Title : On the Impact of sameAs on Schema Matching

Presenter Joe Raad
Abstract In a large and decentralised knowledge representation system such as the Web of Data, it is common for data sets to overlap. In the absence of a central naming authority, semantic heterogeneity is inevitable as such overlapping contents are described using different schemas. To overcome this problem, a number of solutions have automated the integration of these data sets by matching their schemas. In this work, we focus on a specific category of these solutions that relies on the concepts' extension for matching the schemas (i.e., instance-based methods). Rather than introducing a new approach for the task of schema matching, this work studies the impact of exploiting the semantics of owl:sameAs in such instance-based methods. For this empirical analysis, we investigate more than 900K concepts extracted from the Web, and make use of over 35B implicit identity assertions to study their impact. The experiments show that despite the growing doubts over their quality, exploiting owl:sameAs assertions extracted from the Web can improve instance-based schema matching techniques.

Title : Logic Programming and modern Prolog

Presenter Jan Wielemaker
Abstract Once upon a time AI was (mostly) logic with a little statistics, the latter as, e.g., probabilistic logic, bayesian networks and neural networks. Logics provide an explainable way to describe the world around us and reason about it. But, the world is largely not following the ridgit rules of logic. With almost unlimited amounts of data available and huge compute resources it became possible to build _statistical_ models that can perform tasks ranging from image recognition to POS tagging and dependency parsing for natural languages to playing games. These results are truly impressive. Still, it is widely recognised that statistical methods have their limitations that are hard to overcome. Notably, these methods require huge amounts of data and generally cannot explain their conclusion. It is also common for such models to pick up signals from unintended, unwanted or unethical biases. At least in theory, statistical models can profit from rule based reasoning in reducing their need for data, avoid conclusions that simply can not be true or explain their conclusions. I have been working in Logic Programming most of my carreer as the lead developer of SWI-Prolog. Notably during the last year SWI-Prolog has greatly improved in supporting truly declarative logic based reasoning. During this WAI talk I want to outline the Logic Programming landscape and the position SWI-Prolog takes in this landscape. My aim is to seek opportunities for closer cooperation around these topics. Link to slide: https://docs.google.com/presentation/d/17WZ9yZ-eBSMj-LZ8ClO1WHmi8TpqY40iPLWcOLu2TQI/edit?usp=sharing

Title :

Presenter This is a Zoom Meeting
Abstract NEW Zoom meeting room URL: https://vu-live.zoom.us/my/joeraad?pwd=Y2FvRWNpRFJsb1ppSHVhMEU5OUV0QT09 or Meeting ID: 995 4852 3116 Password: 847806