# Esmond G. Ng

Esmond Ng has more than 35 years of experience in research and development in high-performance numerical algorithms and scientific computing, including 30 years of working with and at Department of Energy national laboratories. He currently heads the Applied Mathematics Department in the Computational Research Division at Lawrence Berkeley National Laboratory.

His research interests are scientific computing, including sparse matrix computation, numerical linear algebra, large-scale computing, high-performance and parallel computing; mathematical software development and software engineering; and computational complexity and combinatorial scientific computing.

** Sparse Matrix Computation**Ng is one of the leading experts in sparse matrix computation and well known for his work on the theoretical aspect of sparse matrix computation and the development of efficient sparse matrix algorithms. He was a key contributor of the well-known SPARSPAK package, which was one of the first efficient and reliable software packages for solving large sparse systems of linear equations. The package was used widely in industry (such as Boeing and NASA) and universities.

His research includes combinatorial aspect of sparse matrix computation, design and implementation of reliable and efficient sparse matrix algorithms for advanced computer architectures, and complexity analysis. He is heavily involved in computational science and engineering, and has been engaging in the development and application of sparse matrix techniques for solving large-scale scientific problems, particularly.

Ng’s research has provided a theoretical understanding of structural properties and issues in sparse matrix factorizations. He was one of the first to study the effect of, and interplay between, row and column permutations in sparse orthogonal factorization and sparse Gaussian elimination with partial pivoting. His theoretical work has provided a foundation for subsequent sparse matrix research, and the algorithmic development has provided insight that influences subsequently development of sparse matrix factorization algorithms.

The sparse matrix algorithms that Ng and his collaborators have developed are well known and have been used in a large variety of scientific and engineering applications, such as structural analysis, numerical optimization, computational fluid dynamics, and finite element calculations.

** Computational Sciences and Engineering**Ng has been actively involved in the application of sparse matrix techniques to scientific and engineering applications for the last 15 years. In particular, he has been a leader in DOE’s Scientific Discovery through Advanced Computing (SciDAC) program since 2001. He has led a team of computational mathematicians that works closely with domain scientists, and develops and applies sparse matrix techniques to solve challenging, large-scale DOE scientific problems.

His efforts have accelerated scientific discoveries, which include detecting design defects in accelerator cavities through modeling and simulation for the upgrade of the DOE Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson National Accelerator Laboratory; predicting the properties of the Fluorine-14 isotope through simulation before it was detected experimentally in 2010 at the Texas A&M University’s Cyclotron Institute; and understanding the reason why the Carbon-14 isotope (which is used for carbon dating) has the long, useful lifetime. All three examples required the solution of large-scale sparse matrix problems (sparse systems of linear equations and sparse eigenvalue calculations) at the heart of the computation.

Ng is the co-author of more than 50 peer-reviewed technical papers, more than 35 conference papers and written chapters for nine books on computation. He co-authored the book “Parallel Algorithms for Matrix Computations,” which was published by the Society for Industrial and Applied Mathematics (SIAM).

Prior to joining Berkeley Lab in 1999, Ng led the Computational Methods Group at Oak Ridge National Laboratory, where he also held a joint appointment as adjunct professor at the University of Tennessee in Knoxville. Ng earned his Ph.D., master’s and bachelor’s degrees in computer science, all from the University of Waterloo in Ontario, Canada.

## Journal Articles

### Hasan Metin Aktulga, Md. Afibuzzaman, Samuel Williams, Aydın Buluc, Meiyue Shao, Chao Yang, Esmond G. Ng, Pieter Maris, James P. Vary, "A High Performance Block Eigensolver for Nuclear Configuration Interaction Calculations", IEEE Transactions on Parallel and Distributed Systems (TPDS), November 2016, doi: 10.1109/TPDS.2016.2630699

### J. Brabec, C. Yang, E. Epifanovsky, A.I. Krylov, and E. Ng, "Reduced-cost sparsity-exploiting algorithm for solving coupled-cluster equations", Journal of Computational Chemistry, January 24, 2016, 37:1059–1067, doi: 10.1002/jcc.24293

### S. L. Cornford, D. F. Martin, A. J. Payne, E. G. Ng, A. M. Le Brocq, R. M. Gladstone, T. L. Edwards, S. R. Shannon, C. Agosta, M. R. van den Broeke, H. H. Hellmer, G. Krinner, S. R. M. Ligtenberg, R. Timmermann, D. G. Vaughan, "Century-scale simulations of the response of the West Antarctic Ice Sheet to a warming climate", The Cryosphere, August 18, 2015, doi: 10.5194/tc-9-1579-2015, 2015

