Un cabinet expose-t-il nécessairement une collection ? Le cas du Cabinet des fleurs de Jean Franeau, un cabinet de regrets

International audienc

Montbert – La Grambaudière

Les travaux occasionnés par le remembrement de la commune de Montbert, ont révélé un abondant débitage moustérien, au nord du village de la Grambaudière, dans un petit vallon de rive droite du Lognon. Deux veines de quartzite de textures différentes étant observables immédiatement en amont, les sondages ont cherché à déterminer la position de l’industrie, par rapport à ces dernières. Trois coupes de terrain, distantes d’une dizaine de mètres, permirent d’observer le même schéma stratigraphiqu..

Uniform Random Sampling of Traces in Very Large Models

This paper presents some first results on how to perform uniform random walks (where every trace has the same probability to occur) in very large models. The models considered here are described in a succinct way as a set of communicating reactive modules. The method relies upon techniques for counting and drawing uniformly at random words in regular languages. Each module is considered as an automaton defining such a language. It is shown how it is possible to combine local uniform drawings of traces, and to obtain some global uniform random sampling, without construction of the global model

Light-mediated strong coupling between a mechanical oscillator and atomic spins one meter apart

Engineering strong interactions between quantum systems is essential for many phenomena of quantum physics and technology. Typically, strong coupling relies on short-range forces or on placing the systems in high-quality electromagnetic resonators, restricting the range of the coupling to small distances. We use a free-space laser beam to strongly couple a collective atomic spin and a micromechanical membrane over a distance of one meter in a room-temperature environment. The coupling is highly tunable and allows the observation of normal-mode splitting, coherent energy exchange oscillations, two-mode thermal noise squeezing and dissipative coupling. Our approach to engineer coherent long-distance interactions with light makes it possible to couple very different systems in a modular way, opening up a range of opportunities for quantum control and coherent feedback networks.Comment: 24 pages, 9 figure

Stationary time correlations for fermions after a quench in the presence of an impurity

We consider the quench dynamics of non-interacting fermions in one dimension in the presence of a finite-size impurity at the origin. This impurity is characterized by general momentum-dependent reflection and transmission coefficients which are changed from ${\sf r}_0(k), {\sf t}_0(k)$ to ${\sf r}(k), {\sf t}(k)$ at time $t=0$. The initial state is at equilibrium with ${\sf t}_0(k)=0$ such that the system is cut in two independent halves with ${\sf r}_0^R(k)$, ${\sf r}_0^L(k)$ respectively to the right and to the left of the impurity. We obtain the exact large time limit of the multi-time correlations. These correlations become time translationally invariant, and are non-zero in two different regimes: (i) for $x=O(1)$ where the system reaches a non-equilibrium steady state (NESS) (ii) for $x \sim t$, i.e., the ray-regime. For a repulsive impurity these correlations are independent of ${\sf r}_0^R(k)$, ${\sf r}_0^L(k)$, while in the presence of bound states they oscillate and memory effects persist. We show that these nontrivial relaxational properties can be retrieved in a simple manner from the large time behaviour of the single particle wave functions.Comment: Main text: 7 pages, 3 figures. Supp. Mat.: 31 pages, 4 figure

Mind wandering dynamic in automated environments and its influence on out-of-the-loop situations

