Universitat de Barcelona
Now showing items 25-44 of 44
Real life is full of multi-class decision tasks. In the Pattern Recognition field, several method- ologies have been proposed to deal with binary problems obtaining satisfying results in terms of performance. However, the ...
Se consideran familias de difeomorfismos con un punto fijo parabólico para el valor cero del parámetro y un punto fijo hiperbólico para valores mayores que cero que tengan en este caso puntos homoclínicos asociados a ...
En una primera part s'estudien els conjunts de mesures que prenen valors en un grup reticualt, per a les quals la T-aditivitat es defineix a partir de l'estructura ordenada. L'estudi realitzat a partir de les propietats ...
Esta memoria recoge algunos de los puntos fundamentales e inéditos que han aparecido al iniciar un estudio sobre los métodos espectrales en Análisis y, en particular, sobre los anillos y estructuras diferenciables. Dicho ...
This PhD thesis belongs to the area of discrete dynamical systems in the complex plane, i.e. the iteration of analytic functions in one complex variable. Given a rational map f from the Riemann sphere onto itself, we ...
In this work we study several topics concerning quasi-periodic time-dependent perturbations of ordinary differential equations. This kind of equations appear as models in many applied problems of Celestial Mechanics, and ...
In this thesis, we present a proof of the meromorphic non-integrability for some problems arising from Celestial Mechanics, as well as a new necessary condition for partial integrability in a wider Hamiltonian setting. ...
Multi Agent Systems (MAS) are computerised systems composed of autonomous software agents that interact to solve complex problems. Within a MAS, agents require some mechanism to coordinate their activities. In the MAS ...
Este proyecto hace referencia a estimaciones, en espacios funcionales, que relacionan la norma de una función y la de sus derivadas. Concretamente, nuestro principal objetivo es estudiar las estimaciones clásicas de las ...
El teorema de Kolmogorov-Arnold-Moser no asegura la estabilidad cerca de los toros m-dimensionales que se conservan para hamiltonianos casi integrables con "m" grados de libertad. Puede aparecer una difusión de trayectorias ...
The anisotropic Kepler problem was introduced by Gutzwiller as a classical mechanical system which approximates the following quantum mechanical system: the study of bound states of an electron near a donor impurity of a ...
Interpolating and sampling sequences in spaces of functions are classical subjects in complex and harmonic analysis. A sequence of points is said to be interpolating if, given any collection of values, we can find a function ...
DE LA TESIS:<br/><br/>El contenido de esta tesis se enmarca dentro del Análisis Real. En particular, trata del estudio de ciertos problemas de la teoría de pesos, (una referencia clásica sobre esta teoría es el libro de ...
Wireless Capsule Endoscopy (WCE) is a technique for inner-visualization of the entire small intestine and, thus, offers an interesting perspective on intestinal motility. The two major drawbacks of this technique are: 1) ...
This monograph is structured in four chapters. In Chapter 1, we present the context of our problem and the main results proved in this work. We describe the asymptotic behaviour of the reproducing kernel and the ...
L'objectiu principal d'aquesta tesi doctoral és l'estudi de l'efecte de les fluctuacions en poblacions acoblades en sistemes biològics, on cèl·lules en estat latent juguen un paper important. Intentant trobar el significat ...
In this thesis we consider two different problems in the theory of dynamical systems. Dynamical systems cover a wide array of subjects, from finite dimensional to infinite dimensional, from analytic to statistical viewpoints ...
We have divided this thesis in four parts:<br/><br/>a) PART I: Exact symplectic geometry (introduction of the problems). This part contains the basic tools of symplectic geometry and outlines the four subjects that we have ...
In this dissertation, we show the effectiveness of the exploitation of the Circular Restricted Three - Body Problem (CR3BP) in the Earth - Moon framework. We study the motion of a massless particle under the gravitational ...
In the early 1970 fs, R. Coifman and G. Weiss, generalizing the techniques introduced by A. Calderon, developed a method for transferring abstract convolution type operators, defined on general topological groups, and their ...
