{"id":290,"date":"2023-06-15T16:49:20","date_gmt":"2023-06-15T14:49:20","guid":{"rendered":"https:\/\/leria.univ-angers.fr\/?page_id=290"},"modified":"2024-05-14T09:18:25","modified_gmt":"2024-05-14T07:18:25","slug":"seminars","status":"publish","type":"page","link":"https:\/\/leria.univ-angers.fr\/?page_id=290","title":{"rendered":"Seminars"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">14\/05\/2024 &#8211; Yi ZHOU : Recent advances in algorithms for k-plex problems<\/h2>\n\n\n\n<p>In the field of graph mining, the k-plex is a well-known extension of the basic clique model. A k-plex is nearly a clique except that each vertex is allowed to be not adjacent to at most k vertices, with k being a positive integer. When k=1, a k-plex is equivalent to a clique. Fundamental problems related to the k-plex include how to enumerate all maximal k-plexes and how to find the maximum k-plexes in a given graph. In this talk, I will present some of our recent results on these problems from the perspective of algorithm engineering. I will also introduce how techniques in the design of exact and parameterized algorithms assist in the analysis of practical k-plex algorithms.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">24-26\/01\/2024 &#8211; Seed workshop<\/h2>\n\n\n\n<figure class=\"wp-block-embed is-type-rich is-provider-twitter wp-block-embed-twitter\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"twitter-tweet\" data-width=\"550\" data-dnt=\"true\"><p lang=\"fr\" dir=\"ltr\">Lancement du consortium <a href=\"https:\/\/twitter.com\/hashtag\/chain2sustain?src=hash&amp;ref_src=twsrc%5Etfw\">#chain2sustain<\/a> de <a href=\"https:\/\/twitter.com\/EUGREENalliance?ref_src=twsrc%5Etfw\">@EUGREENalliance<\/a>. Le but : r\u00e9pondre \u00e0 un appel \u00e0 projet visant \u00e0 r\u00e9aliser une application d\u2019aide \u00e0 la d\u00e9cision dans les domaines de la sant\u00e9, de la technologie, et des sciences sociales, \u00e0 l\u2019aide d\u2019une IA qui explique son raisonnement. <a href=\"https:\/\/t.co\/3cBHvh8kbF\">pic.twitter.com\/3cBHvh8kbF<\/a><\/p>&mdash; Universit\u00e9 d&#39;Angers (@UnivAngers) <a href=\"https:\/\/twitter.com\/UnivAngers\/status\/1750511531236704404?ref_src=twsrc%5Etfw\">January 25, 2024<\/a><\/blockquote><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script>\n<\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">25\/09\/2023 &#8211; Matin\u00e9e Musique &amp; IA<\/h2>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><a href=\"https:\/\/leria.univ-angers.fr\/?page_id=306\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/leria.univ-angers.fr\/wp-content\/uploads\/2023\/09\/affiche-1024x576.jpeg\" alt=\"\" class=\"wp-image-304\" style=\"width:614px;height:344px\" srcset=\"https:\/\/leria.univ-angers.fr\/wp-content\/uploads\/2023\/09\/affiche-1024x576.jpeg 1024w, https:\/\/leria.univ-angers.fr\/wp-content\/uploads\/2023\/09\/affiche-300x169.jpeg 300w, https:\/\/leria.univ-angers.fr\/wp-content\/uploads\/2023\/09\/affiche-768x432.jpeg 768w, https:\/\/leria.univ-angers.fr\/wp-content\/uploads\/2023\/09\/affiche-1536x864.jpeg 1536w, https:\/\/leria.univ-angers.fr\/wp-content\/uploads\/2023\/09\/affiche-500x281.jpeg 500w, https:\/\/leria.univ-angers.fr\/wp-content\/uploads\/2023\/09\/affiche.jpeg 1600w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n\n\n\n<p><a