ifcWOD (Web Of Data) - Semantically Adapting IFC Model Relations into OWL Properties

AnaROXIN–ana-maria.roxin@u-bourgogne.fr
TracisioMENDESDEFARIAS-tarcisio.mendes-de-farias@u-bourgogne.fr
IfcWoD (Web of Data)
Semantically Adapting IFC Model Relations
into OWL Properties
Tarcisio Mendes de Farias, Ana Roxin and
Christophe Nicolle
Standards Summit – Rotterdam
April 11 - April 14

Agenda
Motivation
• General context presentation
• Semantic Web technologies for IFC
Approach
• General presentation of ifcWOD
• Semantic adaptation of IFC relations
Benefits
• Simplifying query writing
• Reducing query execution time
• Reducing data redundancy
April 12th 2016 ifcWOD 2

MOTIVATION

General Context
Linked data
• Good practices for publishing and connecting data on the Semantic Web
• URIs
• Network Protocol HTTP
• Semantic Web standards RDF
• Links among vocabularies
Building Information Modeling (BIM)
• IFC (Industrial Foundation Classes) is the ISO standard for BIM
• Information exchange based on STEP file format
How Linked Data (LD) can help in the context of BIM ?
• Enhancing BIM interoperability
• Static format (file-based) vs RDF

Semantic Web technologies for IFC
OWL for IFC
EXPRESS vs. OWL
• STEP-based files vs RDF triples
• Object-oriented vs graph modelling
Semantically adapting IFC
into OWL
• IFC relationships
Intuitive building information
manipulation
ifcOWL
IFC-based ontology
• Direct syntax mapping of IFC
EXPRESS specification
BuildingSMART Linked Data
Working Group
W3C Linked Building Data
Community Group

ifcOWL drawbacks
Understanding of IFC
object properties and
relationships
Access to the
semantics of building
data
Correct application of
Linked Data principles
No leverage from
constraints dictated by
the EXPRESS/STEP file
format
“An ontology is a formal, explicit specification of a shared conceptualization”
Studer, R., Benjamins, R. & Fensel, D., 1998. Knowledge engineering: Principles and methods. Data & Knowledge Engineering,
25(1–2), p. 161–198.

PROPOSED APPROACH

ifcWoD, IFC Web of Data Ontology
◼ Semi-automatically conceived, based on:
 IFC EXPRESS model
 IfcOWL
 Property Set Definition (PSD)
◼ Main contributions:
Adaptation
of existing
IFC
properties
ifcRelationship
ifcProperty
New
properties
ifcwod:isDefinedBy_ifcObject
ifcwod:operatesOn

Adapting ifcRelationship into OWL
◼ We semantically adapt ifcRelationship entities into OWL
 Inverse and Relating[name of relating object] attributes
Our approach can be applied on all 41
ifcRelationship subtypes of the IFC
standard.
Only 14 of these subtypes have
additional semantic attributes, for
which the ifcOWL representation is
needed.

Adaptation of ifcRelationship
◼ IFC properties and relationships in the IfcWOD ontology schema
ifcowl:IfcRelDefinesByProperties
ifcowl:IfcObjectDefinition ifcowl:IfcPropertySetDefinitionSelect
ifcowl:IfcWallStandardCase ifcowl:IfcPropertySet
rdfs:subClassOf rdfs:subClassOf
ifcowl:RelatingPropertyDefinition_
of_IfcRelDefinesbyProperties
ifcowl:RelatedObjects_of_IfcRel
DefinesbyProperties
ifcwod:isDefinedBy_IfcObject

Adaptation of ifcProperty
◼ Idea: take advantage of PSDs
◼ ifcWoD: an IFC property is part of the schema
 Structured data
 Mapping rules from existing XSD files (Pset)
Mapping
Rule
Property Set Definition
(PSD) XSD
OWL
language
R1 <xs:complexType name="PropertyDef"> owl:ObjectProperty
R2 <xs:element type="xs:string" name="Name"> rdfs:label and URN
R3
<xs:element type="xs:string"
name="Definition">
rdfs:comment
R4 <xs:element name="NameAliases"> rdfs:label (@lang)
R5 <xs:element name="DefinitionAliases"> rdfs:comment (@lang)
R6
<xs:element type="PropertyType"
name="PropertyType">
rdfs:subPropertyOf and
rdfs:range

BENEFITS

Main advantages
IfcWoD allows enhancing reasoning
Easier query writing and relationship understanding
Reduction of query execution time
Reduction of data redundancy
 OWL transitive properties e.g.: ifcwod:isPredecessorTo_IfcProcess
SELECT ?x ?z { ?x ifcowl:IsPredecessorTo
?y. ?y
ifcowl:RelatingProcess_of_IfcRelSequence
?z. }
SELECT ?x ?y {?x
ifcwod:isPredecessorTo_IfcProcess ?y}
 As proven by benchmarks

Simplifying query writing
◼ Q1 and Q1’ retrieve all external walls of a building project
◼ Q2 and Q2’ retrieve all doors and their references

Reducing query execution time
Test environment
• Server: Stardog Intel Xeon CPU E5-2430 at 2.2GHz with 2 cores out of
6, 8GB of DDR3 RAM memory
• Client machine Intel Core CPU I7-4790 at 3.6GHz with 4 cores, 8GB of
DDR3 RAM memory at 1600MHz
• Building Project: ACTIVe3D (11MB STEP file)
• Queries – each executed 30 times
• Q1, Q2 and Q3 are solely composed of IfcOWL terms
• Q1’, Q2’ and Q3’ are composed of IfcWoD terms
Q1 Q1’ Q2 Q2’ Q3 Q3’
Mean (seconds) 0.242 0.026 0.516 0.025 1.348 0.056
Standard Deviation 0.024 0.009 0.019 0.008 0.024 0.017
#Results 37 37 141 141 67 67
Mean Time Reduction (%) 89.26% 95.15% 95.85%

Reducing data redundancy
Modelling
data
without
IfcWoD
Modelling
data
with IfcWoD

Conclusion and Future Works
Semantic
modelling
of IFC
relations in
OWL
Novel modelling that allows an easen application of the
Linked (Open) Data principles
Semi-automatic method for ontology conception
IfcWoD
linked to
IfcOWL
Simplifies query writing
Improves query response time for retrieving building
data
Future
works
Analyze the trade-off between data redundancy and
query performance
Study the gathering and the inheritance of common
properties in the PSDs

Thank you for your attention
Tarcisio Mendes de Farias – tarcisio.mendesdefarias@checksem.fr
Ana Roxin – ana-maria.roxin@u-bourgogne.fr

ifcWOD (Web Of Data) - Semantically Adapting IFC Model Relations into OWL Properties

More Related Content

Viewers also liked (20)

Similar to ifcWOD (Web Of Data) - Semantically Adapting IFC Model Relations into OWL Properties (20)

More from Ana Roxin (11)

Recently uploaded (20)

ifcWOD (Web Of Data) - Semantically Adapting IFC Model Relations into OWL Properties