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Information about “ESIE”
Put some smarts in your personal computer and turn it into your very own
assistant. ESIE, the Expert System Inference Engine, is an artificial
intelligence shell that lets you build a custom knowledge base, or
expert system, to help you make decisions.
Simple but effective, ESIE operates by loading in a knowledge base and
building inferences out of the rules contained therein. You define the
rules that the system uses. This is especially good as an introduction
to expert systems as well as having excellent on-disk documentation to
get you started in AI. For the advanced student, ESIE can handle the
normal gamut of expert systems building.
To see how ESIE works without building your own knowledge base, load
ESIE and one of the three supplied knowledge bases (ANIMAL, DOCTOR, or
GLASS) and try it!
ABOARD.DOC
ESIE
The Expert System Inference Engine
Manual For the ABOARD Knowledge Base
Lightwave July 1986
P.O. Box 16858
Tampa, FL 33617
Copyright 1986
All Rights Reserved.
This manual may only be distributed as one file on the ESIE
distribution diskette. Such duplication and distribution is
authorized without compensation as long as the diskette is a
duplicate of the ESIE distribution diskette. This manual may
also be distributed in printed form as long as a copy of the
distribution diskette is attached. All other distribution is
strictly prohibited.
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The following documentation was written by one our users.
This documentation is intended to accompany the ABOARD
knowledge base.
All names and addresses have been removed to protect the
innocent.
Lightwave takes no responsibility for the accuracy of the
contents, but we offer our sincere thanks to the user who
submitted this material. He is receiving a complimentary
upgrade to ESIE 2.0 for his troubles.
To Get Abaord
An Expert System Shell
and Knowledge Base
Introduction.
This project was done in fulfillment of the requirements for
Decision Support Systems, Naval Postgraduate School,
Monterey.
Part 1. Application.
The military application that this expert system is designed
to meet is the circumstance where a Coast Guard cutter
arrives alongside another vessel at sea and wishes to conduct
a boarding. The legal grounds on which to base a boarding
are scattered through several laws and treaties. Knowledge
of this material is an expert application.
Coast Guard commanding officers, operations officers and
boarding officers are usually familiar with this material,
but other people assisting us frequently are not. This
system is designed to provide some assistance. For instance,
Coast Guard boarding teams are now riding Navy ships. Navy
personnel are generally unfamiliar with the law enforcement
mission details, yet a Navy CO is required to support that
boarding party. This system can function as a training aid
or intelligent checklist for him.
A little mare nostrum.
The law is made up of a few generalizations and thousands of
exceptions. The two generalizations considered here are:
1) Vessels of a flag state on the high seas are subject to
the jurisdiction of that state and no other.
2) Vessels within the jurisdictional waters of a state are
subject to that state's jurisdiction.
The exceptions are coded into the knowledge base. These
exceptions are found in a number of places:
The Constitution, particularly the Bill of Rights,
Treaties and conventions with other countries, US laws
(found in the US Code -- USC), Coast Guard and State
Department policies, Presidential orders.
For the operator.
Scenario. You are a Commanding Officer, or Operations
Officer of a vessel carrying a Coast Guard boarding officer
(not necessarily a Coast Guard cutter -- the boarding
authority goes with the people, not the cutter). You have
just driven up alongside a vessel 'out there'. You want to
get the boarding officer aboard that vessel and need a legal
basis. This knowledge base asks pertinent questions directed
at gaining that basis.
To run. From the MSDOS prompt:
>esie <cr>
filename for knowledge base: aboard <cr>
==>go <cr>
answer questions yes or no followed by <cr>
Things are error trapped, so typing mistakes are no problem.
If the scenario changes, rerun the program from the top.
WARNING. This knowledge base assumes that the user is a
Coast Guard boarding officer (or his supervisor). No one
else anywhere has the same combination of law enforcement
jurisdiction, so any other user could easily be overstepping
his authority.
For instance, if a vessel is inside the US Fishery
Conservation Zone and is a fishing vessel, Coast Guard
boarding officers and National Marine Fisheries agents both
have jurisdiction. But Customs officers do not. Similarly,
if a vessel is operating in the Contiguous Zone, and not
fishing, then the jurisdiction falls to Coast Guard boarding
officers and Customs officers -- but not to NMFS agents.
