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On the Preconditioning of a High-Order RDG-based All-Speed Navier-Stokes Solver
04 Feb 2016 | | Contributor(s):: Brian Weston
We investigate the preconditioning of an all-speed Navier-Stokes solver, based on the orthogonal-basis Reconstructed Discontinuous Galerkin (RDG) space discretization, and integrated using a high-order fully-implicit time discretization method. The work is motivated by applications in Additive...
Parallel Multigrid Preconditioner Based on Automatic 3D Tetradedric Meshes
04 Feb 2016 | | Contributor(s):: Frederic Vi
Multigrid methods are efficient for solving large sparse linear systems. Geometric (GMG) and Algebraic Multigrid (AMG) have both their own benefits and limitations. Combining the simplicity of AMG with the efficiency of GMG lead us to the development of an Hybrid Multigrid preconditionner. From...
Peter Wang - Introduction of Biotechnology and Cellular Engineering
15 May 2013 | | Contributor(s):: Mohamud Yusuf Mohamed
Peter Wang, UIUC
Preconditioning for Divergence-Conforming Discretizations of the Stokes Equations
07 Feb 2016 | | Contributor(s):: Thomas Benson
Recent years have seen renewed interest in the numerical solution of the Stokes Equations. Of particular interest is the use of inf-sup stable pairs of finite elements for which weak enforcement of the incompressibility condition implies strong enforcement as well, such as with BDMelements....
Properties of Nanosilicon as a Platform for Functional Devices
21 May 2012 | | Contributor(s):: Mohamud Yusuf Mohamed
Range Decomposition: A Low Communication Algorithm for Solving PDEs on Massively Parallel Machines
07 Feb 2016 | | Contributor(s):: Tom Manteuffel
The Range Decomposition (RD) algorithm uses nested iteration and adaptive mesh refinement locally before performing a global communication step. Only several such steps are observed to be necessary before reaching a solution within a small multiple of discretization error. The target application...
Reducing Communication Costs for Sparse Matrix Multiplication within Algebraic Multigrid
04 Feb 2016 | | Contributor(s):: Grey Ballard
We consider the sequence of sparse matrix-matrix multiplications performed during the setup phase of algebraic multigrid. In particular, we show that the most commonly used parallel algorithm is often not the most communication-efficient one for all of the matrix multiplications involved. By...
Seventeenth Copper Mountain Conference on Multigrid Methods
04 Feb 2016 |
HIGHLIGHTED TOPICSUncertainty QuantificationOptimization and Inverse ProblemsData Mining, Large Graphs, and Markov ChainsNonsymmetric and Indefinite ProblemsKrylov AcceleratorsHybrid Direct-Iterative Linear SolversParallel Multigrid on Multicore Systems and Heterogeneous ArchitecturesTime...
Space-time constrained FOSLS with AMGe upscaling
04 Feb 2016 | | Contributor(s):: Panayot Vassilevski
We consider time-dependent PDEs discretized in combined space-time domains. We first reduce the PDE to a first order system. Very often in practice, one of the equations of the reduced system involves the divergence operator (in space-time). The popular FOSLS (first order system least-squares)...
Stable Discretizations and Robust Block Preconditioners for Fluid-Structure Interaction Systems
04 Feb 2016 | | Contributor(s):: Kai Yang
In our work we develop a family of preconditioners for the linear algebraic systems arising from the arbitrary Lagrangian-Eulerian discretization of some fluid-structure interaction models. After the time discretization, we formulate the fluid-structure interaction equations as saddle point...
Support Graph Smoothing Techniques
04 Feb 2016 | | Contributor(s):: Alyson Fox
Many tasks in large-scale network analysis and simulation require efficient approximation of the solution to the linear system $ Lx=b$, where $ L$ is a graph Laplacian. However, due to the large size and complexity of scale-free graphs, standard iterative methods do not perform optimally. The...
Task-Graph and Functional Programming Models: The New Paradigm
04 Feb 2016 | | Contributor(s):: Ben Bergen
The Message Passing Interface (MPI) is an example of a distributed-memory communication model that has served us well through the CISC processor era. However, because of MPI's low-level interface, which requires the user to manage raw memory buffers, and its bulk-synchronous communication...
Understanding the Propagation of Silent Data Corruption in Algebraic Multigrid
04 Feb 2016 | | Contributor(s):: Jon Calhoun
Sparse linear solvers from a fundamental kernel in high performance computing (HPC). Exascale systems are expected to be more complex than systems of today being composed of thousands of heterogeneous processing elements that operate at near-threshold-voltage to meet power constraints. The...
[Illinois] 2010 Nano-Biophotonics Summer School: Intro to Nanophotonics
14 Jun 2013 | | Contributor(s):: Kent D Choquette
Biophotonics Summer School 2010May 21st - June 1st 2010 Urbana-Champaign, IllinoisThe Biophotonics Summer School brings together from a wide variety of disciplines to teach students about the biophotonics field. In 2010, some of the topics covered included principles of biophotonics, technology...
[Illinois] Advances in Nanoindentation Techniques for Wood Cell Walls
18 Sep 2015 | | Contributor(s):: Joseph Jakes
[Illinois] AFM indentation tests reveal the poroelastic nature of the cytoplasm
19 Nov 2015 | | Contributor(s):: Emad Moeendarbary
[Illinois] B3SI 2012: Closing Session
17 Dec 2013 | | Contributor(s):: Rashid Bashir, Lizzanne DeStefano, Hsiang-Yu Angie Wang, Hao-Ming Hsiao, Jimmy K. Hsia, Laura Arriola Miller
Deeper understandings of biological systems and advances in nanotechnology have provided new opportunities to make significant progress in mechanobiology, biosensing and dynamic control of engineered systems, with wide range of applications such as cancer research. In order to take advantage of...
[Illinois] B3SI 2012: International Collaboration Panel
17 May 2013 | | Contributor(s):: Hao-Ming Hsiao, Irfan S. Ahmad, Nai-Jen Harry Chang, Taher A. Saif, Xin Tang, Hsiang-Yu Angie Wang
[Illinois] Beckman Director's Seminar - Quantitative Phase Imaging
26 Nov 2012 | | Contributor(s):: Gabriel Popescu
"Ever since the invention of the microscope in the 17th century, it has been observed that live cells are transparent under visible illumination, i.e. they do not absorb (or scatter) light significantly. Thus, a magnified image of cells will generally exhibit low contrast. In order to overcome...
[Illinois] Beckman Graduate Seminar: Dispersion-relation Spectroscopy of Intracellular Transport
18 Dec 2012 | | Contributor(s):: Ru Wang
The interior of a living cell is a busy place. Molecular motors move materials along prescribed biopolymer tracks. This sort of active transport is required to rapidly move products over large distances within the cell, where passive diffusion is too slow. Just as understanding the flow of...