We propose a tool to manage several sorts of relationships among RDF and RDFS. Our tool consists of three main functions: graphical editing of RDF contents, graphical editing of RDFS contents, and meta-model management facility. Metamodel management facility supports maintenance of relationship between RDF and RDFS contents. The above facilities are implemented based on plug-in system. We provide basic plug-in modules for consistency checking of RDFS classes and properties. The prototyping tool, called MR^3 (Meta-Model Management based on RDFs Revision Reflection), is implemented by Java language. Through the experiment of using MR^3, we show how MR^3 contributes the Semantic Web paradigm from the standpoint of RDFs contents management.
MR^3: Meta-Model Management based on RDFs Revision Reflection
1. MR3: Meta-Model Management
based on RDFs Revision Reflection
Takeshi Morita1), Noriaki Izumi2),
Naoki Fukuta1), Takahira Yamaguchi3)
1) Shizuoka University, Japan
2) CARC, National Institute of AIST, Japan
3) Keio University, Japan
5. RDF (Resource Description Framework)
subject （Resource）
predicate （Property）
object （Resource）
hasFather
Statement
Model Personrdf:type
William
RDF: Framework for representing information on the Web
object （Resource）
Charles
Syntax (XML)
<rdf:Description about=“William”>
<hasFather rdf:resource=“Charles”/>
<rdf:type resource=“Person”/>
</rdf:Description>
Resource
Property
Resources are all things being described
by RDF expressions
A property is a relation between resources.
6. RDFS (RDF Vocabulary Description Language,
RDF Schema )
<rdf:Class rdf:about=“Person”>
<rdfs:subClassOf resource=“&rdfs;Resource”/> </rdf:Class>
<rdf:Property rdf:about=“hasFather”></rdf:Property>
Syntax (XML)
Model (The Same Model as a RDF Model)
hasFather rdf:Property
rdf:type
Person
rdfs:Classrdf:type
rdfs:Resource
rdfs:subClassOf
Class
Property
: Groups of related resources
: relationships between resources Meta-Model
RDFS
=
provides mechanisms for describing RDFS class and property
7. Issues
Because RDF is described by XML, it’s difficult
to build up RDF contents manually.
The main function of conventional tools is to display
XML based contents with RDF data model.
There still remains an issue as a difficulty of looking
the whole structure of both RDF and RDFS contents .
9. Our Goal
<rdf:RDF xmlns:rdfs=“…rdf-syntax-ns”>
<image rdf:about="http://...">
<title>…</title></image>…
</rdf:RDF>
<rdf:RDF xmlns:rdfs=“…rdf-schema#">
<rdfs:Class rdf:about="http://purl.org/rss/1.0..."
<rdf:Property rdf:about="http://purl.org/rss/1.0..."
</rdf:RDF>
Class Property
Property
RDFS Document
RDF Document RDF Data Graph
RDFS Data Graph
(2)
(2) Graphical Editor of RDFS contents
(1) Graphical Editor of RDF contents
(1)
(3) Meta-Model Management Facilities
(3)
LiteralResource
10. Contents
Motivation
Concept of Meta-Model Management
Meta-Model Management
Meta-Model Management Facilities
Meta-Model Management Facilities examples
Implementations
Case Study
Conclusions
11. Meta-Model Management
authorPerson
RDFS Class RDFS Property
Meta-Model (RDFS)
author
Model (RDF)
Book
Book Person
The type of Resource
Resource Resource
RDF Property
rdfs:Resource rdf:Property
Crime and Punishment F.M. Dostoevsky
RDF (Model) and RDFS (Meta-Model) can be managed
separately and maintained their relationships automatically.
12. Meta-Model Management Facilities
Change RDFS Class and Property
Removal of RDFS Class and Property
Change the Type of RDF Resource and RDF
Property
Change the RDFS class name referred before the
user replace the type of an RDF resource
Make a new RDFS class which is not defined
The same is said of an RDF property
Import RDF File
etc
Modifying RDF and RDFS
Consistency checking of
classes and properties
14. Book
Book
Book
Biblio
Biblio
Meta-Model Management Facilities example （2）
Change the type of an RDF Resource
author
RDF
Person
author
RDFS
Biblio
rdfs:Resource
authorPerson
rdf:Property
Crime and Punishment
F.M. Dostoevsky
The Brothers Karamazov
17. Graphical Modeler of MR3
Editor Windows Sub Windows
Class Editor Property Editor
RDF Editor
Attribute Dialog
Namespace Table
18. Movie
Three examples in Meta-Model Management Facilities
Change RDFS class
Change RDFS property
Change the type of an RDF Resource
Export RDF Model as XML Syntax
20. Case Study
Purpose
To check that MR3 can separate and display RDF and
RDFS elements appropriately
Comparative Software
IsaViz
Popular tooｌ to build up RDF contents
World Wide Web Consortium offers
Visualize RDF and RDFS model similarly
Input Document
Creative Commons Schema and CC-GNU GPL (Mixed
RDF and RDFS)
Creative Commons is devoted to expanding the range of creative
work available for others to build upon and share.
http://creativecommons.org/
Creative Commons Schema is vocabularies to make metadata
about License
Software, Music, Movie, …
The CC-GNU GPL adds the Creative Commons' metadata and
Commons Deed to the Free Software Foundation's GNU General
Public License.
Commons Deed:
a human readable version of the license
<?xml version="1.0" encoding="SHIFT_JIS"?>
<rdf:RDF xmlns="http://web.resource.org/cc/"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<Work rdf:about="">
<license rdf:resource="http://creativecommons.org/licenses/GPL/2.0/" />
<dc:type rdf:resource="http://purl.org/dc/dcmitype/Software" />
</Work>
<License rdf:about="http://creativecommons.org/licenses/GPL/2.0/">
<permits rdf:resource="http://web.resource.org/cc/Reproduction" />
<permits rdf:resource="http://web.resource.org/cc/Distribution" />
<requires rdf:resource="http://web.resource.org/cc/Notice" />
<permits rdf:resource="http://web.resource.org/cc/DerivativeWorks" />
<requires rdf:resource="http://web.resource.org/cc/ShareAlike" />
<requires rdf:resource="http://web.resource.org/cc/SourceCode" />
</License>
<rdfs:Class rdf:about="http://web.resource.org/cc/Agent">
<rdfs:subClassOf>
<rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-
schema#Resource"/>
</rdfs:subClassOf>
<dc:title>agent</dc:title>
<dc:description>
something (e.g. a person, corporation or computer) capable of creating
things<
/dc:description>
</rdfs:Class>
…..
Creative Commons' metadata (RDF/XML)
# Resources 30, # Literals 17, # Statements 64
21. Case Study: IsaViz
RDFS
+
RDF
It’s difficult for a user to understand
hierarchical relations of RDFS elements.
Class
hierarchy
Property
hierarchy ?
23. Discussion
A user can understand the graph of MR3
easier than IsaViz
RDF and RDFS elements are separated
Hide unnecessary elements for the user
Properties of RDFS model (such as “rdfs:domain”,
“rdfs:range”, “rdfs:comment”, …) and those values
rdf:type property and that value
The result of comparison between IsaViz and MR3
25. Conclusions
We have developed a meta-model management tool
for RDFs Contents
We have checked that MR3 can separate and
display RDF and RDFS elements appropriately
Future work
We’d like to make RDFs contents by MR3 and
check usefulness of meta-model management
facilities.
