Piezoelectric actuators have received an increasing attention these last years thanks to the high resolution of displacement, high force density and fast response time that can offer piezoelectric materials. However, piezoelectric actuators are highly sensitive to environmental disturbances and typify strong nonlinearities that undeniably reduce the expected positioning accuracy. H∞ or μ-synthe...

This paper proposes the design of reconfigurable suspension systems in road vehicles. The purpose of the suspension system is to improve passenger comfort and road holding during travel and improve safety during various maneuvers. In the modeling the nonlinearities in the suspension system, the changes in the forward velocity and the change of the adhesion coefficient between the tire and the r...

Low fuel consumption and low emissions are key issues in modern internal combustion engines design. For this reason, an effective on-line control of the injection process requires the mathematical equations describing the system dynamics. The inherent nonlinearities make the modeling of the fuel-injection system hard to accomplish. Moreover, it is necessary to trade off between accuracy in repr...

The dead-zone is one of the most common hard nonlinearities in industrial actuators and its presence may drastically compromise control systems stability and performance. In this work, an adaptive variable structure controller is proposed to deal with a class of uncertain nonlinear systems subject to a non-symmetric dead-zone input. The adopted approach is primarily based on the sliding mode co...

We propose a quantum stripe ~smectic! coupled-Luttinger-liquid model for the anisotropic states which occur in two-dimensional electron systems with high-index partial Landau-level filling, n*5n2@n# . Perturbative renormalization-group calculations establish that interaction terms neglected in this model are relevant —probably driving the system into an anisotropic Wigner crystal—but for 0.4&n*...

incoming RF signals to suppress a certain diffraction modes. The set of experimental verifications with two type AO modulators operating in Raman-Nath (hard flint cell) and Bragg (TeO2 cell) regimes have been performed. With use of the analogue third order polynomial RF synthesizer [2] there were obtained a rather good suppression of two-tone second-order intermodulations in space of the second...

The use of polychromatic X-ray sources in tomographic X-ray measurements leads to nonlinear X-ray transmission effects. As these nonlinearities are not normally taken into account in tomographic reconstruction, artefacts occur, which can be particularly severe when imaging objects with multiple materials of widely varying X-ray attenuation properties. In these settings, reconstruction algorithm...

A central element in organization of financial means consists in the constitution, analysis and optimization of portfolios. As in many processes in nature, technology and economy, financial processes suffer from stochastic fluctuations and noise. Therefore, we consider stochastic differential equations [19]. As a drawback, these equations are often hard to represent and to resolve. We express t...

We propose a general Bayesian model for image segmentation with spatial coherence through a Markov Random Field prior. We also study variants of the model and their relationship. In this work we use the Matusita Distance, although our formulation admits other metric-divergences. Our main contributions in this work are the following. We propose a general MRF-based model for image segmentation. W...

Many forms of parsimony pressure are parametric, that is final fitness is a parametric model of the actual size and raw fitness values. The problem with parametric techniques is that they are hard to tune to prevent size from dominating fitness late in the evolutionary run, or to compensate for problem-dependent nonlinearities in the raw fitness function. In this paper we briefly discuss existi...