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Re: fast inferencing with jena and "?"

From: Leo Sauermann <leo@gnowsis.com>
Date: Fri, 01 Apr 2005 08:58:13 +0100
Message-ID: <424CFF15.9010405@gnowsis.com>
To: Yuzhong Qu <yzqu@seu.edu.cn>
CC: SWIG <semantic-web@w3.org>

combined approach.

it is things like "a - has value - X"
and "b - has value - Y"

and X - subclassof - Y

then they are "0.5" similiar.

if X == Y then they would be 1.0 similiar.

but our problems are much deeper,
like the filtered statement iterator of jena....


Es begab sich aber zu der Zeit 23.03.2005 02:52,  da Yuzhong Qu schrieb:

>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 Friday, 1 April 2005 07:58:36 UTC

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