scholarly journals A Greedy Strategy for Coarse-Grid Selection

2007 ◽  
Vol 29 (5) ◽  
pp. 1825-1853 ◽  
Author(s):  
S. MacLachlan ◽  
Yousef Saad
Keyword(s):  
Coarse Grid ◽  
Greedy Strategy ◽  
Grid Selection

scholarly journals Coarse-grid selection for parallel algebraic multigrid

1998 ◽  
pp. 104-115 ◽  
Author(s):  
Andrew J. Cleary ◽  
Robert D. Falgout ◽  
Van Emden Henson ◽  
Jim E. Jones
Keyword(s):  
Coarse Grid ◽  
Algebraic Multigrid ◽  
Selection For ◽  
Grid Selection

Parallel coarse-grid selection

2007 ◽  
Vol 14 (8) ◽  
pp. 611-643 ◽  
Author(s):  
David M. Alber ◽  
Luke N. Olson
Keyword(s):  
Coarse Grid ◽  
Grid Selection

scholarly journals Search for a moving target in a competitive environment

2021 ◽  
Author(s):  
Benoit Duvocelle ◽  
János Flesch ◽  
Hui Min Shi ◽  
Dries Vermeulen
Keyword(s):  
Markov Chain ◽  
Discrete Time ◽  
Competitive Environment ◽  
Moving Target ◽  
Time Varying ◽  
Greedy Strategy ◽  
Time Dynamic ◽  
Dynamic Search ◽  
Subgame Perfect Equilibria ◽  
Perfect Equilibria

AbstractWe consider a discrete-time dynamic search game in which a number of players compete to find an invisible object that is moving according to a time-varying Markov chain. We examine the subgame perfect equilibria of these games. The main result of the paper is that the set of subgame perfect equilibria is exactly the set of greedy strategy profiles, i.e. those strategy profiles in which the players always choose an action that maximizes their probability of immediately finding the object. We discuss various variations and extensions of the model.

Exploitation of coarse grid for electromagnetic optimization

2002 ◽  
Author(s):  
J.W. Bandler ◽  
R.M. Biernacki ◽  
S.H. Chen ◽  
P.A. Grobelny ◽  
R.H. Hemmers
Keyword(s):  
Coarse Grid

scholarly journals Flow Simulation Using Local Grid Refinements to Model Laminated Reservoirs

2018 ◽  
Vol 73 ◽  
pp. 5 ◽  
Author(s):  
Manuel Gomes Correia ◽  
Célio Maschio ◽  
Denis José Schiozer
Keyword(s):  
Simulation Model ◽  
Dynamic Properties ◽  
Flow Behavior ◽  
Flow Simulation ◽  
Coarse Grid ◽  
Thin Layers ◽  
Static Properties ◽  
Dynamic Representation ◽  
Medium Flow ◽  
Local Grid

Super-giant carbonate fields, such as Ghawar, in Saudi Arabia, and Lula, at the Brazilian pre-salt, show highly heterogeneous behavior that is linked to high permeability intervals in thin layers. This article applies Local Grid Refinements (LGR) integrated with upscaling procedures to improve the representation of highly laminated reservoirs in flow simulation by preserving the static properties and dynamic trends from geological model. This work was developed in five main steps: (1) define a conventional coarse grid, (2) define LGR in the conventional coarse grid according to super-k and well locations, (3) apply an upscaling procedure for all scenarios, (4) define LGR directly in the simulation model, without integrate geological trends in LGR and (5) compare the dynamic response for all cases. To check results and compare upscaling matches, was used the benchmark model UNISIM-II-R, a refined model based on a combination of Brazilian Pre-salt and Ghawar field information. The main results show that the upscaling of geological models for coarse grid with LGR in highly permeable thin layers provides a close dynamic representation of geological characterization compared to conventional coarse grid and LGR only near-wells. Pseudo-relative permeability curves should be considered for (a) conventional coarse grid or (b) LGR scenarios under dual-medium flow simulations as the upscaling of discrete fracture networks and dual-medium flow models presents several limitations. The conventional approach of LGR directly in simulation model, presents worse results than LGR integrated with upscaling procedures as the extrapolation of dynamic properties to the coarse block mismatch the dynamic behavior from geological characterization. This work suggests further improvements for results for upscaling procedures that mask the flow behavior in highly laminated reservoirs.

A Combined Global Coarsening Method for 3D Multigrid Applications

2012 ◽  
Vol 236-237 ◽  
pp. 1049-1053
Author(s):  
Zong Zhe Li ◽  
Zheng Hua Wang ◽  
Lu Yao ◽  
Wei Cao
Keyword(s):  
Aspect Ratio ◽  
Present Method ◽  
Unstructured Grid ◽  
Unstructured Grids ◽  
Coarse Grid ◽  
3D Flow ◽  
High Quality ◽  
Coarse Grids

An automatic agglomeration methodology to generate coarse grids for 3D flow solutions on anisotropic unstructured grids has been introduced in this paper. The algorithm combines isotropic octree based coarsening and anisotropic directional agglomeration to yield a desired coarsening ratio and high quality of coarse grids, which developed for cell-centered multigrid applications. This coarsening strategy developed is presented on an unstructured grid over 3D ONERA M6 wing. It is shown that the present method provides suitable coarsening ratio and well defined aspect ratio cells at all coarse grid levels.

About the efficiency of grid selection

Euphytica ◽  
1983 ◽  
Vol 32 (3) ◽  
pp. 885-893 ◽  
Author(s):  
I. Bos
Keyword(s):  
Grid Selection
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