# acronyms, cinnamons, and syzygy

Will you guys please have mercy. I now am grinding my way through five
books on PCT. In Power's (1973) book he included a decent glossary. But the
e-mail alphabet soup terms drown me. Does someone have an up to date
glossary?
RMS, CEV, ECU! Give us a break! Stop the graffitti spray. Tell us poor
idiots what the letters stand for.
Ellery

[Martin Taylor 960625 18:10]

Ellery Lanier Tue, 25 Jun 1996 15:06:56

RMS, CEV, ECU! Give us a break! Stop the graffitti spray.

Sorry--we tend to use short forms when we get into continuous exchanges.

RMS is a term used in electrical engineering and statistics. It stands for
"Root Mean Square", and in effect it means the amount of variability of
something. Square the values of the deviations from the average, find the
mean of those squares, and take the square root of that mean.

I'm afraid I'm guilty of coining the other two acronyms.

CEV= Complex Environmental Variable. It refers to any function whatever
of physical observables. It is commonly used to refer to an aspect of the
"real" world that is defined by the form of the perceptual function of
an ECU (see below). Perceptual functions can define ANY combination of
physical observables, no matter how complex or how extended in time.
Sometimes people use "CEV" to mean "Controlled Environmental Variable"
because the CEV in question is usually defined by a perceptual function
whose output is a controlled perceptual signal.

ECU= Elementary Control Unit. It refers to a single control unit that
controls a scalar perceptual variable. The control unit takes input from
below--its "sensory" input to its perceptual function, usually derived
from the perceptual signals of lower-level ECUs--and from above, in the
form of a reference signal. It provides output to higher levels in the
form of its perceptual signal, and to the next lower level in the form of
its output signal. We use "ECU" rather than "control system" because
a control system might be a whole hierarchy or a single scalar ECU. If
it doesn't matter to the argument whether the control is of a single
scalar perception or of a whole complex, we generally use "control system."
If it does matter, we use "ECU" or "complex control system" or "control
hierarchy" or something appropriate to the argument.

Syzygy is what I'm trying to achieve with the information theory
discussion:-)

Hope this helps.

Martin