introduction to agents and multi-agent systems (lecture slides)
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D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Introduction to Agents and
Multi-agent systems
Prof. Dr. Dagmar Monett Díaz Computer Science Dept.
Faculty of Cooperative Studies
Berlin School of Economics and Law
dagmar@monettdiaz.com
Europe Week, 3rd – 7th March 2014
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 2
Two “intelligent” agents…
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Dilbert
Scott Adams
At http://dilbert.com/strips/comic/1991-02-08/
(Educational/Classroom usage permission is granted by Universal Uclick. All Rights Reserved)
“Intelligent” travel agent #1
3
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Dilbert
Scott Adams
At http://dilbert.com/strips/comic/1996-12-23/
(Educational/Classroom usage permission is granted by Universal Uclick. All Rights Reserved)
“Intelligent” travel agent #2
4
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 5
Another kind of “intelligent” agent
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Travel agent: simple case
"Stimulus-response„ search engine
Customer: Agent:
Specifies request with preferences
[Fill out form]
Specifies answer
[Show matching
offers]
6
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Travel agent: more complex
Customer: Agent:
I want to go on vacation
Wonderful!
Do you like
swimming?
7
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Travel agent: more complex
Customer: Agent:
Yes, with good friends on a white beach. And I like sports.
Wonderful!
And in the evening?
8
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Travel agent: more complex
Customer: Agent:
Good entertainment, exclusive bars, etc.
Sounds fantastic. Is this what you are looking for? [Present an offer]
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D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Travel agent: more complex
Customer: Agent:
Really fantastic but over my budget. I‘d prefer something less exclusive...
Let's see… How about this? [Present a new offer]
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D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 11
What would that agent need for the
dialog?
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Travel agent: more complex
12
Such a travel agent would need its knowledge to be
dynamic:
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Travel agent: more complex
13
Such a travel agent would need its knowledge to be
dynamic:
Dialog history
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Travel agent: more complex
14
Such a travel agent would need its knowledge to be
dynamic:
Dialog history
(Hypothetical) model of the customer’s and own
• desires, intentions
• preferences, opinions
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Travel agent: more complex
15
Such a travel agent would need its knowledge to be
dynamic:
Dialog history
(Hypothetical) model of the customer’s and own
• desires, intentions
• preferences, opinions
(Flexible) plan for
• exploring the customer’s desires and intentions
• profitable offers
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 16
Agenda
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 17
Agenda
Where does the major content come from?
What is an agent? What is a multi-agent system?
Agent types
Agent properties
Design of intelligent agents
Implementing practical reasoning agents
Further reading, sources of inspiration, and more…
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 18
©
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
An Introduction to
MultiAgent Systems
Michael Wooldridge
2nd Edition, 484 pp.
John Wiley & Sons, May 2009
ISBN-13: 978-0470519462
With materials available at
http://www.csc.liv.ac.uk/~mjw/pub
s/imas/IMAS2e.html
What I also use in my lectures at the HWR…
19
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Artificial Intelligence: A
Modern Approach
Stuart Russell and Peter Norvig
3rd Edition, 1152 pp.
Prentice Hall, December 2009
ISBN-13: 978-0136042594
With materials available at
http://aima.cs.berkeley.edu/
What I also use in my lectures at the HWR…
20
“The AI Bible”
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 21
What is an agent?
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Agents, a definition
22
According to Michael Wooldridge:
“An agent is a computer system that is
capable of independent action on behalf of
its user or owner (figuring out what needs to
be done to satisfy design objectives, rather
than constantly being told)”.
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Agents, a definition
23
According to Michael Wooldridge:
“The main point about agents is they are
autonomous: capable of acting
independently, exhibiting control over their
internal state.
Thus: an agent is a computer system
capable of autonomous action in some
environment in order to meet its design
objectives”.
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Agents, a definition
24
According to Russell and Norvig:
“An agent is anything that can be viewed as
perceiving its environment through sensors
and acting upon that environment through
actuators”.
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 25
Agents
Agents communicate with the environment
through Sensors and Actuators
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 26
What is a multi-agent system?
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Dilbert
Scott Adams
At http://dilbert.com/strips/comic/1998-08-29/
(Educational/Classroom usage permission is granted by Universal Uclick. All Rights Reserved)
Agent in a group
27
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Multi-agent systems, a definition
28
According to Michael Wooldridge:
“A multi-agent system is one that consists of
a number of agents, which interact with one-
another”.
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Multi-agent systems, a definition
29
According to Michael Wooldridge:
“A multi-agent system is one that consists of
a number of agents, which interact with one-
another”.
In the most general case, agents will be acting on
behalf of users with different goals and motivations
To successfully interact, they will require the ability
to cooperate, coordinate, and negotiate with each
other, much as people do
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 30
Agent types
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Agent types
Four basic types in order of increasing
generality:
Simple reflex agents
Model-based reflex agents
Goal-based agents
Utility-based agents
31
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 32
Simple reflex agents
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 33
Model-based reflex agents
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 34
Goal-based agents
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 35
Utility-based agents
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 36
Learning agents
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Dilbert
Scott Adams
At http://dilbert.com/strips/comic/2004-04-19/
(Educational/Classroom usage permission is granted by Universal Uclick. All Rights Reserved)
A real state agent
37
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 38
Agent properties
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Intelligent agents are…
reactive
pro-active
social
rational
benevolent
adaptable
truthful
autonomous
mobile
A reactive system is one that
maintains an ongoing interaction
with its environment, and responds
to changes that occur in it (in time
for the response to be useful).
