Institute for Mathematics and its Applications University of Minnesota 114 Lind Hall 207 Church Street SE Minneapolis, MN 55455 
20082009 Program
See http://www.ima.umn.edu/20082009 for a full description of the 20082009 program on Mathematics and Chemistry.
2005 New Directions Short Course instructor Alexei Kitaev of Caltech named MacArthur fellow
The halfmilliondollar award, often referred to as the "genius award," is an unrestricted fellowships given to talented individuals who have shown extraordinary originality and dedication in their creative pursuits and a marked capacity for selfdirection.
8:00am8:45am  Breakfast and registration  EE/CS 3176  SW11.1.08  
8:45am9:00am  Welcome (Fadil Santosa and NSF officer)  Fadil Santosa (University of Minnesota)  EE/CS 3180  SW11.1.08 
9:00am9:30am  Challenges in efficient and inexpensive solartoelectric energy conversion  Eray S. Aydil (University of Minnesota)  EE/CS 3180  SW11.1.08 
9:30am10:30am  Multiple exciton generation in semiconductor quantum dots and novel molecules: Applications to third generation solar photon conversion  Arthur J. Nozik (Department of Energy)  EE/CS 3180  SW11.1.08 
10:30am11:00am  Break and discussion  EE/CS 3176  SW11.1.08  
11:00am12:00pm  Quantum dots and dyesensitized semiconductors for solar energy conversion: timedomain ab initio studies of the photoinduced dynamics  Oleg Prezhdo (University of Washington)  EE/CS 3180  SW11.1.08 
12:00pm12:30pm  Engineering morphology in small molecule organic photovoltaic cells for efficient exciton diffusion and dissociation  Russell J. Holmes (University of Minnesota)  EE/CS 3180  SW11.1.08 
12:30pm1:30pm  Lunch and discussion  EE/CS 3180  SW11.1.08  
1:30pm2:30pm  Exciton dissociation in solar cells  Xiaoyang Zhu (University of Minnesota)  EE/CS 3180  SW11.1.08 
2:30pm3:00pm  Functionalized quantum dots and conjugated polymers for light harvesting applications: Theoretical insights  Sergei Tretiak (Los Alamos National Laboratory)  EE/CS 3180  SW11.1.08 
3:00pm3:30pm  Break and discussion  EE/CS 3176  SW11.1.08  
3:30pm4:00pm  Computational aspects of solid state transport  Christian Ringhofer (Arizona State University)  EE/CS 3180  SW11.1.08 
4:00pm4:30pm  Receiver technology for today and tomorrow  Alex Marker (Schott North America, Inc.)  EE/CS 3180  SW11.1.08 
4:30pm5:00pm  Environmentassisted quantum transport in photosynthetic complexes: Learning from nature for potential organic photovoltaic applications.  Alán AspuruGuzik (Harvard University)  EE/CS 3180  SW11.1.08 
5:00pm5:30pm  CHEDMRDMS solar energy initiative  Henry A. Warchall (National Science Foundation)  EE/CS 3180  SW11.1.08 
8:15am8:45am  Coffee and registration  EE/CS 3176  T11.2.08  
8:45am9:00am  Welcome  Fadil Santosa (University of Minnesota)  EE/CS 3180  T11.2.08 
9:00am10:30am  A mathematical perspective on the structure of matter  Richard D. James (University of Minnesota)  EE/CS 3180  T11.2.08 
10:30am10:45am  Group photo  
10:30am11:00am  Break  EE/CS 3176  T11.2.08  
10:45am11:15am  Break  EE/CS 3176  
11:00am12:30pm  Basic concepts of polymer physics and their numerical study  Burkhard Dünweg (MaxPlanck Institut für Polymerforschung)  EE/CS 3180  T11.2.08 
12:30pm2:00pm  Lunch  T11.2.08  
2:00pm3:30pm  Capturing the macroscopic behavior of complex systems using multiscale methods  Weinan E (Princeton University)  EE/CS 3180  T11.2.08 
3:30pm4:00pm  Discussion  EE/CS 3180  T11.2.08 
8:15am8:45am  Coffee and registration  EE/CS 3176  T11.2.08  
8:45am9:00am  Welcome  Fadil Santosa (University of Minnesota)  EE/CS 3180  T11.2.08 
9:00am10:30am  A mathematical perspective on the structure of matter  Richard D. James (University of Minnesota)  EE/CS 3180  T11.2.08 
10:30am10:45am  Group photo  
10:30am11:00am  Break  EE/CS 3176  T11.2.08  
10:45am11:15am  Break  EE/CS 3176  
11:00am12:30pm  Basic concepts of polymer physics and their numerical study  Burkhard Dünweg (MaxPlanck Institut für Polymerforschung)  EE/CS 3180  T11.2.08 
12:30pm2:00pm  Lunch  T11.2.08  
2:00pm3:30pm  Capturing the macroscopic behavior of complex systems using multiscale methods  Weinan E (Princeton University)  EE/CS 3180  T11.2.08 
3:30pm4:00pm  Discussion  EE/CS 3180  T11.2.08 
All Day  Multiscale modeling in soft and biological matter, I
Session Chair: Frank L. H. Brown (University of California)  W11.37.08  
8:15am9:00am  Registration and coffee  EE/CS 3176  W11.37.08  
9:00am9:15am  Welcome to the IMA  Fadil Santosa (University of Minnesota)  EE/CS 3180  W11.37.08 
9:15am10:00am  Multiscale structural mechanics of viruses: Stretching the limits of continuum modeling  William S. Klug (University of California, Los Angeles)  EE/CS 3180  W11.37.08 
10:00am10:30am  Coffee  EE/CS 3176  W11.37.08  
10:30am11:15am  Coarsegraining of cholesterol containing lipid bilayers  Mikko Karttunen (University of Western Ontario)  EE/CS 3180  W11.37.08 
11:15am12:00pm  Coarsegrained simulation studies of mesoscopic membrane phenomena  Markus Deserno (Carnegie Mellon University)  EE/CS 3180  W11.37.08 
12:00pm2:00pm  Lunch  W11.37.08  
2:00pm2:45pm  Soft coarsegrained models for multicomponent polymer melts: free energy and singlechain dynamics  Marcus Müller (GeorgAugustUniversität zu Göttingen)  EE/CS 3180  W11.37.08 
2:45pm3:30pm  Simple models for biomembrane structure and dynamics  Frank L. H. Brown (University of California, Santa Barbara)  EE/CS 3180  W11.37.08 
3:30pm3:45pm  Group Photo  W11.37.08  
3:45pm4:15pm  Coffee  EE/CS 3176  W11.37.08  
4:15pm4:45pm  Second chances  EE/CS 3180  W11.37.08  
5:00pm6:30pm  Reception and Poster Session
Poster submissions welcome from all participants  Lind Hall 400  W11.37.08  
Ligand access/escape from protein cavities: A computational study of the insulinphenol complex  Cameron F. Abrams (Drexel University)  
Charge transport in discotic liquid crystals: a multiscale computer simulation study  Denis Andrienko (MaxPlanck Institut für Polymerforschung)  
Parallel multiscale simulation for crack propagation  Olivier Coulaud (Institut National de Recherche en Informatique Automatique (INRIA))  
A criterion to estimate the quality of the Mapping Scheme in Coarsegraining approaches  Luigi Delle Site (MaxPlanck Institut für Polymerforschung)  
Realistic multiscale modeling of spatiotemporal behavior in surface reactions: Equationfree "heterogeneous coupled latticegas" (HCLG) simulations  James W. Evans (Iowa State University)  
Multiscale modeling of polystyrene in different environments  Roland Faller (University of California, Davis)  
Multiscale modeling of structure and phase behavior in heterogeneous lipid bilayers  Roland Faller (University of California, Davis)  
From atomistic to mesoscale systems without fitting: A coarse grained model for polystyrene  Dominik Fritz (Max Planck Institute for Polymer Research)  
From quantum to classical molecular dynamics  Johannes Giannoulis (Technical University of Munich )  
Comparative study of water: Atomistic vs. coarsegrained  Christoph Junghans (MaxPlanck Institut für Polymerforschung)  
Techniques for coarsegrained modeling and mechanics of viral capsids  William S. Klug (University of California, Los Angeles)  
Effective dynamics using conditional expectations  Frédéric Legoll (École Nationale des PontsetChaussées)  
Force matching versus structural coarsegraining  Alexander Lukyanov (MaxPlanck Institut für Polymerforschung)  
A new procedure to building stabilized explicit RungeKutta methods for large systems of ODEs  Jesús MartínVaquero (University of Salamanca)  
Quantifying chain reptation in entangled polymers by mapping atomistic simulation results onto the tube model  Vlasis George Mavrantzas (University of Patras)  
Allatom multiscale computational modeling of bionanosystem dynamics  Stephen D Pankavich (Indiana University)  
Adaptive resolution simulation of model mixtures  Simon Poblete (Max Planck Institute for Polymer Research)  
Charge transport in polypyrrole: the role of morphology  Victor Rühle (Max Planck Institute for Polymer Research)  
Spatial bounds on the effective complex permittivity for timeharmonic waves in random media  Lyubima B. Simeonova (University of Utah)  
General purpose molecular dynamics on graphic processing units (GPUs)  Alex Travesset (Iowa State University)  
Mesoscopic model for the fluctuating hydrodynamics of binary and ternary mixtures  Erkan Tüzel (University of Minnesota)  
A bloch band base level set method in the semiclassical limit of the Schroedinger Equation  Zhongming Wang (University of California, San Diego) 
All Day  Molecular dynamics Session Chair: Anne M. Chaka (National Institute of Standards and Technology)  W11.37.08  
8:30am9:15am  Coffee  EE/CS 3176  W11.37.08  
9:15am10:00am  Coarsegrained and multiscale models of bulk liquids and macromolecules  Teresa HeadGordon (University of California, Berkeley)  EE/CS 3180  W11.37.08 
10:00am10:30am  Coffee  EE/CS 3176  W11.37.08  
10:30am11:15am  Understanding effective molecular dynamics on timescales beyond possible simulation timescales  Christof Schütte (Freie Universität Berlin)  EE/CS 3180  W11.37.08 
11:15am12:00pm  Lattice Boltzmann simulations of softmatter systems  Burkhard Dünweg (MaxPlanck Institut für Polymerforschung)  EE/CS 3180  W11.37.08 
12:00pm2:00pm  Lunch  W11.37.08  
2:00pm2:45pm  Multiscale modeling and simulation of soft matter materials  Paul J. Atzberger (University of California, Santa Barbara)  EE/CS 3180  W11.37.08 
2:45pm3:30pm  Soft potentials for coarse grained modeling  Ignacio Pagonabarraga Mora (University of Barcelona)  EE/CS 3180  W11.37.08 
3:30pm4:00pm  Coffee  EE/CS 3176  W11.37.08  
4:00pm4:30pm  Second chances  EE/CS 3180  W11.37.08 
All Day  Mathematical aspects of scalebridging Session Chair: Gero Friesecke (Technische Universität München)  W11.37.08  
8:30am9:15am  Coffee  EE/CS 3176  W11.37.08  
9:15am10:00am  Some representative issues in multiscale modeling  Weinan E (Princeton University)  EE/CS 3180  W11.37.08 
10:00am10:30am  Coffee  EE/CS 3176  W11.37.08  
10:30am11:15am  A general strategy for the design of seamless multiscale methods  Eric VandenEijnden (New York University)  EE/CS 3180  W11.37.08 
11:15am12:00pm  Predictive and efficient quasicontinuum methods  Mitchell Luskin (University of Minnesota)  EE/CS 3180  W11.37.08 
12:00pm2:00pm  IMA Special Lunch  W11.37.08  
2:00pm2:45pm  Variational coarsegraining of lattice systems  Andrea Braides (Seconda Università di Roma "Tor Vergata")  EE/CS 3180  W11.37.08 
2:45pm3:30pm  Positive temperature coarsegraining of onedimensional systems  Claude Le Bris (CERMICS)  EE/CS 3180  W11.37.08 
3:30pm4:00pm  Coffee  EE/CS 3176  W11.37.08  
4:00pm4:30pm  Second chances  EE/CS 3180  W11.37.08 
All Day  Multiscale modeling in soft and biological matter, II Session Chair: Kurt Kremer (MaxPlanck Institut für Polymerforschung)  W11.37.08  
8:15am8:45am  Coffee  EE/CS 3176  W11.37.08  
8:45am9:30am  A rigorous multiscale bridge connecting atomistic and coarsegrained models  William G. Noid (Pennsylvania State University)  EE/CS 3180  W11.37.08 
9:30am9:45am  Grab a cup of coffee then proceed immediately to 331 Smith Hall for the 9:45am Moscowitz Lecture  EE/CS 3176  W11.37.08  
9:45am10:45am  Michael Frisch
Moscowitz Lecture (Chemistry Department) author of the widely used Gaussian computer program (for electronic structure calculations (including some multiscale algorithms) and the President of Gaussian, Inc.]  331 Smith Hall  W11.37.08  
11:00am11:45am  Molecular dynamics in mesoscopic solvents  Raymond Kapral (University of Toronto)  EE/CS 3180  W11.37.08 
11:15am12:15pm  Francisco Sayas Gonzalez,
University of Zaragoza, Spain TBA  Vincent Hall 570  AMS  
11:45am12:30pm  Unveiling conformational changes of biological molecules using multiscale modeling and multiresolution experiments  Florence Tama (University of Arizona)  EE/CS 3180  W11.37.08 
12:30pm2:00pm  Lunch  W11.37.08  
2:00pm2:45pm  Multiscale modeling of DNA  Wilma K. Olson (Rutgers University)  EE/CS 3180  W11.37.08 
2:45pm3:30pm  Mapping particle based simulations to mesoscopic models  Mark O. Robbins (Johns Hopkins University)  EE/CS 3180  W11.37.08 
3:30pm4:00pm  Coffee  EE/CS 3176  W11.37.08  
4:00pm4:45pm  Development of dynamic density functional theories of multiphase dense polymeric systems  Toshihiro Kawakatsu (Tohoku University)  EE/CS 3180  W11.37.08 
4:45pm5:15pm  Second chances  EE/CS 3180  W11.37.08  
7:00pm8:30pm  Workshop Dinner  Pagoda Restaurant 1417 4th St. SE Minneapolis, MN 6123784710 
W11.37.08 
All Day  Algorithmic aspects of scalebridging Session Chair: Yousef Saad (University of Minnesota)  W11.37.08  
8:30am9:15am  Coffee  EE/CS 3176  W11.37.08  
9:15am10:00am  The adaptive resolution simulation scheme (AdResS): Basic principles and applications  Luigi Delle Site (MaxPlanck Institut für Polymerforschung)  EE/CS 3180  W11.37.08 
10:00am10:30am  Coffee  EE/CS 3176  W11.37.08  
10:30am11:15am  Atomistic, mesoscopic and continuum hydrodynamics: coupling liquid models with different resolution  Rafael DelgadoBuscalioni (Autonomous University of Madrid)  EE/CS 3180  W11.37.08 
11:15am12:00pm  Finding effective equations for heterogeneous multiscale methods  Bjorn Engquist (University of Texas)  EE/CS 3180  W11.37.08 
12:00pm12:30pm  Second chances and closing remark  EE/CS 3180  W11.37.08 
10:45am11:15am  Coffee break  Lind Hall 400  
2:30pm3:30pm  Math 8994: Topics in classical and
quantum mechanics Electronic structure calculations and molecular simulation: A mathematical initiation  Eric Cances (CERMICS) Claude Le Bris (CERMICS)  Lind Hall 305 
10:45am11:15am  Coffee break  Lind Hall 400  
11:15am12:15pm  A theory of fracture based upon extension of continuum mechanics to the nanoscale  Tsvetanka Sendova (University of Minnesota)  Lind Hall 305  PS 
12:15pm1:30pm  postdoc lunch meeting  Lind Hall 409 
10:45am11:15am  Coffee break  Lind Hall 400  
2:30pm3:30pm  Math 8994: Topics in classical and
quantum mechanics Electronic structure calculations and molecular simulation: A mathematical initiation  Eric Cances (CERMICS) Claude Le Bris (CERMICS)  Lind Hall 305  
4:00pm5:00pm  Fermi contact interactions evaluated from hidden relations in the Schrödinger equation  Daniel M. Chipman (University of Notre Dame)  Lind Hall 305  SMC 
10:45am11:15am  Coffee break  Lind Hall 400  
11:15am12:15pm  TBA  Eric Cances (CERMICS)  Vincent Hall 570  AMS 
4:00pm5:00pm  Reading group for Professor Ridgway Scott's book "Digital Biology"  Ridgway Scott (University of Chicago)  Lind Hall 401 
10:45am11:15am  Coffee break  Lind Hall 400  
1:25pm2:25pm  Image registration with applications in medical imaging towards drug discovery and development  Belma Dogdas (Merck & Co., Inc.)  Vincent Hall 570  IPS 
8:00am8:45am  Registration and coffee  EE/CS 3176  SW11.1721.08  
8:45am9:00am  Welcome to the IMA  Fadil Santosa (University of Minnesota)  EE/CS 3180  SW11.1721.08 
9:00am10:00am  Building an effective solver for convex mixed integer nonlinear programs  Jeff Linderoth (University of Wisconsin)  EE/CS 3180  SW11.1721.08 
10:00am10:30am  Coffee  EE/CS 3176  SW11.1721.08  
10:30am11:15am  Branching strategies and heurisitcs in a branchandbound for convex MINLPs  Pierre Bonami (Centre National de la Recherche Scientifique (CNRS))  EE/CS 3180  SW11.1721.08 
11:15am12:00pm  Branching rules in branchandbound algorithms for nonconvex mixedinteger nonlinear programming  Pietro Belotti (Lehigh University)  EE/CS 3180  SW11.1721.08 
12:00pm2:00pm  Lunch  SW11.1721.08  
2:00pm2:45pm  Fast infeasibility detection in nonlinear optimization  Jorge Nocedal (Northwestern University)  EE/CS 3180  SW11.1721.08 
2:30pm3:30pm  Math 8994: Topics in classical and
quantum mechanics Electronic structure calculations and molecular simulation: A mathematical initiation  Eric Cances (CERMICS) Claude Le Bris (CERMICS)  Lind Hall 305  
2:45pm3:30pm  Using interiorpoint methods within MINLP  Hande Yurttan Benson (Drexel University)  EE/CS 3180  SW11.1721.08 
3:30pm3:45pm  Group Photo  SW11.1721.08  
3:45pm4:15pm  Coffee  EE/CS 3176  SW11.1721.08  
4:15pm5:15pm  Discussion  Sven Leyffer (Argonne National Laboratory)  EE/CS 3180  SW11.1721.08 
8:30am9:00am  Coffee  EE/CS 3176  SW11.1721.08  
9:00am10:00am  Copositive programs and combinatorial optimization  Franz Rendl (Universität Klagenfurt)  EE/CS 3180  SW11.1721.08 
10:00am10:30am  Coffee  EE/CS 3176  SW11.1721.08  
10:30am11:15am  The difference between 5x5 doubly nonnegative and completely positive matrices  Kurt M. Anstreicher (University of Iowa)  EE/CS 3180  SW11.1721.08 
11:15am12:00pm  Convex relaxations of nonconvex MIQCP  Anureet Saxena (Axioma Inc.)  EE/CS 3180  SW11.1721.08 
12:00pm2:00pm  Lunch  SW11.1721.08  
2:00pm2:45pm  A branchandrefine method for nonconvex mixed integer optimization  Annick Sartenaer (Facultés Universitaires Notre Dame de la Paix (Namur))  EE/CS 3180  SW11.1721.08 
2:45pm3:30pm  Reformulations in mathematical programming: Symmetry  Leo Liberti (École Polytechnique)  EE/CS 3180  SW11.1721.08 
3:30pm4:00pm  Coffee  EE/CS 3176  SW11.1721.08  
4:00pm5:00pm  Discussion  Francois Margot (Carnegie Mellon University)  EE/CS 3180  SW11.1721.08 
5:00pm6:30pm  Poster Session and Reception: 5:006:30 Poster submissions welcome from all participants  Lind Hall 400  SW11.1721.08  
Water network design by MINLP  Claudia D'Ambrosio (Università di Bologna)  
HIPO: A nonlinear mixed integer constrained optimization algorithm for treatment planning in brachytherapy  Andreas G. Karabis (PI Medical Ltd)  
Variable neighbourhood search for MINLPs  Giacomo Nannicini (École Polytechnique)  
Direct numerical methods for mixedinteger optimal control problems  Sebastian Sager (RuprechtKarlsUniversität Heidelberg)  
Convex relaxations of nonconvex MIQCP  Anureet Saxena (Axioma Inc.)  
Some challenging mixed integer nonlinear optimization problems  Tamás Terlaky (Lehigh University)  
Exact algorithms for the quadratic linear ordering problem  Angelika Wiegele (Universität Klagenfurt) 
8:30am9:00am  Coffee  EE/CS 3176  SW11.1721.08  
9:00am10:00am  What's new in SQP methods?  Philip E. Gill (University of California, San Diego)  EE/CS 3180  SW11.1721.08 
10:00am10:30am  Coffee  EE/CS 3176  SW11.1721.08  
10:30am11:15am  Global optimization of MINLP problems containing signomial functions  Tapio Westerlund (Åbo Akademi (FinlandSwedish University of Åbo))  EE/CS 3180  SW11.1721.08 
11:15am12:00pm  A local relaxation approach for the siting of electrical substations  Uday V. Shanbhag (University of Illinois at UrbanaChampaign)  EE/CS 3180  SW11.1721.08 
12:00pm2:00pm  Lunch  SW11.1721.08  
2:00pm2:45pm  A comparative study of linear and semidefinite branchandcut methods for solving the minimum graph bisection problem  Christoph Helmberg (Technische Universität ChemnitzZwickau)  EE/CS 3180  SW11.1721.08 
2:30pm3:30pm  Math 8994: Topics in classical and
quantum mechanics Electronic structure calculations and molecular simulation: A mathematical initiation  Eric Cances (CERMICS) Claude Le Bris (CERMICS)  Lind Hall 305  
2:45pm3:10pm  Preprocessing techniques for discrete optimization problems  Todd S. Munson (Argonne National Laboratory)  EE/CS 3180  SW11.1721.08 
3:10pm3:35pm  Using expression graphs in optimization algorithms  David M. Gay (Sandia National Laboratories)  EE/CS 3180  SW11.1721.08 
3:35pm4:05pm  Coffee  EE/CS 3176  SW11.1721.08  
4:05pm5:05pm  Discussion  Tamás Terlaky (Lehigh University)  EE/CS 3180  SW11.1721.08 
8:30am9:00am  Coffee  EE/CS 3176  SW11.1721.08  
9:00am10:00am  Nonlinear discrete optimization I  Robert Weismantel (OttovonGuerickeUniversität Magdeburg)  EE/CS 3180  SW11.1721.08 
10:00am10:30am  Coffee  EE/CS 3176  SW11.1721.08  
10:30am11:15am  Nonlinear discrete optimization II  Shmuel Onn (TechnionIsrael Institute of Technology)  EE/CS 3180  SW11.1721.08 
11:15am12:15pm  TBA  Carlos J. GarciaCervera (University of California, Santa Barbara)  Vincent Hall 570  AMS 
11:15am12:00pm  On the foundations of the theory of nonLinear and multiobjective integer optimization  Jesus Antonio De Loera (University of California, Davis)  EE/CS 3180  SW11.1721.08 
12:00pm2:00pm  Lunch  SW11.1721.08  
2:00pm2:25pm  Parallelization issues for MINLP Part I  William E. Hart (Sandia National Laboratories)  EE/CS 3180  SW11.1721.08 
2:25pm2:50pm  Parallelization issues for MINLP Part II  Cynthia A. Phillips (Sandia National Laboratories)  EE/CS 3180  SW11.1721.08 
2:50pm3:35pm  MINLP application for optimizing sourcing decisions in a distressed supplier environment  Erica Zimmer Klampfl (Ford)  EE/CS 3180  SW11.1721.08 
3:35pm4:05pm  Coffee  EE/CS 3176  SW11.1721.08  
4:05pm5:05pm  Discussion  Jon Lee (IBM)  EE/CS 3180  SW11.1721.08 
6:30pm8:30pm  Workshop dinner at Pagoda Restaurant  Pagoda Restaurant 1417 4th St. SE Minneapolis, MN 6123784710 
SW11.1721.08 
8:30am9:00am  Coffee  EE/CS 3176  SW11.1721.08  
9:00am10:00am  Generalized disjunctive programming: A framework for formulation and alternative algorithms for MINLP optimization  Ignacio Grossmann (Carnegie Mellon University)  EE/CS 3180  SW11.1721.08 
10:00am10:30am  Coffee  EE/CS 3176  SW11.1721.08  
10:30am11:15am  Mixed integer second order cone programming  Sarah Drewes (TU Darmstadt)  EE/CS 3180  SW11.1721.08 
11:15am12:00pm  Solving nonconvex MINLP by quadratic approximation  Stefan Vigerske (HumboldtUniversität)  EE/CS 3180  SW11.1721.08 
12:00pm2:00pm  Lunch  SW11.1721.08  
2:00pm2:45pm  Nonlinear optimization via summation and integration  Matthias Koeppe (University of California, Davis)  EE/CS 3180  SW11.1721.08 
2:45pm3:30pm  TBA  Pablo A. Parrilo (Massachusetts Institute of Technology)  EE/CS 3180  SW11.1721.08 
3:30pm4:00pm  Coffee  EE/CS 3176  SW11.1721.08  
4:00pm5:00pm  Discussion  Tapio Westerlund (Åbo Akademi (FinlandSwedish University of Åbo))  EE/CS 3180  SW11.1721.08 
5:00pm5:05pm  Closing remark  Jon Lee (IBM) Sven Leyffer (Argonne National Laboratory)  EE/CS 3180  SW11.1721.08 
10:45am11:15am  Coffee break  Lind Hall 400  
2:30pm3:30pm  Math 8994: Topics in classical and
quantum mechanics Electronic structure calculations and molecular simulation: A mathematical initiation  Eric Cances (CERMICS) Claude Le Bris (CERMICS)  Lind Hall 305 
10:45am11:15am  Coffee break  Lind Hall 400  
3:00pm4:00pm  Reading group for Professor Ridgway Scott's book "Digital Biology"  Ridgway Scott (University of Chicago)  Lind Hall 401 
10:45am11:15am  Coffee break  Lind Hall 400  
2:30pm3:30pm  Math 8994: Topics in classical and
quantum mechanics Electronic structure calculations and molecular simulation: A mathematical initiation  Eric Cances (CERMICS) Claude Le Bris (CERMICS)  Lind Hall 305 
All Day  Thanksgiving holiday. The IMA is closed. 
All Day  Floating holiday. The IMA is closed. 
Event Legend: 

AMS  Applied Mathematics Seminar 
IPS  Industrial Problems Seminar 
PS  IMA Postdoc Seminar 
SMC  IMA Seminar on Mathematics and Chemistry 
SW11.1.08  Scientific Challenges in Solar Energy Conversion and Storage 
SW11.1721.08  MixedInteger Nonlinear Optimization: Algorithmic Advances and Applications 
T11.2.08  Physics and mathematics of multiscale modeling for chemistry and materials 
W11.37.08  Development and Analysis of Multiscale Methods 
Discussion  
Abstract: No Abstract  
Cameron F. Abrams (Drexel University)  Ligand access/escape from protein cavities: A computational study of the insulinphenol complex 
Abstract: We apply random acceleration molecular dynamics (RAMD) simulation to identify potential escape routes of phenol from hydrophobic cavities in the hexameric insulinphenol complex. We find three major pathways which provide new insights into (un)binding mechanisms for phenol. We identify several residues directly participating in escape events that serve to resolve ambiguities from recent NMR experiments. Reaction coordinates (RC) for dissociation of phenol are developed based on these exit pathways. Potentials of mean force (PMFs) along the RC for each pathway are resolved using multiple independent steered molecular dynamics (SMD) simulations with second order cumulant expansion of Jarzynski's equality. Our results for ΔF agree reasonably well within the range of known experimental and previous simulation magnitudes of this quantity. Based on structural analysis and energetic barriers for each pathway, we suggest a plausible preferred mechanism of phenolic exchange that differs from previous mechanisms. Several weaklybound metastable states are also observed for the first time in the phenol dissociation reaction.  
Denis Andrienko (MaxPlanck Institut für Polymerforschung)  Charge transport in discotic liquid crystals: a multiscale computer simulation study 
Abstract: Charge mobilities of several derivatives of discotic liquid crystals have been determined by combining three methods into one scheme: (i) quantum chemical methods for the calculation of molecular electronic structures and reorganization energies (ii) molecular dynamics for simulation of the relative positions and orientations of molecules in a columnar mesophase, and (iii) kinetic Monte Carlo simulations and Master Equation approach to simulate charge transport. We reproduce the trends and magnitudes of mobilities as measured by pulseradiolysis timeresolved microwave conductivity (PRTRMC) and connect mobility directly to the microscopic morphology of the columns. Our study also shows that it is possible to understand and reproduce experimental charge transport parameters, and, in some cases, accurately predict them.  
Kurt M. Anstreicher (University of Iowa)  The difference between 5x5 doubly nonnegative and completely positive matrices 
Abstract: The convex cone of n×n completely positive (CPP) matrices and its dual cone of copositive matrices arise in several areas of applied mathematics, including optimization. Every CPP matrix is doubly nonnegative (DNN), i.e., positive semidefinite and componentwise nonnegative. Moreover for n less than 5, every DNN matrix is CPP. We investigate the difference between 5×5 DNN and CPP matrices. We give a precise characterization of how a 5×5 DNN matrix that is not CPP differs from a DNN matrix, and use this characterization to show how to separate an extreme DNN matrix that is not CPP from the cone of CPP matrices. Joint work with Sam Burer and Mirjam Duer.  
Alán AspuruGuzik (Harvard University)  Environmentassisted quantum transport in photosynthetic complexes: Learning from nature for potential organic photovoltaic applications. 
Abstract: Transport phenomena at the nanoscale are of interest due to the presence of both quantum and classical behavior. In this work, we demonstrate that quantum transport efficiency can be enhanced by a dynamical interplay of the system Hamiltonian with the pure dephasing dynamics induced by a fluctuating environment. This is in contrast to fully coherent hopping that leads to localization in disordered systems, and to highly incoherent transfer that is eventually suppressed by the quantum Zeno effect. We study these phenomena in the FennaMatthewsOlson protein complex as a prototype for larger photosynthetic energy transfer systems. We also show that disordered binary tree structures exhibit enhanced transport in the presence of dephasing. This phenomena could in principle be applied for the development of materials with improved exciton transport properties. Our group is beginning work in this direction. If time is available, I will describe our distributed computing effort for finding novel candidates for organic photovoltaic devices by the harnessing volunteer CPU time.  
Paul J. Atzberger (University of California, Santa Barbara)  Multiscale modeling and simulation of soft matter materials 
Abstract: We shall discuss a multiscale modeling and simulation formalism for soft matter materials taking into account hydrodynamic interactions and thermal fluctuations. A specific motivation is the study of lipid bilayer membranes and polymer fluids taking into account microstructure degrees of freedom. The approach is based on the immersed boundary method, where hydrodynamic interactions of the composite system are handled by an approximate treatment of the fluidstructure stresses. The microstructures (lipid molecules / polymers) are represented by Lagrangian degrees of freedom which are coupled to an Eulerian representation of the fluid, treated at the level of continuum mechanics. Thermal fluctuations are incorporated in the formalism by an appropriate stochastic forcing of the fluidstructure equations in accordance with the principles of statistical mechanics. The theoretical formalism presents a number of numerical challenges for temporal integration and spatial resolution which we shall address. This includes a time integrator for the stiff stochastic dynamics and methods to handle adaptive spatial discretizations of the underlying stochastic partial differential equations. We shall discuss specific applications of the approach, including the study of lipid flow in bilayer membranes, the shear viscosity of polymer fluids, and the diffusivity of particles in complex fluids.  
