
Title
Computational Mathematician 
Email
petra1@llnl.gov 
Phone
(925) 4246261 
Organization
Not Available
Cosmin G. Petra is a computational mathematician in the Center for Applied Scientific Computing at Lawrence Livermore National Laboratory. Cosmin's work focuses on highperformance computing algorithms and C/C++ solvers for mathematical optimization with emphasis on applications in complex energy systems.
Prior to joining the Center for Applied Scientific Computing, Cosmin was with Argonne National Laboratory as a computational mathematician and, prior to that, hold software engineer/numerical analyst positions in IT industry. Cosmin obtained an M.S. and a Ph.D. in Applied Mathematics from the University of Maryland, Baltimore County, in 2006 and 2009, respectively.
Research appointments
 2016present  Computer Scientist/Computational Mathematician, Center for Applied Scientific Computing, Lawrence Livermore National Laboratory.
 20152020  Adjunct Asst. Professor, School of Natural Sciences, University of California, Merced.
 20122016  Asst. Computational Mathematician, MCS Division, Argonne National Laboratory.
 20092012  Postdoctoral Appointee, MCS Division, Argonne National Laboratory.
Research interests
 Scalable algorithms for optimization, control, and design under uncertainty
 Highperformance computing algorithms for mathematical optimization at extreme scale
 Scientific computing and extremescale computing
 Power grid optimization of realworld largescale power systems
Recent and ongoing projects
 Scalable algorithms for optimization, optimal control, and optimal design
 HPC optimization solver for continuous optimization  HiOp
 Optimization of power grid systems, mainly, solving realworld AC optimal power flows with contingency analysis
20062009 Ph.D. in Applied Mathematics  University of Maryland, Baltimore County, Baltimore, Maryland
20052006 M.S. in Applied Mathematics  University of Maryland, Baltimore County, Baltimore, Maryland
19982002 B.S. in Mathematics and Computer Science  Universitatea BabesBolyai, ClujNapoca, Romania
 I. Aravena, D. K. Molzahn, S. Zhang, C. G. Petra, F. E. Curtis, S. Tu, A. Wachter, E. Wei, E. Wong, A. Gholami, K. Sun, X. Sun, S. T. Elbert, J. T. Holzer, A. Veeramany, Recent developments in securityconstrained AC optimal power flow, submitted, 2022.
 J. Wang, C. G. Petra, A nonsmooth nonconvex optimization algorithm for problems with upperC2 objective, submitted, 2022. arXiv
 J. J. Brust, R. F. Marcia, C. G. Petra, M. Saunders, RCR: Reduced Compact Representation for Largescale Optimization with Linear Equality Constraints, SIAM Journal on Scientific Computing, Volume 44, Issue 1, 2022. DOI
 C. G. Petra, M. Salazar De Troya, N. Petra, Y. Choi, G. M. Oxberry, D. Tortorelli, On the implementation of a quasiNewton interiorpoint method for PDEconstrained optimization using finite element discretizations, accepted to Optimization Methods and Software, 2022.
 C. G. Petra, I. A. Solis, Solving realistic securityconstrained optimal power flow problems, submitted, 2021. arXiv
 S. Regev, N. Chiang, E. Darve, C. G. Petra, M. A. Saunders, K. Swirydowicz, S. Peles, A Hybrid DirectIterative Method for Solving KKT Linear Systems, in review, 2021.
