NOTE: EVERYTHING BELOW THIS STATEMENT IS HOPELESSLY OUT OF DATE. A NEW WEBPAGE IS UNDER CONSTRUCTION. IN THE MEANTIME, IF YOU'RE INTERESTED IN ANY OF MY PAPERS, MY CV (LINKED ABOVE) CONTAINS LINKS TO MOST OF MY PUBLISHED AND SUBMITTED PAPERS.

Latest News

• Recent and upcoming plenary talks.
• Our group won the Teragrid Capability Computing Challenge at TeraGrid'08 for the ALPS parallel adaptive mesh framework (which was scaled up to 32K processor cores on the Ranger supercomputer)
• Openings for postdoctoral positions!
• I taught Computational Optimization of Systems Governed by PDEs in Fall 2007.
• The Quake group has won the HPC Analytics Challenge
at the IEEE/ACM SC06 conference in Tampa, FL for our entry entitled "Remote Runtime Steering of Integrated Terascale Simulation and Visualization." We demonstrated the ability to visualize and steer large-scale earthquake wave propagation simulations running at remote sites on parallel supercomputers in real time.
• I will be teaching a new class in Fall 2006 entitled Computational Methods for Geophysics.
• Brad Aagaard, Wolfgang Bangerth, and I are co-organizing the CIG Workshop on Challenges and Opportunities at the Interfaces of Scientific Computing and Computational Geodynamics . The workshop is hosted by the Institute for Computational Engineering and Sciences and the Jackson School of Geosciences, at the University of Texas at Austin, and will be held October 16-17, 2006.
• Read about our earthquake modeling work in the December 27, 2005 LinuxWorld Magazine.
• We recently held the Second Sandia Workshop on Large-scale PDE-constrained Optimization; this edition of the workshop focused on real-time and online PDE-constrained optimization.
• I'm teaching a new Biomedical Engineering course in Fall 2004 entitled Variational Image Processing (42-505/705)
• The Quake Project has been chosen one of five finalists for the Computerworld Honors 21st Century Achievement Awards, in the Science category. Our case study is now part of the Computerworld Honors permanent collection archived at over 125 museuems worldwide.
• The Quake project has won the 2003 Gordon Bell Award for Special Accomplishment, for our paper and talk at SC2003.
• The Quake project has been selected a TeraGrid Charter Application for our ITR project on multiple source earthquake inversion.
• Read about the Quake Project in this Fall 2003 Pittsburgh Supercomputing Center publication, and in the Pittsburgh Post-Gazette of Dec 15, 2003.

External Affiliations and Boards

• Editor-in-Chief, SIAM Book Series on Computational Science and Engineering
• Associate Editor, SIAM Journal on Scientific Computing
• Editorial board member, Inverse Problems
• Editorial board member, Computer Methods in Applied Mechanics and Engineering
• Editorial board member, International Journal for Multscale Computational Engineering
• Editorial board member Mathematical Modeling and Applied Computing
• Editorial board member, Advances in Computational Science and Technology
• Editorial board member, The Open Applied Mathematics Journal
• Editorial board member, Far East Journal of Mathematics
• Program Director, SIAM Activity Group on Computational Science and Engineering
• Science Steering Committee, Computational Infrastructure for Geodynamics (CIG)
• Visiting Professor, Computer Science Research Institute, Sandia National Labs
• Center for Applied Scientific Computing, Lawrence Livermore National Lab

Research Interests

• Computational Science and Engineering:
• computational biomechanics
• computational fluid dynamics
• computational geosciences
• computational solid mechanics
• Scientific Computing:
• inverse problems
• large-scale optimization
• optimal design and control
• parallel numerical algorithms
• variational image processing

Courses Recently Taught

• 12-235: Statics
• 12-331: Solid Mechanics
• 12-355: Fluid Mechanics
• 12-704: Probability and Estimation Methods for Engineering Systems
• 12-755: Finite Element Method in Mechanics I
• 12-756: Finite Element Method in Mechanics II
• 12-758: Numerical Algorithms in Computational Science and Engineering
• 12-759: Computational Optimization of Systems Governed by Partial Differential Equations
• 12-768: Computational Biofluid Dynamics
• 24-505/24-705: Variational Image Processing

