Re: SSN ontology Issue

Hi Myriam,

Take into account that they are not necessarily duplicate, since they refer
to two different restrictions: the first one establishes that the
cardinality of observedBy when applied to Observation is 1, and is of range
Sensor; the second one tells you that all possible values of observedBy when
applied to instances of Observation are of type Sensor.

Imagine that we did not have the second restriction. Then nothing would
preclude us from the possibility of adding yet another restriction saying
that, when applied to observations, observedBy has cardinality 1 with range
XX, which may be disjoint with Sensor. This is because these are qualified
restrictions.

I hope that this answer clarifies your question.

Oscar

-- 

Oscar Corcho
Ontology Engineering Group (OEG)
Departamento de Inteligencia Artificial
Facultad de Informática
Campus de Montegancedo s/n
Boadilla del Monte-28660 Madrid, España
Tel. (+34) 91 336 66 05
Fax  (+34) 91 352 48 19

De:  Myriam Leggieri <myriam.leggieri@deri.org>
Fecha:  Tue, 31 May 2011 17:06:43 +0100
Para:  <public-xg-ssn@w3.org>
CC:  Alexandre Passant <alexandre.passant@deri.org>
Asunto:  SSN ontology Issue
Nuevo envío de:  <public-xg-ssn@w3.org>
Fecha de nuevo envío:  Tue, 31 May 2011 16:11:04 +0000

    
 Hi,
 I think there's the following mistake in the SSN Ontology. Into the
ssn:Observation definition there's a restriction onProperty observedBy (row
155) which has been repeated twice and in different ways (the first time
with a cardinality restriction and the second one without it):
 
 <rdfs:subClassOf>
 
             <owl:Restriction>
 
                 <owl:onProperty
rdf:resource="http://purl.oclc.org/NET/ssnx/ssn#observedBy"
<http://purl.oclc.org/NET/ssnx/ssn#observedBy> />
 
                 <owl:onClass
rdf:resource="http://purl.oclc.org/NET/ssnx/ssn#Sensor"
<http://purl.oclc.org/NET/ssnx/ssn#Sensor> />
 
                 <owl:qualifiedCardinality
rdf:datatype="http://www.w3.org/2001/XMLSchema#nonNegativeInteger"
<http://www.w3.org/2001/XMLSchema#nonNegativeInteger>
>1</owl:qualifiedCardinality>
 
             </owl:Restriction>
 
 </rdfs:subClassOf>
 
 <rdfs:subClassOf>
 
             <owl:Restriction>
 
                 <owl:onProperty
rdf:resource="http://purl.oclc.org/NET/ssnx/ssn#observedBy"
<http://purl.oclc.org/NET/ssnx/ssn#observedBy> />
 
                 <owl:allValuesFrom
rdf:resource="http://purl.oclc.org/NET/ssnx/ssn#Sensor"
<http://purl.oclc.org/NET/ssnx/ssn#Sensor> />
 
             </owl:Restriction>
 
 </rdfs:subClassOf>
 
 Best regards,
 Myriam