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Dragi Anevski - One of the best experts on this subject based on the ideXlab platform.

  • Limit properties of the monotone rearrangement for density and regression function estimation
    Bernoulli, 2019
    Co-Authors: Dragi Anevski, Anne-laure Fougères
    Abstract:

    The monotone rearrrangement algorithm was introduced by Hardy, Littlewood and Pólya as a sorting device for functions. Assuming that x is a monotone function and that an estimate x n of x is given, consider the monotone rearrangementˆxrearrangementˆ rearrangementˆx n of x n. This new estimator is shown to be uniformly consistent as soon as x n is. Under suitable assumptions, Pointwise Limit distribution results forˆxforˆ forˆx n are obtained. The framework is general and allows for weakly dependent and long range dependent stationary data. Applications in monotone density and regression function estimation are detailed. Asymptotics for rearrangement estimators with vanishing derivatives are also obtained in these two contexts.

  • Monotone spectral density estimation
    Annals of Statistics, 2011
    Co-Authors: Dragi Anevski, Philippe Soulier
    Abstract:

    We propose two estimators of a unimodal or monotone spectral density, that are based on the periodogram. These are the isotonic regression of the periodogram and the isotonic regression of the log-periodogram. We derive Pointwise Limit distribution results for the proposed estimators for short memory linear processes and long memory Gaussian processes and also that the estimators are rate optimal.

  • Limit properties of the monotone rearrangement for density and regression function estimation
    2008
    Co-Authors: Dragi Anevski, Anne-laure Fougères
    Abstract:

    The monotone rearrrangement algorithm was introduced by Hardy, Littlewood and Po lya as a sorting device for functions. As- suming that x is a monotone function and that an estimate xn of x is given, consider the monotone rearrangement xˆn of xn. This new estimator is shown to be uniformly consistent. Under suitable as- sumptions, Pointwise Limit distribution results for xˆn are obtained. The framework is general and allows for weakly dependent and long range dependent stationary data. Applications in monotone density and regression function estimation are detailed.

  • A general asymptotic scheme for inference under order restrictions
    The Annals of Statistics, 2006
    Co-Authors: Dragi Anevski, Ola Hossjer
    Abstract:

    Limit distributions for the greatest convex minorant and its derivative are considered for a general class of stochastic processes including partial sum processes and empirical processes, for independent, weakly dependent and long range dependent data. The results are applied to isotonic regression, isotonic regression after kernel smoothing, estimation of convex regression functions, and estimation of monotone and convex density functions. Various Pointwise Limit distributions are obtained, and the rate of convergence depends on the self similarity properties and on the rate of convergence of the processes considered.

  • monotone regression and density function estimation at a point of discontinuity
    Journal of Nonparametric Statistics, 2002
    Co-Authors: Dragi Anevski, Ola Hossjer
    Abstract:

    Pointwise Limit distribution results are given for the isotonic regression estimator at a point of discontinuity. The cases treated are independent data, - and f -mixing data and subordinated Gaussian long range dependent data. Pointwise Limit results for the nonparametric maximum likelihood estimator of a monotone density are given at a point of discontinuity, for independent data. The Limit distributions are non-standard and differ from the ones obtained for differentiable regression and density functions.

Sandro Levi - One of the best experts on this subject based on the ideXlab platform.

  • strong uniform continuity
    Journal of Mathematical Analysis and Applications, 2009
    Co-Authors: Gerald Beer, Sandro Levi
    Abstract:

    Abstract Let B be an ideal of subsets of a metric space 〈 X , d 〉 . This paper considers a strengthening of the notion of uniform continuity of a function restricted to members of B which reduces to ordinary continuity when B consists of the finite subsets of X and agrees with uniform continuity on members of B when B is either the power set of X or the family of compact subsets of X. The paper also presents new function space topologies that are well suited to this strengthening. As a consequence of the general theory, we display necessary and sufficient conditions for continuity of the Pointwise Limit of a net of continuous functions.

Hikmet Koyunbakan - One of the best experts on this subject based on the ideXlab platform.

Irene M. Gamba - One of the best experts on this subject based on the ideXlab platform.

  • Viscosity Approximating Solutions to ODE Systems That Admit Shocks, and Their Limits
    Advances in Applied Mathematics, 1994
    Co-Authors: Irene M. Gamba
    Abstract:

    We study nonlinear systems of ordinary differential equations that arise when considering stationary one-dimensional systems of conservation laws with forcing terms defined in a bounded interval. We construct weak entropy solutions of bounded variation which are Pointwise and L^1 Limits of solutions of regularized, i.e., viscous, systems, where the Limit is taken in the viscosity parameter. In particular, no oscillations occur either for the viscous solutions or for the inviscid one. We also discuss the possible formation of boundary layers when boundary values are prescribed for the viscous regularized equations. As applications, first we show the existence of transonic solutions of bounded variation with strong shocks for the equation of stationary gas flow in a duct of variable area as a Pointwise Limit of artificial viscosity solutions. We analyze their properties depending on the kind of duct as well as on the boundary data of the regularized problem. Second we show that the model applies to the hydrodynamic modeling for semiconductor devices for some particular heat conduction terms and added diffusion to the energy equation. In particular, we show that under the assumption of bounds for the state variables, there exists a regular solution for that particular viscous heat conducting model. Also, if the bounds for the state variables are uniform in the vanishing parameters, we obtain the existence of an inviscid weak entropy solution of bounded variation as a Pointwise Limit of the regular ones.

Ola Hossjer - One of the best experts on this subject based on the ideXlab platform.

  • A general asymptotic scheme for inference under order restrictions
    The Annals of Statistics, 2006
    Co-Authors: Dragi Anevski, Ola Hossjer
    Abstract:

    Limit distributions for the greatest convex minorant and its derivative are considered for a general class of stochastic processes including partial sum processes and empirical processes, for independent, weakly dependent and long range dependent data. The results are applied to isotonic regression, isotonic regression after kernel smoothing, estimation of convex regression functions, and estimation of monotone and convex density functions. Various Pointwise Limit distributions are obtained, and the rate of convergence depends on the self similarity properties and on the rate of convergence of the processes considered.

  • monotone regression and density function estimation at a point of discontinuity
    Journal of Nonparametric Statistics, 2002
    Co-Authors: Dragi Anevski, Ola Hossjer
    Abstract:

    Pointwise Limit distribution results are given for the isotonic regression estimator at a point of discontinuity. The cases treated are independent data, - and f -mixing data and subordinated Gaussian long range dependent data. Pointwise Limit results for the nonparametric maximum likelihood estimator of a monotone density are given at a point of discontinuity, for independent data. The Limit distributions are non-standard and differ from the ones obtained for differentiable regression and density functions.