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supports most of the capabilities of CLIPS and is
downward compatible; that is, any expert system
that is written for Jess will probably run with little
or no modification under CLIPS. Although Jess
can run as a standalone program, it can also be
embedded in Java code and manipulated using
its own Java Application Programming Interface
(API) or the basic facilities offered by the javax.
rules API. Jess language code can be developed
in any text editor, but Jess comes with a full fea-
tured development environment based on Eclipse
platform (“Ernest”, 2008).
solving problems in the domain. The inference
engine applies and operates on the knowledge
in the knowledge source to solve problems and
arrive at conclusions. For a knowledge base
K
and a set of data or information
D
on a particular
problem, the procedure of arriving at a decision
or inference is given as: I=M[P(D), K], where the
“processing operator”
P(.)
converts the context
information on the process into a form that is
compatible with
K
. Knowledge-base matching
of the preprocessed information is performed
using the matching operation
M[.]
(Karray and
De Silva, 2004).
Figure 2 shows a pictorial representation of
rule-based reasoning. The production rules are
stored in the long-term memory while the problem-
specific information or facts reside in the short-
term memory. Reasoning is applied to reach a
conclusion about the problem being solved by
applying the contents of the long-term memory
to the facts in the short-term memory.
Expert Systems
Expert systems are computer programs which
solve problems within a limited and a specific
field using data on the problem, knowledge re-
lated to the problem and “intelligent” decision
making capability (Karray and De Silva, 2004;
“Expert Systems”, see: http://media.wiley.com/
product_data/excerpt/). They simulate the thought
process of a human expert to solve complex deci-
sion problems in a specific domain. Figure 1 below
shows the structure of an expert system. The work-
ing memory or database gives the context of the
problem domain and is generally considered to be
a set of useful facts. The knowledge base contains
domain-specific facts and heuristics useful for
J2ME (Java 2 Micro Edition)
J2ME is a platform developed by Sun Microsys-
tems for the development of applications for con-
strained devices i.e. devices that have limitations
on what they can do, especially when compared
to their desktop counterparts. Examples of those
devices include pagers, cellular phones, screen-
phones, digital set-top boxes and car navigation
systems. Some of the constraints these devices
have include small screen sizes, limited memory
space, slow processors, e.t.c. Moreover, J2ME is a
scaled-down version in the Java 2 platforms (Java
2 Standard Edition (J2SE) and Java 2 Enterprise
Edition (J2EE)) aimed at consumer wireless de-
vices. J2ME therefore, allows developers to use the
J2ME toolkits to create applications and programs
for wireless and mobile devices, however, J2ME
is used mostly for developing client applications
i.e. applications which are installed on the con-
sumer's mobile device. J2ME applications have
the capacity to access resources on the Internet
Figure 1. Expert System Structure (Source: http://
media.wiley.com/product_data/excerpt/)
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