For non-linear systems, dead beat control is an open research problem.

Sliding mode observers can be designed for the non-linear systems as well.

The co-energy analysis techniques cannot be applied to non-linear systems.

The Flyer was a much more capable non-linear editing system.

The theoretical basis for regime shifts have been developed from the mathematics of non-linear systems.

The separation principle does not hold in general (for example for non-linear systems).

Her research revealed and explained new phenomena of non-linear vibro-impact systems.

Around the same period, two other competitors provided non-linear systems that required special hardware-typically cards added to the computer system.

Nearly 20 years later, Avid is still the industry leader in non-linear computer-based editing systems.

For small enough stresses, even non-linear systems can usually be assumed to be linear.