Web: http://www.ima.umn.edu | Email: ima-staff@ima.umn.edu | Telephone: (612) 624-6066 | Fax: (612) 626-7370
This month's talks available at http://www.ima.umn.edu/newsletters

IMA Newsletter #340

February 2005

2004-2005 Program

Mathematics of Materials and Macromolecules

See http://www.ima.umn.edu/matter for a full description of the 2004-2005 program on
Mathematics of Materials and Macromolecules: Multiple Scales, Disorder, and Singularities.

News and Notes

2005-2006 IMA New Directions program

The IMA New Directions program offers extraordinary opportunities for established mathematicians to branch into new directions and increase the impact of their research.

IMA 2005-2006 New Directions Visiting Professors will spend the academic year immersed in the thematic program at the IMA, enjoying an excellent research environment and stimulating scientific program with broad mathematical connections including harmonic analysis, partial differential equations, integral geometry, calculus of variations, probability theory, statistics, and learning theory. The New Directions program supplies 50% of faculty salary, up to $45,000 maximum, with the Visiting Professor's home institution providing a minimum of 50% of academic year salary and all benefits. The application deadline for a New Directions Visiting Professorship is March 1, 2005.

The 2005 IMA New Directions Short Course Quantum Computation will take place August 15-26, 2005. This intensive short course designed to efficiently provide mathematicians the basic knowledge prerequisite to undertake research in quantum computation. The principal instructors will be Peter Shor, Professor of Mathematics at MIT and Alexei Kitaev, Professor of Physics and Computer Science, Caltech. Participants will receive full travel and lodging support during the workshop. The application deadline for the short course is April 1, 2005.

IMA Events

IMA Workshop

Career Options for Women in Mathematical Sciences

February 4-5, 2005

Organizers: Natalia Alexandrov (NASA Langley Research Center), Kathryn E. Brenan (Aerospace Corporation), L. Pamela Cook (University of Delaware), Erica Zimmer Klampfl (Ford Motor Company), Suzanne Lenhart (University of Tennessee), Debra Lewis (University of Minnesota)

http://www.ima.umn.edu/cwims/

The workshop Career Options for Women in Mathematical Sciences aims to familiarize women in the mathematical sciences with professional opportunities in industry and government labs, and to suggest strategies for not merely surviving, but thriving. The workshop is geared primarily towards graduate students and PhDs in the early stages of their post-graduate careers, but should be valuable for researchers at all stages of professional development. Invited speakers, panelists and discussion leaders are women in research and management positions in industry and government labs, and women in academia with strong industrial ties.

IMA Tutorial

The Mathematics of Composite Materials

February 7-9, 2005

http://www.ima.umn.edu/matter/winter/t2.html

Composites play a vital role in industry, from carbon-fibre materials, to polycrystalline alloys with the crystal microstructure tailored to achieve desired design parameters, to rocket fuels of metallic particles in an oxidizing matrix, to porous materials for filtering and storage, to electro and magneto rheological fluids, to photonic and phononic band gap structures, and to novel nanostructured materials. Composites are also a source of fascinating mathematics in the quest to understand how features of the microstructure determine the overall macroscopic properties of a material. This tutorial/workshop includes a series of tutorials on problems of direct interest to industry, research reports and problem posing by industrial scientists, and break out discussion groups.

IMA Public Lecture

Dr. David Baraff

Math Behind the Curtains: Dynamic Simulation at Pixar Animation Studios

February 9, 2005

http://www.ima.umn.edu/public-lecture/2004-05/baraff/

Pixar's movies (Monsters, Inc., Finding Nemo, and The Incredibles) have relied heavily on a sophisticated mathematical technique called dynamic simulation to shape the final look and behavior of the movies' main characters. From the beginning, however, it has been set in stone that the use of dynamic simulation could not interfere in Pixar's traditional creative process. Senior animation scientist David Baraff gives a candid behind-the-scenes look at the core physical simulation technologies employed in Pixar's recent movies, describes the balancing of creative and technical needs due to simulation, and reveals the difficult effects that were easy, and the simple shots that were hard.
Schedule

Tuesday, February 1

11:15a-12:15pWave breaking in a class of nonlocal dispersive wave equationsHailiang Liu
Iowa State University
Lind Hall 409 PS

Wednesday, February 2

11:15a-12:15pSingular Solutions to a Regular ProblemBaisheng Yan
Michigan State University
Lind Hall 409 MS
3:35p-4:35pDivorcing pressure from viscosity in incompressible Navier-Stokes dynamicsRobert Pego
Carnegie Mellon University
Vincent Hall 301

Thursday, February 3

12:20p-1:20pDiffusion Tensor ImagingKelvin Lim
University of Minnesota
Lind Hall 409 iPAWS
3:30p-4:30pFifty Years after Fermi, Pasta, and Ulam: Nonlinear waves in Hamiltonian chains at low energyRobert Pego
Carnegie Mellon University
Vincent Hall 16

Friday, February 4

8:30a-12:30pNegotiation skills session (participation by invitation only)Barbara Butterfield
HUMANED
Jane W. Tucker
Duke University
EE/CS 3-180 SW2.4-5.05
11:15a-12:15pA multiscale model for the dynamics of solidsXiantao Li
University of Minnesota
Lind Hall 409 MS
12:30p-1:45pLunch break SW2.4-5.05
1:45p-2:00pOpening remarksEE/CS 3-180 SW2.4-5.05
2:00p-2:45pBuilding a career at the NSAMichelle Wagner
National Security Agency
EE/CS 3-180 SW2.4-5.05
2:45p-3:15pBecoming an applied mathematician - From mathematical logic to airplanesMiriam Lucian
Boeing Company
EE/CS 3-180 SW2.4-5.05
3:15p-3:30pCoffee breakEE/CS 3-176 SW2.4-5.05
3:30p-4:00pMathematical Perspectives on NASA ApplicationsNatalia Alexandrov
NASA Langley Research Center
EE/CS 3-180 SW2.4-5.05
4:00p-4:15pGroup photoLind Hall 400 SW2.4-5.05
4:15p-5:30pReception and poster sessionLind Hall 400 SW2.4-5.05
Scalable conceptual interfaces in hypreAllison Baker
Lawrence Livermore National Laboratories
Decoding Algebraic Geometric Codes over RingsKatherine Bartley
University of Nebraska-Lincoln
The Numerical Solution of Linear Quadratic Optimal Control Problems by Time-Domain DecompositionAgata Comas
Rice University
Graph-theoretic method for the discretization of gene expression measurementsElena Dimitrova
Virginia Tech
Uniform convergence of a multigrid energy-based quantization schemeMaria Emelianenko
Pennsylvania State University
Discrete network approximation for highly-packed composites with irregular geometry in three dimensions Yuliya Gorb
Pennsylvania State University
Multifidelity optimization using asynchronous parallel pattern search and space mappingGenetha Anne Gray
Sandia National Laboratories
New perspective for simulating incompressible fluid flows with free boundaryGiovanna Guidoboni
University of Houston
Rigorous numerical computations in complex dynamical systemsJennifer Suzanne Hruska
Indiana University
An Optimization Algorithm for the Identification of Biochemical Network ModelsMartha Paola Vera Licona
Virginia Tech
On efficient high-order schemes for acoustic waveform simulation Hyeona Lim
Mississippi State University
Numerical analysis of the Exponential Euler method and its suitability for dynamic clamp experimentsMaeve McCarthy
Murray State University
A convergence analysis of generalized iterative methods in finite-dimensional lattice-normed spacesElena Nagaeva
[None]
Evans function for periodic waves in infinite cylindrical domainMyunghyun Oh
Ohio State University
The effect of gravity modulation on the onset of filtrational convectionNatalya Popova
University of Illinois - Chicago
Stochastic modeling of macroevolutionLea Popovic
University of Minnesota
A story about YangiansNatalie Rojkovskaia
University of Wisconsin - Madison
A symbolic dynamical system for reconstructing repetitive DNA Suzanne Sindi
University of Maryland
A mathematical model for cell movement in tumor induced angiogenesisNicoleta Tarfulea
University of Minnesota
5:45p-8:55pDinner with working groups SW2.4-5.05

