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HPGMG: Benchmarking Computers Using Multigrid
04 Feb 2016 | Online Presentations | Contributor(s): Jed Brown
HPGMG (https://hpgmg.org) is a geometric multigrid benchmark designed to measure the performance and versatility of computers. For a benchmark to be representative of applications, good...
Hub Snub: Removing Vertices with High Degree from Coarse-grid Correction
04 Feb 2016 | Online Presentations | Contributor(s): Geoffry Sanders
Network scientists often employ numerical solutions to linear systems as subroutines of data mining algorithms. Due to the ill-conditioned nature of the systems, obtaining solutions with standard...
Is the Ideal Approximation Operator Always "Ideal" for a Particular C/F Splitting?
04 Feb 2016 | Online Presentations | Contributor(s): Erin Molloy
Given a coarse grid, the ideal prolongation operator is defined by , where the weight matrix, , interpolates a set of fine grid variable (-points) from a set of coarse grid...
Least-Squares Finite Element Method and Nested Iteration for Electromagnetic Two-Fluid Plasma Models
04 Feb 2016 | Online Presentations | Contributor(s): Christopher Leibs
Efforts are currently being directed towards a fully implicit, electromagnetic, JFNK-based solver, motivating the necessity of developing a fluid-based, electromagnetic, preconditioning strategy...
Monolithic Multigrid Methods for Coupled Multi-Physics Problems
04 Feb 2016 | Online Presentations | Contributor(s): Scott Maclachlan
While block-diagonal and approximate block-factorization preconditioners are often considered for coupled problems, monolithic approaches can offer improved performance, particularly when the...
Multilevel Markov Chain Monte Carlo for Uncertainty Quantification in Subsurface Flow
04 Feb 2016 | Online Presentations | Contributor(s): Christian Ketelsen
The multilevel Monte Carlo method has been shown to be an effective variance reduction technique for quantifying uncertainty in subsurface flow simulations when the random conductivity field can...
On the Design of a Finite Element Multigrid Solver for Mimetic Finite Difference Schemes
04 Feb 2016 | Online Presentations | Contributor(s): Carmen Rodrigo
The focus of this work is to study the relation between mimetic finite difference schemes on triangular grids and some finite element methods for two model problems based on curl-rot and grad-div...
On the Preconditioning of a High-Order RDG-based All-Speed Navier-Stokes Solver
04 Feb 2016 | Online Presentations | 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...
Parallel Multigrid Preconditioner Based on Automatic 3D Tetradedric Meshes
04 Feb 2016 | Online Presentations | 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...
Reducing Communication Costs for Sparse Matrix Multiplication within Algebraic Multigrid
04 Feb 2016 | Online Presentations | 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...
Seventeenth Copper Mountain Conference on Multigrid Methods
04 Feb 2016 | Workshops
Optimization and Inverse Problems
Data Mining, Large Graphs, and Markov Chains
Nonsymmetric and Indefinite Problems
Space-time constrained FOSLS with AMGe upscaling
04 Feb 2016 | Online Presentations | 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...
Stable Discretizations and Robust Block Preconditioners for Fluid-Structure Interaction Systems
04 Feb 2016 | Online Presentations | 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...
Support Graph Smoothing Techniques
04 Feb 2016 | Online Presentations | 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...
Task-Graph and Functional Programming Models: The New Paradigm
04 Feb 2016 | Online Presentations | 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...
Understanding the Propagation of Silent Data Corruption in Algebraic Multigrid
04 Feb 2016 | Online Presentations | 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...
[Illinois] CNST Nanotechnology Workshop 2015
04 Feb 2016 | Workshops | Contributor(s): Mustafa El-sayed, Mehmet Toner
The CNST Nanotechnology Workshop highlights University of Illinois research in bionanotechnology and nanomedicine, nanoelectronics and nanophotonics, and nanomaterials and nanomanufacturing,...
[Illinois] Nanotechnology meets Biology in the Cancer Cell: Applications in Medicine, Drug Delivery, and Determining Drug Efficacy
04 Feb 2016 | Online Presentations | Contributor(s): Mostafa El-Sayed
Dr. Mostafa El-Sayed received his B.Sc. from Ain Shams University in Cairo; and Ph.D. from Florida State University. He was Postdoctoral Fellow at Yale University, Harvard University and the...
[Illinois] Rare Events with Large-Impact: Bioengineering & Clinical Applications of Circulating Tumor Cells
04 Feb 2016 | Online Presentations | Contributor(s): Mehmet Toner
Dr. Mehmet Toner is the Helen Andrus Benedict Professor of Biomedical Engineering at the Massachusetts General Hospital (MGH), Harvard Medical School (HMS), and is the co-founding director of the...
[Illinois] Signal Processing at Light Speed: Ultrashort Optical Pulse Generation with Arbitrary Waveforms
29 Jan 2016 | Online Presentations | Contributor(s): Claire Mcghee
We aim to further improve early detection of cancer biomarkers, including metal ion and small molecules, using functional DNA as the selective component for photonic crystal surface enhanced Raman...