Urban Ontologies : the Towntology prototype towards case studies

1. Urban Ontologies : the Towntology prototype towards case studies Chantal BERDIER (EDU), Catherine ROUSSEY (LIRIS)

2. Ontology Definitions • Gruber 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 Objectives • Expert 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 Method input Method output Problem Solving Method Described by Extended to mapping Domain ontology Application ontology Method ontology

4. 4 Ontology Classifications Classification according to : • Formalization, • Expressiveness, • Purpose, • Specificity

5. 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.

6. 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

7. Classification according to Purpose • Application ontology • Ontolingua, • Protégé • Reference ontology • PSL standard

8. Classification according to Specificity • Generic 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.

9. Towntology Project • Formalization: • Semi informal / formal ontology • Expressiveness • Lightweight Ontology • Purpose • Reference ontology • Specificity • Domain ontology

10. List of terms Semantic network Towntology Browser

11. Interactive zones List of concepts Image Browser

12. Towntology Browser: Information Frame relations definitions references Image

13. Road System Ontology Hierarchical Road Structure Black has tool Draining road is a has activity about Undulation has problem Road is a computing tool for Sevader is composed of has tool Giratory Auscultation roadway Bridge is used for Urban trip Track characterize is located on Pavement Cycle strip Building outline Road way structure Cycle path

14. Tree Arbre Candélabre Feu de signalisation Traffic lights bracket Potence Plaque de rue Transport en commun Public transport Figurine piéton Chaussée Road way Pedestrian figurine Stationnement Parking Pedestrian crossing Potelet Desactivated concrete Kerb Bordure Road marking Marquage au sol gauche Road System Visualisation in Context

15. 7 classes of relationship types • Relation 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 »

16. Urban Mobility Ontology Externality Disabled person Pollution Pedestrian Noise Nuisance User of road Captive Mode of transportation Motorized mode of transportation Mode of transportation not motorized Car Mean of public transport walking cycling Bus Tramway Subway

17. Is located on operation Is a Is composed of Urban renewal demolition Is followed by Is characterized by reconstruction Is resulting from Is linked Social problem High rise estate unemployement Industrial techniques of building educational failure Functionalism theory form Family of numerous childs Construction period Urban Renewal Ontology

18. 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.

19. 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

20. 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...