href=\"https:\/\/leria.univ-angers.fr\/?page_id=306\">Lien vers le programme, les pr\u00e9sentations et les photos de l&#8217;\u00e9v\u00e9nement<\/a><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><strong>24\/05\/2023 &#8211; Vorapong Suppakitpaisarn : On the maximum edge-pair embedding bipartite matching<\/strong><\/p>\n\n\n\n<p>Given a set of edge pairs in a complete bipartite graph, we want to find a bipartite matching that includes the maximum number of those edge pairs. While the problem has many applications to wireless localization and computer vision, to the best of our knowledge, there is no theoretical work for the problem. In this work, unless P = NP, we show that there is no constant approximation for the problem. Then, we consider two special cases of the problem. Suppose that k denotes the maximum number of input edge pairs such that a particular node can be in. Inspired by experimental results, the first case is for when k is not large. While there is a simple polynomial-time algorithm for the problem when k is one, we show that the problem is NP-hard when k is greater than one. We also devise an efficient O(k)-approximation algorithm for the problem. For the second case, every pair of nodes in the same partition of the input bipartite graph are labeled with one of \u03c7 colors. We want to match, between the two partitions, a pair of nodes to a pair of nodes with the same color. Denote n as the number of nodes, we give an O (\u221a\u03c7n)-approximation algorithm for this case<\/p>\n\n\n\n<p><strong>17\/04\/2023 &#8211; Beno\u00eet Delahaye<\/strong> : <strong>Mod\u00e9lisation et v\u00e9rification statistique pour les syst\u00e8mes Naturels<\/strong><\/p>\n\n\n\n<p>La mod\u00e9lisation et l&#8217;analyse de mod\u00e8les sont centrales dans toutes les disciplines scientifiques, mais les formalismes et techniques formelles d\u00e9velopp\u00e9es en Informatique th\u00e9orique sont souvent peu adapt\u00e9es aux probl\u00e9matiques des sciences &#8220;naturelles&#8221;. La param\u00e9trisation et l&#8217;analyse de stabilit\u00e9 de mod\u00e8le diff\u00e9rentiels sont des questions pratiques, issues de probl\u00e9matiques r\u00e9elles dans le cadre des syst\u00e8mes naturels, que les m\u00e9thodes formelles informatiques peinent \u00e0 appr\u00e9hender. Dans cet expos\u00e9, je pr\u00e9senterai comment la v\u00e9rification de mod\u00e8les statistique peut \u00eatre combin\u00e9e \u00e0 des m\u00e9thodes d&#8217;int\u00e9gration num\u00e9rique pour proposer des r\u00e9ponses \u00e0 ces questions dans un cadre g\u00e9n\u00e9rique tout en pr\u00e9servant des garanties formelles.<\/p>\n\n\n\n<p><strong>08\/03\/2023 &#8211; Malak Belkebir : Proposal of semantic models for the improvement of standard image processing methods based on inductive inference<\/strong>.<\/p>\n\n\n\n<p>Nowadays, imaging and artificial vision have become important fields of research due to their underneath applications. These last have reached a high level of usefulness thanks to the used techniques. For instance, deep learning, a well-known technique, has proven its capabilities in terms of theoretical and research-level results as well as practical applications. Nevertheless, despite the high accuracy that has been achieved by their techniques, most of them remain \u201cquantitative approaches\u201d,i.e. \u201cdata-driven approaches\u201d; their efficiency