# Faculty 1995 Travel and Talks

## January 1995

The Joint Mathematics Meetings of the American Mathematical Society and the Mathematical Association of America, held January 4-7, 1995 in San Francisco, California, were attended by Harold Boas, Al Boggess, Richard Fabiano, Arthur Hobbs, David Larson, Edward Letzter, Bill Rundell, Roger Smith, and Mike Stecher.

Harold Boas spoke on "Good domains of finite type" in the Special Session on Geometric Function Theory in One and Several Complex Variables.

Richard Fabiano spoke on "Stability and approximation for a linear viscoelastic model" in the Special Session on Numerical Solution for Integro-Differential Equations.

David Larson spoke on "Preannihilators, the operator approximation property, and dual products" (joint work with Jon Kraus) in the Special Session on Non Self Adjoint Operator Algebras.

Edward Letzter spoke on "On the quantum Frobenius map for general linear groups" in the Special Session on Noncommutative Algebra.

Roger Smith spoke on "Derivations and automorphisms of certain operator algebras" (joint work with Frank Gilfeather) in the Special Session on Non Self Adjoint Operator Algebras.

Mike Stecher spoke on "Row rank equals column rank" in the Special Session on Innovations in Teaching Linear Algebra.

Richard E. Ewing spoke on "Aspects of numerical methods for multiphase flows" at the Second IHP/IAHS George Kovacs Colloquium on Subsurface Flow and Transport: The Stochastic Approach, UNESCO, Paris, France, January 26-28, 1995.

## February 1995

The Third SIAM Conference on Mathematical and Computational Issues in the Geosciences, held February 8-10, 1995 in San Antonio, Texas, was attended by Richard E. Ewing and Raytcho Lazarov.

Richard E. Ewing gave an invited talk on "Mathematical modeling and simulation for applications of fluid flow in porous media".

Raytcho Lazarov spoke on "Domain decomposition methods for mixed finite element approximation to flow problems".

Harold Boas attended the meeting of the Committee of Examiners for the Mathematics Subject Test of the Graduate Record Examination at the Educational Testing Service, Princeton, New Jersey, 17-19 February, 1995.

Edward Letzter attended the conference in honor of Richard E. Block at the University of California at Riverside, 18-20 February, 1995.

Peter Stiller held the TCU Research Fund Lectureship and spoke on "Arithmetic and geometry of elliptic surfaces" at Texas Christian University on February 21, 1995.

## March 1995

Meeting 898 of the American Mathematical Society, held March 3-5, 1995 at the University of Connecticut in Hartford, Connecticut, was attended by Steven D. Taliaferro, who spoke on "Radial symmetry of large solutions of nonlinear elliptic equations" in the Special Session on Nonlinear Boundary Value Problems.

The workshop on Inverse Problems in Wave Propagation, held March 6-17, 1995 at the Institute for Mathematics and Its Applications, was attended by David Dobson; Bruce Lowe; Michael Pilant; and William Rundell, who spoke on "Determination of unknown coefficients from multiple input sources" (joint work with Bruce Lowe).

Meeting 899 of the American Mathematical Society, held March 17-18, 1995 at the University of Central Florida in Orlando, Florida, was attended by Richard E. Ewing and William Rundell.

Richard E. Ewing spoke on "Inverse problems in bioremediation of groundwater contamination" in the Special Session on Inverse and Ill-Posed Problems.

William Rundell spoke on "A quasi-Newton scheme in inverse obstacle scattering" (joint work with Rainer Kress) in the Special Session on Inverse and Ill-Posed Problems.

Meeting 900 of the American Mathematical Society, held March 24-25, 1995 at DePaul University in Chicago, Illinois, was attended by Dante DeBlassie, Gregory Kabatianski, and Edward Letzter.

Dante DeBlassie spoke on "Reflected Brownian motion with drift in a wedge" in the Special Session on Probability and Harmonic Analysis.

