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Hyperchaos and adaptive control of a novel hyperchaotic system with two quadratic nonlinearities

Liu-Su-Liu chaotic system (2007) is one of the classical 3-D chaotic systems in the literature. By introducing a feedback control to the Liu-Su-Liu chaotic system,we obtain a novel hyperchaotic system in this work, which has two quadratic nonlinearities. The phase portraits of the novel hyperchaotic system are displayed and the qualitative properties of the novel hyperchaotic system are discussed. We show that the novel hyperchaotic system has a unique equilibrium point at the origin, which is unstable. The Lyapunov exponents of the novel 4-D hyperchaotic system are obtained as L1 = 1.1097, L2

Circuit Theory and Applications

A new method to synchronize fractional chaotic systems with different dimensions

By using two scaling function matrices, the synchronization problem of different dimensional fractional order chaotic systems in different dimensions is developed in this chapter. The controller is designed to assure that the synchronization of two different dimensional fractional order chaotic systems is achieved using the Lyapunov direct method.Numerical examples and computer simulations are used to validate numerically the proposed synchronization schemes. © Springer International Publishing AG 2017. All rights reserved.

Circuit Theory and Applications

On new fractional inverse matrix projective synchronization schemes

In this study, the problem of inverse matrix projective synchronization (IMPS) between different dimensional fractional order chaotic systems is investigated. Based on fractional order Lyapunov approach and stability theory of fractional order linear systems, new complex schemes are proposed to achieve inverse matrix projective synchronization (IMPS) between n-dimension and m-dimension fractional order chaotic systems. To validate the theoretical results and to verify the effectiveness of the proposed schemes, numerical applications and computer simulations are used. © Springer International

Circuit Theory and Applications

Energy Harvesting Schemes for Wearable Devices

For the specifications of Wireless Body Area Networks (WBANs), eHealth systems, and wearable devices, batteries are not desirable. They maximize the sensor nodes’ size and need to be replaced every few years through human interference. Energy harvesting is now being studied as the primary source of electricity for wearable devices. Several initiatives have succeeded in using energy harvesting to operate the wearable devices’ electronic components. However, to rely primarily on energy harvesting in wearable devices, some obstacles need to be addressed. This work surveys the development of

Circuit Theory and Applications

Fractional-order Fitzhugh-Nagumo and Izhikevich neuron models

This paper studies the famous Fitzhugh-Nagumo and Izhikevich neuron models in the fractional-order domain. Generalization of the integer models into the fractional-order domain providing a wider scope understanding of the neuron systems. The fractional Fitzhugh-Nagumo circuit model and the state space equations are introduced. Different fractional orders are studied as an example. Numerical solutions of the systems are given using non-standard finite difference scheme together with Grunwald-Letnikov discretization technique which is computationally efficient and accurate. The two models are

Circuit Theory and Applications

Parameter identification of fractional-order chaotic systems using different Meta-heuristic Optimization Algorithms

Fractional-order chaotic systems (FOCS) parameter identification is an essential issue in chaos control and synchronization process. In this paper, different recent Meta-heuristic Optimization Algorithms are used to estimate the parameters and orders of three FOCS. The investigated systems are Arneodo, Borah rotational attractor and Chen double- and four-wing systems. The employed algorithms are the Salp Swarm Algorithm, Whale Optimization Algorithm, Moth-Flame Optimizer, Grey Wolf Optimizer and the Flower Pollination Algorithm (FPA). The proposed algorithms are applied on several objective

Circuit Theory and Applications

Rates and Effects of Local Minima on Fractional-Order Circuit Model Parameters Extracted from Supercapacitor Discharging Using Least Squares Optimization

Optimization routines are widely used to numerically determine a set of model parameters that best fit collected experimental data. One recent application of these methods is to extract the fractional-order circuit model parameters that accurately characterize the transient behavior of discharging supercapacitors. However, the variability that these methods introduce to the extracted model parameters must be understood to determine if changes in model parameters are artifacts of the optimization routine or are representative of physical changes in the device under study. In this work, the

Circuit Theory and Applications

Two-port two impedances fractional order oscillators

This paper presents a study for general fractional order oscillator based on two port network where two topologies of oscillator structure with two impedances are discussed. The two impedances are chosen to be fractional elements which give four combinations for each topology. The general oscillation frequency, condition and the phase difference between the two oscillatory outputs are deduced in terms of the transmission matrix parameter of a general two port network. As a case study: two different networks are presented which are op-amp based circuit and non-ideal gyrator circuit. The

Circuit Theory and Applications

Conical and cylindrical metallic nanoparticles design for plasmonic photovoltaics enhancement

Plasmonic Photovoltaics are considered as a promising candidate for enhancing the optical absorption by embedding metallic nanoparticles that confine the incident light in the cell. This results in thin-film PVs with improved efficiency. In this paper, the effects of embedding both conical and cylindrical metal nanoparticles in plasmonic PVs are investigated. The extinction cross sections for these designs are calculated. The improvement of the optical absorption of the solar cell due to these nanoparticles is proved and compared. Finally, the effects of the design parameters of these

Circuit Theory and Applications

Speech encryption using generalized modified chaotic logistic and tent maps

This paper presents a speech encryption application, which utilizes several proposed generalized modified discrete chaotic maps based on the logistic and tent maps for pseudo-random number generation. The generalization scales the output range and the key space. The modification controls the bounds on the output range through a parameter such that chaotic output exists for almost all values of the parameter. Consequently, the modified maps do not suffer from the inherited problems of conventional chaotic generators such as islands of stability and drifting from chaos due to dynamical

Circuit Theory and Applications