Householder Symposium XIX: Eric de Sturler, Howard Elman, Daniel Szyld, and Misha Kilmer Eric de Sturler (Google Scholar Profile)
Professor, Department of Mathematics, Virginia TechProfessor, Computational Modeling and Data Analytics, Academy of Integrated Science, Virginia TechSelected
Professional Activities
Board of Directors of the Computing Research Association (CRA) Local Organizing Committee, Householder Symposium XX, 2017 International Scientific Committee, 13th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials, October 19 – 22, 2014, Taua Resort, SP, Brazil Affiate faculty of Center for Synergistic Environments for Experimental Computing Affiliate faculty of the Materials Computation Center at the University of Illinois at Urbana-Champaign Selected Previous Boards, Conferences Chaired, Organizing Committees, AffiliationsCo-Chair, Workshop Efficient Solution of Large Systems of Nonlinear PDEs in Science, Ecole Normale Superieure de Lyon (2013) General co-Chair 13th IEEE International Conference on Computational Science and Engineering (2010) Member Scientific Committee SIAM Conference on Applied Linear Algebra 2012 Editor SIAM Journal on Numerical Analysis (2003-2009) Editor Applied Numerical Mathematics (2005-2015) Chair and organization Workshop on Building Bridges between Computational Mathematics and Electronic Structure (2008) Affiliate faculty of the Institute for Genomic Biology at the University of Illinois at Urbana-Champaign Program Director of the SIAM Activity Group on Supercomputing (2003-2006) Co-Chair of the Third SIAM Conference on Computational Science & Engineering (2005) IASTED International Conference on Parallel and Distributed Computing and Networks (PDCN), 2004, 2005, 2006,2007
(EdS, after Coleridge's The Rime
of the Ancient Mariner)
Virginia Tech, view from across the New River Recent publications (send email if not yet available online)1. Xiaojia Zhang, Eric de Sturler, Glaucio H. Paulino, Stochastic Sampling for Structural Topology Optimization with Many Load Cases: Density and Ground Structure Approaches, CMAME, submitted, available from http://arxiv.org/pdf/1609.03099v1.pdf. 2. W.C. Tyson, K. Swirydowicz, J.M. Derlaga, C.J. Roy, E. de Sturler, Improved Functional-Based Error Estimation and Adaptation without Adjoints, AIAA-2016-3809, 46th AIAA Fluid Dynamics Conference, AIAA Aviation 2016, June 13 – 17, Washington, D.C. 3. Meghan O’Connell, Misha E. Kilmer, Eric de Sturler, Serkan Gugercin, Computing Reduced Order Models via Inner-Outer Krylov Recycling in Diffuse Optical Tomography, submitted, available from http://arxiv.org/pdf/1602.00138v1.pdf. 4. Arielle Grim-McNally, Eric de Sturler, and Serkan Gugercin, Preconditioning Parametrized Linear Systems, submitted, available from http://arxiv.org/pdf/1601.05883v1.pdf. 5.
Kapil Ahuja, Peter Benner, Eric de Sturler,
and Lihong Feng, Recycling BiCGSTAB with an Application to
Parametric Model Order Reduction, SIAM Journal on Scientific Computing
37(5), S429 - S466, 2015. 6. Amit Amritkar, Eric de Sturler, Katarzyna Swirydowicz, Danesh Tafti, and Kapil Ahuja, Recycling Krylov subspaces for CFD applications, Journal of Computational Physics 303, 222 – 237, 2015. 7. Eric de Sturler, Serkan Gugercin, Misha E. Kilmer, Saifon Chaturantabut, Christopher Beattie, and Meghan O'Connell, Nonlinear Parametric Inversion using Interpolatory Model Reduction, SIAM Journal on Scientific Computing 37(3), B495 – B517, 2015. (draft http://arxiv.org/abs/1311.0922). 8. Alexandru Cioaca, Adrian Sandu, and Eric de Sturler, Efficient Methods for Computing Observation Impact in 4D-Var Data Assimilation, Computational Geosciences 17(6), 975 - 990, 2013. DOI 10.1007/s10596-013-9370-2. 9. Alexandru Cioaca, Adrian Sandu, Eric de Sturler, and Emil Constantinescu, Efficient Computation of Observation Impact in 4D-Var Data Assimilation, IFIP Advances in Information and Communication Technology 377:250 – 264, 2012. DOI: 10.1007/978-3-642-32677-6_16. 10. Kapil Ahuja, Eric de Sturler, Serkan Gugercin, and Eun R. Chang, Recycling BiCG with an Application to Model Reduction © 2012 SIAM, SIAM Journal on Scientific Computing 34(4):1925 – 1949, 2012. Selected
