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Segmental Refinement: A Multigrid Technique for Data Locality

Mark F. Adams, Jed Brown, Matt Knepley, Ravi Samtaney
2016 SIAM Journal on Scientific Computing  
We investigate a domain decomposed multigrid technique, segmental refinement, for solving general nonlinear elliptic boundary value problems.  ...  We present a communication complexity analysis that quantifies the communication costs ameliorated by segmental refinement and report performance results with up to 64K cores of a Cray XC30.  ...  We would like to thank Achi Brandt for his generous guidance in developing these algorithms. This material is based upon work supported by the U.  ... 
doi:10.1137/140975127 fatcat:256xgrubnbbgfbskftytraro2a

A PRIORI LOCAL GRID REFINEMENT IN THE MULTIGRID METHOD [chapter]

Joel E. Dendy
1984 Elliptic Problem Solvers  
e"l w .9", JW a", k.femn, . M,.," m ,., XIII, mm-cl,! ,rti", twocm, or w!.fce b, ,rd. rum, ,rnd"m'wk M9"uI, <,u(0,. 0, o,!  ...  ., r',a, -,1" CO""I,"I. w ,nml" I" ,c.kwmwn" recmmwrwy", o", or Iav.ar,rq b, ", Un"ed Stats! GOwmmmt o! ."" m" thoroc.f, Tha .mv.l qa w,.,.", .1 .utho" .xP,W $".1" do c+, -11" "", C9 ,et!  ...  Hyman (6) may solve this difficulty, in which case the above multigrid local mesh refinement techniques --re~ixing a logically rectangular structure--may be ujed.  ... 
doi:10.1016/b978-0-12-100560-3.50034-2 fatcat:rj3mbdsyifhjjiwsm3cvqnej44

Interactive Multigrid Refinement for Deformable Image Registration

Wu Zhou, Yaoqin Xie
2013 BioMed Research International  
We can manually revise the transformed image locally in a hierarchical multigrid manner to make the transformed image register well with the reference image.  ...  The resulting deformation controls the shape of the transformed image and produces a nice registration or improves the registration results of other registration methods.  ...  The Framework of Interactive Multigrid Refinement Algorithm.  ... 
doi:10.1155/2013/532936 pmid:24232828 pmcid:PMC3819831 fatcat:huavmpwcb5d4npoxnivkcv7zi4

Adaptive Mesh Refinement and Adaptive Time Integration for Electrical Wave Propagation on the Purkinje System

Wenjun Ying, Craig S. Henriquez
2015 BioMed Research International  
A both space and time adaptive algorithm is presented for simulating electrical wave propagation in the Purkinje system of the heart.  ...  At each timestep, by an operator splitting technique, the space-dependent but linear diffusion part and the nonlinear but space-independent reactions part in the partial differential equations are integrated  ...  Next a locally refined fine grid is generated based on available coarse data. Then the algorithm integrates the system on the fine level grid with a small timestep.  ... 
doi:10.1155/2015/137482 pmid:26581455 pmcid:PMC4637156 fatcat:xqwzoqgw2zbu5bv5acnm6k5gym

Adaptive fuzzy segmentation of magnetic resonance images

D.L. Pham, J.L. Prince
1999 IEEE Transactions on Medical Imaging  
Because of the potential size of 3-D image data, we also describe a new faster multigrid-based algorithm for its implementation.  ...  An algorithm is presented for the fuzzy segmentation of two-dimensional (2-D) and three-dimensional (3-D) multispectral magnetic resonance (MR) images that have been corrupted by intensity inhomogeneities  ...  Priebe for their support in this work.  ... 
doi:10.1109/42.802752 pmid:10571379 fatcat:sim4gp7pazapzfw2aukyf5nnhm

Adaptive mesh refinement for simulation of thin film flows

Yibao Li, Darae Jeong, Junseok Kim
2013 Meccanica (Milano. Print)  
The resulting nonlinear discrete equation is solved using a nonlinear full approximation storage multigrid algorithm with adaptive mesh refinement techniques.  ...  We present a robust and accurate numerical method for simulating gravity-driven, thin-film flow problems.  ...  Figure 2 shows a schematic diagram of blockstructured local refinement with a four level AMR method. A pointwise Gauss-Seidel relaxation scheme is used as the smoother in the multigrid method.  ... 
doi:10.1007/s11012-013-9788-6 fatcat:duwrnjvnn5hh3edz4ujoajztde

Topology-Aware Performance Optimization and Modeling of Adaptive Mesh Refinement Codes for Exascale

Cy P Chan, John D Bachan, Joseph P Kenny, Jeremiah J Wilke, Vincent E Beckner, Ann S Almgren, John B Bell
2016 2016 First International Workshop on Communication Optimizations in HPC (COMHPC)  
Mota Mapper generates multiobjective, network topology-aware box mappings, which we apply to optimize the data layout for the example multigrid solvers.  ...  We introduce a topology-aware performance optimization and modeling workflow for AMR simulation that includes two new modeling tools, ProgrAMR and Mota Mapper, which interface with the BoxLib AMR framework  ...  The technique we employ is a mainstay for any pure-functional programmer: the monad [25] .  ... 
doi:10.1109/comhpc.2016.008 dblp:conf/sc/ChanBKWBAB16 fatcat:g3moavjnpfcmfplyazisu2etaa

