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In this article, we are interested in the life and scientific work of the Belgian mathematician Paul Mansion. The year 2019 marks the centenary of his passing. We bring some new insights into Paul Mansion's work thanks to his scientific correspondence at the Royal Library in Brussels., Comment: in French

This study is about the properties of the sets of objects associated in a structure resulting from multiple-processes involving chance as are materials whose texture is unordered and random. Being a paper scientist the author refers to the sheet of paper which is a stochastic fibrous set whose porous texture can be considered as an archetype for many natural or artificial human structures. The paper properties are correlated with its texture by taking account the effect of chance occurring during its manufacturing process. The theoretical developments, the formalism and the application methods presented in this study have a general significance beyond the only paper material.A specific property of sets of objects randomly unorderly distributed in space is their interfaces orientation distribution. This distribution is usually obtained by the analysis of images sampled in the object sets. The density of orientation probability of the fibers or of the texture interfaces, weighted by their length or by their area, can be interpreted as the radius of curvature of an outline or of a warped surface which characterizes, from a global and statistical point of view, the texture geometry in two or three dimensions. This figure named by the author the "equivalent pore", is with its elliptical shape similar to the one of the mean pore defined by the mean directional chord between the interfaces in the texture. Different methods of "equivalent pore" establishing are analyzed : by conformal map of the fiber network or of the texture interfaces, by images stereometric analysis of texture tomographical cuts, by scattering and diffraction of a laser light beam impacting the fibrous texture or the material surface replica, by hard X-ray absorption and phase contrast at the European Synchrotron Radiation Facilities(ESRF), in Grenoble. The "equivalent pore" concept allows us to study random unordered sets behavior in strength fields while simplifying this analysis. Thus a phenomenon occurring in a plane set, in two dimensions, can be analyzed on its "equivalent pore" linear outline, and a phenomenon which occurs in volume in a three dimensional set can be analyzed on its "equivalent pore" warped surface. This concept has been applied for physical, mechanical, optical and ionic conduction properties of materials like papers, boards, felts, nonwoven textiles, polymer foams, metallic alloys with grain joints, geological grounds, and for the surface mapping of natural relief and of materials with different gloss, worn or roughness levels.The ellipse and the ellipso\"id, as well as multi-modes compositions of it, are the most appropriate figures to represent the "equivalent pore" of materials with a random unordered texture. The fact that a law, which defines the curvature of an elliptic deterministic geometrical configuration, is essential to represent interface orientation allocation of elements whose spatial distribution is probabilistic is a noteworthy fact that makes us wonder. This assertion is corroborated by fluid flow analysis through porous media. The global dissipated energy for fluid flow is distributed along the motion (translation and rotation) and fluid deformation components on the "equivalent pore" whose surface is conformal to the texture interfaces tangential space. The porous media being homogenous and the fluid particles indistinguishable each ones from the others, due to permanent stochastic exchanges from one fluid volume element into another, we conclude that their motion quantification is invariant on each point of the "equivalent pore" surface. This quantification can be represented by a group of elliptical cylinders.The "equivalent pore" and cylinders group surface intersections define the fluid particle probabilistic paths in the porous media. One singular geometrical configuration of the elliptic cylinders group union with the ellipsoidal "equivalent pore" fulfills the minimal energy dissipation requirements in the stress field applied to the fluid. The resulting paths are ellipso\"ido-cylindrical curves carpeting the ellipso\"id by a beam of isoperim\'etric lacets, in close or open loops depending on the possible pairing off the curves in their nodals and isoclinal tangency points. The flow laminarity and unrotationality are globally established in the porous media at the macroscopic scale, for Reynold's number small values, in agreement with the results found moreover. The so defined ellipso\"ido-cylindrical curve is a stationary curve at the average least action meaning, for a punctual mobile or a deformable volume element moving on the surface of the ellipsoid from a nodal spot to the other in an antipodal position. This curve establishes a gauge which characterizes, from a global point of view, the physical space embraced by the fluid during its flow, in dynamical balance conditions compatible with the stress field. The ellipso\"ido-cylindrical curve allows to carpet the ellipso\"id as a function of one cyclic angular variable, which is a new construction for the ellipso\"id. When the set of the objects is isotropic the curve is sphero-cylindrical whose plan mapping permit to decipher the tai-chi figure of the Tao\"ist Buddhism philosophy.This study of random unordered object sets, and more specially of fibrous porous media, allows to establish a structural link between their small scale texture stochastic disorder and the harmonious order that emerges from these sets at a larger scale. The largest chance possible, compatible with the stress field which put a strain on these sets, is the necessary and sufficient variable which allows to best globally adjust their behaviors according to the probabilistic and deterministic laws governing their evolution.The vocabulary used in this study is issued from the common language, most of the time adapted to the material class, it is transposable in other fields of interest. The text is completed by notes and a bibliography which refer to the works done following the presented concepts or in relation to this field of studies., Comment: Derni\`ere version, in French

In 1942, the famous astronomer and physicist Belgian Georges Lemaitre (1894-1966) published in the Bulletin of the class of Sciences of the Royal Academy of Belgium, an article in which he proposes a method that he calls "rational iteration". He rediscovers both the $\Delta^{2}$ Aitken process and the Steffensen's method. We will see how the scientific concerns of Georges Lemaitre in the year 1942 (resolutions of differential equations) have led to this rediscovery., Comment: in French

