lynne@BRILLIG.UMD.EDU (C Lynne D'Autrechy) (10/14/88)
MIRRORS/II Connectionist Simulator Available
MIRRORS/II is a general-purpose connectionist simulator
which can be used to implement a broad spectrum of connec-
tionist (neural network) models. MIRRORS/II is dis-
tinguished by its support of an extensible high-level non-
procedural language, an indexed library of networks, spread-
ing activation methods, learning methods, event parsers and
handlers, and a generalized event-handling mechanism.
The MIRRORS/II language allows relatively inexperienced
computer users to express the structure of a network that
they would like to study and the parameters which will con-
trol their particular connectionist model simulation. Users
can select an existing spreading activation/learning method
and other system components from the library to complete
their connectionist model; no programming is required. On
the other hand, more advanced users with programming skills
who are interested in research involving new methods for
spreading activation or learning can still derive major
benefits from using MIRRORS/II. The advanced user need only
write functions for the desired procedural components (e.g.,
spreading activation method, control strategy, etc.). Based
on language primitives specified by the user MIRRORS/II will
incorporate the user-written components into the connection-
ist model; no changes to the MIRRORS/II system itself are
required.
Connectionist models developed using MIRRORS/II are not
limited to a particular processing paradigm. Spreading
activation methods, and Hebbian learning, competitive learn-
ing, and error back-propagation are among the resources
found in the MIRRORS/II library. MIRRORS/II provides both
synchronous and asynchronous control strategies that deter-
mine which nodes should have their activation values updated
during an iteration. Users can also provide their own con-
trol strategies and have control over a simulation through
the generalized event handling mechanism.
Simulations produced by MIRRORS/II have an event-
handling mechanism which provides a general framework for
scheduling certain actions to occur during a simulation.
MIRRORS/II supports system-defined events (constant/cyclic
input, constant/cyclic output, clamp, learn, display and
show) and user-defined events. An event command (e.g., the
input-command) indicates which event is to occur, when it is
to occur, and which part of the network it is to affect.
Simultaneously occurring events are prioritized according to
user specification. At run time, the appropriate event
handler performs the desired action for the currently-
occurring event. User-defined events can redefine the work-
ings of system-defined events or can create new events
needed for a particular application.
MIRRORS/II is implemented in Franz Lisp and will run
under Opuses 38, 42, and 43 of Franz Lisp on UNIX systems.
It is currently running on a MicroVAX, VAX and SUN 3. If
you are interested in obtaining more detailed information
about the MIRRORS/II system see D'Autrechy, C. L. et al.,
1988, "A General-Purpose Simulation Environment for Develop-
ing Connectionist Models," Simulation, 51, 5-19. The
MIRRORS/II software and reference manual are available for
no charge via tape or ftp. If you are interested in obtain-
ing a copy of the software send your U.S. Mail address via
e-mail to
mirrors@mimsy.umd.edu
or
...!uunet!mimsy!mirrors
or send your U.S. Mail address to
Lynne D'Autrechy
University of Maryland
Department of Computer Science
College Park, MD 20742
and we will send you back a license which you must sign and
return to us and further instructions on how to obtain the
MIRRORS/II software and manual.