Projects and Centers
(brief
descriptions will come soon) · HPC Environments; Computational Algorithms and Applications; and Aerial Surveillance, in collaboration with Terry Herdman, John Burns, Eugene Cliff, Jeff Borggaard, and many others. · AFOSR BRI: Co-Design of Hardware/Software for Predicting MAV Aerodynamics, in collaboration with Wuchun Feng, Danesh Tafti, Chris Roy, and Adrian Sandu, and (at NC State) Jack Edwards, Hong Luo, and Frank Mueller. · Center for Synergistic Environments for Experimental Computing · Collaborative Research: Innovative Integrative Strategies for Nonlinear Parametric Inversion, NSF DMS-12-17156, in collaboration with Misha Kilmer (Tufts), Serkan Gugercin, and Chris Beattie. · Collaborative Research: CMG: Quantum Monte Carlo Calculations of Deep Earth Materials, NSF EAR 05-30643 and NSF DMS 1025327, in collaboration with David Ceperley (UIUC), Ron Cohen (CIW), and Burkhard Militzer (UC Berkeley). · MRI-R2: Acquisition of a Heterogeneous Supercomputing Instrument for Transformative Interdisciplinary Research, NSF CNS 0960081. · Materials Computation Center, funded by NSF. Selected Past Projects(brief
descriptions will come soon)
Postdocs & Students,
Teaching and Short Courses
Regular Classes
University of Illinois at Urbana-Champaign (Computer
Science)
Virginia
Tech (Mathematics)
· Math & CS 5485 Numerical Analysis and Software – Iterative Methods for Large Sparse Linear Systems (lecture notes) · Math & CS 5486 Numerical Analysis and Software – Large-Scale Optimization and Nonlinear Systems of Equations (lecture notes) · Nonlinear Inverse Problems (lecture notes) Short Courses
Publications
Selected Journal and Proceedings/Book Publications (send
email if not available online)
1. Xiaojia Zhang, Eric de Sturler, Glaucio H. Paulino, Stochastic Sampling for Structural Topology Optimization with Many Load Cases: Density and Ground Structure Approaches, CMAME, submitted 2. Meghan O’Connell, Misha E. Kilmer, Eric de Sturler, Serkan Gugercin, Computing Reduced Order Models via Inner-Outer Krylov Recycling in Diffuse Optical Tomography, submitted, available from http://arxiv.org/pdf/1602.00138v1.pdf 3. Arielle Grim-McNally, Eric de Sturler, and Serkan Gugercin, Preconditioning Parametrized Linear Systems, submitted, available from http://arxiv.org/pdf/1601.05883v1.pdf 4. Kapil Ahuja, Peter Benner, Eric de Sturler, and Lihong Feng, Recycling BiCGSTAB with an Application to Parametric Model Order Reduction, SIAM Journal on Scientific Computing 37(5), S429 - S466, 2015. 5. Amit Amritkar, Eric de Sturler, Katarzyna Swirydowicz, Danesh Tafti, and Kapil Ahuja, Recycling Krylov subspaces for CFD applications, Journal of Computational Physics 303, 222 – 237, 2015. 6. Eric
de Sturler, Serkan Gugercin,
Misha E. Kilmer, Saifon Chaturantabut, Christopher Beattie, and Meghan O'Connell,
Nonlinear Parametric Inversion using Interpolatory Model Reduction, SIAM Journal on