Eray S. Aydil (University of Minnesota)  Challenges in efficient and inexpensive solartoelectric energy conversion 
Abstract: Efficient solartoelectric energy conversion with inexpensive solar cells and materials is one of the most important challenges we face in the 21st century. Crystalline silicon solar cells based on the conventional pn junction dominate the solar cell market and are commercially available in modules with 1520% efficiencies. However, they are still too expensive to manufacture which limits their potential for replacing energy from burning fossil fuels. This established technology faces the challenge of discovering innovative methods for making crystalline silicon at lower cost. Thin film solar cells based on various semiconductors such as copper indium gallium selenide (CIGS), cadmium telluride and amorphous silicon reduce the solar cell cost by reducing the amount of photovoltaic material and the amount of energy required to produce the solar cell. However, either their efficiencies are low compared to crystalline silicon or they are difficult to manufacture on large scale. In addition, last decade has produced a number of new ideas and solar cell designs based on inorganic quantum dots and on organic thin films. These ideas are now at the beginning stages of their technological evolution curves and face challenges ranging from establishing fundamental understanding of their operation principles to improving their efficiencies to levels competitive with silicon solar cells. Regardless of the solar cell technology, a number of different challenges must be surpassed to make electricity from solar energy conversion competitive with electricity obtained from burning fossil fuels. This talk will attempt to set the stage for the workshop by providing an overview of various approaches to solartoelectric energy conversion and by summarizing the scientific challenges that must be addressed to advance the state of the art in photovoltaics.  
Pietro Belotti (Lehigh University)  Branching rules in branchandbound algorithms for nonconvex mixedinteger nonlinear programming 
Abstract: For the general class of MINLP problems where relaxing the integrality on integer variables yields a nonconvex problem, a commonly used solution method is BranchandBound (BB). Two crucial components of a BB algorithm are: a convex relaxation, often an LP relaxation, to obtain lower bounds; and branching rules for partitioning the solution set. We present an extension to nonconvex MINLP of a branching technique that proved successful for MixedInteger Linear Programming, namely reliability branching. Branching rules can be applied on both integer and continuous variables in nonconvex MINLPs, and the choice of the branching variable depends on both the MINLP problem and its linear relaxation. We discuss in detail the choice of both the branching variable and the branching point, i.e. the value of that variable where branching is done. We present some computational results and compare reliability branching with another branching technique for nonconvex MINLPs, Violation Transfer, on a set of publicly available instances.  
Hande Yurttan Benson (Drexel University)  Using interiorpoint methods within MINLP 
Abstract: While implementations of infeasible interiorpoint methods remain the stateoftheart in nonlinear programming, there are serious limitations in their use within the framework of MINLP due to lack of warmstart and infeasibility detection capabilities. We present a primaldual penalty approach that allows interiorpoint methods to have such capabilities, and remains flexible enough to accommodate changing bounds, additional constraints, and additional variables in the nonlinear subproblems.  
Pierre Bonami (Centre National de la Recherche Scientifique (CNRS))  Branching strategies and heurisitcs in a branchandbound for convex MINLPs 
Abstract: Different variants of the branchandbound algorithm exist for solving exactly convex MINLPs. These variants differ mainly in the relaxation solved at the nodes of the tree. There are mainly two variants: one that solves a nonlinear programming relaxation at each node and one that solves a linear programming relaxation. In recent year the linear programming based branchandbounds have shown to be more effective on large sets of problems. In this talk, we study techniques to make the nonlinear programming based branchandbound more competitive. In particular, we study branching strategies and heuristics. The techniques have been implemented in the opensource solver Bonmin We present computational results to assess the effectiveness of the proposed strategies and compare the resulting algorithm with a linear programming (outer approximation based) branchandcut. This talk is based on joint works with Joao Goncalves, Jon Lee and Andreas Waechter.  
Andrea Braides (Seconda Università di Roma "Tor Vergata")  Variational coarsegraining of lattice systems 
Abstract: Asymptotic variational methods are aimed at describing the overall properties of an increasingly complicated system by computing an effective limit energy where some parameters are averaged out or greatly simplified. Such methods include Gammaconvergence and variational expansions. An extremely interesting field of application is that of discrete (lattice) systems, where the determination of the relevant parameters in the limit theory is part of the problem. I will present an overview of the Gammaconvergence methods and a few examples that range from nonlinear discrete homogenization to expansions in fracture mechanics to size effects in thin films to variational percolation problems.  
Frank L. H. Brown (University of California, Santa Barbara)  Simple models for biomembrane structure and dynamics 
Abstract: Simulation of biomembranes over length and time scales relevant to cellular biology is not currently feasible with Molecular Dynamics including full atomic detail. Barring an unforeseen revolution in the computer industry, this situation will not change for many decades. We present two coarse grained simulation models for biomembranes that treat water implicitly (i.e. no water molecules appear in our simulations. The hydrophobic effect, hydrodynamics and related properties are approximately included without simulation of solvent). These models enable the study of systems and phenomena previously intractable to simulation.  
Eric Cances (CERMICS), Claude Le Bris (CERMICS)  Math 8994: Topics in classical and
quantum mechanics Electronic structure calculations and molecular simulation: A mathematical initiation 
Abstract: Meeting time: Mondays and Wednesdays 2:30 ‐ 3:30 pm Room 305 Lind Hall. The course will present the basics of the quantum theory commonly used in computational chemistry for electronic structure calculations, and the basics of molecular dynamics simulations. The perspective is definitely mathematical. After the presentation of the models, the mathematical properties will be examined. The state of the art of the mathematical knowledge will be mentioned. Numerical analysis and scientific computing questions will also be thoroughly investigated. The course is intended for students and researchers with a solid mathematical background in mathematical analysis and numerical analysis. Familiarity with the models in molecular simulation in the broad sense is not needed. The purpose of the course to introduce the audience to the field. This is a 1‐3 credit course offered through the School of Mathematics. Non‐student participants are welcome to audit without registering. Note that no particular knowledge of quantum mechanics or classical mechanics will be necessary: the basic elements will be presented. For additional information and course registration, please contact: Markus Keel (keel@math.umn.edu).  
Daniel M. Chipman (University of Notre Dame)  Fermi contact interactions evaluated from hidden relations in the Schrödinger equation 
Abstract: Fermi contact interactions between electrons and nuclei govern important properties such as the hyperfine coupling constants observed in Electron Spin Resonance Spectroscopy and the spinspin coupling constants observed in Nuclear Magnetic Resonance Spectroscopy. But approximate wavefunctions of the kinds commonly used for molecules are generally optimized through some kind of overall energy criterion, and so may have significant errors for the electron density at position of a nucleus where the Fermi contact interaction occurs. It will be shown how hidden relations that are implicit in the Schrödinger equation allow the Fermi contact interactions to be reexpressed in terms of more global properties of the electron density. For exact wavefunctions the hidden relations would give the same results as would direct pointwise evaluation of the electron density, but for approximate wavefunctions the results may differ and in fact provide improved accuracy. The relevant equations will be derived, and numerical examples will be given that demonstrate the point. An extension to higher order will also be developed for the wellknown Kato cusp condition that constrains the behavior of the wavefunction  
Olivier Coulaud (Institut National de Recherche en Informatique Automatique (INRIA))  Parallel multiscale simulation for crack propagation 
Abstract: Concurrent multiscale methods are a powerful tool to solve with a low computational cost the local phenomena that occur at a small scale (atomic for example). Such methods are commonly used to study for example crack propagation, dislocations or nanoindentations. Even for small domain sizes, like the volume of a hundred nanometer cube, 3D atomistic simulations can lead to several hundred of millions atoms, and high performance parallel computation is naturally required. These simulations couple different parallel codes such as molecular dynamic code and elasticity code. The performance of the coupled code depends on how the data are well distributed on the processors. Here we focus on the parallel aspects of the Bridging Method introduced by T. Belytschko and Xiao [1]. This method assumes that an atomistic model and a continuum model are coupled through an overlap zone. We present our parallel multiscale environment called LibMultiscale [2], which is based on a coupling involving a legacy parallel code for molecular dynamics (Lammps) and a parallel finite element code for continuum mechanics (LibMesh). Data redistribution and atom migration issues are discussed. Moreover 2D and 3D waves propagation simulations and a 2D penny shape crack propagation simulation are shown. References: [1] Coupling Methods for continuum model with molecular model. T. Belytschko, S.P. Xio. International Journal for Multiscale Computational Engineering, 11 (2003). [2] LibMultiscale: http://libmultiscale.gforge.inria.fr/  
Claudia D'Ambrosio (Università di Bologna)  Water network design by MINLP 
Abstract: The optimal design of a Water Distribution Network (WDN) is a realworld optimization problem known and studied since the seventies. Several approaches has been proposed, for example, heuristics, metaheuristics, Mixed Integer Linear Programming models and global optimization methods. Despite this interest, it is still an open problem, since it is very hard to find good solutions for even medium sized instances. In this work we propose a nonconvex Mixed Integer NonLinear Programming (MINLP) model that accurately approximates the WDN problem, and we solve it with an adhoc modified branchandbound for MINLPs. This was possible thanks to the use of the opensource MINLP solver Bonmin. Computational results are presented on literature instances and new instances based on data of mediumsized Italian cities. Even for the bigger instances, we are able to find good feasible solutions. This is a joint work with C. Bragalli, J. Lee, A. Lodi and P. Toth.  
Jesus Antonio De Loera (University of California, Davis)  On the foundations of the theory of nonLinear and multiobjective integer optimization 
Abstract: In recent years algebraic geometry, number theory, and commutative algebra have shown their potential to solve challenging problems in discrete optimization. This talk hopes to show algebraic tools can be used to prove strong computational complexity results in optimization problems with nonlinear or multiobjective objective functions and linear constraints. This is talk is partly based on joint work with M. Koeppe and R. Hemmecke.  
Rafael DelgadoBuscalioni (Autonomous University of Madrid)  Atomistic, mesoscopic and continuum hydrodynamics: coupling liquid models with different resolution 
Abstract: The final goal of multiscale methods based on domain decomposition, is
to retain full atomistic
detail only where needed (within a region of interest), while using
a coarsegrained model to introduce the essential information about the
surroundings dynamics. Importantly, the atomistic region becomes an open
subsystem
which exchanges mass, momentum and energy with the exterior. The
hydrodynamics of flux exchange can be
solved using an hybrid molecularcontinuum description (hybrid MD)
[1,2]. However, molecule exchange across the hybrid interface becomes
a complicated task as one deals with more complicated molecules,
essentially owing to larger steric hindrance. A way to solve this
bottleneck is to combine hybrid MD with adaptive coarsegraining. The
setup is like the layers of an onion [3]: the atomistic model lies at
the core, surrounded by a thermodynamically compatible coarsegrained
model, which interfaces with a continuum description of the liquid
(maybe also including hydrodynamic fluctuations). Finally, open
boundary conditions for the continuum description [4] allow evacuation
of (shear, heat or sound) waves out of the whole system, and let it
behave in a grandcanonical way, in contact with the prescribed
outer thermodynamic state.
[1] G. De Fabritiis, R. DelgadoBuscalioni and P. Coveney, Phys. Rev.
Lett.97, 134501 (2006) [2] R .DelgadoBuscalioni and G. De Fabritiis, Phys. Rev. E 76, 036709 (2007) [3] R. DelgadoBuscalioni, K. Kremer and M. Praprotnik, J. Chem. Phys. 128, 114110 (2008) [4] R. DelgadoBuscalioni, A. Dejoan, Phys. Rev. E, in press, (2008) 

Luigi Delle Site (MaxPlanck Institut für Polymerforschung)  The adaptive resolution simulation scheme (AdResS): Basic principles and applications 
Abstract: For the study of complex synthetic and biological molecular systems by computer simulations one is still restricted to simple model systems or to, by far too small, time scales. To overcome this problem multiscale techniques are being developed. However in almost all cases, the regions treated at different level of resolution are kept fixed and the free exchange of particles among these regions is not allowed. I here present a robust computational method and its basic theoretical framework for an efficient and flexible coupling of the different regimes. The key feature of the method is that it allows for a dynamical change of the number of molecular degrees of freedom during the course of the MD simulation by an onthefly switching between the atomistic and coarsegrained levels of detail. Thermodynamic equilibrium is preserved by interpreting the concept of changing resolution in terms of "geometrically induced phase transition." This leads to the introduction of a "latent heat" of switching and to the extension of the equipartition theorem to fractional (switching) degrees of freedom. The efficiency of the presented approach is illustrated in the application to several systems.  
Luigi Delle Site (MaxPlanck Institut für Polymerforschung)  A criterion to estimate the quality of the Mapping Scheme in Coarsegraining approaches 
Abstract: We propose a method to evaluate the approximation of separation of variables (ASV) in Molecular Dynamics (MD) and related fields. It is based on a pointbypoint evaluation of the difference between the true potential and the corresponding potential where the separation of variables is applied. The major advantage of such an approach is the fact that it requires only the analytical form of the potential as provided in most of the MD codes. We provide an application of this criterion for alkane (aliphatic) chain and compare the efficiency for two different Mapping Schemes (MS).  
Markus Deserno (Carnegie Mellon University)  Coarsegrained simulation studies of mesoscopic membrane phenomena 
Abstract: Lipid membranes exhibit a large spectrum of fascinating physical behavior, spanning many orders of magnitude both in length and time scales. To cover this wide range, models of different resolution have been developed, from atomistically resolved lipid representations to triangulated fluidelastic surfaces. In the intermediate regime of about 100 nanometer length scale and micro to millisecond time scale mesoscopic coarsegrained models have recently covered much ground. They can approach phenomena in which cooperativity between several proteins are crucial, while still preserving the essence of many lipid degrees of freedom (area density, order, tilt, composition, etc.), whose coupling is deemed relevant in many biological situations, notably the "raft question". I will describe in more detail a particular solventfree coarsegrained model recently developed by us and illustrate its applicability to a wide variety of phenomena, among them poreformation by amphipathic peptides, protein aggregation on critically mixed bilayers, and membrane vesiculation driven by curvatureimprinting proteins.  
Belma Dogdas (Merck & Co., Inc.)  Image registration with applications in medical imaging towards drug discovery and development 
Abstract: Imaging can be used to develop effective biomarkers to provide information on diseases and assessing therapeutic effects. In the past decade, several imaging modalities have been used for early detection of drug response. Although many imaging techniques are available to the medical community, no single method provides all the necessary information. For instance structural MR and CT imaging modalities provide anatomical information whereas PET and optical imaging can provide functional information. Often, it is useful to combine complementary information from different modalities, through a technique known as image registration. In addition, statistical characterization of morphological differences within and between groups or automated identification and labeling of specific anatomical structures with an atlas requires image registration. Therefore it is essential to understand image registration techniques to enable their effective use in imaging applications. In this talk, I will describe recent advances in image registration and provide examples of how it is being used in medical imaging towards drug discovery and development.  
Sarah Drewes (TU Darmstadt)  Mixed integer second order cone programming 
Abstract: We present two algorithms to solve mixed integer secondorder cone programming problems: a branchandcut method and an outer approximation based branchandbound approach. We use different techniques for the generation of linear and convex quadratic cuts and investigate their impact on the branchandcut procedure. The presented outer approximation based branchandbound algorithm is an extension of the wellknown outer approximation based branchandbound approach for continuous differentiable problems to subdifferentiable constraint functions. Convergence can be guaranteed, since the subgradients, that satisfy the KKT conditions, can be identified using the dual solution of the occurring second order cone problems. Computational results for test problems and real world applications are given.  
Burkhard Dünweg (MaxPlanck Institut für Polymerforschung)  Lattice Boltzmann simulations of softmatter systems 
Abstract: A brief introduction into the lattice Boltzmann method is given. For softmatter applications, it is necessary to include thermal fluctuations by introducing stochastic collision rules. This can be done consistently based upon the concept of detailed balance. Brownian particles are coupled to the lattice Boltzmann solvent via a Stokes friction and interpolation. The Langevin equations of the overall system satisfy both momentum conservation and the fluctuationdissipation theorem. The longtime mobility of the particles differs from the input Stokes value by a contribution from the surrounding flow. The usefulness of this method is demonstrated by examples from polymer physics (hydrodynamic screening of semidilute polymer solutions) and colloid physics (electrophoresis of chargestabilized colloidal dispersions).  
