23 research outputs found
On the distribution of the maximum of a gaussian field with d parameters
Let I be a compact d-dimensional manifold, let X:I\to R be a Gaussian process
with regular paths and let F_I(u), u\in R, be the probability distribution
function of sup_{t\in I}X(t). We prove that under certain regularity and
nondegeneracy conditions, F_I is a C^1-function and satisfies a certain
implicit equation that permits to give bounds for its values and to compute its
asymptotic behavior as u\to +\infty. This is a partial extension of previous
results by the authors in the case d=1. Our methods use strongly the so-called
Rice formulae for the moments of the number of roots of an equation of the form
Z(t)=x, where Z:I\to R^d is a random field and x is a fixed point in R^d. We
also give proofs for this kind of formulae, which have their own interest
beyond the present application.Comment: Published at http://dx.doi.org/10.1214/105051604000000602 in the
Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute
of Mathematical Statistics (http://www.imstat.org
Mean number and correlation function of critical points of isotropic Gaussian fields
Let X = {X(t) : t ∈ R N } be an isotropic Gaussian random field with real values. In a first part we study the mean number of critical points of X with index k using random matrices tools. We obtain an exact expression for the probability density of the eigenvalue of rank k of a N-GOE matrix. We deduce some exact expressions for the mean number of critical points with a given index. In a second part we study attraction or repulsion between these critical points. A measure is the correlation function. We prove attraction between critical points when N > 2, neutrality for N = 2 and repulsion for N = 1. The attraction between critical points that occurs when the dimension is greater than two is due to critical points with adjacent indexes. A strong repulsion between maxima and minima is observed. The correlation function between maxima (or minima) depends on the dimension of the ambient space
Computing the Distribution of the Maximum of a Gaussian Process
This paper deals with the problem of obtaining methods to compute the distribution of the maximum of a one-parameter stochastic process on a fixed interval, mainly in the Gaussian case. The main point is the relationship between the values of the maximum and crossings of the paths, via the socalled Rice's formulae for the factorial moments of crossings. In certai
Analyse de variance non orthogonale avec GLM/SAS
SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22522, issue : a.1992 n.2 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Nonnegative Matrix Factorization with Side Information for Time Series Recovery and Prediction
Modeles de proximite inadequats Etude de validite par simulation
Available at INIST (FR), Document Supply Service, under shelf-number : 22522, issue : a.1992 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc
Proton Flux Anisotropy in the Atmosphere: Experiment and Modeling
International audienceWe used two detectors differently tilted during stratospheric balloon flights and we proved the proton flux anisotropy
Experimental Characterization of Atmospheric Radiation Environment with Stratospheric Balloon
International audienceWe report a stratospheric flight with a CNES balloon for which we developed a silicon detector in order to obtain data on the atmospheric radiation environment. The number of detected protons is shown to be directly correlated with the altitude. Simulations with the MC-ORACLE code, which uses pre-calculated fluxes with QARM, are in good agreement with our experimental results
Asymptotic expansions for the distribution of the maximum of Gaussian random fields
SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22522, issue : a.2001 n.2 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc