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Educative platforms are at the heart of the development of online education. They can not only be reduced to technological aspects. Underlying models impact teaching and learning from the preparing of lessons to the learning sessions. Research related to these platforms are numerous and their stakes are important. For these reasons, we launched a call to a special issue on "Designs and uses of educative platforms" An educative platform is a computer system designed to automate various functions relating to the organization of the course, to the management of their content, to the monitoring of learners and supervision of persons in charge of various formations (Office de la langue française, 2005). So educative platforms are Learning Management Systems (LMS) which are specific to education contexts.
The title of this essay, Induced perversity, La perversidad inducida (in Spanish), refers to the side effects of sharing information on social media when it turns out to be false; or when judgments are made about people, events, companies, or facts that can produce effects often leading to consequences that were not initially foreseen. In digital environments, on the internet of linked data, harrassment politics and the cancellation culture are not isolated phenomena; they should be related to the evolution of the web, the emergence of the platform-driven economy, and the change of users' behaviour. Risks are not only a product of technology or the emergence of artificial intelligence. Ethical problems arise in a hybrid society, where the adaptation of human behavior to human-machine interaction (HMI), and the ethical, social, and legal ways of regulating them have yet to be learned. This contribution complements the contents of the article: La regimentacion tecnologica. Inteligencia artificial, fascismo, agresionn y sociedad democratica. TeKnoKultura. Revista de Cultura Digital y Movimientos Sociales, no 22, 2-2025, monografico sobre poder y politica de la inteligencia artificial.
The proximal gradient method is a splitting algorithm for the minimization of the sum of two convex functions, one of which is smooth. It has applications in areas such as mechanics, inverse problems, machine learning, image reconstruction, variational inequalities, statistics, operations research, and optimal transportation. Its formalism encompasses a wide variety of numerical methods in optimization such as gradient descent, projected gradient, iterative thresholding, alternating projections, the constrained Landweber method, as well as various algorithms in statistics and sparse data analysis. This paper aims at providing an account of the main properties of the proximal gradient method and to discuss some of its applications. --- La méthode du gradient proximé est un algorithme d'éclatement pour la minimisation de la somme de deux fonctions convexes, dont l'une est lisse. Elle trouve des applications dans des domaines tels que la mécanique, le traitement du signal, les problèmes inverses, l'apprentissage automatique, la reconstruction d'images, les inéquations variationnelles, les statistiques, la recherche opérationnelle et le transport optimal. Son formalisme englobe une gra
We consider the free boundary problem for a two-dimensional, incompressible, perfect, irrotational liquid drop of nearly circular shape with capillarity: that is, we consider the 2D version of the 3D capillary drop problem treated in Baldi-Julin-La Manna [11] and Baldi-La Manna-La Scala [12]. In particular, we derive its Craig-Sulem formulation firstly over the circle, then over the one-dimensional flat torus; the arising equations are similar to the pure capillary Water Waves for the ocean problem, apart from conformal factors and additional terms due to curvature terms. Then, we show its Hamiltonian structure and we derive constants of motions from symmetries, one of which is the invariance by the torus action. Thanks to this invariance, we show the existence of orbits of rotating wave solutions (which are the analogous of travelling waves of the ocean problem) by bifurcation from multiple eigenvalues in the spirit of Moser-Weinstein [44, 56] and Craig-Nicholls [22] variational approaches; in particular, we can parametrize such orbits by the angular momentum, and for each value of it they are unique. This will imply that each orbit is generated by symmetric rotating waves.
Excitonic insulators are electronically-driven phases of matter characterized by the spontaneous condensation of electron-hole pairs. Here we show that La$_3$Cd$_2$As$_6$ undergoes a transition at $T_{0}=278$ K to a highly insulating state with no accompanying structural transition. We observe quasi-two-dimensional electrical transport and charge fluctuations consistent with an electronic transition enabled by enhanced Coulomb interactions. Density functional theory calculations are unable to replicate the insulating ground state. Our results support the opening of a gap by excitonic effects at $T_{0}$, placing La$_3$Cd$_2$As$_6$ as a rare example of a bulk excitonic insulator.
