Mathematics VS? Agent Based Modeling

Posted by Robert Holmes on
URL: http://friam.383.s1.nabble.com/Mathematics-VS-Agent-Based-Modeling-tp520085p520086.html

The distinction between open and close loop systems reminds me of the
distinction between asking forgiveness and asking permission. An open-loop
system produces some recommended set of parameter settings that a third
party (usually human) can choose to implement or not. A closed-loop system
calculates the parameter settings then goes ahead and applies them anyway.
When I use an ABM to predict the bottlenecks in a supply chain and I then
present the results to the client, that's an open-loop system. When the EBM
in my car's engine management system detects that I've done something dumb
and turns on the ABS, that's a closed-loop system.

(Simulators fall in an interesting grey area: is a simulator an example of
control system or an example of a simulation of a control system? These are
different, especially when things go pear-shaped.)

So my contention is that while ABMs may be great for advisory, open-loop
systems they just aren't robust enough to form the core of a closed-loop
system. How would you feel if the automatic control systems in your car
(plane, nuclear reactor etc.) where all written in NetLogo? ;)

Robert

> -----Original Message-----
> From: Raymond Parks [mailto:[hidden email]]
> Sent: Friday, March 11, 2005 10:47 AM
> To: The Friday Morning Applied Complexity Coffee Group
> Subject: Re: [FRIAM] Mathematics VS? Agent Based Modeling
>
> Robert Holmes wrote:
> > And that got me thinking: has there been any (and I do mean any)
> > real-world examples of using an ABM in a closed-loop control system
> > (i.e. one that doesn't just produce some estimates of a control
> > paramter but actually enacts them)? Such control systems are all
> > around us and - as far as I can make out - they are all
> examples of EBMs (even the analogue ones).
>
>    I don't have the web-site URL off-hand, but I believe that
> a German control system company specializing in oil and gas
> pipelines mentioned that their simulator uses an ABM.  The
> simulator's practical purpose is to estimate when different
> substances pumped through the pipeline reach the various
> egress points.  Different "loads" are separated by slugs, but
> they move through the pipeline according the individual
> physics of each load.  Fuel oil moves slower than avgas, for
> instance, and the pressures vary.  There are other simulators
> in use in that industry for leak detection, but I believe
> those are EBM.
>
> --
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