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Locating small-scale heterogeneities with DAS
No full textInternational audienceDistributed Acoustic Sensing (DAS), a photonic technology that converts a fibre-optic cable into a long (tens of kilometres) high-linear-density (every few metres) array of seismo-acoustic sensors, can provide high-density, high-resolution strain measurements along the entire cable. The potential of such a distributed measurement has gained increasing attention in the seismology community for a wide range of applications. It has been shown that DAS has a subwavelength sensitivity to heterogeneities near the fibre-optic cable. This sensitivity is linked to the fact that the DAS measures deformation, as opposed to the displacements that seismometers measure. However, this sensitivity can create difficulties for many DAS applications, such as source location or distant imaging. Regardless, it can be advantageous in obtaining information about the subsurface near the cable. Here we present a method to locate small hetero-geneities near the fibre-optic cable by inverting an indicator of the small-scale heterogeneities: the homogenised first-order corrector. We show that this first-order corrector can be used to locate heterogeneities near the fibre-optic cable at the gauge length precision, independent of the wavelength
La storia non è fatta di analogie, ma ci permette di analizzarle. Imperi e democrazie alle soglie di una nuova era.: Imperi e democrazie alle soglie di una nuova era.
No full textIm Kontext der aktuellen Spannungen erscheint der Vergleich der mehr oder weniger jungen Entwicklung der internationalen Beziehungen mit der Zeit vor dem Zweiten Weltkrieg unerlässlich. In diesem Text diskutiere ich zwei besonders aufschlussreiche Punkte und zeige Gemeinsamkeiten und Unterschiede zwischen den beiden Zeiträumen auf.Es kann eine Parallele zwischen dem Interview zwischen Wolodymyr Selenskyj und Donald Trump und dem zwischen dem tschechoslowakischen Präsidenten Emil Hácha und Adolf Hitler gezogen werden, wobei daran erinnert wird, dass Donald Trump im Gegensatz zu Hitler gegen die Tschechoslowakei kein direkter Aggressor der Ukraine ist, sondern sich wie der Sprecher des Aggressorstaates Russland verhält. Zweitens interessiert mich die Fragmentierung und Verrohung politischer Landschaften. Ich biete einen Einblick, unabhängig von den Grenzen, zwischen der aktuellen Situation Frankreichs und einigen Elementen, die seine politische Landschaft in der Zwischenkriegszeit charakterisieren.In the context of current tensions, comparing the more or less recent developments in international relations with the period preceding World War II seems essential. In this article, I raise two particularly revealing points, identifying similarities and differences between the two periods.A parallel can be drawn between the meeting between Volodymyr Zelensky and Donald Trump and the one between Czechoslovak President Emil Hácha and Adolf Hitler, while recalling that, unlike Hitler in his dealings with Czechoslovakia, Donald Trump is not a direct aggressor against Ukraine but has acted as the spokesperson for the aggressor state, Russia. Second, I focus on the fragmentation and brutalization of political landscapes. I offer insight, whatever its limitations, into the recent situation in France and some elements characterizing its political landscape in the interwar period.En el contexto de las tensiones actuales, parece esencial comparar la evolución más o menos reciente de las relaciones internacionales con el período anterior a la Segunda Guerra Mundial. En este texto, analizo dos puntos particularmente reveladores, identificando similitudes y diferencias entre los dos períodos.Se puede establecer el paralelo entre la entrevista entre Volodymyr Zelensky y Donald Trump con la del presidente checoslovaco Emil Hácha y Adolf Hitler, recordando al mismo tiempo que, a diferencia de Hitler contra Checoslovaquia, Donald Trump no es un agresor directo de Ucrania, sino que se comporta como el portavoz del Estado agresor, Rusia. En segundo lugar, me interesa la fragmentación y brutalización de los paisajes políticos. Ofrezco una visión, cualesquiera que sean los límites, entre la situación reciente de Francia y algunos elementos que caracterizaron su panorama político en el período de entreguerras.Dans le contexte de tensions actuelles, la comparaison de l’évolution plus ou moins récente des relations internationales avec la période qui précède la IIe Guerre mondiale semble s’imposer à nous à travers :① La montée en puissance des empires/impérialismes/expansionnismes et leur convergence passagère. ② La multiplication des guerres localisées de portée internationale. ③ Le recul du fait démocratique couplé aux dénis croissants du droit international.