• Gaussian distributions, Jacobi group, and Siegel-Jacobi space 

  Molitor, Mathieu (Brasil, 2014)

  Let N be the space of Gaussian distribution functions over ℝ, regarded as a 2-dimensional statistical manifold parameterized by the mean μ and the deviation σ. In this paper, we show that the tangent bundle of N , endowed ...
• Non-uniform Specification and Large Deviations for Weak Gibbs Measures 

  Varandas, Paulo César Rodrigues Pinto (2012)

  We establish bounds for the measure of deviation sets associated to continuous observables with respect to not necessarily invariant weak Gibbs measures. Under some mild assumptions, we obtain upper and lower bounds for ...
• Robust Exponential Decay of Correlations for Singular-Flows 

  Araujo, Vitor; Varandas, Paulo César Rodrigues Pinto (2012)

  We construct open sets of C k (k ≥ 2) vector fields with singularities that have robust exponential decay of correlations with respect to the unique physical measure. In particular we prove that the geometric Lorenz attractor ...
• Bayesian inference for power law processes with applications in repairable systems 

  Oliveira, Maristela Dias de; Colosimo, Enrico A.; Gilardoni, Gustavo L. (2012)

  Statistical models for recurrent events are of great interest in repairable systems reliability and maintenance. The adopted model under minimal repair maintenance is frequently a nonhomogeneous Poisson process with the ...
• Optimization of the weights and asymmetric activation function family of neural network for time series forecasting 

  Gomes, Gecynalda S. da S.; Ludermir, Teresa B. (2013)

  The use of neural network models for time series forecasting has been motivated by experimental results that indicate high capacity for function approximation with good accuracy. Generally, these models use activation ...
• Dominated splittings for flows with singularities 

  Araujo, Vitor; Arbieto, Alexander; Salgado, Luciana (2013)

  We obtain sufficient conditions for an invariant splitting over a compact invariant subset of a C1 flow Xt to be dominated. In particular, we reduce the requirements to obtain sectional hyperbolicity and hyperbolicity.
• A Particle System with Explosions: Law of Large Numbers for the Density of Particles and the Blow-Up Time 

  Franco, Tertuliano; Groisman, Pablo (2012)

  Consider a system of independent random walks in the discrete torus with creation-annihilation of particles and possible explosion of the total number of particles in finite time. Rescaling space and rates for diffusion/ ...
• Construction of a canonical model for a first-order non-Fregean logic with a connective for reference and a total truth predicate 

  Lewitzka, Steffen (2012)

  Logics with quantifiers that range over a model-theoretic universe of propositions are interesting for several applications. For example, in the context of epistemic logic the knowledge axioms can be expressed by the single ...
• TeX -Groups with few conjugacy classes of normalizers 

  Brandl, Rolf; Sica, Carmela; Tota, Maria (2013)

  For a group G , denote by ω(G) the number of conjugacy classes of normalizers of subgroups of G . Clearly, ω(G)=1 if and only if G is a Dedekind group. Hence if G is a 2-group, then G is nilpotent of class ≤2 and if G is ...
• Infinitesimal Lyapunov functions for singular flows 

  Araujo, Vitor; Salgado, Luciana (2013)

  We present an extension of the notion of infinitesimal Lyapunov function to singular flows, and from this technique we deduce a characterization of partial/sectional hyperbolic sets. In absence of singularities, we can ...
• Expanding measures 

  Pinheiro, Vilton Jeovan Viana (2011)

  We prove that any C1+αC1+α transformation, possibly with a (non-flat) critical or singular region, admits an invariant probability measure absolutely continuous with respect to any expanding measure whose Jacobian satisfies ...
• Shadowing by non-uniformly hyperbolic periodic points and uniform hyperbolicity 

  Castro, Armando; Oliveira, Krerley; Pinheiro, Vilton Jeovan Viana (2007)

  We prove that, under a mild condition on the hyperbolicity of its periodic points, a map g which is topologically conjugated to a hyperbolic map (respectively, an expanding map) is also a hyperbolic map (respectively, an ...
• Dynamic analysis of recurrent event data with missing observations, with application to infant diarrhoea in Brazil 

  Borgan, Ørnulf; Fiaccone, Rosemeire Leovigildo; Henderson, Robin; Barreto, Mauricio Lima (2007)

  This paper examines and applies methods for modelling longitudinal binary data subject to both intermittent missingness and dropout. The paper is based around the analysis of data from a study into the health impact of a ...
• New criteria for hyperbolicity based on periodic sets 

  Castro, Armando (2011)

  We prove some criteria for uniform hyperbolicity based on the periodic points of the transformation. More precisely, if a mild hyperbolicity condition holds for the periodic points of any diffeomorphism in a residual subset ...
• On Hypersurfaces of Spheres with Two Principal Curvatures 

  Costa, Ézio de Araújo; Brasil Junior, Aldir (2011)

  In this paper we obtain a classification of hypersurfaces in the Euclidean sphere having two principal curvatures; for some of the results we impose that the sectional curvature (Ricci curvature, resp.) is non-negative Ricci.
• Multidimensional Rovella-like attractors 

  Castro, A.; Pinheiro, Vilton Jeovan Viana; Araújo, V.; Pacifico, M. J. (2011)

  We present a multidimensional flow exhibiting a Rovella-like attractor: a transitive invariant set with a non-Lorenz-like singularity accumulated by regular orbits and a multidimensional non-uniformly expanding invariant ...
• Motion synthesis through 1D affine matching 

  Ferreira Júnior, Perfilino Eugênio; Torreão, José R. A.; Carvalho, Paulo Cezar Pinto; Vieira, Marcelo Bernardes (2008)

  We present the study of a data-driven motion synthesis approach based on a 1D affine image-matching equation. We start by deriving the relevant properties of the exact matching operator, such as the existence of a singular ...
• Codimension two submanifolds with 2-nonnegative curvature operator 

  Costa, Ézio de Araújo (2008)

  In this paper we obtain a classification of compact n-submanifolds of the Euclidean space Rn+2 with 2-nonnegative curvature operator.
• Geometric proprieties of invariant connections on View the MathML source 

  Fernandes, Marco Antonio Nogueira; San Martin, Luiz A. B. (2003)

  This article describes some geometric aspects of a class of affine connections in homogeneous spaces, that emerged in an earlier paper by the authors, related to the geometry of statistical models. We describe the geodesics ...
• Lyapunov exponents and rates of mixing for one-dimensional maps 

  Pinheiro, Vilton Jeovan Viana; Luzzatto, Stefano; Alves, José Ferreira (Brasil, 2004)

  We show that one-dimensional maps f with strictly positive Lyapunov exponents almost everywhere admit an absolutely continuous invariant measure. If f is topologically transitive, some power of f is mixing and, in particular, ...

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