Transcript Metadata Representation, Knowledge Representation, and

Metadata Representation,
Knowledge Representation,
and Ontologies Section
Line Pouchard
Oak Ridge National Laboratory
What makes the Semantic Grid
different from the Semantic Web
(according to Line)
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SG is focused on the needs of applications
that use Grid technologies in various
context.
These tend to be scientific applications from
scientific domains whose needs are quite
different from those of typical web users.
But they all use the Web in various clunky,
home grown packages.
So the SG is focused on developing bridges,
leveraging and cross-cutting technologies
from the SW and assess them for scientific
applications.
Drivers (Line and Jim)
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Need to share context-dependent data across
community(ies) (data dissemination/discovery)
Support mapping between data models (across
domains, over time)
Managing non-hierarchical data relationships /
multiple hierarchies at once
Describing hypothesis/statements of trust
/reification (statements about other statements)
Numerous XML schemas and DTDs, most are
domain, or even application specific.
More drivers
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Mechanisms for re-use, mediation, aggregation,
semantic federation are needed.
Needs for ontology repositories, discovery and
capturing tools
Granularity of ontologies
Applying semantic stuff to large data/complex
workflow/distributed independent contributors
Maintaining links between data and ontologies,
evolving schemas, …
Languages
RDF, RDFS, OWL descriptions:
gather in one place a description of the
characteristics of each language
 comparison, including when to use
each. Some of this already exists but
needs updating and gathering.
 For instance,
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More on languages
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Collection of assertions and triples, properties
Range and domain of the triples
Equivalences
Booleans
Restrictions on classes and properties
Cardinality
class properties
Other possible languages (there are some!):
PSL, Ontolingua, KIF, etc..: what is suitable, not
suitable for the semantic grid and why.
Existing Grid technologies that
can potentially be enhanced by
SG:
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These would include the ones that we think
are the most receptive to the work
performed on SG.
It should make a clear case for why each
Grid technology presented here would
benefit from semantic grid technologies, for
metadata and knowledge representation,
ontologies, etc…. and where.
Here are just a few bullets:
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Metadata Catalog Services
OGSI service description
WS-Resource Framework
Data Format Description Language