Dictionary Ontology

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DictionaryOntology
-based modelling their use in product
modelling

• G. Pierra,
• LISI/ENSMA

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Contents

• Why two-level modelling?
• What?
• How?

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Dictionaries/ontologiesWhy?

• 1- ? model complexity
• cost-of-implementation C x (number-of-entities
  )?
• gt to distinguish 2 kinds of entities
• those that shall be understood by the software
• 1 curve (....) gt display the shape
• ? information model
• those that shall be recorded / transmitted /
  displayed by the software
• 1 property_value ('thread_pith',0.5,'mm', 10
  )
• 10class('hexagonal screw') gtrecord/display
• ? put in a dictionary /ontology referenced
  from information model

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Dictionaries/ontologiesWhy?

• 2- ? model flexibility
• Always new components, new technical properties
• "hard-encoded" in information model gt new
  release!
• If referenced gt only extends dictionary
• 3- ? model stabilityInformation model
  Universe of discourse context
• Usual information modelling method mix
• concept definitions rather stable, and
• concept representation, role and relationships in
  some context highly changing

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Dictionaries/ontologiesWhy?Ontology-based
modelling (OBM)
Domain
OOM paradigm
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Dictionaries/ontologiesWhy? (end)

• 4 - ? model interoperability
• the same dictionary may be used in very different
  context, e. g,
• engineering
• e-commerce
• NoteGreat difference with instance values of a
  particular model (Reference data library)
• extends domains of this model
• no action on interoperability

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Dictionaries/ontologiesWhat?

• Two things

• 1- dictionary model ( "meta-modelling")
• rather simple entity-relationship inheritance
• classes
• properties
• inheritance
• data type
• mechanisms for managing complexity
• 2- referencing mechanism
• dictionary / ontology entities shall be
  referencable
• easily
• unambiguously

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Dictionaries/ontologies for product modelling
What?

• Product / property dictionary
• Set of product and product property concepts
  with
• computer-sensible identification
• computer-sensible definition, and
• computer-sensible value representation

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Dictionaries/ontologies How? Common ISO/IEC
model

• A model that integrate requirements from two
  different committees
• Published in both IEC 61360-2 and ISO 13584-42
• flexibility
• An information model formally defined in EXPRESS
• reliability
• Reference capabilities
• from any application
• in any language (including EXPRESS and XML)
• openness

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Principles of the common ISO / IEC Dictionary

• to separate identification / definition

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Principles of the common ISO / IEC Dictionary

• Fundamental assumptionThe class hierarchy and
  the properties shall be defined together
• applicable properties precise the meaning of a
  class
• application domain precise the meaning of a
  property

• Simple inheritance

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Content of the common ISO / IEC Dictionary

• Properties values may have various data types

• Measures
• Ex Thread pitch in millimeter
• Codes translations pictures
• Ex Thread direction
• Levels min nom typ max
• Ex Overall length
• Integers
• Ex Thread quantity per inch
• Strings
• Ex Extra long reference number

English
Français
Code
AAG
Left-Hand
A Gauche
AAL
Right-Hand
A Droite
MIN
NOM
MAX
10
15
20
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Content of the common ISO / IEC Dictionary

• Typologie of properties

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Content of the common ISO / IEC Dictionary
From the engineering concept of model...
to multi-representation dictionaries

• General model object definition
• Functional model object representation
• Vue fonctionnelle representation point of view

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Content of the common ISO / IEC Dictionary

• PLIB Concepts Dictionary
• PLIB Concepts Catalogue
• PLIB a root format

• Class and property definition
• ISO/IEC 11179-3 1994 set of attributes

AAF307-005 01 NR3 S..3.3ES2 for
CCD124-002 E25 K-1 (en temp factor of
permeability fr facteur temporaire de
perméabilité) a_F (en temp factor of
reluctivity (fr facteur temporaire de
réluctivité) r_F Definition ( en The
value as specified by level (minTypMax) of the
negative of the change in the permeability due to
a change in temperature, divided by that change
in temperature (in K-1) of a soft magnetic
material at specified frequency. fr Valeur
indiquée par le niveau ... à une fréquence
spécifiée) AAE029-005frequency ref
IEC50(221.02.49) (1990)
dictionary definition of a property (IEC 61360-4)
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Exchange of PLIB dictionaries
ISO-10303-21 HEADER / DICTIONARY DESCRIPTION
/ /BSU for supplier / 20 SUPPLIER_BSU
('80///A123ER456YT', ) / BSU for
component_class / 60 CLASS_BSU ('PAW', '001',
20) / BSU for properties / 90
PROPERTY_BSU ('d_in', '001', 50) 100
PROPERTY_BSU ('d_out', '001', 50) 110
PROPERTY_BSU ('e', '001', 60) / Dictionary
properties description / / d_in / 91
NON_DEPENDENT_P_DET (90, , '001', 92,
TEXT('inner diameter'), , , , , (), , 'TO3',
93, ) 92 ITEM_NAMES (LABEL('inner
diameter'), (), LABEL(''), , ) 93
REAL_MEASURE_TYPE ('NR2..3.3', 94) 94
DIC_UNIT (95, ) 95 SI_UNIT (, .MILLI.,
.METRE.) .... / Dictionary class description
/ .... / PAW class / 81 COMPONENT_CLASS
(60, , '001', 82, TEXT('Class associated to
the PAW part family'), , , , 50, (110), (),
, (),(), ) 82 ITEM_NAMES (LABEL('PAW
family'), (), LABEL('PAW'), , )
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Life examples.
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CONCLUSION

• General infrastructure for product modelling
  needs both
• Application-oriented information model, and
• general purpose product/property dictionaries for
  sharing semantics across models
• Application-oriented information model may
  contain two aspects
• EXPRESS model, and
• Instance data (RDL) that allows to give a
  particular semantics to particular instances of a
  particular model without increasing model
  complexity
• gt Use the right tool for the right problem
• Referencing is not a problem developing
  dictionaries is
• Key issue for integration avoid competitive
  information model!