Saturday, February 5

9:00a-9:45aMath inside IBMBrenda Dietrich
IBM Corporation
EE/CS 3-180 SW2.4-5.05
9:45a-10:15aComplex fluid systems in nanotechnology, biology, and lifeLaura JD Frink
Sandia National Laboratories
EE/CS 3-180 SW2.4-5.05
10:15a-10:45aCoffee breakEE/CS 3-176 SW2.4-5.05
10:45a-11:15aRadar imagingMargaret Cheney
Rensselaer Polytechnic Institute
EE/CS 3-180 SW2.4-5.05
11:15a-11:45aMathematics of risk managementDiana Woodward
Societe Generale
Lind Hall 409 SW2.4-5.05
11:45a-12:15pThermoacoustic tomography - Inversion of a spherical radon transform with partial dataSarah K. Patch
General Electric
EE/CS 3-180 SW2.4-5.05
12:15p-1:30pLunch SW2.4-5.05
1:30p-2:00pWomen mathematicians: We can do more than teachErica Zimmer Klampfl
Ford Motor Company
EE/CS 3-180 SW2.4-5.05
2:00p-3:00pPanel discussionPam Binns
Honeywell
Kathryn E. Brenan
Aerospace Corporation
Yiju Chao
Morton Consulting Corporation
Suzanne Lenhart
University of Tennessee
Janet Pavelich
Lockheed Martin
Lalitha Venkataramanan
Schlumberger-Doll Research
EE/CS 3-180 SW2.4-5.05
3:00p-3:30pCoffee breakEE/CS 3-176 SW2.4-5.05
3:30p-5:00pWorking groupsEE/CS 3-180 SW2.4-5.05
5:15p-6:00pReports of working groups EE/CS 3-180 SW2.4-5.05
6:15p-7:45pDinner SW2.4-5.05
8:00p-8:55pMovie "To Dream Tomorrow"EE/CS 3-180 SW2.4-5.05

Monday, February 7

8:30a-9:15aCoffee and registrationEE/CS 3-176 T2.7-9.05
9:15a-9:30aWelcome and introductionDouglas N. Arnold
University of Minnesota
EE/CS 3-180 T2.7-9.05
9:30a-10:30aComposite properties and microstructure Robert P. Lipton
Louisiana State University
EE/CS 3-180 T2.7-9.05
10:30a-11:00aCoffee breakEE/CS 3-176 T2.7-9.05
11:00a-12:00pComposite properties and microstructure Robert P. Lipton
Louisiana State University
EE/CS 3-180 T2.7-9.05
12:00p-1:30pLunch break T2.7-9.05
1:30p-2:30pNanoparticle suspensions with giant electrorheological responsePing Sheng
Hong Kong University of Science & Technology
EE/CS 3-180 T2.7-9.05
2:30p-3:00pCoffee breakEE/CS 3-176 T2.7-9.05
3:00p-4:00pNanoparticle suspensions with giant electrorheological responsePing Sheng
Hong Kong University of Science & Technology
EE/CS 3-180 T2.7-9.05
4:15p-4:30pGroup photoLind Hall 400 T2.7-9.05
4:30p-6:00pIMA Tea and moreLind Hall 400 T2.7-9.05

Tuesday, February 8

9:00a-9:30aCoffeeEE/CS 3-176 T2.7-9.05
9:30a-10:30aModeling the pipeline of high performance, nano-composite materials and effective propertiesM. Gregory Forest
University of North Carolina
EE/CS 3-180 T2.7-9.05
10:30a-11:00aCoffee breakEE/CS 3-176 T2.7-9.05
11:00a-12:00pModeling the pipeline of high performance, nano-composite materials and effective properties M. Gregory Forest
University of North Carolina
EE/CS 3-180 T2.7-9.05
12:00p-1:30pLunch break T2.7-9.05
1:30p-4:00pIndustrial problems presentationsEE/CS 3-180 T2.7-9.05
Scaling and properties of microstructured compositesSuping Lyu
Medtronic, Inc.
Darrel Untereker
Medtronic, Inc.
Nonlinear FEM modeling of metal matrix composite laminatesJames Sorensen
3M

Wednesday, February 9

9:00a-9:30aCoffeeEE/CS 3-176 T2.7-9.05
9:30a-12:00pModerated break-out sessionsEE/CS 3-180 T2.7-9.05
12:00p-1:30pLunch break T2.7-9.05
1:30p-3:00pWrap-up and follow-up recommendationsEE/CS 3-180 T2.7-9.05
3:00p-3:15pClosing remarksEE/CS 3-180 T2.7-9.05
7:00p-8:00pMath Matters - IMA Public Lecture
Math Behind the Curtains: Dynamic Simulation at Pixar Animation Studios
David Baraff
Pixar Animation Studios
Amundson Hall B75 PUB2.9.05

Thursday, February 10

12:20p-12:45pSMARTPAPER: Reconstruction of Line Drawings by OptimizationAmit Shesh
University of Minnesota
Lind Hall 409 iPAWS
12:45p-1:10pFast Image and Video Colorization Using Chrominance BlendingLiron Yatziv
University of Minnesota
Lind Hall 409 MS

Friday, February 11

11:15a-12:15pThe Vortex State of MindJacob Rubinstein
Indiana University
Lind Hall 409 MS
1:25p-2:25pTBARandy Jacobus
ASA LLC
Vincent Hall 570 IPS

Monday, February 14

11:15a-12:15pTBAValery P. Smyshlyaev
University of Bath
Lind Hall 409 MS

Thursday, February 17

12:20p-1:10pPoint Cloud TopologyGeorge Kamberov
Stevens Institute of Technology
Lind Hall 409 iPAWS

Friday, February 18

1:25p-2:25pTBAJohn Anthony Dodson
American Express Financial Advisors
Vincent Hall 570 IPS

Thursday, February 24

12:20p-1:10pNoninvasive Two-dimensional Temperature Estimation Using Diagnostic UltrasoundEmad S. Ebbini
University of Minnesota
Lind Hall 409 iPAWS

