Browsing by Subject "Dynamical systems"

Now showing items 21-40 of 87

    • Computer-Assited Proofs in Dynamics 

      Fernández Pinto, Aarón (Universitat Politècnica de Catalunya, 2020-10)
      Master thesis
      Restricted access - author's decision
      Interval analysis is presented as a solution to obtain rigorous results using computers. We present a methodology of computer-assisted proofs which involves the use of interval computations. In this thesis we introduce the ...

    • De la mecànica celeste als sistemes dinàmics: un camí d'anar i tornar 

      Simó, Carles (2006-05-17)
      Audiovisual
      Open Access
      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 ...

    • Detection of Lagrangian Coherent Structures in oceanic flows 

      Bruera, Renzo (Universitat Politècnica de Catalunya, 2021-07)
      Master thesis
      Open Access
      The Atlantic Meridional Overturning Circulation (AMOC) is a complex system of shallow and deep currents in the Atlantic Ocean which plays a crucial role in the regulation of the Earth's climate. Lagrangian Coherent Structures ...

    • Differentiable invariant manifolds for partially hyperbolic tori and a lambda lemma 

      Fontich i Julià, Ernest; Martín de la Torre, Pablo (2000)
      Article
      Open Access
      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 ...

    • Dynamic modeling of biogranules in wastewater treatment 

      Da Silva Álvarez, Cristopher (Universitat Politècnica de Catalunya, 2024-07-09)
      Master thesis
      Open Access
      This Master's thesis focuses on partial nitrification, examining the competitive dynamics between ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). The research aims to develop a model for determining ...

    • Dynamics and bifurcation near the transition from stability to complex instability 

      Ollé Torner, Mercè; Pacha Andújar, Juan Ramón; Villanueva Castelltort, Jordi (2001)
      Article
      Open Access

    • Effective stability in reversible systems 

      Delshams Valdés, Amadeu; Lázaro Ochoa, José Tomás (1997)
      Article
      Open Access
      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
      Open Access
      "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
      Restricted access - publisher's policy
      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)
      Lecture
      Open Access

    • Existence of invariant tori in skew-product systems: A computer assisted approach 

      Sandín Vidal, Eric (Universitat Politècnica de Catalunya, 2020-01)
      Master thesis
      Open Access
      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
      Open Access
      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
      Open Access
      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 ...

    • Forced flow reversal in ferrofluidic Couette flow via alternating magnetic field 

      Altmeyer, Sebastian Andreas (2024-11-01)
      Article
      Open Access
      Time-dependent boundary conditions are very common in natural and industrial flows and by far no exception. An example of this is the movement of a magnetic fluid forced due to temporal modulations. In this study, we used ...

    • General dynamics of pulsed digital oscillators 

      Domínguez Pumar, Manuel; Pons Nin, Joan; Ricart Campos, Jordi (IEEE, 2008-02-08)
      Article
      Open Access
      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
      Open Access
      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
      Open Access
      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
      Open Access
      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
      Open Access
      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)
      Research report
      Open Access
      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 ...