Displaying 41 – 60 of 111

Showing per page

Error autocorrection in rational approximation and interval estimates. [A survey of results.]

Grigori Litvinov (2003)

Open Mathematics

The error autocorrection effect means that in a calculation all the intermediate errors compensate each other, so the final result is much more accurate than the intermediate results. In this case standard interval estimates (in the framework of interval analysis including the so-called a posteriori interval analysis of Yu. Matijasevich) are too pessimistic. We shall discuss a very strong form of the effect which appears in rational approximations to functions. The error autocorrection effect occurs...

Error estimates for modified local Shepard’s formulas in Sobolev spaces

Carlos Zuppa (2003)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

Interest in meshfree methods in solving boundary-value problems has grown rapidly in recent years. A meshless method that has attracted considerable interest in the community of computational mechanics is built around the idea of modified local Shepard’s partition of unity. For these kinds of applications it is fundamental to analyze the order of the approximation in the context of Sobolev spaces. In this paper, we study two different techniques for building modified local Shepard’s formulas, and...

Error estimates for Modified Local Shepard's Formulas in Sobolev spaces

Carlos Zuppa (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

Interest in meshfree methods in solving boundary-value problems has grown rapidly in recent years. A meshless method that has attracted considerable interest in the community of computational mechanics is built around the idea of modified local Shepard's partition of unity. For these kinds of applications it is fundamental to analyze the order of the approximation in the context of Sobolev spaces. In this paper, we study two different techniques for building modified local Shepard's formulas, and...

Error estimates for the finite element discretization of semi-infinite elliptic optimal control problems

Pedro Merino, Ira Neitzel, Fredi Tröltzsch (2010)

Discussiones Mathematicae, Differential Inclusions, Control and Optimization

In this paper we derive a priori error estimates for linear-quadratic elliptic optimal control problems with finite dimensional control space and state constraints in the whole domain, which can be written as semi-infinite optimization problems. Numerical experiments are conducted to ilustrate our theory.

Error estimates in the fast multipole method for scattering problems. Part 1 : truncation of the Jacobi-Anger series

Quentin Carayol, Francis Collino (2004)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

We perform a complete study of the truncation error of the Jacobi-Anger series. This series expands every plane wave e i s ^ · v in terms of spherical harmonics { Y , m ( s ^ ) } | m | . We consider the truncated series where the summation is performed over the ( , m ) ’s satisfying | m | L . We prove that if v = | v | is large enough, the truncated series gives rise to an error lower than ϵ as soon as L satisfies L + 1 2 v + C W 2 3 ( K ϵ - δ v γ ) v 1 3 where W is the Lambert function and C , K , δ , γ are pure positive constants. Numerical experiments show that this asymptotic is optimal. Those results...

Currently displaying 41 – 60 of 111