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Nikola Burić

Publications and source records attributed to Nikola Burić.

3 recordsLinked to original sources

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↗

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↗

Investigation of the bone tissue response to glass-ionomer microimplants in the canine maxillary alveolar ridge.

This paper reports the results of experimental use of glass-ionomer microimplants in the augmentation of the maxillary alveolar ridge in dogs. The study included ten adult mongrel dogs 5 years of age, weighing between 50 and 70 pounds (25-30 kg), divided into 2 groups of 5 dogs each. In both groups, the maxillary 4th premolar and 1st molar were removed after the elevation of a buccal mucoperiosteal flap. The alveolar bone adjacent to the extracted teeth was also removed. In the experimental group (5 dogs), Ionogran a glass-ionomer microimplants (GIMIs) (Ionogran particle size of 0.5-1.0 mm, IONOS Medizinische Produkte GmbH & Co. KG, D-8031 Seefeld, Gemany) were used for augmentation and were inserted in the created defects. The extraction sockets and bone defects were augmented with an average amount of 2 g of GIMIs. In the control group, the bone defects were left unfilled as a control for bone healing. Histological examination showed that the glass-ionomer microimplants were extremely osteoconductive and inert materials. Stimulation of growth of new bone tissue in contact with the glass-ionomer microimplants was evident. No inflammatory cells were detected on or adjacent to the GIMIs. In the control group, incomplete bone healing with fibrous scar tissue and inflammatory cells was noted. These results indicate that glass-ionomer microimplants represent highly osteoconductive and biocompatible materials for use in bone surgery.

Aluminum Silicates↗