Scientific Publications of the University of Toulouse II Le Mirail
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Dorothea Brooke, Gwendolyn Harleth and Hetty Sorrel on the Brink of the Impossible: George Eliot and the Female Bildungsroman
No full textInternational audienceThis paper examines the tension between ambition and failure in the trajectories of the female protagonists in three George Eliot novels—Hetty Sorrel in Adam Bede (1859), Dorothea Brooke in Middlemarch (1871-72), and Gwendolyn Harleth in Daniel Deronda (1876). Building on Franco Moretti’s notion of a ‘distinct female Bildungsroman’, I argue that these characters’ development follows a similar three-step structure as they navigate the constraints of gender, class, and socioeconomic status. The dialectical interplay between ambition and coercion sustains the narratives on the brink of possibility and impossibility, while Eliot’s narrative choices challenge traditional forms of the Bildungsroman, offering a critique of the genre as it applies to women.Cet article examine la tension entre ambition et échec dans les trajectoires des protagonistes féminines de trois romans de George Eliot : Hetty Sorrel dans Adam Bede (1859), Dorothea Brooke dans Middlemarch (1871-1872) et Gwendolyn Harleth dans Daniel Deronda (1876). En m’appuyant sur la notion de Franco Moretti d’un « Bildungsroman féminin distinct », je soutiens que le développement de ces personnages suit une structure similaire en trois étapes, alors qu’elles naviguent à travers les contraintes de genre, de classe et de statut socio-économique. L’interaction dialectique entre ambition et coercition maintient les récits à la limite du possible et de l’impossible, tandis que les choix narratifs d’Eliot remettent en question les formes traditionnelles du Bildungsroman, offrant ainsi une critique du genre tel qu’il s’applique aux femmes
Young measure relaxation gaps for controllable systems with smooth state constraints
No full textIn this article, we tackle the problem of the existence of a gap corresponding to Young measure relaxations for state-constrained optimal control problems. We provide a counterexample proving that a gap may occur in a very regular setting, namely for a smooth controllable system state constrained to the closed unit ball, provided that the Lagrangian density (i.e., the running cost) is non-convex in the control variables. The example is constructed in the setting of sub-Riemannian geometry with the core ingredient being an unusual admissible curve that exhibits a certain form of resistance to state-constrained approximation. Specifically, this curve cannot be approximated by neighboring admissible curves while obeying the state constraint due to the intricate nature of the dynamics near the boundary of the constraint set. Our example also presents an occupation measure relaxation gap.23 pages, 2 figure
Scanning and active sampling behaviours emerge from conserved insect neural circuits
No full textNavigating insects often pause and rotate to sample their surroundings, behaviours termed scanning. These and other active sampling behaviours embody navigational uncertainty, and are key for spatial learning, yet their neural basis remains unclear and existing models impose scanning behaviours rather than explaining its emergence. Here, we show that scanning can emerge spontaneously from the same conserved neural circuits used for goal-directed navigation, without requiring a specialized scanning module. We built a biologically grounded model combining central complex (CX) steering, lateral accessory lobe (LAL) oscillators, and stochastic inhibition of forward speed. This minimal system produced diverse, realistic scan dynamics; saccades, fixations and reversals, whose features were qualitatively compared to high-speed video recordings of Melophorus bagoti scanning. Detailed analysis of these natural scans confirmed model predictions, including how scan structure depends on oscillator phase, goal-heading deviation, and navigational uncertainty. Furthermore, the model reveals that simple modulation of forward speed unifies a broad range of behaviors across ant species, from dashes to smooth oscillatory trajectories to pirouettes and voltes. Crucially, it establishes a general distributed control principle; where forward speed acts as a single adjustable parameter regulating the balance between goal-driven exploitation and information-seeking exploration, without requiring centralized decision-making processes
Is this scenery worth exploring? Insight into the visual encoding of navigating ants