This paper revisits camera pose estimation through the lens of self-supervised pretraining, focusing on inverse-dynamics pretraining as a scalable alternative to the current trend of fully supervised training with 3D annotations. Concretely, we employ inverse- and forward-dynamics models to learn latent action representations, similar to Genie from large-scale driving videos. Our idea is simple yet effective. Existing methods use latent actions in their original capacity, that is, as action conditioning of world-models or as proxies of robot action parameters in policy networks. Our method, dubbed LA-Pose, repurposes the latent action features as inputs to a camera pose estimator, finetuned on a limited set of high-quality 3D annotations. This formulation enables accurate and generalizable pose prediction while maintaining feed-forward efficiency. Extensive experiments on driving benchmarks show that LA-Pose achieves competitive and even superior performance to state-of-the-art methods while using orders of magnitude less labeled data. Concretely, on the Waymo and PandaSet benchmarks, LA-Pose achieves over 10% higher pose accuracy than recent feed-forward methods. To our knowledge,
In this expository article, we study the relation between the boolean functions and the hypercontractivity theorems of Aline Bonami. We focus on the social choice theory, and present some of the most important results in the area, such as the Friedgut-Kalai-Naor (FKN) and the Kahn-Kalai-Linial (KKL) theorems, and the famous Fourier Entropy/Influence conjecture. -- En este artículo expositivo estudiamos la relación entre las funciones booleanas y los teoremas de hipercontractividad de Aline Bonami. Nos concentramos en la teoría de la elección social, y presentamos algunos de los resultados más importantes en el área como los teoremas de Friedgut-Kalai-Naor (FKN) y de Kahn-Kalai-Linial (KKL), y la famosa conjetura Entropíıa de Fourier/Influencia.
The territory of La Mancha, its rural areas, and its landscapes suffer a kind of atherosclerosis ("the silent killer") because of the increase in artificial surfaces, the fragmentation of the countryside by various infrastructures, the abandonment of small and medium-sized farms and the loss of agricultural, material, and intangible heritage. At the same time, agricultural industrialization hides, behind a supposed productive efficiency, the deterioration of the quantitative and qualitative ecological status of surface and groundwater bodies, and causes air pollution, greenhouse gas emissions, loss of soil fertility, drainage and plowing of wetlands, forgetfulness of the ancestral environmental heritage, of the emergence of uses and customs of collective self-government and reduction of the adaptive capacity of traditional agroecosystems. This work aims, firstly, to shed light on the true costs of the main causes of environmental degradation in the territory of La Mancha, while deteriorating relations between rural and urban areas and determining the loss of territorial identity of La Mancha. the population. In addition, drivers of change toward a more sustainable social, economic,
Nous montrons qu'un raffinement du théorème de Siegel sur les points entiers de courbes algébriques impliquerait la conjecture abc de Masser-Oesterlé. Nous formulons une hypothèse "Siegel uniforme" qui est une majoration de la hauteur des points S-entiers de la courbe, en termes du corps de rationalité et de l'ensemble de places S. La validité de l'hypothèse pour une quelconque courbe algébrique de caractéristique d'Euler-Poincaré strictement négative, impliquerait une version de la conjecture abc. Ceci étend aux points S-entiers des résultats précédents de L. Moret-Bailly, et est en quelque sorte, un énoncé réciproque de ce que nous avons montré dans math.NT/0408168, en suivant les idées proposées par N. Elkies. Le principal outil géométrique employé est un théorème de G.V. Belyi. Nous montrons aussi quelques versions inconditionnelles de ces énoncés : un résultat allant dans le sens de la conjecture abc, valable sur tout corps de nombres, ainsi que des bornes pour la hauteur des solutions en S-entiers de certaines équations diophantiennes classiques.
