Transcript Ontology management: Storing, Aligning and Maintaining

Ontology management: Storing, Aligning
and Maintaining Ontologies
2005. 1. 24
Changmin Choi
2015-07-17
Contents
• Requirement for Ontology Management
• Aligning Ontologies
• Supporting Ontology Change
• Organizing Ontologies
• Summary
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Requirement for Ontology Management(1/2)
• Ontology management
– Stored, aligned, evolution need to be
managed
• Alignment
– the ontologies either need to be integrated
– Because, re-used
• Ontology alignment is very relevant in
a Semantic Web context
– separate ontologies should be aligned and
linked
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Requirement for Ontology Management(2/2)
• Support for evolving ontologies
– change in the real world
– adaptations to different tasks
– alignments to other ontologies
• Ontology library systems
– grouping, reorganizing ontologies for
further re-use
– integration, maintenance, mapping,
versioning
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Aligning Ontologies(1/5)
• Why is Aligning Needed
– created to link different terminologies
– modeling styles used in these domain
specific ontologies
– creating bridges between separated pieces of
knowledge
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Aligning Ontologies(2/5)
• Aligning Annotated XML Documents
(The alignments)
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Aligning Ontologies(3/5)
• RDF transformation(RDFT)
– Class
– Bridge
• ValueCorrespondence
– Map
• DeclarativeMap
• ProcedureMap
(RDFT class diagram)
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Aligning Ontologies(4/5)
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(The alignments)
(RDFT class diagram)
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Aligning Ontologies(5/5)
• BridgeSource to BridgeTargets
– class-def BridgeSources
slot-constraint rdft_set_member has-value SourceClass
– class-def BridgeTargets
slot-constraint rdft_set_member has-value TargetClass1
slot-constraint rdft_set_member has-value TargetClass2
slot-constraint rdft_set_member has-value TargetClass3
• Mapping in OIL
– Statements over the bridges need to be specified
as statements over OIL
– Very useful because allows to invoke an inference
engine to perform knowledge-level validation of
the bridges
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Supporting Ontology Change
(1/4)
• Ontologies specific
– Not static, evolution is need
• Reasons of changes in ontologies
– Changes in the domain
• Change in the real world
• Domain to be modified
– Changes in the conceptualization
• Different perspective
• Ex) traffic connection : road, cycle-tracks,
canals, bridges..etc
– Changes in the specification
• Translation – retain the semantics
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Supporting Ontology Change
(2/4)
• Changes in ontologies involve Several
Problems (1/2)
– Effects of Ontology Change
• Different interpretation or may use unknown
terms
• Changes to the source ontology
• Applications that use the ontology may also be
hampered
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Supporting Ontology Change
(3/4)
• Changes in ontologies involve Several
Problems (2/2)
– Typical changes and their Specification
• Standards tend to change very often.
• Ex) http://eccma.org/UNSPSC
– 16 updates between 31 January 2001 and 14
September 2001
– Each update contained between 50 and 600 changes
– In 7.5 months, more than 20% of the current
standard is changed
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Supporting Ontology Change
(4/4)
• Change Management
– Comparing Ontologies
•
•
•
•
•
Non-logical change
Logical definition change
Identifier change
Addition of definitions
Deletion of definitions
– Specification of Change
• Transformation or actual change
• Conceptual relation
• Descriptive meta-data like date, author, and
reason of the update
• Valid context
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Organizing ontologies
(1/11)
• Different ontologies increasing
– Task of storing
– Maintaining and re-organizing
• Ontology library system
– Tool in grouping and re-organizing
ontologies
– Re-use, integration, maintenance, mapping
and versioning
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Organizing ontologies
(2/11)
• Sesame Requirements
– Open storage, identification and versioning
of ontologies
– Smooth access to existing ontologies and
advanced support in adapting ontologies to
certain domain and task-specific
circumstances
– Fully employing the power of standardization
and providing access to upper-layer
ontologies and standard representation
languages
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Organizing ontologies
(3/11)
• Sesame Requirements
(Aspects of an ontology library system)
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Organizing ontologies
(4/11)
• Functionality of an Ontology Storage
System (1/3)
– Management
• Storage
– easily accessible
– Ontologies classified
– Stored in modules(because ontology re-use)
• Identification
– Unique identifier
• Versioning
– Ensuring consistency
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Organizing ontologies
(5/11)
• Functionality of an Ontology Storage
System (2/3)
– Adaptation
• Searching
– how to search ontology
• Editing
– how to add, delete and edit specific ontologies
• Reasoning
– How to derive consequences from an ontology
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Organizing ontologies
(6/11)
• Functionality of an Ontology Storage
System (3/3)
– Standardization
• Language
– Kind of standard ontology language used in the
ontology library system
– Ex)RDFS, XMLS, DAML+OIL
– Upper-level Ontologies
• ‘grounded’
• Ex) Upper Cyc Ontology, SENSUS, MikroKosmos,
PENNMAN Upper Model, IEEE upper-layer
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Organizing ontologies
(7/11)
• Current storage systems
– Management
• Storage
– Client/server-based architecture
– Web-accessible architecture
• Identification
– Standard way to identify an ontology is by its
Unique name or Identifier
• Versioning
– Only SHOE supports versioning for handling the
dynamic changes of ontologies
• Sesame
– Client/server-based architecture and supports
web access
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Organizing ontologies
(8/11)
• Current storage systems
– Adaptation
• Searching
– Access through the Internet or World Wide Web
– Offer Simple browsing only
– SQL-based searching
• Editing
– Simple editing function
• Reasoning
– Very simple reasoning function
– Ex) WebOnto(rule-based reasoning), Ontolingua
(ontology testing), SHOE(ontology revision)
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Organizing ontologies
(9/11)
• Current storage systems
– Standardization
• Language
– Different language to store their ontologies
– Inter-language translating(like Ontolingua)
• Upper-level Ontology
– IEEE SUO
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Organizing ontologies
(10/11)
• Requirement for a Storage System
– Management
• Storage
– Client/server-based architecture& Web accessible
• Identification
– Unique ontology URL
• Versioning
– Only SHOE
– Adaptation
• Searching and editing
– Visualized browsing environment
– Using hyperlinks
• Reason
– Simple reasoning included ontology creation,
mapping and integration
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Organizing ontologies
(11/11)
• Requirement for a Storage System
– Standardization
• Language
• Upper-level ontology
– Ontolingua, IEEE SUO
– Other requirements
• Ontology scalability
• Maintenance facility
• Explicit documentation
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Summary
• Alignment is important
– Several ontologies of a domain used for a
specific task
• Ontologies not static
– Domain changes
– Adaptations to different task
• Consider
– Survey exiting system
– Wish-list for the ideal ontology library
system
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