Prof. Ahmed Radwan

We show that the four parameters of a single-dispersion Cole-Cole bio-impedance model can be extracted from an one time-domain measurement with a fixed frequency. In particular, a periodic triangle waveform current excitation signal is injected into the biological sample under study while measuring the voltage developed across this sample in a galvanostatic measurement setup. The voltage response

This paper proposes a general prototype fractional order filter based on a two-port network concept with four external impedances. Three induced classifications from the general prototype are extracted with one, two and three external impedances, achieving ten possible generalized topologies. The external impedances are fractional-order elements and resistors. There are forty-six filters divided

This paper proposes the realization of grounded and floating fractional order mem-elements (FOMEs) based on two- and three-port mutators, respectively. Three different topologies based on two-port mutators are implemented using the four members of the second-generation current conveyor (CCII) family which is useful to achieve several realizations for the same circuit. The Fractional Order Mem

Due to the non-linear relation between current and voltage of the PV modules, DC/DC power electronic converters are used to adapt this non-linearity. Controllers are used to control the DC/DC converters in order that, they can take actions against changes in irradiance input levels, temperature input levels and load values. In this study, a standalone PV system that feeds a DC load is simulated

Electrochemical Impedance Spectroscopy (EIS) has been used as a technique for the assessment of food attributes. This paper discusses the effect of injuries caused by heating and freezing treatments to plant's bioimpedance. Unlike other studies to these kinds of injuries, experiments are carried out on the whole fruit using non-invasive electrodes keeping the plant tissues unharmed. Moreover, one

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

Precise parameter extraction of the bio-impedance models from the measured data is an important factor to evaluate the physiological changes of plant tissues. Traditional techniques employed in the literature for this problem are not robust which reflects on their accuracy. In this paper, the Flower Pollination Algorithm (FPA), the Grey Wolf Optimizer (GWO) and ten of their chaotic variants are

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 generalizes the Izhikevich neuron model in the fractional-order domain for better modeling of neuron dynamics. Accurate and computationally efficient numerical techniques such as non-standard finite difference (NSFD) scheme is used to solve the neuron system in the fractional-order domain for different cases. Neuron synchronization plays an important role in the process of information