Ara es mostren els items 1-20 de 52

• #### A characterization of isochronous centres in terms of symmetries ﻿

(2000)
Article
Accés obert
We present a description of isochronous centres of planar vector fields $X$ by means of their groups of symmetries. More precisely, given a normalizer $U$ of $X$ (i.e., $[X,U]=\mu X$, where $\mu$ is a scalar function), we ...
• #### A note on the periodic orbits and topological entropy of graph maps ﻿

(2000)
Article
Accés obert
This paper deals with the relationship between the periodic orbits of continuous maps on graphs and the topological entropy of the map. We show that the topological entropy of a graph map can be approximated by the entropy ...

(2000)
Article
Accés obert

(2001)
Article
Accés obert
• #### An invertible contraction that is not C<sup>1</sup>-linearizable ﻿

(2004)
Article
Accés obert
We present an example of a smooth invertible contraction in aninfinite-dimensional Hilbert space that is not locally ${\mathcalC}^{1}$-linearizable near its fixed point.
• #### Analysis of a viscoelastic spring-mass model ﻿

(2003)
Article
Accés obert
In this paper we consider a linear wave equation with strong damping and dynamical boundary conditions as an alternative model for the classical spring-mass-damper ODE. Our purpose is to compare analytically these two ...
• #### Analysis of periodic solutions of the system Janus - Epimetheus ﻿

(Universitat Politècnica de Catalunya, 2016-07)
Treball Final de Grau
Accés obert
Desenvolupament d'un model 2-dimensional per el sistema coorbital de Janus i Epimetheus al voltant de Saturn, afegint l'aplanament del planeta. Demostracio d'un teorema de simetries sobre les equacions de moviment i analisi ...
• #### Assessment of the depth of anesthesia based on symbolic dynamics of the EEG ﻿

(2010)
Comunicació de congrés
Accés obert
Methodologies based on symbolic dynamics have successfully demonstrated to reflect the nonlinear behavior of biological signals. In the present study, symbolic dynamics was applied to the electroencephalogram (EEG) in ...
• #### Asymptotic behaviour of the domain of analyticity of invariant curves of the standard map ﻿

(1999)
Article
Accés obert
In this paper we consider the standard map, and we study the invariant curve obtained by analytical continuation, with respect to the perturbative parameter E, of the invariant circle of rotation number the golden mean ...
• #### Axiomatic definition of the topological entropy on the interval ﻿

(2000)
Article
Accés obert
Summary. The aim of this paper is to give an axiomatic definition of the topological entropy for continuous interval maps and, in such a way, to shed some more light on the importance of the different properties of the ...
• #### Coarse-grained probabilistic automata mimicking chaotic systems ﻿

(2003-07-24)
Article
Accés obert
Discretization of phase space usually nullifies chaos in dynamical systems. We show that if randomness is associated with discretization dynamical chaos may survive and be indistinguishable from that of the original chaotic ...
• #### Computation of the invariant manifolds of infinity in the restricted circular planar three body problem with the parametrization method ﻿

(Universitat Politècnica de Catalunya, 2017-05)
Projecte Final de Màster Oficial
Accés obert
This work analyses the parabolic stable manifolds of the periodic orbits at infinity for the Restricted Planar Circular Three Body Problem. Using the parametrization method we prove the existence of such manifold and we ...
• #### De la mecànica celeste als sistemes dinàmics: un camí d'anar i tornar ﻿

(2006-05-17)
Audiovisual
Accés obert
La Mecànica Celeste estudia el moviment dels astres i, en general, tot tema relacionat amb el problema dels N cossos i les seves aplicacions a la ciència espacial. Podem considerar que el seu origen remot és el coneixement ...
• #### Differentiable invariant manifolds for partially hyperbolic tori and a lambda lemma ﻿

(2000)
Article
Accés obert
We consider differentiable maps having an invariant torus with normal behavior having a central part. We prove the existence and regularity of pseudostable manifolds and regularity with respect to parameters. Then we ...

(2001)
Article
Accés obert
• #### Effective stability in reversible systems ﻿

(1997)
Article
Accés obert
In this paper we present a procedure to put in normal form a nearly-integrable reversible system, not necessarily a Hamiltonian system. Furthermore, non-resonant stability estimates are obtained. As an application we discuss ...
• #### El problema dels deu Martinis ﻿

(2005-03-09)
Audiovisual
Accés obert
"El problema dels 10 martinis fou plantejat el 1981 pel matemàtic Marc Kac i es pregunta per l'estructura cantoriana de l'espectre de l’operador «almost Mathieu» o de Harper. En aquesta xerrada exposarem les motivacions ...
• #### Emotional inertia: a key to understanding psychotherapy process and outcome ﻿

(2014-09-01)
Article
Accés restringit per política de l'editorial
The processes underlying psychotherapeutic change have increasingly been emphasized in both research and clinical practice. Nonlinear dynamical systems theory (NDS) offers a transdisciplinary scientific approach to the ...

(2007-10)
Presentació
Accés obert
• #### Exponential decay in one-dimensional porous-thermo-elasticity ﻿

(2004)
Article
Accés obert
This paper concerns the one dimensional problem of the porous-thermo-elasticity. Two kinds of dissipation process are considered: the viscosity type in the porous structure and the thermal dissipation. It is known that ...