Hi Pantelis,

There is no problem of parsing OWL-DL with Jena models (recall OWL-DL is a
valid RDF) , different than OntModel.

You will only loose some convenient methods and classes in Jena, but you can
still check if a class has certain rdf:type or certain properties.  I agree
the client code might became less elegant , but performance gain may worth
it.


On Wed, Oct 6, 2010 at 6:08 PM, chung <chvng at mail.ntua.gr> wrote:

> Hi Nina, Egon,
>   That would be an interesting experiment in general but there are some
> technical problems related to ToxOtis and to the current format of our
> RDF documents. First of all, a common RDF specification has been chosen,
> that is OWL-DL and we have lots of times striven to stick to it. ToxOtis
> produces OWL-DL compliant RDF representations for every OpenTox entity
> (methods asIndividual(OntModel):Individual and asOntModel():OntModel ).
> OntModel and OntClass have been chosen as the prime Jena objects to work
> with in ToxOtis and in YAQP, our web application also. Apart from the
> fact that it would be hard to change that, I also reckon we shouldn't
> for various reasons I'll try to summarize.
>


  OntModel is an interface that offers lots of functionalities such as
> creation of Annotation, Datatype and Object Properties that are missing
> from the interface Model where one can just use m.createProperty(String)
> to create an untyped property. Additionally, OntModel is tightly
> connected to OntClass, an interface used to describe the ontological
> classes to which instances are binded. So if we need to produce OWL-DL
> compliant representations we either need an implementation of OntModel
> and OntClass provided by Jena or one of ours. My opinion is that the
> adoption of OWL-DL against OWL-Full or OWL-Lite does not increase
> significantly the size of the representation. What is more, OWL-DL
> guarantees computability and decidability and does not oblige users to
> use some inference engine that imposes overhead so it would be better to
> cling to it both for the server and from the client side.
>   As you already know, using OntModel we have performed measurements to
> compare between different specifications and it was shown that OWL-DL
> performs better for parsing documents compared to OWL and OWL-Lite. What
> might be of interest is to reveal the impact of the cache size (for in
> memory triple storage) on the performance of RDF parse/serialization
> procedure and on the allocation of resources.
>
> Best Regards,
> Pantelis
>
> On Wed, 2010-10-06 at 15:12 +0200, Egon Willighagen wrote:
>
> > Pantelis,
> >
> > On Wed, Oct 6, 2010 at 2:58 PM, Nina Jeliazkova
> > <jeliazkova.nina at gmail.com> wrote:
> > >> Would it be hard for you to switch to "plain" RDF (i.e.  omit all
> > >> RDF:type statements) and compare computation times with OWL
> > >> representations.
> > >
> > > From dataset service point of view it is practically impossible,
> without
> > > breaking everything,  but form client point of view one can try using
> Jena
> > > models, different than OntModel.
> >
> > what happens if you use either of these:
> >
> > ModelFactory.createDefaultModel()
> > ModelFactory.createNonreifyingModel()
> >
> > ?
>
>
> If you think this is necessary, we can set up an experiment without
> ToxOtis...
>


Yes, please (unless it is a month work...)

Best regards,
Nina




>
> >
> > Egon
> >
>
>
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