This article presents a contribution to multi-criteria decision support intended for industrial decision-makers in order to determine the best compromise between design criteria when working on risky or innovative products. In (RENAUD et al. 2008) we used the OWA operator (Ordered Weighted Average), a well-known multi-criteria analysis technique introduced by (YAGER 1988). The interest of this aggregation method is, beyond its ease of use, its ability to evaluate a product according to a single scale. When using the OWA method, the choice of criterion weights and their values remains an important and delicate operation. Indeed, the weights are not fixed by criterion but according to a level of utility (FISHBURN 1967). The weights can, in addition, be determined using different methods. A traditional approach consists in estimating the weights from an a priori selection of the most representative samples by an expert. We propose a new approach based on applied D-Optimality to determine the best sample. The results of the two approaches are compared. Indeed, in some multi-criteria decision problems, it is difficult to choose the method that best describes the behavior of the decision maker. As said above, the first part of this paper presents an original method based on D-optimality to determine the most representative set of samples to determine the decision parameters. This method has been applied and validated in an OWA approach. It has been shown that the accuracy and reliability of the method have been improved. Since the OWA application has been improved, the other goal of this paper is to verify whether the real decision maker has an OWA-based behavior or not. To achieve this, the D-optimality approach is applied to the MAUT (Multi-Attribute Utility Theory) approach to find the best set of samples. The results of the two methods are compared. Both approaches show that, while OWA better simulates the decision maker's behavior, there is still a gap between its scores and that of OWA. The question here is how to improve the accuracy of the score estimated by OWA compared to those given by the expert. Subsequently, a hybrid approach is tested, such as a linear combination of the MAUT and OWA approaches. The results obtained with this combination were found to be more accurate than those of OWA. However, we also tested the CHOQUET discrete integral approach. In other words, it is possible to find a model capable of better describing the decision maker's behavior., Comment: in French language

Conventionally, surface tension is expressed as a force per unit length or as an energy per unit area.In this paper, we propose a thought experiment which consists of replacing the surface tension by an equivalent force gradient following fluid mechanics principles. Such a system of equivalent forces allows to analyze the effects of tensioactivity in terms of force per unit area or in terms of energy per unit volume.This theoretical tool proposes an alternative vision of tensioactivity forces at the interfaces and allows to rewrite the wellknown capillarity equations by calculating forces equilibrium at steady state. The new equations will be applied the case of known phenomena known phenomena such as meniscus, capillary tube, wilhelmy blade and equilibrium of drops and semi-drops.The paper will be concluded by extending our thought experience with the formulation of some hypotheses that would make it possible to interpret such equivalent stress gradients., Comment: in French language

A holomorphic pre-foliation $\mathscr{F}=\mathcal{C}\boxtimes\mathcal{F}$ on $\mathbb{P}^{2}_{\mathbb{C}}$ is the data of a reduced complex projective curve $\mathcal{C}$ of $\mathbb{P}^{2}_{\mathbb{C}}$ and a holomorphic foliation $\mathcal{F}$ on $\mathbb{P}^{2}_{\mathbb{C}}$. When the foliation $\mathcal{F}$ is convex and the curve $\mathcal{C}$ is invariant by $\mathcal{F}$, we speak of convex pre-foliation. In a previous paper, we showed that if a foliation $\mathcal{F}$ on $\mathbb{P}^{2}_{\mathbb{C}}$ is reduced convex or homogeneous convex and if $\mathcal{C}$ is an invariant line of $\mathcal{F}$, then the dual web of the convex pre-foliation $\mathcal{C}\boxtimes\mathcal{F}$ is flat. In this paper, we propose to extend this result to the case of a curve $\mathcal{C}$ consisting of several invariant lines., Comment: 7 pages, in French language

Patents and scientific papers provide an essential source for measuring science and technology output, to be used as a basis for the most varied scientometric analyzes. Authors' and inventors' names are the key identifiers to carry out these analyses, which however, run up against the issue of disambiguation. By extension identifying inventors who are also academic authors is a non-trivial challenge. We propose a method using the International Patent Classification (IPC) and the IPCCAT API to assess the degree of similarity of patents and papers abstracts of a given inventor, in order to match both types of documents. The method is developed and manually qualified based on three corpora of patents extracted from the international EPO database Espacenet. Among a set of 4679 patents and 7720 inventors, we obtain 2501 authors. The proposed algorithm solves the general problem of disambiguation with an error rate lower than 5%., Comment: in French language

Growing awareness of the environmental impact of digital technologies has led to several isolated initiatives to promote sustainable practices. However, despite these efforts, the environmental footprint of generative AI, particularly in terms of greenhouse gas emissions and water consumption, remains considerable. This contribution first presents the components of this environmental footprint, highlighting the massive CO2 emissions and water consumption associated with training large language models, thus underlining the need to rethink learning and inference methods. The paper also explores the factors and characteristics of models that have an influence on their environmental footprint and demonstrates the existence of solutions to reduce it, such as using more efficient processors or optimising the energy performance of data centres. The potentially harmful effects of AI on the planet and its ecosystem have made environmental protection one of the founding principles of AI ethics at international and European levels. However, this recognition has not yet translated into concrete measures to address it.To address this issue, our contribution puts forward twelve pragmatic recommendations for public action to promote sustainable generative AI, in particular by building a long-term strategy to achieve carbon neutrality for AI models, encouraging international cooperation to set common standards, supporting scientific research and developing appropriate legal and regulatory frameworks.This paper seeks to inform the members of the Interministerial Committee on Generative AI about the environmental challenges of this technology by providing a brief review of the scientific literature on the subject and proposing concrete recommendations of public policy actions to reconcile technological innovation with the need to protect our environment., Comment: in French language

