A power-law compensator scheme for achieving robust frequency compensation in control systems including plants with an uncertain pole, is introduced in this work. This is achieved through an appropriate selection of the compensator parameters, which guarantee that the Nyquist diagram of the open-loop system compensator-plant crosses a fixed point independent of the plant pole variations. The implementation of the fractional-order compensator is performed through the utilization of a curve-fitting-based technique and the derived rational integer-order transfer function is realized on a Field

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.

Multipliers are a major energy and delay contributor in modern compute-intensive applications due to their complex logic architecture. As such, designing multipliers with reduced energy and faster speed has remained a thoroughgoing challenge. This paper presents a novel, carry-free multiplier, which is suitable for a new-generation of energy-constrained applications. The multiplier circuit consists of an array of memristor-transistor cells that can be selected (i.e., turned ON or OFF) using a combination of DC bias voltages based on the operand values. When a cell is selected it contributes to

A novel procedure for the realization of a fractional-order PID loop-shaping controller, suitable for precision control of mechatronic systems, is introduced in this work. Exploiting appropriate tools, the controller function is approximated as a whole, leading to a simple form of integer-order approximation, when compared to the case where each intermediate part of the PID transfer function is approximated. This leads to a direct implementation, composed of conventional active and passive elements. Simulation and experimental results, derived from the OrCAD PSpice simulator and a Field

Tolerance variations of the design parameters of the photonic crystals due to fabrication processes have a strong effect on the performance of the photonic crystals and their operating wavelengths. In this work, the uncertainties of the design parameters of one-dimensional photonic crystals (1D-PCs) and their impacts on the PCs optical properties and the operating performance are investigated. The effects of these uncertainties for different tolerances are studied for both defect-free PCs and PCs with a defect air layer. The probability distribution function and the standard deviations of the

Red phosphorus and sulfurized polyacrylonitrile (RP-SPAN) composite has recently shown promising results as an anode material in lithium-ion battery applications. However, the stability analysis of its dynamic response has not been investigated yet. In this study we use the transfer function stability analysis, the Kramers-Kronig (KK) integral relations, and the differential capacity analysis to evaluate the cell's behavior in both frequency and time domains in terms of stationarity, stability, linearity, as well as dissipation and degradation with extended charge/discharge cycling. The

This paper introduces two methods for the numerical solution of distributed order linear fractional differential equations. The first method focuses on initial value problems (IVPs) and based on the αth Caputo fractional definition with the shifted Chebyshev operational matrix of fractional integration. By applying this method, the IVPs are converted into simple linear differential equations which can be easily handled. The other method focuses on boundary value problems (BVPs) based on Picard's method frame. This method is based on iterative formula contains an auxiliary parameter which

The fractional-order model of a phantom electroencephalographic system, at various distances between electrodes, is realized using appropriate decomposition of the rational transfer functions which approximate the highpass filters that describe its dynamics. The main offered benefits, in comparison to the corresponding straightforward implementations of the rational transfer functions, are the capability of monolithic implementation due the minimization of the maximum value of the required capacitances and, also, the reduced power consumption. The performance of the presented filter topologies

Interconnect design has recently become one of the important factors that affect the circuit delay and performance especially in the deep submicron technology. The modelling of interconnects is typically based on using Elmore definitions of the delay time and rise time. So, a general formula for Elmore delay time and rise time in the fractional order domain are presented in this work. It is found from the new formulas of the delay time and rise time that these timing values could be controlled or tuned by the fractional orders. Hence, the fractional order can compensate for the components

In this work, the Artificial Neural Networks (ANN) are used to model a chaotic system. A method based on the Non-dominated Sorting Genetic Algorithm II (NSGA-II) is used to determine the best parameters of a Multilayer Perceptron (MLP) artificial neural network. Using NSGA-II, the optimal connection weights between the input layer and the hidden layer are obtained. Using NSGA-II, the connection weights between the hidden layer and the output layer are also obtained. This ensures the necessary learning to the neural network. The optimized functions by NSGA-II are the number of neurons in the