PREMIS OWL

sounderslipInternet and Web Development

Oct 22, 2013 (4 years and 22 days ago)

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ELIS


Multimedia Lab

PREMIS OWL



Sam Coppens

Multimedia Lab

Department of Electronics and Information Systems

Faculty of Engineering

Ghent University


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Survey


Quick intro in semantic web



Why PREMIS OWL?



Design



Example



Conclusion


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INTRO
SEMANTIC

WEB

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XML / XSD

Metadata in XML


<author>

<uri>page</uri>

<name>Ora</name>

</author>

<
document>

<details>


<uri>href="page"</uri>


<author>



<name>Ora</name>


</author>

</details>

</document>


<document href="page">


<author>Ora</author>

</document>


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XML / XSD

XML problem:


<x>

<y>page</y>

<z>Ora</z>

</x>

<
x>

<y>


<z>href="page"</z>


<v>



<w>Ora</w>


</v>

</y>

</x>


<x href="page">


<y>Ora</y>

</x>


?

?

?

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XML / XSD

?

?

?

?
Structure

?
meaning

Tags

XML Schema

!
Exchange
Format

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Semantic Web technologies


Technologies developed by the World Wide Web Consortium (W3C)



Goal: make the Web a universal medium for data, information and
knowledge exchange



HTML, XML
-
> RDF, RDFS, OWL, …

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RDF


RDF (Resource Description Framework)


Triples: subject


predicate


object


URI to identify resources


“The author of the note is Tim”






Serialisatie in XML:


<rdf:RDF xmlns:rdf=
http://www.w3.org/1999/02/22
-
rdf
-
syntax
-
ns#
>



<Note rdf:about=
http://www.example.org/#note
>


<hasAuthor rdf:resource="http://www.example.org/#Tim”/>


</Note>


</rdf:RDF>


Note

Tim

hasAuthor

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RDFS


RDF Schema


Standardised terms to describe concepts


Introduces classes and instances










Subclasses, subproperties


Hierarchy!

Note1

Tim

hasAuthor

Class
Note

Class

Person

rdf:type

rdf:type

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OWL


Web Ontology Language, W3C recommendation (2004)


Richer vocabulary


Defines advanced relations


Data
-
typing


Cardinality


Rich typing van properties





Example:





Reasoning!




complex ontologies

Note1

Tim

hasAuthor

Class
Note

Class

Person

type

type

isAuthorFrom

<owl:ObjectProperty rdf:ID=“
isAuthorFrom
”>


<owl:inverseOf rdf:resource=“#hasAuthor”>

</owl:ObjectProperty>

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Ontology (described in OWL)

subClassOf

Birth date

DatatypeProperty

Class:
Person

Class:
Scientist

Individual

Birth date

“14/10/1801”

OWL
-
constructions



Class



DatatypeProperty



subClassOf



Individual





“Joseph Plateau”

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Semantisch Web


SPARQL Protocol And RDF Query Language (SPARQL)


SQL like language for RDF


Example: search all texts of Tim


SELECT ?x WHERE ?x hasAuthor Tim

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WHY

PREMIS OWL?

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Why PREMIS OWL?


Changing Technologies




World Wide Web




Semantic Web



XML






RDF, RDFS and OWL

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Semantic Web


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Why PREMIS OWL?


Data model of PREMIS:







Dynamically relating the


Five entities to each other.




XML: identifiers are used for modelling the relations.




directed and not bidirectional!


OWL: resources are identified by a URI




direct relations between the entitities



(bidirectional by using inverse relations)

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DESIGN

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Design


Design decisions:



Stick as close as possible to the PREMIS 2.0 Data Dictionary.



No information loss when migrating PREMIS XML


PREMIS OWL

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Design


Changes:




Every XML wrapper has become a class.


Object has 3 subclasses: File, Bitstream,
Representation.


Relations between the entities.


Linking to SKOS vocabularies.


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Design


Object has 3 subclasses: File, Bitstream, Representation







Subclasses based on the objectCategory property
(“Bitstream”, “File”, “Representation”)

Object

Bitstream

File

Representation

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Design


Relations between the entities:


Every entity has become a class.


Every entity has a URI.



No need for using the entities’ identifiers for relating
them.

This URI is used for relating the different entities.




object properties and their inverse properties


Object

Identifiers

Event

Sam Coppens @iPres2010 PREMIS Implementation Fair: PREMIS OWL

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Design


Relations between the entities:


Every entity has become a class.


Every entity has a URI.



No need for using the entities’ identifiers for relating
them.

This URI is used for relating the different entities.




object properties and their inverse properties


Object

Identifiers

Event

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Design


Linking to SKOS vocabularies:



event types vocabulary (eventType)


preservation level role vocabulary
(preservationLevelRole)


message digest algorithm vocabulary
(messageDigestAlgorithm)




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EXAMPLE

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Example

Based on the louis example:



http://www.loc.gov/standards/premis/louis
-
2
-
0.xml


PREMIS OWL example (serialised in N3 notation):



https://docs.google.com/leaf?id=0BxtLo
-
HRghbvZWFjZmMwN2MtNTMyZS00NzY3LThmNzktMzMwY
mFhZGM1N2Yx&sort=name&layout=list&num=50


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Example

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Mets

Tiff

Image 2

Tiff

image 1

JPEG image 1

JPEG Image 2

Validation

Validation

Ingestion

Ingestion

Migration

Migration

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Conclusion

Sam Coppens @iPres2010 PREMIS Implementation Fair: PREMIS OWL



Ternary relations remain problematic in OWL


identifiers




Publication of the provenance information is not the primary concern
of PREMIS OWL.




PREMIS = provenance metadata + technical metadata +



rights metadata




Provenance metadata will become more important in the


future. There are provenance models much more


suited for interoperability and publication on het Web.



W3C Provenance Incubator Group




PREMIS OWL:


http://mulitmedialab.elis.ugent.be/users/samcoppe/ontologies/Premis/pr
emis.owl