Picture of Emil Constantinescu

Emil Mihai
Constantinescu
emconsta[at]mcs.anl.gov
Office #: 2151

Computational Mathematician
Mathematics and Computer Science
Argonne National Laboratory

Fellow of the Computation Institute
University of Chicago


Homepage

Research

- Time stepping
- Uncertainty
- AMR
Publications
ANL Stuff

@ARTICLE{Marras_2016a,
      author = {S. Marras, M.A. Kopera, E.M. Constantinescu, J. Suckale, and F.X. Giraldo},
      title = {A continuous/discontinuous {G}alerkin solution of the shallow water equations with dynamic viscosity, high-order wetting and drying, and implicit time integration},
      journal = {Advances in Water Resources, Submitted},
      year = {2016}
}

@ARTICLE{Tartakovsky_S2015a,
      author = {P. Wang and D. Barajas-Solano and E.M. Constantinescu and S. Abhyankar and D. Ghosh and B. Smith and Z. Huang and A. Tartakovsky},
      title = {Probabilistic density function method for stochastic {ODE}s of power systems with uncertain power input},
      volume= {3},
      number= {1},
      pages= {873-896},
      DOI = {10.1137/130940050},
      journal = {SIAM/ASA Journal on Uncertainty Quantification, in print},
      year = {2015}
}

@ARTICLE{Hong_2016a,
      author = {H. Zhang and S.S. Abhyankar and E.M. Constantinescu and M. Anitescu},
      title = {Discrete adjoint sensitivity analysis of power system dynamics},
      journal = {IEEE Transactions on Circuits and Systems I: Regular Papers, In press},
      year = {2016}
}

@ARTICLE{Petra_2016a,
      author = {Noemi Petra and Cosmin G. Petra and Zheng Zhang and Emil M. Constantinescu and Mihai Anitescu},
      title = {A Bayesian approach for parameter estimation with uncertainty for dynamic power systems},
      journal = {IEEE Transactions on Power Systems, In press},
      year = {2016}
}

@ARTICLE{Li_2015a,
      author = {N. Li and C. Uckun and E.M. Constantinescu and J. Birge and K.W. Hedman and A. Botterud},
      title = {Flexible operation of batteries in power system scheduling with renewable energy},
      volume= {},
      number= {},
      pages= {},
      DOI = {10.1109/TSTE.2015.2497470},
      journal = {IEEE Transactions on Sustainable Energy, in print},
      year = {2015}
}

@ARTICLE{Bessac_2016a,
      author = {J. Bessac and E.M. Constantinescu and M. Anitescu},
      title = {Stochastic simulation of predictive space-time scenarios of wind speed using observations and physical models},
      journal = {Annals of Applied Statistics, In press},
      volume = {},
      pages = {},
      number = {ANL/MCS-P5432-1015},
      doi = {},
      year = {2015}
}

@ARTICLE{Ghosh_2015b,
      author = {D. Ghosh and E.M. Constantinescu},
      title = {Semi-implicit time integration of atmospheric flows with characteristic-based flux partitioning},
      journal = {SIAM Journal on Scientific Computing (SISC)},
      volume = {38},
      pages = {A1848-A1875},
      number = {3},
      doi = {10.1137/15M1044369},
      year = {2016}
}

@ARTICLE{Ghosh_2015a,
      author = {D. Ghosh and E.M. Constantinescu},
      title = {A well-balanced conservative finite-difference algorithm for atmospheric flows},
      journal = {AIAA, Accepted},
      volume = {},
      pages = {},
      number = {},
      doi = {},
      year = {2015}
}

@ARTICLE{Abhyankar_2015a,
      author = {S. Abhyankar and E.M. Constantinescu and B. Smith and A.J. Flueck and D.A. Maldonado},
      title = {Acceleration of dynamic simulations using parallel {N}ewton-{GMRES}-{S}chwarz methods},
      journal = {Transactions on Smart Grid Special Issue on High Performance Computing (HPC) Applications for a More Resilient and Efficient Power Grid, Submitted},
      volume = {},
      pages = {},
      number = {},
      doi = {},
      year = {2016}
}

@TechReport{Cappello_TR2015,
      author = {F. Cappello and E.M. Constantinescu and P.D. Hovland and T. Peterka and C.L. Phillips and M. Snir and S.M. Wild},
      title = {Improving the Trust in Results of Numerical Simulations and Scientific Data Analytics},
      intitution = {Argonne National Laboratory},
      pages = {19},
      number = {ANL/MCS-TM-352},
      month = {April},
      year = {2015}
}