Burkhard Dünweg (MaxPlanck Institut für Polymerforschung)  Basic concepts of polymer physics and their numerical study 
Abstract: Polymers are prototypical examples of softmatter systems. The talk will first focus on equilibrium statistical mechanics, and introduce basic concepts like the random walk and the selfavoiding walk. This is complemented by a discussion of the notion of coarsegraining and scale invariance, which is at the basis of modeling polymers in terms of simple beadspring models. The second part will then discuss the basics of polymer dynamics, in terms of the fundamental Rouse, Zimm, and reptation models. The third part is devoted to a brief overview over Monte Carlo and Molecular Dynamics models and simulation algorithms, which are directly based upon the insight into the essential physics. If time permits, a brief outlook on the physics of membranes will be added.  
Weinan E (Princeton University)  Some representative issues in multiscale modeling 
Abstract: I will discuss the mathematical and numerical problems involved in coupling atomistic and continuum models as well as coupling electronic and atomistic models, with examples from materials and fluids.  
Weinan E (Princeton University)  Capturing the macroscopic behavior of complex systems using multiscale methods 
Abstract: Joint work with Eric VandenEijnden. In many problems of multiscale modeling, we are interested in capturing the macroscale behavior of the system with the help of some accurate microscale models, bypassing the need of using empirical macroscale models. This paper gives an overview of the recent efforts on establishing general strategies for designing such algorithms. After reviewing some important classical examples, the CarParrinello molecular dynamics, the quasicontinuum method for modeling the deformation of solids and the kinetic schemes for gas dynamics, we discuss three attempts that have been made for designing general strategies: Brandt's renormalization multigrid method (RMG), the heterogeneous multiscale method (HMM) and the "equationfree" approach. We will discuss the relative merits and difficulties with each strategy and we will make an attempt to clarify their similarities and differences. We will then discuss a general strategy for developing seamless multiscale methods for this kind of problems. We will end with a discussion of the applications to free energy calculations and a summary of the challenges that remain in this area  
Bjorn Engquist (University of Texas)  Finding effective equations for heterogeneous multiscale methods 
Abstract: An advantage with the framework of the heterogeneous multiscale method is that the full knowledge of an effective or macroscale equation is not required for the numerical approximation of a homogenized or averaged solution. A higher fidelity microscale model is used to supply the missing data. The efficiency is gained by only applying the microscale model in sub domains. The structure of the macroscale equation must however be known. Often it is well known from the setting of the original problem, but if it is not, new techniques are required to find the form of a relevant effective or macroscale equation.  
James W. Evans (Iowa State University)  Realistic multiscale modeling of spatiotemporal behavior in surface reactions: Equationfree "heterogeneous coupled latticegas" (HCLG) simulations 
Abstract: A rich variety of spatiotemporal pattern formation and reaction front propagation has been observed in simple reactions on metal surfaces. Modeling has typically applied meanfield reactiondiffusion equations  ignoring the impact of reactant ordering or islanding on the reaction kinetics, and oversimplifying the treatment of surface diffusion in mixed reactant adlayers. In 1995, we introduced an equationfree HCLG simulation approach [Tammaro et al. J. Chem. Phys. 103 (1995) 10277] which performs parallel KMC simulations of an atomistic latticegas reaction model at spatial locations distributed across the surface, and suitably couples these to describe the effects of macroscopic surface diffusion. Recently, we have applied this approach to realistic models for COoxidation on Pd(100) and Rh(100) surfaces [Liu & Evans, Phys. Rev. B 70 (2004) 193408; Surf. Sci.  Ertl Nobel Issue 2008]. This requires a precise treatment of the collective and "tensorial" nature of the rapid diffusion of CO through a disordered environment of relatively immobile oxygen [Liu & Evans, J. Chem. Phys. 125 (2006) 054709].  
Roland Faller (University of California, Davis)  Multiscale modeling of polystyrene in different environments 
Abstract: Polystyrene is a very abundant and industrially important polymer. We are modeling its dynamical behavior on multiple length scales and different environments. We start with pure PS where we develop a mesoscale polystyrene model based on atomistic simulations. The nonbonded effective potential is optimized against the atomistic simulation until the radial distribution function generated from the mesoscale model is consistent with the atomistic simulation. The mesoscale model allows understanding the polymer dynamics of long chains in reasonable computer time. Both models are investigated in the melt, the blend and in confined geometries. The dynamics of polystyrene melts are investigated at various chain lengths ranging from 15 to 240 monomers and the crossover to entangled dynamics is observed. As computer simulations cannot only address average properties of the system under study but also the distribution over any observable of interest we are study mixtures of polystyrene and polyisoprene by atomistic molecular dynamics and calculate correlation times for all segments in the system. We then identify fast and slow segments and can correlate the segment speed with the local neighborhood and obtain that fast segments have a surplus of the faster component in their neighborhood and vice versa. Finally we present a coarse grained model for the blend which is capable of showing phase separation.  
Roland Faller (University of California, Davis)  Multiscale modeling of structure and phase behavior in heterogeneous lipid bilayers 
Abstract: The study of lipid structure and phase behavior at the nano scale length is of importance due to implications in understanding the role of the lipids in biochemical membrane processes. We performed a variety of simulations in homogeneous and heterogeneous membrane systems to elucidate such behaviors. Our simulations demonstrate that various coarse grained simulation models can predict different aspects of lipid phase separation and describe the change of the system under the influences of hydrophilic and hydrophobic support. The simulations are performed using models at different length scales ranging from the all atom scale to a scale where lipids are modeled by only three interaction sites. We are able to follow transformations, such as lipids phase transitions. These phase transitions are determined by analyzing parameters like area per lipid head group, the deuterium order parameter and dynamic properties. Phase diagrams of mixtures are reproduced consistent with experiments. We study the influence of a support on the systems on different length scales. We discuss the changes of the system phase behavior as well as differences between the two leaflets as induced by the support.  
Dominik Fritz (Max Planck Institute for Polymer Research)  From atomistic to mesoscale systems without fitting: A coarse grained model for polystyrene 
Abstract: We present a coarse grained model for polystyrene, which is only based on properties of single chains and of systems consisting of two short oligomers. We do not need any fitting to atomistic melt simulations. The model keeps the information about the tacticity of the chains and reproduces the local distributions for bond length, angles and dihedral angles. Furthermore it is modeling statical properties of atomistic melts, e.g. radial distribution functions and internal distances.  
David M. Gay (Sandia National Laboratories)  Using expression graphs in optimization algorithms 
Abstract: An expression graph, informally speaking, represents a function in a way that cam be manipulated to reveal various kinds of information about the function, such as its value or partial derivatives at specified arguments and bounds thereon in specified regions. (Various representations are possible, and all are equivalent in complexity, in that one can be converted to another in time linear in the expression's size.) For mathematical programming problems, including the mixedinteger nonlinear programming problems that are the subject of this workshop, there are various advantages to representing problems as collections of expression graphs. "Presolve" deductions (to be discussed in more detail by Todd Munson) can simplify the problem, e.g., by reducing the domains of some variables and proving that some inequality constraints are never or always active. To find global solutions, it is helpful sometimes to solve relaxed problems (e.g., allowing some "integer" variables to vary continuously or introducing convex or concave relaxations of some constraints or objectives), and to introduce "cuts" that exclude some relaxed variable values. There are various ways to compute bounds on an expression within a specified region or to compute relaxed expressions from expression graphs. This talk will sketch some of them. As new information becomes available in the course of a branchandbound (or cut) algorithm, some expressiongraph manipulations and presolve deductions can be revisited and tightened, so keeping expression graphs around during the solution process can be helpful. Algebraic problem representations are a convenient source of expression graphs. One of my reasons for interest in the AMPL modeling language is that it delivers expression graphs to solvers.  
Johannes Giannoulis (Technical University of Munich )  From quantum to classical molecular dynamics 
Abstract: We are interested in the rigorous justification of the passage from quantum to classical molecular dynamics in the heavy nuclei limit, i.e., when the mass ratio of elecronic to nucleonic mass tends to zero. For positive mass ratio the (nonrelativistic) quantum dynamics is described by the timedependent linear Schroedinger equation, where the potential U is the ground state BornOppenheimer potential energy surface obtained by minimization over electronic states. The classical dynamics is governed by the Liouville equation for an (appropriately defined) timedependent Wigner measure W, obtained as the limit (for mass ratio tending to zero) of the Wigner functions corresponding to the wavefunctions solving the Schroedinger equation. Since the physically correct potential U possesses Coulomb singularities due to nuclei repulsion and can have kink type singularities if eigenvalue crossings are present, its level of smoothness is far lower than that required in previous rigorous approaches and renders the justification of the Liouville equation quite difficult. In the poster we present our results mainly concerning the case of potentials U with only Coulomb singularities and no crossings.  
Philip E. Gill (University of California, San Diego)  What's new in SQP methods? 
Abstract: Sequential quadratic programming (SQP) methods a powerful and effective class of methods for a wide range of nonlinearly constrained optimization problems. Given the scope and utility of nonlinear optimization, it is not surprising that SQP methods are still a subject of active research. Recent developments in methods for mixed integer nonlinear programming and the minimization of functions subject to differential equation constraints has led to a heightened interest in methods that may be "hot started" from a good approximate solution. We discuss the role of SQP methods in this context, with particular reference to some recent enhancements to our largescale SQP package SNOPT. We end with some discussion of the challenges associated with formulating algorithms that can exploit multicore and GPUbased computer architectures.  
Ignacio Grossmann (Carnegie Mellon University)  Generalized disjunctive programming: A framework for formulation and alternative algorithms for MINLP optimization 
Abstract: Generalized disjunctive programming (GDP) is an extension of the disjunctive programming paradigm developed by Balas. The GDP formulation involves Boolean and continuous variables that are specified in algebraic constraints, disjunctions and logic propositions, which is an alternative representation to the traditional algebraic mixed integer programming (MIP) formulation. Our research on GDP problems has been motivated by its potential for improved modeling of MINLP optimization, and for the development of customized algorithms that exploit the underlying logical structure of the problem in both the linear and nonlinear cases. We first provide an overview of this work for the case of convex functions emphasizing the quality of continuous relaxations of alternative reformulations that include the bigM, the hull relaxation and the sequential intersection of disjunctions. We then review disjunctive branch and bound as well as logicbased decomposition methods that circumvent some of the limitations in traditional MINLP optimization. Finally, for the case when the GDP problem involves nonconvex functions, we propose a scheme for tightening the lower bounds for obtaining the global optimum using a combined disjunctive and spatial branch and bound search. We illustrate the application of the theoretical concepts and algorithms on a variety of engineering and OR problems.  
William E. Hart (Sandia National Laboratories)  Parallelization issues for MINLP Part I 
Abstract: Sandia National Laboratories has invested considerable effort in massively parallel optimization tools. In this talk, we will summarize relevant experience from developing our parallel mixedinteger programming (MIP) solver PICO (Parallel Integer and Combinatorial Optimizer) and our parallel nonlinear solver GNLP. We will discuss parallel solution of mixedinteger nonlinear programs (MINLP). In particular, we will consider how the choice of parallel platform (tightlycoupled systems, cloud computing, grid computing, etc) can affect algorithmic decisions. We will highlight issues parallel solvers must face that serial solvers do not such as load balancing, ramp up, and termination and some issues that parallel solvers might do differently, such as decomposition. We expect some of our MIP/NLP experience to carry over, and some issues to be unique to, or uniquely difficult for, MINLP.  
Teresa HeadGordon (University of California, Berkeley)  Coarsegrained and multiscale models of bulk liquids and macromolecules 
Abstract: I will describe two coarsegrained models and a multiscale model relevant in the context of molecular or langevin dynamics of bulk liquids and macromolecules. We have recently achieved a fundamental result in deriving an analytical solution for computing the screened electrostatic interaction between arbitrary numbers of proteins of arbitrarily complex charge distributions, assuming they are well described by spherical low dielectric cavities in a higher dielectric salty medium [1]. Ultimately, smooth and systematic increase or decrease in spatial resolution back and forth between simple dielectric cavities and atomic level descriptions will be the centerpiece of a multiscale scheme [2]. I will also describe a coarsegrained model of water to investigate thermodynamicdynamic relationships [3] as well as a coarsegrained protein model relevant for lengthscales and timescales relevant for disease aggregation [4, 5]. [1] I. Lotan & T. HeadGordon (2006). An analytical electrostatic model for salt screened interactions between multiple proteins J. Comp. Theo. Chem. 2, 541555. [2] E.H. Yap & T.HeadGordon (2008). In progress [3] M.E. Johnson and T. HeadGordon (2008). Thermodynamic theories of liquid dynamics. submitted. [4] E.H. Yap, N. Lux Fawzi & T. HeadGordon (2008). A coarsegrained acarbon protein model with anisotropic hydrogenbonding. Proteins, Struct. Func.. Bioinf. 70, 626638. [5] N. Lux Fawzi, E.H. Yap, Y. Okabe, K. Kohlstedt, S. P. Brown & T. HeadGordon (2008). Contrasting disease and nondisease protein aggregation. Acc. Chem. Research 41, 10371047.  
Christoph Helmberg (Technische Universität ChemnitzZwickau)  A comparative study of linear and semidefinite branchandcut methods for solving the minimum graph bisection problem 
Abstract: Joint work with Michael Armbruster (TU Chemnitz), Marzena Fuegenschuh (TU Darmstadt), and Alexander Martin (TU Darmstadt). Semidefinite relaxations are known to deliver good approximations for combinatorial optimization problems like graph bisection. Using the spectral bundle method it is possible to exploit structural properties of the underlying problem and to apply, even to sparse large scale instances, cutting plane methods, probably the most successful technique in linear programming. We set up a common branchandcut framework for linear and semidefinite relaxations of the minimum graph bisection problem. It incorporates separation algorithms for valid inequalities presented in the recent study by Armbruster, Fuegenschuh, Helmberg, and Martin 2007 of the facial structure of the associated polytope. Extensive numerical experiments show that the semidefinite branchandcut approach outperforms the classical simplex approach on a clear majority of the sparse large scale test instances. On instances from compiler design the simplex approach is faster.  
Russell J. Holmes (University of Minnesota)  Engineering morphology in small molecule organic photovoltaic cells for efficient exciton diffusion and dissociation 
Abstract: Organic materials are attractive for application in photovoltaic cells due to their compatibility with lightweight, flexible substrates, and highthroughput processing techniques. Optical absorption in these materials leads to the creation of a bound electronhole pair known as an exciton. The exciton is mobile, and diffuses to a heterojunction where electronhole dissociation and photocurrent generation may take place. In most organic materials, the exciton diffusion length is much shorter than the optical absorption length. This “exciton bottleneck” limits the active layer thickness and reduces the absorption efficiency of the cell. Routes around the bottleneck have centered on the use of mixed donoracceptor morphologies to increase the area of the dissociating interface. While promising, these architectures are difficult to optimize, and can introduce resistance for the collection of photogenerated carriers. This talk will examine an alternate approach to overcome the exciton bottleneck, focusing on the use carefully controlled, graded morphologies in organic photovoltaics.  
Richard D. James (University of Minnesota)  A mathematical perspective on the structure of matter 
Abstract: Beginning with some observations about the periodic and nonperiodic structures commonly adopted by elements in the periodic table, I will introduce a definition ("objective structures") of a mathematically small but physically well represented class of molecular structures. This definition will be seen to have an intimate relation to the invariance of the equations of quantum mechanics. The resulting framework can be used to design various multiscale methods, and gives a new perspective on some of the fundamental solutions in continuum mechanics for solids and fluids. Open mathematical problems will be highlighted.  
Christoph Junghans (MaxPlanck Institut für Polymerforschung)  Comparative study of water: Atomistic vs. coarsegrained 
Abstract: We employ the inverse Boltzmann method to coarsegrain three commonly used three site water models (TIP3P, SPC and SPC/E) where one molecule is replaced by one coarsegrained particle with two body interactions only. The shape of the coarsegrained potentials is dominated by the ratio two lengths, which can be rationalized by the geometric constraints of the water clusters. It is shown that for simple two body potentials either the radial distribution function or the geometrical packing can be optimized. In a similar way, as needed for multiscale methods, either the pressure or the compressibility can be fitted to the all atom liquid. In total, a speedup of a factor of about 50 in computation time can be reached by this coarsegaining procedure.  