Scientific Computing 37(3), B495 – B517, 2015. draft available from http://arxiv.org/abs/1311.0922. 7. Alexandru Cioaca, Adrian Sandu, and Eric de Sturler, Efficient Methods for Computing Observation Impact in 4D-Var Data Assimilation, Computational Geosciences 17(6), 975 – 990, 2013. DOI 10.1007/s10596-013-9370-2. 8. Alexandru Cioaca, Adrian Sandu, Eric de Sturler, and Emil Constantinescu, Efficient Computation of Observation Impact in 4D-Var Data Assimilation, IFIP Advances in Information and Communication Technology 377:250 – 264, 2012. DOI: 10.1007/978-3-642-32677-6_16. 9. Kapil Ahuja, Eric de Sturler, Serkan Gugercin, and Eun R. Chang, Recycling BiCG with an Application to Model Reduction © 2012 SIAM, SIAM Journal on Scientific Computing 34(4):1925 – 1949, 2012. DOI: 10.1137/100801500. 10. Eric de Sturler and Misha Kilmer, A Regularized Gauss-Newton Trust Region Approach to Imaging in Diffuse Optical Tomography © 2011 SIAM, SIAM Journal on Scientific Computing 33(5):3057 – 3086, 2011. 11. Kapil Ahuja, Bryan Clark, Eric de Sturler, David Ceperley, and Jeongnim Kim, Improved Scaling for Quantum Monte Carlo on Insulators © 2011 SIAM, SIAM Journal on Scientific Computing 33:1837 – 1859, 2011. 12. Luis A. Motta Mello, Eric de Sturler, Glaucio H. Paulino, and Emilio C. Nelli Silva, Recycling Krylov subspaces for efficient large-scale electrical impedance tomography, Computer Methods in Applied Mechanics and Engineering 199:3101 – 3110, 2010, doi: 10.1016/j.cma.2010.06.001. 13. Glaucio H. Paulino, Eric de Sturler, Shun Wang, and Chau Le, Continuum Topology Optimization with Preconditioned Krylov Subspace Recycling, Journal for Structural and Multidisciplinary Optimization, being revised. 14. Eric de Sturler, Glaucio H. Paulino, and Shun Wang, Multilevel Preconditioners for Simulations and Optimization on Dynamic Adaptive Meshes, Proceedings IV European Congress on Computational Mechanics, Palais des Congres, Paris, France, May 16-21, 2010 (electronic). 15. Shun Wang, Eric de Sturler, and Glaucio H. Paulino, Dynamic Adaptive Mesh Refinement for Topology Optimization, International Journal for Numerical Methods in Engineering, being revised, available at http://arxiv.org/abs/1009.4975. 16. Xin-Guang Zhu, Eric de Sturler, Rafael Alba, and Stephen P. Long, A Simple Model of the Calvin Cycle Has Only One Physiologically Feasible Steady State under the Same External Conditions, Nonlinear Analysis Series B: Real World Applications 10, pp. 1490 - 1499, 2009, DOI: http://dx.doi.org/10.1016/j.nonrwa.2008.01.021. 17. Wei Pan, John Fettig, Eric de Sturler, and Xin-Guang Zhu, Impacts of Different Metabolite Measurement Protocols on Estimating Parameters in Complex Photosynthetic Carbon Metabolism Models, Proceedings of the Fourth International Conference on Computational Systems Biology (ISB2010) Suzhou, China, September 9–11, 2010, pp.373–380. 18. Shun Wang and Eric de Sturler, Multilevel Sparse Approximate Inverse Preconditioners for Adaptive Mesh Refinement, Linear Algebra and its Applications, 2009, DOI: http://dx.doi.org/10.1016/j.laa.2009.02.021. 19. Kapil Ahuja, Eric de Sturler, Eun R. Chang, and S. Gugercin, Recycling BiCG, submitted to SIAM Journal on Scientific Computing. 20. Xin-Guang Zhu, Eric de Sturler, Rafael Alba, and Stephen P. Long, A Simple Model of the Calvin Cycle Has Only One Physiologically Feasible Steady State under the Same External Conditions, Nonlinear Analysis Series B: Real World Applications 10, pp. 1490 - 1499, 2009, DOI: http://dx.doi.org/10.1016/j.nonrwa.2008.01.021. 21. Shun Wang and Eric de Sturler, Multilevel Sparse Approximate Inverse Preconditioners for Adaptive Mesh Refinement, Linear Algebra and its Applications, 2009, DOI: http://dx.doi.org/10.1016/j.laa.2009.02.021. 