1. Intelligent Agents
Chapter 2

2. Outline Agents and environments Rationality
PEAS (Performance measure, Environment, Actuators, Sensors)
Environment types
Agent types

3. Agents
An agent is anything that can be viewed as perceiving its environment through sensors and acting upon that environment through actuators
Human agent:
Eyes, Ears, and other organs for Sensors;
Hands, Legs, Mouth, and other body parts for Actuators.
Robotic agent:
Cameras and Infrared range finders for Sensors;
Various Motors for Actuators.

4. Agents and Environments
[f: P*  A]
The agent program runs on the physical architecture to produce A.
agent = architecture + program

5. Vacuum-cleaner world
Function : (agent keeps Right and Left if both rooms are clean)

6. Vacuum-cleaner world Action Percept Right [A, Clean] Suck [A, Dirty]
Left
[B, Clean]
[B, Dirty]
Nop
[A, Clean] [B, Clean]

7. Rational agents
An agent should strive to "do the right thing", based on what it can perceive and the actions it can perform.
Performance measure: An objective criterion for success of an agent's behavior.
EX: Performance measure of a vacuum-cleaner agent:
- amount of dirt cleaned up,
- amount of time taken,
- amount of electricity consumed,
- amount of noise generated, etc.

8. Rational agents Rational Agent:
For each possible percept sequence, a rational agent should select an action that is expected to maximize its performance measure, given some built-in knowledge the agent has about the environment.
The performance measure that defines the criterion of success:
– The agent’s percept sequence to data.
– The agent’s prior knowledge of the environment.
– The actions that the agent can perform.

9. Rational agents • Is a vacuum-agent rational? (Depends!)
• Performance measure
– amount of dirt cleaned up,
– amount of time taken,
– amount of electricity consumed,
– amount of noise generated, etc..
• A priori بداهة
– Geography of the environment is known (two squares, A is on left and B is on right, etc.).
– Perception is trustable (no illusion وهم).
– Sucking cleans the current square .

10. Rational agents Actions – Left, right, suck. • Current percept
– [location, dirt]
• Possible extensions
– The agent have partial memory (reasoning percept histories).
– The geography of the environment is unknown.
– The agent cannot percept its current location.
– Agent can learn from experience.

11. Rational agents
Agents can perform actions in order to modify future percepts so as to obtain useful information (information gathering, exploration).
An agent is autonomous مستقل بذاته if its behavior is determined by its own experience (with ability to learn and adapt).

12. Specify the setting for intelligent agent design: PEAS Description
P : Performance measure
E : Environment
A : Actuators
S : Sensors
Must first specify the settings for intelligent agent design.

13. (Intelligent Transportation Systems)
PEAS
EX: Consider the task of designing an automated taxi driver:
(Intelligent Transportation Systems)
Performance measure: Safe, fast, legal, comfortable trip, maximize profits
Environment: Roads, traffic, pedestrians مشاة, customers.
Actuators: Steering wheel, accelerator, brake, signal, horn.
Sensors: Cameras, sonar, speedometer, GPS, odometer عداد المسافات, engine sensors, keyboard.

14. PEAS Agent: Medical diagnosis system
Performance measure: Healthy patient, minimize costs & lawsuits دعاوي قضائية.
Environment: Patient, hospital, staff.
Sensors: Keyboard (entry of symptoms أعراض, findings نتائج, patient's answers)
Actuators: Screen display (questions, tests فحوصات, diagnoses تشخيص, treatments علاج, referrals تحويل)

15. PEAS Agent: Interactive English tutor
Performance measure: Maximize student's score on test
Environment: Set of students
Sensors: Keyboard
Actuators: Screen display (exercises, suggestions, corrections)

16. PEAS Agent: Part-picking robot
Performance measure: Percentage of parts in correct bins صناديق
Environment: Conveyor belt with parts, bins
Sensors: Camera, joint angle sensors
Actuators: Jointed arm and hand

17. Environment types Fully observable (vs. partially observable):
An agent's sensors give it access to the complete state of the environment at each point in time.
– Playing chess? Fully.
– Medical diagnosis? Partially.
– Taxi driving? Partially.

18. Environment types Deterministic (vs. stochastic) قطعي/محدد:
The next state of the environment is completely determined by the current state and the action executed by the agent.
– Medical diagnosis? Stochastic.
– Battle field ميدان المعركة? Stochastic.
– E-shopping? Deterministic.
– E-auction? Stochastic.
– Playing chess? Strategic .
Strategic : If the environment is deterministic except for the actions of other agents.

19. Environment types Episodic (vs. sequential) سببي / حدثي :
An agent’s action depends only on an “episode” (snapshot) of the environment, i.e. history independent.
– Chess? Sequential.
– Web search? Episodic.

20. Environment types Static (vs. dynamic): The environment does not
change over time.
– Playing crossword puzzle كلمات متقاطعة? Static.
– Playing soccer? Dynamic.
– Battle field? Dynamic.

21. Environment types
Discrete (vs. continuous): A limited number of distinct, clearly defined percepts and actions.
– Playing chess? Discrete.
– Taxi driving? Continuous

22. Environment types • Single agent (vs. multi-agent):
An agent operating by itself in an environment.
– Crossword puzzle? Single
– Playing chess? Multi
– Taxi driving? Multi

23. Environment types
Chess with Chess without Taxi driving
a clock a clock
Fully observable Yes Yes No
Deterministic Strategic Strategic No
Episodic No No No
Static Semi Yes No
Discrete Yes Yes No
Single agent No No No
The environment type largely determines the agent design
The real world is (of course) partially observable, stochastic, sequential, dynamic, continuous, multi-agent

24. Relationship between Agents
• Collaborative vs. Competitive
– Playing chess? Competitive.
– Taxi driving? Cooperative,
• Trustworthy جدير بالثقة vs. Suspicious مشبوه
• Same capabilities or different
• Share information or not
• Delegate responsibility يفوض المسؤلية or not

25. Agent functions and programs
An agent is completely specified by the agent function mapping percept sequences to actions
One agent function (or a small equivalence class) is rational
Aim: find a way to implement the rational agent function concisely بايجاز

26. Agent types • Table-lookup agent – Huge table.
– Take a long time to build the table.
– No autonomy.
– Even with learning, need a long time to learn the table entries.

27. Agent types Four basic types in order of increasing generality:
Simple reflex agents
Model-based reflex agents
Goal-based agents
Utility-based agents

29. Simple reflex agents

31. Model-based reflex agents

33. Goal-based agents

35. Utility-based agents

36. Technologies of Software Agents
• Machine learning • Information retrieval • Agent communication • Agent coordination • Agent negotiation • Natural language understanding • Distributed objects