Recursos de colección

ORBi Open Repository and Bibliography (327.254 recursos)

In may 2007, the ULg's Administrative Board (joined in June 2007 by the FUSAGx) decided to create an institutional repository and defined a strong institutional self-archiving policy to increase the visibility, accessibility and impact of the University's publications (Board's decision). This decision led to the official launch, in November 2008, of the ORBi platform including both the Academic Bibliography and the Institutional Repository of the Wallonia-Europe University Academy.

Physical, chemical, mathematical & earth Sciences => Mathematics

Mostrando recursos 1 - 20 de 240

  1. Couplages FEM-BEM faibles et optimisés pour des problèmes de diffraction harmoniques en acoustique et en électromagnétisme

    Caudron, Boris
    In this doctoral dissertation, we propose new methods for solving acoustic and electromagnetic three-dimensional harmonic scattering problems for which the scatterer is penetrable and inhomogeneous. The resolution of such problems is key in the computation of sonar and radar cross sections (SCS and RCS). However, this task is known to be difficult because it requires discretizing partial differential equations set in an exterior domain. Being unbounded, this domain cannot be meshed thus hindering a volume finite element resolution. There are two standard approaches to overcome this difficulty. The first one consists in truncating the exterior domain and renders possible a...

  2. Enhanced Laplace transform and holomorphic Paley-Wiener theorems

    Dubussy, Christophe
    In this talk we explain how the Kashiwara-Schapira isomorphism for the enhanced Laplace transform can be seen as the usual Laplace transform for enhanced distributions. From this observation, we derive two holomorphic Paley-Wiener theorems which can be seen as tempered versions of the classical Polya's representation theorem and Méril's theorem. In particular, we show how the contour integrations naturally arise in this context.

  3. Estimation from cross-sectional data under a semiparametric truncation model

    De uña Alvarez, Jacobo; Heuchenne, Cédric; Laurent, Géraldine

  4. Nonparametric regression with cross-sectional data: an alternative to conditional product-limit estimators

    Heuchenne, Cédric; Laurent, Géraldine

  5. Quadratizations in nonlinear binary optimization: new results

    Crama, Yves

  6. Dualities for Boolean Contact Algebras

    Raskin, Julien
    The well-known de Vries duality, established by H. de Vries in 1962, states that the category of compact Hausdorff spaces is dually equivalent to that of de Vries algebras. The notion of Boolean contact algebra (BCA) was developed independently in the context of region-based theory of space. Düntsch and Winter established a representation theorem for BCAs, showing that every BCA is isomorphic to a dense subalgebra of the regular closed sets of a T_1 weakly regular space. It appears that BCAs are a direct generalization of de Vries algebras, and that the representation theorem for complete BCAs generalizes de Vries...

  7. Kernelized goodness-of- fit tests for discrete variables

    Ernst, Marie; Swan, Yvik
    In this talk, we review goodness-of-fit tests for discrete distributions and propose an alternative family of tests based on a kernelized Stein discrepancy. This measure is an expectation based on Stein’s operator associated to the target distribution. It has some useful theoretical and asymptotic properties and, furthermore, it can be empirically estimated. A key ingredient for this procedure is the choice of an adequate kernel which may be related to the target distribution. In order to illustrate the efficiency of these tests, we resort to empirical analysis by simulations based on the Binomial case and “close” distributions with respect to the total variation distance.

  8. Generalized Pointwise Hoelder Spaces Defined via Admissible Sequences

    Kreit, Damien; Nicolay, Samuel
    Peer reviewed

  9. Analyse Mathématique : Fonctions définies sur une partie de la droite réelle

    Nicolay, Samuel
    Ce livre s’adresse aux étudiants désireux d’obtenir des bases rigoureuses en analyse. L’auteur s’est donné pour objectif d’aborder la théorie des fonctions à une variable de manière complète et détaillée. De nombreuses excursions théoriques, sortant des sentiers habituellement empruntés pour un tel projet, sont proposées afin de donner au lecteur une vision plus globale de la théorie. Il s’agit d’un outil de travail idéal pour aborder le programme de mathématiques du supérieur (niveau L2). Cet ouvrage est illustré par de nombreuses figures et des exemples traités en détail. Les sujets abordés sont : la logique et la théorie des ensembles, les...

