DL-Learner

DL-Learner

Depiction of DL-Learner

The DL-Learner software learns concepts in Description Logics (DLs) from examples. Equivalently, it can be used to learn classes in OWL ontologies from selected objects. It extends Inductive Logic Programming to Descriptions Logics and the Semantic Web. The goal of DL-Learner is to provide a DL/OWL based machine learning tool to solve supervised learning tasks and support knowledge engineers in constructing knowledge and learning about the data they created.

Purposes of Class Expression Learning:

  1. Learn Definitions for Classes: Based on existing instances of an OWL class, DL-Learner can make suggestions for class definitions to be included as an owl:equivalentClass or rdfs:subClassOf Axiom. As the algorithm is biased towards short and human readable definitions, a knowledge engineer can be supported when editing the TBox of an ontology (see Protege Plugin).
  2. Find similar instances: DL-Learner's suggested class expressions can be used to find similar instances via retrieval (Concept definitions as search). Scalable methods allow the generation of recommendations on the fly, e.g. in a web scenario (see DBpedia Navigator - in experimental stage).
  3. Classify instances: The learned class descriptions can be used in a typical classification scenario, i.e. to decide for unknown instances whether they belong to a certain class. Common ILP benchmarks have been tested with DL-Learner. On the Carcinogenesis page, DL-Learner competes with other state-of-the-art ILP algorithms.


Testimonials

Dr. Mateja Verlič (Zemanta d.o.o., R&D)

We read a lot about people doing important things, however this time we – LOD2 partners – are the ones changing the history of Web by revolutionizing information use and reuse, contributing to semantic data standards and pushing the limits of almost every WWW-related aspect (sc… read

Dr. Jens Lehmann (Universität Leipzig, Research Group Leader)

The size and number of Semantic Web knowledge bases published as Linked Open Data has been growing tremendously over the past years. The LOD2 project will be a key factor for sustaining this momentum. More importantly, the quality of knowledge bases and the scalability of methods accessing… read

Jindřich Mynarz (University of Economics, Czech Republic)

Apart from being legally open, linked open data is an open technology. Due to its non-exclusive, non-proprietary, well-formalized, and standards-based nature, linked open data supports a wide spectrum of uses. It does not exclude any application from using it and thus it is open to be mixe… read

Dr. Mladen Stanojevic (Institute Mihajlo Pupin, Serbia)

The richness of any semantic model and the usability of represented data is dependent on the links between them. LOD2 is an important step in this direction that will enable an efficient exploration and processing of vast quantity of open data on the Web.

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Mun Yong Yi (Korea Advanced Institute of Science and Technology (KAIST))

Data becomes more meaningful and powerful as they are linked and integrated. As I learn more about what LOD can do, I am convinced that it will not only change the future of the Internet but also the quality of human life. I am glad that I am participating in this project, which will defin… read

Orri Erling (OpenLink Software, Virtuoso Program Manager)

Value from information increasingly depends on integration. RDF is a great model for this. LOD2 will make RDF a cost competitive alternative in the database space, without compromising ad hoc flexibility and expressive power. read

Vojtech Svatek (University of Economics, Czech Republic)

As researcher in ontological engineering, I am excited to see LOD2 provide tools that make the generation of semantically structured data easy and thus widespread. I believe that ontological research is deemed to build upon the world views already expressed by means of simpl… read

Andreas Blumauer (Semantic Web Company, CEO)

15 years ago we all were excited when we published HTML for the first time and it didn't take a long time until all of us were "on the internet". Now we are starting to publish data on the web. Based on semantic web technologies professional data management will be possible in distributed … read

Kingsley Idehen (OpenLink Software, CEO)

Three years ago, OpenLink Software enthusiastically contributed the prowess of Virtuoso to the grassroots effort that lead to DBpedia and the Linked Open Data cloud that coalesced around it. Today, we are both honored and enthusiastic about Virtuoso's critical infrastructure role in this n… read

