Stewart D. Johnson

Photo of Stewart D. Johnson

Professor of Mathematics, Emeritus

413-597-2166
At Williams since 1990

Education

B.A. Fort Lewis College (1979)
Ph.D. Stanford University, Mathematics (1985)

Areas of Expertise

Dynamical Systems, Optimal Control, Math Modeling, Evolutionary Dynamics.

Scholarship/Creative Work

Computing Minimum Time Paths with Bounded Acceleration (2013) arXiv:1310.5905 [math.NA]

Theoretical Considerations of Fisher’s Theorem in Small At-Risk Population, Bulletin of Mathematical Biology: Volume 72, Issue 1 (2010), Page 221-229

Baserunner’s Optimal Path,with Davide Carozza and Frank Morgan,  The Mathematical Intelligencer, online 6 November 2009.

Cyclic Approximation to Stasis, with Jordan Rodu, Electronic Journal of Differential Equations, Vol. 2009(2009), No. 80, pp. 1-16.

Optimality of Stasis and Small Switching Cycles in Planar Systems with Two-Valued Controls, SIAM Journal of Control and Optimization, Vol 43 No 6, pp 1987-1999 (2005).

Planar Hybrid Systems, With John Guckenheimer; Hybrid Systems II, Springer Verlag Lect. Notes in Comp. Sci., (1995).

Simple Hybrid Systems, Int. J. of Bif. & Chaos, #4:6 (1994).

Sex ratio and population stability, OIKOS #69:1, 172-176 (1994).

Beyond Hyperbolicity: Expansion Properties of One-Dimensional Mappings, With John Guckenheimer; From Topology to Computation: Proceedings of the Smalefest, Springer-Verlag, (1993).

Absorbing Cantor Sets and Trapping Structures, Ergodic Theory and Dynamical Systems, #11, 731-736, (1991).

Distortion of S-Unimodal Maps, With John Guckenheimer, Annals of Mathematics, #132, 71-130 (1990) .

Continuous Measures in One Dimension, Communications in Mathematical Physics, #122, 293-320 (1989).

Singular Measures Without Restrictive Intervals, Communications in Mathematical Physics, #110, 185-190 (1987).