CS代考计算机代写 PowerPoint Presentation

PowerPoint Presentation

Classification

Learning by Recording Cases
Incremental Concept Learning
Version Spaces
Classification
Learning

Lesson Preview

Learning concepts

Equivalence classes

Concept hierarchies

Types of concepts

Bottom-up search

Which of these are birds?







Image credits:
Carl Chapman, http://www.flickr.com/photos/12138336@N02/1997128094/
Elaine Wilson, http://www.naturespicsonline.com/Nature15/
Nicor, https://commons.wikimedia.org/wiki/User:Nicor
Samuel Blanc, http://www.sblanc.com/
Urville Djasim, https://secure.flickr.com/photos/urville_djasim/3611889680/
Daniel Vianna, https://commons.wikimedia.org/wiki/User:Mr.Rocks
Alessandro Di Grazia, http://www.petsugargliders.eu/
Jaroslav Novák, https://commons.wikimedia.org/wiki/File:Duck_Hen.jpg
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Has wings?
Has feathers?
Has talons?
Has a beak?
Flies?
Runs?
Lays eggs?
Carnivorous?
Vegetarian?
Blue?
Red?
Swims?
Builds nests?

Cognitive System
Reaction
Deliberation
Metacognition
Reasoning
Learning
Memory
Input
Output

Input
Output
Cognitive System

Has wings?
Has feathers?
Has talons?
Has a beak?
Flies?
Runs?
Lays eggs?
Carnivorous?
Vegetarian?


2m actions

Input
Output
Cognitive System
2n percepts

2m actions

Input
Output
Cognitive System
10 percepts = 1024 combinations
100 percepts = 1.2 × 1030 combinations
= 1.2 nonillion combinations
300 percepts = 2.0 × 1090 combinations
= more combinations than atoms in the universe

Input
Output
Cognitive System
2n percepts

2m actions

Input
Output
Cognitive System
2n percepts
→ k concepts →
2m actions

Input
Output
Cognitive System
2n percepts
→ k concepts →
2m actions
“Equivalence Classes”

Eagle Bluebird Penguin
Lays eggs?
ο Yes ο No ο Maybe
Has wings?
ο Yes ο No ο Maybe
Has talons?
ο Yes ο No ο Maybe
Flies?
ο Yes ο No ο Maybe
Has fur?
ο Yes ο No ο Maybe
Large?
ο Yes ο No ο Maybe Lays eggs?
ο Yes ο No ο Maybe
Has wings?
ο Yes ο No ο Maybe
Has talons?
ο Yes ο No ο Maybe
Flies?
ο Yes ο No ο Maybe
Has fur?
ο Yes ο No ο Maybe
Large?
ο Yes ο No ο Maybe Lays eggs?
ο Yes ο No ο Maybe
Has wings?
ο Yes ο No ο Maybe
Has talons?
ο Yes ο No ο Maybe
Flies?
ο Yes ο No ο Maybe
Has fur?
ο Yes ο No ο Maybe
Large?
ο Yes ο No ο Maybe

For each of these three animals, choose the value for each percept that applies to that animal.

Block
Brick
Wedge
is-a
is-a

Vertebrate
Bird
Reptile
Mammal
Bluebird
Penguin
Eagle

Bird
Lays eggs?
ο Yes ο No ο Maybe
Has wings?
ο Yes ο No ο Maybe Has talons?
ο Yes ο No ο Maybe
Flies?
ο Yes ο No ο Maybe Has fur?
ο Yes ο No ο Maybe
Large?
ο Yes ο No ο Maybe

How would you characterize the class ‘bird’ given the characterization of its subclasses below?
Eagle Bluebird Penguin
Lays eggs? Yes
Has wings? Yes
Has talons? Yes
Flies? Yes
Has fur? No
Large? Yes Lays eggs? Yes
Has wings? Yes
Has talons? Yes
Flies? Yes
Has fur? No
Large? No Lays eggs? Yes
Has wings? Yes
Has talons? No
Flies? No
Has fur? No
Large? Yes

More formal
Less formal
Axiomatic concepts
Prototype concepts
Exemplar concepts

Axiomatic concepts:
Concepts defined by a formal set of necessary and sufficient conditions.

Example: a circle

Axiomatic concepts:
Concepts defined by a formal set of necessary and sufficient conditions.

Circle: all points in a plane that are equidistant from a single point.

Prototype concepts:
Base concepts defined by a typical example with overridable properties.

Example: a chair

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Prototype concepts:
Base concepts defined by a typical example with overridable properties.
Chair
#-of-legs : four material : metal
has-back : true
has-arms : false
is-cushioned : false

Prototype concepts:
Base concepts defined by a typical example with overridable properties.
Chair
#-of-legs : four
material : metal
has-back : true
has-arms : false
is-cushioned : false

Stool
has-back : false

Folding chair
has-back : true
#-of-legs : four
has-arms : false

Exemplar concepts:
Concepts defined by implicit abstractions of instances, or exemplars, of the concept.

Example: beauty

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Exemplar concepts:
Concepts defined by implicit abstractions of instances, or exemplars, of the concept.

Image credit:
DNGDesign, http://dngdesign.deviantart.com/art/Sunset-361106086
scillystuff, http://www.flickr.com/people/55296256@N00
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More formal
Less formal
Axiomatic concepts
Prototype concepts
Exemplar concepts

More formal
Less formal
Rank the following concepts based on their formality:
Inspirational
Reptile
Foo
Right Triangle
Holiday
Saltiness
4. Right Triangle
2. Reptile
3. Foo
5. Holiday
1. Inspirational
6. Saltiness

Vertebrate
Bird
Reptile
Mammal
Bluebird
Penguin
Eagle

GDP
Future of
Dow Jones
Industrial
Average
Inflation
Employment
Overtime
Hours
New
Orders
Index
Consumer
Sentiment
Index
Jobless
Claims
Commodity
Futures
Index
NASM
ISM
PMI
GDP
3/4ths
Age
Job
Vacancies
Actual
Hours
Worked

Assignment

How would you use classification to design an agent that could answer Raven’s progressive matrices?

To recap…

Concept learning

Equivalence classes

Concept hierarchies

Axiomatic, prototypical, and exemplar concepts

Bottom-up search

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