Intrinsic noise induced resonance in presence of sub-threshold signal in Brusselator

In a system of non-linear chemical reactions called the Brusselator, we show that {\it intrinsic noise} can be regulated to drive it to exhibit resonance in the presence of a sub-threshold signal. The phenomena of periodic stochastic resonance and aperiodic stochastic resonance, hitherto studied mostly with extrinsic noise, is demonstrated here to occur with inherent systemic noise using exact stochastic simulation algorithm due to Gillespie. The role of intrinsic noise in a couple of other phenomena is also discussed.Comment: 7 pages, 5 figure

Emergence of the stochastic resonance in glow discharge plasma

stochastic resonance, glow discharge plasma, excitable medium, absolute mean differenceComment: St

Coexisting synchronous and asynchronous states in locally coupled array of oscillators by partial self-feedback control

We report the emergence of coexisting synchronous and asynchronous subpopulations of oscillators in one dimensional arrays of identical oscillators by applying a self-feedback control. When a self-feedback is applied to a subpopulation of the array, similar to chimera states, it splits into two/more sub-subpopulations coexisting in coherent and incoherent states for a range of self-feedback strength. By tuning the coupling between the nearest neighbors and the amount of self-feedback in the perturbed subpopulation, the size of the coherent and the incoherent sub-subpopulations in the array can be controlled, although the exact size of them is unpredictable. We present numerical evidence using the Landau-Stuart (LS) system and the Kuramoto-Sakaguchi (KS) phase model.Comment: 13 pages, 13 figures, accepted for publication in CHAOS (July 2017

Controlling turbulence in coupled map lattice systems using feedback techniques

We report the suppression of spatiotemporal chaos observed in coupled map lattices. Suppression is achieved using different feedback techniques, most of which are applicable to actual experimental situations. Results from application of feedback control to a single chaotic element (single map) are presented to demonstrate similarities in the dynamical response of a single system and an extended system under the influence of external feedback

Regulating dynamics through intermittent interactions

In this letter, we experimentally demonstrate an efficient scheme to regulate the behaviour of coupled nonlinear oscillators through dynamic control of their interaction. It is observed that introducing intermittency in the interaction term as a function of time or the system state, predictably alters the dynamics of the constituent oscillators. Choosing the nature of the interaction - attractive or repulsive, allows for either suppression of oscillations or stimulation of activity. Two parameters $\Delta$ and $\tau$, that reign the extent of interaction among subsystems are introduced. They serve as a harness to access the entire range of possible behaviours from fixed points to chaos. For fixed values of system parameters and coupling strength, changing $\Delta$ and $\tau$ offers fine control over the dynamics of coupled subsystems. We show this experimentally using coupled Chua's circuits and elucidate their behaviour for a range of coupling parameters through detailed numerical simulations.Comment: To be published in Physical Review

Birhythmicity induced by perturbing an oscillating electrochemical system

We describe the generation of new limit cycles in electrochemical systems under the influence of external periodic perturbations. For certain specific parameters of a nonharmonic forcing function, two coexisting periodic orbits can be generated from a single limit cycle observed in the unperturbed dynamics. This inception of birhythmicity (bistability) is observed in both simulations and actual experiments involving potentiostatic electrodissolution of copper in an acetate buffer

Vibration control of frame structure using multiple tuned mass dampers

Need for taller structure in construction and real estate industry is increasing all over the world. These structures are flexible and constructed as light as possible (as seismic load acts on a structure is a function of self-weight), which have low value of damping, makes them vulnerable to unwanted vibration. This vibration creates problem to serviceability requirement of the structure and also reduce structural integrity with possibilities of failure. Current trends use several techniques to reduce wind and earthquake induced structural vibration. Passive tuned mass damper (TMD) is widely used to control structural vibration under wind load but its effectiveness to reduce earthquake induced vibration is an emerging technique. Here a numerical study is proposed on the effectiveness of tuned mass damper to reduce translation structural vibration. Total three type of models, i.e., shear building with single TMD, 2D frame with single TMD and 2D frame with double TMD are considered. Total five numbers of loading conditions are considered named sinusoidal ground acceleration, EW component of 1940 El-Centro earthquake (PGA=0.2144g), compatible time history as per spectra of IS-1893 (Part -1):2002 for 5% damping at rocky soil (PGA=1.0g), Sakaria earthquake (PGA=1.238g), The Landers earthquake (1992) (PGA=1.029g) for time history analysis of considered model.The effectiveness of single TMD to reduce frame vibration is studied for variation of mass ratio of TMD to frame. Also the effect of double tuned mass damper on the frame response is studied for uniform, non uniform distribution of mass ratio and variation of damping ratio of damper.From the study it is found that effectiveness of TMD increases with increase in mass ratio. Use of double TMD is much more effective than single TMD of same mass ratio for vibration mitigation under earthquake as well as sinusoidal acceleration