TY  - JOUR
A1  - Nikolov, S.
A1  - Clodong, Sébastien
T1  - Occurrence of regular, chaotic and hyperchaotic behavior in a family of modified Rossler hyperchaotic systems
N2  - In this paper, we demonstrate that it is possible to control the hyperchaos into the Rossler hyperchaotic system (RHS) by linear feedback of own signals. After introducing of the parameter "b" in the z-equation (b --> b + b(1)x(t) + b(2)y(t) + b(3)z(t) + b(4)w(t)), we study how the global dynamics can be altered in a desired direction (b(n) are considered as free parameters). We make a detailed bifurcation investigation of the modified Rossler hyperchaotic systems by varying the parameters b,. Finally, we calculate the Lyapunov exponents and the information dimension, where the regular, chaotic and hyperchaotic motion of modified RHS exist. (C) 2004 Published by Elsevier Ltd
Y1  - 2004
SN  - 0960-0779
ER  - 
TY  - JOUR
A1  - Blasius, Bernd
A1  - Clodong, Sébastien
T1  - Chaos in a periodically forced chemostat with algal mortality
N2  - We study the possibility of chaotic dynamics in the externally driven Droop model. This model describes a phytoplankton population in a chemostat under periodic supply of nutrients. Previously it has been proven under very general assumptions that such systems are not able to exhibit chaotic dynamics. Here we show that the simple introduction of algal mortality may lead to chaotic oscillations of algal density in the forced chemostat. Our numerical simulations show that the existence of chaos is intimately related to plankton overshooting in the unforced model. We provide a simple measure, based on stability analysis, for estimating the amount of overshooting. These findings are not restricted to the Droop model but hold also for other chemostat models with mortality. Our results suggest periodically driven chemostats as a simple model system for the experimental verification of chaos in ecology.
Y1  - 2004
ER  -