Thesis presentation from the public defence on May 5th 2021

1. Harmonizing and linking conceptual
models of geospatial information
Technologies for information modelling in
Geographic Information Systems (GIS), Intelligent Transport Systems (ITS) and
Building Information Modelling (BIM)
Knut Jetlund
Norwegian University of Science and Technology
Norwegian Public Roads Administration
knut.jetlund@vegvesen.no
Twitter: @Jetgeo
LinkedIn: https://www.linkedin.com/in/knut-jetlund/
Photo: Knut Opeide, Statens vegvesen
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2. Agenda
• Motivation
• Research questions
• Scientific approach
• Theory
• Results
• Conclusions
• Further work
Photo: Knut Opeide, Statens vegvesen
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3. Three application domains,
one real world
GIS
Analyze and present
BIM
Plan, develop,
construct and maintain
ITS
Plan and control
transportation
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Photo: Knut Opeide, Statens vegvesen

4. Reuse of information across domain borders
• The challenge:
• Reuse requires a common
understanding of how the real
world is described in information
models
• Modelling language
• Terminology
• Geometry and location
referencing
• Exchange formats
GIS
Analyze and present
BIM
Plan, develop,
construct and maintain
ITS
Plan and control
transportation
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Photo: Knut Opeide, Statens vegvesen

5. Research question:
“How can approaches and
technologies for information
modelling be applied for
harmonization and linking of
conceptual models of
geospatial information from
the three application
domains of GIS, ITS and
BIM?”
Harmonization
GIS
Linking
BIM ITS
Harmonization
Harmonization
How can we achieve a common understanding?
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6. SRQ1
State
of
the
art
SRQ2 GIS-ITS
SRQ3 GIS-BIM
SRQ4 Harmonization
SRQ5 Ontologies and linking
Article 1 Article 5 CP1 SP3
Article 4 Article 5 SP4
Article 5 Article 1 Article 4
Article 2 Article 3 Article 4
Article 3
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7. Scientific approach
GIS
BIM ITS
SRQ3 SRQ2
SRQ4
SRQ5
A generic information
model for exchange GIS
to ITS
Modelling rules and rules for
conversion from UML to OWL
A structure of UML profiles for
GIS, ITS and BIM
IFC schemas in ISO/TC
211 UML
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8. DIKW
- Data, Information, Knowledge and Wisdom
Data
Information
Knowledge
Wisdom
Information model:
• “… a formal description of types of ideas, facts
and processes which together form a model of a
portion of interest of the real world and which
provides an explicit set of interpretation rules.”
(Schenck and Wilson, 1994).
• “… a representation of concepts, relationships,
constraints, rules, and operations to specify data
semantics for a chosen domain of discourse”
(Zhao et al., 2011)
The DIKW Hierarchy. Adapted from (Rowley, 2007).
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9. Information modelling
Real world
Universe of discourse
Context
Perceived in
the context of
Defined in
Conceptualschema
Formally represented in
Conceptualschema language
Formal language
for representing
Conceptualmodel
Conceptualformalism
Provides concepts
for describing
Basis for
From the real world to conceptual models.
Adapted from ISO 19101-1:2014
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10. Results
Photo: Torbjørn Braset, Statens vegvesen
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11. SRQ1: State of the art
“What approaches and
technologies have been used for
modelling geospatial information
in GIS, ITS and BIM?”
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• All three application domains:
– Conceptual schemas in UML
– Some degree of MDA
• UML and MDA for GIS the
most complete approach
– But with defeciencies

12. SRQ2: Information exchange from GIS to ITS
“How can models for exchange of
geospatial information from road
and mapping authorities to
geospatial databases for ITS be
improved?”
Requirement
Req 1: ISO/TC 211 MDA
Req 2: GIS exchange format
Req 3: Feature catalogue
Req 4: Feature catalogue exchange model
Req 5: Network model
Req 6: Generic feature exchange model
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13. 13
ISO/TC 211 MDA
GIS exchange format
Feature catalogue
Feature catalogue exchange model
Network model
Generic feature exchange model
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Prototype experiment