Other military agencies are prohibited from direct exercise
of law enforcement authority by the Posse Comatatus Act and
do not have any of this authority.
Part 2. The shell.
This knowledge base was built to run on ESIE, an Expert
System Inference Engine. ESIE, in turn, runs under MSDOS and
is available from Lightwave. ESIE is a 'shareware' variant
of public domain. As explained in the documentation, the
program is released to the public domain. For $145, full
support including the source code is furnished.
For definitions, see the MANUAL file on the ESIE disk.
The single GOAL allowed is 'board.reason'. When the
knowledge base is able to reach a conclusion, the
'board.reason' goal has been satisfied. The ANSWER clause at
the end of the file acts to print it out.
The second line in the file (after the GOAL) is LEGALANSWERS.
For this knowledge base, the only legal answers are 'yes' and
'no'. (Answers are case insensitive and illegal answers are
all harmlessly trapped.)
Following the LEGALANSWERS clause are a series of IF...THEN
rules. Order is of note. The first IF...THEN clause is
attempted to be satisfied. All the questions within the
clause are tracked in a backward chain fashion (which may be
directly through the question clauses or indirectly through
other IF...THEN clauses). If the GOAL remains unsatisfied at
this point, then ESIE falls through and considers the next
IF...THEN statement.
For this reason, the statement about requesting the master's
permission and being denied is last. You want to exhaust the
other alternatives first and you don't want the system to
give up in disgust until you have tried everything else.
In a few cases (like government vessels) a quick conclusion
can be reached. In that case, board.reason is satisfied and
the session terminates. The system is designed to be
persistent -- unless a definite reason not to board is
arrived at, the system will grasp at virtually any reason to
get aboard (which is how seizures are made...)
Following the IF...THEN clauses are the QUESTION statements.
These inqure of data from the operator in order to satisfy
the IF...THEN clauses. QUESTIONS are only asked as the
result of IF...THEN clauses needing data.
The final statement is the aforementioned ANSWER clause.
Limitations. ESIE has no capability for handling
uncertainty. That is not required for this application.
Systems involving more judgement than boarding legalities
would be found short.
ESIE is implemented under MSDOS; the Coast Guard is buying a
'standard terminal' that runs CTOS which is not compatible
(despite the same 8088/8086 under the hood). To implement
the system for Coast Guard use, the source code would have to
be recompiled under the CTOS Pascal compiler. However, once
that is done, the knowledge base itself should run without
changes.
This application does not need it, but ESIE provides no
alternative to keyboarding input. If the database changes,
the program must be rerun to reflect those changes.
Part 3. Implementation. [Code is attached.]
Part 4. Diary.
The initial work was done in February 1986. After printing
out the ESIE documentation and idly chewing on it for a
couple weeks, I spent about 4 hours assembling an initial
working program. I functioned as the expert as well as the
knowledge engineer. The knowledge base then worked using my
knowledge which is about two years rusty.
A day or so later, another person worked through the program
and suggested several cosmetic and a few substantive changes,
again on his memory knowledge. This update took an hour,
including his time.
Second stage, late Feb 86. Obtained a copy of the Coast
Guard's Maritime Law Enforcement Manual. This allowed me to
make some minor corrections to some existing rules, and to
add several rules that pertain to the more obscure exceptions
(try getting aboard a Japanese salmon boat outside the US FCZ
-- it can be done.) The diminishing marginal returns are very
obvious -- lots of rules gain minimal production. But the
detailed exceptions are frequently where the big cases are
made. 3 more hours.
Final work. Early in March, I had mulled over what I had and
wanted to get in some improvements. Particularly, I wanted
to avoid asking the user about Pacific specific conventions
if he was operating in the Atlantic. So those area-specific
convention rules were updated.
Part 5. Benchmarking.
Since input is keyboarded rather than drawn from a database
on disc, it is not practical to benchmark in the traditional
sense (stopwatch). The processing appears prompt to the
user, even on a slow 8088. Consequently, there is no real
incentive to recode the program more conventionally. Indeed,
that would limit its maintainability.