Gregory Kabatianski spoke on "Coding and hashing" in the Special Session on Codes and Their Applications.

Edward Letzter spoke on "Prime ideals in quantum algebras at roots of unity" in the Special Session on Hopf Algebras and Quantum Groups.

N. Sivakumar attended the Southeast Atlantic Section meeting of the Society for Industrial and Applied Mathematics held March 24-25, 1995, in Charleston, South Carolina, and spoke in the Minisymposium on Approximation Theory on the topic "On the interpolation of scattered data by radial-basis functions."

## April 1995

Richard E. Ewing delivered a keynote address on "Multidisciplinary interaction in environmental modeling" at the Symposium on Advances and Trends in Computational and Applied Mathematics, Austin, Texas, April 20-22, 1995.

Bill Johnson delivered the Millican Lecture at the University of North Texas.

William Rundell delivered the Charles Edison Lecture to the College of Science at the University of Notre Dame on April 19, 1995, on the topic "Inverse Problems: The Art and Science of Reconstructing Questions from Partial Answers." He also delivered a colloquium lecture to the Department of Mathematics on April 20, 1995, on the topic "Can you hear the Density of a String"?

The Texas A&M University Center for Approximation Theory Annual Symposium was held April 21-22, 1995. Local speakers and their titles were:

Charles Chui, "Orthogonal decomposition and duality principle".

Joseph Lakey, "Divergence-free wavelets in vector Hardy space theory".

Francis Narcowich, "An 'uncertainty principle' for the

*m*-sphere".Peter Oswald, "Applications of the Powell-Sabin split to multilevel methods (for p.d.e.)".

Lefan Zhong, "Interpolation bases, the Marcinkiewicz-Zygmund inequality and Ap weights".

The Midwest Several Complex Variables Meeting, held April 29-30, 1995 at the University of Wisconsin at Madison, was attended by: Harold Boas, Emil Straube, and Jiye Yu.

## May 1995

Meeting 901 of the American Mathematical Society, the International Joint Mathematics Meeting of the AMS and the Israel Mathematical Union, held May 24-26, 1995, in Jerusalem, was attended by Edward S. Letzter, Thomas Schlumprecht, and Joel Zinn.

Doug Hensley attended the International Conference on Analytic Number Theory in honor of Heini Halberstam, May 16-20, 1995, at the University of Illinois at Urbana-Champaign, where he spoke on "The distribution of reciprocal pairs modulo polynomials over a finite field".

Richard E. Ewing spoke on "Modeling and simulation of multiphase contaminant transport in porous media" at the International Conference on Mathematical Modeling of Flow and Transport in Porous Media, St. Etienne, France, May 22-26, 1995.

Bill Johnson visited the University of Kiel, Germany, where he delivered colloquium and seminar talks.

Member of the organizing committee for the Special Session on Functional Analysis.

Gregory Kabatianski spoke on "Packings in Metric Spaces and Linear Programming, with Applications to Discrete Geometry, Graph Theory and Communication" on May 2, 1995 at The Georgia Institute of Technology in Atlanta, Georgia; on "Packings and coverings in Metric Spaces with Applications to Communication" on May 4, 1995 at the University of Connecticut in Storrs, Connecticut; and on "Matroids, Generalized Orthogonal Arrays and Ideal Secret Sharing Schemes" on May 5, 1995 at Northeastern University in Boston, Massachusetts.

Raytcho Lazarov spoke on "Computational techniques in multiphase flow and transport in porous media" at the International Conference on Mathematics and Computations, Reactor Physics, and Environmental Analysis in Portland, Oregon, April 30-May 4, 1995.

Edward S. Letzter spoke on "Nonsplit extensions of simple modules over classical Lie superalgebras" in the Special Session on Associative Algebra.

Gave a 75 minute talk in a workshop on Hopf Algebras at Ben Gurien University of the Negev.

Thomas Schlumprecht spoke "On a Gaussian correlation problem" in the Special Session on Functional Analysis.

