[Top] [All Lists]

Re: [ontolog-forum] Architecture of Intelligent Systems - Flexible Modul

To: ontolog-forum@xxxxxxxxxxxxxxxx
From: John F Sowa <sowa@xxxxxxxxxxx>
Date: Wed, 27 May 2015 14:44:28 -0400
Message-id: <5566108C.8030601@xxxxxxxxxxx>
Michael and Rich,    (01)

> As the most simple systems are Turing complete, I'd say what
> a system *can* do is not relevant, only what it actually does    (02)

Yes indeed.  "The proof is in the pudding."  The first point I'd
cite is the evidence for Linda (which was one of the inspirations
for the FMF).  Following is an article (from 1992) about the way
14 workstations connected by Linda outperformed a Cray supercomputer:
http://www.nytimes.com/1992/01/19/business/david-gelernter-s-romance-with-linda.html    (03)

Bill Joy was sufficiently inspired by Linda, that he used it as the
basis for Jini and Java spaces.  At VivoMind, the FMF has proved to
be a highly flexible system for rapidly implementing custom designs
for special purpose software.  For some examples, see
    http://www.jfsowa.com/talks/goal7.pdf    (04)

As for performance, the space overhead for one agent is about 1K bytes
(plus whatever space the application uses).  In one test, the FMF used
thousands of agents to process 14 terabytes of data on a machine with
8 CPUs in 15 minutes.  When 7 CPUs were turned off, it took almost
2 hours.  That's almost linear scaling.  (The data was provided by the
client, and the VivoMind system generated better results in less time
than the previous software that the client had been using.)    (05)

> Re the blackboard with lotsa agents reading and writing, how do you
> handle lock and deadlock issues?    (06)

Very simple.  There are no locks.  Hence, no deadlocks.  For that
example above, the data was read-only.  So locks were unnecessary.    (07)

If you need a strategy for serializing something, you can implement
an agent that owns a critical resource and uses its own policy to
restrict access.  You also take a commercial DB (or any system of any
size), put an FMF wrapper around it to make it look like an FMF agent.    (08)

Besides Jini for Java spaces, Linda also inspired other versions of
"tuple spaces".  But many people criticized them because the blackboard
becomes a centralized point of contention.  But the FMF allows you to
have any number of blackboards.  It also allows you to send messages
directly if you know the id of the agent you want to invoke.    (09)

> If you only let one agent perform a complete activity at one time,
> that would avoid both lock and deadlock, but would waste the
> opportunity to use many cpus in the process.    (010)

Note that there are no locks on the "tuple spaces" called the Semantic
Web.  People just hope that the thing at the pointy end of a URL stays
the same while they process it.    (011)

The FMF makes no assumptions about what any agent does.  If updates
are critical, an agent can call Oracle or DB2.  However, most AI
systems for NLP and informal reasoning make do with any data they get.
If time is critical, an agent can make a decision based on whatever
info it has when the deadline hits.  That's what people do -- and
they're smarter than any current AI system.    (012)

John    (013)

Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J    (014)

<Prev in Thread] Current Thread [Next in Thread>