Re: SDW plenary agenda item - Namespace for SOSA and SSN ontology

> > "unify:Platform rdf:type owl:Class" in the SSN ontology (FULL) is not
> necessary and should be removed as the axiom is already imported from the
> SOSA ontology (CORE). Correct?
>

True, this is superfluous.
I just updated the wiki page and deleted this axiom. Thanks.



>
> Thanks,
> Clemens
>
>
> On 22 Feb 2017, at 12:57, Maxime Lefrançois <maxime.lefrancois@emse.fr>
> wrote:
>
> Dear Clemens,
>
> > If I take a term that is in both ontologies (e.g., I can see Sensor in
> both sosa.ttl > and ssn.ttl, with different properties), where does
> http://www.w3.org/ns/unify/TermInBothOntologies take me, the SOSA or the
> SSN ontology? I assume SOSA as the "core".
>
>
> A term would be defined in at most one ontology, CORE or FULL.
>
>
> Potentially, if this ontology is CORE, this term will be further
> axiomatized (not defined), in the ontology FULL.
>
> So to answer your question, looking up URI
> http://www.w3.org/ns/unify/TermInBothOntologies would redirect you to
> CORE ontology if it is defined  in CORE.
>
>
> > So, both ontologies would define a unify:TermInBothOntologies.
>
>
> FULL imports CORE and  adds  axioms to its terms.
> FULL does not "define" the terms that were already defined in CORE.
>
>
> > If I look at the SSN ontology I would "see" a different
> unify:TermInBothOntologies than I see when looking at the SOSA ontology or
> when de-referencing the unify:TermInBothOntologies URI (which redirects to
> the SOSA ontology).
>
>
> You would see the same resource identified  by the same, URI, but with
> additional information about it (axioms)
>
>
> > If my understanding is correct, shouldn’t there be a constraint that the
> SSN ontology includes the SOSA definitions plus additional ones (at least
> for the SOSA terms that are included in SSN)?
>
>
> This is very true, we model this with the owl:imports axiom. FULL imports
> CORE, hence every axiom that is in CORE is directly "imported" in FULL.
>
>
>
> Is this approach common practice and will this be understood?
>
>
> having an ontology O2 that imports another  ontology O1 and adds axioms to
>  the terms that are defined in O1 is common practice. See for instance SKOS
> and SKOS-XL.
>
> on the other hand, what's new here is that the two ontologies share the
> same namespace. AFAIK, this technical solution has first been proposed for
> the modularized and versioned ontology developed during the ITEA2 SEAS
> project, whose core modules actually generalize the core of the SSN
> ontology:
>
> See
> Maxime Lefrançois, Jarmo Kalaoja, Takoua Ghariani, Antoine Zimmermann, The
> SEAS Knowledge Model, ITEA2 12004 Smart Energy Aware Systems Deliverable
> 2.2, Jan 2017 -
> http://www.maxime-lefrancois.info/docs/SEAS-D2_2-SEAS-Knowledge-Model.pdf
>
> Did I answer your questions ?
>
> Kind regard,
> Maxime Lefrançois
>
>
> Best regards,
> Clemens
>
>
>
> On 22 Feb 2017, at 03:39, Armin Haller <armin.haller@anu.edu.au> wrote:
>
> Krzysztof, thanks for pointing that out! That was indeed a mistake, it
> should have read sosa:Platform and ssn:System. There is no sosa:System in
> our current proposal. But tomorrow it is all about the vote on the
> mechanics of the namespace for SOSA and SSN.
>
> On 22/2/17, 11:27 am, "Krzysztof Janowicz" <janowicz@ucsb.edu> wrote:
>
>    Just to avoid confusion. Armin is talking about ssn:System, not
>    sosa:System (which does not exist). The concept that does exist in SOSA
>    is sosa:Platform.
>
>
>    On 02/21/2017 03:56 PM, Armin Haller wrote:
>
> Hi Raphaël,
>
> Thanks for your comment! In fact, the wiki is so detailed on the mechanics
> is because we *only* want to vote on the mechanics of the namespace issue
> tomorrow. The classes/properties that are shown are only exemplative. We
> have separate issues around the Platform and System class (i.e.
> https://www.w3.org/2015/spatial/wiki/Platform). In fact, there is a
> sosa:System and all current proposals under consideration in the
> Platform/System issue do retain a sosa:System class in the core. Please do
> ignore the modelling of those classes for tomorrow’s vote.
>
> Once we have come to a decision on the *mechanics* on how to deal with
> namespaces we can tackle the remaining issues with the architecture of the
> integration (see also
> https://www.w3.org/2015/spatial/wiki/Proposals_for_rewriting_SSN), i.e.
> essentially a decision on *reuse of classes/properties only in SSN* or
> *equivalence/subclass/-property relationships in SSN to SOSA classes/
> property*.
>
> Cheers,
> Armin
>
> On 22/2/17, 10:24 am, "Raphaël Troncy" <raphael.troncy@eurecom.fr> wrote:
>
>     Dear Armin, all,
>
> If you have an opinion on this, please do have a close look at the two
> options on our Wiki page that outline the implementation implications of
> each option: https://www.w3.org/2015/spatial/wiki/NamespaceIssue
>
>
>     I think that the two options are insufficiently described in order to
>     make an informed decision (sections 3.1 and 3.2). There is a lot of
> text
>     explaining the mechanics of content negotiation which is sort of
> obvious
>     for anyone who is familiar with the linked data concepts. On the
>     contrary, there is insufficient information on the bulk of the issue,
>     i.e. what (concepts and properties) is defined where, what is re-used,
>     what is being further defined with more axioms between SOSA and (new)
> SSN.
>
>     In the current option 1, one can only see the definition of a
>     sosa:Platform in the sosa namespace, while this concept is further
>     axiomatized in ssn.ttl using the concept of ssn:System. Does this mean
>     that there is no sosa:System?
>
>     I wish that the wiki page was not distracted by all the mechanics of
>     trivial content negotiation and linked data terms dereferencing, and
>     instead, focus on what is defined where precisely and exhaustively.
>     Best regards.
>
>        Raphaël
>
>     --
>     Raphaël Troncy
>     EURECOM, Campus SophiaTech
>     Data Science Department
>     450 route des Chappes, 06410 Biot, France.
>     e-mail: raphael.troncy@eurecom.fr & raphael.troncy@gmail.com
>     Tel: +33 (0)4 - 9300 8242 <04%2093%2000%2082%2042>
>     Fax: +33 (0)4 - 9000 8200 <04%2090%2000%2082%2000>
>     Web: http://www.eurecom.fr/~troncy/
>
>
>
>
>    --
>    Krzysztof Janowicz
>
>    Geography Department, University of California, Santa Barbara
>    4830 Ellison Hall, Santa Barbara, CA 93106-4060
>
>    Email: jano@geog.ucsb.edu
>    Webpage: http://geog.ucsb.edu/~jano/
>    Semantic Web Journal: http://www.semantic-web-journal.net
>
>
>
>
>
>