depends on the computational capacity and requires a large amount of data for training and testing. Furthermore, there are still many deficiencies, such as the semantic gap between the low-level visual information and high-level semantic knowledge, the recognition of complex scenes and so on. With the aim of providing less costly and more efficient solutions, the new trend is to make it possible for the aforementioned fields to support knowledge representation techniques i.e. \u201cqualitative- approaches\u201d, which is at first sight ontological. This presentation provides an overview of various research studies that have demonstrated the effectiveness of this combination, including formal methods, first-order logic, deep learning, and imaging. Additionally, it includes a contribution to this field, along with some results and a case study.<\/p>\n\n\n\n<p><strong>02\/03\/2023 &#8211; Javier Yuste : Automatic improvement of software quality: optimization strategies for software maintainability.<\/strong><\/p>\n\n\n\n<p>Search-Based Software Engineering is a research area that aims to tackle software engineering tasks as optimization problems. Among the problems in this area, we can find the Software Module Clustering Problem (SMCP), which has been proved to be NP-hard. This problem focuses on finding the best organization of a software project in terms of modularity. Since modular code is easier to understand, the objective of this problem is to increase the quality of software projects and thus reduce the costs associated to their maintenance. To tackle the SMCP, software projects are often modeled as graphs, representing the dependencies between different components of the code. To cluster the resulting graphs, we present two different algorithms based on the Greedy Randomized Adaptive Search Procedure and the Variable Neighborhood Search frameworks. Furthermore, we introduce some advanced strategies that enhance the efficiency of the proposed algorithms, accelerating the computation of the objective function and avoiding the exploration of unpromising solutions in the search space. Finally, we compare the proposed methods over a set of 124 real software projects, studying two objective functions: Modularization Quality (MQ) and the Function of Complexity Balance (FCB). The obtained results show that the proposed algorithms obtain better results than the previous state-of-the-art proposals. Moreover, the difference in the results is shown to be statistically significant with a p-value lower than 0.01, according to non-parametric statistical tests.<\/p>\n\n\n\n<p><strong>10\/01\/2023 &#8211; V\u00e9ronique Ventos : Nook : a new generation AI dedicated to the game of Bridge.<\/strong><\/p>\n\n\n\n<p>Plusieurs d\u00e9fis se posent aujourd\u2019hui \u00e0 l\u2019Intelligence Artificielle 1\/ v\u00e9ritable collaboration entre l\u2019humain et la machine 2\/ transparence et confiance dans les d\u00e9cisions 3\/ sobri\u00e9t\u00e9 \u00e9nerg\u00e9tique. Pour r\u00e9pondre \u00e0 ces d\u00e9fis, le laboratoire de recherche priv\u00e9 NukkAI a utilis\u00e9 comme bac \u00e0 sable le jeu de Bridge qui r\u00e9siste encore \u00e0 l\u2019IA le niveau des robots existants \u00e9tant tr\u00e8s loin de celui des meilleurs joueurs humains. Lors d\u2019un challenge organis\u00e9 les 25 et 26 Mars 2022 \u00e0 Paris, l\u2019IA de bridge Nook a battu 