Ce texte, \'ecrit pour la Gazette de la Soci\'et\'e math\'ematique de France, \'evoque les fonctions de type positif et leur histoire avant 1950 ; on y pr\'esente notamment des extraits de lettres \'ecrites par Roger Godement, qui leur consacra sa th\`ese en 1946. This is an expository paper on the early history of positive-definite functions, written for the "Gazette de la Soci\'et\'e Math\'ematique de France". It contains pictures of letters written by Roger Godement, during and after the preparation of his 1946 thesis about positive-definite functions on groups., Comment: 16 pages, in French, 9 figures with extracts of letters by Godement; to appear in the "Gazette de la Soc. Math. France"

As large language models (LLMs) continue to make significant strides, their better integration into agent-based simulations offers a transformational potential for understanding complex social systems. However, such integration is not trivial and poses numerous challenges. Based on this observation, in this paper, we explore architectures and methods to systematically develop LLM-augmented social simulations and discuss potential research directions in this field. We conclude that integrating LLMs with agent-based simulations offers a powerful toolset for researchers and scientists, allowing for more nuanced, realistic, and comprehensive models of complex systems and human behaviours., Comment: 8 pages, in French language, 0 figures, Journ\'ees Francophones de la Mod\'elisation et de la Simulation (JFMS 2024)

In algebraic topology, we usually represent surfaces by mean of cellular complexes. This representation is intrinsic, but requires to identify some points through an equivalence relation. On the other hand, embedding a surface in a Euclidean space is not intrinsic but does not require to identify points. In the present paper, we are interested in the M\"obius strip, the torus, and the real projective plane. More precisely, we construct explicit homeomorphisms, as well as their inverses, from cellular complexes to surfaces of 3-dimensional (for the M\"obius strip and the torus) and 4-dimensional (for the projective plane) Euclidean spaces. All the embeddings were already known, but we are not aware if explicit formulas for their inverses exist., Comment: in French language

This present paper provides the absolutely necessary corrections to the previous work entitled {\it A polynomial Time Algorithm to Solve The Max-atom Problem} (arXiv:2106.08854v1). The max-atom-problem (MAP) deals with system of scalar inequalities (called atoms or max-atom) of the form: $x \leq a + \max(y,z)$. Where $a$ is a real number and $x,y$ and $z$ belong to the set of the variables of the whole MAP. A max-atom is said to be positive if its scalar $a$ is $\geq 0$ and stricly negative if its scalar $a <0$. A MAP will be said to be positive if all atoms are positive. In the case of non positive MAP we present a saturation principle for system of vectorial inequalities of the form $x \leq A x + b$ in the so-called $(\max,+)$-algebra assuming some properties on the matrix $A$. Then, we apply such principle to explore all non-trivial solutions (ie $\neq -\infty$). We deduce a strongly polynomial method to express all solutions of a non positive MAP. In the case a positive MAP which has always the vector $x^{1}=(0)$ as trivial solution we show that looking for all solutions requires the enumeration of all elementary circuits in a graph associated with the MAP. However, we propose a strongly polynomial method wich provides some non trivial solutions., Comment: in French language

This paper studies changes in articulatory configurations across genders and periods using an inversion from acoustic to articulatory parameters. From a diachronic corpus based on French media archives spanning 60 years from 1955 to 2015, automatic transcription and forced alignment allowed extracting the central frame of each vowel. More than one million frames were obtained from over a thousand speakers across gender and age categories. Their formants were used from these vocalic frames to fit the parameters of Maeda's articulatory model. Evaluations of the quality of these processes are provided. We focus here on two parameters of Maeda's model linked to total vocal tract length: the relative position of the larynx (higher for females) and the lips protrusion (more protruded for males). Implications for voice quality across genders are discussed. The effect across periods seems gender independent; thus, the assertion that females lowered their pitch with time is not supported., Comment: accepted to InterSpeech 2024, Kos Island, Greece keywords : acoustic to articulatory inversion, diachrony, gender, French, media

This paper presents a graph cascade for sentence segmentation of XML documents. Our proposal offers sentences inside sentences for cases introduced by quotation marks and hyphens, and also pays particular attention to situations involving incises introduced by parentheses and lists introduced by colons. We present how the tool works and compare the results obtained with those available in 2019 on the same dataset, together with an evaluation of the system's performance on a test corpus, Comment: in French language

Energy consumption remains the main limiting factors in many promising IoT applications. In particular, micro-controllers consume far too much power. In order to overcome this problem, new circuit designs have been proposed and the use of spiking neurons and analog computing has emerged as it allows a very significant consumption reduction. However, working in the analog domain brings difficulty to handle the sequential processing of incoming signals as is needed in many use cases.In this paper, we propose to use a bio-inspired phenomenon called Interacting Synapses to produce a time filter. We propose a model of synapses that makes the neuron fire for a specific range of delays between two incoming spikes, but not react when this Inter-Spike Timing is not in that range. We study the parameters of the model to understand how to adapt the Inter-Spike Timing. The originality of the paper is to propose a new way, in the analog domain, to deal with temporal sequences., Comment: in French language