Workshop & Conference Organizing Committees

• Workshop on Advances in Continuous Optimization, Reykjavik, Iceland, June 30 - July 1, 2006.
• SIAM Conference on Parallel Processing for Scientific Computing (PP06), San Francisco, CA, February 22-25, 2006.
• Sandia Workshop on Robust Large-Scale Optimization, Santa Fe, NM, August 31 - September 2, 2005.
• 3rd SIAM Conference on Computational Science and Engineering (CSE05), Orlando, FL, February 12-15, 2005.
• Second Sandia Workshop on PDE-Constrained Optimization: Towards Real-time and Online PDE Optimization, Santa Fe, New Mexico, May 19-21, 2004.
• SIAM Conference on Parallel Processing for Scientific Computing (PP04), San Francisco, CA, February 25-27, 2004.
• 2nd SIAM Conference on Computational Science and Engineering (CSE03), San Diego, CA, February 9-13, 2003.
• Optimization in Simulation-Based Models, Institute for Mathematics and its Applications Year on Optimization, Workshop 4, January 8-16, 2003, Minneapolis, MN.
• First Sandia Workshop on PDE-Constrained Optimization, Santa Fe, New Mexico, April 4-6, 2001.

• Quake Project (earthquake ground motion modeling in large basins, joint with Jacobo Bielak, Yoshi Hisada, Loukas Kallivokas, Dave O'Hallaron, Jonathan Shewchuk, and Thomas Gross; formerly NSF Grand Challenge and now NSF KDI project)
• TAOS Project (Terascale Algorithms for Optimization of Simulations, joint with Larry Biegler, Carnegie Mellon University). See George Biros' PDE-constrained optimization software library Veltisto
• Sangria Project (NSF-ITR project on simulation of flows with dynamic interfaces on multi-teraflop computers, with applications to microstructural blood flow modeling; joint with Guy Blelloch, Gary Miller, and Noel Walkington at CMU, Jim Antaki at UPMC, George Turkiyyah at U of Washington, K. Rajagopal at Texas A&M, and others.)
• Terascale simulation-constrained optimization project (Computer Science Research Institute, Sandia National Labs
• TOPS (Terascale Optimal PDE Simulations) Center a DOE SciDAC (Scientific Discovery through Advanced Computing) ISIC (Integrated Software Infrastructure Center) (with Argonne, Lawrence Livermore, Lawrence Berkeley, Old Dominion, UC Berkeley, CU-Boulder, Courant, and Tennessee
• Caliente Project Real Time Optimization for Data Assimilation and Control of Large Scale Dynamic Simulations (NSF-ITR project with Larry Biegler (CMU), George Biros (Courant), Frank Fendell (Fendell Associates), Matthias Heinkenschloss (Rice), David Keyes (Old Dominion), Bart van Bloemen Waanders (Sandia), David Young (Boeing). Press release
• ALADDIN Center (Algorithm Adaptation, Dissemination, and Integration) Carnegie Mellon University

Past Research Projects

• Streamliner Project (artificial heart optimal design, joint with Jim Antaki and Greg Burgreen, University of Pittsburgh Medical Center)
• Algor Project (computational methodologies for coupled nonlinear field problems, joint with Jacobo Bielak)
• Project Hippocrates (biomechanics-based surgical simulation, joint with Loukas Kallivokas, and Branko Jaramaz and Tony DiGioia, Shadyside Hospital; part of an NSF HPCC National Challenge project

Books

• L. Biegler, O. Ghattas, M. Heinkenschloss, and B. van Bloemen Waanders, eds., Large-Scale PDE-Constrained Optimization, Springer-Verlag, Lecture Notes in Computational Science and Engineering, Vol. 30, July 2003.

