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Re: SPARQL & SemWeb

From: Danny Ayers <danny.ayers@gmail.com>
Date: Sun, 16 Apr 2006 13:08:05 +0200
Message-ID: <1f2ed5cd0604160408k3ae3e4fcw5f157edb73200155@mail.gmail.com>
To: "Christopher Schmidt" <crschmidt@crschmidt.net>
Cc: "Luk Vloemans" <luk.vloemans@student.uhasselt.be>, semantic-web@w3.org, www-archive@w3.org

On 4/16/06, Christopher Schmidt <crschmidt@crschmidt.net> wrote:
>
> On Fri, Apr 14, 2006 at 10:22:53AM +0200, Luk Vloemans wrote:

> > Let's presume you have a RDF dataset
> > X  latitude    123.123
> > X longitude   465.456
> > Y latitude     234.234
> > Y longitude   567.567
> > I would like to query SemWeb to get : all objects within a radius of N
> > kilometers of a specified lat/lon.
>
> > How would one get such results? Is it even possible? I would appreciate your
> > insight!

What Chris said re. using SPARQL and rectangle approximations etc.

> However, both of these solutions are based on the existence of a
> queryable crawler that will tell you either what documents contain a
> certain term (geo:Point) or allows you to execute queries against it,
> and I'm not sure if either exists.

An alternative (or augmentation) here to trying to crawl available
data and loading a global-scoped database up front might be to make
the discovery just-in-time, and leverage existing online Geo sources.
Interfacing with services like Google Maps should be possible (Chris?)
, and things are appearing like Geotagging photos in Flickr [1] and
then there's some Geo info available through various blogging systems
(and FOAF). Fairly directed queries of these could be made, with a
temporary fairly small-scale triplestore being used for data
integration. You might want to use some fairly static dataset as a
starting point - maybe something from Wikipedia or the CIA World
Factbook.

There may be some interesting crawl heuristics around - if you find
one document that's about a particular area, there's a fair chance
that some of the sites to which it links contain geographically
related info, and there may be keywords in any text that may help in
directing a search (e.g. through the Google API).

Cheers,
Danny.

[1] http://www.flickr.com/groups/geotagging/

--

http://dannyayers.com
Received on Sunday, 16 April 2006 11:08:21 GMT

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