Links' Seminars and Public Events | ![]() ![]() |
Tue, June 25, 2019 11:30 am 5:30 pm | Happy Hours Inria Lille |
Tue, June 25, 2019 10:30 am 11:30 am | Seminar Véronique Benzaken and Évelyne Contejean Elles présenteront un outil qui prend en entrée une requête SQL et sa compilation par Postrgres sous forme de plan d'exécution, et démontre (avec Coq) que la requête initiale est équivalente au plan d'exécution. Lille-Salle B21 |
Fri, June 21, 2019 11:00 am 12:00 pm | Charles |
Fri, May 24, 2019 11:00 am 12:00 pm | Seminaire Sławek |
Fri, May 10, 2019 11:00 am 12:00 pm | Seminaire Iovka |
Fri, April 12, 2019 11:00 am 12:30 pm | Alexandre Vigny in Links Seminar |
Fri, April 5, 2019 11:00 am 12:00 pm | Semyon Grigorev in Links' seminar |
Fri, April 5, 2019 11:00 am 12:30 pm | Talk of Semyon Grigorev Title: Parsing techniques for context-free path querying Abstract: Context-free path querying (CFPQ) is a case of language constrained path querying: the way to specify constraints on paths in a graph in terms of formal languages. In CFPQ language is restricted to be a context-free. Classical parsing techniques and algorithms, such as generalized LR and LL parsing, or parser combinators, can be used for CFPQ. Results of adaptation of different parsing techniques for CFPQ will be presented. B31 |
Fri, March 22, 2019 10:00 am 11:30 am | Seminar LINKS by Aurelien Lemay "Tutorial: Grammatical Inference" |
Fri, March 8, 2019 11:00 am 12:00 pm | Seminar Momar Title: Regular Matching and Inclusion on Compressed Tree Patterns with Context Variables
Abstract: We study the complexity of regular matching and inclusion for compressed tree patterns extended by context variables. The addition of context variables to tree patterns permits us to properly capture compressed string patterns but also compressed patterns for unranked trees with tree and hedge variables. Regular inclusion for the latter is relevant to certain query answering on Xml streams with references. |
Fri, February 15, 2019 11:00 am 12:00 pm | Seminar [Florent] |
Wed, February 13, 2019 1:30 pm 2:30 pm | 30mn de science : Florent Capelli on Knowledge Compilation Inria salle Plénière (Bâtiment A) |
Fri, February 1, 2019 11:00 am 12:30 pm | Bruno Guillon in Links' seminar Title: Finding paths in large graphs Abstract: When dealing with large graphs, classical algorithms for finding paths such as Dijkstra's Algorithm are unsuitable, because they require to perform too many disk accesses. To avoid this while keeping a data structure of size quasi-linear in the size of the graph, we propose to guide the path search with a distance oracle, obtained from a topological embedding of the graph. I will present fresh experimental research on this topic, in which we obtain graph embeddings using learning algorithms from natural language processing. On some graphs, such as the graph of publications from DBLP, our topologically-guided path search allows us to visit a small portion of the graph only, in average. This is joint work with Charles Paperman. B21 Room |
Fri, November 23, 2018 11:00 am 12:30 pm | Filip Mazowiecki in Links' seminar Title: Containment for Probabilistic automata. Abstract: This is an ICALP 2018 paper. We analyze when the model of probabilistic automata has decidable properties, when restricting the ambiguity. The notion of ambiguity is usually used in weighted automata or transducers, but we follow a recent paper by Fijalkow, Riveros and Worrell, which introduced this approach. We do not solve everything but our decidability results rely unexpectedly on Schanuel's conjecture and we provide some geometric intuition behind the hardness of the problem. |
Fri, November 16, 2018 11:00 am 12:30 pm | Aurelien Lemay's Habilitation defense IRCICA |
Thu, November 15, 2018 4:30 pm 5:30 pm | Andreas Maletti in Aurélien Lemay's prehabilitation seminar Lille-Salle B21 |
Thu, November 15, 2018 3:30 pm 4:30 pm | Henning Fernau in Aurélien Lemay's prehabilitation seminar: Lille-Salle B21 |
