Page 218 - DCAP310_INTRODUCTION_TO_ARTIFICIAL_INTELLIGENCE_AND_EXPERT_SYSTEMS

Introduction to Artificial Intelligence & Expert Systems

Notes process, however, the memory model must identify how an encoded memory can reside in the
memory storage for a prolonged period of time until the memory is accessed again, during the
recall process.

Notes Not all models use the terminology of short-term and long-term memory to explain
memory storage; the Dual-Store theory and refined version of Atkinson-Shiffrin Model of
Memory (Atkinson 1968) uses both short-term and long-term memory storage, but others
do not.

The short-term memory refers to the ability to hold information from immediate past for a
short duration of time. According to the Atkinson-Shiffrin Model of Memory, in the process of
Encoding, perceived memory enters the brain and can be quickly forgotten if the sensory
information is not stored further in the short-term memory. The information is readily accessible
in the short-term memory for only a short time. Baddeley suggested that memory stored in
short-term memory is continuously deteriorating, which can eventually lead to forgetting in
the absence of rehearsal. George A. Miller suggested in his paper that the capacity of the short-term
memory storage is approximately seven items, plus or minus two, but modern researchers are
showing that this itself is subject to numerous variability, including the stored items’ phonological
properties.

11.5.2 Memory Organization with E-MOPs

Roger Schank and his students at Yale University have developed several computer systems
which perform different functions related to the use of natural language, text, knowledge
representation, and memory organization. One system of particular interest was developed by
Janet Kolodner (1983a, 1983b, 1984) to study problems associated with the retrieval and
organization of reconstructive memory. Her system, called CYRUS (Computerized Yale Retrieval
and Updating System) stores episodes from the lives of former secretaries of state Cyrus Vance
and Edmund Muskie. The episodes are indexed and stored in long-term memory for subsequent
use in answering queries posted in English. The system has many of the other features. The basic
memory model in CYRUS is a network consisting of Episodie Memory Organization Packets
(E-MOPs). Each such E-MOP is a frame-like node structure which contains conceptual information
related to different categories of episodic events. E-MOPs are indexed in memory by one or
more distinguishing features.

Example: There are basic E-MOPs for diplomatic meetings with foreign dignitaries,
specialized political conferences, traveling, sight-seeing, negotiations, state dinners, as well as
other basic events related to diplomatic state functions.

The diplomatic-meeting E-MOP, called $MEET, contains information which is common to all
diplomatic meeting events. The common information which characterizes such an E-MOP is
called its content.

!
Caution Use of truth table should be handled carefully.

Task Find the effect of propositional logic in real life.

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