### H. M. Aktulga, L. Lin, C. Haine, E. G. Ng, C. Yang, "Parallel Eigenvalue Calculation based on Multiple Shift-invert Lanczos and Contour Integral based Spectral Projection Method", Parallel Computing, December 6, 2013, in press,

### H. M. Aktulga, C. Yang, E. G. Ng, P. Maris, J. P. Vary, "Improving the Scalability of a Symmetric Iterative Eigensolver for Multi-core Platforms", Concurrency and Computation: Practice & Experience, September 12, 2013, online, doi: 10.1002/cpe.3129

### S.L. Cornford, D.F. Martin, D.T. Graves, D.F. Ranken, A.M. Le Brocq, R.M. Gladstone, A.J. Payne, E.G. Ng, W.H. Lipscomb, "Adaptive mesh, finite volume modeling of marine ice sheets", Journal of Computational Physics, 232(1):529-549, 2013,

- Download File: cornfordmartinJCP2012.pdf (pdf: 1 MB)

## Conference Papers

### Ariful Azad, Mathias Jacquelin, Aydin Buluc, Esmond G. Ng, "The Reverse Cuthill-McKee Algorithm in Distributed-Memory", IEEE International Parallel & Distributed Processing Symposium (IPDPS), Orlando, FL, May 2017,

- Download File: RCM-ipdps17.pdf (pdf: 1.1 MB)

### Mathias Jacquelin, Yili Zheng, Esmond Ng, Katherine Yelick, "An Asynchronous Task-based Fan-Both Sparse Cholesky Solver", Submitted to SuperComputing'16, May 10, 2016,

### P. Maris, H. M. Aktulga, S. Binder, A. Calci, U. V. Catalyurek, J. Langhammer, E. G. Ng, E. Saule, R. Roth, J. P. Vary, C. Yang, "No Core CI calculations for light nuclei with chiral 2- and 3-body forces", J. Phys. Conf. Ser., IOP Publishing, August 1, 2013, 454:012063, doi: 10.1088/1742-6596/454/1/012063

###
P. Maris, H. M. Aktulga, M. A. Caprio, U. V. Catalyurek, E. G. Ng, D. Oryspayev, H. Potter, E.

Saule, M. Sosonkina, J. P. Vary, C. Yang, Z. Zhou,
"Large-scale Ab-initio Configuration Interaction Calculations for Light Nuclei",
J. Phys. Conf. Ser.,
IOP Publishing,
December 18, 2012,
403:012019,
doi: doi:10.1088/1742-6596/403/1/012019

### Z. Zhou, E. Saule, H. M. Aktulga, C. Yang, E. G. Ng, P. Maris, J. P. Vary, U. V. Catalyurek, "An Out-of-core Eigensolver on SSD-equipped Clusters", 2012 IEEE International Conference on Cluster Computing (CLUSTER), Beijing, China, September 26, 2012, 248 - 256, doi: 10.1109/CLUSTER.2012.76

### Z. Zhou, E. Saule, H. M. Aktulga, C. Yang, E. G. Ng, P. Maris, J. P. Vary, U. V. Catalyurek, "An Out-Of-Core Dataflow Middleware to Reduce the Cost of Large Scale Iterative Solvers", 2012 41st International Conference on Parallel Processing Workshops (ICPPW), Pittsburgh, PA, September 10, 2012, 71 - 80, doi: 10.1109/ICPPW.2012.13

### H. M. Aktulga, C. Yang, P. Maris, J. P. Vary, E. G. Ng, "Topology-Aware Mappings for Large-Scale Eigenvalue Problems", Euro-Par 2012 Parallel Processing Conference, Rhode Island, Greece, August 31, 2012, LNCS 748:830-842, doi: 10.1007/978-3-642-32820-6_82

### H. M. Aktulga, C. Yang, U. V. Catalyurek, P. Maris, J. P. Vary, E. G. Ng, "On Reducing I/O Overheads in Large-Scale Invariant Subspace Projections", Euro-Par 2011: Parallel Processing Workshops, Bordeaux, France, August 29, 2011, LNCS 715:305-314, doi: 10.1007/978-3-642-29737-3_35

### E. G. Ng, J. Sarich, S. M.Wild, T. Munson, H. M. Aktulga, C. Yang, P. Maris, J. P. Vary, N. Schunck, M. G. Bertolli, M. Kortelainen, W. Nazarewicz, T. Papenbrock, M. V. Stoitsov, "Advancing Nuclear Physics Through TOPS Solvers and Tools", SciDAC 2011 Conference, Denver, CO, July 10, 2011, arXiv:1110.1708,

