86 research outputs found
The CLEF-2024 CheckThat! Lab: check-worthiness, subjectivity, persuasion, roles, authorities, and adversarial robustness.
No full textComunicació presentada a 46th European Conference on Information Retrieval, ECIR 2024, celebrada del 24 al 28 de març de 2024 a Glasgow, Regne UnitThe first five editions of the CheckThat! lab focused on the main tasks of the information verification pipeline: check-worthiness, evidence retrieval and pairing, and verification. Since the 2023 edition, it has been focusing on new problems that can support the research and decision making during the verification process. In this new edition, we focus on new problems and —for the first time— we propose six tasks in fifteen languages (Arabic, Bulgarian, English, Dutch, French, Georgian, German, Greek, Italian, Polish, Portuguese, Russian, Slovene, Spanish, and code-mixed Hindi-English): Task 1 estimation of check-worthiness (the only task that has been present in all CheckThat! editions), Task 2 identification of subjectivity (a follow up of CheckThat! 2023 edition), Task 3 identification of persuasion (a follow up of SemEval 2023), Task 4 detection of hero, villain, and victim from memes (a follow up of CONSTRAINT 2022), Task 5 Rumor Verification using Evidence from Authorities (a first), and Task 6 robustness of credibility assessment with adversarial examples (a first). These tasks represent challenging classification and retrieval problems at the document and at the span level, including multilingual and multimodal settings.The work of F. Haouari is supported by GSRA grant #GSRA6-1-0611-19074 from the Qatar National Research Fund. The work of T. Elsayed was made possible by NPRP grant #NPRP-11S-1204-170060 from the Qatar National Research Fund (a member of Qatar Foundation). The work of F. Alam, M. Hasanain and R. Suwaileh is partially supported by NPRP 14C-0916-210015 from the Qatar National Research Fund (a member of Qatar Foundation). The work of P. Przybyła is part of the ERINIA project, which has received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement No 101060930
CheckThat! at CLEF 2020: Enabling the automatic identification and verification of claims in social media
No full textWe describe the third edition of the CheckThat! Lab, which is part of the 2020 Cross-Language Evaluation Forum (CLEF). CheckThat! proposes four complementary tasks and a related task from previous lab editions, offered in English, Arabic, and Spanish. Task 1 asks to predict which tweets in a Twitter stream are worth fact-checking. Task 2 asks to determine whether a claim posted in a tweet can be verified using a set of previously fact-checked claims. Task 3 asks to retrieve text snippets from a given set of Web pages that would be useful for verifying a target tweet’s claim. Task 4 asks to predict the veracity of a target tweet’s claim using a set of potentially-relevant Web pages. Finally, the lab offers a fifth task that asks to predict the check-worthiness of the claims made in English political debates and speeches. CheckThat! features a full evaluation framework. The evaluation is carried out using mean average precision or precision at rank k for ranking tasks, and F1 for classification tasks
Exogenous application of salt (NaCl) inhibit antioxidative system in Cd-treated watercress (Nasturtium officinale R. Br.)
No full textInternational audienceThis research simulates conditions found in metal-contaminated sites also affected by a high concentration of salt. For these reasons, several exogenous doses of NaCl were used to treat Cd-stressed Nasturtium officinale R. Br. We have chosen Nasturtium officinale R. Br which is a hyper accumulator plant of metals (based on literature). Data suggested induction of oxidative stress under Cd treatment and demonstrated watercress's capacity to upregulate its antioxidative defense. Superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (GPX) activities were stimulated by Cd. Supplementation of (100, 200, 300 mM NaCl) simultaneously with 1 MCd to six weeks aged Nasturtium officinale R. Br caused growth inhibition, reduction of photosynthetic pigment contents and a significant increase of Malonyldialdehyde (MDA) and hydrogen peroxide (H2O2) ones in leaves. Increase of NaCl dose reduced Cd tenor in Nasturtium officinale leaves. Moreover, a dramatic lost of antioxidant system efficiency was detected in these plants. Rise of salinity concentration significantly inhibited SOD, CAT, APX and GPX activities in Cd-treated Nasturtium officinale R. Br
Overview of CheckThat! 2020: Automatic Identification and Verification of Claims in Social Media
No full textWe present an overview of the third edition of the CheckThat! Lab at CLEF 2020. The lab featured five tasks in two different languages: English and Arabic. The first four tasks compose the full pipeline of claim verification in social media: Task 1 on check-worthiness estimation, Task 2 on retrieving previously fact-checked claims, Task 3 on evidence retrieval, and Task 4 on claim verification. The lab is completed with Task 5 on check-worthiness estimation in political debates and speeches. A total of 67 teams registered to participate in the lab (up from 47 at CLEF 2019), and 23 of them actually submitted runs (compared to 14 at CLEF 2019). Most teams used deep neural networks based on BERT, LSTMs, or CNNs, and achieved sizable improvements over the baselines on all tasks. Here we describe the tasks setup, the evaluation results, and a summary of the approaches used by the participants, and we discuss some lessons learned. Last but not least, we release to the research community all datasets from the lab as well as the evaluation scripts, which should enable further research in the important tasks of check-worthiness estimation and automatic claim verification
Solving Medium to Large Sized Euclidean Generalized Minimum Spanning Tree Problems
No full textThe generalized minimum spanning tree problem is a generalization of the minimum spanning tree problem. This network design problems finds several practical applications, especially when one considers the design of a large-capacity backbone network connecting several individual networks. In this paper we study the performance of six neighborhood search heuristics based on tabu search and variable neighborhood search on this problem domain. Our principal finding is that a tabu search heuristic almost always provides the best quality solution for small to medium sized instances within short execution times while variable neighborhood decomposition search provides the best quality solutions for most large instances.
