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In this paper, the generalized shift-splitting preconditioner is implemented for saddle point problems with symmetric positive definite (1,1)-block and symmetric positive semidefinite (2,2)-block. The proposed preconditioner is extracted…

Numerical Analysis · Mathematics 2015-03-03 Davod Khojasteh Salkuyeh , Mohsen Masoudi , Davod Hezari

In this paper, we describe and analyze the spectral properties of a number of exact block preconditioners for a class of double saddle point problems. Among all these, we consider an inexact version of a block triangular preconditioner…

Numerical Analysis · Mathematics 2023-07-04 Fariba Balani Bakrani , Luca Bergamaschi , Angeles Martinez , Masoud Hajarian

We present a preconditioner for saddle point problems. The proposed preconditioner is extracted from a stationary iterative method which is convergent under a mild condition. Some properties of the preconditioner as well as the eigenvalues…

Numerical Analysis · Mathematics 2016-06-23 Davod Khojasteh Salkuyeh , Mohsen Masoudi

In this article, we propose and study a stochastic and relaxed preconditioned Douglas--Rachford splitting method to solve saddle-point problems that have separable dual variables. We prove the almost sure convergence of the iteration…

Optimization and Control · Mathematics 2024-10-01 Yakun Dong , Kristian Bredies , Hongpeng Sun

We present a block lower triangular (BLT) preconditioner to accelerate the convergence of nthe Krylov subspace iterative methods, such as generalized minimal residual (GMRES), for solving a broad class of complex symmetric system of linear…

Numerical Analysis · Mathematics 2016-11-14 Davod Khojasteh Salkuyeh , Tahereh Salimi Siahkalaei

We derive an extension of the sequential homotopy method that allows for the application of inexact solvers for the linear (double) saddle-point systems arising in the local semismooth Newton method for the homotopy subproblems. For the…

Optimization and Control · Mathematics 2023-11-30 John W. Pearson , Andreas Potschka

We address the problem of preconditioning a sequence of saddle point linear systems arising in the solution of PDE-constrained optimal control problems via active-set Newton methods, with control and (regularized) state constraints. We…

Numerical Analysis · Mathematics 2015-05-25 Margherita Porcelli , Valeria Simoncini , Mattia Tani

We propose an augmented Lagrangian-based preconditioner to accelerate the convergence of Krylov subspace methods applied to linear systems of equations with a block three-by-three structure such as those arising from mixed finite element…

Numerical Analysis · Mathematics 2023-10-26 Fatemeh P. A. Beik , Michele Benzi

For 2x2 block matrices, it is well-known that block-triangular or block-LDU preconditioners with an exact Schur complement (inverse) converge in at most two iterations for fixed-point or minimal-residual methods. Similarly, for saddle-point…

Numerical Analysis · Mathematics 2020-01-06 Ben S. Southworth , Samuel A. Olivier

A modification of the generalized shift-splitting (GSS) method is presented for solving singular saddle point problems. In this kind of modification, the diagonal shift matrix is replaced by a block diagonal matrix which is symmetric…

Numerical Analysis · Mathematics 2017-04-26 Davod Khojasteh Salkuyeh , Maryam Rahimian

We propose a doubly stochastic primal-dual coordinate optimization algorithm for empirical risk minimization, which can be formulated as a bilinear saddle-point problem. In each iteration, our method randomly samples a block of coordinates…

Machine Learning · Computer Science 2017-04-13 Adams Wei Yu , Qihang Lin , Tianbao Yang

Stochastic Galerkin finite element discretizations of partial differential equations with coefficients characterized by arbitrary distributions lead, in general, to fully block dense linear systems. We propose two novel strategies for…

Numerical Analysis · Mathematics 2014-07-31 Bedřich Sousedík , Roger G. Ghanem

We study the performance of a new block preconditioner for a class of $3\times3$ block saddle point problems which arise from finite element methods for solving time-dependent Maxwell equations and some other practical problems. We also…

Numerical Analysis · Mathematics 2021-09-24 Maryam Abdolmaleki , Saeed Karimi , Davod Khojasteh Salkuyeh

It was recently demonstrated that the boundary element method based on the Burton-Miller formulation (BM-BEM), widely used for solving exterior problems, can be adapted to solve transmission problems efficiently. This approach utilises…

Numerical Analysis · Mathematics 2025-06-03 Keigo Tomoyasu , Hiroshi Isakari

The Virtual Element Method (VEM) is a new family of numerical methods for the approximation of partial differential equations, where the geometry of the polytopal mesh elements can be very general. The aim of this article is to extend the…

Numerical Analysis · Mathematics 2022-07-05 Tommaso Bevilacqua , Simone Scacchi

This paper proposes a new preconditioning scheme for a linear system with a saddle-point structure arising from a hybrid approximation scheme on the sphere, an approximation scheme that combines (local) spherical radial basis functions and…

Numerical Analysis · Mathematics 2010-09-23 Q. T. Le Gia , Ian H. Sloan , Andrew J. Wathen

In this paper, we execute the shift-splitting preconditioner for asymmetric saddle point problems with its (1,2) block's transposition unequal to its (2,1) block under the removed minus of its (2,1) block. The proposed preconditioner is…

Numerical Analysis · Mathematics 2021-09-13 Shi-Liang Wu , Davod Khojasteh Salkuyeh

We present a simple way to discretize and precondition mixed variational formulations. Our theory connects with, and takes advantage of, the classical theory of symmetric saddle point problems and the theory of preconditioning symmetric…

Numerical Analysis · Mathematics 2018-05-18 Constantin Bacuta , Jacob Jacavage

In this paper, a fast solver is studied for saddle point system arising from a second-order Crank-Nicolson discretization of an initial-valued parabolic PDE constrained optimal control problem, which is indefinite and ill-conditioned.…

Numerical Analysis · Mathematics 2023-12-21 Xue-Lei Lin , Shu-Lin Wu

We introduce a preconditioner based on a hierarchical low-rank compression scheme of Schur complements. The construction is inspired by standard nested dissection, and relies on the assumption that the Schur complements can be approximated,…

Numerical Analysis · Mathematics 2015-09-01 Paolo Gatto , Jan S. Hesthaven