Re:Interview with Terence Tao
by graycat on Monday September 29, 2014 @11:32AM
(#8383356)
> control purposes
Here you have an implicit assumption that the system
being controlled can react, that is, in the sense of
control theory, change its plant dynamics, due to the
effort of the control. Well, for a lot of work in
control, say, in most aerospace applications, that
assumption is false or essentially so. Then
getting a good metric and using it is fine.
E.g., get the power spectrum of ocean wave noise
and use that in a control system to keep
a submarine at essentially a constant depth.
We don't expect that the metric of the
ocean wave power spectrum and the control system in the
submarine will change the ocean very much!
E.g., GPS is a terrific metric, but we don't expect
that using it will change the shape of the earth.
Here you have an implicit assumption that the system being controlled can react, that is, in the sense of control theory, change its plant dynamics, due to the effort of the control. Well, for a lot of work in control, say, in most aerospace applications, that assumption is false or essentially so. Then getting a good metric and using it is fine.
E.g., get the power spectrum of ocean wave noise and use that in a control system to keep a submarine at essentially a constant depth. We don't expect that the metric of the ocean wave power spectrum and the control system in the submarine will change the ocean very much!
E.g., GPS is a terrific metric, but we don't expect that using it will change the shape of the earth.
Etc.