A Probabilistic Tabu Search Algorithm for the Generalized Minimum Spanning Tree Problem
No full textIn this paper we present a probabilistic tabu search algorithm for the generalized minimum spanning tree problem. The basic idea behind the algorithm is to use preprocessing operations to arrive at a probability value for each vertex which roughly corresponds to its probability of being included in an optimal solution, and to use such probability values to shrink the size of the neighborhood of solutions to manageable proportions. We report results from computational experiments that demonstrate the superiority of this method over the generic tabu search method.
The CLEF-2023 CheckThat! Lab: Checkworthiness, Subjectivity, Political Bias, Factuality, and Authority
No full textWe describe the sixth edition of the CheckThat! lab, part of the 2023 Conference and Labs of the Evaluation Forum (CLEF). The five previous editions of CheckThat! focused on the main tasks of the information verification pipeline: check-worthiness, verifying whether a claim was fact-checked before, supporting evidence retrieval, and claim verification. In this sixth edition, we zoom into some new problems and for the first time we offer five tasks in seven languages: Arabic, Dutch, English, German, Italian, Spanish, and Turkish. Task 1 asks to determine whether an item —text or text plus image— is check-worthy. Task 2 aims to predict whether a sentence from a news article is subjective or not. Task 3 asks to assess the political bias of the news at the article and at the media outlet level. Task 4 focuses on the factuality of reporting of news media. Finally, Task 5 looks at identifying authorities in Twitter that could help verify a given target claim. For a second year, CheckThat! was the most popular lab at CLEF-2023 in terms of team registrations: 127 teams. About one-third of them (a total of 37) actually participated
Contributions to the study of smoke flows in a building in case of fire
No full textCe travail de thèse est consacré à l’évaluation et l’amélioration des modèles à zones, utilisés dans l’ingénierie de la sécurité incendie pour simuler la propagation des fumées dans un bâtiment en situation d’incendie. Il a pour ambition d’améliorer la compréhension des écoulements des fumées dans un bâtiment. Le mémoire de thèse est divisé en deux parties. La première est essentiellement consacrée à l’état de l’art et à une évaluation de la capacité du code CFAST, code à zones largement utilisé dans l’ingénierie de la sécurité incendie, à simuler les écoulements de fumées dans un bâtiment. Le code à zones CFAST est confronté aux résultats d’une campagne expérimentale à échelle réelle réalisée dans un bâtiment d’habitation de type R+3. La seconde partie du manuscrit, plus académique, consiste à étudier les écoulements de fumée dans un bâtiment. Dans un premier temps, deux phénomènes sont étudiés : le phénomène de remplissage d’un local par des fumées d’incendie, et le phénomène de remplissage / vidange simultanés d’un local ventilé naturellement. Des modèles à zones permettant de décrire ces phénomènes sont présentés. Deux campagnes expérimentales ont été menées à échelle réduite sur des maquettes thermiques de locaux, afin d’étudier les deux phénomènes et d’évaluer et améliorer les modèles à zones. De plus, des simulations numériques complémentaires avec le code à champs FDS (Fire Dynamics Simulator) sont réalisées pour étendre le domaine d’étude du phénomène de remplissage. Enfin, des améliorations du modèle à zones sont proposées. Après l’étude des phénomènes liés aux écoulements de fumée dans un local unique, les écoulements de fumées dans une configuration multi-compartiments, constituée de deux locaux reliés par une cage d’escalier, sont étudiés expérimentalement à l’échelle du laboratoireThis work is devoted to the evaluation and improvement of zone models, used in fire safety engineering to simulate the smoke propagation in a building in a fire situation. It aims at improving the understanding of the smoke flow in a building. The PhD work is divided into two parts. The first part is essentially devoted to a bibliographical survey and an evaluation of the ability of a zone code CFAST, widely used in fire safety engineering, to simulate smoke flows in a building. Numerical results with CFAST are compared with the data of a real-scale