No full textInternational audienceSolitary foraging insects such as desert ants rely heavily on vision for navigation. Although ants can learn visual scenes, it is unclear what cues they use to decide whether a scene is worth exploring at the first place. To investigate this, we recorded the motor behaviour of Cataglyphis velox ants navigating in a virtual reality setup and measured their lateral oscillations in response to various unfamiliar visual scenes under both closed-loop and open-loop conditions. In naturalistic-looking panorama, ants display regular oscillations as observed outdoors, allowing them to efficiently scan the scenery. Manipulations of the virtual environment revealed distinct functions served by dynamic and static cues. Dynamic cues, mainly rotational optic flow, regulated the amplitude of oscillations but not their regularity. Conversely, static cues had little impact on the amplitude but were essential for producing regular oscillations. Regularity of oscillations decreased in scenes with only horizontal, only vertical or no edges, but was restored in scenes with both edge types together. The actual number of edges, the visual pattern heterogeneity across azimuths, the light intensity or the relative elevation of brighter regions did not affect oscillations. We conclude that ants use a simple but functional heuristic to determine whether the visual world is worth exploring, relying on the presence of at least two different edge orientations in the scene
L’Algérie contemporaine au prisme de ses marges : re-constructions identitaires, migrations et expériences de la subalternité
No full textNé de la volonté de prolonger les réflexions partagées lors d’une journée d’études qui s’est tenue à la MMSH en juin 2024, ce dossier propose d’aborder l’Algérie contemporaine à partir de ses marges – territoriales, sociales, linguistiques, mémorielles ou politiques – en s’intéressant aux manières dont se recomposent les identités, se vivent les rapports de pouvoir et se déploient les expériences de la subalternité. Les contributions croisent enquêtes de terrain, analyses historiques, géographiques, sociologiques et anthropologiques, et mobilisent une pluralité de matériaux (archives, ethnographies, récits biographiques, littérature, arts, analyses filmiques, etc.).<brWDossier en accès libre à cette adresse : https://espritcritique.hypotheses.org/541
La Dama de Elche: cómo nace un icono
No full textInternational audienceDiscovered in August 1897, the Lady of Elche quickly became a genuine symbol of Iberian art, supplanting the ex-votos from the Cerro de los Santos that had previously attracted the attention of the academic community, in particular the Great Lady Offerant. We propose to review the process by which the bust of the Alcudia of Elche became an icon of Iberian art, focusing on three main factors: firstly, the role played by the communication strategy implemented by Léon Heuzey and Pierre Paris in the months following its discovery; secondly, its rapid exhibition in the Louvre, which gave the sculpture and the art to which it belongs unprecedented visibility and legitimacy; and thirdly, Pierre Paris's account of its discovery and purchase, a novelistic discourse in which the facts blend with personal emotions tinged with mysticism.Descubierta en agosto de 1897, la Dama de Elche se impuso rápidamente como un icono representativo del arte ibérico, desplazando a los exvotos del Cerro de los Santos que hasta entonces habían atraído la atención de la comunidad científica, en particular la Gran Dama Oferente. Nos proponemos repasar las etapas que llevaron a que el busto de la Alcudia de Elche se convirtiera en un icono del arte ibérico, centrándonos en tres factores principales: en primer lugar, el papel desempeñado por la verdadera estrategia de comunicación puesta en marcha por Léon Heuzey y Pierre Paris en los meses que siguieron a su descubrimiento; en segundo lugar, su rápida exposición en el Louvre, que dio a la escultura y al arte al que pertenece una visibilidad y una legitimidad sin precedentes; y, por último, el relato de Pierre Paris sobre su descubrimiento y su compra, un discurso novelesco en el que los hechos se mezclan con emociones personales teñidas de misticismo.Découverte en août 1897, la Dame d’Elche s’est rapidement imposée comme un véritable symbole de l’art ibérique, supplantant les ex-voto du Cerro de los Santos qui avaient jusqu’à cette date retenu l’attention de la communauté scientifique, en particulier la Grande Dame Offrante. Nous nous proposons de revenir sur les étapes qui ont fait du buste de l’Alcudia d’Elche une icône de l’art ibérique en insistant sur trois facteurs principaux : d’une part, le rôle joué par la véritable stratégie de communication mise en œuvre par Léon Heuzey et Pierre Paris dans les mois qui suivent sa découverte ; d’autre part, sa rapide exposition au Louvre qui donne à la sculpture et à l’art auquel elle se rattache une visibilité et une légitimité inédites ; enfin, le récit de sa découverte et de son achat élaboré par Pierre Paris, un discours romanesque dans lequel les faits se mêlent à des émotions personnelles teintées de mysticisme