@ARTICLE{Bilionis_A2015a,
      author = {I. Bilionis and B.D. Drewniak and E.M. Constantinescu},
      title = {Crop Physiology Calibration in the {CLM}},
      journal = {Geoscientific Model Development},
      volume = {8},
      pages = {1071--1083},
      number = {4},
      doi = {10.5194/gmd-8-1071-2015},
      year = {2015}
}

@ARTICLE{Bilionis_S2014a,
      author = {I. Bilionis and E.M. Constantinescu and M. Anitescu},
      title = {Data-driven model for solar irradiation based on satellite observations},
      volume= {110},
      DOI = {10.1016/j.solener.2014.09.009},
      journal = {Solar Energy},
      year = {2014}
}

@incollection{Ghosh_P2014a,
     author = {D. Ghosh and E.M. Constantinescu},
     title = {Nonlinear Compact Finite-Difference Schemes with Semi-Implicit Time Stepping},
     booktitle={Spectral and High Order Methods for Partial Differential Equations ICOSAHOM 2014},
     volume={106},
     series={Lecture Notes in Computational Science and Engineering},
     editor={Kirby, Robert M. and Berzins, Martin and Hesthaven, Jan S.},
     doi={10.1007/978-3-319-19800-2_20},
     url={http://dx.doi.org/10.1007/978-3-319-19800-2_20},
     publisher={Springer International Publishing},
     year={2015}
}

@ARTICLE{Ghosh_S2014a,
      author = {D. Ghosh and E.M. Constantinescu and J. Brown},
      title = {Efficient implementation of nonlinear compact schemes on massively parallel platforms},
      journal = {SIAM Journal on Scientific Computing (SISC)},
      volume= {37},
      pages={C354--C383},
      number = {3},
      year = {2015}
}

 

@TechReport{Zhang_TR2016a,
      author = {Hong Zhang and S.S. Abhyankar and E.M. Constantinescu and M. Anitescu},
      title = {Efficient adjoint computation of hybrid systems of differential algebraic equations with applications in power systems},
     Institution= {Argonne National Laboratory},
      year = {2016}
}

@TechReport{Ghosh_TR2014a,
      author = {D. Ghosh and E.M. Constantinescu and J. Brown},
      title = {Scalable Nonlinear Compact Schemes},
     Institution= {Argonne National Laboratory},
      year = {2014}
}

@ARTICLE{Constantinescu_2015a,
      author = {E.M. Constantinescu},
      title = {Generalizing global error estimation for ordinary differential equations by using coupled time-stepping methods},
      journal = {Submitted},
      year = {2016}
}

@ARTICLE{Giraldo_2013,
      author = {F.X. Giraldo and J.F. Kelly and E.M. Constantinescu},
      title = {Implicit-explicit formulations of a three-dimensional nonhydrostatic unified model of the atmosphere ({NUMA})},
      journal = {SIAM Journal on Scientific Computing},
      volume= {35},
      pages={B1162--B1194},
      number = {5},
      year = {2013}
}

@inproceedings{Abhyankar_P2013,
      author = {Abhyankar, S. and Smith, B. and Constantinescu, E.},
      title = {Evaluation of overlapping restricted additive Schwarz preconditioning for parallel solution of very large power flow problems},
      booktitle = {Proceedings of the 3rd International Workshop on High Performance Computing, Networking and Analytics for the Power Grid},
      pages={5:1--5:8},
      series = {HiPCNA-PG '13},
      doi = {10.1145/2536780.2536784},
      publisher={ACM},
      year = {2013}
}

@inproceedings{, title={Evaluation of overlapping restricted additive Schwarz preconditioning for parallel solution of very large power flow problems}, author={Abhyankar, Shrirang and Smith, Barry and Constantinescu, Emil}, booktitle={Proceedings of the 3rd International Workshop on High Performance Computing, Networking and Analytics for the Power Grid}, pages={5}, year={2013}, organization={ACM} }