On-Line Papers

• Eric J. Schwabe, Guy E. Blelloch, Anja Feldmann, Omar Ghattas, John R. Gilbert, Gary L. Miller, David R. O'Hallaron, Jonathan R. Shewchuk, and Shang-Hua Teng, A Separator-Based Framework for Automated Partitioning and Mapping of Parallel Algorithms for Numerical Solution of PDEs, Proceedings of the 1992 DAGS/PC Symposium, Dartmouth Institute for Advanced Graduate Studies, pages 48-62, June 1992. Abstract (with BibTeX citation), PostScript (2.2Mb, 15 pages).
• Jonathan R. Shewchuk and Omar Ghattas, A Compiler for Parallel Finite Element Methods with Domain-Decomposed Unstructured Meshes, Proceedings of the Seventh International Conference on Domain Decomposition Methods in Scientific and Engineering Computing (Pennsylvania State University), Contemporary Mathematics 180 (David E. Keyes and Jinchao Xu, editors), pages 445-450, American Mathematical Society, October 1993. Abstract (with BibTeX citation), PostScript (color, 1.2Mb, 6 pages).
• S. Bollapragada, O. Ghattas and J. N. Hooker, Optimal design of truss structures by mixed logical and linear programming, 1995.
• Omar Ghattas and Xiaogang Li, "A variational finite element method for stationary nonlinear fluid-solid interaction", Journal of Computational Physics , Vol. 121, p. 347-356, 1995.
• Hesheng Bao, Jacobo Bielak, Omar Ghattas, Loukas F. Kallivokas, David R. O'Hallaron, Jonathan R. Shewchuk, and Jifeng Xu, Earthquake Ground Motion Modeling on Parallel Computers, Supercomputing '96 (Pittsburgh, Pennsylvania), November 1996. Abstract (with BibTeX citation), PostScript (color, 9.4Mb, 19 pages), Compressed PostScript (1.0Mb), and HTML.
• Omar Ghattas and Carlos Orozco, "A parallel reduced Hessian SQP method for shape optimization", Multidisciplinary Design Optimization: State of the Art , Natalia M. Alexandrov and M.Y. Hussaini, eds., SIAM, p.133-152, 1997.
• Hesheng Bao, Jacobo Bielak, Omar Ghattas, Loukas F. Kallivokas, David R. O'Hallaron, Jonathan R. Shewchuk, and Jifeng Xu, Large-scale Simulation of Elastic Wave Propagation in Heterogeneous Media on Parallel Computers, Computer Methods in Applied Mechanics and Engineering, v.152, p.85-102, 1998. Abstract(with BibTex citation), Compressed PostScript (4.3Mb) and HTML.
• Omar Ghattas and Jai-Hyeong Bark, Optimal control of two- and three-dimensional Navier-Stokes flows, Journal of Computational Physics, Vol. 136, p. 231-244, 1997. Abstract (with BibTex citation), Compressed PostScript (0.7Mb).
• Anja Feldmann, Omar Ghattas, John R. Gilbert, Gary L. Miller, David R. O'Hallaron, Eric J. Schwabe, Jonathan R. Shewchuk, and Shang-Hua Teng, Automated Parallel Solution of Unstructured PDE Problems, working paper. PostScript (b/w, 1.7Mb, 19 pages), PostScript (color, 1.8Mb, 19 pages). Because color printing is expensive, you may want to print a complete black and white copy; then use a color printer to print the following file (which contains only the five color pages) and replace the corresponding black and white pages. PostScript (color pages only, 0.8Mb, 5 pages).
• Jacobo Bielak, Jifeng Xu, and Omar Ghattas, On Earthquake Ground Motion and Structural Response in Alluvial Valleys, Technical Report CMU-CML-97-101, June 1997. Abstract(with BibTex citation), Compressed PostScript (color, 1.1Mb, 29 pages).
• Omar Ghattas and Xiaogang Li, Domain decomposition methods for sensitivity analysis of a nonlinear aeroelasticity problem, International Journal of Computational Fluid Dynamics, Vol. 11, pp 113-130, 1998. (Special issue on flow control and optimization). Abstract,PostScript (1.6Mb, 22 pages).