The graph partitioning problem (GPP) is among the most challenging models in optimization. Because of its NP-hardness, the researchers directed their interest towards approximate methods such as the genetic algorithms (GA). The edge-based GA has shown promising results when solving GPP. However, for big dense instances, the size of the encoding representation becomes too huge and affects GA's efficiency. In this paper, we investigate the impact of modifying the size of the chromosomes on the edge based GA by reducing the GPP edge set. We study the GA performance with different levels of reductions, and we report the obtained results., Comment: This is a slightly modified exended version of a paper (in French) accepted in COSI'17 as a poster. The title of the originel paper is "Ali Chaouche and Menouar Boulif. Codage binaire avec seuil pour la resolution du probleme de partitionnement de graphes avec des algorithmes genetiques"

This paper presents the development of a lexicon centered on emerging concepts, focusing on non-technological innovation. It introduces a four-step methodology that combines human expertise, statistical analysis, and machine learning techniques to establish a model that can be generalized across multiple domains. This process includes the creation of a thematic corpus, the development of a Gold Standard Lexicon, annotation and preparation of a training corpus, and finally, the implementation of learning models to identify new terms. The results demonstrate the robustness and relevance of our approach, highlighting its adaptability to various contexts and its contribution to lexical research. The developed methodology promises applicability in conceptual fields., Comment: in French language. JADT 2024

The future of e-Learning is on the way to be constructed within ICT standardization international instances. The sub-committee 36 of ISO, which is responsible for standardizing educational technologies, is certainly the most prominent of all. The authors of this paper, who are official delegates of the Agency of French Speaking Universities (AUF) with this structure, highlight the strategic importance of active monitoring of e-Learning standards for preserving cultural diversity, linguistic and equal access to education for all., Comment: in French language, Distances et savoirs, 2008, HS

Let $\overline{\mathbb{Q}}$ be an algebraic closure of $\mathbb{Q}$ and $\mathbb{Q}^{tr}$ be the subfield of $\overline{\mathbb{Q}}$ obtained by taking the union of all totally real number fields. For any prime $p\geq 3$, let $F_p/\mathbb{Q}$ be the Fermat curve of equation $x^p+y^p+z^p=0$. In 1996, Pop has shown that the field $\mathbb{Q}^{tr}$ is large. In particular, the set $F_p(\mathbb{Q}^{tr})$ of the points of $F_p$ rational over $\mathbb{Q}^{tr}$ is infinite. How to explicit non-trivial points $(xyz\neq 0$) in $F_p(\mathbb{Q}^{tr})$ ? If one has $p\geq 5$, it seems that the only points already known in $F_p(\mathbb{Q}^{tr})$ are those of $F_p(\mathbb{Q})$ and they are trivial. In this paper, we investigate this question in case $p=5$. There are no totally real fields whose degree over $\mathbb{Q}$ is at most $5$ over which $F_5$ has non-trivial points. We propose here to explicit infinitely many points of $F_5$ rational over totally real fields of degree $6$ over $\mathbb{Q}$., Comment: in French language

This paper presents the proof-of-concept of the first automatic voice assistant ever built in Wolof language, the main vehicular language spoken in Senegal. This voicebot is the result of a collaborative research project between Orange Innovation in France, Orange Senegal (aka Sonatel) and ADNCorp, a small IT company based in Dakar, Senegal. The purpose of the voicebot is to provide information to Orange customers about the Sargal loyalty program of Orange Senegal by using the most natural mean to communicate: speech. The voicebot receives in input the customer's oral request that is then processed by a SLU system to reply to the customer's request using audio recordings. The first results of this proof-of-concept are encouraging as we achieved 22\% of WER for the ASR task and 78\% of F1-score on the NLU task., Comment: in French language

This research documents the results of the piloting of an innovative technology with a limited-water fortification parboiling method developed by the University of Arkansas with eleven women rice parboiling cooperatives in Burkina Faso. The technology is easily adaptable to the parboiling method currently used in Burkina Faso (with some modifications), reduces water use and cost of fortificants contributing to food and nutritional security—particularly for women and children—and promotes economic empowerment of women in Burkina Faso. The paper also synthesizes two research papers on consumer preferences and willingness to pay for fortified rice products in Burkina Faso., The results suggest that it is technically feasible to produce fortified rice using the limited-water method and brown rice as a feedstock, particularly for iron and zinc, for which the concentration levels were close to the recommended dietary allowance (RDA). From the sensory analysis, although there is nothing particularly wrong with fortified rice, urban and rural consumers preferred conventional and modified parboiled rice; and of all three rice products, consumers were more likely to buy the two rice alternatives rather than fortified rice., The results from the experimental auctions show that most consumers were willing to pay the same price for fortified rice as for the conventional parboiled rice currently available on the market. Results showed that creating awareness on the benefits of fortified rice had a positive impact on consumers’ willingness to pay for it, and this was seen across all income levels. These results highlight the importance of designing an appropriate marketing campaign/awareness-raising to promote the nutritional benefits of fortified rice to increase the consumers’ willingness to pay for it., This study is unique in that, to our knowledge, fortified rice is not available in Burkina Faso, and therefore there is no information about its technical and market feasibility. The results can be used by the government and private and public sector actors to develop strategies for the adoption of fortified rice as another potentially relevant tool to fight malnutrition in Burkina Faso.