@article{KeyesMcInnesWoodwardEtAl13,
      title = {Multiphysics Simulations: Challenges and Opportunities},
      author = {David E. Keyes and Lois Curfman McInnes and Carol Woodward and William Gropp and Eric Myra and Michael Pernice and John Bell and Jed Brown and Alain Clo and Jeffrey Connors and Emil Constantinescu and Don Estep and Kate Evans and Charbel Farhat and Ammar Hakim and Glenn Hammond and Glen Hansen and Judith Hill and Tobin Isaac and Xiangmin Jiao and Kirk Jordan and Dinesh Kaushik and Efthimios Kaxiras and Alice Koniges and Kihwan Lee and Aaron Lott and Qiming Lu and John Magerlein and Reed Maxwell and Michael McCourt and Miriam Mehl and Roger Pawlowski and Amanda Peters Randles and Daniel Reynolds and Beatrice Rivi\`{e}re and Ulrich R\"{u}de and Tim Scheibe and John Shadid and Brendan Sheehan and Mark Shephard and Andrew Siegel and Barry Smith and Xianzhu Tang and Cian Wilson and Barbara Wohlmuth},
       journal = {International Journal of High Performance Computing Applications},
       month = {Feb},
       year = {2013},
       volume = {27},
       number = {1},
       pages = {4--83},
       doi = {10.1177/1094342012468181},
       abstract = {We consider multiphysics applications from algorithmic and architectural perspectives, where ``algorithmic'' includes both mathematical analysis and computational complexity and ``architectural'' includes both software and hardware environments. Many diverse multiphysics applications can be reduced, en route to their computational simulation, to a common algebraic coupling paradigm. Mathematical analysis of multiphysics coupling in this form is not always practical for realistic applications, but model problems representative of applications discussed herein can provide insight. A variety of software frameworks for multiphysics applications have been constructed and refined within disciplinary communities and executed on leading-edge computer systems. We examine several of these, expose some commonalities among them, and attempt to extrapolate best practices to future systems. From our study, we summarize challenges and forecast opportunities.}
}

@ARTICLE{Anitescu_A2014,
      author = {M. Anitescu and X. Zeng and E.M. Constantinescu},
      title = {A low-memory approach for best-state estimation of hidden {M}arkov models with model error},
      journal = {SIAM Journal on Numerical Analysis (SINUM)},
      volume = {52},
      pages = {468-495},
      number = {1},
      doi = {10.1137/120870451},
      year = {2014}
}

 

@ARTICLE{Zeng_S2012,
      author = {X. Zeng and B.D. Drewniak and E.M. Constantinescu},
      title = {Calibration of the crop model in the {C}ommunity {L}and {M}odel},
      journal = {Geoscientific Model Development, submitted},
      year = {2013},
      volume = 1,
      number = 6,
      pages = "379--398",
      doi = "10.5194/gmdd-6-379-2013"
}


@ARTICLE{Salazar_2013,
      author = {J.M. Salazar and U. Diwekar and E.M. Constantinescu and V Zavala},
      title = {Stochastic Optimization Approach to Water Management in Cooling-Constrained Power Plants},
      journal = {Applied Energy},
      volume = 112,
      pages = "12--24",
      year = {2013}
}


@TECHREPORT{Keyes_TR2012,
      author = {D.E. Keyes and L.C. McInnes and C. Woodward and W.D. Gropp and E. Myra and M. Pernice and J. Bell and J. Brown and A. Clo and J. Connors and E. Constantinescu and D. Estep and K. Evans and C. Farhat and A. Hakim and G. Hammond and G. Hansen and J. Hill and T. Isaac and X. Jiao and K. Jordan and D. Kaushik and E. Kaxiras and A. Koniges and K. Lee and A. Lott and Q. Lu and J. Magerlein and R. Maxwell and M. McCourt and M. Mehl and R. Pawlowski and A. Peters and D. Reynolds and B. Riviere and U. R\"{u}de and T. Scheibe and J. Shadid and B. Sheehan and M. Shephard and A. Siegel and B. Smith and X. Tang and C. Wilson and B. Wohlmuth},
      title = {{Multiphysics Simulations: Challenges and Opportunities}},
      institution = {Argonne National Laboratory},
      number = {ANL/MCS-TM-321},
      note = {{Workshop Report, Park City, Utah, July 30 - August 6, 2011, sponsored by the Institute for Computing in Science (ICiS)}},
      url = {http://www.ipd.anl.gov/anlpubs/2012/01/72183.pdf},
      year = {2012}
}


@TECHREPORT{Smith_TR2012a,
      author ={Barry Smith and Lois Curfman McInnes and Emil Constantinescu and Mark Adams and Satish Balay and Jed Brown and Matthew Knepley and Hong Zhang},
      title = {{PETSc's} Software Strategy for the Design Space of Composable Extreme-Scale Solvers},
      number = {ANL/MCS-P2059-0312},
      note = {{DOE} Exascale Research Conference, April 16-18, 2012, Portland, OR},
      year = {2012}
}