experimental campaign carried out on a three-storey residential building. The second part, more academic, consists of studying the smoke flows in a building. Two phenomena are first studied, namely the smoke filling of a room, and the simultaneous filling and emptying of a naturally ventilated room. Zone models describing these phenomena are presented. Two experimental campaigns are conducted on reduced scale room models, in order to study the two phenomena and to evaluate and improve the zone models. Furthermore, numerical simulations with the CFD code FDS (Fire Dynamics Simulator) are performed to extend the study field of the smoke filling. Finally, improvements to the zone model are proposed. After studying the phenomena related to smoke flows in a single room, the smoke flows in a multi-compartment configuration, consisting of two rooms connected by a stairwell, are experimentally studied at the laboratory scal
Contributions à l'étude des écoulements de fumées dans un bâtiment en situation d'incendie
No full textThis work is devoted to the evaluation and improvement of zone models, used in fire safety engineering to simulate the smoke propagation in a building in a fire situation. It aims at improving the understanding of the smoke flow in a building. The PhD work is divided into two parts. The first part is essentially devoted to a bibliographical survey and an evaluation of the ability of a zone code CFAST, widely used in fire safety engineering, to simulate smoke flows in a building. Numerical results with CFAST are compared with the data of a real-scale experimental campaign carried out on a three-storey residential building. The second part, more academic, consists of studying the smoke flows in a building. Two phenomena are first studied, namely the smoke filling of a room, and the simultaneous filling and emptying of a naturally ventilated room. Zone models describing these phenomena are presented. Two experimental campaigns are conducted on reduced scale room models, in order to study the two phenomena and to evaluate and improve the zone models. Furthermore, numerical simulations with the CFD code FDS (Fire Dynamics Simulator) are performed to extend the study field of the smoke filling. Finally, improvements to the zone model are proposed. After studying the phenomena related to smoke flows in a single room, the smoke flows in a multi-compartment configuration, consisting of two rooms connected by a stairwell, are experimentally studied at the laboratory scaleCe travail de thèse est consacré à l’évaluation et l’amélioration des modèles à zones, utilisés dans l’ingénierie de la sécurité incendie pour simuler la propagation des fumées dans un bâtiment en situation d’incendie. Il a pour ambition d’améliorer la compréhension des écoulements des fumées dans un bâtiment. Le mémoire de thèse est divisé en deux parties. La première est essentiellement consacrée à l’état de l’art et à une évaluation de la capacité du code CFAST, code à zones largement utilisé dans l’ingénierie de la sécurité incendie, à simuler les écoulements de fumées dans un bâtiment. Le code à zones CFAST est confronté aux résultats d’une campagne expérimentale à échelle réelle réalisée dans un bâtiment d’habitation de type R+3. La seconde partie du manuscrit, plus académique, consiste à étudier les écoulements de fumée dans un bâtiment. Dans un premier temps, deux phénomènes sont étudiés : le phénomène de remplissage d’un local par des fumées d’incendie, et le phénomène de remplissage / vidange simultanés d’un local ventilé naturellement. Des modèles à zones permettant de décrire ces phénomènes sont présentés. Deux campagnes expérimentales ont été menées à échelle réduite sur des maquettes thermiques de locaux, afin d’étudier les deux phénomènes et d’évaluer et améliorer les modèles à zones. De plus, des simulations numériques complémentaires avec le code à champs FDS (Fire Dynamics Simulator) sont réalisées pour étendre le domaine d’étude du phénomène de remplissage. Enfin, des améliorations du modèle à zones sont proposées. Après l’étude des phénomènes liés aux écoulements de fumée dans un local unique, les écoulements de fumées dans une configuration multi-compartiments, constituée de deux locaux reliés par une cage d’escalier, sont étudiés expérimentalement à l’échelle du laboratoir
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