- From: Ghalem Ouadjed (EOWEO) <gouadjed@eoweo.com>
- Date: Fri, 18 Nov 2011 11:53:56 +0100
- To: semantic-web@w3.org
Thank you for your answers. i had to precise that i m wroking on a closed application and even if foaf doesn t contain the property i need the query works on Jena... to be less specific, i would like to know how to look for a schema based on a specific need regarding the property ? is there a way to determine that there is one or more schema which contain one or more property i envision to use. This could help to decide if i have to write a lightweight one or to use an existing one... I can realize that this kind of problematics doesn t correspond to a dogmatic vision but i know and experiment the needs of some middle size companies aiming to use semantic technologies in a pragmatic way for closed applications like internal KM solutions for instance and why not which could be enhanced and contextualised by linked datas... Thank you again for your time Cheers Ghalem Le 18/11/2011 10:33, Heiko Paulheim a écrit : > Due to the open world assumption, the value of that counter would > (probably) we wrong. > > If I have > :Peter foaf:knows :Stephen . > :Peter foaf:knows :Marc . > > and, based on that knowledge, I added > > :Peter myschema:friendnb "2"^^xsd:integer . > > this would not be a valid conclusion - there may be a lot more friends > of Peter which are not in my knowledge base (don't we all have friends > without a facebook account?), and :Stephen and :Marc might even refer > to the same person. In other words, with that approach, I would add > knowledge to my knowledge base which is potentially wrong. > > So I would rather refrain from doing that. > > Best, > Heiko. > > Am 18.11.2011 10:28, schrieb Melvin Carvalho: >> On 18 November 2011 10:20, Heiko >> Paulheim<paulheim@ke.tu-darmstadt.de> wrote: >>> Dear Ghalem, >>> >>> since such a property would be in a conflict with the open world >>> assumption >>> underlying the semantic web (you simply cannot tell "how many things >>> of type >>> X are there" in an open world), I suppose there is no serious schema >>> which >>> has such a property. >> What if you kept a separate tally to aggregate total friends as they >> are added? >> >>> Best, >>> Heiko. >>> >>> >>> >>> Am 17.11.2011 18:40, schrieb Ghalem Ouadjed (EOWEO): >>> >>> Hi everyone, >>> i would like to use a schema which is different and complementary of >>> the >>> foaf one, and which could contain a property like "number of friends". >>> >>> Does someone know an available ontology i could use pls? >>> >>> one of my query would look like : >>> >>> PREFIX rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" >>> PREFIX rdfs="http://www.w3.org/2000/01/rdf-schema#" >>> PREFIX dc="http://purl.org/dc/elements/1.1/" >>> PREFIX foaf="http://xmlns.com/foaf/0.1/" >>> PREFIX ............="_" >>> >>> SELECT ?friendnb WHERE { ?Person ...;;;;:friendnb ?friendnb } >>> ------------ >>> | friendnb | >>> ============ >>> | "\n330\n" | >>> ------------ >>> Thank you in advance for your advices and your time >>> >>> Cheers >>> Ghalem >>> >>> -- >>> Dr. Heiko Paulheim >>> Knowledge Engineering Group >>> Technische Universität Darmstadt >>> Phone: +49 6151 16 6634 >>> Fax: +49 6151 16 5482 >>> http://www.ke.tu-darmstadt.de/staff/heiko-paulheim > > >
Received on Friday, 18 November 2011 10:54:38 UTC