④ Liés à ceux-ci, la dislocation puis l’effacement majoritaire de la régulation politique et économique (issus de la crise de 1929 pour les années 1930, entamée dès le début des années 1970 dans la sphère capitaliste pour la période récente).⑤ La fragmentation et la brutalisation de la vie politique aux échelles internationale et nationale.⑥ Une redéfinition des modèles, stratégies et techniques de guerre.Sans développer chacun de ces constats, j'évoque dans ce texte deux points particulièrement révélateurs en repérant des similitudes et des différences entre les deux périodes.La mise en parallèle de l’entrevue Volodymyr Zelensky / Donald Trump avec celle réunissant le président tchécoslovaque Emil Hácha et Adolf Hitler peut être faite, tout en rappelant qu'à la différence d'Hitler face à la Tchécoslovaquie, Donald Trump n'est pas un agresseur direct de l'Ukraine mais s'est conduit conduit comme le porte-parole de l'Etat agresseur, la Russie. Dans un second temps, je m'intéresse à la fragmentation et la brutalisation des paysages politiques. Je propose un éclairage, quelles qu'en soient les limites, entre la situation récente de la France et quelques éléments caractérisant son paysage politique dans l'entre-deux guerres.Nel contesto delle tensioni attuali, appare essenziale il confronto tra l'evoluzione più o meno recente delle relazioni internazionali e il periodo precedente la Seconda Guerra Mondiale. In questo testo tratto due punti particolarmente rivelatori, individuando somiglianze e differenze tra i due periodi.Si può fare il parallelo tra l’intervista Volodymyr Zelensky/Donald Trump con quella tra il presidente cecoslovacco Emil Hácha e Adolf Hitler, ricordando che a differenza di Hitler contro la Cecoslovacchia, Donald Trump non è un aggressore diretto dell’Ucraina ma si è comportato come il portavoce dello Stato aggressore, la Russia. In secondo luogo, mi interessa la frammentazione e la brutalizzazione dei panorami politici. Offro uno sguardo, qualunque siano i limiti, tra la recente situazione della Francia e alcuni elementi che caratterizzano il suo panorama politico nel periodo tra le due guerre
DeepGouramic. Reconstitution historique de l’occupation du sol pour évaluer les expositions anciennes auxpesticides
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Phylogenetic Network Diversity Parameterized by Reticulation Number and Beyond.
No full textInternational audienceNetwork Phylogenetic Diversity (Network-PD) is a measure for the diversity of a set of species based on a rooted phylogenetic network (with branch lengths and inheritance probabilities on the reticulation edges) describing the evolution of those species. We consider the Max- Network-PD problem: given such a network, find k species with maximum Network-PD score. We show that this problem is fixed-parameter tractable (FPT) for binary networks, by describing an optimal algorithm running in O(2r log(k)(n + r)) time, with n the total number of species in the network and r its reticulation number. Furthermore, we show that Max-Network-PD is NP-hard for level-1 networks, proving that, unless P=NP, the FPT approach cannot be extended by using the level as parameter instead of the reticulation number
The distribution of minimal fractions on the Stern-Brocot tree
No full textThe Stern-Brocot (SB) tree enumerates all irreducible rationals, uniquely positioned with ties to continued fractions and Christoffel words. In this work, we study a quotiented SB tree, focusing on fractions at levels multiple of 3 and their presence on minimal paths defined by the second-order balancedness of Christoffel words. We describe the distribution of all fractions belonging to a minimal path at these levels, detailing their positions, and provide a comprehensive study of the gaps between consecutive fractions, revealing structural patterns tied to the quotiented tree. In prior work, fractions Fn F n+1 with Fn from the Fibonacci sequence were found to be on a minimal path (zigzag path). Analogously, we study four other minimal paths that define the boundary of the set of all minimal paths.</div
La renégociation du partenariat entre Orano (ex-Areva) et l’Etat du Niger en 2013 : relations avec les parties prenantes et politique RSE.