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The objective of this paper is to study the Hausdorff measure, a fundamental concept in fractal geometry. We begin by defining the Hausdorff outer measure, which allows us to assign a measure to any subset of a metric space. We then present Caratheodory's theorem, which characterizes the outer measure in terms of coverings by open sets. We also study the construction of the Hausdorff measure from the outer measure. Next, we introduce the Hausdorff measure proper, which is an extension of the outer measure. We give a formal definition and discuss its properties, such as monotonicity and translation invariance. We also address the notion of Hausdorff dimension, which is a generalization of Euclidean dimension to non-regular sets. Finally, we present an application of the Hausdorff measure to the Cantor ternary set, which is a classic example of a fractal set. We calculate the Hausdorff dimension of this set and show how the Hausdorff measure can be used to quantify the geometric complexity of this object. Overall, this paper provides a comprehensive introduction to the Hausdorff measure, which is an essential concept for understanding fractal geometry and its applications in many scientific fields., Comment: in French language

Recent advances in material technology and in micro- and nano-electronics have profoundly changed the design of intracranial electrophysiology electrodes. It is now possible to manufacture electrodes that record cortical activity at a spatial resolution that was previously unthinkable. This high spatial resolution enables recording of the functional structures of the brain, and differentiation of the activity of the different types of neurons composing them. In this paper, we present a review of the different types of electrodes now available, and then suggest one of the first applications for such high resolution electrodes, namely a means to better characterise the mechanisms that generate focal seizures in epileptics. Finally, we reflect more broadly on prospects for their future use., Comment: Published in the Fyssen Annals 2021 in French and English. Article in French: pages 1-7. Article in English: pages 7-13

This paper explores two critical infrastructure proposals as alternatives to the current state of the Internet protocols: IPFS (Interplanetary File System) and Scuttlebutt, highlighting the political a priori and debates of these technical enterprises. To do so, I propose to analyze the discourses of the developers of these two systems in the mode of a critical discourse analysis.This article highlights a particular form of criticism of Internet regimes: infrastructural criticism, and highlights its variety through a comparative study. Through these two case studies, we will see how different alternatives to the current spatio-temporal implementations of the Internet allow us to identify the agency dimensions of these acts of hijacking and substitution, characterizing two quite different approaches to decentralized protocols, yet linked by a technical similarity., Comment: in French language

As part of the Digital Working Group (GTnum) #Scol_IA "Renewal of digital practices and creative uses of digital and AI" we are pleased to present the white paper "Teaching and learning in the era of Artificial Intelligence, Acculturation, integration and creative uses of AI in education". The white paper edited by Margarida Romero, Laurent Heiser and Alexandre Lepage aims to provide the various educational actors with a diversified perspective both on the issues of acculturation and training in AI and on the resources and feedback from the various research teams and organisations. of scientific culture in the French-speaking countries. A multidisciplinary approach makes it possible to consider the perspectives of researchers in computer science as well as those of education and training sciences, information and communication sciences and the expertise of teaching professionals. and scientific mediation., Comment: in French language

For specific classes of smooth, projective varieties $X$ over a field $k$, we compare two cycle maps on the torsion subgroup $CH^2(X)_{\text{tors} }$ of the second Chow group. The first one goes back to work of S. Bloch (1981), the second one is Jannsen's cycle map into continuous $\ell$-adic cohomology, whose injectivity properties have attracted attention in two recent papers. On the one hand, the comparison gives sufficient hypotheses to guarantee injectivity of Jannsen's cycle map sending $CH^2(X)$ to $H^4_{cont}(X, Z_{\ell}(2))$ on $\ell$-primary torsion. On the other hand, using counterexamples to injectivity of the first map due to Sansuc and the first author (1983), we give examples of smooth, projective, geometrically rational surfaces over a rational function field in one variable over a totally imaginary number field for which Jannsen's map for $\ell=2$ is not injective on $2$-torsion. This answers questions raised in a recent paper., Comment: 25 pages, in French; added one missing hypothesis in condition (H4) in section 3

This text is a commentary on the paper "On some ideals of differentiable functions" of Ren{\'e} Thom which appeared in Volume II of his "Oeuvres Math{\'e}matiques" published by the Soci{\'e}t{\'e} math{\'e}matique de France, s{\'e}rie "Documents Math{\'e}matiques", in 2019., Comment: in French language

Let $G=(V,A)$ be a digraph. For $X\subseteq V$, the subdigraph of $G$ induced by $X$ is denoted by $G[X]$. A subset $I$ of $V$ is an interval of $G$ if for every $a,b \in I$ and $x \in V \setminus I$, $(x,a) \in A$ if and only if $(x,b) \in A$, and similarly for $(a,x)$ and $(b,x)$. The trivial intervals of $G$ are $\varnothing$, $V$ and $\lbrace x\rbrace$, where $x\in V$. The digraph $G$ is indecomposable if $| V(G)|\geqslant 3$ and all its intervals are trivial. Given an indecomposable digraph $G$, a vertex $x$ of $G$ is critical, if the induced subdigraph $G[V(G) \setminus \{x\}]$ is decomposable. The digraph $G$ is said to be (-1)-critical if it admits a single non-critical vertex. A poset (or a strict partial order) is a transitive digraph. In this paper, We characterize the (-1)-critical posets., Comment: 15 pages, in French language, 6 figures

