Results 261 to 270 of about 988,939 (305)

Ill-Posed Problems

2013
As previously mentioned, for problems in mathematical physics Hadamard [95] postulated three requirements: a solution should exist, the solution should be unique, and the solution should depend continuously on the data. The third postulate is motivated by the fact that in all applications the data will be measured quantities.
Fioralba Cakoni, David Colton
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AN ILL-POSED PROBLEM FOR THE HEAT EQUATION

Mathematical Models and Methods in Applied Sciences, 2009
The Cauchy problem for the heat equation in which Cauchy data are prescribed on the outer boundary of a domain with cavity and no data are given on the inner boundary is known to be ill-posed. By a slight modification of the boundary conditions a new problem is introduced whose solution depends continuously on the data in L2.
Payne, L. E., Philippin, G. A.
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Stochastic Methods for Ill-Posed Problems

BIT Numerical Mathematics, 2000
This paper considers the behaviour of ill-posed problems of the stochastic Euler method, semi-implicit Euler method and some new method. The new method shows improved stability for stiff problems. It has been shown that the applied regularization cannot be driven beyond a certain critical parameter level.
Burrage, K., Piskarev, S.
openaire   +5 more sources

Inverse and Ill-Posed Problems $$\star $$

2018
When we evaluate the expression \({{\varvec{f}}} = A{{\varvec{u}}}\), where \({{\varvec{u}}}\) and \({{\varvec{f}}}\) are vectors and A is a matrix, we solve a direct or forward problem. Given A we can precisely calculate \({{\varvec{f}}}\) for any \({{\varvec{u}}}\).
Simon Širca, Martin Horvat
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Ill-posed problems

1987
This section is devoted to a preliminary discussion of the stability problem. We shall give a definition of ill-posed problems and sketch the main idea to restore stability in ill-
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Regularization of Discrete Ill-Posed Problems

BIT Numerical Mathematics, 2004
Discrete approximations \( A_n u_n = f_n \) of an ill-posed equation (1) \( Au = f \) with a linear compact operator \( A: X \to X \) in a Hilbert space \( X \) are considered. Here, \( A_n: X_n \to X_n \) is a linear bounded operator in a finite-dimensional Hilbert space \( X_n \), where \( \{X_n,r_n,p_n\} \) is a convergent and stable discrete ...
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Optimal discretization of Ill-posed problems

Ukrainian Mathematical Journal, 2000
Summary: We present a review of results obtained in the Institute of Mathematics of National Ukrainian Academy of Sciences when investigating the optimal digitization of ill-posed problems.
Pereverzev, S. V., Solodkij, S. G.
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Solutions of Ill-Posed Linear Equations

2013
Linear system of equations is been used more and more widely in social life. Most people use the estimated value for a variety of computing that will cause a lot of errors. Familiar with a variety of ill-posed linear equations solution can make us grasp the algorithm and make the error reduce to the minimum in practice, thereby increasing the accuracy ...
Yamian Peng, Jincai Chang, Yan Yan
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Ill-Posed Problems

1983
Problems involving differential equations usually come in the following form: we are given an equation for the unknown function u, P(u) = f, on a domain Ω together with some “side” conditions on u. For example, we may require that u assumes certain preassigned values on ∂Ω, or that u is in L 2(Ω), or that u is in class C k in Ω.
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A descent method for regularization of ill-posed problems

Optimization Methods and Software, 2005
In this paper, we describe an iterative algorithm, called descent-TCG, based on truncated conjugate gradients iterations to compute Tikhonov regularized solutions of linear ill-posed problems. The sequence of approximate solutions and regularization parameters, computed by the algorithm, is shown to decrease the value of the Tikhonov functional ...
ZAMA, FABIANA, LOLI PICCOLOMINI, ELENA
openaire   +3 more sources