Raymond Kapral (University of Toronto)  Molecular dynamics in mesoscopic solvents 
Abstract: Modeling the dynamics of complex molecular systems is difficult since physically relevant distance and time scales are often very long. Consequently, a variety of different coarsegrained molecular dynamics methods, which attempt to bridge gap between short and long scales, has been developed. The talk will focus one such method, multiparticle colision dynamics, for the computation of the mesoscopic dynamics of molecular systems. In particular, polymer and biopolymer dynamics in crowded molecular environments, such as those encountered in the interior of the cell, and the motion of selfpropelled nanoparticles in solution will be considered. The mesoscopic simulations were carried out by combining a molecular dynamics description of the molecular with a coarse grained description of the solvent using multiparticle collision dynamics.  
Andreas G. Karabis (PI Medical Ltd)  HIPO: A nonlinear mixed integer constrained optimization algorithm for treatment planning in brachytherapy 
Abstract: Joint work with Stavroula Giannouli (Pi Medical) and Dimos Baltas (Klinikum Offenbach GmbH, Germany). HIPO (Hybrid Inverse Planning and Optimization) is a general, stateoftheart treatment planning optimization tool with inverse planning capabilities for interstitial template based brachytherapy. HIPO was presented in 2005 and the first commercial release was launched in 2007. It is used in more than 30 clinics around the world. An improved version is presented here, able to take into account clinical recommendations as soft & hard constrains. During the templatebased brachytherapy treatment procedure, a perforated template is fixed on patient’s body and needles are placed through the holes inside patient’s body, penetrating the tumour. Within the needles, an irradiating source is stepping. The total dose distribution in the tumour, the surrounding organs and tissue, is a function of the times (dwell times) that the source is spending at each position. The main purpose of planning is to irradiate the target while protecting the surrounding healthy tissues. The problem that the planer has to solve, is to define the optimal positions (binary variables) of a predefined number of catheters on the template, and then to optimize the dose distribution by adapting the dwell times (continuous variables). Typical numbers of template holes and required catheters can easily result to O(10^{12}) possible combinations. This problem can be formulated as a mixed integer nonlinear programming (MINLP) problem, where each combination requires the solution of a continuous nonlinear optimization problem. Furthermore, the clinical requirements that the planers are typically following (e.g. GECESTRO recommendations) can be handled as soft or hard constrains. HIPO is giving a near optimal solution in relatively short time (typically 0.55min), convenient for realtime planning in the operation room. A hybrid algorithm, based on Simulated Annealing and a problemspecific, deterministic heuristic, is used for the binary optimization problem of catheter positioning. The problemspecific heuristic is incorporating expert knowledge. The continuous dose optimization for each set up of the catheters is solved by the standard LBFGS algorithm.  
Mikko Karttunen (University of Western Ontario)  Coarsegraining of cholesterol containing lipid bilayers 
Abstract: I will discuss multiscale modeling of biological membranes. The approach is based on the socalled Inverse Monte Carlo (IMC) method and the Henderson theorem. The specific examples [1] will include single and multicomponent bilayers using different levels of coarsegraining, and the improvent of accuracy of the coarsegrained models by using a thermodynamic constraint. The motivation for including a constraint is that the basic IMC does not yield physically meaningful area compressibility or surface tension in coarsegrained bilayers. The results using cholesterol containing systems show formation of denser transient regions, resembling lipid rafts, which is in accord with observations from microscopic models. Finally, I will discuss some of the advantages and disadvantages of this approach. References: [1] T. Murtola, E. Falck, M. Patra, M. Karttunen, I. Vattulainen, J. Chem. Phys. 121:91569165  
Toshihiro Kawakatsu (Tohoku University)  Development of dynamic density functional theories of multiphase dense polymeric systems 
Abstract: We present the results of our recent developments of multiscale modelling on dynamics of phase separation and phase transition in multiphase dense polymeric systems. Our modeling is based on density functional theories of polymeric systems, such as the selfconsistent field (SCF) theory and the GinzburgLandau (GL) theory. We combine these theories with flow dynamics, diffusion dynamics, and the effects of external fields such as a flow field, electric field, and confinements.  
Erica Zimmer Klampfl (Ford)  MINLP application for optimizing sourcing decisions in a distressed supplier environment 
Abstract: Ford was tasked with determining the best sourcing footprint for its $1.5 billion Automotive Components Holdings, LLC Interiors business. This extensive undertaking required a complete reengineering of the supply footprint of 42 highvolume product lines over 26 major manufacturing processes and more than 50 potential supplier sites. We propose an approximation of the largescale Mixed Integer Nonlinear Program (MINLP) that accurately accommodates the nonlinear nature of facility cost as a function of utilization and present an iterative Mixed Integer Program (MIP) approach to solve the underlying MINLP. We demonstrate that the resulting solution to the iterative algorithm provides an equivalent solution to the approximated MINLP. The recommendations from this work have been implemented in practice and have resulted in savings of approximately $40 million in upfront investment over the previously preferred alternative.  
William S. Klug (University of California, Los Angeles)  Multiscale structural mechanics of viruses: Stretching the limits of continuum modeling 
Abstract: The last several years have seen a number of successful applications of continuum elasticity theory to the study of virus mechanics. Continuum modeling has been particularly effective in connection with atomic force microscopy nanoindentation experiment for understanding and predicting material properties of viral shells (capsids), and may hold promise for illuminating the physics of capsid assembly as well. I will consider the question of the limitations of continuum modeling of capsids, and discuss some examples of how conventional continuum theory is being extended or "stretched" to study multiscale features linked to the inherently discrete character of these molecular assemblies.  
William S. Klug (University of California, Los Angeles)  Techniques for coarsegrained modeling and mechanics of viral capsids 
Abstract: As revealed by techniques of structural biology and singlemolecule experimentation, the capsids of viruses are some of nature's best examples of highly symmetric multiscale selfassembled structures with impressive mechanical properties of strength and elasticity. We present a novel method for creating threedimensional finite element meshes of viral capsids from both atomic data from PDB files and electron density data from EM files. The meshes capture heterogeneous geometric features and are used in conjunction with threedimensional continuum elasticity to simulate nanoindentation experiments as performed using atomic force microscopy. Meshes and nanoindentation simulations are presented for several viruses: Hepatitis B, CCMV, HK97, and Phi 29.  
Matthias Koeppe (University of California, Davis)  Nonlinear optimization via summation and integration 
Abstract: The classic idea to relate the maximum of a function over a discrete or continuous domain to certain sums or integrals has made its apppearance in a number of recent papers from the point of view of optimization (A.I. Barvinok, "Exponential integrals and sums over convex polyhedra", Funktsional. Anal. i Prilozhen. 26 (1992); J.B. Lasserre, "Generating functions and duality for integer programs", Discrete Optim. 1 (2004)). Efficient summation and integration procedures can give rise to efficient approximation algorithms for optimization problems. As an example, a fully polynomialtime approximation scheme for optimizing arbitrary polynomial functions over the integer points in polyhedra of arbitrary, fixed dimension has been obtained (work with J. A. De Loera, R. Hemmecke, R. Weismantel, Math. Oper. Res. 31 (2006)). In this talk I report on recent work (with V. Baldoni, N. Berline, J. A. De Loera, M. Vergne) to study the efficiency of integration procedures for polynomial functions in high dimension. The methods are related to Brion's formulas, Barvinok's exponential sums, and also to the polynomial Waring problem that asks to represent a polynomial as a sum of powers of few linear forms.  
Claude Le Bris (CERMICS)  Positive temperature coarsegraining of onedimensional systems 
Abstract: We present a possible approach for the computation of free energies and ensemble averages of onedimensional coarsegrained models in materials science. The approach is based upon a thermodynamic limit process, and makes use of ergodic theorems and large deviations theory. In addition to providing a possible efficient computational strategy for ensemble averages, the approach allows for assessing the accuracy of approximations commonly used in practice. This is joint work with X. Blanc (University Paris 6), F. Legoll (ENPCINRIA) and C. Patz (WeierstrassInstitut, Berlin), submitted to journal of nonlinear science, preprint available at http://hal.inria.fr/inria00282107/en/.  
Frédéric Legoll (École Nationale des PontsetChaussées)  Effective dynamics using conditional expectations 
Abstract: We consider a system described by its position X_{t}, that evolves according to the overdamped Langevin equation. At equilibrium, the statistics of X are given by the BoltzmannGibbs measure. Suppose that we are only interested in some given lowdimensional function ξ(X) of the complete variable (the socalled reaction coordinate). The statistics of ξ are completely determined by the free energy associated to this reaction coordinate. In this work, we try and design an effective dynamics on ξ, that is a lowdimensional dynamics which is a good approximation of ξ(X_{t}). Using conditional expectations, we build an original dynamics, and discuss how it is related to the free energy itself. Using an entropybased approach, we are also able to derive error estimates. Numerical simulations will illustrate the accuracy of the proposed dynamics. Joint work with T. Lelievre (ENPC and INRIA).  
Leo Liberti (École Polytechnique)  Reformulations in mathematical programming: Symmetry 
Abstract: If a mathematical program (be it linear or nonlinear) has many symmetric optima, solving it via BranchandBound techniques often yields search trees of disproportionate sizes; thus, finding and exploiting symmetries is an important task. We propose a method for: (a) automatically finding the formulation group of any given MixedInteger Nonlinear Program, and (b) reformulating the problem so that it has fewer symmetric solutions. The reformulated problem can then be solved via standard BranchandBound codes such as CPLEX (for linear programs) and Couenne (for nonlinear programs). Our computational results include formulation group tables for the MIPLib3, MIPLib2003, GlobalLib, MINLPLib and MacMINLP instance libraries, solution tables for some instances in the aforementioned libraries, and a theoretical and computational study of the symmetries of the Kissing Number Problem.  
Jeff Linderoth (University of Wisconsin)  Building an effective solver for convex mixed integer nonlinear programs 
Abstract: The most effective solvers for mixed integer linear programs (MILP)s employ a variety of algorithmic refinements that have made previously intractable models routinely solvable. Solvers for Mixed Integer Nonlinear Programs (MINLP)s should be no different. In this talk, we will discuss the impact of applying advanced branching rules, primal heuristics, preprocessing, and cutting planes in algorithms to solve (convex) mixed integer nonlinear programs. Many of the ideas have been implemented in the solver FilMINT, and the talk contains computational results to demonstrate the improvements that can be obtained by applying traditional MILP techniques for MINLPs.  
Alexander Lukyanov (MaxPlanck Institut für Polymerforschung)  Force matching versus structural coarsegraining 
Abstract: Joint work with Victor Rühle and Denis Andrienko (Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany). We are working on a detailed comparison of two coarsegraining methods, force matching [1] and iterative inverse Boltzmann [2]. Force matching is generalized for coarsegraining of angle and dihedral potentials, in addition to standard bond stretching and nonbonded interactions. Some initial steps are made in order to develop solventfree coarsegraining models for polymers in solutions for systems of a particular importance for organic electronics (soluble conjugated polymers). 1. S. Izvekov, G. Voth „Multiscale coarse graining of liquidstate systems“, J. Chem. Phys. 123, 134105 (2005) 2. W. Tschoep, K. Kremer, J. Batoulis, T. Buerger and O. Hahn, Acta Polym 49, 61 (1998)  
Mitchell Luskin (University of Minnesota)  Predictive and efficient quasicontinuum methods 
Abstract: The development of predictive and efficient atomistictocontinuum computational methods requires both an analysis of the error and efficiency of its many components (coupling method, model and mesh adaptivity, solution methods) as well as its integration into an efficient code capable of solving problems of technological interest. There are many choices available for the interaction between the representative atoms of the quasicontinuum method, especially between those in the atomistic and continuum regions, which has led to the development of a variety of quasicontinuum approximations. We will present criteria for determining a good choice of quasicontinuum approximation that considers tradeoffs between accuracy and algorithmic efficiency. Our criteria are based on the effect of the coupling error on the goal of the computation, on the integration of the quasicontinuum approximation with model and mesh adaptivity, and on the development of efficient iterative solution methods. Joint Work with Marcel Arndt, Matthew Dobson, Ron Miller, Christoph Ortner, and Ellad Tadmor.  
Alex Marker (Schott North America, Inc.)  Receiver technology for today and tomorrow 
Abstract: No Abstract  
Jesús MartínVaquero (University of Salamanca)  A new procedure to building stabilized explicit RungeKutta methods for large systems of ODEs 
Abstract: Joint work with B. Janssen and B. Wade. Stabilized RungeKutta methods (or ChebyshevRungeKutta methods) are explicit methods with extended stability domains, usually along the negative real axis. They are easy to use (they do not require algebra routines) and they are especially suited for MOL discretizations of two and three dimensional parabolic partial differential equations. However, existing codes have some difficulties in cases when the eigenvalues are very large. We have developed a new procedure to build this kind of algorithm and derive secondorder methods with up to 320 stages, all with good stability properties. These methods are efficient numerical integrators of very large stiff ordinary differential equations. Applications to the numerical solution of reactiondiffusion problems will be presented.  
Vlasis George Mavrantzas (University of Patras)  Quantifying chain reptation in entangled polymers by mapping atomistic simulation results onto the tube model 
Abstract: The topological state of entangled polymers has been analyzed recently in terms of primitive paths which allowed obtaining reliable predictions for the static (statistical) properties of the underlying entanglement network for many polymeric systems. Through a systematic methodology that first maps atomistic molecular dynamics trajectories onto time trajectories of primitive paths and then documents primitive path motion in terms of a onedimensional curvilinear diffusion in a tubelike region around the coarsegrained chain contour, we further extend these static approaches by computing the most fundamental function of the reptation theory, namely the probability that a segment s of the primitive chain remains inside the initial tube after time t. Linear viscoelastic properties, such as the zero shear rate viscosity and the spectra of storage and loss moduli, obtained on the basis of the obtained curves, for three different polymer melts (polyethylene, cis1,4polybutadiene and trans1,4polybutadiene) agree remarkably well with experimental rheological data. The new methodology is general and can be routinely applied to analyze primitive path dynamics and chain reptation in atomistic trajectories (accumulated through computer simulations) of other model polymers or polymeric systems (e.g., bidisperse, branched, grafted, etc); it is thus believed to be particularly useful in future theoretical developments of more accurate tube theories for entangled systems.  
Todd S. Munson (Argonne National Laboratory)  Preprocessing techniques for discrete optimization problems 
Abstract: Preprocessing technique simplify and strengthen a model prior to calculating a solution. A combination of rules exploiting the constraint set and primaldual relationships are applied to fix variables, improve their bounds, and eliminate redundant expressions. In addition, some nonconvex constraints can be transformed into convex constraints. Exploiting discrete variables during preprocessing adds rules to identify and exploit special structures and strengthen the formulation prior to computing convex estimators and cuts, and exploring a branchandbound tree. In this talk, I will discusses a unified preprocessor for mixed integer mathematical programs with equilibrium constraints being developed for MINOTAUR.  
Marcus Müller (GeorgAugustUniversität zu Göttingen)  Soft coarsegrained models for multicomponent polymer melts: free energy and singlechain dynamics 
Abstract: In soft, coarsegrained models for dense polymer liquids, harsh repulsive interactions (excluded volume) between segments are replaced by soft repulsive interactions, which are sufficient to suppress density fluctuations. These models allow to efficiently study polymer melts with an experimentally relevant invariant degree of polymerization by computer simulation. Two topics will be discussed: (i) The calculation of free energies in selfassembling systems will be illustrated by studying the interface free energy of two lamellar grains of a symmetric diblock copolymer melt with perpendicular orientation (Tjunction). (ii) The softness of the segmental interactions in coarsegrained models does not guarantee noncrossability of the molecules during the course of their motion. The effect of these topological constraints, which lead to reptation dynamics in dense melts of long flexible molecules, can be mimicked by sliplinks and application of sliplinks to the singlechain dynamics in the disordered and lamellar phase will be discussed.  
Giacomo Nannicini (École Polytechnique)  Variable neighbourhood search for MINLPs 
Abstract: In a recent work we presented a generalpurpose heuristic for (nonconvex) MINLPs based on Variable Neighbourhood Search, Local Branching, Sequential Quadratic Programming and BranchandBound, combining several commercial solvers together. That method, which we called RECIPE, turned out to be very effective on the majority of the test instances, finding solutions at least as good as the best known optima for 55% of the MINLPLib. We analyse the computational performance of RECIPE when relying on opensource solvers only. Moreover, we study the effect of iiteratively applying a bound tightening phase throughout the algorithm.  
