Cool URIs for the Semantic Web

During practical RDF projects, one big challenge is always how to choose good URIs for your resources. The RDF standards say very little about this topic. There are some best practices and helpful recommendations, but they are scattered all over the web. Creating “cool URIs for the semantic web” is hard.

Richard Cyganiak, Max Völkel and myself have written an article about how to choose cool URIs, filled with practical knowledge and background information about the problem and solutions. We have collected what we have learned during projects such as Semantic MediaWiki, dbpedia, D2R Server, Gnowsis, and Nepomuk. We hope that this article is a help for you or your students to get started programming Semantic Web applications.

Read it

Abstract
The Resource Description Framework RDF allows you to describe web documents and resources from the real world—people, organisations, things—in a computer-processable way. Publishing such descriptions on the web creates the semantic web. URIs are very important as the link between RDF and the web. This article presents guidelines for their effective use. We discuss two strategies, called 303 URIs and hash URIs. We give pointers to several web sites that use these solutions, and briefly discuss why several other proposals have problems.

Notice: we have written the article late last year, but published it this year. You can republish or copy this article under the Creative Commons Attribution-NoDerivs 2.0 License.

geo markup of photos

I was on a sailing holiday at the beginning of February, ten people on a catamaran in the Carribean. Thanks to sailing, we had an Offshore Navigator on a laptop, recording the positions with a GPS mouse.

Using this GPS track and the photos taken with our two cameras, I was able to create a KML file from the journey. I used some custom PHP code I have written, a little MySQL/PHP/FlickrApi/GoogleMaps hack. It took two days to hack, which is quite nice. Included is a photo annotator to place pictures with some productivity tools (copying the position from one picture to another).

The first result is a Google Earth KML file. It shows the track of the boat and the pictures from Flickr. The other crew members don’t have flickr accounts… yet.
google earth view of the tour

Second, I wrote another script that sets the needed geo-tags on flickr based on the geocoding. See my flickr map.
flickr map of the tour

Now that I have the code, I would love to go on with these things. Is there an open source project which dedicates itself to such mashups? We could also use Chris Bizer and Richard Cyganiaks D2RQ to make a sparql-endpoint for geo positions. Who is in?

Is there an API for plazes.com? So many things to do 🙂

Semantic Desktop Workshop 4, 12th – 14th April 2007, Berlin

Announcement:

The Semantic Desktop Hands-on Workshop will be an opportunity to learn about ongoing research and development effort in the area of Semantic Desktop, Semantic Web, and Personal Knowledge Management. It will consist of a scheduled program of talks, presentations and demos, and self-organized phases of active software development in small teams, going into hands-on development on concrete projects together.


Participants are practitioners, researchers, and interested IT persons; it is encouraged to contribute by presentations or demos of your work. Deadline for registration and submissions is March 28th.

Date & Place
April 12th – 14th, 2007,
Freie Universität Berlin,
Takustr. 9,
Berlin,
Germany

This is the perfect opportunity to meet Semantic Web people, visit Berlin, learn and do Semantic Web things. Registration, participants list, more details are all on the wiki page. Feel free to add your contributions there.
* http://www.semanticdesktop.org/xwiki/bin/view/Wiki/SemDeskHandsOn2007April

Personal URI and integrating data from variuous sources

Kingsley Idehen, Uldis Bojars and John Breslin have published some ideas on how to link data from various web 2.0 sites.

Thats exactly what we wanted to implement in gnowsis 0.9.2, although we missed the great looks for it 🙂 look here!

Here are the blog posts about it

The idea is to use URLs from OpenID to identify people, a good approach.
Some things have to be thought of:

  • It should be connected with the required 303 redirects (a person is not a document, the URL must not return a web document but instead a 303 redirect).
  • Not only to aggregate the data, but also to aggregate the ideas. We need to create a personal tag cloud, like we have done in the PIMO

If you dig Java, checkout the aperture.sourceforge.net project to find code that reads flickr, can and should be extended.

Registerfly for gnowsis.org

Things happening to the world at large affect us all…. the domain registrar registerfly.com is having problems at the moment, including boulevardesque stories like two technicians locking themselves in the datacenter to bring up the site or locking out Kevin Medina who spent all the company money on personal entertainment. Movie material!

The story got Slashdotted and thankfully, Gunnar has pointed me to the post.

So, why am I concerned? Because gnowsis.org, gnogno.org and foafme.com are registered at … registerfly. I didn’t have many problems with them until now, but since the slashdotting and public outrage (mayhem, apocalyptic riders, Kevin Medina in a private orgy…) I am a bit nervous.

How I got out, at least I think so
The registrar eNom, a former partner of registerfly, sent out e-mails to all registerfly customers with a link you could click to automatigally move your domains to enom. At first, I tried this (for fun) with foafme.com. Today I did the same for the other domains. I hope that the DNS setup remains the same. If my domains go down in the next weeks, don’t worry, it will sort out for itself, I trust God helps me with this one (see below). ENom has written this e-mail after the transfer, which seems ok with me (some parts overwritten with ? by me):

Subject: Domain Push Summary Report
Date: Wed, 21 Feb 2007 04:46:01 -0800

Dear Leopold Sauermann:

Below you will find a summary of results for domains you requested be pushed to alternate accounts

DomainName Destination Result
=======================================================================
?????? ???????? Ok to push
?????? ???????? Ok to push

Thank you for selecting us as your registrar of choice

Sincerely,
eNom, Inc.