8 champions du monde de bridge. Au-del\u00e0 de cette premi\u00e8re mondiale, Nook permet de montrer l\u2019avantage de ne pas rester dans un cadre mono paradigme m\u00eame si celui-ci est tr\u00e8s \u00e0 la mode. En effet, notre robot est une IA hybride dont les modules proviennent de diff\u00e9rents paradigmes interagissant entre eux. Dans cette pr\u00e9sentation, nous commencerons par bri\u00e8vement d\u00e9crire NukkAI et ce que nous entendons par IA nouvelle g\u00e9n\u00e9ration. La seconde partie sera consacr\u00e9e aux notions de base du bridge et \u00e0 la description du challenge. Enfin, nous pr\u00e9senterons les diff\u00e9rents modules de recherche de Nook.<\/p>\n\n\n\n<p><strong>08\/12\/2022 &#8211; Fran\u00e7ois Olivier<\/strong><\/p>\n\n\n\n<p>The ASPMT tool generalizes the &#8220;Answer Set Programming&#8221; approach to allow reasoning Modulo a certain underlying Theory. The presentation will focus on the use of ASPMT with non-linear arithmetic constraints, as well as on the possible applications offered by this system, such as the modelling of human spatial reasoning in cognitive sciences.<\/p>\n\n\n\n<p><strong>27\/10\/2022 &#8211; Sylvain Lamprier : Apprentissage Statistique et Inf\u00e9rence Bay\u00e9sienne pour Donn\u00e9es S\u00e9quentielles et Relationnelles<\/strong>.<\/p>\n\n\n\n<p><strong>26\/08\/2022 &#8211; Tomasz Jastrzab : Parallel constraint solving<\/strong><\/p>\n\n\n\n<p>During the talk, selected parallel computing models will be shown along with their implementations. The constraint solving part of the talk will focus on solving the problem of nondeterministic automata inference using SAT-based models and solvers. The advantages and problems related to using parallel computing will be discussed.<\/p>\n\n\n\n<!-- ancien tableau des s\u00e9minaires sur la page des th\u00e8ses\n<figure class=\"wp-block-table is-style-stripes\" style=\"font-size:80%\"><table><thead><tr><th><\/th><th><\/th><th><\/th><th><\/th><\/tr><\/thead><tbody><tr><th>DATE<\/th><th>INTERVENANT<\/th><th>ETABLISSEMENT<\/th><th>TITRE<\/th><\/tr><tr><td>2021\/10\/21<\/td><td>ABREU Salvador<\/td><td>Universit\u00e9 d'Evora, Portugal<\/td><td>Parallel Hybrid Constraint-Based Computations: architectures for scalable performance<\/td><\/tr><tr><td>2020\/9\/24<\/td><td>LU Zhi<\/td><td>LERIA<\/td><td>Approches d\u2019Optimisation pour le Partitionnement de Graphe de Conductance Minimale<\/td><\/tr><tr><td>2020\/10\/22<\/td><td>ROBERT Adrian<\/td><td>LERIA<\/td><td><\/td><\/tr><tr><td>2020\/10\/22<\/td><td>ZHOU Jin Qing<\/td><td>LERIA<\/td><td><\/td><\/tr><tr><td>2020\/1\/24<\/td><td>REN Jintong<\/td><td>LERIA<\/td><td>A study of recombination Operators for the Cyclic Bandwith Problem<\/td><\/tr><tr><td>2020\/1\/24<\/td><td>DELAVERNHE Florian<\/td><td>LERIA<\/td><td>Planification de la recherche de cible mobile \u00e0 l'aide d'un r\u00e9seau de capteurs avec co\u00fbt de d\u00e9placement<\/td><\/tr><tr><td>2019\/6\/28<\/td><td>ROSSI Roberto<\/td><td>University of Edinburgh<\/td><td>Declarative statistics<\/td><\/tr><tr><td>2019\/11\/28<\/td><td>GLAVATSKIKH Marta<\/td><td>LERIA<\/td><td>A crucial role of chemical diversity in ML prediction of DFT molecular properties<\/td><\/tr><tr><td>2019\/11\/28<\/td><td>TALBOT Pierre<\/td><td>LS2N, Univ. de Nantes<\/td><td>Interpr\u00e9tation abstraite pour la combinaison de langage de