• Beichang He, Omar Ghattas, and James F. Antaki, Computational Strategies for Shape Optimization of Time-Dependent Navier-Stokes Flows , Technical Report CMU-CML-97-102, Computational Mechanics Lab, Department of Civil and Environmental Engineering, Carnegie Mellon University, June 1997. Abstract (with BibTex Citation), Compressed PostScript (color, 1.08 Mb, 33 pages; careful: this decompresses to 23.1Mb!),Portable Document Format (color, 0.74 Mb, 33 pages).
• George Biros and Omar Ghattas, Parallel preconditioners for KKT systems arising in optimal control of viscous incompressible flows, Proceedings of Parallel CFD '99, Williamsburg, Virginia, USA, May 23-26, 1999 (revised June 23, 1999). PostScript (360k, 8 pages), Portable Document Format (153k, 8 pages).
• George Biros and Omar Ghattas, Parallel Newton-Krylov Methods for PDE-constrained optimization, Proceedings of Supercomputing 99, Portland, Oregon, USA, November 13-19, 1999. PostScript (117k, 13 pages), Portable Document Format (96k, 13 pages).
• James F. Antaki, Guy E. Blelloch, Omar Ghattas, Ivan Malcevic, Gary L. Miller, and Noel J. Walkington, A Parallel Dynamic-Mesh Lagrangian Method for Simulation of Flows with Dynamic Interfaces, Proceedings of SC 2000, Dallas, Texas, USA, November 4-10, 2000. Portable Document Format (2.1Mb).
• George Biros and Omar Ghattas, A Lagrange-Newton-Krylov-Schur Method for PDE-Constrained Optimization, SIAG/OPT News and Views (the newsletter of the SIAM Activity Group on Optimization), Vol. 11, No. 2, August 2000. This is a short (6 pages), high-level introduction to the LNKS method for PDE-constrained optimization. Portable Document Format (62Kb).
• V. Akcelik, B. Jaramaz, and O, Ghattas, Nearly Orthogonal Two-Dimensional Grid Generation with Aspect Ratio Control, Journal of Computational Physics, 171(2):805-821, 2001. Portable Document Format (0.6 Mb).
• Jifeng Xu, Jacobo Bielak, Omar Ghattas, and Jianlin Wang, Three-dimensional nonlinear seismic ground motion modeling in inelastic basins, Physics of the Earth and Planetary Interiors, 137(1-4):81-95, 2003. Portable Document Format (3.0 Mb).
• Volkan Akcelik, George Biros, and Omar Ghattas, Parallel Multiscale Gauss-Newton-Krylov Methods for Inverse Wave Propagation, Proceedings of the IEEE/ACM SC2002 Conference, Baltimore, November 2002. Received Best Technical Paper Award. Portable Document Format (0.6 Mb).
• George Biros and Omar Ghattas, Inexactness Issues in Lagrange-Newton-Krylov-Schur Methods for PDE-Constrained Optimization, Technical Report, Mechanics, Algorithms, and Computing Lab, Carnegie Mellon University, 2002. Portable Document Format (0.5Mb).
• Volkan Akcelik, George Biros, Omar Ghattas, Kevin R. Long, and Bart van Bloemen Waanders, A Variational Finite Element Method for Source Inversion for Convective-Diffusive Transport, Finite Elements in Analysis and Design, 39:683-705, 2003. Portable Document Format (3.5 Mb).
• Volkan Akcelik, Jacobo Bielak, George Biros, Ioannis Epanomeritakis, Antonio Fernandez, Omar Ghattas, Eui Joong Kim, Julio Lopez, David O'Hallaron, Tiankai Tu, John Urbanic, High-resolution forward and inverse earthquake modeling on terascale computers, Proceedings of ACM/IEEE SC2003, Phoenix, AZ, 2003. This paper won the 2003 Gordon Bell Award for Special Accomplishment. Portable Document Format (11.7Mb)
• Kwan-Liu Ma, Aleksander Stompel, Jacobo Bielak, Omar Ghattas, and Eui Joong Kim, Visualizing Large-Scale Earthquake Simulations,, Proceedings of ACM/IEEE SC 2003, Phoneix, AZ, 2003. PDF
• E. Kim, J. Bielak, and O. Ghattas, Large-scale Northridge Earthquake simulation using octree-based multiresolution mesh method, Proceedings of 16th ASCE Engineering Mechanics Conference, Seattle, Washington, July 2003. Portable Document Format (2.4Mb).
