Enviaments recents

  • Random combinatorial structures with low dependencies : existence and enumeration 

    Perarnau Llobet, Guillem (Universitat Politècnica de Catalunya, 2013-10-01)
    Tesi
    Accés obert
    En aquesta tesi s'estudien diferents problemes en el camp de la combinatòria i la teoria de grafs, utilitzant el mètode probabilístic. Aquesta tècnica, introduïda per Erdős , ha esdevingut una eina molt potent per tal de ...
  • Contribucions a la teoria de l'aresta-acoloriment de grafs : snarks i multipols 

    Vilaltella Castanyer, Joan (Universitat Politècnica de Catalunya, 2015-07-14)
    Tesi
    Accés obert
    A graph where every vertex has three neighboring vertices is a cubic graph. An edge-coloring is an assignment of colors to the edges of a graph in such a way that the edges incident to a vertex have no repeated colors. An ...
  • A cotangent bundle Hamiltonian tube theorem and its applications in reduction theory 

    Teixidó Roman, Miguel (Universitat Politècnica de Catalunya, 2015-03-27)
    Tesi
    Accés obert
    The Marle-Guillemin-Sternberg (MGS) model is an extremely important tool for the theory of Hamiltonian actions on symplectic manifolds. It has been extensively used to prove many local results both in symplectic geometry ...
  • Geometrical structures of higher-order dynamical systems and field theories 

    Prieto Martínez, Pedro Daniel (Universitat Politècnica de Catalunya, 2014-10-02)
    Tesi
    Accés obert
    Geometrical physics is a relatively young branch of applied mathematics that was initiated by the 60's and the 70's when A. Lichnerowicz, W.M. Tulczyjew and J.M. Souriau, among many others, began to study various topics ...
  • A network approach for strapdown inertial kinematic gravimetry 

    Termens Perarnau, Maria Assumpció (Universitat Politècnica de Catalunya, 2014-03-07)
    Tesi
    Accés obert
    Compared to the conventional ground measurement of gravity, airborne gravimetry is more efficient and cost-effective. Especially, the combination of GPS and INS is known to show very good performances recovering the gravity ...
  • The Removal Lemma: algebraic versions and applications 

    Vena Cros, Lluís (Universitat Politècnica de Catalunya, 2012-07-02)
    Tesi
    Accés obert
    This thesis presents some contributions in additive combinatorics and arithmetic Ramsey theory. More specifically, it deals with the interaction between combinatorics, number theory and additive combinatorics. This area ...
  • Contributions to secret sharing and other distributed cryptosystems 

    Ruiz Rodríguez, Alexandre (Universitat Politècnica de Catalunya, 2013-07-22)
    Tesi
    Accés obert
    The present thesis deals with primitives related to the eld of distributed cryptography. First, we study signcryption schemes, which provide at the same time the functionalities of encryption and signature, where the ...
  • Una Formalització de les construccions geomètriques 

    Tramuns Figueras, Eulàlia (Universitat Politècnica de Catalunya, 2012-07-18)
    Tesi
    Accés obert
    Geometric constructions have been studied by mathematicians from ancient Greece until now. Although most attention has been given by the ruler and compass, during the last decades interest in this subject has revived, and ...
  • Optimization in graphs under degree constraints. application to telecommunication networks 

    Sau Valls, Ignasi (Universitat Politècnica de Catalunya, 2009-10-16)
    Tesi
    Accés obert
    La premi ere partie de cette th ese s'int eresse au groupage de tra c dans les r eseaux de t el ecommunications. La notion de groupage de tra c correspond a l'agr egation de ux de faible d ebit dans des conduits de ...
  • Multipartite secret sharing schemes 

    Farràs Ventura, Oriol (Universitat Politècnica de Catalunya, 2010-07-27)
    Tesi
    Accés obert
    This thesis is dedicated to the study of secret sharing schemes, which are cryptographic methods to share information in a secure way. The topics that are considered in the thesis are two of the main open problems in secret ...

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