# Presentation: 209202

##                                  U.S. Department of Energy’s                                Office of Science

- Advanced Scientific Computing Research
- Strategic Planning workshop

**Dan Hitchcock**
*22 July 2003*

**A Science-based Case for Large-Scale Simulation (SCaLeS)**

## Original Charge(April 2003, Polansky)

- “Identify rich and fruitful directions for the computational sciences from the perspective of scientific and engineering applications”
- Build a “strong science case for an ultra-scale computing capability for the Office of Science”
- “Address major opportunities and challenges facing computational sciences in areas of strategic importance to the Office of Science”
-  “Report by July 30, 2003”
- “Foster additional workshops, meetings and discussions on specific topics that can be identified and analyzed over the course of the next year”
- Though our formal charge is Office of Science-centric, the report may ultimately be combined with others in a multiagency thrust, and should be prepared with a broader science case and need not be confined scientifically to Office of Science interests alone

## Envisioning the report

- Dozens of authors from labs and universities
- Editorial oversight by small board, including expertise from each Office
- Written hierarchically, with easy-to-read summaries for Congressional staffers and in-depth sections to impress non-computational experts from scientific community
- Broad and as comprehensive as possible, as to areas touched
- Deep in a number of illustrative places, through case studies
- Written with strong awareness of antecedents and distinct mission
- Laden with good charts and good (but not gimmicky) scientific eye-candy

## Workshop planning

- Selected plenaries on context and structure
- Selected plenaries on scientific content and scaling analyses
- Parallel sessions of breakout groups organized by:
- Disciplinary areas (one session, w/approx. 10 breakouts)
- Cross-cutting discussions (two sessions)
- Parallel sessions scribed by invited and prepared graduate students; overall meeting and written products professionally scribed with DOE HQ support
- Web supported (with *a priori* and *a posteriori* postings of position papers and presentations)

## Antecedent reports

- 1982: “Large Scale Computing in Science and Engineering” (convened by NSB)
- 1992: “Grand Challenges: High Performance Computing and Communications” (OSTP)
- 1993: “From Desktop to Teraflop: Exploiting the U.S. Lead in High Performance Computing” (NSF)
- 1995: “Report of the Task Force on the Future of the NSF Supercomputer Centers Program” (NSF)
- 1999: “Information Technology Research: Investing in Our Future” (PITAC)
- 2000: “Scientific Discovery through Advanced Computing” (DOE SC)
- 2003: “Revolutionizing Science and Engineering through Cyberinfrastructure” (NSF)

## SCaLeS Workshop

- Held on 24—25 June, to provide input for a report required by 30 July(!)
- Approximately 325 participants from 11 applications areas, 8 applied mathematics areas and 8 computer science areas
- Patterned on the SciDAC approach (interdisciplinary, balance among hardware resources, applications and “enabling technologies”)
- Three main chapters for the report:  *Applications*, *Mathematics*, *Computer Science*
- Chapter editors are (resp.) Thom Dunning, Phil Colella and Bill Gropp, with David Keyes the report editor
- Two reports envisioned:  Short digestible overview report (30 July), and a longer detailed report, to be published by SIAM

## Chapter Authors / Workshop Leaders

- Applications
- Accelerator Modeling – Kwok Ko, Rob Ryne
- Astrophysics – Tony Mezzacappa, Bob Rosner
- Biology – Mike Colvin, George Michaels
- Chemistry – Robert Harrison, Theresa Windus
- Climate – John Drake, Bob Malone, Phil Jones*
- Combustion – John Bell, Larry Rahn
- Environmental – Mary Wheeler, Steve Yabusaki
- Materials – Francois Gygi, Malcolm Stocks
- Nanoscience – Peter Cummings, Lin-Wang Wang
- Plasma Science – Steve Jardin, Bill Nevins
- QCD – Bob Sugar

*** Offsite**

## Chapter Authors / Workshop Leaders

- Mathematics
- CFD/MHD – Phil Colella, Paul Fischer
- Discrete Math – Bruce Hendrickson, Alex Pothen
- Solvers and “Fast” Algorithms – Van Henson, Juan Meza
- Meshing Methods – Lori Freitag, David Serafini, David L. Brown
- Multiphysics – Dana Knoll, John Shadid
- Multiscale – Tom Hughes, Mark Shephard
- Radiation Transport / Kinetic Methods – Frank Graziani, Jim Morel
- Uncertainty – Jim Glimm, Sallie Keller-McNulty

## Chapter Authors / Workshop Leaders

- Computer Science
- Architecture – Bill Gropp, Jim Tomkins
- Access / Resource Sharing – Ian Foster*
- Data – Arie Shoshani, Dorom Rotem
- Frameworks / Environments – Rob Armstrong, Kathy Yelick
- Performance Tools / Evaluation – David Bailey
- Software Management – Steve Hammond, Rusty Lusk
- System Software – Al Geist
- Visualization – Wes Bethel, Chuck Hansen

*** Offsite**

## Table of Contents for Report Volume I

***A Science-based Case for Large-scale Simulation***
***Summary Report (Volume I)***
***Table of Contents***
**Executive summary****	****	****	****i**
**Table of Contents****	****	****	****iii**
**Attributions  ****	****	****	****	****v**
**1. Introduction****	****	****	****	****1**
**2.** **The Scientific Discovery through Advanced Computing (SciDAC) initiative****	****8**

## Table of Contents for Report (cont’d)

**3. Anatomy of a large-scale simulation****	****	****12**
**4. Opportunities at the scientific horizon****	****16**
**5. Enabling mathematics and computer science research****	****	****	****	****	****	****20**
**6. Recommendations and discussion****	****	****24**
**Postscript and Acknowledgements****	****	****33**
**Appendix I: A Brief Chronology of “A Science-based Case for Large-scale Simulation”****	****	****35**
**Appendix II: Charge for “A Science-based Case for Large-scale Simulation”****	****	****	****	****37**