Friday, February 25

Monday, February 28

11:15a-12:15pTBAShankar Venkataramani
University of Arizona
Lind Hall 409 MS
Abstracts
Natalia Alexandrov (NASA Langley Research Center) Mathematical Perspectives on NASA Applications
Abstract: NASA is an unending source of spectacularly interesting problems for an applied mathematician. Although it has traditionally been an "engineering shop", in recent years the growing complexity of goals and the ever increasing computational power clearly necessitate the development of sophisticated computational models and rigorous numerical procedures, thus providing an opportunity for a closer collaboration between NASA engineers, scientists and applied mathematicians. I will give an overview of some interesting problems in modeling and design, as well as some ideas of working for and with NASA.
Allison Baker (Lawrence Livermore National Laboratories) Scalable conceptual interfaces in hypre
Abstract: The hypre software library provides high performance preconditioners and solvers for massively parallel computers. For ease of use, hypre's conceptual interfaces allow users to describe a problem in a natural way, such as in terms of grids and stencils. In anticipation of machines with tens or hundreds of thousands of processors, we recently re-examined these interfaces and made substantial design changes to improve scalability. In this poster, we describe the challenges we faced and present solutions.
Katherine Bartley (University of Nebraska-Lincoln) Decoding Algebraic Geometric Codes over Rings
Abstract: Many techniques of algebraic geometry have been applied to study of linear codes over finite fields, beginning with the definition of algebraic geometry codes by Goppa in 1977. In 1996 Walker defined algebraic geometric codes over rings after it had been shown that certain nonlinear binary codes are nonlinear projections of liner codes over Z/4. Many algorithms have been developed for the efficient decoding of algebraic-geometric codes over fields. We will show that we can modify the 'Basic Algorithm' to decode algebraic geometric codes over rings with respect to the Hamming distance. We would also like to find a decoding algorithm that decodes algebraic geometric codes over rings with respect to the squared Euclidean distance.
Margaret Cheney (Rensselaer Polytechnic Institute) Radar imaging
Abstract: This talk will survey some of the mathematical ideas behind the formation of high-resolution images from radar data, and will outline some of the open problems in the field.
Agata Comas (Rice University) The Numerical Solution of Linear Quadratic Optimal Control Problems by Time-Domain Decomposition
Abstract: Optimal control problems governed by time--dependent partial differential equations (PDEs) lead to large-scale optimization problems. While a single PDE can be solved marching forward in time, the optimality system for time-dependent PDE constrained optimization problems introduces a strong coupling in time of the governing PDE, the so-called adjoint PDE, which has to be solved backward in time, and the gradient equation. This coupling in time introduces huge storage requirements for solution algorithms. We study a time-domain decomposition based method that addresses the problem of storage and additionally introduces parallelism into the optimization algorithm. The method reformulates the original problem as an equivalent optimization problem using ideas from multiple shooting methods for PDEs. For convex linear--quadratic problems, the optimality conditions of the reformulated problems lead to a linear system in state and adjoint variables at time--domain interfaces and in the original control variables. This linear system is solved using a preconditioned Krylov subspace method.
Brenda Dietrich (IBM Corporation) Math inside IBM
Abstract: In this talk I will discuss several IBM Research projects in which advanced mathematics is used to dramatically improve IBM products and processes. Examples include product design, manufacturing process design, and supply chain operations. I will also discuss ways in which our ability to deploy mathematics, by embedding the math in automated processes or tools, has dramatically improved in the past 20 years.
Elena Dimitrova (Virginia Tech) Graph-theoretic method for the discretization of gene expression measurements
Abstract: The poster introduces a method for the discretization of experimental data into a finite number of states. While it is of interest in various fields, this method is particularly useful in bioinformatics for reverse engineering of gene regulatory networks built from gene expression data. Many of these applications require discrete data, but gene expression measurements are continuous. Statistical methods for discretization are not applicable due to the prohibitive cost of obtaining sample sets of sufficient size. We have developed a new method of discretizing the variables of a network into the same optimal number of states while at the same time preserving maximum information. We employ graph-theoretic method to affect the discretization of gene expression measurements. Our C++ program takes as an input one or more time series of gene expression data and discretizes these values into a number of states that best fits the data. The method is being validated on a recently published computational algebra approach to the reverse engineering of gene regulatory networks by Laubenbacher and Stigler.
Emad S. Ebbini (University of Minnesota) Noninvasive Two-dimensional Temperature Estimation Using Diagnostic Ultrasound
Abstract: The talk will cover basic principles and reconstruction algorithms with examples from experimental image data from tissue and tissue-mimicking phantoms. This is part of our ongoing research on developing ultrasonic systems for noninvasive image-guided surgery.
Maria Emelianenko (Pennsylvania State University) Uniform convergence of a multigrid energy-based quantization scheme
Abstract: We propose a new multigrid quantization scheme in a nonlinear energy-based optimization setting. The problem of constructing an optimal vector quantizer based on the Centroidal Voronoi Tesselation is nonlinear in nature and hence cannot in general be analyzed using standard linear multigrid approach. We try to overcome this difficulty by essentially relying on the energy minimization. Since the energy functional is in general non-convex, a dynamic nonlinear preconditioner is proposed to relate our problem to a sequence of convex optimization problems. In the case of the one-dimensional problem, we have shown that for a large class of density functions, the nonlinear multigrid algorithm enjoys uniform convergence properties independent of k, the problem size, thus a significant speedup comparing to the traditional Lloyd-Max iteration is achieved. We show some results of numerical experiments and discuss analytical extensions of our theoretical framework to higher dimensions.
M. Gregory Forest (University of North Carolina) Modeling the pipeline of high performance, nano-composite materials and effective properties
