Agent Communication - Multi Agent Systems - Lecture Slides, Slides of Multiagent Systems

The key points in multiagent systems are:Agent Communication, Speech Acts, Treatments, Communication, Inspiration, Systems Borrow, Pragmatic Theories, Language, Physical Actions, Man and Wife

Typology: Slides

2012/2013

Uploaded on 04/30/2013

aradhana
aradhana 🇮🇳

4.6

(8)

119 documents

1 / 24

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Agent communication
Docsity.com
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12
pf13
pf14
pf15
pf16
pf17
pf18

Partial preview of the text

Download Agent Communication - Multi Agent Systems - Lecture Slides and more Slides Multiagent Systems in PDF only on Docsity!

Agent communication

Speech acts

  • Most treatments of communication in multi-agent systems borrow their inspiration from speech act theory
  • Speech act theories are pragmatic theories of language; they attempt to account for how language is used by people every day to achieve their goals and intentions.
  • The origins of speech act theories are usually traced to J.L. Austin’s book “How to do things with words”.
  • This is a philosophy book with a linguistic approach
  • Not a computer science book!

Speech acts (cont’d)

  • Searle (1969) identified various types of speech acts:
  • Representatives
    • Such as informing: “It is raining”
  • Directives
    • Attempts to get the hearer to do something, e.g. “please make the tea”
  • Commisives
    • Which commit the speaker to doing something, e.g. “I promise to”
  • Expressives:
    • Whereby a speaker expresses a mental state, e.g. “Thank you!”
  • Declarations:
    • Such as declaring a war

Speech acts (cont’d)

  • There is some debate about whether this (or any!) typology of speech acts is appropriate
  • In general, a speech act can be seen to have two components: - A performative verb (e.g. request, inform) - A propositional content (e.g. “the door is closed”)

Semantics of speech acts

  • How can one define the semantics of a speech act?
  • What is going to be the affect of the speech act to the world? - More exactly to the receiver?
  • The sender agent can not (generally) force a receiver agent to accept some desired mental state.
  • Different formalisms were proposed, depending on the representation of the world.

Plan based semantics

  • Cohen & Perrault (1979) defined the semantics of speech acts using the precondition-delete-add list formalism of planning research.
  • Semantics for a request: request(s, r, a)
  • Preconditions:
    • S believes r can do h
      • You don’t ask someone to do something unless you think they cando it
    • S believes h believes h can do a
      • You don’t ask someone unless they believe they can do it
    • S believes S wants a
      • You don’t ask someone unless you want it
  • Postconditions:
    • H believes s believes s wants a
      • The effect is to make them aware of your desire.

KQML

  • Developed by the ARPA knowledge sharing initiative
  • Composed of two parts:
  • Knowledge Query and Manipulation Language (KQML) - KQML is an “outer language”, that defines various acceptable “communicative acts” or performatives - Many critics say there were too many performatives (>40)
  • Knowledge Interchange Format (KIF) Docsity.com

FIPA ACL, introduction

  • FIPA (Foundation for Intelligent Physical

Agents) non-profit organization

  • Companies like IBM, Hitachi, HP, British Telecom, Siemens
  • Universities and research institutes
  • Started work on a program of agent standards,

the most important being the ACL (1997)

Example

(inform

:sender agent :receiver agent :content (price milk 100) :language sl :ontology hlp-auction

)

Performatives in FIPA

Inform

  • The content is a statement
  • Pre-conditions:
    • The sender holds that the content is true
    • Intends that the recipient believes the content
    • Does not already believe that the recipient is aware of whether the content is true or not.

Request

  • The content is an action.
  • Pre conditions:
    • The sender intends the action content to be performed
    • Believes the recipient is capable of performing the action
    • Does not believe that the sender already intends to perform the action.

Interaction protocols

  • A standard set of messages needed to achieve a certain goal
  • They are usually describing a time limited “conversation”

Protocols standardized by FIPA

  • FIPA Request
  • FIPA Query
  • FIPA Request When
  • FIPA Contract Net
  • FIPA Iterated Contract Net
  • FIPA English Auction
  • FIPA Dutch Auction
  • FIPA Brokering
  • FIPA Recruiting
  • FIPA Subscribe
  • FIPA Propose Interaction Docsity.com