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Re: Micellaneous

From: Sebastian Samaruga <cognescent@gmail.com>
Date: Wed, 17 Sep 2014 14:54:51 -0300
Message-ID: <CAFnmbpUA3svR9GadUBF4=a7ZssPZg1g4kNz8Nku9SYh-Nm0qeA@mail.gmail.com>
To: Pat Hayes <phayes@ihmc.us>
Cc: "Thierry BIARD, EIRL AMBESAS" <thierry.ambesas@gmail.com>, "semantic-web@w3.org" <semantic-web@w3.org>, "pragmaticweb@lists.spline.inf.fu-berlin.de" <pragmaticweb@lists.spline.inf.fu-berlin.de>
Ok, I should have stated that this is intended to build an API in some
language to perform the mentioned operations.

Aggregating URIs means that if they occur multiple times in a closed world
model in which I know all the statements then I can be sure that they
represent the same thing. Another task of a given ETL tool could be perform
merging and mapping of some kind, maybe to an upper ontology to facilitate
this task.

The algorithm for types is there and it is working. Those are inferred
types and as in the previous paragraph I suppose a closed world like, for
example, and RDF dump of a relational database. This closed world
assumption can be relaxed having the possibility of merging multiple
documents in the ETL component.

Methods and contexts refer to the to be implemented API. Sorry for not be
clear enouth about that. And Resource class methods (getXXX) receive the
context as their arguments which can be one of the tree possible arguments
listed. Subclasses (Concept, Thing, Sign) may override this behavior.

Best,
Sebastian Samaruga.


On Wed, Sep 17, 2014 at 2:13 PM, Pat Hayes <phayes@ihmc.us> wrote:

>
> On Sep 17, 2014, at 9:30 AM, Sebastian Samaruga <cognescent@gmail.com>
> wrote:
>
> > Thierry, thanks really for your time answering my emails. I didn't take
> the online course. Although I've spending some of my time in some kind of
> semantic (semiotic) metamodel for what I understand as knowledge
> representation..
> >
> > I'm copying this mail to the liists.
> >
> > For what I came with, the core concepts, borrowed from semiotics, are:
> > 1. Concept
> > 2. Thing
> > 3. Sign
> >
> > First, a Sign is an occurrence of a Thing in some context. For example,
> in RDF, some URI referring something that somehow exist.
> >
> > A Thing is something that can exist and, given that notion, can appear
> in occurrences of some kind. A thing also aggregates all of its occurrences
> as they represent the Thing as a whole.
> >
> > Finally, a Concept is an abstraction of a set of Things. Things are
> instances of Concepts and, again, which Concept they are instance of is
> context dependent. A Thing could be regarded as an occurrence of a Concept.
> >
> > So, given that I begin with Things and I need a source of them I can
> begin with some RDF source without the need of any schema embedded in it.
> The URIs in the triples are Signs.
>
> OK so far, although RDF does not support contexts, so a given IRI is
> assumed to denote the same thing everywhere it occurs.
>
> > Aggregating all occurrences of the same URI I came up with the Thing
> they represent.
>
> ? How does that work? What do you mean by 'aggregating'? And how can you
> know if you have all the occurrences of a given IRI, on the entire Web?
> (You can't possibly know this.)
>
> > Then using a simple algorithm of which URIs share the same predicates I
> can infer the type of the URIs and came up with the Concepts.
>
> That is not going to work, because you would also need to know the domain
> and range properties of those predicates, and that information is not
> always given explicitly. At the very least, you will need RDFS or OWL type
> reasoning here.
>
> >
> > Now, the meta model:
> > The core concepts inherits from a Resource class. This parent class has
> the following methods:
>
> "methods"? That term is not meaningful in RDF.
>
> >
> > Resource::getSigns(Sign | Thing | Concept) : Occurrences of argument
> > Resource::getThings(Sign | Thing | Concept) : Instances of argument
> > Resource::getConcepts(Sign | Thing | Concept) : Classes / roles of
> argument.
> >
> > Example data:
> > aPerson :employment anEmployment (Signs)
> > Peter :employment SalesDptManager (Thiings)
> > Person, Employe :employment Employment, Position (Concepts)
> >
> > So, care must be taken building an ETL RDF tool that populates this
> bindings in Resource instances, provides querying facilities and support
> the construction of entities which apply rules-transformation kind of
> behavior using 'template' resources.
> >
> > Then the model should allow to build queries navigating Resource APIs
> like retrieving all the Concepts a Thing plays in a context, which Signs
> are instances of a given Thing in a given Concept context, etc.
>
> To repeat, there are no contexts in RDF.
>
> I would strongly recommend that you read more about RDF and its intended
> semantics before proceeding.
>
> Best wishes
>
> Pat Hayes
>
> >
> > Best,
> > Sebastian Samaruga..
> >
>
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Received on Wednesday, 17 September 2014 17:55:53 UTC

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