A Robust and Efficient Method for Solving Point Distance Problems by Homotopy

The goal of Point Distance Solving Problems is to find 2D or 3D placements of points knowing distances between some pairs of points. The common guideline is to solve them by a numerical iterative method (\emph{e.g.} Newton-Raphson method). A sole solution is obtained whereas many exist. However the number of solutions can be exponential and methods should provide solutions close to a sketch drawn by the user.Geometric reasoning can help to simplify the underlying system of equations by changing a few equations and triangularizing it.This triangularization is a geometric construction of solutions, called construction plan. We aim at finding several solutions close to the sketch on a one-dimensional path defined by a global parameter-homotopy using a construction plan. Some numerical instabilities may be encountered due to specific geometric configurations. We address this problem by changing on-the-fly the construction plan.Numerical results show that this hybrid method is efficient and robust

Application of two-color LIF thermometry to nucleate boiling

International audienceThe laser-induced fluorescence (LIF) thermometry is applied to measure the temperature field surrounding a single vapor bubble growing at an artificial nucleation site. In order to correct measurement errors due to the non-uniformity of the incident laser intensity, the two-color LIF thermometry technique is used in this nucleate boiling experiment. This technique is based on the use of two fluorescent dyes: the temperature sensitive dye Rhodamine B and the temperature insensitive dye Sulforhodamine-101. The concentration of the dyes is optimized by analyzing the behavior of fluorescence intensities. The mapping between the two images is determined through a geometrical calibration procedure. This technique presents a success in correcting the non uniformities due to the reflection of the light at the bubble surface and to the temperature gradient. The obtained temperature fields show that the two-color LIF is a promising technique in the investigation of nucleate boiling

How Robust Is Discourse Processing for Native Readers? The Role of Connectives and the Coherence Relations They Convey.

While corpus studies have shown that discourse connectives that convey the same coherence relation can display subtle differences, research on online discourse processing has only focused on a rather limited set of connectives. Yet, different connectives - for example, rare or polyfunctional ones - might elicit different reading patterns. In order to explore this assumption, we test the robustness of discourse processing for French native speakers by measuring the way they process causal and concessive sentences that are conveyed by either an appropriate or inappropriate connective. Throughout three experiments, we change important characteristics of the connectives: we first test frequently used connectives (Experiment 1), secondly less frequent ones (Experiment 2), and finally less frequent connectives that are polyfunctional and for which different functions clearly compete (Experiment 3). Our results show that the processing for incoherent items was affected for all connectives, however readers showed altered reading fluency when infrequent connectives were used. We conclude that discourse processing is quite robust and that readers are able to insert meaning conveyed by rare connectives while still showing the highest reading ease with frequent connectives

Pragmatic and syntactic constraints on French causal connectives: An evaluation of native and non-native speakers' sensitivity.

When writing a text, the choice between seemingly equivalent connectives, such as but and however, is not arbitrary: aside from preferences linked to the register or modality of the utterance, there are often pragmatic or syntactic constraints that limit the choice to only one particular connective. For French, theoretical approaches have extensively discussed the syntactic and pragmatic constraints that allow only either parce que (‘because’) or puisque (‘since’). However, experimental findings regarding the actual sensitivity of French speakers to these constraints remain inconclusive. In the current study, we examine the sensitivity of different speaker groups to the constraints associated with the use of parce que and puisque. In a controlled offline-task, we systematically evaluate the sensitivity of a crowd-sourced heterogeneous group of native speakers (Experiment 1) and a group of non-native speakers (Experiment 2). Results show that native speakers are more sensitive to syntactic constraints whereas pragmatic constraints are more equivocal. Nonnative speakers, however, are not sensitive to either of these constraints. In addition, the pragmatically complex connective puisque is extremely problematic for non-native speakers, as even the mapping of a seemingly equivalent connective of their L1 did not warrant a good mastery of its pragmatic functions