Abstract: We focus these lectures on the class of nano-composites comprised of nematic polymers, either rod-like or platelet-like macromolecules, together with a matrix or solvent. These materials are designed for high performance, multifunctional properties, including mechanical, thermal, electric, piezoelectric, aging, and permeability. The ultimate goal is to prescribe performance features of materials under conditions they are likely to be exposed, and then to reverse engineer the pipeline by picking the composition and processing conditions which generate properties with those performance characteristics. These lectures will address two critical phases of this nano-composite materials pipeline. First, we model flow processing of nematic polymer films, providing information about anisotropy, dynamics, and heterogeneity of the molecular orientational distributions and associated stored elastic stresses. Second, we determine various effective property tensors of these materials based on the processing-induced orientational distribution data. Underlying these technological applications is a remarkable sensitivity of nematic polymer liquids to shear-dominated flow, which must be understood from rigorous multiscale, multiphysics theory, modeling and simulation in order to approach the ultimate goal stated above. This research is based on multiple collaborations and supported by various federal sponsors, to be highlighted during the lectures.
Laura JD Frink (Sandia National Laboratories) Complex fluid systems in nanotechnology, biology, and life
Abstract: Complex fluids are ubiquitous in nanoscale materials, at interfaces, and in biology. They are typically modeled with either molecular simulation or molecular theory approaches. Our research has emphasized implementation of large scale algorithms for density functional theory based approaches to these problems. In density functional theories a free energy functional is minimized to determine an optimal solution. It turns out that many women also find their lives to be complex fluid systems that require daily optimization around the constraints of the career, their home, and their families. This seminar will present briefly the content of one applied math career in the context of a national lab, and also discuss how the work-family balance can be achieved in this setting.
Yuliya Gorb (Pennsylvania State University) Discrete network approximation for highly-packed composites with irregular geometry in three dimensions
Abstract: In this poster, a discrete network approximation to the problem of the effective conductivity of a high contrast, densely packed composite in three dimensions is introduced. The inclusions are irregularly (randomly) distributed in a host medium. For this class of arrays of inclusions a discrete network approximation for effective conductivity is derived and a priori error estimates are obtained. A variational duality approach is used to provide a rigorous mathematical justification for the approximation and its error estimate.
Genetha Anne Gray (Sandia National Laboratories) Multifidelity optimization using asynchronous parallel pattern search and space mapping
Abstract: We present a new method designed to improve optimization efficiency using interactions between multifidelity models. It optimizes a high fidelity model over a reduced design space using a direct search algorithm and a specialized oracle. The oracle employs a space mapping technique to map the design space of this high fidelity model to that of a computationally cheaper low fidelity model. Then, in the low fidelity space, an optimum is obtained using gradient based optimization and is mapped back to the high fidelity space. We will review our algorithm, discuss the suitability of APPSPACK for multifidelity optimization, and present some preliminary results.
Giovanna Guidoboni (University of Houston) New perspective for simulating incompressible fluid flows with free boundary
Abstract: The investigation of a fast way of performing numerical simulation of fluid flow with free boundary is motivated by many applications in sciences. The main difficulty lies in the fact that the computational domain is not given a priori but it is another unknown of the problem. Taking advantage of operator splitting techniques, we have been able to avoid the iteration between the solution of the fluid flow and the position of the boundary at each time step and as a consequence our solver is very simple and fast.
Jennifer Suzanne Hruska (Indiana University) Rigorous numerical computations in complex dynamical systems
Abstract: We demonstrate our work in establishing rigorously, via controlled computer arithmetic, certain phenomena of interest in discrete dynamical systems of two complex variables. In particular, we study the family of Henon Mappings f(x,y) = (x^2+c-ay, x), first studied by the Astronomer Henon in the late 1960s, which shares some qualitative similarities to the famed Lorenz differential equations. This family of maps has been widely studied as a diffeomorphism of two real variables, and has a rich variety of chaotic behavior. We extend to consider x,y complex variables, and a,c complex parameters, with the goal of using the extra tools and structure provided by complex analysis to gain insights about the real system contained in the complex system.
Erica Zimmer Klampfl (Ford Motor Company) Women mathematicians: We can do more than teach
Abstract: How many times has someone asked you what your degree is in and when you respond, "Math," they ask, "Oh, do you teach?" While teaching is a noble profession, it is not for everyone. There are other career options for women in the mathematical sciences. I will describe career options that I stumbled upon while job searching during the last phases as a graduate student in applied mathematics, the path I chose, and a brief sampling of some of the research in which I am currently involved.
Satish Kumar (University of Minnesota) Microscale flow and transport problems arising in surfactant rheology, surface patterning, and polymer electrophoresis
Abstract: Fluid flow and transport processes occurring on length scales of microns or less often involve phenomena which are unimportant at larger length scales. Although such phenomena can complicate our ability to understand and design microscale flow and transport processes, they also offer opportunities to engineer novel and useful effects. Three examples will be presented in this talk in support of this idea. In the first example, we consider an instability that arises when a fluid flows past a soft elastic solid. Experiments and theoretical calculations suggest that this instability is responsible for certain rheological phenomena observed in surfactant solutions, and that it may also be useful for enhancing mixing in microscale flows. In the second example, we consider a thin liquid film dewetting near a polymer gel. Numerical simulations using a lubrication-theory-based model which couples the fluid and gel dynamics indicate that the dewetting process can be used to template topographical structures on the gel surface. In the third example, we consider polymer electrophoresis through a narrow slit. Brownian dynamics simulations show that the relationship between the chain transit velocity and chain length depends in a sensitive way on slit dimensions, and suggest the existence of an optimum slit width for electrophoretic separations.
Xiantao Li (University of Minnesota) A multiscale model for the dynamics of solids
Abstract: At the atomic scale, solids can be modeled by molecular mechanics or molecular dynamics, which have become very useful tools in studying crystal structure, defect dynamics and material properties. However due to the computational complexity, the application of these models are usually limited to very small spatial and temporal scales. On the other hand continuum models, such as elasticity, elastodynamics and their finite element (or finite volume) formulations, have been widely used to study processes at much larger scales. But the constitutive relation involved in these continuum models may be ad hoc, and fails to account for the presence of microstructure in the material. In this talk I will present a multiscale model, which couples the atomistic and continuum models concurrently. The macroscale model evolves the system at continuum scale, and the atomistic model, which only involves a small number of atoms, estimate the constitutive data and defect structure. I will show the estimate of the modeling error as well as various applications of this new model.
