In this paper, a generalized floating emulator block is proposed using grounded elements. The proposed emulator is a universal emulator that is used to realize any floating elements such as fractional-order element (FOE) and fractional-order memelements (FOME). Different implementations for the introduced emulator are presented using different active blocks and generalized impedances. The fractional-order parameters add an extra degree of controllability on the hysteresis loop (HL) and the location of the pinched point, which will be investigated. Circuit simulations for the proposed circuits

The mathematical formulae of six topologies of fractional-order Colpitts oscillator are introduced in this paper. Half of these topologies are based on MOS transistor, and the other half is based on BJT transistor. The design procedure for all of these topologies is proposed and summarized for each one. Stability analysis is very crucial in oscillators’ design, as oscillators should have its poles on the imaginary axis to obtain a sustained oscillation. Hence, determining the factors that control the oscillator’s stability is very important. An intensive study of the stability of Colpitts

In this paper, we propose a new hyperchaotic temperature fluctuations model and describe its modelling in detail. We study the characteristics of the new hyperchaotic temperature fluctuations model such as its phase portraits, rest points, symmetry, invariance, Lyapunov characteristic exponents, bifurcation analysis, etc. In fact, it is shown that the new temperature fluctuations model has a self-excited, two-scroll, hyperchaotic attractor with complex properties. The circuit simulation of the new temperature fluctuations model is carried out in MultiSim to verify the feasibility of the

This paper introduces a study for the effect of using different floating-point representations on the chaotic system's behaviour. Also, it offers a comparison between the attractors at three different orders, (integer, fractional, and mixed-order). This comparison shows the minimum number of bits needed for all parameters to simulate the chaotic attractor in each case. Numerical simulations using Matlab are presented for all discussed chaotic systems. This study opens the door to implement chaotic systems and different applications digitally with low hardware area. The FPGA hardware

This paper proposes voltage- and current-controlled universal memelements emulators. They are employed to realize the floating and grounded fractional-order memelements. The proposed emulators are implemented using different active blocks such as the second-generation current conveyor (CCII), Differential input double output transconductance amplifier (DOTA + ), balanced output CCII, and Differential voltage current conveyor (DVCC) with analog voltage multiplier. One of the main characteristics of the memristive elements is hysteresis loop behaviour with one pinched point, and the higher-order

This paper presents a new hybrid chaos synchronization scheme, which assures the co-existence of the full-state hybrid function projective synchronization (FSHFPS) and the inverse full-state hybrid function projective synchronization (IFSHFPS) between wide classes of three-dimensional master systems and four-dimensional slave systems. In order to show the capability of co-existence approach, numerical example is reported, which illustrates the co-existence of FSHFPS and IFSHFPS between 3D chaotic system and 4D hyperchaotic system in different dimensions. © Springer Nature Switzerland AG 2019.

In this paper a simple private communications system is proposed based on Chua's chaotic system. The system mainly consists of two synchronized chaotic circuits, the system encodes values to a message function according to the state of synchronization between the two circuits. Numerical simulations were carried out to prove the validity of the system, and spice simulations were carried out on the proposed physical system. © 2019 IEEE.

This work presents a novel fractional H8 robust indirect adaptive fuzzy logic control strategy based on the variable structure control theory design (FRAFC-VSC) to synchronize two fractional-order chaotic systems. The contribution of this work is the use of an adaptive fractional order PI-regulator and a saturation function to eliminate the chattering phenomena in the control and surface signals. Stability analysis is performed for the proposed method with an acceptable synchronization error level based on Lyapunov stability criterion. The synchronization of two different fractional order

This paper addresses the problem of generalized synchronization (GS) between fractional order chaotic systems. In this paper, we propose a new control strategy for a complex generalized synchronization (GS) scheme dedicated to non-identical fractional-order chaotic systems characterized by different dimensions. The proposed control parameters are nonlinear in nature. In order to ensure that the proposed scheme converge towards zero, we establish the asymptotic stability of the zero solution to the error system by means of the stability of linear fractional-order systems. In order to assess the

A differentiator-based set up is proposed as an alternative solution to measure bio-impedance. The method is modifying the differentiator circuit, replacing the capacitor with the Cole-impedance model representing the biological (fruit) sample. The proposed differentiator gain response (with the embedded fruit) is experimentally recorded. The experimental data’s post-processing is performed using meta-heuristic optimization techniques to extract the Cole-impedance model unknown parameters by solving a group of nonlinear equations. Three meta-heuristic optimization algorithms are used: the moth