 J. Wang, N, Chiang, C. G. Petra, An asynchronous distributedmemory optimization solver for twostage stochastic programming problems, 20th International Symposium on Parallel and Distributed Computing (ISPDC), 2021. DOI
 J. J. Brust, S. Leyffer, C. G. Petra, Compact Representations of Structured BFGS Matrices, Computational Optimization and Applications, Volume 80, 2021. DOI
 R. Vuchkov, C. G. Petra, N. Petra, On the derivation of quasiNewton formulas for optimization in function spaces, Journal of Numerical Functional Analysis and Optimization, Volume 41, Issue 13, 2020. DOI
 J. J. Brust, R. F. Marcia, C. G. Petra, Computationally Efficient Decompositions of Oblique Projection Matrices, SIAM Journal on Matrix Analysis and Applications, Volume 41, Issue 2, 2020. DOI
 E. M. Constantinescu, N. Petra, J. Bessac, C. G. Petra, Statistical Treatment of Inverse Problems Constrained by Differential EquationsBased Models with Stochastic Terms, SIAM Journal on Uncertainty Quantification, Volume 8, Issue 1, 2020. DOI
 C. G. Petra, N. Chiang, M. Anitescu, A structured quasiNewton algorithm for optimizing with incomplete Hessian information, SIAM Journal on Optimization, Volume 29, Issue 2, 2019. DOI
 J. J. Brust, R. F. Marcia, C. G. Petra, Largescale quasiNewton trustregion methods with low dimensional linear equality constraints, Journal of Computational Optimization and Applications, Volume 74, Issue 3, 2019. DOI
 K. Kim, C. G. Petra, V. M. Zavala, An asynchronous bundletrustregion method for dual decomposition of stochastic mixedinteger programming, SIAM Journal on Optimization, Volume 29, Issue 1, 2019. DOI
 C. G. Petra, F. Potra, A Homogeneous Model for Monotone Mixed Horizontal Linear Complementarity Problems, Journal of Computational Optimization and Applications, Volume 72, Issue 1, pages 241267, 2019. DOI
 V. Rao, K. Kim, M. Schanen, D. A. Maldonado, C. G. Petra, and M. Anitescu, A Multiperiod OptimizationBased Metric of Grid Resilience, Proceedings of the 2019 IEEE PES General Meeting, 2019.
 C. G. Petra, A memorydistributed quasiNewton solver for nonlinear programming problems with a small number of general constraints, Journal of Parallel and Distributed Computing, Volume 133, pages 337348, 2019. DOI
 M. Schanen, F. Gilbert, C. G. Petra, M. Anitescu, Towards multiperiod ACbased contingency constrained optimal power flow at large scale, “Proceedings to the 20th Power Systems Computation Conference”, 2018. DOI
 C. G. Petra, F. Qiang, M. Lubin, J. Huchette, On efficient Hessian computation using the edge pushing algorithm in Julia, Optimization Methods and Software, Volume 33(46), pages 10101029, 2018. DOI
 N. Petra, C. G. Petra, Z. Zhang, E. M. Constantinescu, and M. Anitescu, A Bayesian Approach for Parameter Estimation with Uncertainty for Dynamic Power Systems, IEEE Transactions on Power Systems, Volume 32(4), pages 2735  2743, 2017. DOI.
 C. G. Petra, V. M. Zavala, E. N. Ruiz, M. Anitescu, A highperformance computing framework for analyzing the economic impacts of wind correlation, Electric Power Systems Research, Volume 141, pages 372380, 2016. DOI.
 J. Huchette, M. Lubin, C. G. Petra, Parallel algebraic modeling for stochastic optimization. The First Workshop for High Performance Technical Computing in Dynamic Languages (HPTCDL), Supercomputing 2014. DOI.
 C. G. Petra, O. Schenk, M. Anitescu. Realtime Stochastic Optimization of Complex Energy Systems on High Performance Computers. Computing in Science & Engineering (CiSE) 16(5), pages 3242. DOI.
 N. Chiang, C. G. Petra, V. M. Zavala, Structured Nonconvex Optimization of LargeScale Energy Systems Using PIPSNLP. 18th IEEE Power Systems Computations Conference, 2014.
 C. G. Petra, Olaf Schenk, Miles Lubin, Klaus Gaertner. An augmented incomplete factorization approach for computing the Schur complement in stochastic optimization. SIAM J. Sci. Comput., 362, pages C139C162, 2014. DOI
 M. Lubin, K. Martin, C.G. Petra, and Burhaneddin Sandikic. On parallelizing dual decomposition in stochastic integer programming. Operations Research Letters 41(3), pages 252258, 2013. DOI
 M. Lubin, C. G. Petra, M. Anitescu, and V. Zavala. Scalable Stochastic Optimization of Complex Energy Systems. In Proceedings of 2011 International Conference for High Performance Computing, Networking, Storage and Analysis (SC '11), pages 64:164:10. DOI
 M. Lubin, J. A. J. Hall, C. G. Petra, and M. Anitescu. Parallel distributedmemory simplex for largescale stochastic LP problems., Computational Optimization and Applications 55(3), pages 571596, 2013. CoinOR INFORMS 2013 Cup winner + 2013 COAP Best Paper. DOI
 M. Lubin, C. G. Petra, M. Anitescu. On the parallel solution of dense saddlepoint linear systems arising in stochastic programming. Optimization Methods and Software, Volume 27, Number 45, Pages 845864, 2012.
