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Please pick up a copy of the course syllabus from the front desk. http://www.pami.uwaterloo.ca/~khoury/ece457. Introduction to AI. ECE457 Applied Artificial Intelligence Spring 2007 Lecture #1. Outline. What is an AI? Russell & Norvig, chapter 1 Agents Environments - PowerPoint PPT Presentation
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ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 1
Please pick up a copy of the course syllabus from the front desk.
http://www.pami.uwaterloo.ca/~khoury/ece457
Introduction to AI
ECE457 Applied Artificial IntelligenceSpring 2007 Lecture #1
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 3
Outline What is an AI?
Russell & Norvig, chapter 1 Agents Environments
Russell & Norvig, chapter 2
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 4
Artificial Intelligence
Computer players in video games
Robotics Assembly-line robots,
auto-pilot, Mars exploration robots, RoboCup, etc.
Expert systems Medical diagnostics,
business advice, technical help, etc.
Natural language Spam filtering,
translation, document summarization, etc.
Artificial intelligence is all around us
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 5
What is an AI? Systems that…
Rationality vs. Humans: emotions, instincts, etc.
Thinking vs. acting: Turing test vs. Searle’s Chinese room
Engineers (and this course) focus mostly on rational systems
Humanly Rationally
Think Neural networks
Theorem proving
Act ELIZA Deep Blue
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 6
Act Rationally Perceive the environment, and act so as to
achieve one’s goal Not necessary to do the best action
There’s not always an absolutely best action There’s not always time to find the best action An action that’s good enough can be acceptable
Example: Game playing Sample approach: Tree-searching strategies Problem: Choosing what to do given the
constraints
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 7
Think Rationally Uses logic to reach a decision or
goal via logical inferences Example: Theorem proving Sample approach: First-order logic Problems:
Informal knowledge Uncertainty Search space
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 8
1. X = Y/Z XZ = Y2. X = Y
X + Z = Y + Z
3. X * Y + X * Z X * (Y + Z)
4. b/c = AH/b5. a/c = BH/a6. AH + BH = c
Think Rationallya. b² = AH * cb. a² = BH * cc. a² + b² =
BH * c + AH * c
d. a² + b² = c * (AH +
BH)e. a² + b² = c²
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 9
Act Humanly “Turing-test” AI Improve human-machine
interactions up to human-human level
Drawbacks: In some cases, requires dumbing
down the AI Lots of man-made devices work well
because they don’t imitate nature
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 10
Think Humanly Cognitive science Neural networks Helps in other fields
Computer vision Natural language processing
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 11
Rational Agents An agent has
Sensors to perceive its environment
Actuators to act upon its environment
A rational agent has an agent program that allows it to do the right action given its precepts
Environment
Perce
pts A
ction
s
Sensors
Actuators
Agent Progra
m
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 12
Properties of the Environment Fully observable vs. partially observable
Chess vs. Stratego Deterministic vs. stochastic vs. strategic
Sudoku vs. Yahtzee vs. chess Episodic vs. sequential
Face recognition vs. chess Static vs. dynamic vs. semi-dynamic
Translation vs. driving vs. chess with timer Discrete vs. continuous
Chess vs. driving Single agent vs. cooperative vs.
competitive Sudoku vs. sport team vs. chess
ECE457 Applied Artificial Intelligence R. Khoury (2007) Page 13
Types of Agents Simple reflex agent
Selects action based only on current perception of the environment
Model-based agent Keeps track of perception history
Goal-based agent Considers what will happen given its actions
Utility-based agent Adds the ability to choose between
conflicting/uncertain goals Learning agent
Adds the ability to learn from its experiences