Now showing items 48-67 of 116

    First order logic of random sparse structures 

    Larrauri Borroto, Lázaro Alberto (Date of defense: 2023-03-03)

    (English) This work is dedicated to the study several models of random structures from the perspective of first-order logic. We prove that the asymptotic probabilities of first-order statements converge in a general model ...

    Flexoelectricity at surface instabilities and stress singularities 

    Mohammadi, Hossein (Date of defense: 2023-06-16)

    (English) The flexoelectric effect, the two-way linear coupling between strain gradient and electric polarization (direct flexoelectricity) or electric field gradient and strain (converse flexoelectricity) universally ...

    Funciones de complejidad y su relación con las familias abstractas de lenguajes 

    Gabarró, Joaquim (Date of defense: 1983-01-01)

    Galoisian approach to supersymmetric quantum mechanics 

    Acosta Humanez, Primitivo Belén (Date of defense: 2009-07-02)

    Esta tesis versa sobre el punto de vista desde la Teoría de Galois Diferencial hacia la mecánica cuántica supersimétrica. El objeto principal considerado aquí es la ecuación deSchrödinger estacionaria no relativista, ...

    Generalized Delaunay triangulations : graph-theoretic properties and algorithms 

    Cano Vila, María del Pilar (Date of defense: 2020-06-25)

    This thesis studies different generalizations of Delaunay triangulations, both from a combinatorial and algorithmic point of view. The Delaunay triangulation of a point set S, denoted DT(S), has vertex set S. An edge uv ...

    Genomics tools in the cloud: the new frontier in omics data analysis 

    Barcelona Cabeza, Rosa (Date of defense: 2021-10-19)

    Substantial technological advancements in next generation sequencing (NGS) have revolutionized the genomic field. Over the last years, the speed and throughput of NGS technologies have increased while their costs have ...

    Geometrical aspects of contact mechanical systems and field theories 

    Rivas Guijarro, Xavier (Date of defense: 2021-12-17)

    Many important theories in modern physics can be stated using the tools of differential geometry. It is well known that symplectic geometry is the natural framework to deal with autonomous Hamiltonian mechanics. This admits ...

    Global Hamiltonian dynamics on singular symplectic manifolds 

    Oms, Cédric (Date of defense: 2020-10-02)

    In this thesis, we study the Reeb and Hamiltonian dynamics on singular symplectic and contact manifolds. Those structures are motivated by singularities coming from classical mechanics and fluid dynamics. We start by ...

    Global instability in Hamiltonian systems 

    Schaefer, Rodrigo Gonçalves (Date of defense: 2018-07-11)

    In Chapters 1 and 2 of this thesis, we prove that for any non-trivial perturbation depending on any two independent harmonics of a pendulum and a rotor there is global instability. The proof is based on the geometrical ...

    Graph enumeration and random graphs 

    Ramos Garrido, Lander (Date of defense: 2017-03-27)

    In this thesis we use analytic combinatorics to deal with two related problems: graph enumeration and random graphs from constrained classes of graphs. We are interested in drawing a general picture of some graph families ...

    Graph labelings and decompositions by partitioning sets of integers 

    Moragas Vilarnau, Jordi (Date of defense: 2010-06-14)

    Aquest treball és una contribució a l'estudi de diferents problemes que sorgeixen de dues àrees fortament connexes de la Teoria de Grafs: etiquetaments i descomposicions. Molts etiquetaments de grafs deuen el seu origen ...

    High-performance computing fluid-structure interaction model of bioprosthetic aortic valve replacements 

    Oks, David (Date of defense: 2023-07-17)

    (English) Computational modeling and simulation (CM&S) provides a powerful cost- and time-efficient tool to access detailed mechanistic information of biomedical problems, which is not accessible in either clinical imaging ...

    Homoclinic and chaotic phenomena to L3 in the restricted 3-Body Problem 

    Giralt Miron, Mar (Date of defense: 2022-11-25)

    (English) The Restricted 3-Body Problem models the motion of a body of negligible mass under the gravitational influence of two massive bodies, called the primaries. If the primaries perform circular motions and the ...

    Hybrid cell-centred/vertex model for multicellular systems 

    Mosaffa, Payman (Date of defense: 2017-11-11)

    This thesis presents a hybrid vertex/cell-centred approach to mechanically simulate planar cellular monolayers undergoing cell reorganisation. Cell centres are represented by a triangular nodal network, while the cell ...

    Integrable systems on b-symplectic manifolds 

    Kiesenhofer, Anna (Date of defense: 2016-12-21)

    The study of b-symplectic manifolds was initiated in 2012 by the works of Victor Guillemin, Eva Miranda and Ana Rita Pires (Adv. Math. 264 (2014), 864¿896). These manifolds, which can be understood as symplectic manifolds ...

    Interaction of spiral waves in the general complex Ginzburg-Landau equation 

    Aguareles Carrero, Maria (Date of defense: 2007-07-23)

    Molts sistemes físics tenen la propietat que la seva dinàmica ve definida per algun tipus de difussió espaial en competició amb un fenòmen de reacció, com per exemple en el cas de dos components químics que reaccionen al ...

    Inverse Jacobian and related topics for certain superelliptic curves 

    Somoza Henares, Anna (Date of defense: 2019-03-28)

    Given an elliptic curve E over the complex numbers (CC) given by y^2 = x^3 + ax + b, there exists a lattice L in CC such that the group E(CC) of complex points on E is isomorphic to the complex analytic group CC/L. This ...

    Lattice-based zero-knowledge proofs of knowledge 

    Martínez Pinilla, Ramiro (Date of defense: 2023-09-29)

    (English) The main goal of this dissertation is to develop new lattice-based cryptographic schemes. Most of the cryptographic protocols that each and every one of us use on a daily basis are only secure under the assumption ...

    Local preconditioning for parallel iterative solvers 

    Córdoba Pañella, Paula (Date of defense: 2022-04-22)

    This thesis aims at improving the convergence of iterative solvers, used for algebraic systems coming from the discretization of partial differential equations (PDE), in the context of large scale simulations and high ...

    Locally adaptive phase-field models and transition to fracture 

    Muixí Ballonga, Alba (Date of defense: 2020-11-30)

    This thesis proposes a new computational model for the efficient simulation of crack propagation, through the combination of a phase-field model in small subdomains around crack tips and a discontinuous model in the rest ...