  10. A study of histograms of wavelet coefficients of the Mars topography to determine its scaling properties

    Kleyntssens, Thomas; Reynaerts, Laura; Nicolay, Samuel
    Peer reviewed

  11. Diametral dimensions and some applications to spaces Snu

    Demeulenaere, Loïc
    The "classic" diametral dimension is a topological invariant which characterizes Schwartz and nuclear locally convex spaces. Besides, there exists a second diametral dimension which is conjectured to be equal to the first one (on Fréchet-Schwartz spaces). The first part of this thesis is dedicated to the study of this conjecture. We present several positive partial results in metrizable spaces (in particular in Köthe sequence spaces and Hilbertizable spaces) and some properties which provide the equality of the two diametral dimensions (such as the Delta-stability, the existence of prominent bounded sets, and the property Omega bar). Then, we describe the construction of some non-metrizable locally...

  12. Some generalizations of the Pascal triangle: base 2 and beyond

    Stipulanti, Manon
    The binomial coefficient (u,v) of two finite words u and v (on a finite alphabet) is the number of times the word v appears inside the word u as a subsequence (or, as a "scattered" subword). For instance, (abbabab,ab)=4. This concept naturally extends the classical binomial coefficients of integers, and has been widely studied for about thirty years (see, for instance, Simon and Sakarovitch). In this talk, I present the research lead from October 2015: I give the main ideas that lead to an extension of the Pascal triangles to base-2 expansions of integers. After that, I extend the work...

  13. Pascal-like triangles: base 2 and beyond

    Stipulanti, Manon
    The binomial coefficient (u,v) of two finite words u and v (on a finite alphabet) is the number of times the word v appears inside the word u as a subsequence (or, as a "scattered" subword). For instance, (abbabab,ab)=4. This concept naturally extends the classical binomial coefficients of integers, and has been widely studied for about thirty years (see, for instance, Simon and Sakarovitch). In this talk, I present the research lead since October 2015: I give the main ideas that give an extension of the Pascal triangle to base-2 expansions of integers and also give an overview of the...

  14. From combinatorial games to shape-symmetric morphisms

    Rigo, Michel
    Siegel suggests in his book on combinatorial games that quite simple games provide us with challenging problems: ``No general formula is known for computing arbitrary Grundy values of Wythoff's game. In general, they appear chaotic, though they exhibit a striking fractal-like pattern.''. This observation is the first motivation behind this chapter. We present some of the existing connections between combinatorial game theory and combinatorics on words. In particular, multidimensional infinite words can be seen as tiling of $N^d$. They naturally arise from subtraction games on $d$ heaps of tokens. We review notions such as $k$-automatic, $k$-regular or shape-symmetric multidimensional words....

  15. An optimized domain decomposition method between interior and exterior domains for harmonic, penetrable and inhomogeneous electromagnetic scattering problems

    Caudron, Boris; Geuzaine, Christophe; Antoine, Xavier
    Peer reviewed

  16. A well-conditioned weak coupling between interior and exterior domains for harmonic electromagnetic scattering

    Caudron, Boris; Antoine, Xavier; Geuzaine, Christophe
    Peer reviewed

  17. Combinatoire des mots : résultats classiques et avancées récentes

    Rigo, Michel
    Dans cet exposé ne nécessitant aucun prérequis, je présenterai quelques grands thèmes issus de la combinatoire des mots (i.e., des suites prenant leurs valeurs dans un ensemble fini de symboles) et leurs possibles applications en théorie des nombres, en dynamique symbolique ou en géométrie discrète. En guise d'illustration, considérons le problème suivant. Un carré est la répétition de deux facteurs consécutifs identiques. Ainsi, le mot "entente" débute par le carré (ent)^2 et se aussi termine par le carré (nte)^2. Etant donné un alphabet de taille fixée, on souhaite construire un mot, le plus long possible, évitant un motif particulier. On se...

  18. Sequences, Groups, and Number Theory


    This collaborative book presents recent trends on the study of sequences, including combinatorics on words and symbolic dynamics, and new interdisciplinary links to group theory and number theory. Other chapters branch out from those areas into subfields of theoretical computer science, such as complexity theory and theory of automata. The book is built around four general themes: number theory and sequences, word combinatorics, normal numbers, and group theory. Those topics are rounded out by investigations into automatic and regular sequences, tilings and theory of computation, discrete dynamical systems, ergodic theory, numeration systems, automaton semigroups, and amenable groups. This volume is...

  19. INVESTIGATING LUNAR TOPOGRAPHIC PROPERTIES AT DIFFERENT SPATIAL SCALES USING DATA FROM THE LUNAR ORBITER LASER ALTIMETER AND THE WAVELET LEADERS METHOD

    Lemelin, Myriam; Daly, Mike; Deliège, Adrien
    Peer reviewed

  20. Des mathématiques derrière l'intelligence artificielle

    Deliège, Adrien

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