William F. Mitchell
- computer scientist, NIST, Gaithersburg, MD, 1993-present
- senior member engineering staff, Advanced Technology Laboratory, General Electric Corporation, Moorestown, NJ, 1988-1993
- graduate assistant (teaching and research) at each university (see Education), 1977-1988
William F. Mitchell (Bill Mitchell) is a member of the Mathematical Software Group of the Applied and Computational Mathematics Division of the Information Technology Laboratory at the National Institute of Standards and Technology (NIST). He received his Ph.D. in computer science from the University of Illinois at Urbana-Champaign under the direction of Prof. Robert Skeel in 1988. He is known for his research in the numerical solution of partial differential equations, in particular adaptive mesh refinement (newest vertex bisection of triangles, hp-adaptive methods), multigrid methods (hierarchical basis multigrid, hp-multigrid for high order finite elements), parallel methods (full domain partition), and dynamic load balancing (refinement-tree based partition, a form of space filling curve), and his development of the Fortran 90 interface for the OpenGL graphics library (f90gl). He also collaborates with NIST scientists to apply these methods to simulations of physics applications such as the interaction of ultra-cold neutral atoms held in an optical trap, scanning electron microscope images, quantum dot structures, and crystal growth. He is an associate editor of the Journal of Numerical Analysis, Industrial and Applied Mathematics (2006-present) and its predecessor Applied Numerical Analysis and Computational mathematics (2001-2005), is on the scientific committee of the International Conference of Numerical Analysis and Applied Mathematics (ICNAAM, 2003-present), and organized or chaired minisymposia and technical sessions at numerous conferences. He has refereed papers for more than 30 journals and conferences, and served on review panels for the National Science Foundation (NSF) and the Department of Energy (DOE). He is a member of the Association of Computing Machinery (ACM) and the Society for Industrial and Applied Mathematics (SIAM).
- vita (pdf, 139K)
- PHAML - PHAML (Parallel Hierarchical Adaptive MultiLevel) is a Fortran 90 parallel (MPI message passing and/or OpenMP shared memeory) implementation of a finite element partial differential equation solver with adaptive mesh refinement and multigrid solver. PHAML is an active research project, but the current version of the software is available.
- Adaptive Mesh Refinement Benchmark Problems - The development of new algorithms and computer codes for the solution of partial differential equations (PDEs) usually involves the use of proof-of-concept test problems. Such test problems have a variety of uses such as demonstrating that a new algorithm is effective, verifying that a new code is correct in the sense of achieving the theoretical order of convergence, and comparing the performance of different algorithms and codes. The purpose of this web resource is to provide a standard set of problems suitable for benchmarking and testing adaptive mesh refinement algorithms and error estimators. The problems exhibit a variety of types of singularities (e.g. point and line singularities on the boundary and in the interior), near singularities (e.g. sharp peaks, boundary layers, and wave fronts), and other difficulties.
- Zoltan (in collaboration with Sandia National Laboratories) - the Zoltan Dynamic Load-Balancing Library provides critical capability to a number of parallel applications. Zoltan includes a suite of algorithms for dynamically computing partitions of problems over sets of processors; geometric, tree-based and graph-based algorithms are included. Zoltan's object-oriented interface is easy-to-use and enables Zoltan to be used by a number of different applications. Zoltan is designed to be flexible and extensible, so different algorithms can be used, compared and added easily.
- f90gl - f90gl is a fortran interface for Mesa, a freely distributable 3D graphics library with an API which is very similar to that of OpenGL, and GLUT, a window system independent API toolkit for writing OpenGL programs. It provides both fortran 77 and fortran 90 interfaces, and can also be used with native OpenGL implementations.
- StopWatch - StopWatch is a Fortran 90 module for portable, easy-to-use measurement of execution time of program segments. It supports multiple watches simultaneously, each with four clocks (total cpu, user cpu, system cpu, and wall clock). StopWatch is used by inserting subroutine calls into your source code, where the subroutine calls correspond to the buttons of a stop watch.
- MGGHAT - MGGHAT (MultiGrid Galerkin Hierarchical Adaptive Triangles) is a Fortran program for the solution of second order two dimensional elliptic partial differential equations, using adaptive refinement of second, third, or fourth order elements, and multigrid solution techniques.
- SIAM Conference on Computational Science and Engineering (SIAM CSE'17), Atlanta, GA, February 27 - March 3, 2017.
- The complete list
- U.S. Department of Commerce Bronze Medal for Superior Federal Service (1996)
- NIST Information Technology Laboratory Outstanding Authorship Award, Best Journal Paper (2007)