Bastiaan Deblieck (TenForce, Partner and Business Development Manager)

An internet of data opens up tremendous opportunities for our corporate and government customers. We intend to be on the forefront of this evolution. read

Christian Dirschl (Wolters Kluwer, Content Architect)

Linked (Open) Data will change the existing publishing paradigms! Creating high quality content for professional usage will remain an important factor in future publishing, but additional access points and new usage environments will equally define its success. read

Dr. Giovanni Tummarello (National University of Ireland, Galway, Research Unit Leader)

Semantic Markups on the Web could drive information reuse to enable scenarios and applications which we can now only dream of. The idea is extraordinarely compelling, but we know now it won't simply realize itself. The LOD2 project is now a great opportunity for inspired and coordinated re… read

Gregory Grefenstette (Exalead, Chief Science Officer)

Enterpise search is all about providing correct, complete, and appropriate information to the employee and decision maker. LOD2 promises to not only allow internal company information to be linked up to the growing amount of Open Data on the web, but to also provide the mechanisms for val… read

Hugh Williams (OpenLink Software)

It is exciting to see the LOD2 project finally kick off in its quest to take the Linked Open Data cloud to the next level of scalability, performance and integration for the exploitation of the Web as a viable platform for enterprise level data and information integration. read

Martin Kaltenböck (Semantic Web Company, CFO)

Linked (Open) Data technologies offer a new way of data integration for the enterprise! Smooth interoperability between internal data sets can reduce costs as well as the enrichment of these data sets by external data can support new market intelligence paradigms for a better decision making. read

Dr. Peter Boncz (Centrum Wiskunde & Informatica)

The publishing of ever more datasets by e.g. governments adds value for many key applications including business intelligence, which will drive the Linked Open Data (LOD) paradigm going forward. In the LOD2 project, CWI is working to increase the scalability and performance of querying int… read

Dr. Sören Auer (Universität Leipzig, LOD2 coordinator)

The Linked Data paradigm is a simple and efficient way for integration of heterogeneous information on the Web. Ultimately, we will, for example, be able to search for a new appartment and a close-by available spot in child care in one go. read

Tassilo Pellegrini (Semantic Web Company, R&D)

Semantic interoperability changes the technological and economic nature of metadata opening up exciting opportunities for value creation in various comercial and non-commercial areas. Linked Data is the blueprint for this new ecosystem and it will change the way we think about and use the web today. read

Wouter Dewanckel (TenForce, WP Project Leader)

It is an honor to take part in this challenging integration project to create solutions that can generate business value out of emerging technologies. read

News

LOD2 Webinar Series: LIMES – Discovery of Links across Knowledge Bases

Mar 26, 2012 3:03:48 PM | Nadine Jaenicke

The 1st version of the LOD2 Stack has been published in September 2011 in the form of an LOD2 Stack demo and the downloadable LOD2 Stack virtual machine image – additional details and the instructions on installing the LOD2 Stack from scratch are available in the How-To-Start document. Born from the wish to make linking ...

LOD2 Plenary Meeting: WebID and Authorization SIG

Mar 21, 2012 1:49:34 PM | Sebastian Tramp

Today morning, we started the main LOD2 plenary meeting in Vienna. The first half day session the WebID special interest group discussed about WebID based single sign for the LDO2 stack and authorization. The challenge here is to provide a interoperable authorization layer which describe user, groups / roles and access to different parts of the stack as well as the managed knowledge bases. We agreed on the following short and long-time goals and activities: WebID registration service and stack ...

I-Semantics deadlines approaching (research/application papers and Linked Data Cup)

Mar 18, 2012 3:41:00 PM | Sebastian Hellmann

Several deadlines regarding the I-Semantics 2012 are approaching and we would like to give a gentle reminder to all who are thinking about a submission that now would be a good time to start writing The deadline for research and application papers (8 pages for full papers) is April 13th, 2012. Note that the abstract ...