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Artificial Intelligence:Definition

School of Computer Science & EngineeringChung-Ang University

Daewon Kim

Lecture Notes

What are AI Systems?

Deep Blue defeated the world chess champion Garry Kasparov in 1997

During the 1991 Gulf War, US forces deployed an AI logistics planning and scheduling program that involved up to 50,000 vehicles, cargo, and people

Proverb solves crossword puzzles better than most humans

Sony’s AIBO and Honda’s ASIMO

Web Agents & Search engines: Google, Yahoo

Recognition Systems: Speech, Character, Face, Iris, Fingerprint

Virtual Reality and Computer Vision

Some researchers consider AI as one of the four concepts:

1. Systems that think like humans

2. Systems that think rationally

3. Systems that act like humans

4. Systems that act rationally

AI: Acting humanly

Turing (1950): “The Turing Test”

Can machines think?

Can machines behave intelligently?

Turing test is The Imitation Game

Predicted that by 2000, a machine might have 30% chance of fooling a lay person for 5 min.

Problem: Turing test is NOT …

Turing test is NOT reproducible and amendable to mathematical analysis

AI: Thinking humanly

It requires scientific theories of internal activities of the brain

What level of abstraction? “Knowledge” or “circuits”.

How to validate? Requires something

Requires: Cognitive Science

Predicting and testing behavior of human subjects (top-down)

Requires: Cognitive Neuroscience

Direct identification from neurological data (bottom up)

Problem: Thinking humanly is NOT

Both are distinct from AI

The available theories do not explain anything resembling human-level general intelligence.

AI: Thinking rationally

Laws of Thought: “What are correct arguments/thought processes?” by Aristotle

Several Greek schools developed various forms of logic:

Logic: notation and rules of derivation of thoughts

Problem: Thinking rationally is NOT

Not all intelligent behavior is mediated by logical deliberation

AI: Acting rationally

Rational behavior: doing the right thing

The right thing: that which is expected to maximize goal achievement, given the available information

An agent is an entity that perceives and acts.

This course is about designing rational agents.

Abstractly, an agent is a function from percept histories to actions

f : P A

For any given class of tasks and environments, we seek the agent with the best performance.

Problem: Acting rationally is NOT

Computational limitations make perfect rationality unachievable

Design best program for given machine resources

Which of the following can be done at present?

• Play a decent game of table tennis

• Drive safely along a curving mountain road

• Drive safely along Telegraph Avenue

• Buy a week’s worth of groceries on the web

• Discover and prove a new mathematical theorem

• Design and execute a research program in biology

• Write an intentionally funny story

• Give legal advice in a specialized area of law

• Translate spoken English into Swedish in real time

• Perform a complex surgical operation

• Converse successfully with another person for an hour