Differences

This shows you the differences between two versions of the page.

--- public:seminars_manifestations [2016/11/23 00:25]
fmichel
+++ public:seminars_manifestations [2017/03/08 10:17] (current)
fmichel
@@ Line 5: / Line 5: @@
 **SPARKS public calendar**: in [[https://calendar.google.com/calendar/embed?src=6qaafnv87osnqct6hb4ruskkcc%40group.calendar.google.com&ctz=Europe/Paris|HTML]] or in [[https://calendar.google.com/calendar/ical/6qaafnv87osnqct6hb4ruskkcc%40group.calendar.google.com/public/basic.ics|iCal]].
+====== 2017 ======
+===== Séminaires =====
+==== Marie-Christine ROUSSET: Datalog revisited for reasoning in Linked Data ====
+When: 3rd March 2017, 10h00 \\
+Where: POLYTECH, Templiers 2, room 307\\
+**Abstract**\\
+Linked Data provides access to huge, continuously growing amounts of open data and ontologies in RDF format that describe entities, links and properties on those entities. Equipping Linked Data with inference paves the way to make the Semantic Web a reality. In this presentation, I will describe a unifying framework for RDF ontologies and databases that we call deductive RDF triplestores. It consists in
+equipping RDF triple stores with Datalog inference rules. This rule language allows to capture in a uniform manner OWL constraints that are
+useful in practice, such as property transtivity or symmetry, but also domain-specific rules with practical relevance for users in many domains of interest. I will illustrate the expressivity of this framework for modeling Linked Data applications and its genericity for developing inference algorithms. In particular, we will show how it allows to model the problem of data linkage in Linked Data as a reasoning problem on possibly decentralized data. I will also explain how it makes possible to efficiently extract expressive modules from Semantic Web ontologies and databases with formal guarantees, whilst effectively controlling their succinctness. Experiments conducted on real-world datasets have demonstrated the feasibility of this approach and its usefulness in practice for data integration and information extraction.
+===== Soutenances =====
+==== PhD Thesis Defense - Franck MICHEL ====
+''Salle Euler Violet, Inria. 03/03/2017 14h''
+=== Abstract ===
+**Title: Integrating Heterogeneous Data Sources in the Web of Data**
+To a great extent, RDF-based data integration as well as the Web of Data depend on the ability to reach out legacy data locked in data silos where they are invisible to the web. In the last 15 years, various works have tackled the problem of exposing structured data in the Resource Description Framework (RDF), starting with relational databases (RDB), spreadsheets and the XML data format. Meanwhile, the overwhelming success of NoSQL databases has made the database landscape more diverse than ever. So far, though, these databases remain inaccessible to RDF-based data integration systems, and although the data they host may be of interest to a large audience, they remain invisible to the Web of Data. Hence, to harness the potential of NoSQL databases and more generally non-RDF data sources, the objective of this thesis is to enable RDF-based data integration over heterogeneous databases and, in particular, to reconcile the Semantic Web with the NoSQL family of databases.
+Firstly, we propose a generic mapping language, xR2RML, able to describe the mapping of varying types of databases into an arbitrary RDF representation. This language relies on and extends previous works on the translation of RDBs, CSV and XML into RDF. Secondly, we propose to use such an xR2RML mapping either to materialize RDF data or to dynamically evaluate SPARQL queries on the native database. To spur the development of SPARQL interfaces over legacy databases, we propose a two-step approach. The first step performs the translation of a SPARQL query into a pivot abstract query based on the xR2RML mapping of the target database to RDF. In the second step, the abstract query is translated into a concrete query, taking into account the specificities of the database query language. Great care is taken of the query optimization opportunities, both at the abstract and the concrete levels. To demonstrate the effectiveness of our approach, we have developed a prototype implementation for MongoDB, the popular NoSQL document store. We have validated the method using a real-life use case in Digital Humanities.
 ====== 2016 ======
@@ Line 50: / Line 77: @@
 ===== Soutenances =====
 ==== PhD Thesis Defense - Atheer AL-NAJDI ====