PCjs Machines

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!

                                      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).

         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.

 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