Martha Paola Vera Licona (Virginia Tech) An Optimization Algorithm for the Identification of Biochemical Network Models
Abstract: An important problem in computational biology is the modeling of several types of networks, ranging from gene regulatory networks and metabolic networks to neural response networks. In [LS], Laubenbacher and Stigler presented an algorithm that takes as input time series of system measurements, including certain perturbation time series, and provides as output a discrete dynamical system over a finite field. Since functions over finite fields can always be represented by polynomial functions, one can use tools from computational algebra for this purpose. The key step in the algorithm is an interpolation step, which leads to a model that fits the given data set exactly. Due to the fact that biological data sets tend to contain noise, the algorithm leads to over-fitting. Here we present a genetic algorithm that optimizes the model produced by the Laubenbacher-Stigler algorithm between model complexity and data fit. This algorithm too uses tools from computational algebra in order to provide a computationally simple description of the mutation rules. We describe applications of the combined algorithm to the modeling of gene regulatory networks, as well as a computational neuroscience project. [LS] Laubenbacher, R. and B. Stigler, A computational algebra approach to the reverse-engineering of gene regulatory networks, J. Theor. Biol. 229 (2004) 523-537.
Hyeona Lim (Mississippi State University) On efficient high-order schemes for acoustic waveform simulation
Abstract: We present new high-order implicit time-stepping schemes for the numerical solution of the acoustic wave equation, as a variant of the conventional modified equation method. For an efficient simulation, the schemes incorporate a locally one-dimensional (LOD) procedure having the fourth-order splitting error. It has been observed from various experiments for 2D problems that (a) the computational cost of the implicit LOD algorithms is only about 40% higher than that of the explicit methods, for the problems of the same size, (b) the implicit LOD methods produce less dispersive solutions in heterogeneous media, and (c) their numerical stability and accuracy match well those of the explicit methods.
Robert P. Lipton (Louisiana State University) Composite properties and microstructure
Abstract: We begin with an overview of composite materials and their effective properties. Most often only a statistical description of the microstructure is available and one must assess the effective behavior in terms of this limited information. To this end approximation schemes such as effective medium schemes and differential schemes are discussed. Variational methods for obtaining tight bounds on effective properties for statistically defined microgeometries are reviewed. Formulas for the effective properties of extremal microgeometries are presented. Such microgeometries include layered materials and sphere and ellipsoid assemblages. Next we focus on physical situations where the interface between component materials play an important role in determining effective transport properties. This is relevant to the study of nanostructured materials in which the interface or interphase between materials can have a profound effect on overall transport properties. Variational methods and bounds are presented that illuminate the effect of particle size and shape distribution inside random composites with coupled heat and mass transport on the interface. We conclude by introducing methods for quantifying load transfer between length scales. This is motivated by the fact that many composite structures are hierarchical in nature and are made up of substructures distributed across several length scales. Examples include aircraft wings made from fiber reinforced laminates and naturally occurring structures like bone. From the perspective of failure initiation it is crucial to quantify load transfer between length scales. The presence of geometrically induced stress or strain singularities at either the structural or substructural scale can have influence across length scales and initiate nonlinear phenomena that result in overall structural failure. We examine load transfer for statistically defined microstructures. New mathematical objects beyond the well known effective elastic tensor are presented that facilitate a quantitative description of the load transfer in hierarchical structures. Several physical examples are provided illustrating how these quantities can be used to quantify the stress and strain distribution inside multi-scale composite structures.
Hailiang Liu (Iowa State University) Wave breaking in a class of nonlocal dispersive wave equations
Abstract: The Korteweg de Vries (KdV) equation is well known as an approximation model for small amplitude and long waves in different physical contexts, but wave breaking phenomena related to short wavelengths are not captured in. We introduce a class of nonlocal dispersive wave equations which incorporate physics of short wavelength scales. The model is identified by the renormalization of an infinite dispersive differential operator and the number of associated conservation laws. Several well-known models are thus rediscovered. Wave breaking criteria are obtained for several typical models including the Burgers-Poisson system, the Camassa-Holm type equation.
Miriam Lucian (Boeing Company) Becoming an applied mathematician - From mathematical logic to airplanes
Abstract: I will describe briefly some the projects I worked on during my Boeing career, emphasizing the role of a mathematician in a manufacturing environment. In this context I will discuss the advantages and drawbacks of working in industry and offer some practical advice to mathematicians at the beginning of their careers.
Maeve McCarthy (Murray State University) Numerical analysis of the Exponential Euler method and its suitability for dynamic clamp experiments
Abstract: Real-time systems are frequently used as an experimental tool, whereby simulated models interact in real-time with neurophysiological experiments. The most demanding of these techniques is known as the dynamic clamp, where simulated ion channel conductances are artificially injected into a neuron via intracellular electrodes for measurement and stimulation. Methodologies for implementing the numerical integration of the gating variables in real-time typically employ first-order numerical methods, either Euler (E) or Exponential Euler (EE). EE is often used for rapidly integrating ion channel gating variables. We find via simulation studies that for small time-steps, both methods are comparable, but at larger time-steps, EE performs worse than Euler. We derive error bounds for both methods, and find that the error can be characterized in terms of two ratios: time-step over time-constant, and voltage measurement error over the slope-factor of the steady-state activation curve of the voltage-dependent gating variable. These ratios reliably bound the simulation error and yield results consistent with the simulation analysis. Our bounds quantitatively illustrate how measurement error restricts the accuracy that can be obtained by using smaller step-sizes. Finally, we demonstrate that Euler can be computed with identical computational efficiency as EE.
Elena Nagaeva ([None]) A convergence analysis of generalized iterative methods in finite-dimensional lattice-normed spaces