Joel Zinn spoke on "Hypercontractivity and a Gaussian correlation inequality" in the Special Session on Functional Analysis.

## June 1995

The Third U.S. National Congress of Computational Mechanics, Dallas, Texas, June 12-14, 1995, was attended by James H. Bramble, Richard E. Ewing, Raytcho Lazarov, Peter Oswald, and Xuejun Zhang. The following papers were presented in the session on Preconditioning Techniques for High Performance Computing:

James H. Bramble, "Least-squares methods for Stokes equations based on a discrete minus one inner product".

James H. Bramble, J. Pasciak, and Xuejun Zhang, "Two level preconditioners for elliptic finite element problems".

James H. Bramble, Xuejun Zhang, and J. Pasciak, "Multigrid methods for biharmonic finite element problems".

H. Chen and Raytcho Lazarov, "Domain splitting methods for mixed finite element approximations to transient convection-diffusion problems".

Kenote Address by Richard E. Ewing, "Application of computational mechanics techniques in energy and environmental applications".

Peter Oswald, "Multilevel preconditioners for nonconforming discretizations".

Richard E. Ewing gave a plenary lecture on "Linear algebra aspects of large-scale models for fluid flow in porous media" at the Second IMACS International Symposium on Iterative Methods in Linear Algebra held in Blagoevgrad, Bulgaria, June 17, 1995.

Gave a plenary lecture on "Mathematical modeling and simulation for applications of fluid flow in porous media" at the International Conference on Advanced Mathematics, Computations, and Applications, AMCA-95, held in Novosibirsk, Russia, June 21-23, 1995. He also spoke on "Substructuring preconditioners for mixed finite element methods for general domains".

Stephen Fulling attended the Sixth Seminar on Quantum Gravity, Institute for Nuclear Research, Moscow, June 12-19, 1995, where he spoke on "Pseudodifferential operators, covariant quantization, the inescapable Van Vleck-Morette determinant, and the

*R*/6 controversy". He also visited the Lebedev Physical Institute, Moscow, June 20-23, 1995, and the Institute for Theoretical Physics, Kiev, June 25-July 2, 1995.

## July 1995

Stephen Fulling attended the Conference on Symmetry in Nonlinear Mathematical Physics at the Institute for Mathematics, Kiev, July 3-9, 1995, where he spoke on Graph expansions and graphical enumeration applied to semiclassical propagator expansions.

Raytcho Lazarov gave a plenary talk on "Mathematical modeling, numerical techniques, and computer simulation of flow and transport in porous media" at the Computational Techniques and Applications Conference held in Melbourne, Australia, July 3-7, 1995.

## August 1995

Richard E. Ewing spoke on "Finite element methods for multiphase transport of contaminants in porous media" at the USEPA Workshop on Next Generation Environmental Models and Computational Methods (NGEMCOM) held in Bay City, Michigan, August 7-9, 1995.

N. Sivakumar visited Imperial College, London, August 2-17, 1995.

## September 1995

The South-Central Regional Texas A&M—Waterloo Maple Conference was held September 23, 1995, at Texas A&M University.

The conference organizers were Philip Yasskin and Christine Becker (Waterloo Maple Software).

Al Boggess spoke on "An Introduction to Maple."

Jeff Morgan spoke on "Teaching Differential Equations with Maple."

Philip Yasskin spoke on "Teaching Calculus with Maple.

Richard E. Ewing gave a plenary lecture on "Multiphase flow simulation for petroleum applications," Modeling and Numerical Methods in Petroleum Engineering, La Marsa, Tunisia, September 20-21, 1995.

Raytcho Lazarov spoke on "Domain splitting algorithm for mixed finite element approximations to parabolic problems" at the Workshop on Iterative Methods for Large Scale Nonlinear Problems held in Logan, Utah, September 14-16, 1995.