@ARTICLE{Constantinescu_A2011c,
      author = {A. Sandu and E.M. Constantinescu and G.R. Carmichael,andTianfeng Chai,and D. Daescu and J Seinfeld},
      title = {Ensemble Methods for Dynamic Data Assimilation of Chemical Observations in Atmospheric Models},
      journal = {Journal of Algorithms \& Computational Technology},
      volume = {5},
      pages = {4},
      year = {2011}
}

@Article{ Constantinescu_S2011b,
      author = "E.M. Constantinescu and M. Anitescu",
      title = "Physics-based covariance models for {G}aussian processes with multiple outputs",
      journal = "International Journal for Uncertainty Quantification",
      volume ={3},
      number = {1},
      pages = {47--71},
      year = {2013}
}

@Article{ Constantinescu_A2007a,
      author = "E.M. Constantinescu and A. Sandu and T. Chai and G.R. Carmichael",
      title = "Assessment of ensemble-based chemical data assimilation in an idealized setting",
      volume = 41,
      number = 1,
      pages = "18--36",
      journal = "Atmospheric Environment",
      year = "2007",
      doi = "10.1016/j.atmosenv.2006.08.006 "
}
@Article{ Constantinescu_A2013,
      author = "E.M. Constantinescu and A. Sandu",
      title = "Extrapolated multirate methods for differential equations with multiple time scales",
      journal = "Journal of Scientific Computing",
      year = "2013",
      pages="28--44",
      volume = "56",
      number = "1",
}

@Article{ Constantinescu_A2007b,
      author = "E.M. Constantinescu and A. Sandu and T. Chai and G.R. Carmichael",
      title = "Ensemble-based chemical data assimilation {I}: {G}eneral approach",
      year = "2007",
      journal = "Quarterly Journal of Royal Meteorological Society",
      pages = "1229--1243",
      volume = "133",
      number = "626",
      month = "July",
      issn = "0035-9009",
      doi = "10.1002/qj.76"
}

@Article{ Constantinescu_A2007c,
      author = "E.M. Constantinescu and A. Sandu and T. Chai and G.R. Carmichael",
      title = "Ensemble-based chemical data assimilation {II}: {C}ovariance localization",
      year = "2007",
      journal = "Quarterly Journal of Royal Meteorological Society",
      pages = "1245--1256",
      volume = "133",
      number = "626",
      month = "July",
      issn = "0035-9009",
      doi = "10.1002/qj.77"
}

@Article{ Constantinescu_A2007d,
      author = "E.M. Constantinescu and T. Chai and A. Sandu and G.R. Carmichael",
      title = "Autoregressive models of background errors for chemical data assimilation",
      journal = "Journal of Geophysical Research",
      year = "2007",
      pages = "D12309",
      volume = "112",
      doi = "10.1029/2006JD008103"
}

@Article{ Constantinescu_A2007e,
      author = "E.M. Constantinescu and A. Sandu",
      title = "Multirate timestepping methods for hyperbolic conservation laws",
      journal = "Journal of Scientific Computing",
      year = "2007",
      pages = " 239--278",
      volume = "33",
      number = "3",
      month = dec,
      doi = "10.1007/s10915-007-9151-y"
}

@Article{ Sandu_A2007,
      author = "A. Sandu and E.M. Constantinescu",
      title = "Multirate explicit {A}dams methods for time integration of conservation laws",
      journal = "Journal of Scientific Computing",
      volume = "38",
      pages = "229--249",
      number = "2",
      year = "2009",
      doi = "10.1007/s10915-008-9235-3"
}

@Article{ Bessa_S2012,
      author = "R.J. Bessa and V. Miranda and A. Botterud and J. Wang, and E.M. Constantinescu",
      title = "Time Adaptive Conditional Kernel Density Estimation for Wind Power Forecasting",
      journal = "To appear in IEEE Transactions on Sustainable Energy (Special Wind Energy issue)",
      volume={3},
      number={4},
      pages={660-669},
      doi={10.1109/TSTE.2012.2200302},     
      year = "2012"
}


