CSC462-AI Lec02 Slides
CSC462-AI Lec02 Slides
CSC462-AI Lec02 Slides
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AGENTS
systems that can reasonably be called intelligent. e.g. Human
Agent, Robotic Agent, Software Agent (software robot or softbot)
ENVIRONMENT
The environment could be everything—the entire
universe! or a subset of universe e.g. Road, classroom,
virtual environments
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AGENTS AND ENVIRONMENTS
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PERCEPT SEQUENCE
percept sequence is the complete history of everything
the agent has ever perceived.
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AGENT FUNCTION
an agent’s behavior is described by the agent function
that maps any given percept sequence to an action.
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RATIONAL AGENT
A rational agent is one that does the right thing.
PERFORMANCE MEASURES
• We evaluate an agent’s behavior by its consequences.
• When an agent is plunked down in an environment, it generates a sequence of
actions according to the percepts it receives.
• This sequence of actions causes the environment to go through a sequence of states.
• If the sequence is desirable, then the agent has performed well.
• This notion of desirability is captured by a performance measure that evaluates
any given sequence of environment states.
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RATIONALITY
What is rational at any given time depends on four things:
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SPECIFYING THE TASK ENVIRONMENT
In designing an agent, the first step must always be to specify the task
environment as fully as possible including
• the performance measure
• the environment
• the agent’s actuators
• the agent’s sensors
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PROPERTIES OF TASK ENVIRONMENTS
• FULLY OBSERVABLE VS. PARTIALLY OBSERVABLE
• SINGLE-AGENT VS. MULTI-AGENT
• DETERMINISTIC VS. NONDETERMINISTIC
• EPISODIC VS. SEQUENTIAL
• STATIC VS. DYNAMIC
• DISCRETE VS. CONTINUOUS
• KNOWN VS. UNKNOWN
AGENT PROGRAM & AGENT ARCHITECTURE
• The job of AI is to design an agent program that implements the
agent function—the mapping from percepts to actions.
• this program will run on some sort of computing device with physical
sensors and actuators—we call this the agent architecture:
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AGENT PROGRAMS
• SIMPLE REFLEX AGENTS
• MODEL-BASED REFLEX AGENTS
• GOAL-BASED AGENTS
• UTILITY-BASED AGENTS
• LEARNING AGENTS
SIMPLE REFLEX AGENT
SIMPLE REFLEX AGENTS
AN AGENT PROGRAM FOR VACUUM AGENT
MODEL-BASED REFLEX AGENT
GOAL-BASED AGENTS
UTILITY-BASED AGENTS
LEARNING AGENT