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Tang, J.M. (author), Nabben, R. (author), Vuik, C. (author), Erlangga, Y.A. (author)For various applications, it is well-known that a multi-level, in particular two-level, preconditioned CG (PCG) method is an efficient method for solving large and sparse linear systems with a coefficient matrix that is symmetric positive definite. The corresponding two-level preconditioner combines traditional and projection-type...journal article 2009
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- Tang, J.M. (author), Nabben, R. (author), Vuik, C. (author), Erlangga, Y.A. (author) report 2007
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Riyanti, C.D. (author), Erlangga, Y.A. (author), Plessix, R.E. (author), Mulder, W.A. (author), Vuik, C. (author), Oosterlee, C. (author)The time-harmonic wave equation, also known as the Helmholtz equation, is obtained if the constant-density acoustic wave equation is transformed from the time domain to the frequency domain. Its discretization results in a large, sparse, linear system of equations. In two dimensions, this system can be solved efficiently by a direct method. In...journal article 2006
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van Gijzen, M.B. (author), Erlangga, Y.A. (author), Vuik, C. (author)Shifted Laplace preconditioners have attracted considerable attention as a technique to speed up convergence of iterative solution methods for the Helmholtz equation. In this paper we present a comprehensive spectral analysis of the Helmholtz operator preconditioned with a shifted Laplacian. Our analysis is valid under general conditions. The...report 2006
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Erlangga, Y.A. (author), Oosterlee, C.W. (author), Vuik, C. (author)An iterative solution method, in the form of a preconditioner for a Krylov subspace method, is presented for the Helmholtz equation. The preconditioner is based on a Helmholtz type differential operator with a complex term. A multigrid iteration is used for approximately inverting the preconditioner. The choice of multigrid components for the...report 2004
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- Vuik, C. (author), Erlangga, Y.A., Oosterlee, C.W. (author) report 2003
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- Erlangga, Y.A. (author), Vuik, C. (author), Oosterlee, C.W. (author) report 2003