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Re: How can I express containment/composition?

From: Frans Knibbe | Geodan <frans.knibbe@geodan.nl>
Date: Thu, 21 Feb 2013 16:19:24 +0100
Message-ID: <51263AFC.4010508@geodan.nl>
To: Matteo Casu <mattecasu@gmail.com>
CC: public-lod@w3.org
On 21-2-2013 15:28, Matteo Casu wrote:
> The "contains" in GeoSPARQL holds between geometries, not geographic entities, so I don't think it would fit your needs.
>
> You can go with GeoNames. The following query should give you the result on a triple store (try on the FactForge endpoint or on your data once you have it):
>
> PREFIX gn:<http://www.geonames.org/ontology#>
>
> SELECT ?country (SUM(xsd:integer(?pop)) as ?tot)
> WHERE {
> ?province gn:featureCode gn:A.ADM1;
>   gn:parentCountry ?country;
>   gn:population ?pop
> }
> GROUP BY ?country
> ORDER BY DESC(?tot)
> LIMIT 1
Isn't the machine being helped in this example, by specifying that 
provinces can be grouped into countries? Couldn't the machine find it 
out for himself, making use of the knowledge that provinces are part of 
countries and therefore their integer properties may be summed?

Or, in other words (sorry for not being able to express myself more 
formally):

/Human:/ "Machine, which country has the highest number of inhabitants?"
/Machine:/ "Oh, that's easy. Let me see... There, I found a list of 
countries.
Now I will just order those countries by the number of inhabitants.... 
Darn! The number of inhabitants is not known for countries. Let me look 
further...
Hey, I see that a country is composed of provinces. And a province does 
know its number of inhabitants. Now if I can find all provinces for each 
country, I can sum the number of inhabitants and then I will have the 
total for each country.
Done!"


>
>
> Il giorno 21/feb/2013, alle ore 15:10, Frans Knibbe | Geodan <frans.knibbe@geodan.nl> ha scritto:
>
>> Barry and Matteo, thank you for pointing me to the GeoNames Ontology. Geographical containment can also be found in GeoSPARQL (http://schemas.opengis.net/geosparql/1.0/geosparql_vocab_all.rdf): sfContains.
>>
>> I had the feeling that what I primarily needed was the logical concept of containment/composition, because that would allow reasoning on the part of the data consumer. But I guess it would be best to specify both logical AND geographical containment. As far as I can tell, the geographical containment in GeoSPARQL and GeoNames does not imply logical containment. But perhaps I am overestimating the power of dcterms:hasPart?
>>
>> I was thinking about an example. Let's say the following is known:
>>
>> 1) A country consists of provinces
>> 2) For each country, the complete set of provinces is available
>> 3) For each province the number of inhabitants is available
>>
>> Could a machine answer the question "Which country has the highest number of inhabitants?" without help from a human?
>>
>> Regards,
>> Frans
>>
>>
>>
>> On 21-2-2013 14:10, Matteo Casu wrote:
>>> You could also check the GeoNames ontology, which considers administrative subdivisions: http://www.geonames.org/ontology/documentation.html
>>> E.G.: in the USA, level 1 administrative subdivisions are States. In Italy, they are Regions.
>>>
>>> It is a minor change of perspective with respect to yours.
>>>
>>>
>>> Il giorno 21/feb/2013, alle ore 14:01, Frans Knibbe | Geodan <frans.knibbe@geodan.nl> ha scritto:
>>>
>>>> Thank you Martynas, that seems to be just what I was looking for!
>>>>
>>>> Frans
>>>>
>>>> On 21-2-2013 13:54, Martynas Jusevičius wrote:
>>>>> Hey Frans,
>>>>>
>>>>> Dublin Core Terms has some general properties for this:
>>>>> dct:hasPart http://dublincore.org/documents/dcmi-terms/#terms-hasPart
>>>>> dct:isPartOf http://dublincore.org/documents/dcmi-terms/#terms-isPartOf
>>>>>
>>>>> Martynas
>>>>> graphity.org
>>>>>
>>>>> On Thu, Feb 21, 2013 at 2:47 PM, Frans Knibbe | Geodan
>>>>> <frans.knibbe@geodan.nl> wrote:
>>>>>> Hello,
>>>>>>
>>>>>> I would like to express a composition relationship. Something like:
>>>>>> A Country consist of Provinces
>>>>>> A Province consists of Municipalities
>>>>>>
>>>>>> I thought this should be straightforward because this is a common and
>>>>>> logical kind of relationship, but I could not find a vocabulary which allows
>>>>>> be to make this kind of statement. Perhaps I am bad at searching, or maybe I
>>>>>> did not use the right words.
>>>>>>
>>>>>> I did find this document:
>>>>>> http://www.w3.org/2001/sw/BestPractices/OEP/SimplePartWhole/ ("Simple
>>>>>> part-whole relations in OWL Ontologies"). It explains that OWL has no direct
>>>>>> support for this kind of relationship and it goes on to give examples on how
>>>>>> one can create ontologies that do support the relationship in one way or the
>>>>>> other.
>>>>>>
>>>>>> Is there a ready to use ontology/vocabulary out there that can help me
>>>>>> express containment/composition?
>>>>>>
>>>>>> Thanks in advance,
>>>>>> Frans
>>>>>>
>>>>>>
>>>>
>>
>>
Received on Thursday, 21 February 2013 15:20:05 UTC

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