EXPERT SYSTEMS or KNOWLEDGE BASED SYSTEMS

a. When we wish to encode a rich source of knowledge within the program. and b. The scope of systems knowledge is well defined. An expert system could be defined as a program designed to model the problem solving ability of a human expert. It is a clone to the expert of real life.

An expert needs - KNOWLEDGESpecialized knowledge on problem areas. Facts, rules, concepts and relationships. To store this in a KNOWLEDGE BASE, you need to learn KNOWLEDGE REPRESENTATION. REASONINGHow to reason with this knowledge. Knowledge processor also called INFERENCE ENGINE. You need to learn inferencing techniques.

WHY EXPERT SYSTEMS & NOT EXPERTS  Always available  Available anywhere  Replaceable  Non perishable  Consistent in performance  Work at a uniform speed  Affordable cost

These can be designed as replacement to an expert  When a human being exists with that knowledge  There is a client who needs their expertise  This expertise is not available  A software specialist to program this expertise

These can be for assisting an expert  Information recall  Improve productivity  Manage the complexities

USAGE-AREAS As per a survey, the ES were found to be in :(**-Max, *-Next Max)  Agriculture**  Law  Business  Manufacturing**  Chemistry  Mathematics  Communications  Medicine**  Computer Systems*  Meteorology  Education  Military*  Electronics*  Mining  Engineering*  Power Systems*  Environment*  Sciences  Geology  Space Technology*  Image Processing  Transportation  Information Management

USAGE-PURPOSES CONTROLVM monitors a patient in an intensive care unit and controls the treatment DESIGNPEACE is an expert system developed to assist engineers in the design of an electronic circuit DIAGNOSISNEAT infers system malfunctioning of data processing and telecommunications network equipment INSTRUCTIONGUIDON instructs medical students on antimicrobial therapy for bacterial infections INTERPRETATIONFXAA Provides auditing assistance in foreign exchange trading locating irregular transactions MONITORINGNAVEX monitors radar data and estimates the velocity and position of the space shuttle

USAGE-PURPOSES PLANNINGPLANPOWER provides a wide range of financial plans for households in the areas of cash management PREDICTIONPLANT predicts the damage to corn caused by the invasion of black cutworms PRESCRIPTIONBLUE BOX recommends an appropriate therapy for patients suffering from depression SELECTIONIREX assists in the selection of industrial robots in a work environment. It identifies the best choice from a list of possibilities SIMULATIONSTEAMER simulates and explains the operation of the Navy’s 1078-class frigate system propulsion plant to aspiring NAVAL engineers

EXPERT SYSTEM DEVELOPMENT MEDIUM 1970s:LISP, PROLOG and OPS 1980s :Expert System Shells (PC Based) A shell is a programming environment that contains all of the necessary utilities for both developing and running an expert system. Other programming languages can also be used. All these can be on : PCs/Workstations/Minis/Mains Largest number of shells is available on PCs today.

BASIC CONCEPTS OF EXPERT SYSTEMS  EXPERTISE : Expertise includes:  Facts about the problem area  Theories about the problem area  Hard-n-fast rules & procedures  Rules of what to do in a problem situation  EXPERTS : To mimic a human expert, it is necessary to build a system that exhibits a capability to: Recognize and formulate the problem Solve the problem quickly Explain the solution Learn from experience Restructure knowledge Break rules Determine relevance

BASIC CONCEPTS OF EXPERT SYSTEMS  TRANSFERING EXPERTISE : The objective of an ES is to transfer expertise from the expert to the computer and then on to other humans. This includes: Knowledge acquisition (from experts) Knowledge representation (in the computer)  In the knowledge base, you may have : Facts Procedures

BASIC CONCEPTS OF EXPERT SYSTEMS  REASONING : From knowledge base, the ES is programmed to make INFERENCES. The reasoning is performed in a component called INFERENCE ENGINE which includes procedures regarding problem solving by an approach called SYMBOLIC REASONING.  EXPLANATION CAPABILITY : ES has the ability to explain its advice or recommendations and even to justify why a certain action was not recommended.

HUMAN ELEMENT IN EXPERT SYSTEMS  THE EXPERT Also called DOMAIN EXPERT, a person possesses some special knowledge, judgement, experience and methods.  THE KNOWLEDGE ENGINEER: The person who helps the human experts structure the problem area by : Interpreting Integrating human answers to questions Drawing analogies Posing counter examples Highlighting conceptual difficulties

HUMAN ELEMENT IN EXPERT SYSTEMS  THE USER Person may be using an ES as a : Consultant – one who seeks advice Instructor - one who wants to learn Partner - one who wants to improve KB Colleague - one who is an expert

STRUCTURE OF AN EXPERT SYSTEM CONSULTATIONDEVELOPMENT

User Interface Recommended Action Explanation Inference Engine, Draws Conclusions KNOWLEDGE BASE FACTS: What is known about the problem area Rules: Logical Reference (Relation between Symptoms and Causes) Knowledge Engineer Expert Blackboard (Workplace) Plan: Agenda Solution: Problem Description Reasoning Capability Improvement KA Facts about the specific incident USER