Fri, November 9, 2018 11:00 am 12:30 pm | Talk of Bruno Guillon Abstract: The time complexity of 1-limited automata is investigated from a descriptional complexity view point. Though the model recognizes regular languages only, it may use quadratic time in the input length. We show that, with a polynomial increase in size and preserving determinism, each 1-limited automaton can be transformed into a linear-time equivalent one. We also obtain polynomial transformations into related models, including weight-reducing Hennie machines (i.e., one-tape Turing machines syntactically forced to operate in linear-time), and we show exponential gaps for converse transformations in the deterministic case. |
Fri, October 26, 2018 11:00 am 12:30 pm | Momar Sakho in Links seminar "Lieu : Lille, Salle : A12" |
Thu, October 18, 2018 4:00 pm 5:00 pm | Talk of Mikael Monet Title: Combined Complexity of Probabilistic Query Evaluation Abstract: Query evaluation over probabilistic databases (probabilistic query evaluation, or PQE) is known to be intractable in many cases, even in data complexity, i.e., when the query is fixed. Although some restrictions of the queries and instances have been proposed to lower the complexity, these known tractable cases usually do not apply to combined complexity, i.e., when the query is not fixed. This talk gives an overview of my PhD research, which investigates which queries and instances ensure the tractability of PQE in combined complexity. I will first present our work on PQE of conjunctive queries on binary signatures, which can be rephrased as a probabilistic graph homomorphism problem. We restrict the query and instance graphs to be trees and show the impact on the combined complexity of diverse features such as edge labels, branching, or connectedness. This is joint work with Antoine Amarilli and Pierre Senellart and was presented at PODS'2017. Second, we will explore the combined complexity of evaluating queries on treelike databases, i.e., databases whose treewidth is bounded by a constant. We introduce a class of queries (named 'CFG-Datalog') which generalizes many known query languages that are tractable in this context. Specifically, we show that the (non-probabilistic) evaluation of CFG-Datalog on treelike databases can be solved with complexity linear in the product of the instance size and of the query size. In the process, we introduce a new representation of the provenance of a query on a database, based on cyclic Boolean circuits. This is joint work with Antoine Amarilli, Pierre Bourhis, and Pierre Senellart, and was presented at ICDT'2017. Last, we will move to the field of knowledge compilation and present our work that connects various notions of width for Boolean circuits. We show that circuits of bounded treewidth can be efficiently compiled into structured deterministic decomposable normal forms (d-SDNNFs), which in particular allows efficient probability computation. We show the implications of this result for PQE of CFG-Datalog on treelike databases. We also prove general lower bounds on knowledge compilation formalisms, which imply lower bounds for provenance computation. This is joint work with Antoine Amarilli and Pierre Senellart and was presented at ICDT'2018. "Lieu : Lille, Salle : B21" |
Fri, September 28, 2018 10:15 am 11:45 am | José Lozano Links seminar |
Fri, September 21, 2018 10:30 am 12:00 pm | Fabian Reiter in Links' Seminar: Descriptive distributed complexity This talk connects two classical areas of theoretical computer science: descriptive complexity and distributed computing. The former is a branch of computational complexity theory that characterizes complexity classes in terms of equivalent logical formalisms. The latter studies algorithms that run in networks of interconnected processors. Although an active field of research since the late 1970s, distributed computing is still lacking the analogue of a complexity theory. One reason for this may be the large number of distinct models of distributed computation, which make it rather difficult to develop a unified formal framework. In my talk, I will outline how the descriptive approach, i.e., connections to logic, could be helpful in this regard. Salle B21 |
Fri, September 7, 2018 11:00 am 12:30 pm | Rustam Azimov in Links Seminar: "Context-Free Path Querying by Matrix Multiplication" |