Team Edelweiss

Overall Objectives
Scientific Foundations
Application Domains
New Results
Contracts and Grants with Industry
Other Grants and Activities

Section: New Results

Graph Based Knowledge Representation

KGRAM: Knowledge Graph Abstract Machine

Participants : Olivier Corby, Catherine Faron-Zucker, Fabien Gandon.

A generic SPARQL interpreter was designed and developed as well as an Abstract Graph API. It is a generalization of SPARQL for labeled graphs, not only RDF but also Conceptual Graphs [22] , [23] , [19] .

This year we leverage KGRAM with SPARQL 1.1 statements such as: select expression, subquery, property path, minus, exist, aggregate, group by, having.

We also designed an extension that enables the mashup of data coming from several graph servers. This generic extension is used in the ISICIL ANR project.

We performed a port on Jena Semantic Web platform and on a fresh Graph structure to validate KGRAM architecture.

We also have designed several extensions that enable to enumerate edges from property paths, perform XPath queries and write pragmas to tune query execution. A generic Event Listener has been added to KGRAM that enables to write debuggers.

Graphic User Interface

Participants : Jérôme Maraninchi, Fabien Gandon, Olivier Corby.

A new version of Corese Graphic User Interface have been released with graph visualisation for construct & describe SPARQL queries [37] . The GUI also manages a SPARQL query debugger.

Graph Visualization

Participants : Erwan Demairy, Fabien Gandon, Olivier Corby.

A development activity (ADT) with support from INRIA started the 1st of October 2010 for two years, on Semantic Graph Visualization. The action focus is on coupling Corese and Gephi Open Graph Visualization Platform to provide a framework to query and visualize RDF data taking into account their schemas.

Distributed Query Processing

Participants : Adrien Basse, Fabien Gandon.

We are interested in designing an architecture to support the distribution of a SPARQL query on a small and fixed number of RDF repositories. To do so, the key stage is to characterize the content of the base of each server in order to be able to predict if a server could contribute or not to the answer of a query. Then, we propose an algorithm to extract a compact representation of the content of an RDF store. We improve the canonical representation of RDF graphs based on DFS code proposed in the litterature by providing a join operator to reduce the number of generated redundant patterns [18] .

Contextual Semantic Annotations

Participants : Noureddine Mokhtari, Olivier Corby.

This PhD thesis [15] falls within the framework of the former European project SevenPro (Semantic Virtual Engineering Environment for Product Design) whose aim is to improve the engineering process of production in manufacturing companies, through acquisition, formalization and exploitation of knowledge. We propose a methodological approach and software for generating contextual semantic annotations from text. Our approach is based on ontologies and Semantic Web technologies.

In the first part, we propose a model of "context" for text. This modeling can be seen as a projection of various aspects of "context" covered by the definitions in literature. We also propose a model of contextual semantic annotations, with the definition of different types of contextual relationships that may exist in the text. Then, we propose a generic methodology for the generation of contextual semantic annotations based on domain ontology that operates at best with the knowledge contained in texts.

The novelty in the methodology is that it uses automatic language processing techniques and grammar extraction (automatically generated), domain relations, concepts and values of property in order to produce semantic annotations associated with contextual relations. In addition, we take into account the context of occurrence of semantic annotations for their generation. A system that supports this methodology has been implemented and evaluated.

Collaborative Management of Interlingual Knowledge

Participants : Maxime Lefrançois, Fabien Gandon.

This new PhD thesis, directed by Fabien Gandon and Christian Boitet (from CLIPS-IMAG at Grenoble), is focused on filling the gap between Semantic Web technologies and the Universal Networking Language (UNL), an artificial interlingua designed for humans and computers. This may enable the design of Knowledge bases management workflows that would involve different human actors interacting in their natural language. The main goal of the thesis is to study and assist collaborative management and organization of interlingual knowledge. We plan to design and experiment a prototype to validate our work.

As a first step we are working on a formalization of some aspects of an eXtended UNL specification using recommendations of the World Wide Web Consortium. We will then propose to enable translation between UNL and SPARQL so that : a) the speech act of an input sentence can be translated to an action that can be performed on one or more knowledge bases ; b) SPARQL results could be translated to UNL, and then back to natural language.


Logo Inria