There is growing consensus among policymakers, institutions and movements that GDP is not fit for purpose as the pre-eminent economic metric. Alternatives are urgently needed to facilitate the transition to a new economic model that supports a radically more equal, kinder, greener and feminist world in the present, while offering redress for historical damage and inequalities., However, despite growing experimentation, most efforts are insufficiently bold and remain mostly on paper, with only a few notable but relatively small-scale and still-developing exceptions., To dismantle GDP, different social movements will need to coalesce around key metrics that prioritise far greater equality, and align with feminist and decolonial values while challenging the systems of power and narratives that are holding GDP in its dominant place. Only in this way are alternatives likely to deliver the economic transformation needed to put people and planet first., Les responsables politiques, les institutions et divers mouvements s’accordent de plus à plus à dire que le produit intérieur brut (PIB), en tant que principal indicateur de la santé économique, n’est pas un outil satisfaisant. Il est urgent de trouver des alternatives pour la transition vers un nouveau modèle économique favorisant un monde radicalement plus égalitaire, bienveillant, vert et féministe et proposant des mesures de réparation des dommages causés par le passé et des inégalités qui en découlent. Toutefois, malgré de nombreuses expériences, la plupart de celles-ci manquent d’ambition et ne sont pas appliquées, à l’exception de rares propositions en cours de développement, notables mais d’envergure relativement restreinte. Pour détrôner le PIB, divers mouvements sociaux devront travailler à la création d’indicateurs clés qui privilégieront l’égalité, intégreront les valeurs féministes et décoloniales et remettront en question les systèmes de pouvoir et les discours qui perpétuent l’utilisation du PIB. C’est la seule manière pour ces alternatives d’entraîner la transformation économique indispensable pour protéger la planète et les êtres humains avant tout.

This paper reviews and synthesizes three research papers that look at gender-responsive budgeting in Ethiopia, Ghana, and Tanzania, with the aim of drawing out common themes and lessons learned on what it takes to ensure well-functioning gender-responsive budgeting (GRB) and how it can benefit women small-scale farmers. While Ethiopia, Ghana, and Tanzania are not countries that systematically and efficiently practice GRB, the in-depth look at the challenges and successes of GRB in each of these countries provides some helpful insights. After a brief background section summarizing the history of GRB in each country, this paper outlines the lessons learned in five categories: Setting up government practices, systems, and structures for gender-responsive budgeting; Designing a more gender-responsive budgeting process; Engaging citizens in the budgeting process; Envisioning gender-responsive budgeting outcomes; and Identifying best practices in GRB advocacy by NGOs.

Obtaining a rigorous justification of the kinetic theory of gases from Newton's second law of dynamics for a large number of identical spheres interacting by elastic binary collisions, is a problem formulated by Hilbert in 1900 (Hilbert's 6th problem). In 1975, Lanford demonstrated the validity of the Boltzmann equation over a very short time interval, of the order of a fraction of the average time between two successive collisions experienced by the same particle. This result of Lanford can be interpreted as a kind of law of large numbers as the number of particles tends to infinity. This point of view raises several questions. First, the core of the argument used by Boltzmann to arrive at the equation bearing his name is the assumption that two particles about to collide are statistically almost independent. This suggests to examine the validity of this hypothesis by studying the dynamics of correlations between particles. On the other hand, the interpretation of the Boltzmann equation as a law of large numbers leads to study precisely the fluctuations of the phase space empirical measure of the particle system about its mean (whose evolution is described by the Boltzmann equation). A series of recent papers by T. Bodineau, I. Gallagher, L. Saint-Raymond and S. Simonella answers these various questions and allows going beyond the Boltzmann equation in the understanding of the kinetic theory of gases., Comment: 53 pages, in French language, 3 figures. Bourbaki seminar, November 19th 2022

We prove constructively a Nullstellensatz giving an equivalence between the existence of a certain kind of algebraic identity on one hand, and the impossibility of finding an increasing sequence of irreducible varieties obeying certain constraints on the other hand. The ususal Nullstellensatz corresponds to the case of varieties that are reduced to a point. We settle also a similar formal Nullstellensatz related to increasing sequences of primes. An important particular case is given by the notion of pseudo regular sequence. This allows a new characterisation of the Krull dimension of a ring. This characterisation via pseudo regular sequences is elementary and constructive. Our method uses dynamical algebraic structures which were introduced in previous papers., Comment: in French language

Expectation-Maximization (EM) algorithm is a widely used iterative algorithm for computing maximum likelihood estimate when dealing with Gaussian Mixture Model (GMM). When the sample size is smaller than the data dimension, this could lead to a singular or poorly conditioned covariance matrix and, thus, to performance reduction. This paper presents a regularized version of the EM algorithm that efficiently uses prior knowledge to cope with a small sample size. This method aims to maximize a penalized GMM likelihood where regularized estimation may ensure positive definiteness of covariance matrix updates by shrinking the estimators towards some structured target covariance matrices. Finally, experiments on real data highlight the good performance of the proposed algorithm for clustering purposes, Comment: in French language

