Hi Bill:

I would like to say ask a few things about the elementary

control module (ECM).

With respect to the basic closed loop diagram:

## ···

-----------------

<-----------------|Environment |<----

> ----------------- |

> D(-) ----------------- |

R----(+)->X--Ea------------->| G=??? |--------->O

^ (-) ---------------- |

> ---------------- |

------------------| H=1 |<-----

-----------------

** (D) disturbance, actually the weighted perceptual inputs, are

acting as negative feedback, therefore we should multiply this

by (-1) before adding it into the summer (or subtract it in the

appropriate way).

** The (X) is the summer/comparator junction.

** The (R) reference is the weighted perceptual inputs.

** Ea is the Error signal.

** What is G??? (I can only think that it is FNO + any other

internal functions working on the error signal {This was

deduced from matching the structure of the ECM to that of the

basic negative feedback model})

** Now, since I cannot see what (H) is, I assume it does not

exist as I have drawn it but, exists as the environment (as

drawn).

** Output (O) is what is sent out of the ECM, whether it be to

other ECMs or to the external environment.

This all started when I sat down and tried to model the steady-

state solution. Then I began to think about it and realized that I

didn't really know what (G) was. I mean, after that of course,

you have to abe able to recognize its form, convert it to the (s)

domain, solve for the partial fractions solution, or whatever

method, and finally use the inverse Laplace transforms to get

your steady-state solution, given what ever type input you

provide (Type 1 -step, Type 2 -ramp, etc.). I think these are

basic questions Bill, but I would like to have them clear in my

mind.

Another reason why I started this general analysis is because

I didn't know how to analyze "1+G", in order to determine the

optimum "S" in your dynamic slowing equation!!! So I'm in a bit

of a position...

I have your 1978 paper, "Quantatative analysis of purposive

systems: Some spadework at the foundations of scientific

pyschology", Pyschological Review, pg. 417-435, 1978.

I have started to review it.

Well, that's all. Thank-goodness.

Hope to hear back from you soon,

Chris.