14. 14
Validation: The GIS to ITS prototype
Requirement Prototype approach
Req 1: ISO/TC 211 MDA Yes
Req 2: GIS exchange format Yes – GML in the prototype
Req 3: Feature catalogue
Any feature catalogue described as an ISO 19109
application schema.
Tested with INSPIRE and GDF in a case study
Req 4: Feature catalogue exchange model Yes – Implemented in GML
Req 5: Network model Yes
Req 6: Generic feature exchange model Yes – Implemented in GML
Future improvements:
• More complex road network models (GDF, NDS)
• Belts and Traffic spaces (GDF 5.2 and CityGML 3.0)
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15. Syntactic
Semantic
Implementation
SRQ3: Integration of
models for GIS and BIM
“How can information models and
semantics for implementation
technologies for BIM be integrated
and linked with GIS standards?”
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16. • Syntactic interoperability
– Most EXPRESS concepts
maintained
• Semantic interoperability
– Not all concepts could be linked
– Common concept preferred
• Implementation
– Extra semantics for EXPRESS
– Mapping of geometry concepts
vital for GML
Validation:
The BIM/GIS prototype
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«FeatureType»
IfcProductExtension::IfcAlignment
+ predefinedType: IfcAlignmentTypeEnum [0..1]
::IfcObject
+ objectType: CharacterString [0..1]
::IfcRoot
+ globalId: IfcGloballyUniqueId
+ name: CharacterString [0..1]
+ description: CharacterString [0..1]
IfcGeometricRepresentationItem
«FeatureType»
IfcGeometryResource::IfcCurve
+ /dim: Integer
+ curve: Curve [0..1]
constraints
{derive dim}
IfcPositioningElement
«FeatureType»
IfcProductExtension::
IfcLinearPositioningElement
«FeatureType»
IfcGeometryResource::
IfcBoundedCurve
«FeatureType»
IfcGeometricConstraintResource:
:IfcAlignmentCurve
+ tag: CharacterString [0..1]
IfcGeometricRepresentationItem
«FeatureType»
IfcGeometricConstraintResource::
IfcAlignment2DHorizontal
+ startDistAlong: Length [0..1]
IfcAlignment2DSegment
«FeatureType»
IfcGeometricConstraintResource::
IfcAlignment2DHorizontalSegment
List aggregate
«FeatureType»
IfcGeometryResource::IfcCurveSegment2D
+ startDirection: Angle
+ segmentLength: Length
«EXPRESS_DERIVE»
{derive dim : Dim : IfcDimensionCount
:= IfcCurveDim(SELF)}
+horizontal
1..1
+curveGeometry
1
+segments
1..*
{ordered}
+axis 1..1

17. SRQ5: Ontologies for linking and mapping
“How can UML models of
geospatial information be
implemented as OWL
Ontologies, for linking and
mapping by applying Semantic
Web technologies?”
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Harmonization
GIS
Linking
BIM ITS
Harmonization
Harmonization

