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Re: [ontolog-forum] Ontological Means for Systems Engineering

To: "[ontolog-forum] " <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "Schiffel, Jeffrey A" <jeffrey.a.schiffel@xxxxxxxxxx>
Date: Fri, 30 Jan 2009 12:41:29 -0600
Message-id: <ECF42862FCA16D41BFA98F8C45F0955405723CA4@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Paola,    (01)

        [Jeff:] I do not mean, however, that they are in a hierarchy of
"is-a" relations. They are in a composition relation to the whole,
"part-of." The hierarchy is found in how the parts work together.    (02)

                [Paola:] if I understand you correctly, I think you may
be pointing to what in my field of work is caled 'holarchies' (as in
holonic manufacture)    (03)

As I understand holarchies in a functioning system, the integration of
the parts leads to an emergent behavior of the whole. There is a
tendency, however, for the developing behavior to have unexpected
consequences if not the relationship among the parts is not carefully
designed. In that sense, I would assume that holons are similar to the
hierarchies I've mentioned, especially in terms of the nesting of
systems and subsystems.    (04)

What I think is missing, however, is the nature of information flowing
between levels of the hierarchy. I suggested a downward request and an
upward response with constraints between levels. As I understand
holarachy, if a component is removed, the entire structure vanishes.
This isn't true of systems, many of which continue to function with
degradation if a part breaks.     (05)

Isn't a holarchy an n-level tree? To study emergence, only three levels
are needed at a time. At any rate, we are both referring to
self-organizing systems, wherein the whole is greater than the sum of
its parts.    (06)

        [Jeff:] The interaction of these may be hard to predict, and
there may be undesirable and unexpected emergent behaviors.     (07)

                [Paola:] as you seem to appreciate the challenges of
emergence in complex systems, I wonder there are any insights in how
formal languages capture and represent such emergence, as I have not yet
gone that far in my research    (08)

It seems that there are two approaches. A bottom-up method from
scientists and engineers delves right into the lower levels and looks at
interactions. A top-down approach from the theorists -- especially the
general systems crowd -- looks into systems behavior and attempts to
drive down to lower levels. Both approaches seem to be inadequate so
far. Some good work is being done by the computational intelligence
people, particularly those involved with agent-oriented or distributed
systems. My personal interest is two-fold: in a semiotics view of
requirements engineering, and in command and control of large networked,
geographically dispersed systems.    (09)

Regards,    (010)

-- Jeff    (011)

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