Jorge Nocedal (Northwestern University)  Fast infeasibility detection in nonlinear optimization 
Abstract: An important issue in branch and bound methods for mixed integer nonlinear programming is the fast detection of infeasibility. This topic has not received sufficient attention and the methods developed for nonlinear programming often required a large number of iterations before a declaration of infeasibility can be made. The focus of this talk is to address the need for optimization algorithms that can both efficiently solve feasible problems and rapidly detect when a given problem instance is infeasible. One way to address these concerns is to employ a switch in an algorithm to decide whether the current iteration should seek a solution of the nonlinear program or, in contrast, to solely minimize some measure of feasibility. A challenge with such an approach lies in the difficulty of designing effective criteria for determining when such a switch should be made. We propose an alternative approach involving a single optimization strategy, and show that it is effective for finding an optimal feasible solution (when one exists) or finding the minimizer of a feasibility measure (when no feasible point exists). Our algorithm is an activeset method that uses the penalty parameter to emphasize optimality over infeasibility detection, or vice versa. We establish superlinear convergence results and discuss numerical experiments that demonstrate the advantages of our approach.  
William G. Noid (Pennsylvania State University)  A rigorous multiscale bridge connecting atomistic and coarsegrained models 
Abstract: Coarsegrained (CG) models provide a promising computational tool for investigating slow complex processes that cannot be adequately studied using more detailed models. However, unless the CG model is consistent with an accurate highresolution model, the results of CG modeling may be misleading. The present talk describes a statistical mechanical framework that provides a rigorous “multiscale bridge” connecting models with different resolution. In particular, this framework provides a formal definition of consistency and a systematic computational methodology for constructing a coarsegrained (CG) model that is consistent with a particular atomistic model. The cornerstone of this approach is a variational principle for calculating a manybody potential of mean force, which is the appropriate potential for such a consistent CG model. The multiscale coarsegraining method employs this variational principle by numerically calculating the projection of the atomistic force field onto the subspace of CG force fields spanned by a given set of basis vectors. Because typical CG force field basis vectors correspond to correlated molecular interactions, these basis vectors are not orthogonal and, consequently, manybody correlation functions must be explicitly treated. The present talk describes this development, presents numerical applications for molecular systems, and demonstrates how this framework may be employed to develop transferable CG interaction potentials.  
Arthur J. Nozik (Department of Energy)  Multiple exciton generation in semiconductor quantum dots and novel molecules: Applications to third generation solar photon conversion 
Abstract: In order to utilize solar power for the production of electricity and fuel on a massive scale, it will be necessary to develop solar photon conversion systems that have an appropriate combination of high efficiency (delivered watts/m2) and low capital cost ($/m2) to produce solar power that is competitive with coal. One potential, longterm approach to high efficiency is to utilize the unique properties of quantum dot nanostructures to control the relaxation dynamics of photogenerated carriers to produce either enhanced photocurrent through efficient photogenerated electronhole pair multiplication or enhanced photopotential through hot electron transport and transfer processes. To achieve these desirable effects it is necessary to understand and control the dynamics of hot electron and hole relaxation, cooling, charge transport, and interfacial charge transfer of the photogenerated carriers with femtosecond (fs) to ns time resolution. At NREL, we have been studying these fundamental dynamics in various bulk and nanoscale semiconductors (quantum dots (QDs), quantum rods/wires, and quantum wells) for many years using fs transient absorption, photoluminescence, and THz spectroscopy. Recently, we predicted that the generation of more than one electronhole pair (existing as excitons in QDs) per absorbed photon would be an efficient process in QDs . This prediction has been confirmed over the past several years in several classes of QDs. We have observed very efficient and ultrafast multiple exciton generation (MEG) from absorbed single high energy photons in Group IVVI and recently in Si QDs. Efficient MEG has the potential to greatly enhance the conversion efficiency of solar cells that incorporate QDs for both solar.  
Wilma K. Olson (Rutgers University)  Multiscale modeling of DNA 
Abstract: Encoded in the strings of DNA bases that make up the genomes of living species are codes that regulate, control, and describe all sorts of biological processes. The underpinnings of these codes lie in the base sequencedependent micromechanical properties of DNA, which determine the degree to which the long, threadlike molecule fluctuates and how it responds to the proteins that control its processing and govern its packaging. In order to understand the mechanisms by which DNA base sequence and tightly bound proteins control the biophysical properties of the long, threadlike molecule, we have developed a coarsegrained model, in which the DNA base pairs are treated as rigid bodies subject to realistic, knowledgebased energy constraints, and computational techniques to determine the minimumenergy configurations, intrinsic dynamics, and looping/cyclization propensities of these molecules. The presentation will highlight some of the unique, sequencedependent spatial information that has been gleaned from analyses of the highresolution structures of DNA and its complexes with other molecules and illustrate how this information can be used to gain new insights into sequencedependent DNA polymeric behavior.  
Shmuel Onn (TechnionIsrael Institute of Technology)  Nonlinear discrete optimization II 
Abstract: We develop an algorithmic theory of nonlinear optimization over sets of integer points presented by inequalities or by oracles. Using a combination of geometric and algebraic methods, involving zonotopes, Graver bases, multivariate polynomials and Frobenius numbers, we provide polynomialtime algorithms for broad classes of nonlinear combinatorial optimization problems and integer programs in variable dimension. I will overview this work, joint with many colleagues over the last few years, and discuss some of its many applications in statistics and operations research, including privacy in statistical databases, experimental design, nonlinear transportation, multicommodity flows, errorcorrecting codes, matroids and general independence systems.  
Ignacio Pagonabarraga Mora (University of Barcelona)  Soft potentials for coarse grained modeling 
Abstract: I will describe how to model the properties of nonideal fluids using effective, soft, many body potentials. Although they are not derived from a microscopic systematic procedure, it is possible to understand their properties from a systematic saddle point expansion. Such an approach makes it possible to derive their equilibrium thermodynamic and structural features, opening the possibility to relate the effective parameters characterizing the soft potentials with their collective properties. I will also describe how such many body potentials can be used to analyze the properties of complex fluids out of equilibrium.  
Stephen D Pankavich (Indiana University)  Allatom multiscale computational modeling of bionanosystem dynamics 
Abstract: The use of traditional techniques, such as Molecular Dynamics (MD), to model the longtime dynamics of bionanosystems (e.g., viruses, liposomes, or engineered nanocapsules for drug delivery) have proven infeasible, as the computational time required to obtain accurate results for the time scales of interest is on the order of many years. Using statistical mechanics, stochastic calculus, and techniques of multiscale analysis, we have recently designed (and are currently constructing) tools which greatly improve upon this problem by introducing and tracking slow variables that account for the largescale behavior of the given system. The new VirusX simulator decreases computational time to the order of hours, rendering such simulations feasible for the first time. This is joint work with Peter Ortoleva and the Center for Cell and Virus Theory at Indiana University.  
Cynthia A. Phillips (Sandia National Laboratories)  Parallelization issues for MINLP Part II 
Abstract: Sandia National Laboratories has invested considerable effort in massively parallel optimization tools. In this talk, we will summarize relevant experience from developing our parallel mixedinteger programming (MIP) solver PICO (Parallel Integer and Combinatorial Optimizer) and our parallel nonlinear solver GNLP. We will discuss parallel solution of mixedinteger nonlinear programs (MINLP). In particular, we will consider how the choice of parallel platform (tightlycoupled systems, cloud computing, grid computing, etc) can affect algorithmic decisions. We will highlight issues parallel solvers must face that serial solvers do not such as load balancing, ramp up, and termination and some issues that parallel solvers might do differently, such as decomposition. We expect some of our MIP/NLP experience to carry over, and some issues to be unique to, or uniquely difficult for, MINLP.  
Simon Poblete (Max Planck Institute for Polymer Research)  Adaptive resolution simulation of model mixtures 
Abstract: We have systematically developed a set of coarsegrained potentials able to describe a system of spherical monomers solved in tetrahedral molecules. The potentials are able to reproduce the basic structure and thermodynamics of the original mixture over a wide range of concentrations, and have been successfully tested in the Adaptive Resolution Scheme (AdResS), showing a symmetric behavior between the explicit and coarsegrained descriptions.  
Oleg Prezhdo (University of Washington)  Quantum dots and dyesensitized semiconductors for solar energy conversion: timedomain ab initio studies of the photoinduced dynamics 
Abstract: Harvesting and applications of solar energy requires an understanding of the dynamical response of novel materials on the nanometer scale. We have developed stateoftheart nonadiabatic molecular dynamics techniques and implemented them within timedependent density functional theory in order to model the ultrafast photoinduced processes in these materials at the atomistic level, and in real time. The talk will focus on the photoinitiated charge transfer at the moleculesemiconductor interfaces and multiple excitons which can be generated in semiconductor quantum dots in competition with various relaxation processes.  
Franz Rendl (Universität Klagenfurt)  Copositive programs and combinatorial optimization 
Abstract: It has recently been shown that linear programs over the cone of completely positive matrices give exact formulations for many NPhard combinatorial optimization problems. This motivates the investigation of solution methods for such problems. In this talk I will present a heuristic algorithm for this problem, whos main effort in each iteration consists in solving a convex quadratic problem in sign constrained variables. The algorithm will be applied to random copositive programs as well as to the copositive formulation of some NPhard graph optimization problems. (joint work with M. Bomze (Vienna) and F. Jarre (Duesseldorf))  
Christian Ringhofer (Arizona State University)  Computational aspects of solid state transport 
Abstract: This talk will discuss various issues and approaches in the numerical simulation of carrier transport in solid state materials, relevant to the modeling of optical generation / recombination. We will discuss aspects of deterministic and Monte Carlo methods for the solid state Boltzmann transport equation as well as the inclusion of quantum effects in particle based transport simulators.  
Mark O. Robbins (Johns Hopkins University)  Mapping particle based simulations to mesoscopic models 
Abstract: No Abstract  
Victor Rühle (Max Planck Institute for Polymer Research)  Charge transport in polypyrrole: the role of morphology 
Abstract: A combination of methods is used to study charge transport in polypyrrole melts. First, the OPLS atomistic force field is refined using firstprinciples calculations. Amorphous and partially ordered melts are then generated with the help of this forcefield. Finally, the charge mobility is calculated within the temperature activated hopping picture for charge transport [1]. [1] J. Kirkpatrick, V. Marcon, J. Nelson, K. Kremer, D. Andrienko, Phys. Rev. Lett. 98, 227402 (2007)  
Sebastian Sager (RuprechtKarlsUniversität Heidelberg)  Direct numerical methods for mixedinteger optimal control problems 
Abstract: Optimal control problems involving timedependent decisions from a finite set have gained much interest lately, as they occur in practical applications with a high potential for optimization. Typical examples are the choice of gears in transport or separation processes involving valves to switch inflow/outflow locations between trays or columns. We present relaxation and convexification based rounding strategies for direct methods of optimal control such that the resulting trajectory fulfills constraints and reaches the objective function value of any (and in particular the optimal) relaxed solution up to a certain tolerance. We show that this tolerance depends on the control discretization grid, in other words, that the rounded solution will be arbitrarily close to the relaxed one, if only the underlying grid is chosen fine enough. This is even true for a finite number of switches, and holds for the linear as well as for the nonlinear case, involving path and control constraints. Examples will be supplied to illustrate the procedure.  
Annick Sartenaer (Facultés Universitaires Notre Dame de la Paix (Namur))  A branchandrefine method for nonconvex mixed integer optimization 
Abstract: Joint work with Sven Leyffer (Argonne National Laboratory) and Emilie Wanufelle (University of Namur). Motivated by problems related to power systems analysis which give rise to nonconvex mixed integer nonlinear programming (MINLP) problems, we propose a global optimization method based on ideas and techniques that can be easily extended to handle a large class of nonconvex MINLPs. Our method decomposes the nonlinear functions appearing in the problem to solve into one and twodimensional components for which piecewise linear envelopes are constructed using ideas similar to special ordered sets. The resulting relaxations are then successively refined by branching on integer or continuous variables. We prove convergence to a global optimum within a desired accuracy under mild assumptions and present some preliminary numerical experience.  
Anureet Saxena (Axioma Inc.)  Convex relaxations of nonconvex MIQCP 
Abstract: Joint work with Pierre Bonami and Jon Lee. This talk addresses the problem of generating strong convex relaxations of Mixed Integer Quadratically Constrained Programming (MIQCP) problems. MIQCP problems are very difficult because they combine two kinds of nonconvexities: integer variables and nonconvex quadratic constraints. To produce strong relaxations of MIQCP problems, we use techniques from disjunctive programming and the liftandproject methodology. In particular, we propose new methods for generating valid inequalities by using the equation Y = x x^{T}. We use the concave constraint $0 succcurlyeq Y  x x^{T} $ to derive disjunctions of two types. The first ones are directly derived from the eigenvectors of the matrix Y  x x^{T} with positive eigenvalues, the second type of disjunctions are obtained by combining several eigenvectors in order to minimize the width of the disjunction. We also use the convex SDP constraint Y  x x^{T} succcurlyeq 0 to derive convex quadratic cuts, and we combine both approaches in a cutting plane algorithm. We present computational results to illustrate our findings.  
Anureet Saxena (Axioma Inc.)  Convex relaxations of nonconvex MIQCP 
Abstract: same abstract as the 11/18 talk  
Christof Schütte (Freie Universität Berlin)  Understanding effective molecular dynamics on timescales beyond possible simulation timescales 
Abstract: No Abstract  
Tsvetanka Sendova (University of Minnesota)  A theory of fracture based upon extension of continuum mechanics to the nanoscale 
Abstract: I will present the analysis of several fracture models based on a new approach to modeling brittle fracture. Integral transform methods are used to reduce the problem to a Cauchy singular, linear integrodifferential equation. We show that ascribing constant surface tension to the fracture surfaces and using the appropriate crack surface boundary condition, given by the jump momentum balance, leads to a sharp crack opening profile at the crack tip, in contrast to the classical theory of brittle fracture. However, such a model still predicts singular crack tip stress. For this reason we study a modified model, where the surface excess property is responsive to the curvature of the fracture surfaces. We show that curvaturedependent surface tension, together with boundary conditions in the form of the jump momentum balance, leads to bounded stresses and a cusplike opening profile at the crack tip. Finally, I will discuss two possible fracture criteria, in the context of the new theory. The first one is an energy based fracture criterion. Due to the fact that the proposed modeling approach allows us to fully resolve the stress in a neighborhood of the crack tip, without the customary singularity, a second fracture criterion, based on crack tip stress, is possible.  
Uday V. Shanbhag (University of Illinois at UrbanaChampaign)  A local relaxation approach for the siting of electrical substations 
Abstract: Joint work with Walter Murray (Stanford University). The siting and sizing of electrical substations on a rectangular electrical grid can be formulated as an integer programming problem with a quadratic objective and linear constraints. We propose a novel approach that is based on solving a sequence of local relaxations of the problem for a given number of substations. Two methods are discussed for determining a new location from the solution of the relaxed problem. Each leads to a sequence of strictly improving feasible integer solutions. The number of substations is then modified to seek a further reduction in cost. Lower bounds for the solution are also provided by solving a sequence of mixedinteger linear programs. Results are provided for a variety of uniform and Gaussian load distributions as well as some real examples from an electric utility. The results of GAMS/DICOPT, GAMS/SBB, GAMS/BARON and CPLEX applied to these problems are also reported. Our algorithm shows slow growth in computational effort with the number of integer variables.  
Lyubima B. Simeonova (University of Utah)  Spatial bounds on the effective complex permittivity for timeharmonic waves in random media 
Abstract: When we consider wave propagation in random media in the case when the wave length is finite, scattering effects must be accounted for and the effective dielectric coefficient is no longer a constant, but a spatially dependent function. We obtain a bound on the spatial variations of the effective permittivity that depends on the maximum volume of the inhomogeneities and the contrast of the medium. A related optimization problem of maximizing the spatial average of the effective dielectric coefficient with respect to the spatial probability density function is presented. The dependence of the effective dielectric coefficient on the contrast of the medium is also investigated and an approximation formula is derived.  
