Browsing Τμήμα Μαθηματικών και Στατιστικής / Department of Mathematics and Statistics by Submit Date
Now showing items 120 of 1528

Article
A comparative simulation study of wavelet shrinkage estimators for Poisson counts
(2004)Using computer simulations, the finite sample performance of a number of classical and Bayesian wavelet shrinkage estimators for Poisson counts is examined. For the purpose of comparison, a variety of intensity functions, ...

Article
Subsampling continuous parameter random fields and a Bernstein inequality
(2000)In the present paper we study the subsampling methodology for approximating the distribution of statistics estimating some unknown parameter associated with the probability distribution of a continuous parameter random ...

Article
On Subsampling Estimators with Unknown Rate of Convergence
(1999)Politis and Romano have put forth a general subsampling methodology for the construction of largesample confidence regions for a general unknown parameter θ associated with the probability distribution generating the ...

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Extrapolation of subsampling distribution estimators: The i.i.d. and strong mixing cases
(2001)Politis & Romano (1994) proposed a general subsampling methodology for the construction of largesample confidence regions for an arbitrary parameter under minimal conditions. Nevertheless, the subsampling distribution ...

Article
A Legendre spectral quadrature Galerkin method for the CauchyNavier equations of elasticity with variable coefficients
(2017)We solve the Dirichlet and mixed DirichletNeumann boundary value problems for the variable coefficient CauchyNavier equations of elasticity in a square using a Legendre spectral Galerkin method. The resulting linear ...

Article
Spectral Chebyshev collocation for the poisson and biharmonic equations
(2010)This paper is concerned with the spectral Chebyshev collocation solution of the Dirichlet problems for the Poisson and biharmonic equations in a square. The collocation schemes are solved at a cost of 2N3 + O(N2 logN) ...

Article
Modified nodal cubic spline collocation for threedimensional variable coefficient second order partial differential equations
(2013)We formulate a fourth order modified nodal cubic spline collocation scheme for variable coefficient second order partial differential equations in the unit cube subject to nonzero Dirichlet boundary conditions. The approximate ...

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Finite Difference Schemes for the Cauchy–Navier Equations of Elasticity with Variable Coefficients
(2015)We solve the variable coefficient Cauchy–Navier equations of elasticity in the unit square, for Dirichlet and DirichletNeumann boundary conditions, using second order finite difference schemes. The resulting linear systems ...

Article
Moderate deviations in subsampling distribution estimation
(2001)In Politis and Romano (1994) the subsampling methodology was put forth for approximating the sampling distribution (and the corresponding quantiles) of general statistics from i.i.d. and stationary data. In this note, we ...

Article
Subsampling the distribution of diverging statistics with applications to finance
(2004)In this paper we propose a subsampling estimator for the distribution of statistics diverging at either known or unknown rates when the underlying time series is strictly stationary and strong mixing. Based on our results ...

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Spectral ChebyshevFourier collocation for the Helmholtz and variable coefficient equations in a disk
(2008)The paper is concerned with the spectral collocation solution of the Helmholtz equation in a disk in the polar coordinates r and θ. We use spectral Chebyshev collocation in r, spectral Fourier collocation in θ, and a simple ...

Article
A nonoverlapping domain decomposition method for Legendre spectral collocation problems
(2007)We consider the Dirichlet boundary value problem for Poisson's equation in an Lshaped region or a rectangle with a crosspoint. In both cases, we approximate the Dirichlet problem using Legendre spectral collocation, that ...

Article
Optimal superconvergent one step quadratic spline collocation methods
(2008)We formulate new optimal quadratic spline collocation methods for the solution of various elliptic boundary value problems in the unit square. These methods are constructed so that the collocation equations can be solved ...

Article
Matrix decomposition algorithms for modified spline collocation for Helmholtz problems
(2003)We consider the solution of various boundary value problems for the Helmholtz equation in the unit square using a nodal cubic spline collocation method and modifications of it which produce optimal (fourth) order ...

Article
Legendre Gauss spectral collocation for the Helmholtz equation on a rectangle
(2004)A spectral collocation method with collocation at the Legendre Gauss points is discussed for solving the Helmholtz equation Δu+κ(x,y)u=f(x,y) on a rectangle with the solution u subject to inhomogeneous Robin boundary ...

Article
A Legendre spectral Galerkin method for the biharmonic Dirichlet problem
(2001)A Legendre spectral Galerkin method is presented for the solution of the biharmonic Dirichlet problem on a square. The solution and its Laplacian are approximated using the set of basis functions suggested by Shen, which ...

Article
Minimax rates of convergence and optimality of bayes factor wavelet regression estimators under pointwise risks
(2009)We consider function estimation in nonparametric regression over Besov spaces and under pointwise lurisks (1 ≤ u < ∞). First we derive both nonadaptive and adaptive minimax pointwise rates of convergence in the standard ...

Article
A legendre spectral collocation method for the biharmonic Dirichlet problem
(2000)A Legendre spectral collocation method is presented for the solution of the biharmonic Dirichlet problem on a square. The solution and its Laplacian are approximated using the set of basis functions suggested by Shen, which ...