Abstract: This poster introduces a lattice-normed space approach to study convergence of iterative methods for solving systems of nonlinear operatorequations. Systems of nonlinear operator equations appear in various fields of applied science, e.g. magnetohydrodynamics. A numerical solution of such a system is a multidimensional real vector, which is formed of several "subvectors". Each subvector corresponds to a certain physical quantity of the problem in hand (pressure, temperature, etc.). We formulate local and semilocal convergence conditions for generalized two-step iterative methods in finite-dimensional lattice-normed spaces. Using the lattice-normed space approach makes it possible to determine the convergence domain for each physical quantity of the problem separately.
Myunghyun Oh (Ohio State University) Evans function for periodic waves in infinite cylindrical domain
Abstract: n infinite dimensional Evans function theory is developed for the elliptic eigenvalue problem. We consider an elliptic equation with periodic boundary conditions and define a stability index with Evans function. The key for defining the index is exponential dichotomies for the system. This system has infinite dimensional stable and unstable spaces. We need to address the issue of how to determine Evans function if two infinite dimensional subspaces have nontrivial intersections. We use Galerkin approximation to reduce down these dimensions to finite and show persistence of dichotomies. Our work reveals a geometric criterion, the relative orientation of the linear unstable subspace, and relation to the momentum for instability of periodic waves in infinite cylindrical domain.
Sarah K. Patch (General Electric) Thermoacoustic tomography - Inversion of a spherical radon transform with partial data
Abstract: Thermoacoustic tomography (TCT) is a hybrid imaging technique proposed as an alternative to xray mammography. Radiofrequency (RF) energy is deposited into the breast tissue uniformly in space, but impulsively in time. This heats the tissue causing thermal expansion. Cancerous masses absorb more RF energy than healthy tissue, creating a pressure wave which is detected by standard ultrasound transducers placed on the surface of a hemisphere surrounding the breast. Assuming constant sound speed, the data represent integrals of the tissue's RF absorptivity over a sphere centered about the transducers. The inversion problem for TCT is to recover data from integrals over spheres centered on a hemisphere. We present an inversion formula for the complete data case, where integrals are measured for centers on the entire sphere. We will derive consistency conditions upon TCT data and discuss their implications for reconstructing clinically realizable 1/2-scan data sets.
Natalya Popova (University of Illinois - Chicago) The effect of gravity modulation on the onset of filtrational convection
Abstract: The effect of vertical harmonic oscillations on the onset of convection in an infinite horizontal layer of fluid saturating a porous medium is investigated. Constant temperature distribution is assigned on the rigid impermeable boundaries. The mathematical model is described by equations of filtrational convection in the Darcy-Oberbeck-Boussinesq approximation. Linear analysis of the stability of the quasi-equilibrium state is performed by using the Floquet method. Employment of the continued fractions method allows derivation of the dispersion equation for the Floquet exponent in the explicit form. The Floquet spectrum is investigated analytically and numerically for different values of oscillation frequency and amplitude, and the Rayleigh number. The neutral curves of the Rayleigh number as a function of the horizontal wave number are constructed for the synchronous and subharmonic resonant modes. The regions of parametric instability contoured by these neutral curves are investigated under different values of oscillation frequency and amplitude. Asymptotes for the neutral curves are constructed for the case of high frequency using the method of averaging and, for the case of low frequency, using the WKB method. Analytical, asymptotic and numerical investigation of the system indicates that vertical vibration can be used to control convective instability in a layer of fluid saturating a porous medium.
Lea Popovic (University of Minnesota) Stochastic modeling of macroevolution
Abstract: The use of stochastic models of evolution has been extensively applied on each level of taxonomy (species, genera, families, etc) separately. It is however desirable to ensure hierarchical consistency between them, so that the phylogenetic tree on species is consistent with the phylogenetic tree on genera containing those species. We present the fundamental model that allows for such hierarchical structure. We start with a stochastic model for evolution of species and extend it to higher taxonomic levels allowing for several different grouping schemes.We illustrate the wide range of probabilistic calculations possible within such model: for the shape of trees at each taxonomic level, the fluctuations of population sizes at each level, etc.
Natalie Rojkovskaia (University of Wisconsin - Madison) A story about Yangians
Abstract: We describe the connection between some remarkable matrices with non-commutative coefficients and the quantum groups Yangians.
Ping Sheng (Hong Kong University of Science & Technology) Nanoparticle suspensions with giant electrorheological response
Abstract: In this talk I wish to tell the story of a 10-year effort in search of a better electrorheological (ER) fluid material, leading to the discovery of the giant ER effect, and the crucial role that mathematics and simulations has played in the whole process. Electrorheology denotes the control of a material's flow properties (rheology) through the application of an electric field. ER fluid was discovered sixty years ago. In the early days the ER fluids, generally consisting of solid particles suspended in an electrically insulating oil, exhibited only a limited range of viscosity change under an electric field, typically in the range of 1-3 kV/mm. The study of ER fluid was revived in the 1980's, propelled by the envisioned potential applications, as well as the successful fabrication of new ER solid particles that, when suspended in a suitable fluid, can "solidify" under an electric field, with the strength of the high-field solid state characterized by a yield stress (breaking stress under shear). However, further progress was hindered by the barrier of low yield stress (typically in the range of a few kPa). Starting in 1994, we have adapted the mathematics of composites, in particular the Bergman-Milton representation of effective dielectric constant, to the study of ER mechanism(s) [1-4]. The questions we aim to answer are: (1) the role of conductivity in the ER effect, (2) the role multipole interaction, (3) the ground state microstructure of the high-field state and most importantly (4) the upper bounds in the yield stress and shear modulus of the high field solid state. Finding the answer to (4) led to the suggestion of the coating geometry for the ER solid particles which can optimize the ER effect, but at the same time also pointed out the limitation of the ER mechanism based on induced polarization. The subsequent study of adding controlled amount of water to the ER fluid pointed to the intriguing possibility of using molecular dipoles as the new "agent" for enhancing the ER effect [5]. Working along this direction, the experimentalist W.J. Wen was able to synthesize urea-coated nanoparticles of barium titanyl oxalate which exhibited yield stress in excess of 100 kPa, breaking the yield stress upper bound and pointing to a new paradigm in ER effect in which the molecular dipoles can be harnessed to advantage in controllable, reversible liquid-solid transitions with a time constant on the order of 1 msec. We propose the model of aligned surface dipole layers in the contact area of the coated nanoparticles to explain the observed giant ER effect [6], with the electric-field induced dissociation (the Poole-Frenkel effect) of the molecular dipoles accounting for the observed ionic conductivity. Quantitative agreement between theory and experiment was obtained. The talk concludes with an outline of the intriguing questions yet to be answered, and the problems to be solved before ER fluids can become a commercial reality. [1] H.R. Ma, W.J. Wen, W.Y. Tam, and P. Sheng, Phys. Rev. Lett. 77, 2499 (1996). [2] W.Y. Tam, G.H. Yi, W.J. Wen, H.R. Ma, M.M. T. Loy, and P. Sheng, Phys. Rev. Lett. 78, 2987 (1997). [3] W.J. Wen, N. Wang, H.R. Ma, Z.F. Lin, W.Y. Tam, C.T. Chan, and P. Sheng, Phys. Rev. Lett. 82, 4248 (1999). [4] H.R. Ma, W.J. Wen, W.Y. Tam and P. Sheng, Adv. Phys. 52, 343 (2003). [5] W.J. Wen, H.R. Ma, W.Y. Tam and P. Sheng, Phys. Rev. E55, R1294 (1997). [6] W.J. Wen, X.X. Huang, S.H. Yang, K.Q. Lu and P. Sheng, Nature Materials 2, 727 (2003).
