Demo and poster at ESWC2012
There will be a poster and a demo presented at the 9th Extended Semantic Web Conference (ESWC2012) related to Linked Science and to the LODUM project:
- Tomi Kauppinen, Giovana Mira de Espindola and Benedikt Graeler. Sharing and Analyzing Remote Sensing Observation Data for Linked Science. In poster proceedings of the 9th Extended Semantic Web Conference 2012 (ESWC2012), Heraklion, Crete, Greece, May, 2012. (to appear) [BibTeX]
- This poster will present the Linked Brazilian Amazon Rainforest project.
- Carsten Keßler and Tomi Kauppinen. Linked Open Data University of Münster – Infrastructure and Applications. In Demos of the 9th Extended Semantic Web Conference (ESWC2012), Heraklion, Greece, May, 2012. (to appear). [BibTeX]
- We will demonstrate the LODUM project through two applications. One of them, the university productivity map, is already online: read more here.
Books, books, books
The University Library here in Münster has released their entire collection of bibliographic data as Open Data under a Creative Commons Zero license. Here’s a translation of the press release:
The University Library Münster (ULB) has released their catalog data as Open Data. The approximately 3.4 million records include most of the scientific literature in the library system of the University of Münster, including links to electronic full texts available there. The data are published under a Creative Commons Zero license. This results in new opportunities to query and link the catalog data and build new applications, search, and analysis tools on the basis of these data without any restrictions.
With the release of catalogue data, the ULB Münster catalog strongly supports open access to scientific information. Under the initiative LODUM (Linked Open Data University of Munster), the university is the first university in Germany to explore and use this technology. “For us, the publication of the catalog data, therefore, only the first step,” said Dr. Beatrice Troeger, director of the ULB. The library plans to expand its offerings in this area and continually improve.
The ULB has been active in the Open Access initiative for many years and is now starting to adopt the concept of Linked Data. But whereas in “open access” to the published scientific information itself goes, turns at the library for information about data sharing information. “The so-called metadata have always been the core business of libraries,” said Jörg Lorenz, Head of the Department for Digital Services. Without such data it is simply impossible to get through the ever-increasing flood of information passed to relevant scientific publications.
We have now converted these data to RDF and provide them through our store.
LODUM JSONP Proxy
Heads up: If you’re not into Web development, this post is going to bore the hell out of you.
While it is quite straightforward these days to load data dynamically via AJAX, everyone who has tried to augment their website with Linked Data via JavaScript has probably hit the wall of the same origin policy. While a script can be loaded from any arbitrary server, this policy allows the script to communicate exclusively with the same port on the same host through the same protocol. So you’re even lost if you want to load data from your triple store hosted on the same machine, but on port 8080, for example.
While the policy is there for very good (security) reasons, it can be quite an annoyance when you are trying to develop applications that pull in data from various sources in the Linked Data Cloud. JSON with padding, better known as JSONP, has been introduced as a creative workaround for this problem. It basically packs the results of a GET request as a JavaScript function; the result becomes a script of its own (the callback function), and these can be loaded from anywhere (see above). The only problem with this approach is that the server needs to support JSONP, as the results need to be packed into a JS function. In other words, if the SPARQL endpoint you are loading data from does not support JSONP, you are still lost and have to come up with a workaround such as a local proxy script.
And this is pretty much what our proxy service at http://jsonp.lodum.de does. Fire any GET requests with the following three parameters at it, and it will return the SPARQL results wrapped as JSONP:
- endpoint: The URL of the SPARQL endpoint you want to query.
- query: Your SPARQL query.
- callback: The name for the callback function you are expecting.
