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Module 2: Acquiring the software and installing it on your own Web server
The next step is to download the
applet and sample knowledge bases. This
doesn't take very long: the applet archive and sample files are not lengthy.
For this reason, the applet and knowledge bases are downloaded separately
and are uncompressed so they are ready to use when you receive them.
Conditions of use that you accept when you download e2gLite
Purpose of e2gLite and disclaimers: This software has been developed and is being distributed for educational and experimental purposes. It is a work in progress, and will continue to be a development prototype for some time to come.
No claims are made for its serviceability, and eXpertise2Go.com assumes no responsibility for financial or other harm that occurs due to the use of e2gLite or knowledge bases developed to work with e2gLite or due to decisions made based on use of e2gLite or its knowledge bases.
While reasonable effort is being expended in the ongoing effort to test and debug the program, when you download and use the e2gLite software you become an informal member of the test team! You may not sell e2gLite: e2gLite is free software: eXpertise2Go.com isn’t selling it, so you can’t either. It is OK to incorporate e2gLite into Web sites you develop for compensation, but your client must understand that the e2gLite Java applet is not part of what they are paying for. Knowledge bases delivered by e2gLite are not confidential: Knowledge bases used with e2gLite are text files that may be examined in a browser or with a text editor by anyone with access to the Web site from which they are delivered.
Implementing a knowledge base with this software implies your willingness to make the knowledge public – you are publishing the expertise as you might in an article.
In this regard, you may (and are encouraged to) modify and extend the sample e2gLite knowledge bases included on this Web site. Re-engineering/reverse engineering e2gLite is prohibited: You agree that you will not de-compile and/or modify the e2gLite applet. This prohibition explicitly includes modifying or removing the eXpertise2Go.com logo displayed on the opening screen. The motivation for distributing e2gLite is to attract visitors to the eXpertise2Go.com Web site in hopes of increasing public awareness of expert systems and expanding mass-market usage of the technology, so displaying the logo is important. Redistribution of e2gLite is allowed: You may redistribute copies of the e2gLite applet if you make recipients aware of these conditions of use and don’t charge for the redistribution. New versions of the applet will be created on a continuing basis to correct errors or include new capabilities, so you should check the version number displayed on the opening screen from time to time to keep the version you are redistributing current. Use of e2gLite on commercial Web sites is allowed: Subject to the above conditions, it is OK to incorporate the e2gLite applet and sample knowledge bases in for-profit Web sites.
If you click the demo.html link with the left mouse button, the Web page
will open. To avoid this, click on the link with the right mouse
button, then look for the entry on the menu that will appear that allows you
to save the "target" (Internet Explorer) or "link" (Netscape).
The e2gLite software is provided in an archive file named e2glite.jar.
This file type is similar to a .zip file, and WinZip or other programs
with an unzip capability can unpack its contents. You will simplify the
installation and improve the
performance of the applet loading process if you leave the .jar
file intact. If you want to accommodate old browsers that use
version 1.0.2 of the Java Virtual Machine (JVM) and cannot load
applets from archive files you may also unpack the .jar in the
directory where it is located. This produces a subdirectory
named e2glite that contains all of the .class files required by
the expert system shell. By using this approach, recent browser versions
are able to load the software efficiently, while old versions are still
able to operate. Although e2gLite has been tested successfully on versions of
Netscape as far back as 2.01, software problems have been encountered
with some combinations of MS Windows operating systems and browsers using
old (v. 1.0.2) JVMs. You are strongly advised to perform development
work using Netscape or Internet Explorer versions 4.0+.
Where c:\xxx\yyy... defines the complete path to the file.
This technique is useful for testing knowledge bases, and allows you
to set up a simple Web page with the <APPLET> tags necessary to
load e2gLite and your knowledge base for testing. It is difficult to
construct a complete Web site this way because links embedded in Web
pages are often referenced to Web root directories or to complete
URLs (http://...) and these probably won't work correctly when the linking
page has been loaded as a file on a PC that is not connected to the Internet.