Suzanne Sindi (University of Maryland) A symbolic dynamical system for reconstructing repetitive DNA
Abstract: The task of assembling a genome is a complicated lengthy process. When a genome is first published it is usually little more than a draft of the regions of the genome that can be uniquely reconstructed. The repetitive regions of the genome are much harder to assemble and are usually finished at later phases with more expensive processes. Here we describe a method for using a Symbolic Dynamical System to reconstruct sufficiently complex regions of repetitive DNA. We demonstrate the ability of our method to reconstruct repetitive DNA using only information available in the early stages of genome assembly.
Nicoleta Tarfulea (University of Minnesota) A mathematical model for cell movement in tumor induced angiogenesis
Abstract: Angiogenesis - proliferation of new capillaries from preexisting ones - is a natural and complicated process. It is regulated by the interaction between various cell types (e.g. endothelial cells (ECs), macrophages) and factors (angiogenic promoters such as VEGF and inhibitors such as angiostatin, extracellular matrix). It involves a series of changes in expression of genes, enzymes, and signaling molecules in tumor cells and ECs, as well as changes in the motility of ECs. In recent years, tumor-induced angiogenesis has become an important field of research since it represents a crucial step in the development of malignant tumors. In this poster, a biologically realistic model for motile endothelial cells is proposed. A new reaction-diffusion system is used to incorporate the signaling mechanism in early stages of tumor angiogenesis (signal transduction as well as cell-cell signaling). The ECs are being modeled as deformable viscoelastic ellipsoids. We present preliminary results that mimic the experiments done in endothelial cell cultures placed on Matrigel film. Also, the model gives further insides into the aggregation patterns by investigating factors that influence stream formation.
Michelle Wagner (National Security Agency) Building a career at the NSA
Abstract: If you are looking for an environment where you can bring your mathematical background and talents to bear on problems that really make a difference, then the National Security Agency (NSA) could be the place for you. In this talk I will describe our training programs for new mathematicians, the many ways in which mathematics comes into play at the NSA, some of the opportunities for advancement throughout a career at the NSA, and the unique opportunities for female mathematicians at the Agency.
Diana Woodward (Societe Generale) Mathematics of risk management
Abstract: In 1996, I made the transition to Wall Street from academia, where I had been an assistant professor of mathematics for almost 10 years. Based on my experiences, I will give an overview of some of the jobs available to mathematicians on the sell-side and buy-side of the street: from investment banking to hedge fund management. I will then briefly discuss the mathematical skills needed to work in quantitative finance today, and introduce the basic mathematical framework of quantitative finance. I will present some of the numerical and analytical research problems I have worked on in stochastic volatility modeling and credit derivatives, and potential research directions in these areas.
Baisheng Yan (Michigan State University) Singular Solutions to a Regular Problem
Abstract: The n-dimensional (quasi)conformal mappings are defined by a first-order partial differential relation (pdr): nabla u(x)in K, with a set K of n x n matrices that is very regular in the sense of Morrey's quasiconvexity. However, such a pdr can have very singular solutions if considered outside the natural Sobolev space. In this talk, I will discuss how Mueller-Sverak's idea of the Gromov convex integration method can be applied to construct the singular solutions with a dense set of singularities.
Visitors in Residence
Alejandro Acuna University of New Mexico 2/6/2005 - 2/9/2005
Negus Adefris 3M 2/7/2005 - 2/9/2005
Sharf U. Ahmed H. B. Fuller Company 2/7/2005 - 2/9/2005
Natalia Alexandrov NASA Langley Research Center 2/3/2005 - 2/6/2005
Haseena Amed Iowa State University 2/3/2005 - 2/6/2005
Iana Anguelova University of Illinois - Urbana-Champaign 2/4/2005 - 2/6/2005
Douglas N. Arnold University of Minnesota 7/15/2001 - 8/31/2006
Donald G. Aronson University of Minnesota 9/1/2002 - 8/31/2005
Gerard Awanou University of Minnesota 9/2/2003 - 8/31/2005
Natalie Axtell Purdue University 2/3/2005 - 2/6/2005
Yelda Aydin University of Illinois - Urbana-Champaign 2/4/2005 - 2/6/2005
Allison Baker Lawrence Livermore National Laboratories 2/3/2005 - 2/6/2005
David Baraff Pixar Animation Studios 2/9/2005 - 2/10/2005
Eric Barth Kalamazoo College 2/11/2005 - 2/21/2005
Katherine Bartley University of Nebraska-Lincoln 2/3/2005 - 2/6/2005
Patricia Bauman Purdue University 2/6/2005 - 2/19/2005
Pam Binns Honeywell 2/4/2005 - 2/5/2005
Fulvio Bisi Università di Pavia 1/8/2005 - 2/5/2005
Stefanella Boatto McMaster University, Canada 2/3/2005 - 2/6/2005
Vena Pearl Bongolan-Walsh Illinois Institute of Technology 2/3/2005 - 2/6/2005
Kathryn E. Brenan Aerospace Corporation 2/3/2005 - 2/6/2005
Joseph P. Brennan North Dakota State University 2/6/2005 - 2/10/2005
LaKeisha Brown East Tennessee State University 2/3/2005 - 2/6/2005
Ronert E. Burgmeier Boston Scientific 2/7/2005 - 2/9/2005
Barbara Butterfield HUMANED 2/3/2005 - 2/4/2005
Maria-Carme Calderer University of Minnesota 9/1/2004 - 6/30/2005
Kristen Jo Campbell Northern Illinois University 2/3/2005 - 2/5/2005
Yiju Chao Morton Consulting Corporation 2/4/2005 - 2/5/2005
Qianyong Chen University of Minnesota 9/1/2004 - 8/31/2006
Margaret Cheney Rensselaer Polytechnic Institute 2/2/2005 - 2/6/2005
Lan Cheng University of Pittsburgh 2/3/2005 - 2/6/2005
Yu-Wen Chiu University of Minnesota 2/4/2005 - 2/5/2005
Agata Comas Rice University 2/3/2005 - 2/6/2005
L. Pamela Cook University of Delaware 1/30/2005 - 2/6/2005
Norman Dancer University of New England, Australia 2/20/2005 - 3/22/2005
Brian DiDonna University of Minnesota 9/1/2004 - 8/31/2006
Brenda Dietrich IBM Corporation 2/4/2005 - 2/5/2005
Elena Dimitrova Virginia Tech 2/3/2005 - 2/6/2005
David C. Dobson University of Utah 2/6/2005 - 2/10/2005
John Anthony Dodson American Express Financial Advisors 2/18/2005 - 2/18/2005
Emad S. Ebbini University of Minnesota 2/24/2005 - 2/24/2005
Ryan S. Elliott University of Michigan 1/1/2005 - 6/30/2005
Maria Emelianenko Pennsylvania State University 2/3/2005 - 2/6/2005
Anandhi Ervadi-Radhakrishnan Medical University of South Carolina 2/3/2005 - 2/6/2005
Andrea Fischbacher SIEMENS AG 2/3/2005 - 2/6/2005
