Analysis of polarization dynamics by singularity decomposition method

Model Predictive Control of Fractional Order Systems

This paper provides the model predictive control (MPC) of fractional order systems. The direct method will be used as internal model to predict the future dynamic behavior of the process, which is used to achieve the control law. This method is based on the Grünwald-Letnikov's definition that consists of replacing the noninteger derivation operator of the adopted system representation by a discrete approximation. The performances and the efficiency of this approach are illustrated with practical results on a thermal system and compared to the MPC based on the integer ARX model.

Frequency-domain reconstruction of signals in electrical bioimpedance spectroscopy

The use of an amplitude/phase retrieval algorithm in electrical bioimpedance spectroscopy (EIS) that allows a new technique to reconstruct the impedance spectrum in the frequency-domain is reported. To the authors' knowledge this is the first time the proposed algorithm has been used to calculate the modulus or phase of a bioimpedance in EIS from one of these two experimentally obtained parameters. The algorithmic technique is demonstrated in EIS, when wide-bandwidth amplifiers,phase-detectors, and high speed converters determine spectra over frequencies up to 500 kHz at isolated points in the frequency interval. Simulated data from bioimpedance models (Cole and 2R1C circuit impedance functions) and experimental data from a known electrical impedance are used to show the applicability and limitations of the technique with a phase retrieval and a modulus retrieval algorithm.Results comparing this technique with the Kramers-Kronig technique that retrieves the imaginary part of an impedance from its real part are also discussed.

Linear and nonlinear electrode polarization and biological materials

Electrode polarization is a major nuisance while determining dielectric properties of cell and particle suspensions and tissues, particularly at low frequencies. Understanding of these interfacial phenomena and appropriate modelling are essential in order to correct for its distortion of the dielectric properties of the sample of interest. I survey the following topics, concentrating on contributions from our laboratory: Linear properties of electrode polarization and relevant models. Effects of electrode polarization on sample impedance. Effects of sample on polarization impedance. Techniques of correction. Extension of linear to nonlinear models Harmonics generated in the nonlinear range.