22. Eric de Sturler, Glaucio H. Paulino, and Shun Wang, Topology Optimization with Adaptive Mesh Refinement, Proceedings of the 6th International Conference on Computation of Shell and Spatial Structures IASS-IACM 2008: "Spanning Nano to Mega", May 28-31, 2008, Cornell University, Ithaca, NY, John F. Abels and J. Robert Cooke (eds), 23. Luis A.M. Mello, Emilio C.N. Silva, Eric de Sturler, and Glaucio H. Paulino, Topology Optimization Method Utilizing Iterative Solvers with Subspace Recycling Applied to High Resolution Electrical Impedance Tomography, Proceedings of the 6th International Conference on Computation of Shell and Spatial Structures IASS-IACM 2008: "Spanning Nano to Mega", May 28-31, 2008, Cornell University, Ithaca, NY, John F. Abels and J. Robert Cooke (eds), 24. Eric de Sturler, Chau Le, Shun Wang, and Glaucio Paulino, Large Scale Topology Optimization Using Preconditioned Krylov Subspace Recycling and Continuous Approximation of Material Distribution, Multiscale and Functionally Graded Materials 2006 (M&FGM 2006), Oahu Island (Hawaii), 15–18 October 2006, AIP Conference Proceedings Volume 973, pp. 279 - 284, 2008, ISBN: 978-0-7354-0492-2, Editor(s): G. H. Paulino, M.-J. Pindera, R. H. Dodds, Jr., F. A. Rochinha, E. Dave, and L. Chen, 25. Xin-Guang Zhu, Eric de Sturler, Stephen Long, Optimizing the distribution of resources between enzymes of carbon metabolism can dramatically increase photosynthetic rate. A numerical simulation using an evolutionary algorithm, Plant Physiology, October 2007, Vol. 145, pp. 513—526, 2007; DOI:10.1104/pp.107.103713, www.plantphysiol.org (open access article) 26. Shun Wang, Eric de Sturler, and Glaucio H. Paulino, Large-Scale Topology Optimization using Preconditioned Krylov Subspace Methods with Recycling, International Journal for Numerical Methods in Engineering, Vol. 69, Issue 12, pp. 2441—2468, 2007, DOI: 10.1002/nme.1798, original version available as Technical Report UIUCDCS-R-2006-2678 and UILU-ENG-2006-1705. 27. Mike Parks, Eric de Sturler, Greg Mackey, Duane D. Johnson, and Spandan Maiti, Recycling Krylov Subspaces for Sequences of Linear Systems ©2006 SIAM, SIAM Journal on Scientific Computing, Vol. 28, No. 5, pp. 1651-1674, 2006, original version available as tech. report UIUCDCS-R-2004-242, March 2004, 28. Chris Siefert and Eric de Sturler, Probing Methods for Saddle-Point Problems, Electronic Transactions in Numerical Analysis (ETNA), Volume 22, pp. 163-183, 2006, in Special Volume on "Saddle Point Problems: Numerical Solution and Applications", original version available as Tech. Report UIUCDCS-R-2005-2540 and UILU-ENG-2005-1744, March 2005, 29. Chris Siefert and Eric de Sturler, Preconditioners for Generalized Saddle-Point Problems ©2006 SIAM, SIAM Journal on Numerical Analysis, 44(3), pp. 1275-1296, 2006, original version available as Technical Report UIUCDCS-R-2004-2448 and UILU-ENG-2004-1750, June 2004. 30. Saddle Point Problems: Numerical Solution and Applications, Special Volume of Electronic Transactions on Numerical Analysis (ETNA), Volume 22, 2006, Michele Benzi, Richard B. Lehoucq, and Eric de Sturler (editors), 31. Misha Kilmer and Eric de Sturler, Recycling Subspace Information for Diffuse Optical Tomography ©2006 SIAM, SIAM Journal on Scientific Computing 27(6), pp. 2140-2166, 2006, original version available as Technical Report UIUCDCS-R-2004-2447, June 2004, 32. Chris Siefert and Eric de Sturler, Preconditioners for Generalized Saddle-Point Problems, accepted for publication in SIAM Journal on Numerical Analysis, December 2005, original version available as Technical Report UIUCDCS-R-2004-2448, June 2004, 33. Xin-Guang Zhu, Govindjee, Neil Baker, Eric de Sturler, Donald R. Ort, Stephen P. Long, Chlorophyll a fluorescence induction kinetics in leaves predicted from a model describing each discrete step of excitation energy and electron transfer associated with Photosystem II, Planta 223(1), pages 114-133, 2005; the original publication is available at www.springerlink.com as pdf or html, 34. Eric de Sturler and Jörg Liesen, Block-diagonal and Constraint Preconditioners for Nonsymmetric Indefinite Linear Systems. Part I: Theory ©2005 SIAM, SIAM Journal on Scientific Computing 26(5), pp. 1598-1619, 2005, 35. Eric de Sturler, Improving the Convergence of the Jacobi-Davidson Algorithm, Technical Report UIUCDCS-R-2000-2173, 2000, 36. A. Sheffer and E. de Sturler, Smoothing an Overlay Grid to Minimize Linear Distortion in Texture Mapping ©2002 ACM, ACM Transaction on Graphics 21(4), pp. 874-890, 2002 (final draft with color graphics). 