Second, engineering research employs many semi-empirical methods that are foreign to pure scientific research, one example being the method of parameter variation.
Also, the effect of parameter variations on the equilibrium orbit are omitted.
Allocation: identifies the allowable amount of parameter variation that will improve response variation to a desired level.
Process corners represent the extremes of these parameter variations within which a circuit that has been etched onto the wafer must function correctly.
This allows one to describe the system's behavior on the basis of a small number of limit cases over the whole range of parameter variations.
It does not say anything directly regarding the effect of parameter variations on the equilibrium periodic orbit.
The robustness of the oscillatory behaviour to single parameter variations was quantified using bifurcation analysis.
In this case "parameter variation" was used to map-out and survey a subject where no comprehensive scientific theory (in physics) existed.
High-gain feedback is a simple example of a robust control method; with sufficiently high gain, the effect of any parameter variations will be negligible.
Remember, he told me in color, that one of the possible parameter variations is size.