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Chapter 3 Knowledge Representation. Knowledge Representation. Semantic Network Network Representation Conceptual Graph Frame. Semantic Network. Network Representation. Conceptual Graph. Conceptual Graph. Case Frame. Conceptual / Graph Frame : Hotel Bed. Frame : Hotel Bed.
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Knowledge Representation • Semantic Network • Network Representation • Conceptual Graph • Frame Chapter 3
Semantic Network Chapter 3
Network Representation Chapter 3
Conceptual Graph Chapter 3
Conceptual Graph Chapter 3
Case Frame Chapter 3
Conceptual / Graph Frame : Hotel Bed Chapter 3
Frame : Hotel Bed Chapter 3
Frame : Bird Chapter 3
Frame :Penguin 1 : Ambiguity Chapter 3
Frame :Penguin 2 : resolve ambiguity Chapter 3
Frame : Penguin 3 : Subclass relation Chapter 3
Knowledge Representation • important attribute : isa and instance • relationship among attributes • at what level of detail should the world be represented? • Mary is Sue’s cousin. เมรี่เป็นหลานของซู • Mary = daughter(brother(mother(Sue))) • Mary = daughter(sister(mother(Sue))) • Mary = daughter(brother(father(Sue))) • Mary = daughter(sister(father(Sue))) • Mary = daughter(sibling(parent(Sue))) Chapter 3
Knowledge Representation The End • John broke the window • Sequence ? pick up hard object , Hurl the object to the window • Cause hand / foot to move fast and crash into the window • Shut the window so hard that the glass breaks • Finding the right structure • John went to Sizzer last night. He ordered a large rare steak, paid his bill, and left. • Did john eat dinner last night? • John flew to New York. • John flew a kite. • John flew down the street. Chapter 3
Inheritable Knowledge The End Chapter 3
Frame Baseball-Player isa : Adult-Male bats: (EQUAL handed) height: 6-1 batting-average: .252 figure 4.7 Chapter 3
Procedural Knowledge as Rules The End similar to figure 4.7 Chapter 3
Redundant Representation The End John punched Mary Mary punched John Chapter 3
Similarity Net liking among set of frame The End Chapter 3
Representations The End man(Marcus) man(Caesar) person(Cleopatra) X : man(X) person(X) y person(y) y = Cleopatra y = Marcus y = Caesar Chapter 3
Matching The End 1. Indexing : problems: 1. need large number of rules 2. the precondition of rule is not always obvious 2. Matching with variables problems: many-many match problem many rules are matched against many elements in the state description simultaneously. son(X,Y) and son(Y,Z) :- grandson(X,Z) 3. Complex and approximate matching Chapter 3
Indexing The End Chapter 3
Logic Programming x : pet(x) small(x) apartment_pet(x) x : cat(x) dog(x) pet(x) x : poodle(x) dog(x) small(x) poodle(fluffy) A Representation in Logic The End apartment_pet (X) :- pet (X), small (X) . pet (X) :- cat (X) . pet (X) :- dog (X) . dog (X) :- poodle (X) . small (X) :- poodle (X) . poodle (fluffy) . A Representation in PROLOG Rules Fact Figure 6.1: Declarative and a Procedural Representation Chapter 3
Complex Indexing their precondition approximately match the current situation -> ELIZA Person: Men are all alike. ELIZA: In what way? Person: They’re always bugging us about something or other. ELIZA: Can you think of a specific example? Person: Well, my boyfriend made you come here. ELIZA: Your boyfriend made you come here. Person: He says I’m depressed much of the time. ELIZA: I am sorry to hear you depressed. Person: It’s true. I am unhappy. ELIZA: Do you think coming here will help you not to be unhappy? Person: I need some help, that much seems certain. ELIZA: What would it mean to you if you got some help? Person: Perhaps I could learn to get along with my mother. ELIZA Tell me more about your family. The End Figure 6.6: A Bit of a Dialogue with ELIZA Chapter 3
Complex Indexing The End (X me Y) (X you Y) (I remember X) (Why do remember X just now?) (My {family-member} is Y) (Who else in you family is Y?) (X {family-member} Y) (Tell me more about your family) Figure 6.7: Some ELIZA-like rules Chapter 3
Control Knowledge The End • Knowledge about which parts are most likely to find the goal state. • Knowledge about which rules to apply in a given situation. • Knowledge about the order in which to pursue subgoals. • Knowledge about useful sequence of rules to apply. 1. Long term memory -> Rules 2. Short term memory -> Working memory Chapter 3
Even if you're on the right track, you'll get run over if you just sat there.