We illustrate some recent developments in the theory of dynamical systems. Concentrating on periodically forced second-order ordinary differential equations, and using the Josephson (pendulum) and Duffing equations as examples, we show how the method of symbolic dynamics allows one to study complicated (chaotic) invariant sets in the Poincaré maps of… (More)

@article{Hockett1987NonlinearOI,
title={Nonlinear oscillators, iterated maps, symbolic dynamics, and knotted orbits},
author={Karen Hockett and Patrick Holmes},
journal={Proceedings of the IEEE},
year={1987},
volume={75},
pages={1071-1080}
}