Linear and Quadratic Discriminant Analysis (LDA and QDA) are well-known classical methods but can heavily suffer from non-Gaussian distributions and/or contaminated datasets, mainly because of the underlying Gaussian assumption that is not robust. This paper studies the robustness to scale changes in the data of a new discriminant analysis technique where each data point is drawn by its own arbitrary Elliptically Symmetrical (ES) distribution and its own arbitrary scale parameter. Such a model allows for possibly very heterogeneous, independent but non-identically distributed samples. The new decision rule derived is simple, fast, and robust to scale changes in the data compared to other state-of-the-art method, Comment: in French language

Many matrices associated with fast transforms posess a certain low-rank property characterized by the existence of several block partitionings of the matrix, where each block is of low rank. Provided that these partitionings are known, there exist algorithms, called butterfly factorization algorithms, that approximate the matrix into a product of sparse factors, thus enabling a rapid evaluation of the associated linear operator. This paper proposes a new method to identify algebraically these block partitionings for a matrix admitting a butterfly factorization, without any analytical assumption on its entries., Comment: in French language. XXIX{\`e}me Colloque Francophone de Traitement du Signal et des Images, Aug 2023, Grenoble, France

In this article, we present {\it GenderedNews} (\url{https://gendered-news.imag.fr}), an online dashboard which gives weekly measures of gender imbalance in French online press. We use Natural Language Processing (NLP) methods to quantify gender inequalities in the media, in the wake of global projects like the Global Media Monitoring Project. Such projects are instrumental in highlighting gender imbalance in the media and its very slow evolution. However, their generalisation is limited by their sampling and cost in terms of time, data and staff. Automation allows us to offer complementary measures to quantify inequalities in gender representation. We understand representation as the presence and distribution of men and women mentioned and quoted in the news -- as opposed to representation as stereotypification. In this paper, we first review different means adopted by previous studies on gender inequality in the media : qualitative content analysis, quantitative content analysis and computational methods. We then detail the methods adopted by {\it GenderedNews} and the two metrics implemented: the masculinity rate of mentions and the proportion of men quoted in online news. We describe the data collected daily (seven main titles of French online news media) and the methodology behind our metrics, as well as a few visualisations. We finally propose to illustrate possible analysis of our data by conducting an in-depth observation of a sample of two months of our database., Comment: Paper in French

The \S 2 of our work "Sous-groupe de Brauer invariant et obstruction de descente it\'er\'ee" uses a statement about the degree two K\"unneth formula proved by Skorobogatov and Zarhin in their paper "The Brauer group and the Brauer-Manin set of products of varieties". Recently they find that this statement is not correct (see their Corrigendum). We correct \S 2 of our paper. The rest of our paper is still correct., Comment: In French

This is a survey article, presenting few of the mathematical achievements of J.-P. Demailly. We discuss a few aspects of his approach for Fujita conjecture, and results around the K\"ahler cone of a compact K\"ahler manifold. The article will appear in a special issue of "Gazette des Math\'ematiciens"., Comment: En fran\c{c}ais dans le texte (written in French)

We study various formulations of the boundary conditions for the Euler equations of gas dynamics from a mathematical and numerical point of view. In the case of one space dimension, we recall the classical results, based on an analysis of the linearized problem. Then we present a more recent formulation of the problem, which allows for nonlinear effects at the boundary of the study domain. This formulation fits naturally into a finite volume discretization, and we present a significant one-dimensional test case., Comment: in French language

This article focuses on the articulatory characteristics of epistemic gestures (i.e., gestures used to express certainty or uncertainty) in co-speech gestures (CSG) in French and in French Sign Language (LSF). It presents a new methodology for analysis, which relies on the complementary use of manual annotation (using Typannot) and semi-automatic annotation (using AlphaPose) to highlight the kinesiological characteristics of these epistemic gestures. The presented methodology allows to analyze the flexion/extension movements of the head in epistemic contexts. The results of this analysis show that in CSG and LSF: (1) head nods passing through the neutral position (i.e., head straight with no flexion/extension) and high movement speed are markers of certainty; and (2) holding the head position away from the neutral position and low movement speed indicate uncertainty. This study is conducted within the framework of the ANR LexiKHuM project, which develops kinesthetic communication solutions for human-machine interaction., Comment: in French language, Anvur E062307, Scholar

We define a class of skeletons on Berkovich analytic spaces, which we call "accessible", which contains the standard skeleton of the n-dimensional torus for every n and is preserved by G-glueing, by taking the inverse image along a morphism of relative dimension zero, and by taking the direct image along a morphism whose restriction to the involved skeleton is topologically proper., Comment: in French language, 66 pages

We show that, in the unit tangent bundle of a hyperbolic orbisphere with cone points of order 3, 3, 4, the lift of the shortest periodic geodesic is homeomorphic to the complement of the figure-eight knot in the 3-sphere. The proof eventually relies on the computation of some linking numbers., Comment: These expository notes present a picturial and dynamical proof of a theorem for which we claim no novelty. 14 pages, in French language, 10 figures

The ranking of possible alternatives during the design or operation of an industrial process leads to the definition of a solution representing the best compromise between several contradictory objectives. The choice of solution is a decision that can be modeled using knowledge of the corresponding preferences. The decision and preference model used is that of flow balances. Munster cheese is used as an example. These are highly distinctive cheeses that are not suitable for uninformed consumers. If the decision-maker wishes to widen his consumer panel, he must modify the production line settings. In the event of a change in preferences due to an external influence, the decision-maker must adapt, but not too abruptly, to avoid both production line oscillations and consumer annoyance. To solve this problem, we propose a new technique: dynamic flow balances. This makes it possible to forecast production trends. Prospects are also proposed, such as the creation of a multi-criteria predictive control., Comment: in French language

