- Visiting faculty, University of New South Wales, June-August, 2002.
- Colloquium speaker, Boston University, March, 2002.
- Invited lecturer, AMS Short Course on Dynamical Systems, UC San Diego, January, 2002.
- Invited speaker, Courant Dynamics Seminar, New York, December, 2001.
- Invited speaker, AMS Special Session on Dynamics, Williams College, October, 2001.
- Invited speaker, Eisenbud seminar on Commutative Algebra, UC Berkeley, March, 2001.
- Invited speaker, AMS Special Session on Dynamics, San Francisco State, December 2000.
- Visiting Faculty, Yale University, August-September, 2000.
- Visiting faculty, Schrödinger Institute for Mathematical Physics, Vienna, June 1-30, 1997, November 6-December 5, 1998, and May 25-June 28, 1999.
- Invited speaker, Workshop on Ergodic Theory of \(\mathbb{Z}^d\)-actions, University of Warwick, April, 2000.
- Invited speaker, AMS Special Session on the Dynamics of \(\mathbb{Z}^d\)-actions, Washington, D.C., January, 2000.
- Invited speaker, Dynamics Seminar, University of Victoria, November, 1999.
- Invited speaker, IMA Conference on Codes, Systems, and Graphical Models, Minneapolis, August, 1999.
- Invited speaker, Conference on Dynamics, University of Maryland, March, 1999.
- Invited principal speaker, Conference on Ergodic Theory and Dynamics, Technical University of Delft, Holland, July 15-30, 1994.
- Invited speaker and participant, Warwick Symposium on \(\mathbb{Z}^d\)-actions, June 1-30, 1994.
- Invited speaker, Conference on Algebraic Systems, C.I.R.M., Luminy, France, June, 1993.
- Invited speaker, Conference on Symbolic Dynamics and its Applications, Yale University, July, 1991.
- Invited speaker, Special session on the geometry of algebraic numbers, Canadian Mathematical Society, Vancouver, August, 1989.
- Invited speaker, Mini-symposium on Coding Theory, SIAM Conference on Discrete Mathematics, San Francisco, June 13, 1988.
- Special lecturer, Computers in Mathematics Lecture Series, IBM Yorktown, March 17, 1988.
- Invited speaker, Conference on Symbolic Dynamics, University of Heidelberg, July, 1987.
- Invited speaker, Conference on Coded Systems, C.I.R.M., Luminy, France, June, 1987.
- Invited speaker, Workshop on Symbolic Dynamics, Warwick University, England, June 21-July 20, 1986.