Now showing items 12-31 of 44

    Design and evaluation of navigation and control algorithms for spacecraft formation flying missions 

    Perea Virgili, Laura (Date of defense: 2010-05-21)

    Formation flying offers space-dependent disciplines such as astrophysics, astrodynamics, and geodesy, to name a few, the possibility of creating large spaceborne sensors from an array of small spacecraft flying in formation. ...

    Detection and Alignment of Vascular Structures in Intravascular Ultrasound using Pattern Recognition Techniques 

    Alberti, Marina (Date of defense: 2013-02-21)

    In this thesis, several methods for the automatic analysis of Intravascular Ultrasound (IVUS) sequences are presented, aimed at assisting physicians in the diagnosis, the assessment of the intervention and the monitoring ...

    Dynamical transport mechanisms in celestial mechanics and astrodynamics problems 

    Pérez Palau, Daniel (Date of defense: 2015-11-30)

    L’objectiu d’aquesta tesi és afegir una petita fulla a l’arbre del coneixement. En particular a la branca del sistemes dinàmics. La teoria de sistemes dinàmics és la branca de les matemàtiques que estudia l’evolució del ...

    Endpoint estimates via extrapolation theory 

    Domingo Salazar, Carlos (Date of defense: 2016-04-07)

    In this thesis, we study different variants of Rubio de Francia’s extrapolation that allow us to obtain estimates near L1. This theory is subsequently applied to deduce enpoint boundedness for the Bochner-Riesz operator ...

    Estabilitat efectiva i tors invariants de sistemes hamiltonians quasi-integrables 

    Gutiérrez i Serrés, Pere (Date of defense: 1995-06-02)

    La memòria recull contribucions a diversos aspectes del problema de l'estabilitat en sistemes hamiltonians quasi-integrables. Aquests aspectes inclouen resultats d'estabilitat efectiva, que comporten el confinament de ...

    Estudi de sistemes dinàmics mitjançant la reducció de la seva dimensió 

    Bosch Gual, Miquel (Date of defense: 1992-09-30)

    L'objectiu del treball és mostrar que alguns aspectes de certs sistemes dinàmics discrets bidimensionals poden ser estudiats mitjançant sistemes de dimensió 1 que corresponen a casos particulars o simplificacions. Els tres ...

    Evolution of Sex-Ratio in Structured Population Dynamics 

    Ripoll i Missé, Jordi (Date of defense: 2005-10-05)

    In this Thesis we address the study of some non-linear evolution equations (e.g. pde's) modelling the dynamics of sexually-reproducing structured populations, with special emphasis on biological evolution driven by natural ...

    From pixels to gestures: learning visual representations for human analysis in color and depth data sequences 

    Hernández-Vela, Antonio (Date of defense: 2015-03-09)

    The visual analysis of humans from images is an important topic of interest due to its relevance to many computer vision applications like pedestrian detection, monitoring and surveillance, human-computer interaction, ...

    Generalized Stacked Sequential Learning 

    Puertas i Prats, Eloi (Date of defense: 2014-11-04)

    Over the past few decades, machine learning (ML) algorithms have become a very useful tool in tasks where designing and programming explicit, rule-based algorithms are infeasible. Some examples of applications ...

    Human Pose Analysis and Gesture Recognition from Depth Maps: Methods and Applications 

    Reyes Estany, Miguel (Date of defense: 2017-02-27)

    The visual analysis of humans is one of the most active research topics in Computer Vision. Several approaches for body pose recovery have been recently presented, allowing for better generalization of gesture recognition ...

    Interpolación compleja de operadores lineales 

    Carro Rossell, María Jesús (Date of defense: 1988-01-30)

    El primer resultado de interpolación de operadores data del año 1911 y es debido a I. Schur. Dos años más tarde, Young prueba un resultado del mismo tipo referente a espacios Lp y a un operador L La extensión de estos ...

    Intervals de marques 

    Jorba Jorba, Lambert (Date of defense: 2003-05-26)

    El sistema de les marques s'enquadra dins del camp de l'anàlisi intervalar modal. <br/>En aquest context la tesi aporta un estudi de les operacions lineals, de la seva semàntica i sobretot de la seva operativitat quan les ...

    Invariant manifolds and bifurcations for one-dimensional and two-dimensional dissipative maps 

    Tatjer i Montaña, Joan Carles (Date of defense: 1990-03-01)

    It is known that for the study of continuous dynamical systems the discret case plays an important role because, with it we can study the continuous one by using the Poincaré return map. In the discret case we can distinguish ...

    Learning error-correcting representations for multi-class problems 

    Bautista Martín, Miguel Ángel (Date of defense: 2016-02-11)

    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 ...

    Mesura del trencament de separatrius en famílies de difeomorfismes amb punts hiperbòlics 

    Fontich Julià, Ernest (Date of defense: 1985-12-05)

    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 ...

    Mesures i probabilitats en estructures ordenades 

    Congost Iglesias, Maria Assumpta (Date of defense: 1981-01-01)

    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 ...

    Morfismos diferenciables topológicamente lisos. Caracterizaciones y aplicaciones 

    Ortega Aramburu, Joaquín Mª (Date of defense: 1972-01-01)

    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 ...

    On a Family of Degree 4 Blaschke Products 

    Canela Sánchez, Jordi (Date of defense: 2015-03-18)

    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 ...

    On Quasiperiodic Perturbations of Ordinary Differential Equations 

    Jorba i Monte, Àngel (Date of defense: 1991-10-11)

    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 ...

    On the Meromorphic Non-Integrability of Some Problems in Celestial Mechanics 

    Simon i Estrada, Sergi (Date of defense: 2007-07-09)

    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. ...