1 Pertemuan 5 Knowledge Representation Issues Matakuliah: T0264/Inteligensia Semu Tahun: 2005 Versi:...
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Transcript of 1 Pertemuan 5 Knowledge Representation Issues Matakuliah: T0264/Inteligensia Semu Tahun: 2005 Versi:...
1
Pertemuan 5 Knowledge Representation Issues
Matakuliah : T0264/Inteligensia Semu
Tahun : 2005
Versi : 1/0
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Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• << TIK-99 >>
• << TIK-99>>
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4.2 Approaches to Knowledge Representation
Properties of a Representation System
• Representation adequacy• Inferential adequacy• Inferential efficiency• Acquisitional efficiency
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Viewing a Node as a Frame
Baseball-Player
Isa : Adult-Male
bats :(EQUAL handed)
height : 6-1
batting-average : .252
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4.3 Issues in Knowledge Representation
• Are there any basic attributes of objects ?• Are there any basic relationship among objects ?• At what level should knowledge be represented ?• How should sets be representation ?• How should knowledge be accessed ?
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4.3.2 Relationships among Attributes
Representing Inverses
• Reversible representations that ignore focus : Team(Pee-Wee- Reese, Brooklyn-Dodgers)
• Pairs of focused entities :- one associated with Pee Wee Reese :
team = Brooklyn-Dodgers- one associated with Brooklyn Dodgers :
team-members = Pee-Wee-Reese,...
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4.3.3 Choosing the Granularity of Representation
Suppose we are interested in the following fact :John spotted Sue.
We could represent this asspotted(agent(John),object(Sue))
Questions :Who spotted Sue ?Did John see Sue ?
We could add facts, e.g.:spotted(x,y) saw(x,y)
An alternative representation : saw(agent(John),object(Sue),timespan(briefly))
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Are There Primitive Concepts ?
Marry is Sue ‘s cousin.
• Marry = daughter(brother(mother(Sue)))• Marry = daughter(sister(mother(Sue))) • Marry = daughter(brother(father(Sue)))• Marry = daughter(sister(father(Sue)))
An alternative :• Marry = child(sibling(parent(Sue)))
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4.3.4 Representing Sets of Objects
Intensional and Extensional Representation
Extensional :
{Earth}
Intensional :{x : sun-planet(x) human-inhabited(x)}{x : sun-planet(x) nth-farthest-from-sun(x,3)}{x : sun-planet(x) nth-biggest(x,5) }
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4.3.5 Finding the Right Structures as Needed
Selecting an Initial Structure• Index structures by English words
- John flew to New York. He rode in a plane from one place to another.
- John flew a kite. * He held a kite that was up in the air.- John flew down the street.
* He moved very rapidly.- John flew into a rage. An idiom
• Index structures by concepts• Use one major clue
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4.4 The Frame Problem
A Similarity Net
CHAIR
TABLE STOOL
DESK SIDEBOARD
too big, no back
BENCH
no back,too wide
too high, no back
no knee room
drawers