Optimization landscape of L0-Bregman relaxations
No full textIn this paper, we study (noisy) linear systems, and their ℓ 0 -regularized optimization problems, coupled with general data fidelity terms. Recent approaches for solving this class of problems have proposed to consider non-convex exact continuous relaxations that preserve global minimizers while reducing the number of local minimizers. Within this framework, we consider the class of ℓ 0 -Bregman relaxations, and establish sufficient conditions under which a critical point is isolated in terms of sparsity, in the sense that any other critical point has a strictly larger cardinality. In this way, we ensure a form of uniqueness in the solution structure. Furthermore, we analyze the exact recovery properties of such exact relaxations. To that end, we derive conditions under which the oracle solution (i.e., the one sharing the same support as the ground-truth) is the unique global minimizer of the relaxed problem, and is isolated in terms of sparsity. Our analysis is primarily built upon a novel property we introduce, termed the Bregman Restricted Strong Convexity. Finally, we specialize our general results to both sparse Gaussian (least-squares) and Poisson ((generalized) Kullback-Leibler divergence) regression problems. In particular, we show that our general analysis sharpens existing bounds for the LS setting, while providing an entirely new result for the KL case
Localization for transportation and urban planning in smart cities: interest, challenges, and solutions
No full textInternational audienceThe concept of a smart city represents an innovative approach to urban development, aiming to enhance residents' quality of life by making cities more adaptable and efficient through the integration of advanced technologies. In recent years, the Internet of Things (IoT) has been widely applied in various smart city domains, including communication, healthcare, and transportation. However, localization has emerged as one of the key challenges in IoT implementation. Localization plays a crucial role in smart city development, as it is essential for effective urban planning, traffic management, and optimizing public transportation routes. Accurate location data enable personalized services for citizens, such as activity recommendations and real-time alerts about local events. Furthermore, by optimizing travel and improving resource management, localization contributes to urban sustainability by reducing waste and enhancing overall efficiency. This research makes several contributions. First, it examines the significance of localization in smart cities and highlights the associated challenges. Next, it explores various indoor and outdoor localization technologies, analyzing their advantages and disadvantages while providing a comparative assessment. The manuscript also classifies communication networks within smart cities, detailing their characteristics. Additionally, it discusses various machine-learning algorithms used to address localization challenges. Finally, it reviews related works in the field, providing insights into existing solutions and future research directions.</div
Les Joueuses d'osselets d'Alexandros Athenaios Histoire d'un tableau
No full textInternational audienc
A modified Crank-Nicolson scheme for the Vlasov-Poisson system with a strong external magnetic field
No full textWe propose and study a Particle-In-Cell (PIC) method based on the Crank-Nicolson time discretization for the Vlasov-Poisson system with a strong and inhomogeneous external magnetic field with fixed direction, where we focus on the motion of particles in the plane orthogonal to the magnetic field. In this regime, the time step can be subject to stability constraints related to the smallness of Larmor radius and plasma frequency [21]. To avoid this limitation, our approach is based on numerical schemes [9, 10, 12], providing a consistent PIC discretization of the guiding-center system taking into account variations of the magnetic field.We carry out some theoretical proofs and perform several numerical experiments to validate the method and its underlying concepts.</p