Ara es mostren els items 25-44 de 81

    • Effective stability in reversible systems 

      Delshams Valdés, Amadeu; Lázaro Ochoa, José Tomás (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 

      Puig Sadurní, Joaquim (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 

      Bornas Agustí, F. Xavier; Noguera Batlle, Miquel; Pincus, David; Buela Casal, Gualberto (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 ...
    • Empirical gramians and balanced truncation for model reduction of nonlinear systems 

      Ras Sabido, Antoni (2007-10)
      Presentació
      Accés obert
    • Existence of invariant tori in skew-product systems: A computer assisted approach 

      Sandín Vidal, Eric (Universitat Politècnica de Catalunya, 2020-01)
      Projecte Final de Màster Oficial
      Accés obert
      This work is a computer assisted approach to the study of invariant manifolds in skew-product dynamical systems. More specifically, the existence of an invariant tori under a quasi-periodic perturbation of our system. The ...
    • Exponential decay in one-dimensional porous-thermo-elasticity 

      Sánchez Casas, José Pablo; Quintanilla de Latorre, Ramón (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 ...
    • Exponential stability in thermoelasticity with microtemperatures 

      Sánchez Casas, José Pablo; Quintanilla de Latorre, Ramón (2003)
      Article
      Accés obert
      This article is concerned with a linear theory for elastic materials with inner structure, whose particles in addition to the classical displacement, possess microtemperatures. In the main part of the paper we restrict ...
    • General dynamics of pulsed digital oscillators 

      Domínguez Pumar, Manuel; Pons Nin, Joan; Ricart Campos, Jordi (IEEE, 2008-02-08)
      Article
      Accés obert
      The objective of this work is to analyze pulsed digital oscillators (PDOs), as dynamical systems. It is proved that under some conditions, the bitstream at the output of the oscillator is that of the sign of a sampled ...
    • Hamiltonian systems with orbits covering densely submanifolds of small codimension 

      Fontich i Julià, Ernest; Martín de la Torre, Pablo (2000)
      Article
      Accés obert
      The existence of a transition chain in a Hamiltonian system leads to the existence of orbits shadowing it, if some lambda lemma can be applied. This fact has been used to prove the existence of diffusion in perturbations ...
    • High order dynamical systems approaches for low-thrust station-keeping of libration point orbits 

      Gao, Chen; Masdemont Soler, Josep; Gómez, Gerard; Chen, Jianlin; Yuan, Jianping (2022-01-01)
      Article
      Accés obert
      We derive two families of low-thrust station-keeping control procedures based on the dynamical properties of the phase space near libration point orbits. The first family is obtained as the limit of impulsive maneuvers, ...
    • Homoclinic orbits to invariant tori in Hamiltonian systems 

      Delshams Valdés, Amadeu; Gutiérrez Serrés, Pere (1998)
      Article
      Accés obert
      We consider a perturbation of an integrable Hamiltonian system which possesses invariant tori with coincident whiskers (like some rotators and a pendulum). Our goal is to measure the splitting distance between the perturbed ...
    • Horseshoe periodic orbits for saturn coorbital satellites 

      Llibre Saló, Jaume; Ollé Torner, Mercè (2000)
      Article
      Accés obert
      We consider the motion of coorbital satellites in the framework of the Restricted Three-Body problem for u=6.5*10^(-9). We show a mechanism to generate horsehoe periodic orbits and we compute some families of horseshoe ...
    • Integrable systems on singular symplectic manifolds: from local to global 

      Miranda Galcerán, Eva; Cardona, Robert (2021-02-03)
      Report de recerca
      Accés obert
      In this article, we consider integrable systems on manifolds endowed with symplectic structures with singularities of order one. These structures are symplectic away from a hypersurface where the symplectic volume goes ...
    • Kolmogorov Theorem Revisited 

      Villanueva Castelltort, Jordi (2004)
      Report de recerca
      Accés obert
      Kolmogorov Theorem on the persistence of invariant tori of real analytic Hamiltonian systems is revisited. In this paper we are mainly concerned with the lower bound on the constant of the Diophantine condition required ...
    • A la recerca de l'estabilitat efectiva dels asteroids trojans : algunes idees constructives de tècniques KAM sense ssar coordenades acció-angle 

      Jorba, Angel; Llave Canosa, Rafael de la; Villanueva Castelltort, Jordi (2000)
      Text en actes de congrés
      Accés obert
      Xerrada pel Seminari de Sistemes Dinamics UB-UPC. Barcelona, dimecres 19 de gener de 2000. Els trojans son una familia d'asteroids amb orbites situades no molt lluny del punt $L_5$ del sistema Sol-Jupiter. Si integrem ...
    • Lindstedt series for lower dimensional tori 

      Jorba, Angel; Llave Canosa, Rafael de la; Zou, Maorong (1995)
      Article
      Accés obert
      We consider the existence and effective computation of low-dimensional (less independent frequencies than degrees of freedom) invariant tori of a near-integrable system. Lindstedt method is a systematic procedure to compute ...
    • Modeling tails and bridges in galaxy interactions with the restricted three body problem 

      García Gutierrez, Albert (Universitat Politècnica de Catalunya, 2021-01)
      Projecte Final de Màster Oficial
      Accés obert
      Galaxy interaction is a common feature in our universe but the dynamics behind it is still not fully understood. More data is becoming available lately and every time it is more precise. However, we need mathematical and ...
    • Modelling and analysis of crayfish competition 

      Solà Lorente, Jaume (Universitat Politècnica de Catalunya, 2015-09)
      Treball Final de Grau
      Accés restringit per acord de confidencialitat
      Realitzat a/amb:   Technische Universität München. Fakultät für Mathematik
    • Modelos dinámicos en finanzas 

      Carrillo Menéndez, Santiago (2014-01-17)
      Altres
      Accés obert
      El problema de la modelización dinámica en finanzas tiene mucho que ver con el tipo de problema que se pretende estudiar. Es preciso tener en cuenta el subyacente así como las magnitudes que se pretende estimar para ...
    • Nonlinear dynamics of replication modes in tunable deleterious fitness landscape 

      Fornés Tugores, Joan (Universitat Politècnica de Catalunya, 2017-07)
      Treball Final de Grau
      Accés restringit per decisió de l'autor
      Realitzat a/amb:   Centre de Recerca Matemàtica
      We analyze a system of nonlinear ordinary differential equations describing the intracellular amplification dynamics of viral RNA genomes. The replication modes considered range between two extremes given by the so-called ...