37. A. Sheffer and E. de Sturler, Parameterization of Faceted Surfaces for Meshing Using Angle Based Flattening (final draft), Engineering with Computers 17(3) (2001), pp. 326-337. (available from Springer) Special issue containing 10 selected (and updated) papers from the 9th International Meshing Round Table Conference 2000. 38. J. Liesen, E. de Sturler, A. Sheffer, Y. Aydin, C. Siefert, Preconditioners for Indefinite Linear Systems Arising in Surface Parameterization, Proceedings of the 10th International Meshing Round Table, Newport Beach, CA, October 7-10, 2001, Sandia National Laboratories, (also available from http://www.andrew.cmu.edu/user/sowen/imr10.html), 39. E. de Sturler, J. Hoeflinger, L. Kale, and M. Bhandarkar, A New Approach to Software Integration Frameworks for Multi-Physics Simulation codes, in The Architecture of Scientific Software, R.F. Boisvert, P.T.P. Tang, eds., Kluwer Academic Publishers, Boston, 2001, ISBN 0-7923-7339-1. 40. M. Bhandarkar, L.V. Kale, E. de Sturler, J. Hoeflinger, Adaptive Load Balancing for MPI Programs, Lecture Notes in Computer Science 2074, V.N. Alexandrov e.a. (Eds.): Proceedings of the International Conference in Computational Science, May 28-30, 2001, San Francisco, CA, pp. 108-117, Springer-Verlag, 2001. 41. A. Sheffer and E. de Sturler, Surface Parameterization for Meshing by Triangulation Flattening, Proceedings of the 9th International Meshing Round Table Conference 2000, New Orleans, October 2-5, 2000, pp. 161-172, Sandia National Laboratories, (also available from http://www.andrew.cmu.edu/user/sowen/imr9.html). 42. A. Sheffer and E. de Sturler, Parameterization of CAD surfaces for Meshing by Triangulation Flattening, Proceedings of the 7th International Conference on Numerical Grid Generation in Computational Field Simulations, pp. 699-708, September 25-28, 2000 in Whistler, British Columbia, Canada. 43. E. de Sturler, Truncation Strategies for Optimal Krylov Subspace Methods, ©1999 SIAM, SIAM Journal on Numerical Analysis Vol. 36 (1999), pp. 864-889. Awarded the second prize at the Leslie Fox Prize Meeting 1997. 44. E. de Sturler. Variations on the Jacobi-Davidson Theme. In David Kincaid and Anne Elster, editors: Iterative Methods in Scientific Computation IV: Proceedings of the Fourth IMACS International Symposium on Iterative Methods in Scientific Computation, honoring the 75th birthday of David M. Young, Austin, Texas, October 18-20, 1998, IMACS series in Computational and Applied Mathematics, Volume 5, IMACS 1999, pp. 313-323. 45. E. de Sturler. BiCG Explained. Householder Symposum XIV: Proceedings of the Householder International Symposium in Numerical Algebra, Chateau Whistler, Whistler, BC, Canada, June 13-19, 1999. 46. E. de Sturler and D. Loher, Parallel Iterative Solvers for Irregular Sparse Matrices in High Performance Fortran, Journal of Future Generation Computer Systems Vol. 13 (1998), pp. 315-325. Special issue containing updated versions of the 15 best papers selected out of 130 papers accepted for HPCN’97. 