Svetozar D. Margenov – författare

One of the current main challenges in the area of scientific computing​ is the design and implementation of accurate numerical models for complex physical systems which are described by time dependent coupled systems of nonlinear PDEs. This volume integrates the works of experts in computational mathematics and its applications, with a focus on modern algorithms which are at the heart of accurate modeling: adaptive finite element methods, conservative finite difference methods and finite volume methods, and multilevel solution techniques. Fundamental theoretical results are revisited in survey articles and new techniques in numerical analysis are introduced. Applications showcasing the efficiency, reliability and robustness of the algorithms in porous media, structural mechanics and electromagnetism are presented.   Researchers and graduate students in  numerical analysis and numerical solutions of PDEs and their scientific computing applications will find this book useful.

One of the current main challenges in the area of scientific computing​ is the design and implementation of accurate numerical models for complex physical systems which are described by time dependent coupled systems of nonlinear PDEs. This volume integrates the works of experts in computational mathematics and its applications, with a focus on modern algorithms which are at the heart of accurate modeling: adaptive finite element methods, conservative finite difference methods and finite volume methods, and multilevel solution techniques. Fundamental theoretical results are revisited in survey articles and new techniques in numerical analysis are introduced. Applications showcasing the efficiency, reliability and robustness of the algorithms in porous media, structural mechanics and electromagnetism are presented.   Researchers and graduate students in  numerical analysis and numerical solutions of PDEs and their scientific computing applications will find this book useful.

This book constitutes the thoroughly refereedpost-conference proceedings of the 10th International Conference on Large-ScaleScientific Computations, LSSC 2015, held in Sozopol, Bulgaria, in June 2015. The 49 revised full papers presented were carefullyreviewed and selected from 64 submissions.

This volume of the Springer Series "Lecture Notes in Computer Science" c- tains refereed papers which were presented at the Fifth International Conf- ence on Numerical Methods and Applications, NMA 2002, held in Borovets, Bulgaria, during 20-24 August 2002. The NMA 2002 Conference was organized by the Central Laboratory for Parallel Processing at the Bulgarian Academy of Sciences in cooperation with SIAM (Society for Industrial and Applied Mat- matics) and GAMM (Gesellschaft fur .. Angewandte Mathematik und Mechanik). Co-organizers of this traditional scienti?c meeting were the Institute of Mat- matics and Informatics at the Bulgarian Academy of Sciences and the Faculty of Mathematics and Informatics at the University of So?a. The conference was devoted to the 70th anniversary of the distinguished Bulgarian mathematician academician Blagovest Sendov - the founder of the Bulgarian school in - merical analysis, the teacher of dozens of Ph. D. students, the author of more than 270 papers, textbooks, and monographs. He is the scholar who has been at the center of the mathematical life in Bulgaria for about 50 years.Over the years he headed the Bulgarian Academy of Sciences, the University of So?a, the Faculty of Mathematics and Informatics of the University of So?a, the C- tral Laboratory for Parallel Processing of the Bulgarian Academy of Sciences, the Department of Mathematical Modeling of the Institute of Mathematics and Informatics, the Union of Bulgarian Mathematicians, etc. He represented with distinctionBulgarianscienceinsuchworld-recognizedorganizationsasIFIP (- ternationalFederationforInformationProcessing),theInternationalAssociation ofUniversities,theInternationalCouncilofScienti?cUnions,theBalkanMat- maticalUnion,etc.

Thepapersinthis volumewerepresentedatthe4thInternationalConferenceon Large-Scale Scienti?c Computations ICLSSC 2003. It was held in Sozopol, B- garia, June 4-8, 2003. The conference was organized and sponsored by the C- tral Laboratory for Parallel Processing at the Bulgarian Academy of Sciences. Support was also provided from the Center of Excellence "BIS 21" (funded by the European Commission), SIAM and GAMM. A co-organizer of this tra- tional scienti?c meeting was the Division of Numerical Analysis and Statistics of the University of Rousse. The success of the conference and the present volume in particular are the outcome of the joint e?orts of many colleagues from various institutions and organizations. First thanks to all the members of the Scienti?c Committee for their valuable contribution to forming the scienti?c face of the conference, as well as for their help in reviewing contributed papers. We would like to specially thank the organizers of the special sessions: R. Blaheta, N. Dimitrova, A. Ebel, K. Georgiev, O. Iliev, A. Karaivanova, H. Kosina, M. Krastanov, U. Langer, P. Minev, M. Neytcheva, M. Sch. afer, V. Veliov, and Z. Zlatev. We are also grateful to the sta? involved in the local organization.Special Events: - The conference was devoted to the 60th anniversary of Raytcho Lazarov. - During the conference, the nomination for the World Level of the Hall of Fame for Engineering, Science and Technology, HOFEST, was o?cially awarded to Owe Axelsson.