Sonar image segmentation using an unsupervised hierarchical MRF model

M. Mignotte, C. Collet, P. Perez, P. Bouthemy
2000 IEEE Transactions on Image Processing  
For the estimation step, we use an iterative technique which combines a maximum likelihood approach (for noise model parameters) with a least-squares method (for MRF-based prior).  ...  In order to model more precisely the local and global characteristics of image content at different scales, we introduce a hierarchical model involving a pyramidal label field.  ...  ACKNOWLEDGMENT The authors thank Groupe d'Étude Sous Marine de l'Atlantique (GESMA), Brest, for having provided numerous real sonar pictures.  ... 
doi:10.1109/83.847834 pmid:18262959 fatcat:kz3ma6lv2rfedc25qduu2zcnpi

Nonlinear Registration and Template-Driven Segmentation [chapter]

Simon Warfield, Andre Robatino, Joachim Dengler, Ferenc Jolesz, Ron Kikinis
1999 Brain Warping  
This investigation was supported (in part) by a Postdoctoral Fellowship from the National Multiple Sclerosis Society (SW).  ...  alignment of a model of anatomy with particular data for the purpose of segmentation (segmentation by registration).  ...  Local transforms for each structure were then computed to refine the match. The final step involved manual editing of the VOI contours to maximize the match accuracy.  ... 
doi:10.1016/b978-012692535-7/50080-x fatcat:yvg63jiblzgopdogu46evqtkqy

Dense estimation and object-based segmentation of the optical flow with robust techniques

E. Memin, P. Perez
1998 IEEE Transactions on Image Processing  
As for motion estimation, we minimize an objective function involving two robust terms.  ...  We then propose an extension of the model by attaching to it a flexible object-based segmentation device based on deformable closed curves (different families of curve equipped with different kinds of  ...  Machecourt for his help in setting up the segmentation part of this work.  ... 
doi:10.1109/83.668027 pmid:18276286 fatcat:yy7anqtk5jaodlxc6ufdfbh2ie

Multiscale Segmentation Techniques for Textile Images [chapter]

Xiqun Lu
2011 Image Segmentation  
prepare training data for training-based supervised image segmentation [7, 8] .  ...  Introduction In this chapter we focus on image segmentation techniques for some very special imagestextile images.  ...  Multiscale Segmentation Techniques for Textile Images, Image Segmentation, Dr.  ... 
doi:10.5772/14508 fatcat:c4k3kug7nzeztaghaydv4mhm7i

Multilevel Spectral Partitioning for Efficient Image Segmentation and Tracking

D. Tolliver, R.T. Collins, S. Baker
2005 2005 Seventh IEEE Workshops on Applications of Computer Vision (WACV/MOTION'05) - Volume 1  
Results are presented for image segmentation and tracking problems.  ...  Within this framework, a coarse solution obtained with a standard eigensolver is propagated to increasingly fine problem instances and refined using subspace iterations.  ...  This approach was applied to image segmentation problems using the normalized cut criterion [11] . The method yields an order of magnitude speed improvement over current sampling techniques.  ... 
doi:10.1109/acvmot.2005.83 dblp:conf/wacv/TolliverCB05 fatcat:lp7l3ynkdbap7hbbkbyb34sng4

Segmentation of brain 3D MR images using level sets and dense registration

C Baillard, P Hellier, C Barillot
2001 Medical Image Analysis  
This paper presents a strategy for the segmentation of brain from volumetric MR images which integrates 3D segmentation and 3D registration processes.  ...  The registration is achieved through a robust multiresolution and multigrid minimization scheme.  ...  Acknowledgements that a variational approach mixed with region-based analysis (statistical models) is particularly robust and sensitive.  ... 
doi:10.1016/s1361-8415(01)00039-1 pmid:11524225 fatcat:yhuqdsghxjdufbayakk7t3aipq

Quadratic Markovian Probability Fields for Image Binary Segmentation

Mariano Rivera, Pedro P. Mayorga
2007 2007 IEEE 11th International Conference on Computer Vision  
In this work we present a new Markov Random Field model for image binary segmentation that computes the probability that each pixel belongs to a given class.  ...  We performed a meticulous comparison (with state of the art methods: Graph Cut, Random Walker and GMMF) for the interactive image segmentation (based on trimaps).  ...  The convergence is guaranteed to a local minima. See [21] for details.  ... 
doi:10.1109/iccv.2007.4409119 dblp:conf/iccv/RiveraM07 fatcat:rc4ixqlsyzgzdi6q7ru4go5qly

Adaptive mesh refinement for hyperbolic partial differential equations

Marsha J Berger, Joseph Oliger
1984 Journal of Computational Physics  
This is the same type of approach used by multigrid practitioners (Brandt, [1977] ), except that their data structure limits them to one refined region per row.  ...  In this dissertation we present a numerical method based on local grid refinements in both space and time for efficiently solving equations whose solutions are locally irregular.  ... 
doi:10.1016/0021-9991(84)90073-1 fatcat:d5si4bed55fifojkmx2evrwiya
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