Results 201 to 210 of about 23,573 (262)

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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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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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.
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Noise Models for Ill-Posed Problems

2010
The standard view of noise in ill-posed problems is that it is either deterministic and small (strongly bounded noise) or random and large (not necessarily small). Following Eggerment, LaRiccia and Nashed (2009), a new noise model is investigated, wherein the noise is weakly bounded.
Eggermont, Paul N., LaRiccia, Vincent, Nashed, M. Zuhair   +2 more
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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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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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On a Monotone Ill–posed Problem

Acta Mathematica Sinica, English Series, 2005
Let \(X\) be a real reflexive Banach space with dual \(X^*\). Let \(A:X \rightarrow X^*\) be a nonlinear continuous monotone operator. In general, the equation \(Ax=f, \;f\in R(A)\), is ill-posed, i.e., its solutions do not depend continuously on \(f\).
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Ill-Posed Problem Instances

1993
This chapter consists of those sections of a longer work [5] which formed the basis for much of the author’s talk at the Smalefest. The longer work contains complete proofs and develops much additional material.
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