No full textInternational audienceCet article traite du rôle des parties prenantes de la multinationale Orano dans le contexte des négociations pour le renouvellement du partenariat avec l'Etat du Niger pour l'exploitation de l'uranium. Une cartographie des parties prenantes primaires et secondaires aurait permis à Orano de mener une meilleure négociation mais également d'optimiser la gestion de ses relations avec ses différentes parties prenantes. Une politique RSE plus généreuse et mieux ciblée faciliterait ses relations avec certaines parties prenantes centrifuges comme les ONG et les associations locales. Quant à l'Etat du Niger, l'enjeu fut de rééquilibrer le partenariat pour augmenter ses recettes budgétaires pour une meilleure maîtrise de ses objectifs de développement
Highlights from the 35th European conference on cognitive ergonomics (ECCE 2024)
No full textInternational audienceThis special issue of the Behaviour & Information Technology journal presents highlights from ECCE 2024, the 35th European Conference on Cognitive Ergonomics, held in Paris, France, 7-11 October 2024, at Cnam (National Conservatory of Arts and Crafts).The European Conference on Cognitive Ergonomics (ECCE), founded in 1982, is the leading conference in Europe in the field of Human-Media Interaction and Cognitive Ergonomics. ECCE is the annual conference of EACE, the European Association for Cognitive Ergonomics. It aims to bring together researchers and practitioners from different disciplines to share progress, ideas and debate on emerging ideas in the field of Cognitive Ergonomics.This special issue covers five top-rated papers from the conference, which were invited to submit revised manuscripts to the journal; the conference reviewers provided recommendations for improvement, and the review process continued within the BIT journal, ensuring their high quality. The contributions of the special issue can be grouped into three different areas.Two papers deal with HCI issues in Virtual Reality (VR), in particular multimodal interaction and the perception of physical characteristics of robots. The paper by Nils Ove Beese and colleagues addresses the issue of vibrotactile and auditory feedback in VR. Using ‘ghost search’ tasks of varying difficulty, they show that the non-visual cues improve performance in simple tasks, but not in more complex and dynamic tasks. Stefano Guidi and his colleagues look at the appearance of robots. By modulating the size and proportions of different robots in a VR environment, they address how people perceive the age and cuteness of robots and explore their perception of the robot’s ‘mental characteristics’. They conclude with implications for human-robot interaction, and a discussion about the design of child-like robots.Two papers focus on mobility, one on the user experience of public transport and the other on the ethical perception of autonomous vehicles. Xavier Leonce and his colleagues look at the strategies and behaviours of travellers on station platforms, using the critical incident interview technique. They identify and highlight the core dimensions of passengers’ psychological comfort/discomfort. Augusto Bovesi and his colleagues investigate moral evaluations about decisions taken by human drivers or autonomous vehicles in traffic accident dilemmas. The study shows that moral evaluations of critical traffic accident decisions differ depending on whether human drivers and autonomous vehicles are involved, but that this difference depends on the situation, highlighting the complexity of moral evaluation of autonomous vehicle behaviour.Finally, Yolanda Gómez and her colleagues present a large-scale online econometric experiment on cyberprotection behaviours. They look at the links between the purchase of cyber-insurance and cyber-protection measures, as well as risk-related behaviours and personal characteristics. They show that economic agents do not make decisions based on economic optimisation, and that protection and insurance can be mutually reinforcing, contributing to a better understanding of cyberprotection decision making
ORGANIZING BEYOND CONTROLLING: THE PRAGMATIST CONCEPT OF INQUIRYAS A CRITICAL ALTERNATIVE TO CONTROL
No full textThis article adopts a processual and critical approach to organizing. It questions the tendency to consider "controlling" as an inescapable dimension of the "organizing" process. After defining the distinctive features of the controlling perspective on organizing, we ask whether there may be radical, performative alternatives for the theory and practice of organizing. We then present a longitudinal action research study analyzing the gradual 30-year transformation of a government department into a multinational telecommunications company. It draws on one author's lasting cooperation with the company, to explore problematic situations and potential responses, through the establishment of pluralist communities of inquiry. We suggest that this slow and painful transformation, which caused major financial and workforce morale crises, was characterized by an underground, sometimes invisible but always intense struggle between the controlling perspective and alternative organizing perspectives which met with structural barriers. In the light of this case, we suggest that the pragmatist concept of inquiry provides an exploratory, experimental, participative and transformational organizing perspective, alternative to controlling. The inquiry perspective may also provide the critical performativity school of thought with a promising research topic and open up emancipation and democracy perspectives for the world of organizations
Épisode 9 : Faut-il brûler les ouvrages qui prétendent tirer des leçons de management des séries TV ? Spoiler : certains oui !
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Functional knee positioning in patients with valgus deformity undergoing image-based robotic total knee arthroplasty: Surgical technique
No full textInternational audienceBackground: Functional knee positioning (FKP) represents an innovative personalized approach for total knee arthroplasty (TKA) that reconstructs a three-dimensional alignment based on the optimal balance of soft tissue and bony structures, but it has mostly been described for varus knee deformity. Surgical technique: Valgus deformities present specific challenges due to altered bone remodeling and soft tissue imbalances. Using robotic assistance, FKP enables precise intraoperative assessment and correction of compartmental gaps, accommodating each individual’s unique anatomy and laxities. The distal femoral cut is calibrated for 9 mm resection at the intact medial femoral condyle and adjusted on the lateral side to accommodate bone wear, while the tibial plateau resection aims for 8 mm from the medial side and 4–6 mm from the lateral side. Intraoperative evaluations of mediolateral laxities are performed at extension and 90° flexion. Adjustments are made to femoral and tibial cuts to balance gaps, aiming for 0 mm in posterior stabilized implants and minimal discrepancies in cruciate-retaining designs with lateral gap looser in flexion. Discussion: FKP emphasizes soft tissue-driven adjustments with the use of robotic platforms. Hence, intact soft tissue envelope of the knee is essential. This technique holds significant promise for managing valgus deformities in TKA, but further research is needed to evaluate its functional outcomes