be sure to check this too: http://www.image.ece.ntua.gr/papers/684.pdf + http://image.ntua.gr/~achort/rapid.zip
If something significant comes out of your study, it would be really nice to publish/blog/discuss it. On Thu, May 23, 2013 at 1:31 PM, Bahador(reza)? OFOGHI <[email protected]>wrote: > Thanks so much Olivier, I need to go and experiment with these. will let > you and others know what works best for this problem. > > BO > > Bahador(reza)? OFOGHI, PhD > Major: Information Technology > > > > ________________________________ > From: Olivier Rossel <[email protected]> > To: [email protected]; Bahador(reza)? OFOGHI <[email protected]> > Sent: Thursday, 23 May 2013 8:05 PM > Subject: Re: Owl Ontology and TDB Individuals > > > While browsing the net, I just read that REQUIEM is an attempt by the OWL2 > gurus to develop a query rewriter. > http://www.cs.ox.ac.uk/isg/tools/Requiem/ > > Sounds uber cool. > I would definitely appreciate any feedback about that tool. > > > On Thu, May 23, 2013 at 10:45 AM, Olivier Rossel > <[email protected]>wrote: > > > in that case, you need some inference at one time or another. > > two strategies: > > Strat 1: materialize the infered triples[1], inject in the DB, and then > > query with the regular SPARQL engine (:ok for very small datasets, and > > slow-changing data). for reasonably big data, you can use the OWL2-RL > > subset of OWL2. as far as i know, an implementation of OWL2-RL exists > with > > drools, and you can play with it in protege or eulerGUI. > > Strat 2: rewrite the query according to the data structure and run on > > your existing dataset (:the current trade off for big data on top of > OWL). > > for that, you must use the OWL2-QL subset of OWL2. DBs such as stardog > or > > OWLIM handle such query rewriting, i do not know if fuseki has such a > query > > rewriter. > > > > as far as i understand, this is the global picture of OWL2+RDF. > > i let the local gurus correct the above statements. > > > > > > [1]: in our example, one infered tripe would be :DATA rdf:type :C > > > > > > On Thu, May 23, 2013 at 1:53 AM, Bahador(reza)? OFOGHI < > > [email protected]> wrote: > > > >> Yes, I would like to retrieve :DATA since in myOntology, there is this > >> subClassOf relationship that can be traveresed by the reasoner. > >> > >> thanks. > >> BO > >> > >> > >> ________________________________ > >> From: Olivier Rossel <[email protected]> > >> To: [email protected]; Bahador(reza)? OFOGHI <[email protected]> > >> Sent: Wednesday, 22 May 2013 6:54 PM > >> Subject: Re: Owl Ontology and TDB Individuals > >> > >> > >> Let's take an example to clarify. > >> > >> myOntology.owl: > >> :SC rdfs:subClassOf :C > >> > >> myData.rdf: > >> :DATA rdf:type :SC > >> > >> You want to retrieve all resources of type :C > >> So you craft a SPARQL query for that: > >> SELECT * WHERE {?s rdf:type :C} > >> > >> Do you expect such a query to return :DATA, or not? > >> > >> > >> On Wed, May 22, 2013 at 12:47 AM, Bahador(reza)? OFOGHI < > >> [email protected] > >> > wrote: > >> > >> > Inference would be on concepts and based on the relationships between > >> > them. Data will then be fecthed accordingly since they are instances > of > >> the > >> > concepts, isn't it? I am not aware of whether it is generally possible > >> to > >> > do inference on data. > >> > > >> > > >> > Bahador(reza)? OFOGHI, PhD > >> > Major: Information Technology > >> > > >> > > >> > > >> > ________________________________ > >> > From: Olivier Rossel <[email protected]> > >> > To: [email protected]; Bahador(reza)? OFOGHI <[email protected] > > > >> > Sent: Tuesday, 21 May 2013 10:16 PM > >> > Subject: Re: Owl Ontology and TDB Individuals > >> > > >> > > >> > Is it inference on data themselves? Or on concepts only? > >> > > >> > > >> > On Tue, May 21, 2013 at 11:54 AM, Bahador(reza)? OFOGHI < > >> > [email protected] > >> > > wrote: > >> > > >> > > Thanks Olivier, > >> > > > >> > > In fact, I do need to make use of inference in the OWL ontology. > This > >> is > >> > a > >> > > big ontology (being merged with some other ontologies) only one part > >> of > >> > > which is the names I have described. In this case, would you/anyone > >> else > >> > > have any ideas how I might be able to get this done. > >> > > > >> > > thanks again > >> > > Bahador > >> > > > >> > > > >> > > > >> > > ________________________________ > >> > > From: Olivier Rossel <[email protected]> > >> > > To: [email protected]; Bahador(reza)? OFOGHI < > [email protected] > >> > > >> > > Sent: Tuesday, 21 May 2013 7:42 PM > >> > > Subject: Re: Owl Ontology and TDB Individuals > >> > > > >> > > > >> > > Basically, you do not have to load both the OWL and the RDF in the > DB. > >> > > Such a RDF: > >> > > :nameNumberOne a :NAME. > >> > > :nameNumberOne :has_a :namePartNumberOne . > >> > > :nameNumberOne :has_a :namePartNumberTwo . > >> > > > >> > > will load just fine in Fuseki. > >> > > You can then query it without having to load the OWL in the DB. > >> > > (RDF databases are mostly schemaless). > >> > > > >> > > The OWL is here just to be understood by the domain expert who > >> > > creates the query. > >> > > > >> > > (Note: in an inference-aware DB, it *is* interesting to load both > the > >> OWL > >> > > and the RDF together, but I do not think you have the need for > >> > inference). > >> > > > >> > > > >> > > On Tue, May 21, 2013 at 3:22 AM, Bahador(reza)? OFOGHI > >> > > <[email protected]>wrote: > >> > > > >> > > > THanks Andy and David, > >> > > > > >> > > > I have now looked at this and I still have questions! > >> > > > > >> > > > 1- when you say transactions will not work across a mixture of > >> graphs > >> > in > >> > > a > >> > > > dataset, does that mean that I will not be able to query and/or > use > >> > > > reasoners on this dataset? > >> > > > 2- if not, then what would be the best solution to keep an RDF/XML > >> > > > ontology which will have thousands of individuals? I would have > >> > thought I > >> > > > could create the structure ontology (the OWL file) and keep it > >> separate > >> > > > from the data file (as in TDB) that will be assigned to the OWL > >> > ontology > >> > > > nodes. I am new to this field and I appreciate any hints. > >> > > > > >> > > > To make it more clear or refresh your memory, here is the problem > I > >> am > >> > > > trying to solve: > >> > > > > >> > > > I have created an ontology in OWL somewhere in which I have a node > >> > named > >> > > > NAME which includes subparts of the name in NAME_PART1, ..., > >> > NAME_PARTn. > >> > > I > >> > > > have a large CSV data file that has (many) records of names and > the > >> n > >> > > name > >> > > > parts. I will have to convert the CSV file into an RDF dataset > >> (which I > >> > > > will find a way for, should not be too complicated). Then, I need > to > >> > > make a > >> > > > connection between the RDF dataset of these records and the OWL > >> > ontology > >> > > > that keeps the relationships between the concept nodes, e.g., NAME > >> > has_a > >> > > > NAME_PART1. > >> > > > > >> > > > Given that I have the two OWL and RDF files ready, what would I > >> have to > >> > > do > >> > > > next to be able to query over the NAMEs and NAME_PARTs. What does > it > >> > take > >> > > > to glue the two files? > >> > > > > >> > > > kind regards, > >> > > > Bahador > >> > > > > >> > > > > >> > > > > >> > > > ________________________________ > >> > > > From: David Jordan <[email protected]> > >> > > > To: "[email protected]" <[email protected]> > >> > > > Sent: Thursday, 16 May 2013 5:13 AM > >> > > > Subject: RE: Owl Ontology and TDB Individuals > >> > > > > >> > > > > >> > > > OK, now with your clarification it makes sense to me and is what I > >> > > > expected. > >> > > > > >> > > > > >> > > > -----Original Message----- > >> > > > From: Andy Seaborne [mailto:[email protected]] > >> > > > Sent: Wednesday, May 15, 2013 3:03 PM > >> > > > To: [email protected] > >> > > > Subject: Re: Owl Ontology and TDB Individuals > >> > > > > >> > > > On 15/05/13 18:47, David Jordan wrote: > >> > > > > Andy, Please clarify something. In this reply, you state * Put > the > >> > > > > ontology in one named graph and the individuals in another one, > or > >> > the > >> > > > > default graph, and hence in the same database? * You can put a > >> single > >> > > > > graph from TDB into a general dataset or just work with that one > >> > graph > >> > > > > (transactions will not work across a mixture of graphs in a > >> dataset). > >> > > > > > >> > > > > You then reference the online docs that state: It is possible to > >> use > >> > > > > just one of the graphs from the dataset. A common way of working > >> with > >> > > > > one graph is to use the default graph of the dataset. > >> > > > > >> > > > > >> > > > Dataset dataset = DatasetFactory.createMem() ; > >> > > > Dataset tdb = TDBFactory.createDataset() ; > >> > > > > >> > > > // Pick one graph/model out of the dataset. > >> > > > Model m1 = tdb.getNamedModel("http://example/tdb/graph";) > ; > >> > > > dataset.addNamedModel("http://example/individuals";, m1) > ; > >> > > > > >> > > > // A model with completely different storage > >> > > > Model m2 = ModelFactory.createDefaultModel() ; > >> > > > dataset.addNamedModel("http://example/ontology";, m2) ; > >> > > > > >> > > > ... a dataset with a mix of model storage implementations. > >> > > > > >> > > > > > >> > > > > My code uses the interface com.hp.hpl.jena.query.Dataset. It > >> allows > >> > me > >> > > > > to start/stop transactions and to access named models. I can > >> access > >> > > > > multiple named models. Isn't a model a graph in the database? > >> > > > > Isn't a graph == model == graph ? You say that "transactions > will > >> not > >> > > > > work across a mixture of graphs in a dataset". So a given > >> > > > > com.hp.hpl.jena.query.Dataset object, while it can return > multiple > >> > > > > named Models, you cannot use them in the same transaction? > >> > > > > >> > > > then > >> > > > > >> > > > dataset.begin(ReadWrite.READ) ; > >> > > > > >> > > > ==> exception. "Transactions not supported" > >> > > > > >> > > > > When you said "a general dataset", are you referring to the > >> default > >> > > > > model/graph, which is stored in a triple table in SDB and > >> essentially > >> > > > > is using the single default graph managed by TDB/SDB? > >> > > > > >> > > > The kind of dataset returned by DatasetFactory.createMem() > >> > > > > >> > > > > Some of the wording used, both in the documentation and in your > >> > reply, > >> > > > > seem vague to me, with multiple interpretations. I don't believe > >> the > >> > > > > single sentence "It is possible to use just one of the graphs > from > >> > the > >> > > > > dataset." is true. > >> > > > > >> > > > Could you suggest improvements? > >> > > > > >> > > > Andy > >> > > > > >> > > > >> > > >> > > > > >