contraintes<\/td><\/tr><tr><td>2019\/10\/25<\/td><td>HENAUX Vincent<\/td><td>LERIA<\/td><td>\u00c9volution de recherches locales stochastiques<\/td><\/tr><tr><td>2019\/10\/25<\/td><td>GOUDET Olivier<\/td><td>LERIA<\/td><td>Gradient Descent based Weight Learning for Grouping Problems: Application on Graph Coloring and Equitable Graph Coloring<\/td><\/tr><tr><td>2019\/1\/24<\/td><td>GUYET Thomas<\/td><td>IRISA Rennes<\/td><td>Mining sequential patterns with ASP<\/td><\/tr><tr><td>2018\/5\/31<\/td><td>SINGH Alok<\/td><td>University of Hyderabad<\/td><td>A Hyper-Heuristic Approach for Many-to-Many Hub Location-Routing Problem<\/td><\/tr><tr><td>2018\/5\/16<\/td><td>TARI Sara<\/td><td>LERIA<\/td><td>Strat\u00e9gies d'exploration de paysages de fitness : application \u00e0 la r\u00e9solution approch\u00e9e de probl\u00e8mes d'optimisation combinatoire<\/td><\/tr><tr><td>2018\/5\/16<\/td><td>DELAVERNHE Florian<\/td><td>LERIA<\/td><td>Ordonnancement re\u0301actif pour le suivi de cibles mobiles : de la robustesse a\u0300 la garantie de performance en ligne<\/td><\/tr><tr><td>2018\/4\/5<\/td><td>SHANG Zhen<\/td><td>LERIA<\/td><td>Multiple phase tabu search for bipartite boolean quadratic programming with partitioned variables<\/td><\/tr><tr><td>2018\/4\/5<\/td><td>WEI Zequn<\/td><td>LERIA<\/td><td>Learning based computational methods for complex combinatorial search problems<\/td><\/tr><tr><td>2018\/4\/5<\/td><td>LE CALVAR Th\u00e9o<\/td><td>LERIA<\/td><td>Ensemble de mode\u0300le explorables avec ATLC<\/td><\/tr><tr><td>2018\/1\/11<\/td><td>VEERAPEN Nada<\/td><td>University of Stirling<\/td><td>Les r\u00e9seaux d'optima locaux pour mod\u00e9liser les paysages de recherche<\/td><\/tr><tr><td>2018\/1\/11<\/td><td>VASCONCELLOS GAETE Claudia<\/td><td>LERIA<\/td><td>Etude des m\u00e9canismes de transformation de mod\u00e8les CSP\/SAT<\/td><\/tr><tr><td>2017\/6\/28<\/td><td>BLUM Christian<\/td><td>IIA, Spanish National Research Council<\/td><td>Construct, Merge, Solve &amp; Adapt : a general hybrid metaheuristic for combinatorial optimization<\/td><\/tr><tr><td>2017\/6\/1<\/td><td>TRAVERSON Hugo<\/td><td>LERIA<\/td><td>Apprentissage, synth\u00e8se et \u00e9valuation \u00e0 base de cartes concdeptuelles ontologiques<\/td><\/tr><tr><td>2017\/6\/1<\/td><td>SCHEPLER Xavier<\/td><td>LERIA<\/td><td>The stochastic discrete berth allocation problem<\/td><\/tr><tr><td>2017\/4\/6<\/td><td>ZHOU Yangming<\/td><td>LERIA<\/td><td>Opposition-based memetic search for the maximum diversity problem<\/td><\/tr><tr><td>2017\/4\/6<\/td><td>REN Jintong<\/td><td>LERIA<\/td><td>A study of recombination Operators for the Cyclic Bandwith Problem<\/td><\/tr><tr><td>2017\/3\/2<\/td><td>TARI Sara<\/td><td>LERIA<\/td><td>Recherche locale it\u00e9r\u00e9e bas\u00e9e sur le moins bon am\u00e9liorant<\/td><\/tr><tr><td>2017\/3\/2<\/td><td>CHAMBON Arthur<\/td><td>LERIA<\/td><td>Caract\u00e9risation de donn\u00e9es biologiques<\/td><\/tr><tr><td>2016\/7\/7<\/td><td>PAVONE Mario<\/td><td>University of Catania, Italy<\/td><td>How Old should be the Lifespan for Having a Proper Exploration?