### H. M. Aktulga, C. Yang, P. Maris, J. P. Vary, E. G. Ng, "Large-scale Parallel Null Space Calculation for Nuclear Configuration Interaction", 2011 International Conference on High Performance Computing and Simulation (HPCS), Istanbul, Turkey, July 8, 2011, 176 - 185, doi: 10.1109/HPCSim.2011.5999822

### Xiaoye S. Li, Meiyue Shao, Ichitaro Yamazaki, Esmond G. Ng, "Factorization-based sparse solvers and preconditioners", (SciDAC 2009) Journal of Physics: Conference Series 180(2009) 012015, 2009, doi: 10.1088/1742-6596/180/1/012015

## Book Chapters

### E. Saule, H. M. Aktulga, C. Yang, E. G. Ng, U. V. Catalyurek, "An Out-of-core Task-based Middleware for Data Intensive Scientific Computing", Handbook on Data Centers, in press, (Springer: February 1, 2014)

## Presentation/Talks

### Daniel Martin, Xylar Asay-Davis, Stephen Cornford, Stephen Price, Esmond Ng, William Collins, A Tale of Two Forcings: Present-Day Coupled Antarctic Ice-sheet/Southern Ocean dynamics using the POPSICLES model., European Geosciences Union General Assembly 2015, April 16, 2015,

- Download File: Martin-EGU-2015.pdf (pdf: 5.3 MB)

### Daniel Martin, Peter O. Schwartz, Esmond G. Ng, Improving Grounding Line Discretization using an Embedded-Boundary Approach in BISICLES, 2015 SIAM Conference on Computational Science and Engineering, March 14, 2015,

- Download File: Martin-CSE-3-15.pdf (pdf: 3.5 MB)

### Daniel Martin, Xylar Asay-Davis, Stephen Price, Stephen Cornford, Esmond Ng, William Collins, Response of the Antarctic ice sheet to ocean forcing using the POPSICLES coupled ice sheet - ocean model, Twenty-first Annual WAIS Workshop, September 25, 2014,

## Reports

### Esmond Ng, Katherine J. Evans, Peter Caldwell, Forrest M. Hoffman, Charles Jackson, Kerstin Van Dam, Ruby Leung, Daniel F. Martin, George Ostrouchov, Raymond Tuminaro, Paul Ullrich, Stefan Wild, Samuel Williams, "Advances in Cross-Cutting Ideas for Computational Climate Science (AXICCS)", January 2017, doi: 10.2172/1341564

- Download File: AXICCS-Report.pdf (pdf: 4 MB)

### Meiyue Shao, Hasan Metin Aktulga, Chao Yang, Esmond G. Ng, Pieter Maris, James P. Vary, "Accelerating nuclear configuration interaction calculations through a preconditioned block iterative eigensolver", submitted, 2016,

### W. Kramer, J. Carter, D. Skinner, L. Oliker, P. Husbands, P. Hargrove, J. Shalf, O. Marques, E. Ng, A. Drummond, K. Yelick, "Software Roadmap to Plug and Play Petaflop/s", 2006,

### Horst D. Simon, William T.C. Kramer, David H. Bailey, Michael J. Banda, E. Wes Bethel, Jonathan T. Carter, James M. Craw, William J. Fortney, John A. Hules, Nancy L. Meyer, Juan C. Meza, Esmond G. Ng, Lynn E. Rippe, William C. Saphir, Francesca Verdier, Howard A. Walter, Katherine A. Yelick, "Science-Driven Computing: NERSC's Plan for 2006-2010", 2005,

## Posters

### E.G. Ng, D.F. Martin, X. S. Asay-Davis , S.F. Price , W.D. Collins, "High-resolution coupled ice sheet-ocean modeling using the POPSICLES model", American Geophysical Union Fall Meeting, December 17, 2014,

- Download File: Ng-AGU2014.pdf (pdf: 815 KB)

### D.F. Martin, X.S.Asay-Davis, S.F. Price, S.L. Cornford, M. Maltrud, E.G. Ng, W.D. Collins, "Response of the Antarctic ice sheet to ocean forcing using the POPSICLES coupled ice sheet-ocean model", AmericanGeophysical Union Fall Meeting, December 17, 2014,

- Download File: Martin-AGU2014.pdf (pdf: 1000 KB)