Search Results - subject:"Multigrid"

Using inexact gradients in a multilevel optimization algorithm

Lewis, Robert; Nash, Stephen - In: Computational Optimization and Applications 56 (2013) 1, pp. 39-61

Many optimization algorithms require gradients of the model functions, but computing accurate gradients can be computationally expensive. We study the implications of using inexact gradients in the context of the multilevel optimization algorithm <Emphasis Type="SmallCaps">MG/Opt. <Emphasis Type="SmallCaps">MG/Opt recursively uses (typically...</emphasis></emphasis>

Persistent link: https://www.econbiz.de/10010998282

A practically unconditionally gradient stable scheme for the N-component Cahn–Hilliard system

Lee, Hyun Geun; Choi, Jeong-Whan; Kim, Junseok - In: Physica A: Statistical Mechanics and its Applications 391 (2012) 4, pp. 1009-1019

method and is solved by an efficient and accurate nonlinear multigrid method. The scheme allows us to convert the N …

Persistent link: https://www.econbiz.de/10011058928

Multigrid second-order accurate solution of parabolic control-constrained problems

Andrade, S. González; Borzì, A. - In: Computational Optimization and Applications 51 (2012) 2, pp. 835-866

Persistent link: https://www.econbiz.de/10010998289

A smooth penalty approach and a nonlinear multigrid algorithm for elliptic MPECs

Hintermüller, M.; Kopacka, I. - In: Computational Optimization and Applications 50 (2011) 1, pp. 111-145

Persistent link: https://www.econbiz.de/10009325284

Study of multiscale global optimization based on parameter space partition

Sun, Weitao; Dong, Yuan - In: Journal of Global Optimization 49 (2011) 1, pp. 149-172

Persistent link: https://www.econbiz.de/10008775637

A multigrid solver for phase field simulation of microstructure evolution

Vanherpe, Liesbeth; Wendler, Frank; Nestler, Britta; … - In: Mathematics and Computers in Simulation (MATCOM) 80 (2010) 7, pp. 1438-1448

nonlinear multigrid solver based on the Full Approximation Scheme is implemented to solve the equations resulting from this … discretisation. Simulations with the multigrid solver show that the solver has grid size independent convergence properties and is … faster than a standard first-order explicit solver. As such, the multigrid solver promises to be a reliable additional …

Persistent link: https://www.econbiz.de/10010870306

An efficient multigrid preconditioner for Maxwell’s equations in micromagnetism

Baňas, Ľubomír - In: Mathematics and Computers in Simulation (MATCOM) 80 (2010) 8, pp. 1657-1663

micromagnetism. The problem is discretized by a convergent, unconditionally stable finite element method. A multigrid preconditioned …

Persistent link: https://www.econbiz.de/10011050530

An unconditionally gradient stable numerical method for solving the Allen–Cahn equation

Choi, Jeong-Whan; Lee, Hyun Geun; Jeong, Darae; Kim, Junseok - In: Physica A: Statistical Mechanics and its Applications 388 (2009) 9, pp. 1791-1803

We consider an unconditionally gradient stable scheme for solving the Allen–Cahn equation representing a model for anti-phase domain coarsening in a binary mixture. The continuous problem has a decreasing total energy. We show the same property for the corresponding discrete problem by using...

Persistent link: https://www.econbiz.de/10010588742

Experiment and multi-grid modeling of evacuation from a classroom

Zhang, Jun; Song, Weiguo; Xu, Xuan - In: Physica A: Statistical Mechanics and its Applications 387 (2008) 23, pp. 5901-5909

variable velocity, dislocable queuing, monopolizing exit and so on. Based on the experimental observation, we improve the multi-grid …. With the improved multi-grid model, we simulate the evacuation process and compare the simulation results with the …

Persistent link: https://www.econbiz.de/10010872122

Discretization effect in a multi-grid egress model

Xu, X.; Song, W.G.; Zheng, H.Y. - In: Physica A: Statistical Mechanics and its Applications 387 (2008) 22, pp. 5567-5574

evacuation results, we studied the evacuation process using a multi-grid egress model. In the multi-grid model, a finer grid is … complex changes. The differences between the single-grid model and multi-grid model may be due to two main reasons. First, in … the multi-grid model, the pedestrians are out of alignment so that there are patches of unusable empty spaces as they are …

Persistent link: https://www.econbiz.de/10011059547