Expert System

Group Members:Group Members:

Nabeel Hussain (SP07-BB-0006)Nabeel Hussain (SP07-BB-0006)

Syed Owais Ali (SP07-BB-0135)Syed Owais Ali (SP07-BB-0135)

Present to; Present to;

Respected Sir Respected Sir Manoj KumarManoj Kumar

Presentation Topic

AgendaAgenda DefinitionsDefinitions Expert System ConceptExpert System Concept Expert System ComponentsExpert System Components Expert System TasksExpert System Tasks Expert System DomainExpert System Domain Expert System CharacteristicsExpert System Characteristics Advantages of Expert SystemsAdvantages of Expert Systems History and ExamplesHistory and Examples SummarySummary

A knowledge-based system is a program whose performance depends more on the explicit presence of a large body of

knowledge than on the possession of ingenious computational procedures.

An Expert System is a KBS whose performance is intended to rival that of human experts.

I.e., an expert system achieves expert level performance,

while being highly domain specific.

Knowledge-based SystemsKnowledge-based Systems

How ES differ form other AI How ES differ form other AI

Subject matter of realistic complexity that Subject matter of realistic complexity that normally requires a considerable amount normally requires a considerable amount of human expertise.of human expertise.

High performance in terms of speed and High performance in terms of speed and reliability is needed.reliability is needed.

Must be capable of explaining and Must be capable of explaining and justifying solutions or recommendations.justifying solutions or recommendations.

Expert System Definition Expert System Definition

An expert system is a computer program that An expert system is a computer program that representsrepresents and and reasonsreasons with with knowledgeknowledge of some of some specialistspecialist subject with a view to subject with a view to solving problemssolving problems or or giving advicegiving advice..

Possess knowledge Possess knowledge

Specific domainSpecific domain

Solving problem or giving adviceSolving problem or giving advice

Basic Expert System Concepts Basic Expert System Concepts

Knowledge baseKnowledge base Inference engineInference engine Facts Facts ExpertiseExpertise Problem domainProblem domain Knowledge domain of the expertKnowledge domain of the expert

Expert System components Expert System components

User interfaceUser interface

Explanation facilityExplanation facility- - explains reasoning of the explains reasoning of the system to a usersystem to a user

Knowledge Base – Knowledge Base – production memory (rules)production memory (rules)

Working memoryWorking memory- - global database of factsglobal database of facts

Inference engineInference engine

AgendaAgenda- - prioritized list of rules satisfied by factsprioritized list of rules satisfied by facts

Knowledge acquisition facilityKnowledge acquisition facility

Expert System Tasks Expert System Tasks

The interpretation of dataThe interpretation of data Diagnosis of malfunctionsDiagnosis of malfunctions Structural analysis of complex objectsStructural analysis of complex objects Configuration of complex objectsConfiguration of complex objects Planning sequences of actions Planning sequences of actions

Engineering Motivations

Faster

Reliable

Cheaper

Institutionalized memory

E.g., HP micro-fabrication system

Less training

Expert Systems Domains Expert Systems Domains

Medical and health applicationsMedical and health applications Agricultural, Livestock, and food issues Agricultural, Livestock, and food issues

and needsand needs Energy OptionsEnergy Options Natural Resource ExploitationNatural Resource Exploitation Space TechnologySpace Technology

Expert System Characteristics Expert System Characteristics

Simulates human reasoning about a Simulates human reasoning about a problem domainproblem domain

Performs reasoning over representations Performs reasoning over representations of human knowledge.of human knowledge.

Solves problems by heuristic or Solves problems by heuristic or approximate methods.approximate methods.

Advantages of Expert systems Advantages of Expert systems

Increased availabilityIncreased availabilityReduced costReduced costReduced dangerReduced dangerPermanencePermanenceMultiple expertiseMultiple expertiseIncreased reliabilityIncreased reliabilityExplanationExplanationFast response; steady, unemotional complete Fast response; steady, unemotional complete response at all times; response at all times; Intelligent tutor, Intelligent databaseIntelligent tutor, Intelligent database

Early Expert System

DENDRAL (’68, Feigenbaum,Buchanan, Letter berg)’first expert system

analyzed NMR mass spectrogram data to determine the geometric arrangement of atoms in a molecule.

It is (was?) in routine use by chemists, and has contributed to refereed journal publications.

Different Expert SystemsDifferent Expert SystemsAgricultural Expert systemsAgricultural Expert systems Rice-Crop Doctor Rice-Crop Doctor National Institute of Agricultural Extension Management (MANAGE) National Institute of Agricultural Extension Management (MANAGE)

has developed an expert system to diagnose pests and diseases for has developed an expert system to diagnose pests and diseases for rice crop and suggest preventive/curative measures. The rice crop rice crop and suggest preventive/curative measures. The rice crop doctor illustrates the use of expert-systems.doctor illustrates the use of expert-systems.

Farm Advisory SystemFarm Advisory SystemPunjab Agricultural University, Ludhiana, has developed the Farm Punjab Agricultural University, Ludhiana, has developed the Farm

Advisory System to support agri-business management. The Advisory System to support agri-business management. The conversation between the system and the user is arranged in such a conversation between the system and the user is arranged in such a way that the system asks all the questions from user one by one way that the system asks all the questions from user one by one which it needs to give recommendations on the topic of farm which it needs to give recommendations on the topic of farm Management.Management.

Different Expert SystemsDifferent Expert SystemsMedical Expert SystemMedical Expert SystemHELPHELPThe HELP (Health Evaluation through Logical Processes) System is a The HELP (Health Evaluation through Logical Processes) System is a

complete knowledge based hospital information system. It supports complete knowledge based hospital information system. It supports not only the routine application of an HIS including ADT, order not only the routine application of an HIS including ADT, order entry/charge capture, pharmacy, radiology, nursing documentation, entry/charge capture, pharmacy, radiology, nursing documentation, ICU monitoring, but also supports a robust decision support ICU monitoring, but also supports a robust decision support function.function.The HELP system is an example of this type of knowledge-based The HELP system is an example of this type of knowledge-based hospital information system.hospital information system.

PEIRSPEIRS

(Pathology Expert Interpretative Reporting System) appends (Pathology Expert Interpretative Reporting System) appends interpretative comments to chemical pathology reports (Edwards et interpretative comments to chemical pathology reports (Edwards et al., 1993).al., 1993).

The knowledge acquisition strategy is the Ripple Down Rules method, The knowledge acquisition strategy is the Ripple Down Rules method, which has allowed a pathologist to build over 2300 rules without which has allowed a pathologist to build over 2300 rules without knowledge engineering or programming support.. PEIRS knowledge engineering or programming support.. PEIRS commented on about 100 reports/day. Domains covered include commented on about 100 reports/day. Domains covered include thyroid function tests, arterial blood gases, glucose tolerance tests, thyroid function tests, arterial blood gases, glucose tolerance tests, hCG, catecholamine and a range of other hormones.hCG, catecholamine and a range of other hormones.

Summary

Expert Systems solved practical problems with applications of logic based Techniques.

However, handling certainty was generally given short shrift.

There were successes in many areas.

Expert System help to make the work easier than everbefore.