title
Chapter 1: Introduction
Chapter 2: Intelligent Agents
Lecture 2: Agents and Search
- options to design an AI agent
- designing rational agents
- search problems
- state space
- state space graph vs search tree
- search algorithm
Lecture 3: Informed Search
- search so far
- pancake problem
- fringe strategy - the one queue
- uniform cost search - ucs
- search heuristics
- greedy search
- a* search
- Optimality of A* Tree Search
- properties of A*
- A* applications
- tree search, graph search notices
- consistency of heuristics
- optimality of A* graph search & summary
- admissible heuristics & creating admissible heuristics
- example: 8 Puzzle I, II, III
- UCS vs A* Contours
- semi lattice of heuristics
- trivial heuristics, dominance
- search models & search gone wrong
Search Heuristics5
- Heuristic Function: Estimates how close a state is to a goal, designed for specific search problems.
- Examples: Manhattan distance, Euclidean distance for pathing.
Greedy Search
A* Search
- Combining UCS and Greedy: Orders by the sum of backward cost ( g(n) ) and forward cost ( h(n) ).
- Optimality of AΒ Tree Search*: Assumes admissible heuristics and claims that optimal goals will exit the fringe first.
- Properties of A*: Expands mainly toward the goal while ensuring optimality7.
- AΒ Applications*: Used in various fields like video games, routing problems, and language analysis.
- Tree Search and Graph Search Notices: Importance of detecting repeated states and implementing a closed set.
- Consistency of Heuristics: Ensures estimated heuristic costs are less than or equal to actual costs.
- Optimality of AΒ Graph Search & Summary: A is optimal with admissible/consistent heuristics, and heuristic design is crucial8.
Admissible Heuristics & Creating Admissible Heuristics9
- Admissibility: Heuristics must be optimistic and never outweigh true costs.
- Example - 8 Puzzle: Different heuristics like the number of tiles misplaced and total Manhattan distance.
UCS vs A* Contours10
- Comparison: UCS expands equally in all directions, while A* focuses mainly toward the goal.
Semi Lattice of Heuristics11
- Trivial Heuristics and Dominance: The concept of dominance and the semi-lattice structure of heuristics12.
Search Models & Search Gone Wrong
- Search and Models: The effectiveness of search is dependent on the accuracy of the world models.
- Search Gone Wrong: Issues that arise when models do not accurately represent the real world.