Florence Tama (University of Arizona)  Unveiling conformational changes of biological molecules using multiscale modeling and multiresolution experiments 
Abstract: Multipronged approaches have recently gained interest for tackling structural problems related to large biological complexes. Structural dynamical information is often obtained by lowresolution experimental techniques, such as Cryo Electron Microscopy (cryoEM), Small Angle Xray Scattering (SAXS) and Fluorescence Resonance Energy Transfer (FRET). Each of these techniques offers different advantages and meet with different pitfalls, artifacts and limitations. Therefore a more accurate description could be obtained if all pieces of experimental data were taken together to annotate conformational states. To achieve this goal we will present our current developments of multiresolution/multiscale computational tools to interpret conformational changes of biological molecules based on cryoEM, SAXS or distance constraints. Normal Mode Analysis or Molecular Dynamics simulations are used to deform, in a physical manner, Xray structures to fit lowresolution data. Using simulated data, we will show that such approaches are successful to predict structures in the range of 2~3 Å resolution.  
Tamás Terlaky (Lehigh University)  Some challenging mixed integer nonlinear optimization problems 
Abstract: Nonlinear mixed integer optimization has numerous applications in engineering practice. We present two classes of MINLP problems that arise in engineering practice, but their solution to proven optimality in size relevant for practice is beyond the capacity of available MINLP solvers. Both of the following problem classes offer the possibility to generate test problem suites with increasing problem size. The first problem class is the optimization of the reloading of nuclear reactor core, where the physics of the problem is governed by PDE's, whose discretization combined with the reloading (assignment constraints) provide a large family of large scale MINP problems. The second class of problems arise from flood control, where safe dike heights need to be built at minimal cost while considering the expected risk of flooding.  
Alex Travesset (Iowa State University)  General purpose molecular dynamics on graphic processing units (GPUs) 
Abstract: Molecular Dynamics (MD) on Graphic Processing Units (GPUs) provide spectacular advantages: an unexpensive GPU (less than 500$) provides the equivalent computer power of a 44 core cluster. This poster will introduce HOOMD, our new General purpose MD code, as well as describe the challenges involved in GPU programming. It will also show the very easy to use scripting system developed directed to the end user, so that it can make full use of HOOMD without having to learn about GPU programming. As it will become clear in the poster, HOOMD is particularly suited for coarsegrained MD.  
Sergei Tretiak (Los Alamos National Laboratory)  Functionalized quantum dots and conjugated polymers for light harvesting applications: Theoretical insights 
Abstract: Using density functional theory (DFT) and timedependent DFT quantumchemical methodologies, we investigate interplay of electronic properties and conformational dynamics in several optically active materials. In quantum dots we explore the role of surface ligands on the electronic structure and observe strong surfaceligand interactions leading to formation of hybridized states and polarization effects. This opens new relaxation channels for high energy photoexcitations. Computations of Ru(II)bipyridine attached to the semiconductor quantum dot systems demonstrate possibility of charge separation and energy transfer processes in the complex. In the amorphous clusters of conjugated polymers, we find that electron trap states are induced primarily by intramolecular configuration disorder, while the hole trap states are generated primarily from intermolecular electronic interactions. All these phenomena govern experimentally observed photoinduced dynamics and define technologically important properties of materials suitable for solar energy conversion.  
Erkan Tüzel (University of Minnesota)  Mesoscopic model for the fluctuating hydrodynamics of binary and ternary mixtures 
Abstract: A recently introduced particlebased model for fluid dynamics with continuous velocities is generalized to model immiscible binary mixtures. Excluded volume interactions between the two components are modeled by stochastic multiparticle collisions which depend on the local velocities and densities. Momentum and energy are conserved locally, and entropically driven phase separation occurs for high collision rates. An explicit expression for the equation of state is derived, and the concentration dependence of the bulk free energy is shown to be the same as that of the WidomRowlinson model. Analytic results for the phase diagram are in excellent agreement with simulation data. Results for the line tension obtained from the analysis of the capillary wave spectrum of a droplet agree with measurements based on the Laplace's equation. The dispersion relation for the capillary waves is derived and compared with the numerical measurements of the time correlations of the radial fluctuations in the damped and overdamped limits. The introduction of "amphiphilic" dimers makes it possible to model the phase behavior of ternary surfactant mixtures.  
Eric VandenEijnden (New York University)  A general strategy for the design of seamless multiscale methods 
Abstract: I will present a new general framework for designing multiscale methods. Compared with previous work such as Brandt’s systematic upscaling, the heterogeneous multiscale method and the “equationfree” approach, this new framework has the distinct feature that it does not require reinitializing the microscale model at each macro time step or each macro iteration step. In the new strategy, the macro and micromodels evolve simultaneously using diﬀerent time steps (and therefore diﬀerent clocks), and they exchange data at every step. The micromodel uses its own appropriate time step. The macromodel runs at a slower pace than required by accuracy and stability considerations for the macroscale dynamics, in order for the micromodel to relax. I will discuss applications of the new seamless approach to a toy system used in climatic studies, to the modeling of complex fluids, and to free energy calculations in molecular dynamics. This is joint work with Weinan E and Weiqing Ren with applications performed in collaboration with Ibrahim Fatkullin and Luca Maragliano.  
Stefan Vigerske (HumboldtUniversität)  Solving nonconvex MINLP by quadratic approximation 
Abstract: We present the extended Branch and Cut algorithm implemented in the software package LaGO for the solution of blockseparable nonconvex mixedinteger nonlinear programs. The algorithm reformulates every function into a blockseparable form and computes convex underestimators for each term separately. For that purpose, nonquadratic functions are first replaced by quadratic underestimators using a powerful heuristic. Nonconvex quadratic functions are then replaced by exakt convex underestimators. Finally, a linear outer approximation is constructed by linearization of the convex relaxation and the generation of mixedinteger rounding cuts and linearized interval gradient cuts. The efficiency of the method is improved by the application of a simple constraint propagation technique based on interval arithmetic.  
Zhongming Wang (University of California, San Diego)  A bloch band base level set method in the semiclassical limit of the Schroedinger Equation 
Abstract: It is now known that one can use level set description to accurately capture multiphases in computation of high frequency waves. In this paper, we develop a Bloch band based level set method for computing the semiclassical limit of Schrdinger equations in periodic media. For the underlying equation subject to a highly oscillatory initial data a hybrid of the WKB approximation and homogenization leads to the Bloch eigenvalue problem and an associated HamiltonJacobi system for the phase, with Hamiltonian being the Bloch eigenvalues. We evolve a level set description to capture multivalued solutions to the band WKB system, and then evaluate total position density over a sample set of bands. A superposition of band densities is established over all bands and solution branches when away from caustic points. Numerical results with different number of bands are provided to demonstrate the good quality of the method.  
Henry A. Warchall (National Science Foundation)  CHEDMRDMS solar energy initiative 
Abstract: No Abstract  
Robert Weismantel (OttovonGuerickeUniversität Magdeburg)  Nonlinear discrete optimization I 
Abstract: This talk is concerned with optimizing nonlinear functions over the lattice points in a polyhedral set. We present three families of polynomial time algorithms for special cases of the general problem. Each such algorithm makes use of combinatorial, geometric or algebraic properties of the underlying problem. The first problem deals with optimizing nonlinear functions over a matroid. (Joint work with Jon Lee and Shmuel Onn). The second class of problems concerns convex nfold integer minimization problems. (Joint work with Raymond Hemmecke and Shmuel Onn). Our last family of problems is to maximize polynomials over the integer points in a polytope when the dimension is fixed. Under mild assumptions we present an FPTAS for performing this task. (Joint work with Jesus De Loera, Matthias Koeppe and Raymond Hemmecke).  
Tapio Westerlund (Åbo Akademi (FinlandSwedish University of Åbo))  Global optimization of MINLP problems containing signomial functions 
Abstract: Joint work with Andreas Lundell, Process Design and Systems Engineering, Åbo Akademi University Biskopsgatan 8, FIN20500 Turku, Finland. Keywords: Transformation techniques; mixed integer nonlinear programming; signomial functions; global optimization. Abstract: In this presentation some transformation techniques are discussed. With the given techniques a class of nonconvex MINLP problems, including signomial functions, can be solved to global optimality. The transformation techniques are based on single variable power and exponential transformations and the signomial functions can be converted into convex form, by the transformations. In addition, the original nonconvex problem can be relaxed into convex form, if the transformations have certain properties and the inverse transformations are approximated by piecewise linear functions. The transformations are not unique and there exists degrees of freedom in selecting them. For determining an "optimal" set of transformations a mixed integer linear programming (MILP) problem can be formulated. The solution of the MILP problem can be used separately but acts, in our case, as a preprocessing step in the global optimization framework. Certain properties of the transformations can be emphasized in the initial MILP preprocessing step. For example, the total number of transformations needed can be minimized. The principles behind the transformation techniques are given and some numerical examples are used to illustrate the given techniques.  
Angelika Wiegele (Universität Klagenfurt)  Exact algorithms for the quadratic linear ordering problem 
Abstract: The quadratic linear ordering problem naturally generalizes various optimization problems, such as bipartite crossing minimization or the betweenness problem, which includes linear arrangement. These problems have important applications in, e.g., automatic graph drawing and computational biology. We present a new polyhedral approach to the quadratic linear ordering problem that is based on a linearization of the quadratic objective function. Our main result is a reformulation of the 3dicycle inequalities using quadratic terms, the resulting constraints are shown to be faceinducing for the polytope corresponding to the unconstrained quadratic problem. We exploit this result both within a branchandcut algorithm and within an SDPbased branchandbound algorithm. Experimental results for bipartite crossing minimization show that this approach clearly outperforms other methods. (Joint work with C. Buchheim and L. Zheng.)  
Xiaoyang Zhu (University of Minnesota)  Exciton dissociation in solar cells 
Abstract: Excitons are bound electronhole pairs, i.e., atomicH like Bosonic quasiparticles, that determine many optical and optoelectronic properties of solid materials. Exciton formation and dissociation play decisive roles in next generation solar cells. In a conventional pn junction solar cell, the builtin potential separates the photoexcited electron and hole. In contrast, separating the electron and the hole in an excitonic solar cell requires an energetic driving force at a donor/acceptor (D/A) materials interface. Here, photon absorption creates a localized Frenkel exciton or a delocalized MottWannier exciton in the donor material. Such an exciton migrates to the D/A interface and decays into a charge transfer (CT) exciton: the Coulombicallybound electron and hole are located in spatially separate regions across the interface. Subsequent dissociation of the CT exciton leads to charge carriers and photocurrent. In this talk, I will present our understanding on the exciton dissociation problem from recent experiments and discuss challenges in theoretical/computation treatment of this problem. These challenges arise because one must simultaneous take into account translational symmetry of the donor and acceptor (when the donor and/or acceptor are crystalline materials) and the spatial correlation of the eh pair. 
Cameron F. Abrams  Drexel University  11/2/2008  11/7/2008 
Rigoberto Advincula  University of Houston  10/31/2008  11/2/2008 
Alina Alexeenko  Purdue University  10/31/2008  11/2/2008 
Denis Andrienko  MaxPlanck Institut für Polymerforschung  11/1/2008  11/9/2008 
Kurt M. Anstreicher  University of Iowa  11/16/2008  11/21/2008 
Donald G. Aronson  University of Minnesota  9/1/2002  8/31/2009 
Alán AspuruGuzik  Harvard University  10/31/2008  11/2/2008 
Paul J. Atzberger  University of California, Santa Barbara  11/2/2008  11/7/2008 
Eray S. Aydil  University of Minnesota  11/1/2008  11/1/2008 
Gregory L Baker  Michigan State University  10/31/2008  11/2/2008 
Amartya Sankar Banerjee  University of Minnesota  11/2/2008  11/2/2008 
Gang Bao  Michigan State University  10/31/2008  11/2/2008 
Pietro Belotti  Lehigh University  11/16/2008  11/19/2008 
Hande Yurttan Benson  Drexel University  11/16/2008  11/21/2008 
Dimitris Bertsimas  Massachusetts Institute of Technology  11/18/2008  11/21/2008 
Lorenz T. Biegler  Carnegie Mellon University  11/20/2008  11/21/2008 
Christian Bliek  ILOG Corporation  11/15/2008  11/21/2008 
Marian Bocea  North Dakota State University  11/2/2008  11/8/2008 
Pierre Bonami  Centre National de la Recherche Scientifique (CNRS)  11/15/2008  11/22/2008 
Nawaf BouRabee  California Institute of Technology  11/2/2008  11/7/2008 
Bastiaan J. Braams  Emory University  9/28/2008  11/8/2008 
Andrea Braides  Seconda Università di Roma "Tor Vergata"  11/1/2008  11/7/2008 
James Joseph Brannick  Pennsylvania State University  10/30/2008  11/2/2008 
Frank L. H. Brown  University of California, Santa Barbara  11/2/2008  11/7/2008 
Peter Brune  University of Chicago  9/8/2008  6/30/2009 
Samuel Burer  University of Iowa  11/18/2008  11/21/2008 
Wei Cai  University of North Carolina  Charlotte  10/31/2008  11/2/2008 
MariaCarme T. Calderer  University of Minnesota  9/1/2008  6/30/2009 