Augmented Reality-based Robot Control for Laparoscopic Surgery

Minimally invasive surgery is the standard formany abdominal interventions, with an increasing use of tele-manipulated robots. As collaborative robots enter the field ofmedical interventions, their intuitive control needs to be ad-dressed. Augmented reality can thereby support a surgeonby representing the surgical scene in a natural way. In thiswork, an augmented reality based robot control for laparo-scopic cholecystectomy is presented. A user can interact withthe virtual scene to clip the cystic duct and artery as well asto manipulate the deformable gallbladder. An evaluation wasperformed based on the SurgTLX and system usability scale

Estampe dans les institutions

Rémi Mathis : Il existe de multiples manières d’utiliser l’estampe et donc de la collectionner, d’où une certaine dichotomie bibliothèque/musée notamment, qui correspondent à des usages divers. Pouvez-vous rapidement présenter l’institution où vous travaillez ? Corinne Le Bitouzé : Collection nationale d’images fixes multiples, le département des Estampes est l’héritier des collections royales et s’est constitué par agrégation de différentes collections dont la première est celle de l’abbé Ma..

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Species-specific emergence of H7 highly pathogenic avian influenza virus is driven by intrahost selection differences between chickens and ducks

Highly pathogenic avian influenza viruses (HPAIVs) cause severe hemorrhagic disease in terrestrial poultry and are a threat to the poultry industry, wild life, and human health. HPAIVs arise from low pathogenic avian influenza viruses (LPAIVs), which circulate in wild aquatic birds. HPAIV emergence is thought to occur in poultry and not wild aquatic birds, but the reason for this species-restriction is not known. We hypothesized that, due to species-specific tropism and replication, intrahost HPAIV selection is favored in poultry and disfavored in wild aquatic birds. We tested this hypothesis by co-inoculating chickens, representative of poultry, and ducks, representative of wild aquatic birds, with a mixture of H7N7 HPAIV and LPAIV, mimicking HPAIV emergence in an experimental setting. Virus selection was monitored in swabs and tissues by RT-qPCR and immunostaining of differential N-terminal epitope tags that were added to the hemagglutinin protein. HPAIV was selected in four of six co-inoculated chickens, whereas LPAIV remained the major population in co-inoculated ducks on the long-term, despite detection of infectious HPAIV in tissues at early time points. Collectively, our data support the hypothesis that HPAIVs are more likely to be selected at the intrahost level in poultry than in wild aquatic birds and point towards species-specific differences in HPAIV and LPAIV tropism and replication levels as possible explanations.</p

Some Results of the EU Project FASTGRID

The EU FASTGRID project aimed at improving the REBCO conductor in order to enhance its economical attractiveness for the Superconducting Fault Current Limiter (SFCL). Two approaches were simultaneously investigated: i) the reduction of the tape length through the increase of the electric field during limitation, ii) the reduction of the tape cost through improved yield and higher critical current, including the lowering of the liquid nitrogen bath temperature to 65 K. We carried out a base line using an upgraded THEVA tape. Different approaches have been tried to improve the shunt layer, both with metallic and non-conductive materials. As a first solution, we developed and successfully tested a conductor with a Hastelloy shunt able to withstand 130 Vrms/m during 50 ms at 65 K and low prospective current faults. This conductor was used in two pancake coils. These have been successfully tested at IPH in Berlin. The second shunt solution developed consisted of a ceramic in epoxy matrix coating. Another significant improvement of the tape is the successful implementation of the Current Flow Diverter (CFD) concept with a simple sulfidation process or a deposition of an insulating yttria nanolayer by Inkjet Printing. An increase by one order of magnitude of the Normal Zone Propagation Velocity with respect to tapes without CFD has been measured. A low cost and fast hot spot detection system has also been developed. To reach much higher electric fields under limitation, the FASTGRID team also developed advanced tapes based on a sapphire substrate, which can tolerate ultra-high electric fields up to about 1 kV/m. Validated at laboratory scale, this game-changing technology needs to be implemented in long lengths with an industrial process. One pancake was integrated and tested with a low-cost optical fiber and fast hot spot detection system, developed and patented within the FASTGRID project. This manuscript will showcase most of these FASTGRID results.This work was supported in part by the European Union's Horizon 2020 Research and Innovative Programme under Grant 721019 and in part by the ICMAB acknowledge the Center of Excellence Severo Ochoa under Grant CEX2019-000917-S.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe