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Re: fast inferencing with jena and "?"

From: Yuzhong Qu <yzqu@seu.edu.cn>
Date: Wed, 23 Mar 2005 09:52:34 +0800
Message-ID: <005a01c52f4a$fbccde40$fd0b77ca@xobjects>
To: "Leo Sauermann" <leo@gnowsis.com>
Cc: "SWIG" <semantic-web@w3.org>
This kind of matching problem is hard.

BTW,

Your Schema S is based-on OWL Lite, OWL DL or RDF(S)?

Which kinds of  similarity do you consider?

Linguistics similarity (enhanced with WordNet)

Structural simularity (enhanced with inference capability)

Or a combined approach.


Yuzhong Qu

----- Original Message ----- 
From: "Leo Sauermann" <leo@gnowsis.com>
To: "Dave Reynolds" <der@hplb.hpl.hp.com>
Cc: <semantic-web@w3.org>
Sent: Wednesday, March 23, 2005 12:58 AM
Subject: Re: fast inferencing with jena and "?"


> 
> Hi Dave,
> 
> actually a colleague of me is doing it and it is a commercial project we 
> do for a telecommunications company, so we can't publish the triples :-|
> 
> roughly, its about checking if two graph A, B are "near" to each other,
> A,B describe resources and the resources are of Schema S
> now what we do is complete A and B by using S and then doing some graph 
> matching algorithm combined with property matching,
> so we combine A with S and B with S and then use A(S) and B(S) to do the 
> matching.
> 
> like
> if type(A(S)) == type(B(S)) then "quite match"
> and forallPropertiesOf( prop(A(S)) == prop(B(S))) then add "quite match"
> ...
> 
> so there are  a few find(spo) that fire into the graph which the graph 
> does not like
> 
> we'll try the new Jena release and see what happens.
> 
> regards
> Leo
> 
> Es begab sich aber zu der Zeit 21.03.2005 12:16,  da Dave Reynolds schrieb:
> 
> >
> > Hi Leo,
> >
> >> The problem with Jena is: the Model RDFS_MEM_TRANS_INF is too slow to do
> >> simple inference (and it was the fastest we found in jena)
> >
> >
> > Which version of Jena? There was a bug fix affecting TRANS between 2.1 
> > and 2.2beta1 and a performance problem fixed between 2.2beta1 and 
> > 2.2beta2.
> >
> >> It has 200ms performance of matching two small rdf instance models
> >> against a RDF/S ontology model (180 classes). 
> >
> >
> > What do you mean by "matching" a model against an RDFS model?
> >
> > If you can show us what you are doing (ideally a self-contained code 
> > example) then we might be able to advise on optimizations. Though code 
> > exchange is probably better done over on jena-dev or off list.
> >
> >> We did everything we could to make it faster, including prefetching all
> >> classes, properties, trying out different Jena inferencers, etc.
> >
> >
> > If you prefetched all classes and properties then there is presumably 
> > no inference left. If the performance wasn't good enough in that set 
> > up then you don't need faster inference you need a faster algorithm or 
> > reduced API overheads. That would make it even more interesting to see 
> > exactly what you are doing to figure where the performance problem is.
> >
> > Cheers,
> > Dave
> >
> >
> 
> 
> 
> 
Received on Wednesday, 23 March 2005 01:49:32 UTC

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