Nofar Carmeli, Technion, Israel Institute of Technology 28 February 2020, 10:30-11:30 ENS, S16 The Complexity of Answering Unions of Conjunctive Queries We discuss the complexity of enumerating (listing) the answers to a query over a relational database. In particular, we consider three variants: arbitrary order, uniformly random order, and random…
Evgenia (Eugenia) Ternovska Associate Professor | School of Computing Science Simon Fraser University 8888 University Dr., Burnaby, B.C. V5A 1S6 13 February 2020, 10:30-11:30 ENS, S16 Logic of Information Flows: Expressing Reachability and Cardinality Properties A challenge in descriptive complexity is to identify logics with low complexity that simultaneously express…
Silviu Maniu, Université Paris-Sud 7 February 2020, 10:30-11:30 ENS, S16 An Experimental Study of the Treewidth of Real-World Data Treewidth is a parameter that measures how tree-like a data instance is, and whether it can reasonably be decomposed into a data structure resembling a tree. Many computation tasks are known…
Juan Sequeda 29 November 2019, 10:30-11:30 ENS, S16 A Brief History of Knowledge Graph’s Main Ideas Knowledge Graphs can be considered to be fulfilling an early vision in Computer Science of creating intelligent systems that integrate knowledge and data at large scale. The term “Knowledge Graph” has rapidly gained popularity…
6 December 2019, 10:30-11:30 ENS, S16 Order-invariant first-order logic over hollow trees. Order-invariant first-order logic is the extension of first-order logic in which the usage of an additional ordering relation on the structure’s universe is allowed, provided that the evaluation of sentences is independent of the choice of a particular…
8 November 2019, 10:30-11:30 ENS, S16 Weighted Linear Bandits for Non-stationary environments. We consider a stochastic linear bandit model in which the available actions correspond to arbitrary context vectors whose associated rewards follow a non-stationary linear regression model. In this setting, the unknown regression parameter is allowed to vary in…
***A modern theory of database query languages.*** * September 30, October 4, 7, 11, 14, 18 and 25, 2019. * 10:30-12:00 * Room 3052 of the Sophie Germain Building, Université Paris-Diderot (1, place Auréie Nemours, 75013 Paris). https://www.sciencesmaths-paris.fr/en/leonid-libkin-2019-1008.htm
23 August 2019, 10:30-11:30 ENS, S16 ** Yann Ramusat : Provenance-Based Routing in Probabilistic Graph Databases. Abstract: Optimizing routing queries over graphs is a rich research area with important applications, e.g., to road and transportation networks. Thanks to progress made during past decades, current-day systems are able to compute paths…
Rafael Peñaloza, University of Milano-Bicocca 12 July 2019, 10:30-11:30 ENS, S16 Lean Kernels: A Bridge Between Justifications and Provenance A justification is a minimal set of constraints (or axioms) responsible for a consequence to follow from a knowledge base. Since the time required to find justifications depends on the size…
Gaël Varoquaux, Inria Saclay 28 June 2019, 10:30-11:30 ENS, S16 Statistics on tables with non-curated entries “Dirty data” is said to be the data-scientists worst time sink. We investigate a specific data-quality challenge at the intersection of database curation and statistical learning. Data tables often contain many non-numerical entries. Knowledge…