@Article{ Constantinescu_A2008a,
      author = "E.M. Constantinescu and A. Sandu and G.R. Carmichael",
      title = "Modeling atmospheric chemistry and transport with dynamic adaptive resolution",
      journal = "Computational Geosciences",
      year = "2008",
      doi = "10.1007/s10596-007-9065-7",
      pages = "133--151",
      volume = "12",
      number = "2",
      abstract = "We discuss an adaptive resolution system for modeling regional air pollution based on the chemical transport model STEM. The grid adaptivity is implemented using the generic adaptive mesh refinement tool Paramesh, which enables the grid management operations while harnessing the power of parallel computers. The computational algorithm is based on a decomposition of the domain, with the solution in different subdomains being computed with different spatial resolutions. Various refinement criteria that adaptively control the fine grid placement are analyzed to maximize the solution accuracy while maintaining an acceptable computational cost. Numerical experiments in a large-scale parallel setting (~0.5 billion variables) confirm that adaptive resolution, based on a well-chosen refinement criterion, leads to the decrease in spatial error with an acceptable increase in computational time. Fully dynamic grid adaptivity for air quality models is relatively new. We extend previous work on chemical and transport modeling by using dynamically adaptive grid resolution. Advantages and shortcomings of the present approach are also discussed."
}

@Article{ Constantinescu_S2008b,
      author = "E.M. Constantinescu and A. Sandu",
      title = "Extrapolated implicit-explicit time stepping",
      journal = "SIAM Journal of Scientific Computing",
      pages = "4452--4477",
      volume = "31",
      number = "6",
      year = "2010",
      doi = "10.1137/080732833"
}


@Article{ Zhang_A2008,
      title = "An Adjoint Sensitivity Analysis and {4D-Var} Data Assimilation Study of {T}exas Air Quality",
      author = "L. Zhang and E.M. Constantinescu and A. Sandu and Y. Tang and T. Chai and G.R. Carmichael and D. Byun and E. Olaguer",
      journal = "Atmospheric Environment (ACM Issue)",
      year = "2008",
      pages = "5787--5804 ",
      volume = "42",
      number = "23",
      abstract = "In this paper, we discuss the theory of adjoint sensitivity analysis and the method of 4D-Var data assimilation in the context of the Sulfur Transport Eulerian Model (STEM). The STEM atmospheric Chemical Transport Model (CTM) is used to perform adjoint sensitivity analysis and data assimilation over the State of Texas. We first demonstrate the use of adjoint sensitivity analysis for a receptor located at ground level in the Dallas Fort Worth (DFW) area. Simulations are carried out for three 36-h intervals in July 2004. One set of simulations focuses on a passive tracer, and illustrates the influence of meteorological conditions. The other results show the areas of influence associated with DFW ground level ozone, i.e. the areas where changes in precursors (O3, NO2, and HCHO) have the maximum impact on DFW ozone. Next, we employ data assimilation to optimize initial conditions of chemical fields and ground level emissions. We optimize the initial conditions for two episodes on 1 and 16 July 2004. Data assimilation makes use of AirNow ground level observations (for both episodes) and SCHIAMACHY NO2 and HCHO observations from ENVISAT (for the 16 July episode). The re-analyzed chemical fields show considerable improved agreement with AirNow observations for non-initial conditions. We also perform inverse modeling of ground level emissions using data assimilation under an additional smoothness constraint. The results indicate higher NO2 emission levels than in the current emission inventory in the DFW area, and lower emission levels in eastern Texas. The formaldehyde emissions are found to be larger than reported in a localized area near the Gulf Coast, and about at the reported level elsewhere. While the results obtained with the current state-of-the-art tools can help guide tuning of emission inventories, better constraints on the inverse problem are needed to obtain more rigorous quantitative estimates.",
      doi = "10.1016/j.atmosenv.2008.03.048 "
}

@Article{ Carmichael_A2008,
      author = "G.R. Carmichael and A. Sandu and T. Chai and D.N. Daescu and E.M. Constantinescu and Y. Tang",
      title = "Predicting air-quality: {I}mprovements through advanced methods to integrate models and measurements",
      journal = "Journal of Computational Physics",
      year = "2008",
      OPTkey = "",
      OPTvolume = "227",
      OPTnumber = "7",
      OPTpages = "3540-3571",
      OPTmonth = "",
      OPTnote = "",
      OPTannote = "",
      doi = "10.1016/j.jcp.2007.02.024"
}

@Article{ Constantinescu_A2009b,
      title = "On the order of general linear methods",
      author = "E.M. Constantinescu",
      journal = "Applied Mathematics Letters",
      year = "2009",
      doi = "10.1016/j.aml.2008.12.005",
      pages = "1425--1428 ",
      volume = "22",
      number = "9"
}


@Article{ Zavala_S2009,
     title = "On-line economic optimization of energy systems using weather forecast information",
     author = "V. Zavala and E.M. Constantinescu and T. Krause and M. Anitescu",
     doi = "10.1016/j.jprocont.2009.07.004" ,
     journal = "Journal of Process Control",
     pages = "1725--1736 ",
      volume = "19",
      number = "10"
     year = "2009"
}


