Transport lag modelling

[From: Chris Love (920518.0845)]
[To: Rick Marken (920517)]

Thanks for the quick response Rick. Concerning your views on modelling...

I think the most important goal of all modeling (in psychology) is to build a

>model that behaves quantitatively like a living system. I think the model

should also be true to what we know of the physiology; but not be
constrained by it (physiologists can be wrong,too) or pushed by it (so that
a lot of unnecessary detail is added before it is needed to make the model
work.

  *We* believe the same in engineering. In most cases we just want to get it
to work first, and worry about whether it's representation fits "the real
world"
later. But since this area is somewhat new to me, I wanted to get some
feelings on how important it was to follow biologically motivated models.
Thus, I will use my version of *transport lag* at each level because it is not
difficult to implement and it appears to be useful. This means a running
average of the signals. I suspect that the difference between two
consecutive percept (or reference) signals will not be large (I will have to
verify this though). If it is not overly large then the idea of a running
average will sufficient to simulate the transport lag. From what Bill said,

[From: Bill Powers (920515.1000)]

An integral-output model (like yours) is required to compensate for
transport lags, implicit in the computing cycles and the definition of it The
best way would be to do exactly simultaneous calculations, and introduce
transport lags as shift registers so you can specify the exact lag at each
level.

  From this I understand Bill to mean, - provide the exact outputs with a
delay of *n*. I think that the difference in output between, say, *n* and
*n+1* will be so negligible that a running average will be sufficient to
provide similar behaviour. What do]ou think Rick?

Well, unfortunately today I have to work on my literature survey. This is the
other part of my contract with Martin. Actually, it is the *primary*
component;
this software development is secondary. I personally like working on the
software more; it's more fun!
That's all for now,
Take care Rick,
Chri