KNOWLEDGE Represention

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Artificial Intelligence CS364Artificial Intelligence CS364

Knowledge and Expert SystemsKnowledge and Expert Systems

Lectures on Artificial Intelligence CS364Lectures on Artificial Intelligence CS364


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ContentsContents

* +at is Knowledge,

* +at is Knowledge Ac-(isition,

* .e Expert Systems /eelopment .eam&

* 1(les and Knowledge 1epresentation* 1(le2!ased Expert Systems&

* Caracteristics of Expert Systems&


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()at is Knowledge*()at is Knowledge*

* Knowledgeis a teoretical or practical (nderstanding of a

s(!ect or a domain& Knowledge is also te s(m of wat is

c(rrently nown5 and apparently nowledge is power&

* .ose wo possess nowledge are called experts&

* Anyone can !e considered a domain expert if e or se as

deep nowledge of !ot facts and r(les7 and strong

practical experience in a partic(lar domain& .e area of

te domain may !e limited&

* In general5 an expert is a silf(l person wo can do tings

oter people cannot&


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Ac+uiring KnowledgeAc+uiring Knowledge

* Knowledge ac-(isition can !e regarded as a metod !y

wic a 'nowledge engineergaters information mainly

from experts5 !(t also from text !oos5 tecnical man(als5

researc papers and oter a(toritatie so(rces for (ltimate

translation into a 'nowledge $ase5 (nderstanda!le !y !otmacines and (mans&

* .e person (ndertaing te nowledge ac-(isition5 te

nowledge engineer5 m(st conert te ac-(ired nowledge

into an electronic format tat a comp(ter program can (se&


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Ac+uiring KnowledgeAc+uiring Knowledge

* .e important caracteristics of nowledge are tat it is experiential5descriptie5 -(alitatie5 largely (ndoc(mented and constantlycanging&

* .ere are certain domains were all tese properties are fo(nd and

some were tere are only a few&

* .e lac of doc(mentation and te fact tat experts carry a lot ofinformation in teir eads5 maes it diffic(lt to gain access to teirnowledge for deeloping information systems in general and expert

systems in partic(lar&

* .erefore5 nowledge engineers ae deised specialised tecni-(esto extract and doc(ment tis information in an efficient and expedientmanner&


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C)aracteristics of Knowledge Ac+uisitionC)aracteristics of Knowledge Ac+uisition

* Knowledge ac-(isition is a la!o(r and time intensieprocess&

* C(rrently nowledge !ases for nowledge !ased systems

are crafted !y and5 tis is a seere limitation on te rapiddeployment of s(c systems&

* $iggest !ottlenec9 in system deelopment&

* :ost expensie part money5 time ; la!o(r7&

* A(tomating KA te (ltimate goal&


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B>S# and also some experience in te application of

different types of expert system sells&

* In addition5 te programmer so(ld now conentional

programming lang(ages lie aa5 C5 >ascal5 DB1.1A

and $asic&


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,ro.ect /anager,ro.ect /anager

* .e proect manager is te leader of te expert system

deelopment team5 responsi!le for eeping te proect on

trac&

* .e proect manager maes s(re tat all deliera!les and

milestones are met5 interacts wit te expert5 nowledge

engineer5 programmer and end2(ser&


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End01serEnd01ser

* .e end2(ser5 often called (st te (ser5 is a person wo

(ses te expert system wen it is deeloped&

* .e (ser m(st not only !e confident in te expert system

performance !(t also feel comforta!le (sing it&

* .erefore5 te design of te (ser interface of te expert

system is also ital for te proect9s s(ccessF te end2(ser9s

contri!(tion ere can !e cr(cial&


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Knowledge and 2ulesKnowledge and 2ules

* .e (man mental process is internal5 and it is too

complex to !e represented as an algoritm& Goweer5 most

experts are capa!le of expressing teir nowledge in te

form of rulesfor pro!lem soling&

ID te traffic ligt9 is green

.GE te action is go

ID te traffic ligt9 is red

.GE te action is stop


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2ules and Knowledge 2epresentation2ules and Knowledge 2epresentation

* .e term rulein AI5 wic is te most commonly (sed

type of nowledge representation5 can !e defined as an ID2

.GE str(ct(re tat relates gien information or facts in

te ID part to some action in te .GE part&

* A r(le proides some description of ow to sole a

pro!lem& 1(les are relatiely easy to create and

(nderstand&

* Any r(le consists of two parts=

te ID part5 called te antecedentpremiseor condition7

and te .GE part called te conse+uentconclusionor action7&


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2ules and Knowledge 2epresentation2ules and Knowledge 2epresentation

* A r(le can ae m(ltiple antecedents oined !y te

eywords A/ con(nction75 B1 dis(nction7 or a

com!ination of !ot&

ID Hantecedent @ ID Hantecedent @

A/ Hantecedent " B1 Hantecedent "

" "

" "

" "A/ Hantecedent n B1 Hantecedent n

.GE Hconse-(ent .GE Hconse-(ent

A ifi i l lli CS364


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KNOWLEDGE Represention