This book constitutes the thoroughly refereed post-proceedings of the 5th International Conference on Large-Scale Scientific Computations, LSSC 2005, held in Sozopol, Bulgaria in June 2005. The 75 revised full papers presented together with five invited papers were carefully reviewed and selected for inclusion in the book. The papers are organized in topical sections.

The papers in this volume were presented at ICLSSC 2001, the Third Inter- tionalConferenceonLarge-ScaleScienti?cComputing. ICLSSC2001washeldin Sozopol,Bulgaria,June6-10,2001. Theconferencewasorganizedandsponsored bytheCentralLaboratoryonParallelProcessingoftheBulgarianAcademyof Sciences,andtheDepartmentofNumericalAnalysisandStatisticsoftheUniv- sityofRouse,Bulgaria. SupportwasalsoreceivedfromtheCenterofExcellence "BIS21"(fundedbytheEuropeanCommission),SIAM(SocietyforIndustrial andAppliedMathematics)anditsActivityGrouponSupercomputing. Weare indebtedtoourcolleagueswhohelpedusintheorganizationofthisconference. Wethanktheorganizersofthespecialsessions:O. Axelsson,I. Dimov,A. Ebel, K. Georgiev, V. Getov, S. Heinrich, O. Iliev, A. Karaivanova, S. Margenov, P. Minev, M. Sch. afer, and Z. Zlatev. We also thank I. Lirkov for the help in puttingtogetherthisbook. Thepurposeoftheconferencewastobringtogetherscientistsworkingwith largecomputationalproblemsinindustry,andspecialistsinthe?eldofnume- calanalysis'methodsande?cientexploitationofmodernhigh-speedcomputers. Someclassesofmethodsappearagainandagaininthenumericaltreatmentof problemsfromdi?erent?eldsofscienceandengineering.Theaimofthisconf- encewastoselectsomeofthesenumericalmethodsandplanfurtherexperiments onseveraltypesofparallelcomputers. Thekeylecturesreviewedthemostimp- tantnumericalalgorithmsandscienti?capplicationsonparallelcomputers. The invited speakers included university and practical engineers from industry, as wellasappliedmathematicians,numericalanalysts,andcomputerexperts. The generalthemeforICLSSC2001wasLarge-ScaleScienti?cComputing,focusing on: - Robustpreconditioningalgorithms, - MonteCarlomethods, - Advancedprogrammingenvironmentsforscienti?ccomputing, - Large-scalecomputationsinairpollutionmodeling, - Large-scalecomputationsformechanicalengineeringproblems,and - Numericalmethodsforincompressible?ow. The workshop itself attracted about 80 participants from around the world. Authors from over 15 countries submitted 52 papers, of which 7 were invited, and 45 were contributed. The Fourth International Conference (ICLSSC 2003) willtakeplacein2003. SvetozarMargenov October 2001 JerzyWa' sniewski PlamenYalamov TableofContents I Invited Papers OptimizingTwo-LevelPreconditionings fortheConjugateGradientMethod...3 O. AxelssonandI.Kaporin OntheParallelizationoftheSparseGridApproachforDataMining...22 J. GarckeandM. Griebel JavaCommunicationsforLarge-ScaleParallelComputing...33 V. GetovandM. Philippsen ContinuousPathBrownianTrajectoriesforDi?usionMonteCarlo viaFirst-andLast-PassageDistributions...46 J. A. Given,M. Mascagni,andCh. -O. Hwang MultilevelMonteCarloMethods...58 S. Heinrich IterativeAggregation/DisaggregationMethods forComputingSomeCharacteristicsofMarkovChains...68 I. MarekandP. Mayer Time-IntegrationAlgorithmsfortheComputerTreatment oftheHorizontalAdvectioninAirPollutionModels...81 Z. Zlatev II Robust Preconditioning Algorithms MIC(0)PreconditioningofRotatedTrilinearFEMEllipticSystems...95 I. GeorgievandS. Margenov SobolevSpacePreconditioningforMixedNonlinear EllipticBoundaryValueProblems...104 J. Kar'atsonandI. Farag'o OnaSchurComplementApproachforSolvingTwo-Level FiniteElementSystems...113 M. NeytchevaandO. Axelsson VIII III Monte Carlo Methods On-LineStateEstimationofManeuveringObjects bySequentialMonteCarloAlgorithm...125 D. Angelova,E. Semerdjiev,Tz. Semerdjiev,andP. Konstantinova OntheDyadicDiaphonyoftheSobol'Sequences...133 E. I.Atanassov AnImprovedMonteCarloAlgorithmforElasticElectronBackscattering fromSurfaces...141 I. T. Dimov,E. I. Atanassov,andM. K. Durchova StatisticalAlgorithmsforSimulationofElectronQuantumKinetics inSemiconductors-PartI...149 T. V. GurovandP. A. Whitlock AQuasi-MonteCarloMethodforIntegration withImprovedConvergence...158 A. Karaivanova,I. Dimov,andS. Ivanovska SolvingSystemsofLinearAlgebraicEquations UsingQuasirandomNumbers...