Climate change will result in more frequent, more intense and longer-lasting heat waves by 2050. As part of its Climate Plan and its resilience strategy, the City of Paris is deploying, through its Oasis program, a network of urban cool islands to mitigate the urban heat island phenomena: schoolyards are renovated in order to reduce the heat stress of users. We establish a methodology aiming to quantify the microclimatic impact of the transformation. Mobile measurements are carried out within a case courtyard under hot conditions and coupled with fixed weather station data to evaluate heat stress using UTCI. The heat stress mapping thus obtained allows a first microclimatic diagnosis of the schoolyard., Comment: in French language, 34e Colloque Annuel de l'Association Internationale de Climatologie, Jul 2021, Casablanca, Maroc

To enhance the understanding of air quality within underground railway stations (URS), a methodology has been developed to establish a baseline profile of particle concentrations (PM10 and PM2.5). This approach incorporates an extensive data cleaning process based on the identification of URS operation periods, physically inconsistent or mathematically aberrant data, and comparing the profile of each day to an average profile. The versatility of this methodology allows its application to different particle classes within various URS. The results obtained from the three studied URS indicate the possibility of obtaining reliable daily typical profiles even over short measurement periods (up to one or two weeks)., Comment: in French language, Congr{\`e}s Fran\c{c}ais sur les A{\'e}rosols 2024, ASFERA, Mar 2024, Paris, France

Corporate social responsibility encourages companies to integrate social and environmental concerns into their activities and their relations with stakeholders. It encompasses all actions aimed at the social good, above and beyond corporate interests and legal requirements. Various international organizations, authors and researchers have explored the notion of CSR and proposed a range of definitions reflecting their perspectives on the concept. In Morocco, although Moroccan companies are not overwhelmingly embracing CSR, several factors are encouraging them to integrate the CSR approach not only into their discourse, but also into their strategies. The CGEM is actively involved in promoting CSR within Moroccan companies, awarding the "CGEM Label for CSR" to companies that meet the criteria set out in the CSR Charter. The process of labeling Moroccan companies is in full expansion. The graphs presented in this article are broken down according to several criteria, such as company size, sector of activity and listing on the Casablanca Stock Exchange, in order to provide an overview of CSR-labeled companies in Morocco. The approach adopted for this article is a qualitative one aimed at presenting, firstly, the different definitions of the CSR concept and its evolution over time. In this way, the study focuses on the Moroccan context to dissect and analyze the state of progress of CSR integration in Morocco and the various efforts made by the CGEM to implement it. According to the data, 124 Moroccan companies have been awarded the CSR label. For a label in existence since 2006, this figure reflects a certain reluctance on the part of Moroccan companies to fully implement the CSR approach in their strategies. Nevertheless, Morocco is in a transitional phase, marked by the gradual adoption of various socially responsible practices., Comment: in French language

The EU Artificial Intelligence Act (AI Act) came into force in the European Union (EU) on 1 August 2024. It is a key piece of legislation both for the citizens at the heart of AI technologies and for the industry active in the internal market. The AI Act imposes progressive compliance on organisations - both private and public - involved in the global value chain of AI systems and models marketed and used in the EU. While the Act is unprecedented on an international scale in terms of its horizontal and binding regulatory scope, its global appeal in support of trustworthy AI is one of its major challenges., Comment: in French language

This research, focused on small work groups, proposes to examine the role of the leader in the appropriation of collaborative information systems. It is based on a three-year action research conducted during the implementation of the Microsoft Teams collaborative platform at a university. The aim is to understand how groups of students organize themselves to carry out complex projects over a long period of time and with varying distance constraints. Differences in the appropriation of the new tool appeared depending on whether the mode of work was cooperative or collaborative. To understand these different dynamics, we mobilize Vygotsky's activity theories (TA), more precisely Engestr{\"o}m's 2nd generation TA model (2000). The results reveal the role of leaders through the cooperation versus collaboration tension. In teams, a leader emerges who organizes cooperation but slows down the appropriation of collaborative features of the new information system., Comment: in French language. 28{\`e}me conf{\'e}rence de l'AIM, Association information et management, May 2023, DIJON, France

In an increasingly dynamic and modern market, the recurrence of unexpected events necessitates proactive responses from information system (IS) stakeholders. Each IS actor strives to legitimize its actions and communicate its strategy. This study delves into the realm of IS legitimation, focusing on the communication of two key stakeholders: IS consultancy companies and international organizations, particularly in the context of unexpected events. To achieve this objective, we examined a diverse array of publications released by both actors. Employing a topic modeling methodology, we analyzed these documents to extract valuable insights regarding their methods of legitimation. Through this research, we aim to contribute to the legitimation discourse literature by offering an exploration of two key IS stakeholders responding to the challenges posed by unexpected events., Comment: Includes translation of the abstract in French language. 29e Conf{\'e}rence de l'Association Information et Management 27-29 mai 2024 {\`a} Montpellier - La Grande-Motte, May 2024, Montpellier, France