 C. G. Petra, M. Anitescu. A preconditioning technique for Schur complement systems arising in stochastic optimization. Computational Optimization and Applications, Pages 315344, Volume 52, Issue 2, 2012.
 A. Draganescu, C. G. Petra. Multigrid preconditioning of linear systems for interior point methods applied to a class of boundconstrained control problems. SIAM Journal on Numerical Analysis, Volume 50, Number 1, Pages 328353, 2012.
 S. AlHomidan, M. M. Alshahrani, C. G. Petra, F. A. Potra. Minimal Condition Number for Positive Definite Hankel Matrices using Semidefinite Programming. Linear Algebra and Its Applications, Volume 433, Issue 6, Pages 11011109, November 2010.
 F. Gurtuna, C. G. Petra, F. A. Potra, O. Schevchenko, A. Vancea. CorrectorPredictor Methods for sufficient linear complementarity problems. Computational Optimization and Applications, Volume 48, Issue 3, Pages 453485, April 2011. COAP Best Paper 2011  Honorable mention.
 C. G. Petra, B. Gavrea, M. Anitescu, F. A. Potra. A computational study on the use of an optimization based method in the simulation of large multibody systems. Optimization Methods and Software, Volume 24, Issue 6, Pages 871894, 2009.
Technical reports
 S. Peles, K. Perumalla, M. Alam, A. Mancinelli, R. C. Rutherford, J. Ryan, C. G. Petra, Porting the Nonlinear Optimization Library HiOp to AcceleratorBased Hardware Architectures, submitted, 2021.
 T. Hartland, C. G. Petra, N. Petra, J. Wang, Bound Constrained Partial Differential Equation Inverse Problem Solution by the SemiSmooth Newton Method, Technical Report LLNLTR819385, 2021.
 C. G. Petra, N. Chiang, J. Wang, "HiOp  User manual", Tech Report LLNLSM743591, 20182022, Lawrence Livermore National Laboratory.
 M. Anitescu, C. G. Petra. HigherOrder Confidence Intervals for Stochastic Programming using Bootstrapping, 2012, Tech Report ANL/MCSP19641011. Argonne National Laboratory.
 R. Serban, C. G. Petra. User Documentation for IDAS v1.0.0, 2008, Report UCRLSM234051, Lawrence Livermore National Laboratory.
Selected talks
 SCACOPF using nonlinear nonconvex optimization and highperformance computing, INFORMS Annual Meeting (2019), ARPAE GridOptimization Outreach Event (2020), Energy Systems and Optimization Workshop  Georgia Tech (2020)
 Parallel Structured QuasiNewton Methods for Material Design, SIAM Conference on Optimization (2017), SIAM Student Chapter, UC Davis (2017)
 Optimization and Design of Complex Engineering Systems using HighPerformance Computing, SIAMCSE (2017).
 Scalable stochastic optimization of complex energy systems on highperformance computers, Zuse Institut Berlin (2016)
 Modelling and solving SCACOPF problems in parallel, FERC Technical Conference on Increasing Market and Planning Efficiency through Improved Software (2016)
 Optimizationbased parameter estimation of dynamic power grid systems, SIAM UQ (2016).
 Scalable optimization of complex energy systems using highperformance computing, Joint Mathematics Meeting, SIAM Parallel Processing (2016)
 Parallel algebraic modelling for stochastic optimization in Julia, Platform for Advanced Scientific Computing Conference (2015)
 On the role of wind correlation in the economic dispatch of power grid systems, SIAM CSE (2015)
 Global Security Gold Award, Lawrence Livermore National Laboratory, 2020.
 First place in Division 1, 2, 3, and 4 of the ARPAE GridOptimization Competition Challenge 1 (team name gollnlp) 20182020. Kudos page from ARPAE.
 COAP 2013 Best Paper Prize
 DOE Incite Award 20122013, 24 million core hours
 2013 COINOR INFORMS Cup
 Honorable mention  COAP 2011 Best Paper Prize