Every Good Regulator of a System Must Be a Model of That System (1970) [pdf]

http://pespmc1.vub.ac.be/books/Conant_Ashby.pdf

by tischler • 8 years ago

110 28 8 years ago

pespmc1.vub.ac.be

PaulHoule• 8 years ago

see https://www.amazon.com/Have-Fun-at-Work-Livingston/dp/093706... and https://www.amazon.com/Friends-High-Places-W-Livingston/dp/0... for practical applications of Ashby thinking.

hkon2• 8 years ago

Do you know any other books around the same topic. I'm not sure what good keywords would be for this. Ebooks preferrably. Looks interesting.

walterbell• 8 years ago

Free 2017 ebook with overview of cybernetics: https://www.google.com/amp/newbooksnetwork.com/liss-c-werner...

Many resources: http://pangaro.com/definition-cybernetics.html

kaycebasques• 8 years ago

It’d be nice to list the names of the books, rather than just links. I’m curious about your suggestions, but don’t necessarily want to visit Amazon.

doppelganger27• 8 years ago

The books are "Have Fun at Work" and "Friends in High Places," both by William L. Livingston

aristus2• 8 years ago

It feels like people keep rediscovering the implications of Turing-completness in different domains.

iamcurious• 8 years ago

Would you mind expanding your comment?

jessriedel2• 8 years ago

I don't think anyone doubts that being able to regulate a Turing machine would require a system that is Turing complete. But this seems very far from saying that regulating any system requires a complete (isomorphic) model it. Or did you mean something else?

aristus2• 8 years ago

A surprisingly large number of things that we normally don't think of as computers are Turing-complete. It's a very low bar of complexity. And regulating requires modeling requires simulation. That's what Turing's result says: to know whether a program halts you must run it.

salawat• 8 years ago

Don't know why parent was downvoted...

If one can't make the connection between Turing completeness/automata theory and Neuro-cognititive function...think more.

sytelus• 8 years ago

This is interesting in context of so-called model-free and model-based reinforcement learning.

jey• 8 years ago

I tacitly assumed that "model-free" really meant "model has been marginalized out", i.e. instead of treating it as a function to be estimated/learned through regression. Is that not the case?

amatic• 8 years ago

> modelling might in fact be a necessary part of regulation.

That seems false. PID is used all over, no models. Very simple, very effective.

maxerickson• 8 years ago

One way to look at a PID controller is that it uses a simple model that is correct in a lot of situations.

euyyn• 8 years ago

Yeah tuning the PID controller is in fact modeling the dynamics of the system. You can't really expect an untuned PID controller to just work.

sobellian• 8 years ago

The fact that PID loops work for many systems is a consequence of the dynamics of those systems, for example that the integral of velocity is position and the derivative of velocity is acceleration. A vast array of phenomena can be modeled as 2nd order linear ODEs.

carlmr2• 8 years ago

Which just means that for many things your brain doesn't need a new model, just to parametrize one of the most common models.

xaedes• 8 years ago

linear model

theoh• 8 years ago

I think this Wiki page discusses it: https://en.wikipedia.org/wiki/Internal_model_(motor_control)

nabla9• 8 years ago

Yes. That sentence is generally untrue if the context is not specified.

Either the authors made rudimentary error or they specified the context. If you read forward, they define the problem and discuss error and cause controlled regulation.

ahartmetz• 8 years ago

As a bad physicist ("physics is the art of approximation", some prof said during my studies): Indeed, you only have to model the relevant aspect(s) of the system, which may be completely unrecognizable as the system.

I guess it's somewhat more true in programming, because if you have only ten lines, can you even call it modeling?

That said, I like to say that the best kind of code teaches you something new abou the problem it's solving. Some invariant, widely usable simplification, etc. Still not the same as modeling the system as such, though.

carlmr2• 8 years ago

because if you have only ten lines, can you even call it modeling?

Ten? Do you even Perl?

richard_todd• 8 years ago

I don’t see how the last sentence (the brain must model the environment) follows from the admission on the previous page that a regulator can skip the model by taking on unnecessary complexity. It seems there is a built-in assumption that the brain has no unnecessary complexity, if I am following correctly. I wouldn’t be so sure about that! (Although, I should add, the idea that the brain models its environment sounds intuitively true beyond question... I’m just trying to follow the arguments put forth in the paper itself.)

liquidwax• 8 years ago

LOL. The second paragraph in the abstract starts with "m this paper a theorem is presented […]"

organsnyder• 8 years ago

Probably an OCR error.

adrianmonk• 8 years ago

Especially likely since the Introduction section contains has "i(lea" instead of "idea".

Every Good Regulator of a System Must Be a Model of That System (1970) [pdf]

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