Des niveaux d'automatisation élevés sont intégrés dans les environnements critiques pour satisfaire la demande croissante de systèmes plus sûrs. Cette philosophie déplace les opérateurs vers un rôle de supervision et crée de nouveaux problèmes appelés problèmes de performance liés à la sortie de boucle (SDB). L'émergence de pensées sans lien avec ici et maintenant, ou divagation attentionnelle (DA), pourrait affecter les opérateurs dans des situations de SDB par le biais du découplage perceptuel induit. Cette thèse a étudié la dynamique de la DA dans les situations de SDB et son influence sur les opérateurs. Nous avons en premier lieu examiné les preuves dans la littérature pointant vers un lien entre le problème de performance lié à la SDB et la DA. Nous avons complété cette analyse théorique en rapportant la tendance des pilotes (collectée avec un questionnaire) à rencontrer plus de problèmes avec leur pilote automatique pour ceux ayant une plus grande propension au MW non lié à la tâche. Nous avons ensuite mené trois expériences dans des conditions de SDB. Nous avons observé une augmentation significative des épisodes de DA dans les situations de SDB quelle que soit la fiabilité du système, par rapport aux conditions manuelles. Les épisodes de DA étaient également accompagnés d'un découplage perceptuel vis-à-vis de la tâche créé par la DA non lié à la tâche. Ce découplage était visible sur des rapports de demande mentale ainsi que les signaux oculométriques et encéphalographiques. Dans l'ensemble, nos résultats démontrent la possibilité d'utiliser des marqueurs physiologiques de la DA dans des environnements de SDB complexes. Nous discutons de nouvelles perspectives d'utilisation des marqueurs de la DA pour caractériser les problèmes de performance liés à la SDB. Sans vouloir arrêter aveuglément l'émergence de la DA, qui pourrait être bénéfique pour les opérateurs, les recherches futures devraient se concentrer sur la conception de systèmes capables de gérer la DA et d'identifier les informations nécessaires pour faciliter la rentrée de l'opérateur dans la boucle de contrôle.Higher levels of automation are progressively integrated in critical environments to satisfy the increasing demand for safer systems. Such philosophy moves operators to a supervisory role, also called out-of-the-loop (OOTL) situations. Unfortunately, OOTL situations also create a new kind of human-machine interaction issues, called OOTL performance problem. The dramatic consequences of OOTL performance problem stress the need to identify which mechanisms could influence their appearance. The emergence of thoughts unrelated to the here and now, labeled mind wandering (MW), could affect operators in OOTL situations through the perceptual decoupling induced. This thesis investigates MW dynamic in OOTL situations and its influence on operators. We firstly reviewed the evidences in the literature underlining a link between OOTL performance problem and MW. We completed theoretical insights by reporting pilots' tendency (collected with a questionnaire) to encounter more problems with autopilots when experiencing more task-unrelated MW. Then, we conducted three experiments in OOTL conditions using an obstacle avoidance task. With non-expert population and sessions longer than 45 minutes, we observed a significant increase of MW in OOTL situations compared to manual conditions, independently of system reliability. MW episodes were also accompanied by a perceptual decoupling from the task induced by task-unrelated MW. This decoupling was visible on reports of mental demand as well as oculometric (pupil size, blinks) and encephalographic (N1 component, alpha activity) signals. Overall, our results demonstrate the possibility to use physiological markers of MW in complex OOTL environments. We discuss new perspectives towards the use of MW markers to characterize the OOTL performance problem. Instead of blindly stopping MW episodes, which could have benefits for operators, future research should focus on designing systems able to cope with MW and identify information needed to facilitate the reentry in the control loop when needed

Je T\u27Aime Means I Love You

Title onlyhttps://scholarsjunction.msstate.edu/cht-sheet-music/1414/thumbnail.jp

HMC and underdamped Langevin united in the unadjusted convex smooth case

We consider a family of unadjusted generalized HMC samplers, which includes standard position HMC samplers and discretizations of the underdamped Langevin process. A detailed analysis and optimization of the parameters is conducted in the Gaussian case, which shows an improvement from $1/\kappa$ to $1/\sqrt{\kappa}$ for the convergence rate in terms of the condition number $\kappa$ by using partial velocity refreshment, with respect to classical full refreshments. A similar effect is observed empirically for two related algorithms, namely Metropolis-adjusted gHMC and kinetic piecewise-deterministic Markov processes. Then, a stochastic gradient version of the samplers is considered, for which dimension-free convergence rates are established for log-concave smooth targets over a large range of parameters, gathering in a unified framework previous results on position HMC and underdamped Langevin and extending them to HMC with inertia