The 6th International Conference on Large-Scale Scienti?c Computations (LSSC 2007) was held in Sozopol, Bulgaria, June 5-9, 2007. The conference was organized by the Institute for Parallel Processing at the Bulgarian Academy of Sciences in cooperation with SIAM (Society for Industrial and Applied Ma- ematics). Partial support was also provided from project BIS-21++ funded by the European Commission in FP6 INCO via grant 016639/2005. The conference was devoted to the 60th anniversary of Richard E. Ewing. ProfessorEwingwasawardedthemedaloftheBulgarianAcademyofSciencesfor hiscontributionstotheBulgarianmathematicalcommunityandtotheAcademy ofSciences.Hiscareerspanned33years,primarilyinacademia,butalsoincluded industry. Since 1992 he worked at Texas A&M University being Dean of Science and Vice President of Research, as well as director of the Institute for Scienti?c Computation (ISC), which he founded in 1992. Professor Ewing is internati- ally well known with his contributions in applied mathematics, mathematical modeling, and large-scale scienti?c computations. He inspired a generation of researchers with creative enthusiasm for doing science on scienti?c compu- tions.The preparatorywork on this volume was almost done when the sad news came to us: Richard E. Ewing passed away on December 5, 2007 of an apparent heart attack while driving home from the o?ce.

This book constitutes the thoroughly refereed post-conference proceedings of the 4th International Conference on Numerical Analysis and Its Applications, NAA 2008, held in Lozenetz, Bulgaria in June 2008. The 61 revised full papers presented together with 13 invited papers were carefully selected during two rounds of reviewing and improvement. The papers address all current aspects of numerical analysis and discuss a wide range of problems concerning recent achievements in physics, chemistry, engineering, and economics. A special focus is given to numerical approximation and computational geometry, numerical linear algebra and numerical solution of transcendental equations, numerical methods for differential equations, numerical modeling, and high performance scientific computing.

The 7th International Conference on Large-Scale Scienti?c Computations (LSSC 2009) was held in Sozopol, Bulgaria, June 4-8, 2009. The conference was organized and sponsored by the Institute for Parallel Processing at the B- garian Academy of Sciences. The conference was devoted to the 70th birthday anniversary of Professor Zahari Zlatev. The Bulgarian Academy of Sciences awarded him the Marin Drinov medal on ribbon for his outstanding results in environmental mat- matics and for his contributions to the Bulgarian mathematical society and the Academy of Sciences. The plenary invited speakers and lectures were: - P. Arbenz, "?Finite Element Analysis of Human Bone Structures" - Y. Efendiev, "Mixed Multiscale Finite Element Methods Using Limited Global Information" - U. Langer, "Fast Solvers for Non-Linear Time-Harmonic Problems" - T. Manteu?el, "First-Order System Least-Squares Approach to Resistive Magnetohydrodynamic Equations" - K. Sabelfeld, "Stochastic Simulation for Solving Random Boundary Value Problems and Some Applications" - F. Tro ..ltzsch,"OnFinite ElementErrorEstimatesforOptimalControlPr- lems with Elliptic PDEs" - Z.Zlatev, "On Some Stability Properties of the Richardson Extrapolation Applied Together with the ?-method" The success of the conference and the present volume in particular are an outcome of the joint e?orts of many partnersfrom various institutions and or- nizations. Firstwe wouldlike to thank allthe membersofthe Scienti?c Comm- tee for their valuable contribution forming the scienti?c face of the conference, as well as for their help in reviewing contributed papers. We especially thank the organizers of the special sessions.

This book constitutes the thoroughly refereed post-conference proceedings of the 8th International Conference on Large-Scale Scientific Computations, LSSC 2011, held in Sozopol, Bulgaria, in June 2011. The 74 revised full papers presented together with 3 plenary and invited papers were carefully reviewed and selected from numerous submissions. The papers are organized in topical sections on robust multigrid, multilevel and multiscale, deterministic and stochastic methods for modeling highly heterogeneous media, advanced methods for transport, control and uncertain systems, applications of metaheuristics to large-scale problems, environmental modelling, large scale computing on many-core architectures, multiscale industrial, enviromental and biomedical problems, efficient algorithms of computational geometry, high performance Monte Carlo simulations, voxel based computations and contributed papers.