Optimal convergence rates for inexact Newton regularization with CG as inner iteration

2020 ◽  
Vol 28 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Andreas Neubauer

AbstractIn this paper we prove order optimality of an inexact Newton regularization method, where the linearized equations are solved approximately using the conjugate gradient method. The outer and inner iterations are stopped via the discrepancy principle. We show that the conditions needed for convergence rates are satisfied for a certain parameter identification problem.

2020 ◽  
Vol 28 (2) ◽  
pp. 251-273
Author(s):  
Subhankar Mondal ◽  
M. Thamban Nair

AbstractRecently, Nair and Roy (2017) considered a linear regularization method for a parameter identification problem in an elliptic PDE. In this paper, we consider similar procedure for identifying the diffusion coefficient in the heat equation, modifying the Sobolev spaces involved appropriately. We derive error estimates under appropriate conditions and also consider the finite-dimensional realization of the method, which is essential for practical application. In the analysis of finite-dimensional realization, we give a procedure to obtain finite-dimensional subspaces of an infinite-dimensional Hilbert space {L^{2}(0,T;H^{1}(\Omega))} by doing double discretization, that is, discretization corresponding to both the space and time domain. Also, we analyze the parameter choice strategy and obtain an a posteriori parameter which is order optimal.


2019 ◽  
Vol 23 (Suppl. 2) ◽  
pp. 575-582 ◽  
Author(s):  
Evgenii Kuznetsov ◽  
Sergey Leonov ◽  
Dmitry Tarkhov ◽  
Alexander Vasilyev

The paper deals with a parameter identification problem for creep and fracture model. The system of ordinary differential equations of kinetic creep theory is applied for describing this model. As for solving the parameter identification problem, we proposed to use the technique of neural network modeling, as well as the multilayer approach. The procedures of neural network modeling and multilayer approximation constructing application is demonstrated by the example of finding parameters for uniaxial tension model for isotropic steel 45 specimens at creep conditions. The solution corresponding to the obtained parameters agrees well with theoretical strain-damage characteristics, experimental data, and results of other authors.


1992 ◽  
Vol 66 (4) ◽  
pp. 307-318 ◽  
Author(s):  
John A. White ◽  
Paul B. Manis ◽  
Eric D. Young

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