Jay Walton attended workshops September 11-22, 1995, on Phase Transitions, Optimal Microstructures and Disordered Materials as part of the special year on Mathematical Methods in Materials Science at the Institute for Mathematics and Its Applications. Accompanying him were graduate students Tanya Leise, Christian Turner, and David Zeigler.

## October 1995

A Workshop in Geometric Analysis was held at Texas A&M University October 20-22, 1995. The Organizing Committee was Huai-Dong Cao and Jon Pitts.

Richard E. Ewing, "Modeling and simulation for multiphase transport of contaminants in porous media," Modeling and Computation in Environmental Sciences, Institut für Computeranwendungen, Stuttgart, Germany, October 12-13, 1995.

Stephen A. Fulling visited the University of Alberta (in Edmonton) to serve as external examiner on a Ph.D. thesis in the Department of Physics and to give a seminar talk on "Surprises in Numerical Quantum Mechanics".

Bruce Lowe was a plenary speaker at the 24th Midwest Differential Equations Conference, October 27-28, 1995, at the University of Nebraska at Lincoln.

Jiye Yu spoke on "Geometry of bounded pseudoconvex domains" at the Department of Mathematics, University of California at Riverside on October 19, 1995.

## November 1995

The workshop on Analytic and PDE Methods in Several Complex Variables at the Mathematical Sciences Research Institute, November 6-10, 1995, was attended by Harold Boas, Emil Straube, and Jiye Yu.

Harold Boas spoke on "Who was Stefan Bergman?"

Emil Straube spoke on "Boundary limits of the Bergman kernel and metric" (joint work with Harold Boas and Jiye Yu).

Speakers at the Eighth Annual International Conference on Technology in Collegiate Mathematics (ICTCM), Houston, Texas, November 16-19, 1995:

Paul S. Ache III, "Mathematical modeling, business calculus, and the graphing calculator".

Vince Schielack, "A course in mathematics and technology for prospective secondary teachers".

Speakers at the second joint meeting of the American Mathematical Society and the Sociedad Matemática Mexicana, Guanajuato, Mexico, November 29-December 2, 1995:

Richard E. Ewing, "Modeling the transport and remediation of contaminants in groundwater," Special Session on Numerical Solutions of Nonlinear Partial Differential Equations.

Paulo Lima-Filho, "Equivariant algebraic suspensions," Special Session on Complex Algebraic Geometry, Singularities and Foliations.

Richard E. Ewing, "Key telecommunications initiatives," The New World of Telecommunications: Redefining Roles in the Era of Technological Advances, The Woodlands, Texas, November 3, 1995.

Jon Pitts spoke on "Computing least area hypersurfaces spanning arbitrary boundaries" at the Texas Geometry and Topology Conference held November 10-12, 1995 at the University of Texas at Austin.

Ying Shen spoke on "Stable minimal surfaces and sphere theorems" (joint work with Shunhui Zhu) at meeting 905 of the American Mathematical Society held at the University of Southern California, Los Angeles, California, November 11-12, 1995.

David Stewart spoke on "Dynamics, friction, and complementarity problems" at the International Conference on Complementarity Problems held at Johns Hopkins University, November 1-4, 1995.

Jiye Yu spoke on "Holomorphic local invariants of bounded pseudoconvex domains" at the Department of Mathematics, University of California at Berkeley on November 3, 1995.

## December 1995

Richard E. Ewing gave an address on "Inverse problems for groundwater contamination and petroleum applications".

William Rundell and Heinz Engl (Johannes-Kepler Universität, Austria) chair the Symposium on Inverse Problems: Geophysical Applications conducted by the Society for Industrial and Applied Mathematics (SIAM) and the Gesellschaft für Angewandte Mathematik und Mechanik (GAMM), Fish Camp, California, December 16-19, 1995.

Otmar Scherzer spoke in the session on Inverse Scattering on "The Landweber iteration for an inverse scattering problem" (joint work with Martin Hanke, Universität Karlsruhe and Frank Hettlich, Universität Erlangen-Nürnberg).

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