18. Fundamental differences
Closed World Assumption (CWA)
• The information model is
complete in the given context
• Additional or deviating
information is invalid
Open World Assumption (OWA)
• The information model presents
only what is currently known in
the given context
• Additional information extends
the model
Structure of information
Meaning of concepts
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19. Prototype experiment and validation
Prototype experiment:
• Extended UML profile for
OWL Encoding
– Global or shared properties
– Links to external concepts
– Implemented in the joint
approach (SRQ4)
• Adapted rules for modelling
and conversion
Prototype validation:
• Conversions for the studied issues
were improved by adding semantics
and modelling as suggested
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20. Level of information flow
Conversions of restrictions from
the CWA to the OWA must be
configured according to the
selected level of information flow:
1. Ontologies for use only in the
Semantic Web
2. Unidirectional information
exchange to the Semantic Web
3. Bidirectional information exchange
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21. SRQ4: A joint modelling approach
SRQ1
State
of
the
art
SRQ2 GIS-ITS
SRQ3 GIS-BIM
SRQ4 Harmonization
SRQ5 Ontologies and linking
Article 1 Article 5 CP1 SP3
Article 4 Article 5 SP4
Article 5 Article 1 Article 4
Article 2 Article 3 Article 4
Article 3
“How can information models
and semantics for
implementation technologies for
GIS, ITS and BIM be integrated
into a joint modelling approach?”
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22. Prototype experiment:
A structure of UML
Profiles for GIS, ITS
and BIM
«profile»
Core Geospatial Profile
Base profiles
Community conceptual profiles
General encoding profiles
Community encoding profiles
Legend
«merge»
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«profile»
OWL Encoding
«profile»
IFC EXPRESS Encoding
«profile»
GML Encoding
«profile»
DATEX II Conceptual
«profile»
IFC Conceptual
«profile»
DATEX II XML Encoding
«profile»
IFC XML Encoding
«profile»
Core Geospatial Profile
Base profiles
Community conceptual profiles
General encoding profiles
Community encoding profiles
Legend
«profile»
GDF Conceptual
«profile»
GDF MRS Encoding
«profile»
GDF XML Encoding
«merge»
«merge»
«merge»
«merge»
«merge»
«merge»

23. Prototype validation
• The structure could be implemented in UML sofware
• Existing and prototype models could be adapted
• Recommended actions:
– Revise UML profiles: ISO 19103 and ISO 19109
– Define formal UML profiles: ISO 19136 and ISO 19150-2
– Define encoding profiles: EXPRESS
– Define conceptual and encoding profiles: TPEG2
– Define mapping: DATEX II
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24. Conclusions - main contribution
• A joint approach for
information modelling
• Prototypes for profiles and
models within the harmonized
approach
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«profile»
OWL Encoding
«profile»
IFC EXPRESS Encoding
«profile»
GML Encoding
«profile»
DATEX II Conceptual
«profile»
IFC Conceptual
«profile»
DATEX II XML Encoding
«profile»
IFC XML Encoding
«profile»
Core Geospatial Profile
Base profiles
Community conceptual profiles
General encoding profiles
Community encoding profiles
Legend
«profile»
GDF Conceptual
«profile»
GDF MRS Encoding
«profile»
GDF XML Encoding
«merge»
«merge»
«merge»
«merge»
«merge»
«merge»

25. Conclusions
• Full harmonization not
appropriate
– Apply LinkSets for mapping
• Apply the joint modelling
approach for all three
domains
• Use common core concepts
– Data types from non-domain-
specific models
– Common concepts for geometry
and location referencing
Photo: Knut Opeide, Statens vegvesen
Harmonization
GIS
Linking
BIM ITS
Harmonization
Harmonization
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26. Similar representations
• Tobler’s first law of geography (Tobler, 1970):
– “everything is related to everything else, but near things are
more related than distant things”.
• Modernized to a digital world with multiple representations of the same
physical ”thing”:
– “every digital representation of a thing can be linked to any
other digital representation of the same thing, but links
between similar representations are more precise than links
between dissimilar representations”.
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27. Limitations and further research
• Limitation:
– Studied at a conceptual level,
need experiences from
implementations
• Further research:
– Common core concepts
– Use of OWL Ontologies
– Higher levels of interoperability
– Other application domains Photo: Knut Opeide, Statens vegvesen
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28. Knut Jetlund
Norwegian University of Science and Technology
Norwegian Public Roads Administration
knut.jetlund@vegvesen.no
Twitter: @Jetgeo
LinkedIn: https://www.linkedin.com/in/knut-jetlund/
Photo: Knut Opeide, Statens vegvesen
Thanks for
listening!
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