Papers in Neuroprose Archive
Trent Lange
lange at CS.UCLA.EDU
Wed Sep 2 07:21:33 EDT 1992
The following two reprints have been placed in the Neuroprose
Archives at Ohio State University:
======================================================================
Lexical and Pragmatic Disambiguation and Reinterpretation
in Connectionist Networks
Trent E. Lange
Artificial Intelligence Laboratory
Computer Science Department
University of California, Los Angeles
Lexical and pragmatic ambiguity is a major source of uncertainty
in natural language understanding. Symbolic models can make high-
level inferences necessary for understanding text, but handle ambiguity
poorly, especially when later context requires a reinterpretation of
the input. Structured connectionist networks, on the other hand, can
use their graded levels of activation to perform lexical disambiguation,
but have trouble performing the variable bindings and inferencing
necessary for language understanding. We have previously described a
structured spreading-activation model, ROBIN, which overcomes many of
these problems and allows the massively-parallel application of a large
class of general knowledge rules. This paper describes how ROBIN uses
these abilities and the contextual evidence from its semantic networks to
disambiguate words and infer the most plausible plan/goal analysis of
the input, while using the same mechanism to smoothly reinterpret the
input if later context makes an alternative interpretation more likely.
We present several experiments illustrating these abilities and comparing
them to those of other connectionist models, and discuss several directions
in which we are extending the model.
*
Appears in International Journal of Man-Machine Studies, 36: 191-220. 1992.
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REMIND:
Retrieval From Episodic Memory by INferencing and Disambiguation
Trent E. Lange
Artificial Intelligence Laboratory
Computer Science Department
University of California, Los Angeles
Charles M. Wharton
Department of Psychology
University of California, Los Angeles
Most AI simulations have modeled memory retrieval separately from
language understanding, even though both activities seem to use many of
the same processes. This paper describes REMIND (Retrieval from
Episodic Memory through INferencing and Disambiguation), a structured
spreading-activation model of integrated text comprehension and
episodic reminding. In REMIND, activation is spread through a semantic
network that performs dynamic inferencing and disambiguation to infer a
conceptual representation of an input cue. Because stored episodes are
associated with concepts used to understand them, the spreading-activation
process also activates any memory episodes in the network that share
features or knowledge structures with the cue. After the cue's conceptual
representation is formed, the network recalls the memory episode having
the highest activation. Since the inferences made from a cue often
include actors' plans and goals only implied in a cue's text, REMIND is
able to get abstract, analogical remindings that would not be possible
without an integrated understanding and retrieval model.
*
To appear in J. Barnden and K. Holyoak (Eds.), Advances in Connectionist
and Neural Computation Theory, Volume II: Analogical Connections.
Norwood, NJ: Ablex.
======================================================================
Both papers are broken into two (large) postscript files stored in
compressed tarfiles. To obtain a copy via FTP (courtesy of Jordan Pollack):
unix% ftp archive.cis.ohio-state.edu (or 128.146.8.52)
Name: anonymous
Password: (type your E-mail address)
ftp> cd pub/neuroprose
ftp> binary
ftp> get lange.disambiguation.tar.Z
ftp> get lange.remind.tar.Z
ftp> quit
unix% zcat lange.disambiguation.tar.Z | tar -xvf -
unix% lpr -s -P<local-printer> lange.disambiguation1.ps
unix% lpr -s -P<local-printer> lange.disambiguation2.ps
unix% zcat lange.remind.tar.Z | tar -xvf -
unix% lpr -s -P<local-printer> lange.remind1.ps
unix% lpr -s -P<local-printer> lange.remind2.ps
Note that the -s option for lpr is needed for most printers because
of the large size of the uncompressed postscript files (~ 1 meg each).
Sorry, no hard copies available.
Trent Lange
Artificial Intelligence Laboratory
Computer Science Department
University of California, Los Angeles
Los Angeles, CA 90024
E-Mail Address: lange at cs.ucla.edu
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