@TechReport{ Zavala_TR2009,
     title = "Exploiting Weather Forecast Information in the Operation of Integrated Energy Systems",
     author = "V. Zavala and E.M. Constantinescu and T. Krause and M. Anitescu",
     institution = "Argonne National Laboratory, Mathematics and Computer Science Division Technical Memorandum",
     number = "ANL/MCS-TM-305",
     year = "2009"
}


@TechReport{ Constantinescu_TR2009c,
     title = "Unit Commitment with Wind Power Generation: {I}ntegrating Wind Forecast Uncertainty and Stochastic Programming",
     author = "E.M. Constantinescu and V. Zavala and M. Rocklin and S. Lee and M. Anitescu",
     institution = "Argonne National Laboratory, Mathematics and Computer Science Division Technical Memorandum",
     number = "ANL/MCS-TM-309",
     year = "2009"
}

 

@Article{ Constantinescu_A2011a,
     title = "A Computational Framework for Uncertainty Quantification and Stochastic Optimization in Unit Commitment with Wind Power Generation",
     author = "E.M. Constantinescu and V. Zavala and M. Rocklin and S. Lee and M. Anitescu",
     journal = "IEEE Transactions on Power Systems",
     volume = "26",
     pages = "431-441",
     number = "1",
     year = "2011",
     doi = "10.1109/TPWRS.2010.2048133"
}

 

@TechReport{ Constantinescu_TR2009a,
     author = "E.M. Constantinescu and A. Sandu",
     title = "Optimal explicit strong-stability-preserving general linear methods: {C}omplete Results",
     institution = "Argonne National Laboratory, Mathematics and Computer Science Division Technical Memorandum",
     year = "2009",
     number = "ANL/MCS-TM-304"
}

@Article{ Constantinescu_P2008d,
      author = "E.M. Constantinescu and A. Sandu",
      title = "Optimal explicit strong-stability-preserving general linear methods",
      journal = "In preparation",
      year = "2008"
}

@Article{ Constantinescu_A2010b,
     author = "E.M. Constantinescu and A. Sandu",
      title = "Optimal explicit strong-stability-preserving general linear methods",
      journal = "SIAM Journal of Scientific Computing",
     pages = "3130-3150",
      volume = "32",
      number = "5"
      doi = "10.1137/090766206",
      year = "2010"
}


@TechReport{ Constantinescu_TR2006a,
      author = "E.M. Constantinescu and A. Sandu and T. Chai and G.R. Carmichael",
      title = "Ensemble-based chemical data assimilation {I}: {A}n idealized setting",
      institution = "Computer Science, Virginia Tech",
      year = "2006",
      OPTkey = "",
      OPTtype = "",
      number = "TR-06-06",
      OPTaddress = "",
      month = "April",
      OPTnote = "",
      OPTannote = ""
}

@TechReport{ Constantinescu_TR2006b,
      author = "E.M. Constantinescu and A. Sandu and T. Chai and G.R. Carmichael",
      title = "Ensemble-based chemical data assimilation {II}: {R}eal observations",
      institution = "Computer Science, Virginia Tech",
      year = "2006",
      OPTkey = "",
      OPTtype = "",
      number = "TR-06-07",
      OPTaddress = "",
      month = "April",
      OPTnote = "",
      OPTannote = ""
}

@TechReport{ Constantinescu_TR2006c,
      author = "E.M. Constantinescu and A. Sandu and T. Chai and G.R. Carmichael",
      title = "Ensemble-based chemical data assimilation {III}: {F}ilter localization",
      institution = "Computer Science, Virginia Tech",
      year = "2006",
      OPTkey = "",
      OPTtype = "",
      number = "TR-06-08",
      OPTaddress = "",
      month = "April",
      OPTnote = "",
      OPTannote = ""
}

@TechReport{ Constantinescu_TR2006d,
      author = "E.M. Constantinescu and A. Sandu",
      title = "Multirate timestepping methods for hyperbolic conservation laws",
      institution = "Computer Science, Virginia Tech",
      year = "2006",
      OPTkey = "",
      OPTtype = "",
      number = "TR-06-15",
      OPTaddress = "",
      month = "June",
      OPTnote = "",
      OPTannote = ""
}