39
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Intelligent agents are…
reactive
pro-active
social
rational
benevolent
adaptable
truthful
autonomous
mobile
Pro-activeness = generating and
attempting to achieve goals; not
driven solely by events; taking the
initiative; recognizing opportunities.
40
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Intelligent agents are…
reactive
pro-active
social
rational
benevolent
adaptable
truthful
autonomous
mobile
Social ability in agents is the ability
to interact with other agents (and
possibly humans) via some kind of
agent-communication language, and
perhaps cooperate with others.
41
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Intelligent agents are…
reactive
pro-active
social
rational
benevolent
adaptable
truthful
autonomous
mobile
An agent should strive to do the
right thing, based on what it can
perceive and the actions it can
perform. The right action is the one
that will cause the agent to be most
successful.
An agent will act in order to achieve
its goals, and will not act in such a
way as to prevent its goals being
achieved – at least insofar as its
beliefs permit
42
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Intelligent agents are…
reactive
pro-active
social
rational
benevolent
adaptable
truthful
autonomous
mobile
Agents do not have conflicting
goals. Every agent will therefore
always try to do what is asked of it.
43
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Intelligent agents are…
reactive
pro-active
social
rational
benevolent
adaptable
truthful
autonomous
mobile
Agents improve performance over
time. They can learn.
44
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Intelligent agents are…
reactive
pro-active
social
rational
benevolent
adaptable
truthful
autonomous
mobile
An agent will not knowingly
communicate false information
45
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Intelligent agents are…
reactive
pro-active
social
rational
benevolent
adaptable
truthful
autonomous
mobile
An agent is autonomous if its
behaviour is determined by its own
experience (with ability
to learn and adapt)
46
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Intelligent agents are…
reactive
pro-active
social
rational
benevolent
adaptable
truthful
autonomous
mobile
Mobility: the ability of an agent to
move around an electronic network
47
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 48
Design of intelligent agents.
Examples
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Settings
49
Performance measure
Environment
Sensors
Actuators
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Settings
50
Performance measure
Environment
Sensors
Actuators
Designing an automated taxi driver:
Safe, fast, legal, comfortable trip, maximize profits
Roads, other traffic, pedestrians, customers
Cameras, speedometer, GPS, engine sensors, keyboard, etc.
Steering wheel, accelerator, brake, signals
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Settings
51
Performance measure
Environment
Sensors
Actuators
Designing a medical diagnosis system:
Healthy patient, minimize costs, lawsuits
Patient, hospital, staff
Keyboard (entry of symptoms, findings, patient's answers)
Screen display (questions, tests, diagnoses, treatments, referrals)
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Settings
52
Performance measure
Environment
Sensors
Actuators
Designing an interactive English tutor:
Maximize student's score on test
Set of students
Keyboard
Screen display (exercises, suggestions, corrections)
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 53
Active learning exercise:
“How to implement
reactive agents?
Discuss it with your classmates!”
Image © renjith krishnan at http://www.freedigitalphotos.net/
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 54
Implementing deliberative agents.
First steps.
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Agent Control Loop Version 1 while true observe the world; update internal world model; deliberate about what intention to achieve next; use means-ends reasoning to get a plan for the intention; execute the plan end while
First pass
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
More formally…
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
With deliberation…
[…which can be further extended to consider practical reasoning agents…]
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Dilbert
Scott Adams
At http://dilbert.com/strips/comic/2004-04-23/
(Educational/Classroom usage permission is granted by Universal Uclick. All Rights Reserved)
The real state agent (cont.)
58
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 59
Homework:
“Search for real-world applications
that use intelligent agents and
describe their tasks and
functioning!”
Image © renjith krishnan at http://www.freedigitalphotos.net/
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 60
Assessment
Image © renjith krishnan at http://www.freedigitalphotos.net/
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Question
61
(Taken from a public sample exam © Wooldridge)
Briefly define and explain, with examples where
appropriate, THREE properties you would
expect an intelligent agent to exhibit!
PLEASE ANSWER AT:
https://docs.google.com/forms/d/1K0RZur9bDtZs0R0k74GKn7Va34ALPYtXxXUFJH51_1k/viewform
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 62
Last active learning exercise
Image © renjith krishnan at http://www.freedigitalphotos.net/
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 63
The content
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 64
References
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Others…
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D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield
Further reading and sites…
IFAAMAS – International Foundation for
Autonomous Agents and Multiagent Systems
http://ifaamas.org/
Journal Autonomous Agents and Multi-Agent
Systems
http://link.springer.com/journal/10458
13th International Conference on Autonomous
Agents ans Multiagent Systems (AAMAS’14), Paris,
France
http://aamas2014.lip6.fr/
66
D. Monett – Europe Week 2014, University of Hertfordshire, Hatfield 67
Slides of the talk per request:
dagmar@monettdiaz.com
Prof. Dr. Dagmar Monett Díaz
monettdiaz
@dmonett
http://monettdiaz.com
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