• Volkan Akcelik, Jacobo Bielak, George Biros, Ioannis Epanomeritakis, Omar Ghattas, Loukas F. Kallivokas, Eui Joong Kim, A framework for online inversion-based 3D site characterization, Proceedings of the International Conference on Computational Science, Krakow, Poland, June 2004. Portable Document Format (0.9Mb).
• Judith Hill, Noel Walkington, and Omar Ghattas, A parallel Eulerian method for flows with elastic membranes, technical report, Ultrascale Simulation Laboratory, 2004. Portable Document Format (0.9Mb).
• LF Kallivokas, SW Na, O Ghattas, B Jaramaz, Assessment of a fictitious domain method for patient-specific modeling of press-fit orthopaedic implantation , submitted Portable Document Format (1.9Mb).
• V Akcelik, G Biros, A Draganescu, O Ghattas, J Hill, and B van Bloeman Waanders, Dynamic data-driven inversion for terascale simulations: Real-time identification of airborne contaminants, Proceedings of SC2005, Seattle, WA, November 2005. Portable Document Format (0.4Mb).
• V Akcelik, G Biros, O Ghattas, D Keyes, K Ko, LQ Lee, and E Ng, Adjoint methods for electromagnetic shape optimization of the low-loss cavity for the International Linear Collider, Journal of Physics Conference Series. Portable Document Format (0.2Mb).
• T. Tu, D. O'Hallaron, and O. Ghattas, Scalable parallel octree meshing for terascale applications, Proceedings of SC2005, Seattle, WA, November 2005. Portable Document Format (0.2Mb).
• K. Willcox, O. Ghattas, B. van Bloemen Waanders, and B. Bader, An optimization framework for goal-oriented model-based reduction of large-scale systems, Proceedings of IEEE Conferene on Decision and Control, Seville, Spain, December 12-15, 2005. Portable Document Format (0.5Mb).
• George Biros and Omar Ghattas, Parallel Lagrange-Newton-Krylov-Schur Methods for PDE-Constrained Optimization. Part I: The Krylov-Schur Solver, SIAM Journal on Scientific Computing, 27(2):687-713, 2005. Portable Document Format (0.7Mb).
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• George Biros and Omar Ghattas, Parallel Lagrange-Newton-Krylov-Schur Methods for PDE-Constrained Optimization. Part II: The Lagrange-Newton Solver, and its Application to Optimal Control of Steady Viscous Flows. SIAM Journal on Scientific Computing, 27(2):714-739, 2005. Portable Document Format (2.0Mb).
• Jacobo Bielak, Omar Ghattas, and Eui Joong Kim, Parallel octree-based finite element method for large-scale earthquake ground motion simulation, Computer Modeling in Engineering and Sciences, 10(2):99-112, 2005. Portable Document Format (3.7Mb).
• V. Akcelik, G. Biros, O. Ghattas, J. Hill, D. Keyes, and B. van Bloemen Waanders, Parallel algorithms for PDE-constrained optimization, in Frontiers of Parallel Computing, M. Heroux, P. Raghaven, and H. Simon, eds, SIAM, 2006. Portable Document Format (0.3 Mb) .
• Tiankai Tu, Hongfeng Yu, Leonardo Ramirez-Guzman, Jacobo Bielak, Omar Ghattas, Kwan-Liu Ma, David R. O'Hallaron, From Mesh Generation to Scientific Visualization: An End-to-End Approach to Parallel Supercomputing, Proceedings of SC'06, Tampa, FL, Nov 2006.
• Hongfeng Yu, Tiankai Tu, Jacobo Bielak, Omar Ghattas, Julio Lopez, Kwan-Liu Ma, David R. O’Hallaron, Leonardo Ramirez-Guzman, Nathan Stone, Ricardo Taborda-Rios, and John Urbanic, Scalable End-to-End Parallel Supercomputing and Application to Real-time Earthquake Modeling, Analytics Challenge Award, SC06, Tampa, FL, Nov. 2006.
• T. Bui-Thanh, K. Willcox, O. Ghattas, and B. van Bloemen Waanders Goal-oriented, model-constrained optimization for reduction of large-scale systems, Journal of Computational Physics, in press.
• O. Bashir, K. Willcox, O. Ghattas, B. van Bloemen Waanders, and J. Hill, Hessian-based model reduction for large-scale systems with initial condition inputs, International Journal for Numerical Methods in Engineering, in press.