@TechReport{ Constantinescu_TR2006e,
      author = "E.M. Constantinescu and T. Chai and A. Sandu and G.R. Carmichael",
      title = "Autoregressive models of background errors for chemical data assimilation",
      institution = "Computer Science, Virginia Tech",
      year = "2006",
      OPTkey = "",
      OPTtype = "",
      number = "TR-06-22",
      OPTaddress = "",
      month = "October",
      OPTnote = "",
      OPTannote = ""
}

@TechReport{ Constantinescu_TR2007a,
      author = "E.M. Constantinescu and A. Sandu",
      title = "Update on multirate timestepping methods for hyperbolic conservation laws",
      institution = "Computer Science, Virginia Tech",
      year = "2007",
      OPTkey = "",
      OPTtype = "",
      number = "TR-07-12(955)",
      OPTaddress = "",
      month = "March",
      OPTnote = "",
      OPTannote = ""
}

@TechReport{ Constantinescu_TR2007b,
      author = "A. Sandu and E.M. Constantinescu",
      title = "Multirate explicit {A}dams methods for time integration of conservation laws",
      institution = "Computer Science, Virginia Tech",
      year = "2007",
      OPTkey = "",
      OPTtype = "",
      number = "TR-07-30(989)",
      OPTaddress = "",
      month = "August",
      OPTnote = "",
      OPTannote = "",
      url = "http://eprints.cs.vt.edu/archive/00000989/01/mradams.pdf"
}

@TechReport{ Constantinescu_TR2008a,
      author = "E.M. Constantinescu and A. Sandu",
      title = "On Extrapolated Multirate Methods",
      institution = "Computer Science, Virginia Tech",
      year = "2008",
      OPTkey = "",
      OPTtype = "",
      number = "TR-08-12",
      OPTaddress = "",
      OPTnote = "",
      OPTannote = "",
      url = "http://eprints.cs.vt.edu"
}

@TechReport{ Constantinescu_TR2008b,
      author = "E.M. Constantinescu and A. Sandu",
      title = "Achieving Very High Order for Implicit Explicit Time Stepping: {E}xtrapolation Methods",
      institution = "Computer Science, Virginia Tech, \url{http://eprints.cs.vt.edu/archive/00001037/01/ExImex.pdf}",
      year = "2008",
      OPTkey = "",
      OPTtype = "",
      number = "TR-08-13",
      OPTaddress = "",
      OPTnote = "",
      OPTannote = "",
      url = "http://eprints.cs.vt.edu/archive/00001037/01/ExImex.pdf"
}

@TechReport{ Constantinescu_TR2008c,
      author = "E.M. Constantinescu",
      title = "On the order of general linear methods",
      institution = "Argonne National Laboratory",
      year = "2008",
      month = "October",
      number = "ANL/MCS-P1555-1008"
}

@TechReport{ Constantinescu_TR2009b,
      author = "E.M. Constantinescu and A. Sandu",
      title = "Achieving Very High Order for Implicit Explicit Time Stepping: {E}xtrapolation Methods",
      institution = "Argonne National Laboratory, Mathematics and Computer Science Division Technical Memorandum, \mbox{\url{http://www.mcs.anl.gov/uploads/cels/papers/TM-306.pdf}}",
      year = "2009",
      OPTkey = "",
      OPTtype = "",
      number = "ANL/MCS-TM-306",
      OPTaddress = "",
      OPTnote = "",
      OPTannote = "",
      url = "http://www.mcs.anl.gov/uploads/cels/papers/TM-306.pdf",
      month = "April"
}
@InProceedings{ Sandu_PA2004,
      author = "A. Sandu and C. Belwal and E.M. Constantinescu",
      title = "Parallel Adaptive Simulations of Regional Air Quality",
      year = "2004",
      organization = "SIAM Conference on Parallel Processing for Scientific Computing"
}

@InProceedings{ Belwal_PA2004,
      author = "C. Belwal and A. Sandu and E.M. Constantinescu",
      title = "Adaptive Resolution Modeling of Regional Air Quality",
      booktitle = "Proceedings of the 2004 ACM",
      pages = "235--239",
      year = "2004",
      organization = "ACM Symposium on Applied Computing"
}

@InProceedings{ Constantinescu_PA2005a,
      author = "E.M. Constantinescu and W. Liao and A. Sandu",
      title = "Mesh Refinement Strategies in Air Quality Modeling",
      booktitle = "High Performance Computing Symposium (HPC 2005)",
      pages = "158--163",
      year = "2005",
      organization = "High Performance Computing Symposium"
}