M. Gregory Forest University of North Carolina 2/6/2005 - 2/10/2005
Jennifer Franko Indiana University 2/3/2005 - 2/6/2005
Laura JD Frink Sandia National Laboratories 2/3/2005 - 2/5/2005
Jennifer Belinda Froelich University of Iowa 2/3/2005 - 2/6/2005
Paul Fussell Boeing 2/6/2005 - 2/9/2005
Babu Gaddam 3M 2/7/2005 - 2/9/2005
Tim Garoni University of Minnesota 8/25/2003 - 8/31/2005
Eugene C. Gartland Jr. Kent State University 1/10/2005 - 6/30/2005
Anna Ghazaryan Ohio State University 2/4/2005 - 2/6/2005
Irina Gheorghiciuc University of Delaware 2/3/2005 - 2/6/2005
Sonja Glavaski Honeywell 2/3/2005 - 2/5/2005
Leah H. Gold Texas A & M University 2/3/2005 - 2/6/2005
Yuliya Gorb Pennsylvania State University 2/3/2005 - 2/6/2005
Genetha Anne Gray Sandia National Laboratories 2/3/2005 - 2/6/2005
Giovanna Guidoboni University of Houston 2/3/2005 - 2/6/2005
Robert Gulliver University of Minnesota 9/1/2004 - 6/30/2005
Chuan-Hsiang Han University of Minnesota 9/1/2004 - 8/31/2005
Heather Hardway Rice University 2/3/2005 - 2/6/2005
Jennifer Suzanne Hruska Indiana University 2/3/2005 - 2/6/2005
Roberta Humphreys University of Minnesota 2/4/2005 - 2/5/2005
Qun Huo North Dakota State University 2/6/2005 - 2/9/2005
Randy Jacobus ASA LLC 2/11/2005 - 2/11/2005
Richard D. James University of Minnesota 9/1/2004 - 6/30/2005
Robert M. Jennings 3M 2/7/2005 - 2/9/2005
Shi Jin University of Wisconsin 1/4/2005 - 6/30/2005
Sookyung Joo University of Minnesota 9/1/2004 - 8/31/2006
Jyotana Joshi PMB Gujarati Science College 2/6/2005 - 2/9/2005
George Kamberov Stevens Institute of Technology 2/17/2005 - 2/17/2005
Chiu Yen Kao University of Minnesota 9/1/2004 - 8/31/2006
Rinat Kedem University of Illinois - Urbana-Champaign 2/3/2005 - 2/6/2005
Asha Khanna Indian Institute of Forest Management 2/3/2005 - 2/6/2005
Hyunwoo Kim University of Minnesota 2/7/2005 - 2/9/2005
Erica Zimmer Klampfl Ford Motor Company 2/3/2005 - 2/6/2005
Richard Kollar University of Minnesota 9/1/2004 - 8/31/2005
Satish Kumar University of Minnesota 2/25/2005 - 2/25/2005
Matthias Kurzke University of Minnesota 9/1/2004 - 8/31/2006
Frederic Legoll University of Minnesota 9/3/2004 - 8/31/2006
Benedict Leimkuhler University of Leicester 2/1/2005 - 6/2/2005
Suzanne Lenhart University of Tennessee 2/4/2005 - 2/6/2005
Debra Lewis University of Minnesota 7/15/2004 - 8/31/2006
Xiantao Li University of Minnesota 8/3/2004 - 8/31/2006
Martha Paola Vera Licona Virginia Tech 2/3/2005 - 2/6/2005
Hyeona Lim Mississippi State University 2/3/2005 - 2/6/2005
Kelvin Lim University of Minnesota 2/3/2005 - 2/3/2005
Robert P. Lipton Louisiana State University 2/6/2005 - 2/9/2005
Chun Liu Pennsylvania State University 9/1/2004 - 6/30/2005
Hailiang Liu Iowa State University 1/1/2005 - 6/30/2005
Miriam Lucian Boeing Company 2/3/2005 - 2/6/2005
Mitchell Luskin University of Minnesota 9/1/2004 - 6/30/2005
Suping Lyu Medtronic, Inc. 2/7/2005 - 2/9/2005
Maeve McCarthy Murray State University 2/3/2005 - 2/6/2005
Lisa A. Miller University of Minnesota 2/4/2005 - 2/5/2005
Oana Mocioalca Kent State University 2/3/2005 - 2/6/2005
Stefan Mueller Max Planck Institute for Math in the Sciences 2/21/2005 - 3/15/2005
Elena Nagaeva [None] 2/4/2005 - 2/5/2005
Seema Nanda Harvey Mudd College 2/3/2005 - 2/6/2005
Myunghyun Oh Ohio State University 2/3/2005 - 2/5/2005
Miao-Jung Yvonne Ou University of Central Florida 2/4/2005 - 2/9/2005
Jinhae Park University of Minnesota 2/7/2005 - 2/9/2005
Sarah K. Patch General Electric 2/4/2005 - 2/5/2005
Janet Pavelich Lockheed Martin 2/4/2005 - 2/5/2005
Robert Pego Carnegie Mellon University 1/18/2005 - 2/18/2005
Peter Philip University of Minnesota 8/22/2004 - 8/31/2006
Maria Ponomorenko University of Minnesota 2/4/2005 - 2/5/2005
Silvia Popa University of Wyoming 2/3/2005 - 2/6/2005
Natalya Popova University of Illinois - Chicago 2/3/2005 - 2/6/2005
Lea Popovic University of Minnesota 9/2/2003 - 8/31/2005
Jennifer Proft University of Texas - Austin 2/3/2005 - 2/6/2005
Natalie Rojkovskaia University of Wisconsin - Madison 2/4/2005 - 2/6/2005
Amy Rovelstad Corning Incorporated 2/6/2005 - 2/9/2005
Jacob Rubinstein Indiana University 2/9/2005 - 2/12/2005
Piotr Rybka Warsaw University 1/23/2005 - 2/22/2005
Rolf Ryham Pennsylvania State University 9/1/2004 - 6/30/2005
Arnd Scheel University of Minnesota 7/15/2004 - 8/31/2006
George R Sell University of Minnesota 9/1/2004 - 6/30/2005
Shaun Sellers Washington University - St. Louis 2/27/2005 - 3/16/2005
Ping Sheng Hong Kong University of Science & Technology 2/5/2005 - 2/15/2005
Amit Shesh University of Minnesota 2/10/2005 - 2/10/2005
Tien-Tsan Shieh Indiana University 9/1/2004 - 6/30/2005
Suzanne Sindi University of Maryland 2/3/2005 - 2/9/2005
Robert D. Skeel Purdue University 2/21/2005 - 2/24/2005
Valery P. Smyshlyaev University of Bath 2/1/2005 - 3/3/2005
James Sorensen 3M 2/7/2005 - 2/9/2005
Marie Louise Spilde University of Nebraska 2/3/2005 - 2/6/2005
Daniel Spirn University of Minnesota 9/1/2004 - 6/30/2005
Sandra Spiroff University of Utah 2/4/2005 - 2/6/2005
Peter J. Sternberg Indiana University 8/15/2004 - 6/15/2005
Vladimir Sverak University of Minnesota 9/1/2004 - 6/30/2005
Chris R. Sweet University of Leicester 2/7/2005 - 3/15/2005
Peter Takac Universitaet Rostock 1/23/2005 - 2/12/2005
Nicoleta Tarfulea University of Minnesota 2/4/2005 - 2/5/2005
Jane W. Tucker Duke University 2/3/2005 - 2/4/2005
Mark E. Tuckerman New York University - Courant Institute 2/7/2005 - 2/13/2005
Paul Tupper McGill University, Canada 2/19/2005 - 2/26/2005
Darrel Untereker Medtronic, Inc. 2/7/2005 - 2/8/2005
Paula Andrea Vasquez University of Delaware 1/30/2005 - 2/6/2005
Shankar Venkataramani University of Arizona 2/19/2005 - 3/12/2005
Maria Grazia Viola Texas A & M University 2/3/2005 - 2/6/2005
Epifanio G. Virga Universita di Pavia 2/25/2005 - 3/25/2005
Michelle Wagner National Security Agency 2/3/2005 - 2/5/2005
Qi Wang Florida State University 1/31/2005 - 5/15/2005
Stephen J. Watson Northwestern University 9/1/2004 - 6/30/2005
Diana Woodward Societe Generale 2/4/2005 - 2/5/2005
Baisheng Yan Michigan State University 9/1/2004 - 6/30/2005
Liron Yatziv University of Minnesota 2/10/2005 - 2/10/2005
Aaron Nung Kwan Yip Purdue University 1/16/2005 - 6/30/2005
Emmanuel Yomba University of Ngaoundéré 10/6/2004 - 8/31/2005
Hui Zhang Beijing Normal University 1/21/2005 - 3/1/2005
Xiaoyu Zheng University of North Carolina 2/6/2005 - 2/9/2005
Johannes Zimmer Max-Planck-Institute for Math in the Sciences 1/23/2005 - 2/6/2005
Legend: Postdoc or Industrial Postdoc Long-term Visitor

Participating Institutions: Carnegie Mellon University, Consiglio Nazionale delle Ricerche (CNR), Georgia Institute of Technology, Indiana University, Iowa State University, Kent State University, Lawrence Livermore National Laboratories, Los Alamos National Laboratory, Michigan State University, Mississippi State University, Northern Illinois University, Ohio State University, Pennsylvania State University, Purdue University, Rice University, Sandia National Laboratories, Seoul National University (BK21), Seoul National University (SRCCS), Texas A & M University, University of Chicago, University of Cincinnati, University of Delaware, University of Houston, University of Illinois - Urbana-Champaign, University of Iowa, University of Kentucky, University of Maryland, University of Michigan, University of Minnesota, University of Notre Dame, University of Pittsburgh, University of Texas - Austin, University of Wisconsin, University of Wyoming, Wayne State University
Participating Corporations: 3M, Boeing, Corning, ExxonMobil, Ford Motor Company, General Electric, General Motors, Honeywell, IBM Corporation, Johnson & Johnson, Lockheed Martin, Lucent Technologies, Motorola, Schlumberger-Doll Research, Siemens, Telcordia Technologies