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Data approximation using polyharmonic radial basis functions

Segeth, Karel (2021)

Programs and Algorithms of Numerical Mathematics

The paper is concerned with the approximation and interpolation employing polyharmonic splines in multivariate problems. The properties of approximants and interpolants based on these radial basis functions are shown. The methods of such data fitting are applied in practice to treat the problems of, e.g., geographic information systems, signal processing, etc. A simple 1D computational example is presented.

Data assimilation for the time-dependent transport problem

Victor Shutyaev (2000)

Banach Center Publications

In this paper we consider the data assimilation problem for a timedependent transport problem in a slab when the initial condition is not known. The spaces of traces are introduced, the solvability of the original initial-boundary value transport problem is studied. The properties of the control operator are investigated, the solvability of the data assimilation problem is proved. The class of iterative methods for solving the problem is considered, and the convergence conditions are studied. The...

Data compression with Σ Π -approximations based on splines

Olga E. Baklanova, Vladimir A Vasilenko (1993)

Applications of Mathematics

The paper contains short description of Σ Π -algorithm for the approximation of the function with two independent variables by the sum of products of one-dimensional functions. Some realizations of this algorithm based on the continuous and discrete splines are presented here. Few examples concerning with compression in the solving of approximation problems and colour image processing are described and discussed.

Daubechies wavelets on intervals with application to BVPs

Václav Finěk (2004)

Applications of Mathematics

In this paper, Daubechies wavelets on intervals are investigated. An analytic technique for evaluating various types of integrals containing the scaling functions is proposed; they are compared with classical techniques. Finally, these results are applied to two-point boundary value problems.

De Lambert à Cauchy : la résolution des équations littérales par le moyen des séries

Jean-Pierre Lubet (1998)

Revue d'histoire des mathématiques

En 1770, Lagrange démontre la formule qui porte son nom et qui donne, sous forme de série, l’expression de la racine d’une équation algébrique ou transcendante. La formule elle-même et la méthode de démonstration sont significatives du style et de la pensée de l’auteur de la Théorie des fonctions analytiques. De nombreuses études sont consacrées ensuite à ce théorème de Lagrange par d’autres mathématiciens. Elles portent la trace de préoccupations ou d’exigences particulières à leurs auteurs. Elles...

Decentralized control and synchronization of time-varying complex dynamical network

Wei-Song Zhong, Jovan D. Stefanovski, Georgi M. Dimirovski, Jun Zhao (2009)

Kybernetika

A new class of controlled time-varying complex dynamical networks with similarity is investigated and a decentralized holographic-structure controller is designed to stabilize the network asymptotically at its equilibrium states. The control design is based on the similarity assumption for isolated node dynamics and the topological structure of the overall network. Network synchronization problems, both locally and globally, are considered on the ground of decentralized control approach. Each sub-controller...

Decomposition of an updated correlation matrix via hyperbolic transformations

Drahoslava Janovská (2002)

Applications of Mathematics

An algorithm for hyperbolic singular value decomposition of a given complex matrix based on hyperbolic Householder and Givens transformation matrices is described in detail. The main application of this algorithm is the decomposition of an updated correlation matrix.

Defect correction and a posteriori error estimation of Petrov-Galerkin methods for nonlinear Volterra integro-differential equations

Shu Hua Zhang, Tao Lin, Yan Ping Lin, Ming Rao (2000)

Applications of Mathematics

We present two defect correction schemes to accelerate the Petrov-Galerkin finite element methods [19] for nonlinear Volterra integro-differential equations. Using asymptotic expansions of the errors, we show that the defect correction schemes can yield higher order approximations to either the exact solution or its derivative. One of these schemes even does not impose any extra regularity requirement on the exact solution. As by-products, all of these higher order numerical methods can also be...

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