Prof. Ahmed Radwan

This paper introduces a study of fractional-order PID (FOPID) controller applied to a DC motor. The idea is to control the motor speed using the FOPID and compare it with the conventional PID controller. Two approximation techniques are employed to realize the FOPID, which are Matsuda and Oustaloup, each with order four. Different responses are depicted for various fractional orders. A specific

This paper studies banana fruit ripping using the Cole-impedance model fitted over the measured bio-impedance data by monitoring the changes in the model parameters during the different ripping stages. A set of twenty bananas are tested for 84 hours, and impedance measurements are done every 12 hours using an SP150 electrochemical station. The changes in model parameters are related to the

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

This paper introduces an approximate solution for Liouville-Caputo variable order fractional differential equations with order 0

This paper introduces two new versions for memristor-based center pulse-width modulator (PWM) circuits. The proposed circuits use only one comparator which reduces the circuit complexity and power dissipation compared to a former work. The first design is based on two memristors and two resistors while the second design is based on four memristors. Theoretical analysis is provided, and the

This paper introduces a method for extracting the Cole-impedance model parameters using a meta-heuristic optimization technique. The method is based on a single proposed resistor controlled oscillator (SRCO) where the unknown bio-impedance is embedded. At two different oscillation frequencies, the start-up oscillation condition is recorded. Then the corresponding nonlinear equations are solved

Approximations of the fractional-order differentiator and integrator operators s±r are proposed in this work. These approximations target the realization of these operators using standard active filter transfer functions. Hence, circuit implementations in integrated circuit form or in discrete component form are significantly facilitated. Complementary metal-oxide-semiconductor (CMOS) realizations

Solar energy turns into a promising supply of electricity, so structures of Photo-voltaic (PV) regularly use a maximum power point tracking (MPPT) way to deliver the highest probable power to the load continuously. This paper presents the methodology of PI controller tuning of PV employing Particle Swarm Optimization (PSO). The aim is to obtain the maximum power and maintain its value using the PI

Bio-impedance measurement has been used as an indicator for specific physical and chemical changes in food products, fruits and vegetables, cancer detection and other applications. In this paper, a portable wireless bio-impedance measurement embedded system, based on the AD5933 chip, is introduced. The system is calibrated using a parallel RC network and the industry standard electrochemical