Hierarchical multi-label text classification (HMTC) has been gaining popularity in recent years thanks to its applicability to a plethora of real-world applications. The existing HMTC algorithms largely focus on the design of classifiers, such as the local, global, or a combination of them. However, very few studies have focused on hierarchical feature extraction and explore the association between the hierarchical labels and the text. In this paper, we propose a Label-based Attention for Hierarchical Mutlti-label Text Classification Neural Network (LA-HCN), where the novel label-based attention module is designed to hierarchically extract important information from the text based on the labels from different hierarchy levels. Besides, hierarchical information is shared across levels while preserving the hierarchical label-based information. Separate local and global document embeddings are obtained and used to facilitate the respective local and global classifications. In our experiments, LA-HCN outperforms other state-of-the-art neural network-based HMTC algorithms on four public HMTC datasets. The ablation study also demonstrates the effectiveness of the proposed label-based att
Large language models, such as the well-known ChatGPT, have brought about an unexpected revolution in the field of artificial intelligence. On the one hand, they have numerous practical applications and enormous potential still to be explored. On the other hand, they are also the subject of debate from scientific, philosophical, and social perspectives: there are doubts about the exact mechanisms of their functioning and their actual capacity for language comprehension, and their applications raise ethical dilemmas. In this chapter, we describe how this technology has been developed and the fundamentals of its operation, allowing us to better understand its capabilities and limitations and to introduce some of the main debates surrounding its development and use. -- Los grandes modelos de lenguaje, como el conocido ChatGPT, han supuesto una inesperada revolución en el ámbito de la inteligencia artificial. Por un lado, cuentan con multitud de aplicaciones prácticas y un enorme potencial todavía por explorar. Por otro lado, son también objeto de debate, tanto desde el punto de vista científico y filosófico como social: hay dudas sobre los mecanismos exactos de su funcionamiento y su
The identity of the famous place of La Mancha appearing at the Quijote is an unknown with a history almost as long as that of the famous book by Miguel de Cervantes. This work analyzes data obtained from a Geographic Information System and compares the results with those of the previous works. Three different variables with two possible values each are considered: time or space data, 3 or 4 reference points, and the commonly used distances to the place of La Mancha or a set of recently proposed ones. The village in the Campo de Montiel which is closest to be the place of La Mancha happens to be Carrizosa or Villanueva de los Infantes, depending on the configuration, with the latter being the solution for the configuration in which the relative errors are the smallest and the second candidate village is furthest from the first. ----- La identidad del famoso lugar de la Mancha que aparece en El Quijote es una incógnita con una historia casi tan larga como la publicación de la famosa obra de Miguel de Cervantes. Este trabajo analiza datos obtenidos mediante un Sistema de Información Geográfica y compara los resultados con los de los trabajos anteriores. Se consideran tres variables di
This work describes the rescue and enhancement of several thousand spectrophotometric plates from the La Plata Observatory. These plates and their attached handwritten documents, date from the beginning of the 20th century and contain information on observations made at different observatories around the world. Due to their fragility and the inevitable deterioration produced by the passage of time, they are being cleaned up, recovered and digitized. The information contained in the plates has a high scientific value and, based on a comparison of an old spectrum with a current one, part of the history of the star can be reconstructed. Through the ReTrOH project, we seek to translate the document into an appropriate format, preserve and disseminate that knowledge, and also recover the scientific project and the historical and personal context of the observers. The digitized spectra are available in the virtual repository (SEDICI) of the UNLP.
La plupart des etoiles variables qui pulsent avec grande amplitude, telles les cepheides, ont un comportement tres regulier et periodique. Mais juste a cote d'elles dans le diagramme Hertzsprung-Russell, se trouve un groupe d'etoiles variables dotees de courbes de lumiere tres irregulieres. A l'aide d'une technique de reconstruction de flot appliquee aux donnees d'observation astronomiques de plusieurs de ces etoiles, on montre que la dynamique sous-jacente est chaotique et de faible dimension, ce qui peut surprendre a cause de la violence de ces pulsations. En plus a l'aide d'une linearisation du flot on deduit que le mecanisme physique de la pulsation consiste en l'interaction entre deux modes vibratoires (vraisemblablement radiaux), l'un lineairement instable, de frequence f_0, et l'autre stable, mais de frequence \~2f_0 (soit un scenario a la Shilnikoff generalise).
In this paper we characterise the smoothness of the nested Quot scheme of points of a smooth variety, namely the moduli space parametrising flags of $0$-dimensional quotients of a fixed locally free sheaf. Our results extend Cheah's classification of smooth nested Hilbert schemes. -- Dans cet article on caractérise la lissité du schéma Quot ponctuel emboîté d'une variété lisse, c'est-à-dire l'espace de modules paramétrant les drapeaux de quotients de dimension $0$ d'un faisceau localement libre fixé. Nos résultats étendent la classification de Cheah concernant les schémas de Hilbert ponctuels emboîtés.