47. E. de Sturler and V. Strumpen, Scientific Programming with High Performance Fortran: A Case Study Using the xHPF Compiler, Scientific Programming Vol. 6 (1997), pp. 127-152. Special issue: High Performance Fortran Comes of Age. 48. E. de Sturler and D. Loher. Implementing Iterative Solvers for Irregular Sparse Matrix Problems in High Performance Fortran. In C.D. Polychronopoulos, K. Joe, K. Araki, M. Amamiya, editors: High Performance Computing, International Symposium, ISHPC'97, Fukuoka, Japan, November 4 - 6, 1997, Lecture Notes in Computer Science 1336, Springer-Verlag, Berlin, Heidelberg, Germany, 1997. 49. E. de Sturler, Nested Krylov Methods based on GCR, Journal of Computational and Applied Mathematics Vol. 67 (1996), pp. 15-41. 50. E. de Sturler, A Performance Model for Krylov Subspace Methods on Mesh-based Parallel Computers, Parallel Computing Vol. 22 (1996), pp. 57-74. 51. E. de Sturler. Inner-outer Methods with Deflation for Linear Systems with Multiple Right-Hand Sides. In Householder Symposium XIII, Proceedings of the Householder Symposium on Numerical Algebra, pp. 193-196. June 17 - 26, 1996, Pontresina, Switzerland. 52. E. de Sturler and H. A. van der Vorst, Reducing the Effect of Global Communication in GMRES(m) and CG on Parallel Distributed Memory Computers, Applied Numerical Mathematics (IMACS), Vol. 18 (1995), pp. 441-459. 53. F. Nataf, F. Rogier, and E. de Sturler. Domain Decomposition Methods for Fluid Dynamics. In A. Sequeira, editor: Navier-Stokes Equations and Related Nonlinear Problems, pp. 367-376, New York, 1995. Plenum Press. 54. E. de Sturler, Incomplete Block LU Preconditioners on Slightly Overlapping Subdomains for a Massively Parallel Computer, Applied Numerical Mathematics (IMACS), Vol. 19 (1995), pp. 129-146. 55. Eric de Sturler. IBLU Preconditioners for Massively Parallel Computers. In D. E. Keyes & J. Xu, editors: Domain Decomposition Methods in Science and Engineering, Proceedings of the Seventh International Conference on Domain Decomposition, October 27-30, 1993, The Pennsylvania State University, pp. 395-400, American Mathematical Society, Providence, USA, 1994. 56. C. Clémençon, K. M. Decker, A. Endo, J. Fritscher, G. Jost, T. Maruyama, N. Masuda, A. Müller, R. Rühl, W. Sawyer, E. de Sturler, B. J. N. Wylie, and F. Zimmermann, Architecture and Programmability of the NEC Cenju-3, SPEEDUP, Vol. 8(2) (1994), pp. 15-22. 57. E. de Sturler. Iterative Methods on Distributed Memory Computers, Ph.D. thesis, Delft University of Technology, Delft, The Netherlands, October 1994 (ISBN 90-9007579-8). 58. E. de Sturler and H. A. van der Vorst. Communication Cost Reduction for Krylov Methods on Parallel Computers. In W. Gentzsch and U. Harms, editors: High-Performance Computing and Networking, Lecture Notes in Computer Science 797, pages 190-195, Springer-Verlag, Berlin, Heidelberg, Germany, 1994. 59. E. de Sturler and D. R. Fokkema. Nested Krylov Methods and Preserving the Orthogonality. In N. Duane Melson, T. A. Manteuffel, and S. F. McCormick, editors, Sixth Copper Mountain Conference on Multigrid Methods, NASA Conference Publication 3224, Part 1, pages 111-125, NASA Langley Research Center, Hampton, VA, USA, 1993. 60. E. de Sturler. A Parallel Variant of GMRES(m). In J.J.H. Miller and R.Vichnevetsky, editors, Proceedings of the 13th IMACS World Congress on Computation and Applied Mathematics, pp. 682-683, Dublin, Ireland, 1991. Criterion Press. 61. G. H. Schmidt and E. de Sturler. Multigrid for porous medium flow on locally refined three dimensional grids. In W. Hackbusch and U. Trottenberg, editors, Multigrid Methods: Special Topics and Applications II, proceedings of the 3rd European Conference on Multigrid Methods, Bonn, Germany, October 1-4, 1990, GMD-Studien Nr. 189, pages 309-318, Gesellschaft für Mathematik und Datenverarbeitung, Sankt Augustin, Germany, 1991. |