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FRE 2672
Urban Ontologies : the Towntology prototype towards case studies
Chantal BERDIER (EDU),
Catherine ROUSSEY (LIRIS)
2
Ontology DefinitionsGruber 1993: « the specification of conceptualisations, used
to help programs and humans share knowledge. »
Studer 1998 : « Ontology is a formal and explicite specification of a share conceptualisation. »
The conceptualization is an abstract, simplified view of the world that
has to be represented for some purpose.
The specification is the representation of this conceptualization in a concrete form. The goal is to create an agreed-upon vocabulary and semantic structure for exchanging information about that domain.
3
Ontology ObjectivesExpert System Knowledge based System
Knowledge separation from treatment in order to solve a specific problem or to achieve a task.
Knowledge reuse in different systems
Problem Solving MethodMethod input Method output
Method ontology
Application ontology
Domain ontology
Described by
mappingExtended to
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4 Ontology Classifications
Classification according to :
1.Formalization,
2.Expressiveness,
3.Purpose,
4.Specificity
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Classification according to Formalization
Depend on the language used to describe the ontology
highly informal: Yahoo directory
semi-informal: French Architecture Thesaurus
semi-formal: Dublin Core metadata Initiative in RDF.
rigorously formal: measurement ontology in KIF.
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Classification according to Expressiveness
Terms
Natural Language Definition
Concepts, class, type
Relation type, property type
Concept taxonomy
Relation type taxonomy
Properties and Attributes
Constraints
Formal definition
Axiom, facts
Rules
Lightweight Ontology
Heavyweight Ontology
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Classification according to Purpose Application ontology Ontolingua,
Protégé
Reference ontology PSL standard
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Classification according to SpecificityGeneric Ontology
Generic concept applicable on many fields
Example: measure concept
Core Ontology Core concept of urban domain applicable to urban field
Example: network concept
Domain Ontology Specific Concepts of a field.
Example: electricity network.
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Towntology ProjectFormalization: Semi informal / formal ontology
Expressiveness Lightweight Ontology
Purpose Reference ontology
Specificity Domain ontology
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Road System Ontology
roadway
Track
Bridge
Giratory
Structure
Draining road
PavementCycle strip
Cycle path
Urban trip
Building outline
Road way structure
Hierarchical Road
Road
Auscultation
Black
Undulation
Sevader
has tool
is a
is used for
is a computing tool forhas problem
has activity about
characterizeis located on
is composed ofhas tool
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Road System Visualisation in Context
ArbreCandélabre
Transport en commun
Potence
Feu de signalisation
Stationnement
Bordure
gauche
Marquage au sol
Figurine piéton
Potelet
Plaque de rue
Chaussée
Tree
Public transport
Desactivated concrete
bracket
Traffic lights
Parking
Kerb
Pedestrian crossing
Road marking
Pedestrian figurine
Road way
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7 classes of relationship typesRelation of localization « is located on » « is located in »
Relation of use : « is used for » « is used by » « can hold the role »
Relation of composition : « is composed of »
Relation of subordination : « depends on » « works for »
Relation of being : « is a(n) »
Relation of characterization « is characterized by » « says itself for »
Relation of generation: « is resulting from »
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Urban Mobility Ontology
Mode of transportationCaptive
User of road
Pedestrian
Car
walking cycling
Bus
Mean of public
transport
Noise Nuisance
Pollution
ExternalityDisabled person
Motorized mode of transportationMode of transportation not
motorized
Tramway Subway
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Urban Renewal Ontology
Urban renewal demolition
High rise estate
Is located on
reconstruction
Is composed of
Is followed by
operation
Is a
Social problem
unemployement
Is resulting from
educational failure
Is characterized by
Family of numerous childs
Functionalism theory
form
Construction period
Industrial techniques of building
Is linked
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Towntology report
To add the attributes and measurements
To develop a base of knowledge
Description of a particular situation
Example: the rehabilitation of the Lacassagne street in Lyon.
Limit of the tool :
All the concepts are represented in the same way
No visible hierarchy of concepts (identification of the level of specialization, or degree of association of the concept)
no filter on the domain/level, etc…
no regrouping of similar concepts in various fields (example : operation)
No global vision of the complexity of certain urban fields (example : urban renewal)
Sometimes a simplistic modelling of the field.
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Guidelines To make a good choise of Domain : technical
domain is easier Consensus and mathematical rigour
Documentation (dictionary, books, standards)
To think about the meaning of relations upstream Hierarchical relation
To think about general concepts and core concepts « general concepts » enable to build a good hierarchy
To define the difference between « brother concepts ».
To limit the number of relations
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Conclusion
All the fields of urban are not necessarily formalisable. A minimum of stability in the definitions is required.
Urban is able to generate any kind of ontology: formal, informal etc...
For example : technical fields of urban like roadway system can give rise to a formal ontology
Urban renewall for example give rise to abstract ontology.It Is a constructing domain.
One should not seek to make consensus but to create footbridges between various levels of vocabularies...