon does not occur in the case of FitzHugh-Nagumo oscillators with the same type of coupling.

Journal Article↗