Articles written in Pramana – Journal of Physics
Volume 89 Issue 6 December 2017 Article ID 0092 Research Article
In this paper we report a time-delayed chameleon-like chaotic system which can belong to different families of chaotic attractors depending on the choices of parameters. Such a characteristic of self-excited and hidden chaotic flows in a simple 3D system with time delay has not been reported earlier. Dynamic analysis of the proposed time-delayed systems are analysed in time-delay space and parameter space. A novel adaptive modified functional projective lag synchronization algorithm is derived for synchronizing identical time-delayed chameleon systems with uncertain parameters. The proposed time-delayed systems and the synchronization algorithm with controllers and parameter estimates are then implemented in FPGA using hardware–software co-simulation and the results are presented.
Volume 90 Issue 3 March 2018 Article ID 0031 Research Article
In this article, a simple autonomous transiently chaotic flow with cubic nonlinearities is proposed. This system represents some unusual features such as having a surface of equilibria. We shall describe some dynamical properties and behaviours of this system in terms of eigenvalue structures, bifurcation diagrams, time series, and phase portraits. Various behaviours of this system such as periodic and transiently chaotic dynamics can be shown by setting special parameters in proper values. Our system belongs to a newly introduced category of transiently chaotic systems: systems with hidden attractors. Transiently chaotic behaviour of our proposed system has beenimplemented and tested by the OrCAD-PSpise software. We have found a proper qualitative similarity between circuit and simulation results.
Volume 90 Issue 4 April 2018 Article ID 0052 Research Article
The literature on chaos has highlighted several chaotic systems with special features. In this work, a novel chaotic jerk system with non-hyperbolic equilibrium is proposed. The dynamics of this new system is revealed through equilibrium analysis, phase portrait, bifurcation diagram and Lyapunov exponents. In addition, we investigate the time-delay effects on the proposed system. Realisation of such a system is presented to verify its feasibility.
Volume 90 Issue 6 June 2018 Article ID 0070 Research Article
Nowadays, designing chaotic systems with hidden attractor is one of the most interesting topics in nonlinear dynamics and chaos. In this paper, a new 4D chaotic system is proposed. This new chaotic system has no equilibria, and so it belongs to the category of systems with hidden attractors. Dynamical features of this systemare investigated with the help of its state-space portraits, bifurcation diagram, Lyapunov exponents diagram, and basin of attraction. Also a hardware realisation of this system is proposed by using field programmable gate arrays(FPGA). In addition, an electronic circuit design for the chaotic system is introduced.
Volume 94 All articles Published: 5 April 2020 Article ID 0062 Research Article
A memristive chaotic system of rotational symmetry is constructed and analysed. The dynamical behaviour of the system is demonstrated by phase trajectories, Lyapunov exponents and bifurcation diagrams. Coexisting attractors are observed and a simple approach for amplitude control is proposed according to the specific structure. It shows that this symmetric memristive system has partial amplitude control when a control function is introduced. The corresponding circuit implementation is given by generating a symmetric pair of chaotic attractors. Circuit results agree well with the theoretical analysis and numerical simulation.
Volume 94, 2020
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