RE aula 4

1
Lexicon Based Ontology Construction
Julio Cesar Sampaio do Prado Leite - on leave at
the Karin Koogan Breitman
Departamento de Informática PUC- Rio R. Marquês
de São Vicente 225 22453-900 - Rio de Janeiro,
Brasil www.inf.puc-rio.br/julio
2
Ontologies

• Explicit meaning
• Integrate web resources
• interoperability

3
Ontology Definition Maedche02

• O C, R, HC, rel, AO consisting of
• Two disjoint sets, C (concepts) and R
  (relations)
• A concept hierarchy, HC HC is a directed
  relation HC ? C x C which is called concept
  hierarchy or taxonomy. HC (C1,C2) means C1 is a
  subconcept of C2
• A function rel R ? C x C that relates the
  concepts non taxonomically
• A set of ontology axioms AO, expressed in
  appropriate logical language.

4
Ontology development

• Developed by specialists
• There are some methodologies available Tove,
  Methontology, Noy McGuiness ...
• Most are either too vague or too heavyweight

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Lexicon Based Ontology Construction

• Can be performed by non specialists
• Bootstraps ontology construction because it is
  based on a mature lexicon development process
  (validaded in real life projects)
• Lighweight
• Focuses on the language
• Clarifies the separation between terms that have
  a special meaning from those pertaining to the
  minimal vocabulary.

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LEL

• Notion (denotation)
• Behavioral Responses (connotation)
• Entries are classified as
• object,
• subject,
• verb or
• state

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Example Leite93

• Returning/ Returned type verb
• Notions
• The process of a user giving checked out books
  back to the library.
• Performed by users.
• The user takes the books and his/her computer
  card to the circulation desk.
• Behavioral Responses
• If a book is overdue, a staff member charges a
  fine.
• A staff member must do the discharging.
• The book must be shelved.

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From lexicon to ontology
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Process overview
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Process example

• Substitute type subject
• Notions
• Person that attends a meeting in place of another
  person.
• He or she was appointed by the person invited to
  attend the meeting.
• Behavioral responses
• If cannot be present at meeting, sends absence
  notification.
• If can be present at meeting, sends presence
  confirmation.
• Is approved by meeting initiatior.

Lexicon entry
ontology
Process
Substitute Description (Documentation in
OIL) Person that attends a meeting in the place
of another person. He or she was appointed by the
person invited to the meeting.
3 Add a new concept to the concept list. The
concept name is the lexicon term itself 3.1
the concept description is the notion of the term
3.1.1 For each behavioral response check
3.1.1.1Check the relation ....
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Implementation example
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Contributions

• Provide systematic ontology construction process
• Facilitate ontology scoping (deciding between
  what terms to implement versus which ones to
  borrow from other ontologies)

13
QA

• The definition of "Agent" and "MAS (Multi-Agent
  System)
• as per Michael Wooldridge (http//www.csc.liv.ac.u
  k/mjw/pubs/imas/)
• Multiagent systems represent a new way of
  conceptualising and
• implementing distributed software
• An agent is a computer system that is capable of
  independent
• action on behalf of its user or owner.
• A multiagent system is one that consists of a
  number of agents,
• which interact with one-another
• In order to successfully interact, agents need
  ability to cooperate,
• coordinate, and negotiate

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QA

• The type of agent in the work that will be
  presented (cognitive /reactive)Cognitive

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QA

• The relationship between "Agents" and "Objects"
  in the work presented
• Not an issue in our work
• What is "Large Scale Multi-Agent System" in your
  work?
• Systems that deal with large and complex
  networks of resources and agents.