Context. The discovery and tracking of 2018 LA marks only the third instance in history that the parent body of a fireball has been identified before its eventual disintegration in our atmosphere. The subsequent recovery of meteorites from 2018 LA was only the second time materials from outer space that reached the ground could be linked with certitude to a particular minor body. However, meteoroids like 2018 LA and its forerunners, 2008 TC3 and 2014 AA, are perhaps fragments of larger members of the near-Earth object (NEO) population. As the processes leading to the production of such fragments are unlikely to spawn just one meteoroid per event, it is important to identify putative siblings and plausible candidates from which the observed meteoroids might have originated. Aims. Here, we study the pre-impact orbital evolution of 2018 LA to place this meteoroid within the dynamical context of other NEOs that follow similar trajectories. Methods. Our statistical analyses are based on the results of direct N-body calculations that use the latest orbit determinations and include perturbations by the eight major planets, the Moon, the barycentre of the Pluto-Charon system, and the three
Apollo meteoroid 2018 LA has become only the third natural object ever to be discovered prior to causing a meteor airburst and just the second one to have its meteorites recovered (at Botswana's Central Kalahari Game Reserve). Here, we use the latest orbit determination of 2018 LA (solution date 18-July-2018) to search for minor bodies moving in paths comparable to that of 2018 LA using the D-criteria, which are metrics to study orbit similarity, and N-body simulations. Our results further confirm the existence of a dynamical grouping of asteroids that might be related to 2018 LA and show that the impactor could be a recent fragment spawned by a larger object, the 550-m wide, potentially hazardous asteroid (454100) 2013 BO73. Spectroscopic observations of 454100 during its next flyby with our planet (brightest at an apparent visual magnitude of 18.4 on 2018 mid-November) may confirm or deny a putative similar chemical composition to that of the recovered meteorites of 2018 LA.
Fine-tuning multi-turn dialogue systems requires high-quality supervision but often suffers from degraded performance when exposed to low-quality data. Supervision errors in early turns can propagate across subsequent turns, undermining coherence and response quality. Existing methods typically address data quality via static prefiltering, which decouples quality control from training and fails to mitigate turn-level error propagation. In this context, we propose ReSURE (Regularizing Supervision UnREliability), an adaptive learning method that dynamically down-weights unreliable supervision without explicit filtering. ReSURE estimates per-turn loss distributions using Welford's online statistics and reweights sample losses on the fly accordingly. Experiments on both single-source and mixed-quality datasets show improved stability and response quality. Notably, ReSURE enjoys positive Spearman correlations (0.21 ~ 1.0 across multiple benchmarks) between response scores and number of samples regardless of data quality, which potentially paves the way for utilizing large-scale data effectively. Code is publicly available at https://github.com/Elvin-Yiming-Du/ReSURE_Multi_Turn_Training.
The graded Iwahori--Matsumoto involution $\mathbb{IM}$ is an algebra involution on a graded Hecke algebra closely related to the more well-known Iwahori--Matsumoto involution on an affine Hecke algebra. It induces an involution on the Grothendieck group of complex finite-dimensional representations of $\mathbb{H}$. When $\mathbb{H}$ is a geometric graded Hecke algebra (in the sense of Lusztig) associated to a connected complex reductive group $G$, the irreducible representations of $\mathbb{H}$ are parametrised by a set $\mathcal{M}$ consisting of certain $G$-conjugacy classes of quadruples $(e,s,r_0,ψ)$ where $r_0 \in \mathbb{C}$, $e \in \mathrm{Lie}(G)$ is nilpotent, $s \in \mathrm{Lie}(G)$ is semisimple, and $ψ$ is some irreducible representation of the group of components of the simultaneous centraliser of $(e,s)$ in $G$. Let $\bar Y$ be an irreducible tempered representation of $\mathbb{H}$ with real infinitesimal character. Then $\mathbb{IM}(\bar Y) = \bar Y(e',s,r_0,ψ')$ for some $(e',s,r_0,ψ') \in \mathcal{M}$. The main result of this paper is to give an explicit algorithm that computes the $G$-orbit of $e'$ for $G = \mathrm{Sp}(2n,\mathbb{C})$ and $G = \mathrm{SO}(N,\mathb
One strength of modern language models is their ability to incorporate information from a user-input context when answering queries. However, they are not equally sensitive to the subtle changes to that context. To quantify this, Du et al. (2024) gives an information-theoretic metric to measure such sensitivity. Their metric, susceptibility, is defined as the degree to which contexts can influence a model's response to a query at a distributional level. However, exactly computing susceptibility is difficult and, thus, Du et al. (2024) falls back on a Monte Carlo approximation. Due to the large number of samples required, the Monte Carlo approximation is inefficient in practice. As a faster alternative, we propose Fisher susceptibility, an efficient method to estimate the susceptibility based on Fisher information. Empirically, we validate that Fisher susceptibility is comparable to Monte Carlo estimated susceptibility across a diverse set of query domains despite its being $70\times$ faster. Exploiting the improved efficiency, we apply Fisher susceptibility to analyze factors affecting the susceptibility of language models. We observe that larger models are as susceptible as smalle