To test this mode with your browser, create a floppy disk containing
e2gLite.jar, demo.html, auto.kb, and admit.kb. Start your browser and type:
a:\demo.html You should see the demo page and should be
able to run the four examples. (Note: it is apparently not possible to
use the Opera browser in this fashion.)
Once you have access to your site, you will usually be able to upload the
applet, Web pages and knowledge bases using the File Transfer Protocol (FTP). The
Web site's provider will have online documentation that tells you how
to do this.
When you have your Web site established, create a subdirectory on your
site named expertsys and load the e2glite.jar, admit.kb,
auto.kb and demo.html files that you have downloaded into this
directory. The demo.html file is setup to run the other demos. So,
load your browser and try the following (appropriately adjusted for the actual
name of your domain):
Expert system development environment options: The options for using
e2gLite include running on a local PC that loads the Web page
that invokes e2gLite as a file, running e2gLite in the Java
appletviewer, running on a local machine on which a Web
server has been installed and running on a Web server that provides
public access. You may want to employ more than one of these alternatives
to develop and provide access to your knowledge bases. The fundamental
requirement is that you are going to have to embed the information
that loads e2gLite and specifies the knowledge base and other
options between special tags
in a Web page (<APPLET...> to </APPLET>) and then load that
Web page to get e2gLite to run.
Loading the Web
page that invokes e2gLite as a file: It is
possible to run applets in the Windows Netscape or Internet Explorer browsers
on a PC that does not have a Web server installed.
This approach allows students working in a lab to put e2glite.jar,
their knowledge base and Web page on a floppy disk that may be
moved among PCs. To run e2gLite in this mode,
you load the Web page that incorporates
the <APPLET> tags with a file address of the form:
Java appletviewer:
The Java appletviewer, included with the Java Development Kit (JDK),
is a program that lets you run an applet without using a browser or Web server.
You provide the appletviewer with the name and location
of a Web page that loads the applet and defines its parameters, and the
appletviewer pops up a window that runs the applet. To use this capability
you must install and configure the JDK on your PC. You may obtain the JDK
from the download area of the Sun Web site:
http://www.sun.com.
Instructions for configuring the JDK are included with the download.
Private Web server:
Installing a Web server on the computer
that you will use for developing your expert systems is strongly
recommended. A Web server allows you to test your knowledge bases,
see the overall design of a page in which e2gLite is embedded
and evaluate the impact of browser idiosyncracies on your content
more realistically than you will be able to by loading the page
that invokes e2gLite as a file or with the appletviewer.
You can acquire a Web server for PC operating systems at
no cost. For Windows 98/ME, Microsoft's Personal or
Peer Web Server (PWS) is available.
It is included on the Win 98 install CD in the "add ons" directory or
may be downloaded from the Microsoft Web site. Either PWS or the Internet
Information Server (IIS) is available as part of the install process for
recent versions of other Microsoft operating systems.
The Apache Web server is available
for many operating systems including Windows, Linux and other Unix variants.
(http://www.apache.com).
Public Access Web server: To share your knowledge with an expert
system, you will need your own
public Web site. If you don't already have a site, the first step is
to see if your Internet Service Provider (ISP) or school (if you're a
student) provides space on a Web server.
Check your ISP's home page and its customer
service links thoroughly, because information on the free home page
benefit isn't always obvious. If this approach doesn't help, free sites
are available from many other sources. Yahoo/GeoCities is one alternative.
There are also a number of Web sites that provide lists of
available free Web hosting. You can locate these with any search engine
(search for "free Web hosting"). Here's one example:
If you have an educational or other free Web site, the address will probably look more like this:
The demonstrations should run just as they did from the eXpertise2Go.com Web site when you worked through Module 1.
Once you have your Web site configured properly to run these examples, you are ready to start developing knowledge bases of your own and should proceed to Module 3 for an overview of expert systems technology and then to Module 4 to begin working with the e2gLite software.