Hannah Callender  University of Minnesota  9/1/2007  8/31/2009 
Roberto Cammi  Università di Parma  11/14/2008  12/20/2008 
Stephen Campbell  University of Minnesota  11/1/2008  11/1/2008 
Eric Cances  CERMICS  9/1/2008  12/23/2008 
Xianjin Chen  University of Minnesota  9/1/2008  8/31/2010 
Daniel M. Chipman  University of Notre Dame  9/14/2008  12/13/2008 
Marco Cicalese  Università di Napoli "Federico II"  11/1/2008  11/7/2008 
Bernardo Cockburn  University of Minnesota  11/1/2008  11/1/2008 
Ludovica Cecilia CottaRamusino  University of Minnesota  10/1/2007  12/12/2008 
Olivier Coulaud  Institut National de Recherche en Informatique Automatique (INRIA)  11/1/2008  11/7/2008 
Claudia D'Ambrosio  Università di Bologna  11/15/2008  11/22/2008 
Michel Jacques Daydé  Institut National Polytechnique de Toulouse  11/15/2008  11/21/2008 
Rafael DelgadoBuscalioni  Autonomous University of Madrid  11/1/2008  11/8/2008 
Luigi Delle Site  MaxPlanck Institut für Polymerforschung  11/1/2008  11/8/2008 
Jesus Antonio De Loera  University of California, Davis  11/16/2008  11/20/2008 
Jeffrey Derby  University of Minnesota  11/1/2008  11/1/2008 
Markus Deserno  Carnegie Mellon University  11/2/2008  11/7/2008 
David C. Dobson  University of Utah  10/31/2008  11/2/2008 
Belma Dogdas  Merck & Co., Inc.  11/13/2008  11/15/2008 
Masao Doi  University of Tokyo  11/2/2008  11/8/2008 
Dan Dougherty  North Carolina State University  10/31/2008  11/2/2008 
Sarah Drewes  TU Darmstadt  11/15/2008  11/21/2008 
Qiang Du  Pennsylvania State University  10/31/2008  11/5/2008 
Olivier Dubois  University of Minnesota  9/3/2007  8/31/2009 
Burkhard Dünweg  MaxPlanck Institut für Polymerforschung  11/1/2008  11/8/2008 
Phillip Duxbury  Michigan State University  10/31/2008  11/2/2008 
Weinan E  Princeton University  10/31/2008  11/6/2008 
Bob Eisenberg  Rush University Medical Center  11/1/2008  11/8/2008 
Bjorn Engquist  University of Texas  11/6/2008  11/8/2008 
Maria Esteban  Université de Paris IX (ParisDauphine)  9/27/2008  11/15/2008 
James W. Evans  Iowa State University  11/2/2008  11/5/2008 
Roland Faller  University of California, Davis  11/2/2008  11/6/2008 
Heather Lyn Finotti  University of Tennessee  10/31/2008  11/2/2008 
Daniel Flath  Macalester College  8/27/2008  12/20/2008 
Stephen Foster  Mississippi State University  10/31/2008  11/2/2008 
Christopher Fraser  University of Chicago  8/27/2008  6/30/2009 
Gero Friesecke  Technical University of Munich  11/2/2008  11/7/2008 
Dominik Fritz  Max Planck Institute for Polymer Research  11/1/2008  11/9/2008 
Kevin Furman  Exxon Research and Engineering Company  11/19/2008  11/22/2008 
Irene M. Gamba  University of Texas  10/31/2008  11/2/2008 
Weiguo Gao  Fudan University  9/27/2008  12/13/2008 
Carlos J. GarciaCervera  University of California, Santa Barbara  9/2/2008  12/12/2008 
David M. Gay  Sandia National Laboratories  11/16/2008  11/21/2008 
Johannes Giannoulis  Technical University of Munich  11/2/2008  11/9/2008 
Philip E. Gill  University of California, San Diego  11/16/2008  11/19/2008 
Guillermo Hugo Goldsztein  Georgia Institute of Technology  10/31/2008  11/2/2008 
Jay Gopalakrishnan  University of Florida  9/1/2008  2/28/2009 
Ignacio Grossmann  Carnegie Mellon University  11/20/2008  11/21/2008 
Oktay Gunluk  IBM  11/16/2008  11/21/2008 
Gloria Haro Ortega  Universitat Politecnica de Catalunya  10/25/2008  11/1/2008 
William E. Hart  Sandia National Laboratories  11/16/2008  11/21/2008 
Carsten Hartmann  Freie Universität Berlin  11/2/2008  11/7/2008 
Timothy F. Havel  Massachusetts Institute of Technology  10/31/2008  12/12/2008 
David Haws  University of California, Davis  11/16/2008  11/21/2008 
Teresa HeadGordon  University of California, Berkeley  11/2/2008  11/7/2008 
Christoph Helmberg  Technische Universität ChemnitzZwickau  11/15/2008  11/21/2008 
William Henry  Mississippi State University  10/31/2008  11/2/2008 
Mark S. Herman  University of Minnesota  9/1/2008  8/31/2010 
Jan S. Hesthaven  Brown University  10/31/2008  11/2/2008 
Peter Hinow  University of Minnesota  9/1/2007  8/31/2009 
Russell J. Holmes  University of Minnesota  11/1/2008  11/1/2008 
Yunkyong Hyon  University of Minnesota  9/1/2008  8/31/2010 
Mark Iwen  University of Minnesota  9/1/2008  8/31/2010 
Alexander Izzo  Bowling Green State University  9/1/2008  6/30/2009 
Richard D. James  University of Minnesota  11/1/2008  11/3/2008 
Richard D. James  University of Minnesota  11/2/2008  11/7/2008 
Samson A. Jenekhe  University of Washington  10/31/2008  11/2/2008 
Robert L. Jernigan  Iowa State University  11/5/2008  11/8/2008 
Srividhya Jeyaraman  University of Minnesota  9/1/2008  8/31/2010 
Lijian Jiang  University of Minnesota  9/1/2008  8/31/2010 
Shi Jin  University of Wisconsin  10/31/2008  11/1/2008 
Sookyung Joo  University of California, Santa Barbara  11/1/2008  11/22/2008 
Terry Joyce  3M  11/1/2008  11/1/2008 
Christoph Junghans  MaxPlanck Institut für Polymerforschung  11/1/2008  11/9/2008 
Raymond Kapral  University of Toronto  11/2/2008  11/6/2008 
Andreas G. Karabis  PI Medical Ltd  11/15/2008  11/22/2008 
Mikko Karttunen  University of Western Ontario  11/2/2008  11/7/2008 
Markos A. Katsoulakis  University of Massachusetts  10/31/2008  11/2/2008 
Toshihiro Kawakatsu  Tohoku University  11/2/2008  11/7/2008 
Markus Keel  University of Minnesota  7/21/2008  6/30/2009 
Mustafa Rasim Kilinc  University of Wisconsin  11/16/2008  11/21/2008 
Yongho Kim  University of Minnesota  11/1/2008  11/1/2008 
Erica Zimmer Klampfl  Ford  11/17/2008  11/21/2008 
William S. Klug  University of California, Los Angeles  11/2/2008  11/7/2008 
Matthias Koeppe  University of California, Davis  11/16/2008  11/21/2008 
Robert V. Kohn  New York University  10/31/2008  11/13/2008 
Kurt Kremer  MaxPlanck Institut für Polymerforschung  11/2/2008  11/8/2008 
Anna Krylov  University of Southern California  9/25/2008  12/25/2008 
Monica H. Lamm  Iowa State University  11/2/2008  11/7/2008 
Yueheng Lan  University of California, Santa Barbara  11/2/2008  11/8/2008 
Juan Latorre  Freie Universität Berlin  11/2/2008  11/7/2008 
Claude Le Bris  CERMICS  9/11/2008  5/30/2009 
ChiunChang Lee  National Taiwan University  8/26/2008  7/31/2009 
Hijin Lee  Korea Advanced Institute of Science and Technology (KAIST)  11/1/2008  11/1/2008 
Hijin Lee  Korea Advanced Institute of Science and Technology (KAIST)  11/3/2008  11/7/2008 
Jon Lee  IBM  11/16/2008  11/22/2008 
Long Lee  University of Wyoming  10/31/2008  11/2/2008 
Frédéric Legoll  École Nationale des PontsetChaussées  11/1/2008  11/12/2008 
Thomas Lehmann  Universität Bayreuth  11/15/2008  11/22/2008 
Sven Leyffer  Argonne National Laboratory  11/16/2008  11/21/2008 
Bo Li  University of California, San Diego  11/3/2008  11/6/2008 
Jichun Li  University of Nevada  10/31/2008  11/2/2008 
Tong Li  University of Iowa  11/2/2008  12/10/2008 
Yongfeng Li  University of Minnesota  9/1/2008  8/31/2010 
Leo Liberti  École Polytechnique  11/15/2008  11/22/2008 
TaiChia Lin  National Taiwan University  8/23/2008  7/31/2009 
Jeff Linderoth  University of Wisconsin  11/16/2008  11/21/2008 
Chun Liu  University of Minnesota  9/1/2008  8/31/2010 
Di Liu  Michigan State University  10/31/2008  11/2/2008 
Hailiang Liu  Iowa State University  11/4/2008  11/7/2008 
JianGuo Liu  University of Maryland  10/31/2008  11/4/2008 
Andrea Lodi  Università di Bologna  11/16/2008  11/18/2008 
Kevin Long  Texas Tech University  10/31/2008  11/2/2008 
Gang Lu  California State University  10/31/2008  11/2/2008 
James Luedtke  University of Wisconsin  11/17/2008  11/21/2008 
Mitchell Luskin  University of Minnesota  9/1/2008  6/30/2009 
Julien Mairal  INRIA  10/26/2008  11/2/2008 
Dionisios Margetis  University of Maryland  11/3/2008  11/7/2008 
Francois Margot  Carnegie Mellon University  11/16/2008  11/21/2008 
Susan Margulies  Rice University  11/17/2008  11/22/2008 
Alex Marker  Schott North America, Inc.  10/31/2008  11/2/2008 
Vasileios Maroulas  University of Minnesota  9/1/2008  8/31/2010 
Jesús MartínVaquero  University of Salamanca  11/2/2008  11/7/2008 
Vlasis George Mavrantzas  University of Patras  11/2/2008  11/7/2008 
James McCusker  Michigan State University  10/31/2008  11/2/2008 
Andrew James Miller  Université de Bordeaux I  11/16/2008  11/23/2008 
Kien Ming Ng  National University of Singapore  11/16/2008  11/22/2008 
John E. Mitchell  Rensselaer Polytechnic Institute  11/16/2008  11/21/2008 
Hans Mittelmann  Arizona State University  11/16/2008  11/19/2008 
Peter Monk  University of Delaware  10/31/2008  11/1/2008 
Susanna Monti  Consiglio Nazionale delle Ricerche (CNR)  11/1/2008  11/9/2008 
Marcus Müller  GeorgAugustUniversität zu Göttingen  11/1/2008  11/6/2008 
Todd S. Munson  Argonne National Laboratory  11/16/2008  11/21/2008 
Mahdi Namazifar  University of Wisconsin  11/16/2008  11/21/2008 
Giacomo Nannicini  École Polytechnique  11/15/2008  11/22/2008 
Zuhair Nashed  University of Central Florida  10/31/2008  11/2/2008 
Olalla Nieto Faza  University of Minnesota  11/3/2008  11/7/2008 
Jorge Nocedal  Northwestern University  11/16/2008  11/21/2008 
William G. Noid  Pennsylvania State University  11/2/2008  11/6/2008 
David Norris  University of Minnesota  11/1/2008  11/1/2008 
Arthur J. Nozik  Department of Energy  10/31/2008  11/2/2008 
Sang Hyun Oh  University of Minnesota  11/1/2008  11/1/2008 
Isamu Ohnishi  Hiroshima University  11/1/2008  1/17/2009 
Wilma K. Olson  Rutgers University  11/3/2008  11/7/2008 
Shmuel Onn  TechnionIsrael Institute of Technology  11/16/2008  11/22/2008 
Daniel OseiKuffuor  University of Minnesota  11/2/2008  11/7/2008 
Ignacio Pagonabarraga Mora  University of Barcelona  11/2/2008  11/7/2008 
Richa Pandey  University of Minnesota  11/1/2008  11/1/2008 
Stephen D Pankavich  Indiana University  10/31/2008  11/7/2008 
Pablo A. Parrilo  Massachusetts Institute of Technology  11/16/2008  11/22/2008 
Jaroslav Pekar  Honeywell  11/15/2008  11/21/2008 
Jiming Peng  University of Illinois at UrbanaChampaign  11/16/2008  11/22/2008 
Cynthia A. Phillips  Sandia National Laboratories  11/16/2008  11/21/2008 
Simon Poblete  Max Planck Institute for Polymer Research  11/1/2008  11/9/2008 
Cristina Popovici  North Dakota State University  11/2/2008  11/8/2008 
Matej Praprotnik  Max Planck Institute for Polymer Research  10/8/2008  11/8/2008 
Oleg Prezhdo  University of Washington  10/31/2008  11/2/2008 
Emil Prodan  Yeshiva University  10/31/2008  11/2/2008 
Keith Promislow  Michigan State University  10/31/2008  11/6/2008 
Kashif Rashid  Schlumberger Cambridge Research Laboratories  11/16/2008  11/21/2008 
Weiqing Ren  New York University  11/4/2008  11/7/2008 
Franz Rendl  Universität Klagenfurt  11/15/2008  11/21/2008 
Christian Ringhofer  Arizona State University  10/31/2008  11/2/2008 
Mark O. Robbins  Johns Hopkins University  11/2/2008  11/6/2008 
Kees Roos  Technische Universiteit te Delft  11/17/2008  11/21/2008 
Victor Rühle  Max Planck Institute for Polymer Research  11/1/2008  11/9/2008 
Yousef Saad  University of Minnesota  11/3/2008  11/7/2008 
Sebastian Sager  RuprechtKarlsUniversität Heidelberg  11/16/2008  11/23/2008 
Fadil Santosa  University of Minnesota  7/1/2008  6/30/2010 
Annick Sartenaer  Facultés Universitaires Notre Dame de la Paix (Namur)  11/15/2008  11/21/2008 
Garikapati Narahari Sastry  Indian Institute of Chemical Technology  11/2/2008  11/7/2008 
Andreas Savin  Université de Paris VI (Pierre et Marie Curie)  10/8/2008  11/6/2008 
Anureet Saxena  Axioma Inc.  11/17/2008  11/19/2008 
Arnd Scheel  University of Minnesota  9/1/2008  6/30/2009 
Roman Schubert  University of Bristol  10/5/2008  11/8/2008 
Christof Schütte  Freie Universität Berlin  11/1/2008  11/5/2008 
Ridgway Scott  University of Chicago  9/1/2008  6/30/2009 
Tsvetanka Sendova  University of Minnesota  9/1/2008  8/31/2010 
Yuk Sham  University of Minnesota  9/1/2008  6/30/2009 
Uday V. Shanbhag  University of Illinois at UrbanaChampaign  11/16/2008  11/19/2008 
Stephen Shipman  Louisiana State University  10/31/2008  11/2/2008 
ChiWang Shu  Brown University  10/31/2008  11/2/2008 
Heinz Siedentop  LudwigMaximiliansUniversität München  9/22/2008  12/19/2008 
Lyubima B. Simeonova  University of Utah  11/2/2008  11/7/2008 
Donald H. Singley  3M  11/1/2008  11/1/2008 
Valery P. Smyshlyaev  University of Bath  11/3/2008  11/8/2008 
Andrew M. Stein  University of Minnesota  9/1/2007  8/31/2009 
John M. Stockie  Simon Fraser University  11/2/2008  11/7/2008 
Bo Su  Iowa State University  11/2/2008  11/7/2008 
Qiyu Sun  University of Central Florida  10/31/2008  11/2/2008 
Ellad B Tadmor  University of Minnesota  11/2/2008  11/7/2008 
Florence Tama  University of Arizona  11/5/2008  11/7/2008 
Molei Tao  California Institute of Technology  11/1/2008  11/8/2008 
P. Craig Taylor  Colorado School of Mines  10/31/2008  11/1/2008 
Tamás Terlaky  Lehigh University  11/16/2008  11/21/2008 
Brooke Timp  University of Minnesota  11/1/2008  11/1/2008 
William Tisdale  University of Minnesota  11/1/2008  11/1/2008 
Alex Travesset  Iowa State University  11/2/2008  11/7/2008 
Sergei Tretiak  Los Alamos National Laboratory  10/31/2008  11/1/2008 
Donald G. Truhlar  University of Minnesota  9/1/2008  6/30/2009 
Birkan Tunc  Istanbul Technical University  10/25/2008  11/1/2008 
Erkan Tüzel  University of Minnesota  9/1/2007  8/31/2009 
Steven M. Valone  Los Alamos National Laboratory  9/8/2008  11/30/2008 
Eric VandenEijnden  New York University  11/1/2008  11/7/2008 
Jon Van Laarhoven  University of Iowa  11/16/2008  11/22/2008 
Mark van Schilfgaarde  Arizona State University  10/31/2008  11/2/2008 
Stefan Vigerske  HumboldtUniversität  11/15/2008  11/21/2008 
Tho T. Vu  TopVu Technology, Inc  11/1/2008  11/1/2008 
Bruce Wade  University of Wisconsin  11/2/2008  11/8/2008 
Andreas Waechter  IBM  11/16/2008  11/22/2008 
Brenton Walker  Laborartory For Telecommunications Sciences  10/26/2008  11/1/2008 
Richard A. Waltz  University of Southern California  11/16/2008  11/21/2008 
Hong Wang  University of South Carolina  10/31/2008  11/2/2008 
LinWang Wang  Lawrence Berkeley National Laboratory  10/31/2008  11/2/2008 
Qi Wang  University of South Carolina  10/31/2008  11/2/2008 
Zhian Wang  University of Minnesota  9/1/2007  8/31/2009 
Zhongming Wang  University of California, San Diego  11/2/2008  11/8/2008 
Henry A. Warchall  National Science Foundation  10/31/2008  11/2/2008 
Robert Weismantel  OttovonGuerickeUniversität Magdeburg  11/16/2008  11/21/2008 
Tapio Westerlund  Åbo Akademi (FinlandSwedish University of Åbo)  11/15/2008  11/22/2008 
Angelika Wiegele  Universität Klagenfurt  11/15/2008  11/21/2008 
Colin Wolden  Colorado School of Mines  10/31/2008  11/2/2008 
Dexuan Xie  University of Wisconsin  9/4/2008  12/15/2008 
Wei Xiong  University of Minnesota  9/1/2008  8/31/2010 
Jue Yan  Iowa State University  10/31/2008  11/1/2008 
Chao Yang  Lawrence Berkeley National Laboratory  9/8/2008  11/8/2008 
Fei Yang  University of Minnesota  11/17/2008  11/21/2008 
Xingzhou Yang  Mississippi State University  10/31/2008  11/2/2008 
Aaron Nung Kwan Yip  Purdue University  11/1/2008  11/8/2008 
Haijun Yu  Purdue University  11/2/2008  11/8/2008 
Jin Yu  University of California, Berkeley  11/2/2008  11/7/2008 
Luping Yu  University of Chicago  10/31/2008  11/1/2008 
Trihua Yu  3M  11/1/2008  11/1/2008 
Hongchao Zhang  Louisiana State University  11/16/2008  11/22/2008 
Weigang Zhong  University of Minnesota  9/1/2008  8/31/2010 
Xiaoyang Zhu  University of Minnesota  11/1/2008  11/1/2008 
Yu Zhuang  Texas Tech University  10/30/2008  11/2/2008 