350 research outputs found
Soliton dynamics of NLS with singular potentials
We investigate the validity of a soliton dynamics behavior in the
semi-relativistic limit for the nonlinear Schr\"odinger equation in , in presence of a singular external potential.Comment: 23 page
Soliton dynamics for the generalized Choquard equation
We investigate the soliton dynamics for a class of nonlinear Schr\"odinger
equations with a non-local nonlinear term. In particular, we consider what we
call {\em generalized Choquard equation} where the nonlinear term is
. This problem is particularly interesting
because the ground state solutions are not known to be unique or
non-degenerate.Comment: 16 page
Global-local mixing for the Boole map
In the context of 'infinite-volume mixing' we prove global-local mixing for
the Boole map, a.k.a. Boole transformation, which is the prototype of a
non-uniformly expanding map with two neutral fixed points. Global-local mixing
amounts to the decorrelation of all pairs of global and local observables. In
terms of the equilibrium properties of the system it means that the evolution
of every absolutely continuous probability measure converges, in a certain
precise sense, to an averaging functional over the entire space.Comment: 15 pages, 2 figures. Final version to be published in Chaos, Solitons
& Fractal
Infinite mixing for one-dimensional maps with an indifferent fixed point
We study the properties of `infinite-volume mixing' for two classes of
intermittent maps: expanding maps with an
indifferent fixed point at 0 preserving an infinite, absolutely continuous
measure, and expanding maps with an
indifferent fixed point at preserving the Lebesgue measure. All maps
have full branches. While certain properties are easily adjudicated, the
so-called global-local mixing, namely the decorrelation of a global and a local
observable, is harder to prove. We do this for two subclasses of systems. The
first subclass includes, among others, the Farey map. The second class includes
the standard Pomeau-Manneville map mod 1. Morevoer, we use
global-local mixing to prove certain limit theorems for our intermittent maps.Comment: Final version to be published in Nonlinearity. 39 pages, 2 figure
Pomeau-Manneville maps are global-local mixing
We prove that a large class of expanding maps of the unit interval with a
-regular indifferent point in 0 and full increasing branches are
global-local mixing. This class includes the standard Pomeau-Manneville maps
mod 1 (), the Liverani-Saussol-Vaienti maps (with
index ) and many generalizations thereof.Comment: 23 pages. Final version produced for Discrete and Continuous
Dynamical Systems - Series A. Numbering of equations, references et alia
conforms to the published articl
A radial basis function neural network based approach for the electrical characteristics estimation of a photovoltaic module
The design process of photovoltaic (PV) modules can be greatly enhanced by
using advanced and accurate models in order to predict accurately their
electrical output behavior. The main aim of this paper is to investigate the
application of an advanced neural network based model of a module to improve
the accuracy of the predicted output I--V and P--V curves and to keep in
account the change of all the parameters at different operating conditions.
Radial basis function neural networks (RBFNN) are here utilized to predict the
output characteristic of a commercial PV module, by reading only the data of
solar irradiation and temperature. A lot of available experimental data were
used for the training of the RBFNN, and a backpropagation algorithm was
employed. Simulation and experimental validation is reported
Internal-wave billiards in trapezoids and similar tables
We call internal-wave billiard the dynamical system of a point particle that
moves freely inside a planar domain (the table) and is reflected by its
boundary according to this rule: reflections are standard Fresnel reflections
but with the pretense that the boundary at any collision point is either
horizontal or vertical (relative to a predetermined direction representing
gravity). These systems are point particle approximations for the motion of
internal gravity waves in closed containers, hence the name. For a class of
tables similar to rectangular trapezoids, but with the slanted leg replaced by
a general curve with downward concavity, we prove that the dynamics has only
three asymptotic regimes: (1) minimality (all trajectories are dense); (2)
there exist a global attractor and a global repellor, which are periodic and
might coincide; (3) there exists a beam of periodic trajectories, whose
boundary (if any) comprises an attractor and a repellor for all the other
trajectories. Furthermore, in the prominent case where the table is an actual
trapezoid, we study the sets in parameter space relative to the three regimes.
We prove in particular that the set for (1) is a positive-measure fractal; the
set for (2) has positive measure (giving a rigorous proof of the existence of
Arnol'd tongues for internal-wave billiards); the set for (3) has measure zero.Comment: 23 pages, 6 figure
La pratique professionnelle des psychologues pédiatriques en milieu hospitalier lors de la transition d'adolescents en milieu adulte
Cette étude porte sur la pratique clinique des psychologues pédiatriques lors de la transition de jeunes patients atteints d’une maladie chronique ou dégénérative au milieu adulte. Étant donné que leur rôle dans ce domaine a été peu étudie, cette étude vise à combler cette lacune. Nous avons mené des entretiens semi-structurés auprès de dix psychologues. L’analyse thématique des verbatims a été utilisée afin de dégager des thèmes communs aux participants. Un premier article explore la façon dont les psychologues pédiatriques définissent la transition et vise à identifier les facilitateurs et les obstacles dans leur travail, alors que le deuxième décrit les éléments qui caractérisent les différents rôles joués par les psychologues dans la transition et fait état des recommandations visant l’amélioration de la pratique dans ce domaine
Soliton dynamics of NLS with singular potentials
We investigate the validity of a soliton dynamics behavior in the semi-classical limit for the nonlinear Schroedinger equation in R^N,N≥3, in presence of a singular external potential
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