PhD Students (former and current)

• Carlos Orozco, "Large-Scale Shape Optimization: Numerical Methods, Parallel Algorithms, and Applications to Aerodynamic Design," May 1993. Currently Assistant Professor, Department of Civil Engineering and Applied Mechanics, University of Virginia.
• Xiaogang Li, "A Variational Finite Element Method for Fully-coupled Nonlinear Fluid-Solid Interaction," December 1995. Currently at Algor, Inc., Pittsburgh, PA.
• Jaihyeong Bark, "Optimal Velocity Control of Navier-Stokes Flows, with Applications to Viscous Drag Reduction," December 1995. Currently Assistant Professor, Department of Architectural Engineering, Mok-Won University, Korea.
• Beichang He, "Shape Optimization of Navier-Stokes Flows, with Application to Design of Artificial Heart Devices," May 1996. Currently at General Electric Corporate Research and Development, Schenectady, NY.
• Jifeng Xu, Three-dimensional Simulations of Wave Propagation in Inelastic Media on Parallel Computers with Application to Seismic Response, January 1998 (co-advised with J. Bielak). Currently Mathematics and Computing Specialist, Mathematics & Engineering Analysis, Boeing Phantom Works, Bellevue, WA.
• Hesheng Bao, "Finite Element Simulation of Earthquake Ground Motion in Realistic Basins," February 1998 (co-advised with J. Bielak). Currently at Algor, Inc., Pittsburgh, PA.
• George Biros, "Parallel Algorithms for PDE-Constrained Optimization, with Applications to Optimal Flow Control," September 2000. Currently assistant professor, Mechanical Engineering & Applied Mechanics and Computer Science, University of Pennsylvania.
• Ivan Malcevic, "A Parallel Dynamic Mesh Lagrangian Method for Navier Stokes Flows with Deformable Boundaries," May 2001. Currently member of the technical staff, Engineering Mechanics Laboratory, General Electric Company, Niskayuna, NY.
• Volkan Akcelik, "Multiscale Newton-Krylov methods for inverse acoustic wave propagation," February 2002 (co-advised with Branko Jaramaz). Currently research scientist, Stanford Linear Accelerator Center.
• Eui Joong Kim, Parallel octree-based multi-resolution mesh method for large-scale earthquake ground motion simulation, May 2003. (co-advised with Jacobo Bielak). Currently postdoc, Duke University.
• Larisa Goldmints , Patient-Specific Biomechanical Modeling in Pre-operative Surgical Planning, May 2003 (co-advised with Branko Jaramaz). Currently postdoc, RPI.
• Judy Hill, Eulerian phase field methods for flows with elastic membranes, May 2004 (co-advised with Noel Walkington). Currently member of technical staff, Sandia National Labs.
• Clemens Kadow, Parallel Delaunay refinement mesh generation, May 2004 (co-advised with Noel Walkington, Guy Blelloch, and Gary Miller). Currently with McKinsey & Company
• Alexandre Cunha, A Fully Eulerian Method for Shape Optimization with Application to Navier Stokes Flows, September 2004. Currently postdoc, UCLA.
• Ioannis Epanomeritakis, Identification of Elastic Basin Properties by Large-scale Inverse Earthquake Wave Propagation, September 2004 (co-advised with Jacobo Bielak). Currently consultant, Greece.
• Ioanna Pagani, Mechanics of red blood cell membranes, January 2006 (co-advised with Phil LeDuc). Currently, postdoc, UC Berkeley.
• Aysegul Askan, Inverse viscoelastic wave propagation (co-advised with Jacobo Bielak)
• Pearl Flath
• Shan Yang
• Jennifer Deiringer
• James Martin (co-advised with Tom Hughes)
• Scott Lipton (co-advised with Tom Hughes)