On the eNom website, you can go to “Manage Domain”, then “General Settings”, there is a “Email Auth Code to Registrant” button. Press that, I instantly got my auth code, and I will use that now to move one of the domains, as a test if all is ok.
I don’t know if this means that my domains are in safe harbour, but at least I can go on with the rest of the work for today and stop worrying about …

Here a snip by gigne from slashdot about Kevin’s great actions for personal profit.
In case anyone has no idea what this is all about, I summarised the points:

* Joint Director Kevin Medina was removed from the company for embezzlement of funds due to Registerfly’s inability to pay it’s upsream registrars.

source http://registerflies.com/docman/cat_view.html [registerflies.com]

complaints Filed in new Jersey:- Claims
1) Wiring 3x $9000 to personal accounts
2) $10000 to pay rent on apartment on a monthly basis
3) Paying large personal credit card bills
4) $6000 for liposuction
5) tens of thousands on “personal spending”

* they terminated Kevin Medina
http://registerflies.com/docman/doc_download-5.htm l [registerflies.com]

* Kevin Medina caused other untold system problems *not verified from any source, just speculation on registerflies

* Registerfly seem to be concentrating on fixing this.

Pretty confusing though.

In the bible (Galatians 5, we read it yesterday in my bible group) this would be called “sinful nature”, read the great verses 16 to 21 yourself:

So I say, live by the Spirit, and you will not gratify the desires of the sinful nature. …..
The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God.

I would conclude that I rather try to stay on the spirit side and not on the sinful nature, because that gives more joy (read verse 22-26).

Deliriously yours: Sesame 2.0-beta1

It has happened! The Sesame developers finished the first beta of Sesame 2.0. This day marks a great moment in RDF development, as we have a successor to the very popular sesame1 server. Leobard says: well done guys, gratulations, enjoy, cherish, drink beer, a good reason to do mardi gras. Here the full annoncement, as received via e-mail:

We are ecstatic to be able to announce the first beta release of Sesame
2.0! Sesame 2.0-beta1 marks the end of architectural changes to Sesame 2
and allows us to focus on adding features and fixing bugs, and you to
finally see the Sesame 2 API as it is meant to be. You can find the
latest version in the download section at http://www.openrdf.org/ .

So what’s new in Sesame 2.0-beta1 compared to previous alpha releases?

* Repository, Sail and Query APIs stable.
We have moved from alpha-stage to beta-stage, meaning that the
core APIs, the interfaces and method signatures, are now frozen
and stable. This ensures that you as a developer will be able to
upgrade to future releases without fear of breaking your
application. See the JavaDoc API documentation and the user
documentation for more details.
* Improved Context Support.
We have improved the way Sesame handles contexts, allowing
developers to freely access any combination of zero, one or more
contexts in a single repository. Use of Java 5’s vararg feature
ensure a flexible, easy-to-use API.
* Sesame 2.0 Web Client.
beta1 features the first release of a web client for Sesame
servers. This web client can be deployed as a webapp and can be
used to conviently query and modify a Sesame repository running on
a (remote or local) Sesame 2.0 server.

For a more complete and detailed overview of changes, see the ChangeLog
at http://www.openrdf.org/ .

Of course, we would not call it beta if there were not some things
missing as well. Our ToDo list includes:

* A MySQL storage backend is under development but not yet available
in this rlease.
* Custom inferencing is not yet available.
* The SPARQL query engine does not yet support ordering and a few
other language features.
* Fine-grained security on repositories is not yet available.

As remarked before, this beta release marks an important step in Sesame
2.0 development: instead of focusing our development efforts on the core
structure and architecture we can now start paying attention to
(aforementioned and other) features. You can expect regular beta
releases as we add more of the ‘good stuff’.

Of course, we owe a great debt to the many contributors and
co-developers of Sesame 2. Thank you all for your patience, and we hope
you are as pleased with the result as we are.

Deliriously yours,
the OpenRDF development team
— Aduna – Guided Exploration www.aduna-software.com Prinses Julianaplein 14-b 3817 CS Amersfoort The Netherlands

Europa Island – the place to go

Looking on arte.tv at the french elecetions, we see that one of the candidates went to La Reunion to get more supporters. La Reunion? Another overseas departement of France, like the one we visited, Martinique.

So browsing in wikipedia on these things, we find that France has a lot of overseas departments and territories (which are all on the EURO bills). And then I found the dream island – EUROPA

  • its got a cool name
  • people tried to inhabit it but died – I love the challenge
  • its part of the EU – what could seriously happen when going there (although madagascar claims it)
  • and finally, I got convinced by this sentence: The island … has a meteorological station and is visited by scientists.

I am a scientist! I can go there!

This is a moment like Johannes Grenzfurthner had it when he fell on a world map in front of the Museumsquartier and hit an antarctic island with his nose: lets find out how to get there.

Matatour 2007 – chilliger carribean Törn

IMG_3690

This entry in german, as most people involved are german speaking… non-german speakers enjoy watching the video or the pics.

Wie schon angekündigt, waren wir von 27.1.2007 bis 11.2.2007 auf einem Yacht-Törn in der Karibik. Wir sind in Martinique mit einem Katamaran gestartet, dann mit vielen Stops in den Süden und zurück. Jeden Tag Sonne, Palmen, Segeln, viel Regen und karibisches Essen.

Continue reading “Matatour 2007 – chilliger carribean Törn”

typo3 board 07 – podcast

back to work, back to the web, just sitting on my couch with Rinne, a typo 3 guy who was with the T3BOARD07 – a snowboarding week of typo3 geek and geekines.

watch their amazing video of a week of snow and party…

Colorful and entertaining report from the TYPO3 event of the year!. T3BOARD07 was held in France, Les Deux Alpes, last week in January – the 6th time! 130 participants from 10 countries in Europe. You will see snow, people, girls, football, tour de chambres and what was on the agenda for the lucky ones. And some extra gags are thrown in.


THE VIDEO

Hey, we should do the same with Semantic Desktop in Europe. The Semantic Snow 2008 – who is in?