Loading and compilation of the knowledge base takes about 30
seconds from the > operating system prompt using a 4.77mHz
CPU.
Intuition to the contrary, a considerable evolutionary change
has occurred over the body of law that this application
covers. Examples include the case of US vs Piner which
limited boarding authority in the 9th Circuit for about 4
years, until a related case was heard by the Supreme Court
and resolved. Similarly, the Fisheries Conservation and
Management Act, and its special jurisdiction, is now ten
years old.
Since the Coast Guard is chronically too tight-fisted to hire
a programmer to maintain an application like this, leaving
the system in a higher level, maintainable, construction
makes sense.
Part 6. Lessons.
The first lesson is that I was lucky. The application and
the shell were very well matched to each other. Most of the
things this shell lacks are features that the application
doesn't need. Probably the one desired feature is the
ability to chain to another file and display it.
The surprise to me was the small number of rules (about 30)
necessary to manage a complex problem. I expected a lot more
rules to be required when I started.
The existing system runs in 128K of memory, which appears
minimal to handle an exhaustive set of rules for this
application. If the reference material were on disc, the
shortcoming could be in disc space, not RAM. Since the
author will provide the source code for $145, it would be
quite practical to recompile the code for a larger memory
space which would enlarge the stack space and push back the
limitations.
The system can be expected to run as fast as an operator can
type in data. The only shortcoming here is that data cannot
be edited once it is entered (e.g. as circumstances change).
CHECK.TXT
You can test your copy of the distribution diskette, to make
sure the copy is accurate, by entering the command CHECK *.*
at the DOS prompt. The output should look like this:
CRCK ver 4.2B (MS DOS VERSION )
CTL-S pauses, CTL-C aborts
--> FILE: READ .ME CRC = 89 EB
--> FILE: ESIE .COM CRC = 70 F3
--> FILE: CONFIG .COM CRC = 71 16
--> FILE: MANUAL . CRC = 56 1A
--> FILE: TUTOR . CRC = B1 C9
--> FILE: NOVICE . CRC = 63 D7
--> FILE: HISTORY . CRC = DD 31
--> FILE: FINAL .USE CRC = B7 3F
--> FILE: ANIMAL . CRC = 6B A8
--> FILE: DOCTOR . CRC = 4C 3E
--> FILE: GLASS . CRC = A0 08
--> FILE: ABOARD . CRC = 9B FC
--> FILE: ABOARD .DOC CRC = AE 02
--> FILE: GETAWAY . CRC = 7C 82
--> FILE: HEIGHT . CRC = FC C9
--> FILE: HAIR . CRC = 99 4A
--> FILE: SUPPORT . CRC = 06 72
--> FILE: CHECK .COM CRC = BD 22
--> FILE: CHECK .TXT CRC = 00 00
---------------------> SUM OF CRCS = E4 33
DONE
Note: the CRC for CHECK.TXT will be incorrect as will be the
total, because you cannot write a file's CRC to the file
without altering the CRC of the file.
Directory of PC-SIG Library Disk #0398
Volume in drive A has no label
Directory of A:\
ABOARD 8783 7-02-86 12:20a
ABOARD DOC 13810 7-06-86 6:42a
ANIMAL 9872 7-05-86 10:12a
CHECK COM 1536 10-21-82 5:50p
CHECK TXT 1432 7-06-86 8:02a
CONFIG COM 14363 7-06-86 12:05a
DOCTOR 6403 8-22-85 1:51a
ESIE COM 24028 7-04-86 10:23a
FINAL USE 11159 7-06-86 7:50a
GETAWAY 1519 7-05-86 10:03a
GLASS 5748 7-14-85 12:55a
HAIR 402 7-02-86 2:54a
HEIGHT 719 7-05-86 10:00a
HISTORY 26033 7-06-86 7:50a
MANUAL 61626 7-06-86 7:37a
NOVICE 13665 7-06-86 7:50a
READ ME 1816 7-05-86 9:10a
SUPPORT 2082 7-05-86 8:57a
TUTOR 60767 7-06-86 7:42a
19 file(s) 265763 bytes
46080 bytes free