@InProceedings{ Constantinescu_PA2005b,
      author = "E.M. Constantinescu and A. Sandu",
      title = "On Adaptive Mesh Refinement for Atmospheric Pollution Models",
      booktitle = "Lecture Notes in Computer Science",
      pages = "798--806",
      year = "2005",
      volume = "3515",
      organization = "``International Conference on Computational Science''"
}

@InProceedings{ Sandu_PA2005,
      author = "A. Sandu and E.M. Constantinescu and W. Liao and G.R. Carmichael and T. Chai and J.H. Seinfeld and D.N. Daescu",
      title = "Ensemble Filter Data Assimilation for Atmospheric Chemical and Transport Models",
      pages = "648--656",
      year = "2005",
      organization = "International Conference on Computational Science"
}

@InProceedings{ Constantinescu_PA2006a,
      author = "D. Negrut and M. Anitescu and A. El-Azab and S. Benson and E.M. Constantinescu and P. Zapol and T. Heyn",
      title = "A Real-Space Parallel Optimization Model Reduction Approach for Electronic Structure Computation in Large Nanostructures Using Orbital-Free Density Functional Theory",
      booktitle = "Proceedings of IMECE 2006-15740",
      year = "2006",
      organization = "ASME International Mechanical Engineering Congress and Exposition"
}

@InProceedings{ Constantinescu_PA2006b,
      author = "E.M. Constantinescu and A. Sandu and T. Chai and G.R. Carmichael",
      title = "Localized ensemble {K}alman data assimilation for atmospheric chemical transport models",
      booktitle = "Lecture Notes in Computer Science",
      pages = "-",
      year = "2006",
      volume = "-",
      organization = "``International Conference on Computational Science''"
}

@InProceedings{ Sandu_PA2008a,
      title = "On Extrapolated multirate numerical integration methods",
      series = "Springer Mathematics in Industry - ECMI 2008",
      author = "E.M. Constantinescu and A. Sandu",
      location = "University College London",
      pages = "341-347",
      volume = "15",
      year = "2010",
      booktitle = "ECMI 2008",
      publisher = "Springer"
}
 
@InProceedings{ Sandu_PA2007Pa,
      author = "A. Sandu and E.M. Constantinescu and G.R. Carmichael and T. Chai and J.H. Seinfeld and D.N. Daescu",
      title = "Localized Ensemble Kalman Dynamic Data Assimilation for Atmospheric Chemistry",
      booktitle = "International Conference on Computational Science (1)",
      year = "2007",
      pages = "1018--1025",
      ee = "http://dx.doi.org/10.1007/978-3-540-72584-8_134",
      crossref = "DBLP:conf/iccS/2007-1",
      bibsource = "DBLP, http://dblp.uni-trier.de"
}

@Misc{ Constantinescu_PA2007a,
      title = "4D-Var computational tools for the assimilation of observations in chemical transport models",
      booktitle = "SIAM Conference on Computational Science and Engineering (CSE 2007)",
      author = "E.M. Constantinescu and A. Sandu",
      location = "Costa Mesa, CA",
      month = feb,
      year = "2007"
}

@Misc{ Constantinescu_PA2007b,
      title = "Strong stability preserving multirate schemes for hyperbolic conservation laws",
      booktitle = "SIAM Conference on Computational Science and Engineering (CSE 2007)",
      author = "E.M. Constantinescu and A. Sandu",
      location = "Costa Mesa, CA",
      month = feb,
      year = "2007"
}

@InProceedings{ Cioaca_P2011,
      author = "A. Cioaca and V. Zavala and E.M. Constantinescu",
      title = "Adjoint Sensitivity Analysis for Numerical Weather Prediction: Applications to Power Grid Optimization",
      booktitle = "1st International Workshop on High Performance Computing, Networking and Analytics for the Power Grid; Preprint ANL/MCS-P1928-0911",
      year = "2011",
      volume = "Submitted"
}

@InProceedings{ Constantinescu_PA2009a,
      author = "E.M. Constantinescu and A. Sandu",
      title = "Explicit time stepping methods with high stage order and monotonicity properties",
      booktitle = "Lecture Notes in Computer Science",
      pages = "-",
      year = "2009",
      volume = "-",
      organization = "International Conference on Computational Science"
}

@InProceedings{ Constantinescu_PA2009b,
      author = "A. Sandu and E.M. Constantinescu ",
      title = "Multirate Time Discretizations for Hyperbolic Partial Differential Equations",
      booktitle = "AIP Conference Proceedings",
      pages = "1411-1414",
      year = "2009",
      volume = "1168",
      number = "1" ,
     doi="10.1063/1.3241354"
}