Robust preconditioning for coupled Stokes–Darcy problems with the Darcy problem in primal form

Constraint Preconditioning for the Coupled Stokes-Darcy System

The use of a constraint (indefinite) preconditioner for the iterative solution of the linear system arising from the finite element discretization of coupled Stokes–Darcy flow is studied. Spectral and field-of-values bounds for the preconditioned system which are independent of the underlying mesh size are presented. Numerical experiments on several twoand three-dimensional problems illustrate ...

the algorithm for solving the inverse numerical range problem

برد عددی ماتریس مربعی a را با w(a) نشان داده و به این صورت تعریف می کنیم w(a)={x8ax:x ?s1} ، که در آن s1 گوی واحد است. در سال 2009، راسل کاردن مساله برد عددی معکوس را به این صورت مطرح کرده است : برای نقطه z?w(a)، بردار x?s1 را به گونه ای می یابیم که z=x*ax، در این پایان نامه ، الگوریتمی برای حل مساله برد عددی معکوس ارانه می دهیم.

Coupled-decompositions: exploiting primal-dual interactions in convex optimization problems

Decomposition techniques implement the so-called “divide and conquer” in convex optimization problems, being primal and dual decompositions the two classical approaches. Although both solutions achieve the goal of splitting the original program into several smaller problems (called the subproblems), these techniques exhibit in general slow speed of convergence. This is a limiting factor in prac...

Fuzzy Primal Simplex Algorithms for Solving Fuzzy Linear Programming Problems

On Robust Parallel Preconditioning for Incompressible Flow Problems

We consider time-dependent flow problems discretized with higher order finite element methods. Applying a fully implicit time discretization or an IMEX scheme leads to a saddle point system. This linear system is solved using a preconditioned Krylov method, which is fully parallelized on a distributed memory parallel computer. We study a robust block-triangular preconditioner and beside numeric...