Pair Density Waves in coupled doped two-leg Ladders

Motivated by Resonant X-ray scattering experiments in cuprate ladder materials showing charge order modulation of period $\lambda=3$ and 5 at specific hole densities, we investigate models involving the electronic t-J ladders and bosonic chains coupled via screened Coulomb repulsion. Extensive density matrix renormalization group calculations applied to the ladders/chains supplemented by a self-consistent mean-field treatment of the inter-ladder/chain coupling provide quantitative estimates of the charge order for $\lambda=3,4$ and 5. As previously proposed, such patterns correspond to the emergence of pair density waves which stem from the strong electronic correlations. We comment on the existence of a $\lambda=4$ modulation not seen so far in experiment.Comment: 4 pages, 4 figure

Robust parameter estimation of density functions under fuzzy interval observations

International audienceThis study deals with the derivation of a probabilistic parametric model from interval data using the maximum likelihood principle. In contrast with classical techniques such as the EM algorithm, that define a precise likelihood function by computing the probability of observations viewed as a collection of non-elementary events, our approach presupposes that each imprecise observation underlies a precise one, and that the uncertainty that pervades its observation is epistemic, rather than representing noise. We define an interval-valued likelihood function and apply robust optimisation methods to find a safe plausible estimate of the statistical parameters. The approach is extended to fuzzy data by optimizing the average of lower likelikoods over a collection of data sets obtained from cuts of the fuzzy intervals, as a trade off between optimistic and pessimistic interpretations of fuzzy data. The principles of this method are compared with those of other existing approaches to handle incompleteness of observations, especially the EM technique

Seeking stability of supply chain management decisions under uncertain criteria

The leading theme of MOSIM’12 is "Performance, Interoperability and Safety for sustainable development"International audienceThis paper tackles the question of the anticipation of the supply chain partner's decisional behaviour under uncertain criteria. In other words, we propose a model to support sequential decisions under uncertainty where the decision maker has to make hypothesis about the decision criteria. For example, Hurwicz criterion weights extreme optimism and pessimism positions and a classic criticism of this criterion consisting in the difficulty of the weight assessment and the involving decision instability. To achieve this, we present a method based on fuzzy representation of weight vision. Finally, the model allows sequential decision of a Decision Tree to be compute thanks a pignistic probabilities treatment of the fuzzy representation of the decision maker optimism-pessimism index. This approach is illustrated through an industrial case study

Decision support with ill-known criteria in the collaborative supply chain context

International audienceIn the field of Supply Chain Risk Management, the attitude of managers toward risk affect the tactical decision-making process in collaborative supply chains under an uncertain environment, concerning especially capacity levels, lot-sizing rules, purchasing strategies, production scheduling,…, etc. The issue can be formulated as a sequential decision problem under uncertainty where the customer decisions affect the decisions made by the supplier. In this paper we deal with two kinds of uncertainties. The first one is the uncertainty on the indicators of performance (which are not comparable) used by the decision maker to choose a solution (for example: service quality or inventory cost). Hence, we propose an approach based on subjective probability to evaluate the probability that a decision is optimal for the first actor and the probability that it is optimal for both. From these two evaluations, we propose a ranking function to help the first actor to take into account the second one when selecting a decision. The second kind of uncertainty pertains to the demand. A classical criterion under total uncertainty is Hurwicz criterion where a weight expresses a degree of pessimism. Nevertheless, the degree of pessimism is itself ill-known. Thus, it becomes difficult to take into account the behavior of the actors. Hence, we propose an approach based on possibility theory and the so-called pignistic transform, which computes a subjective probability distribution over the criteria. Then, we apply the method used for uncertain criterion. This approach is illustrated through an example and an industrial case study

Nueil-les-Aubiers – Bocage Bressuirais

Après des découvertes importantes au xixe s. et au début du xxe s., le Bocage Bressuirais a connu une longue période de recherche archéologique atone. Par conséquent, la carte archéologique montre un « vide » visible dans le secteur pour les périodes antérieures au Moyen Âge central. Les prospections pédestres entamées sur la commune de Combrand en 2016 et poursuivies sur celle de Nueil-les-Aubiers en 2017 visent à améliorer l’image de l’occupation du sol aux différentes périodes en sélection..

La métallurgie du fer dans les Deux-Sèvres et la Vienne

Identifiant de l'opération archéologique : 204702 Date de l'opération : 2009 (PT) Les prospections archéologiques pédestres menées en 2009 dans les départements des Deux-Sèvres et de la Vienne s’inscrivent dans le cadre de ma thèse préparée à l’université de Poitiers, sous la direction de Nadine Dieudonné-Glad, et débutée à la fin de l’année 2007. Son sujet porte sur la métallurgie du fer chez les Pictons de La Tène finale à la fin de la période romaine. Cette campagne de prospections 2009 es..

Real-time Kirchhoff migration for ultrasound imaging of the bone cortex

International audienceIn this paper, we explore the feasibility of real-time ultrasound imaging of the cortex of a long bone. We show that it is possible in vivo with a conventional clinical ultrasound probe and a fully programmable ultrasound scanner. The ultrasound images are reconstructed using Kirchhoff migration and taking into account the elastic anisotropy of cortical bone tissue. An image rate of 1 image per second was achieved

Vendor Managed inventory, from concept to processes, for an unified view

International audienceIn a supplier-customer relationship, Vendor Managed Inventory (VMI) is currently used to monitor the customer's inventory replenishment. However the integration of VMI implies consequences on the collaboration process that links the different planning processes of each partner. This paper proposes a unified view of the VMI: beyond the short term pull system inventory replenishment, partners have to share their vision of the demand, their requirements and their constraints to fix middle/long term common objectives for each article concerned by VMI. There are many ways to specify these links between VMI and partner's planning processes