In this work, we demonstrate the possibility of performing two-dimensional rotation on a chaotic system. This enables the rotation of its attractor in space without changing its chaotic dynamics. In particular, the rotated system preserves the same eigenvalues at all equilibrium points and its largest Lyapunov exponent remains unchanged. Two chaotic systems, one of which is the classical Lorenz

The current methods used for estimating the electrical parameters of organic solar cells (OSC) from time-domain measurements are based on integer-order impedance models. Meanwhile, in the frequency-domain, the adopted circuit models usually contain a constant phase element which is known to capture effectively the fractional-order dispersive behavior of these devices. Therefore, inconsistency

Novel fractional-order capacitor and inductor em-ulators are presented in this work, which offer fully electronic tunability of their characteristics and, simultaneously, reduced circuit complexity compared to those already introduced in the literature. This has been achieved through the utilization of the log-domain filtering for implementing the approximation of the required fractional-order

Memristor characteristics such as nonlinear dynamics, state retention and accumulation are useful for many applications. FPGA implementation of memristor-based systems and algorithms provides fast development and verification platform. In this work, we first propose a versatile digital memristor emulator that exhibits either continuous or discrete behaviors, similar to valence change memories (VCM

This paper proposes two generalized topologies of fractional order inverse filters (FOIF). All possible realizations of each topology are investigated using the second generation current conveyor (CCII) family. Inverse fractional highpass (IFHPF), inverse fractional bandpass (IFBPF), and inverse fractional lowpass (IFLPF) filters are realized using the same topology based on the generalized

In this paper, an enhanced version of the improved Howland circuit is proposed. An improvement in output impedance to a maximum factor of two is obtained. The theoretical derivation is presented, including analysis from a two-port network perspective, and both simulation and experimental results using a general purpose opamp confirm the expected result. © 2019 John Wiley & Sons, Ltd.

This paper introduces an FPGA design methodology of a sample and bit permutation speech encryption system. Pipelining method is used to build the proposed system, which can have different number of permutation levels. The security of the system is evaluated using entropy, Mean Squared Error (MSE) and correlation coefficients comparing the different permutation levels. The results demonstrate the

Supercapacitors are crucial elements in advanced industrial electronic systems particularly when supplied from renewable energy sources. Here, we derive expressions for the current, power, and stored energy in a supercapacitor excited with a step voltage signal. Although, it is not common practice to charge supercapacitors using a step voltage, these devices are sometimes used in switching-type

This paper proposes generalized controllable strange attractors through dynamic rotation of fractional-order chaotic systems. Dynamic rotation angle enables the generation of multi-scroll and multi-wing attractors from single and double-scroll ones. The rotating systems are integrated with a generalized dynamic switched synchronization scheme. Dynamic control switches determine whether each system

This paper proposes a generalized modified chaotic transition map with three independent parameters. A hardware speech encryption scheme utilizing this map along with a bit permutation network is presented. While the transition map’s generalization introduces additional parameters, the modification enhances its chaotic properties and overcomes the finite range of the control parameter and