<\/td><\/tr><tr><td>2016\/6\/15<\/td><td>JANKEE Christopher<\/td><td>LISIC, Universit\u00e9 du Littoral C\u00f4te d'Opale<\/td><td>Portefolio de m\u00e9taheuristique en calcule distribu\u00e9 : strat\u00e9gies de s\u00e9lection et Fitness Cloud mod\u00e8le<\/td><\/tr><tr><td>2016\/12\/1<\/td><td>CHABANE Brahim<\/td><td>LERIA<\/td><td>R2-IBMOLS applied to a practical case of the multiobjective knapsack problem<\/td><\/tr><tr><td>2016\/12\/1<\/td><td>LEGEAY Marc<\/td><td>LERIA<\/td><td>Analyse diff\u00e9rentielle de r\u00e9seaux : un moyen d'\u00e9tudier la r\u00e9gulation par les transcrits anti-sens<\/td><\/tr><tr><td>2016\/11\/3<\/td><td>DESPORT Pierre<\/td><td>LERIA<\/td><td>Model and Combinatorial Optimization Methods for Tactical Planning in Closed-Loop Supply Chains<\/td><\/tr><tr><td>2016\/11\/3<\/td><td>ZHOU Yi<\/td><td>LERIA<\/td><td>Recherche de clique \u00e9quilibr\u00e9e de cardinalit\u00e9 maximale dans les graphes bipartis<\/td><\/tr><tr><td>2016\/10\/6<\/td><td>GARREAU Fabien<\/td><td>LERIA<\/td><td>Extension d'ASP pour traiter les logiques de descriptions dites l\u00e9g\u00e8res<\/td><\/tr><tr><td>2015\/6\/3<\/td><td>SINGH Alok<\/td><td>University of Hyderabad<\/td><td>Artificial Bee Colony Algorithm for Discrete Optimization Problems<\/td><\/tr><tr><td>2015\/4\/2<\/td><td>SCHAUB Torsten<\/td><td>Universit\u00e9 de Postdam<\/td><td>Answer Set Programming<\/td><\/tr><tr><td>2014\/5\/22<\/td><td>KORICHE Fr\u00e9d\u00e9ric<\/td><td>Universit\u00e9 d'Artois<\/td><td>Des experts aux bandits pour l\u2019optimisation combinatoire<\/td><\/tr><tr><td>2014\/4\/15<\/td><td>GUILLAUME Jean-Loup<\/td><td>Universit\u00e9 Pierre et Marie Curie<\/td><td>Communaut\u00e9s multi-ego-centr\u00e9es<\/td><\/tr><tr><td>2014\/4\/15<\/td><td>GACH Olivier<\/td><td>Universit\u00e9 du Mans<\/td><td>Communaut\u00e9s disjointes d\u00e9tect\u00e9es par la modularit\u00e9<\/td><\/tr><tr><td>2014\/3\/18<\/td><td>GARREAU Fabien<\/td><td>LERIA<\/td><td>Extension of ASP to cover fragments of light description<\/td><\/tr><tr><td>2014\/1\/30<\/td><td>GUZIOLOVSKI Carito<\/td><td>Meforbio, IRCCYN, Ecole Centrale de Nantes<\/td><td>Exhaustively characterizing feasible logic models of a signaling network using Answer Set Programming<\/td><\/tr><\/tbody><\/table><\/figure>-->\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>14\/05\/2024 &#8211; Yi ZHOU : Recent advances in algorithms for k-plex problems In the field of graph mining, the k-plex is a well-known extension of the basic clique model. A k-plex is nearly a clique except that each vertex is &hellip; <a href=\"https:\/\/leria.univ-angers.fr\/?page_id=290\">Continuer la lecture <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":12,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-290","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/leria.univ-angers.fr\/index.php?rest_route=\/wp\/v2\/pages\/290","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/leria.univ-angers.fr\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/leria.univ-angers.fr\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/leria.univ-angers.fr\/index.php?rest_route=\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/leria.univ-angers.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=290"}],"version-history":[{"count":12,"href":"https:\/\/leria.univ-angers.fr\/index.php?rest_route=\/wp\/v2\/pages\/290\/revisions"}],"predecessor-version":[{"id":402,"href":"https:\/\/leria.univ-angers.fr\/index.php?rest_route=\/wp\/v2\/pages\/290\/revisions\/402"}],"wp:attachment":[{"href":"https:\/\/leria.univ-angers.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=290"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}