Artificial Intelligence Artificial Intelligence Artificial - PowerPoint PPT Presentation

Artificial Intelligence

Artificial Intelligence

Artificial Intelligence Study and design of machines that can think like a human being Attempt to understand human intelligence

Artificial Intelligence But how do you define intelligence? Umbrella term Abstract thought, understanding, communication, reasoning and learning, planning and problem solving Goal: understand primary issues involved and the challenges

Example: Turing Test A behavioral test to determine whether a computer system is intelligent ● Natural language processing ● Knowledge about various topics ● Reasoning Weak equivalence : The equality of two systems based on their results Strong equivalence : The equality of two systems based on their results and the process by which they arrive at those results

Foundations of AI Psychology How do humans and animals think and act? Computer Science/Engineering How to build an efficient computer system? Linguistics How does language relate to thought?

Data Sources Natural language Mathematical notation Imagery data Written text Music

Semantic network A graph or network that presents meaningful relationships among objects/concepts has Cat Vertebra Fur is a has has is a Bear is a Mammal Animal is a is a Whale lives in lives in Fish Water

Thought Question Think of five questions that you might issue as the interrogator of a Turing test. Why would a computer have difficulty answering them well? Please explain your reasoning.

Search Trees Hierarchical structures that represents the alternatives of situations/choices Nodes/Vertices : Points in a tree that contains some form of data Edges/Arcs : Link between nodes in a search tree Game tree : is a graph whose nodes are the positions in a game and whose edges are moves

Search Trees Parent nodes P Nodes/Vertices Child nodes Leaf nodes Edges/Arcs 7 P P P C C C 9 5 8 P P P L C C C 2 4 3 6 0 L 12 3 6 1 4 7 5 L L L L L L L

Game Trees Depth first search Breadth first search Player 1 Player 2 Player 1 Wins! Wins! Player 2

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A* Search State of the art method in searching a tree A "Greedy" and "Best First Search" method Each possible next node in a graph is considered based on a heuristic (guess of future cost) and current cost. Simple yet powerful

Visual Example http://upload.wikimedia. org/wikipedia/commons/5/5d/Astar_progres s_animation.gif