Artificial Intelligence

15-381: Artificial Intelligence

Introduction and Overview

Course data

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All up-to-date info is on the course web page:

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http://www.cs.cmu.edu/afs/cs.cmu.edu/academic/class/15381-s07/www/

Instructors:

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Martial Hebert

Mike Lewicki

TAs:

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Rebecca Hutchinson

Gil Jones

Ellie Lin

Einat Minkov

Arthur Tu

See web page for contact info, office hours, etc.

Intelligence

What is “intelligence” ?

Can we emulate intelligent behavior in machines ?

How far can we take it ?

Brains vs computers

Brains (adult cortex)

Computers (Intel Core 2)

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surface area: 2500 cm2

squishy

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surface area: 90 mm2

crystalline

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neurons: 20 billion

synapses: 240 trillion

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transistors: 291 million

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neuron size: 15 um

synapse size: 1 um

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transistor size: 65 nm

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synaptic OPS: 30 trillion

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FLOPS: 25 billion

Deep Blue: 512

processors, 1 TFLOP

Intelligent systems

Three key steps of a knowledge-based

agent (Craik, 1943):

1. the stimulus must be translated into an

internal representation

2. the representation is manipulated by

cognitive processes to derive new

internal representations

3. these in turn are translated into action

“agent”

perception

cognition

action

Representation

All AI problems require some form of representation.

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chess board

maze

text

object

room

sound

visual scene

perception

cognition

action

A major part AI is representing the problem space so

as to allow efficient search for the best solution(s).

Sometimes the representation is the output.

E.g., discovering “patterns”.

Output

The output action can also be complex.

perception

cognition

action

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next move

text

label

actuator

movement

From a simple chess move to a motor

sequence to grasp an object.

Russel and Norvig question 1.8

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Is AI’s traditional focus on higher-level cognitive...