Search results for "Linea"

Nonlinear resonances and some of their applications to information processing

2021

The study of resonance phenomena in nonlinear dynamical systems has drawn considerable attention for years. The most studied nonlinear resonance is undoubtedly the famous stochastic resonance, which consists of perturbing a nonlinear system with an appropriate amount of noise to enhance the detection of a subthreshold input signal. Since the introduction of stochastic resonance in the context of climate dynamics, it was later observed that a deterministic high frequency perturbation can replace noise leading to vibrational resonance. Even if this latter resonance was investigated in many areas of science for more than two decades now, it is still receiving attentions. It is the subject of t…

High bit rate optical pulses sources generation and microstructured chalcogenide fibers characterizations

2011

This memory of thesis s' registered voter in the context of the FUTUR project financed by l'ANR and concerning the development of optical finctions fot the high bit-rate transmissions in the Network heart and carries on very high rates optical fibers sources generation and the optical chalcogenide microstructured fiber charaterization. For this purpose, we study the linear and non-linear characteristics of microstructured chalcogenide fibers conceived and realized in various collaborations within the framework of the ANR FUTUR project. For that a great number of characterizations methods were developed giving a comparison between a standard single mode fiber and there microstructured chalco…

Fiber-based light source for biomedical applications

2013

This manuscript presents the work done concerning the development of a light source used for biomedical imaging and more particularly for coherent Raman scattering imaging. In fact an efficient broadcasting of these ones is hampered by the need of two synchronized and wavelength shifted pulses. As so, the handiness and frequency conversion capabilities of nonlinear fiber optics are used to circumvent this technological lock. First of all, an easy wavelength tunable source is set by the use of the self-shifting in optical frequency of a soliton. A study of the main fiber parameters lead to shifts of 320 to more than 500 nm which allows interesting molecular resonances imaging (≈ 1000-4000 cm…

Effet du couplage non linéaire dans un système de sine-Gordon modifié

2016

National audience; Cette Communication porte sur une étude numérique visant à montrer les conditions d'existence du phénomène de supratransmission dans un milieu gouverné par l'équation de sine-gordon à couplage mixte: le couplage linéaire pur étant associé à un couplage non linéaire. Nous montrons également l'effet de la variation du coefficient du couplage non linéaire sur l'amplitude de seuil du signal excitateur nécessaire pour déclencher le phénomène de supratransmission dans le milieu, en maintenant constant le coefficient du couplage linéaire pur.

Analysis of errors caused by incomplete knowledge of material data in mathematical models of elastic media

2011

Reliable numerical solution of a class of nonlinear elliptic problems generated by the Poisson-Boltzmann equation

2020

We consider a class of nonlinear elliptic problems associated with models in biophysics, which are described by the Poisson-Boltzmann equation (PBE). We prove mathematical correctness of the problem, study a suitable class of approximations, and deduce guaranteed and fully computable bounds of approximation errors. The latter goal is achieved by means of the approach suggested in [S. Repin, A posteriori error estimation for variational problems with uniformly convex functionals. Math. Comp., 69:481-500, 2000] for convex variational problems. Moreover, we establish the error identity, which defines the error measure natural for the considered class of problems and show that it yields computa…

Perceived Burden among Spouse, Adult Child and Parent Caregivers

2018

Harmonic Balance Method and Stability of Discontinuous Systems

2019

The development of the theory of discontinuous dynamical systems and differential inclusions was not only due to research in the field of abstract mathematics but also a result of studies of particular problems in mechanics. One of first methods, used for the analysis of dynamics in discontinuous mechanical systems, was the harmonic balance method developed in the thirties of the 20th century. In our work the results of analysis obtained by the method of harmonic balance, which is an approximate method, are compared with the results obtained by rigorous mathematical methods and numerical simulation. peerReviewed

A more efficient second order blind identification method for separation of uncorrelated stationary time series

2016

The classical second order source separation methods use approximate joint diagonalization of autocovariance matrices with several lags to estimate the unmixing matrix. Based on recent asymptotic results, we propose a novel unmixing matrix estimator which selects the best lag set from a finite set of candidate sets specified by the user. The theory is illustrated by a simulation study. peerReviewed

Il percorso temporale soggettuale come linea guida del macro-processo psicoanalitico

2022

L’autore, con il seguente scritto, propone una sua personale rivisitazione della lettura del processo psicoanalitico, partendo da un percorso soggettuale che si sviluppa a partire dalle prime relazioni con il caregiver, all’interno di un funzionamento generale dei sistemi dinamici complessi non lineari. Viene proposto, rispetto ad ogni passaggio (coscienza - coscienza della coscienza - creatività) come evoluzione del processo esposto precedentemente da Minolli (2015), la costruzione di un percorso temporale soggettuale all’interno dell’auto-(geno-feno)-organizzazione (Morin, 1980). Tale lettura del macro-processo (che interessa lunghi periodi del percorso analitico), dovrà essere successiva…