If you are using jQuery, you don’t even need the callback function. jQuery takes care of that part for you; Here’s a quick example:
var endpoint = “http://data.uni-muenster.de/sparql”;
var queryUrl = “http://jsonp.lodum.de/?endpoint=” + endpoint;
$.ajax({
dataType: “jsonp”,
data: {query: “SELECT * WHERE { ?a ?b ?c . } LIMIT 10”},
url: queryUrl,
success: function(data) {
// do something with the results
}
});
jQuery takes care of assigning the callback function a name and you’re ready to use the SPARQL results in JSON notation. No need to say that this also works with other endpoints.
If you don’t want to rely on our server being up, the script is also available for download, so that you can set up your own proxy.
We added a FullTextIndex (Owlim/Lucene) to the Lodum store containing all literal values. The index is named “lodumLiteralIndex” and can be queried combining SPARQL and the Lucene sytanx (Sparql Example).
On top we built a small GUI with JQuery, making the search capabilities accessible to the wider public. Even though, the index contains blank notes es well (e.g. authorlists), we still working on a smart way to integrate those into the GUI.
The RDFpad got an update as well and is now working with both Etherpad versions ( Etherpad and EtherpadLite). In addition, we built a small on-the-fly SPARQL-Tool (SPARQLfly) in order to query small, remote RDF Triples using the FROM clause (e.g. written in Etherpad or static files). The RDFpad provides automatically a link to SPARQLfly, which will then read and prepare the query form containing all namespaces.
Nice overview of how Linked Open Data works and why it’s useful from the Europeana folks.
spatial.linkedscience.org 2.0
It just occurred to me that we have not even mentioned the new version of spatial.linkedscience.org here yet. Completely new UI, and tons of new data.
We are co-organizing this workshop at GIScience 2012 on September 18th, 2012 in Columbus, Ohio. Have a look at the call for papers, we will also have a data competition.
Piling up Publications
One of the main goals of LODUM is to open up the university’s data silos, integrate the data, and make it easy to build applications on top of the data collection. This productivity map for Google Earth is an example of such an application. It renders the university buildings in 3D – the building height indicates the number of publications written by researchers working in the respective building.
The absolute number of papers is normalized by the number of researchers working in the given building for a more balanced impression. The buildings are split in two parts: the lower part indicates the number of journal papers, whereas the upper part represents all other publications.
Clicking either of these two parts opens a pop-up with the actual numbers. The distribution of publications between the different institutions in a building is visualized as a pie chart (generated by the Google Chart Tools). The pop-ups also include links to the SPARQL queries to pull the data for the given building out of our store, so that interested developers can learn how we built this map.
The KML file is also available for download.
Semantic Web in Libraries / #SWIB11
I attended the Semantic Web in Bibliotheken (i.e., … in libraries) meeting in Hamburg this week and presented our work on behalf of the team. Besides the presentation, the organizers (HBZ and ZBW) invited me to participate in the panel discussion at the end of the conference, and I would like to stress again what I said there: I think the libraries are really on top of their game when it comes to Linked Open Data. Having looked at a number of other fields in the context of LODUM, I must say that very few disciplines embrace the idea of LOD in the way the libraries do.
I was very impressed by the quality of the meeting and the presentations and made some useful new contacts (and finally met some people I only knew by email). Feedback for LODUM was also very positive, which came in both in talks over coffee and via Twitter:
It was quite a Twitter-friendly crowd in general, check the #SWIB11 hashtag on Twitter for a really impressive number of tweets from the meeting. I’d like to mention one last tweet:
I mention this one because Chris Gutteridge from Southampton came up to me and said:
I love what you’re doing, but I hate your HTML pages.
And that’s for a good reason. I think we really can (and need to) do a lot better here, and that is indeed something I would like to work on in the coming weeks. I think we’ll give Chris’ Graphite framework a shot for this task.
For the sake of completeness, my slides from SWIB11:
- Carsten
During the last few days and weeks we (Krzysztof Janowicz, Carsten Keßler, Alexander Savelyev and Tomi Kauppinen) created a Linked Data set about the people, papers and proceedings of the COSIT (Conference on Spatial Information Theory) series.
The result is now opened and can be…
