Investigating the Interaction between Helmet Field of View and Steering Behavior in a Novel Motorcycle Simulator

While helmet wearing reduces the severity of injuries in motorcycle crashes, it may also increase the likelihood of getting involved into a traffic accident through a reduction in the rider’s field of view. We thus investigated the perceptual effects of helmet wearing when riding a motorcycle. The task consisted of negotiating curves in a fixed-based simulator while the helmet visor vertical dimension and need to check the handlebar-mounted speedometer were manipulated. Decreasing the vertical aperture below roughly 30 deg significantly impaired a rider’s ability to maintain their lane position and speed; with the effect of aperture being significantly greater when speedometer checking was required. The present findings provide further support for near/far point models of steering and help to quantify the tradeoff between physical and perceptual effects in helmet design

Modeling the wind circulation around mills with a Lagrangian stochastic approach

This work aims at introducing model methodology and numerical studies related to a Lagrangian stochastic approach applied to the computation of the wind circulation around mills. We adapt the Lagrangian stochastic downscaling method that we have introduced in [3] and [4] to the atmospheric boundary layer and we introduce here a Lagrangian version of the actuator disc methods to take account of the mills. We present our numerical method and numerical experiments in the case of non rotating and rotating actuator disc models. We also present some features of our numerical method, in particular the computation of the probability distribution of the wind in the wake zone, as a byproduct of the fluid particle model and the associated PDF method

Drivers' decision-making when attempting to cross an intersection results from choice between affordances

International audienceIn theory, a safe approach to an intersection implies that drivers can simultaneously manage two scenarios: they either choose to cross or to give way to an oncoming vehicle. In this article we formalize the critical time for safe crossing (CT cross) and the critical time for safe stopping (CT stop) to represent crossing and stopping possibilities, respectively. We describe these critical times in terms of affordances and empirically test their respective contribution to the driver's decision-making process. Using a driving simulator, three groups of participants drove cars with identical acceleration capabilities and different braking capabilities. They were asked to try to cross an intersection where there was an oncoming vehicle, if they deemed the maneuver to be safe. If not, they could decide to stop or, as a last resort, make an emergency exit. The intersections were identical among groups. Results showed that although the crossing possibilities (CT cross) were the same for all groups, there were between-group differences in crossing frequency. This suggests that stopping possibilities (CT stop) play a role in the driver's decision-making process, in addition to the crossing possibilities. These results can be accounted for by a behavioral model of decision making, and provide support for the hypothesis of choice between affordances

A multi‐scale analysis of basketball throw in virtual reality for tracking perceptual‐motor expertise

To benefit from virtual reality (VR) as a complementary tool for training, coaches must determine the proper tools and variables for tracking sports performance. We explored the basketball shooting at several scales (basket-ball, ball-player, and player systems) by monitoring success-rate, and ball and body kinematics. We measured how these scales of analysis allowed tracking players' expertise and perceptual sensitivity to basket distance. Experienced and novice players were instructed to naturally throw and swish an instrumented ball in a stereoscopically rendered virtual basket. We challenged their perceptual-motor systems by manipulating the distance of the virtual basket while keeping the surrounding environment unchanged. The success-rate accounted for the players' shooting adjustments to the manipulation of basket distance and allowed tracking their expertise. Ball kinematics also reflected the manipulation of distance and allowed detecting gender, but did not reflect the players' expertise. Finally, body kinematics variables did not echo players' adjustments to the distance manipulation but reflected their expertise and gender. The results gained at each scale of analysis are discussed with regard to the simulator's construct, biomechanical, and psychological fidelity

Fonctions Géométriques Principaleset Paramétrisation de Forme Adaptéeà l' Optimisation en Aérodynamique

Ce rapport s'insère dans le cadre d'études en conception optimale de forme aérodynamique pour lequelles on cherche des paramétrisations géométriques adaptées à l'écoulement . On présente ici une méthode pour identifier un ensemble de fonctions de forme visant à capter la sensibilité de l'écoulement à la géométrie. On modélise la perturbation du champ de vitesse consécutive à une perturbation de la forme par le gradient d'une fonction potentielle harmonique. En simplifiant les conditions aux limites, on aboutit à un problème de valeurs propres dont les vecteurs propres associés représentent discrètement les fonctions de forme principales. La méthode est illustrée par le calcul de ces fonctions dans le cas d'un écoulement autour d'un profil NACA0012. Ultérieurement, ces fonctions de forme serviront de base fonctionnelle pour représenter la perturbation du profil dans un calcul d'optimisation d'un critère aérodynamique

Perceptual-motor coupling betwwen Helicopter and ship during ship deck landing maneuvers

Helicopter ship landings are challenging operations appealing for further researches and innovations to help pilots safely dealing with a variety of environmental, visual and operational contexts. Indeed, landing on ship not only differs from land-based landings in the extent that the landing area is located on the flight deck, which is most of the time oscillating, but also because the visual environment is often impoverished (e.g., rain, fog, night conditions). In order to improve safety at deck-landing, the French Aerospace Lab (ONERA) and the French Defense Agency (DGA) are interested in understanding pilots’ perceptual-motor strategies involved in a such complex task so as to design ecological interfaces assisting pilots’ landing maneuvers

Proximal femoral fractures in centenarians. A retrospective analysis of 39 patients

BACKGROUND: A corollary of the current population ageing in France is an increase in proximal femoral fractures (PFFs), particularly among centenarians. The outcomes of PFFs in centenarians in France are unknown. We therefore conducted a retrospective study of centenarians with PFFs both to assess: (1) assess clinical outcomes according to geriatric and trauma scores, (2) and to determine whether routine surgery is warranted. HYPOTHESIS: Morbidity and mortality in a single-centre cohort of centenarians with surgically treated PFFs are consistent with previous reports. MATERIAL AND METHOD: We retrospectively reviewed the data of 33 women and 6 men aged 100 years or over who were treated surgically for PFFs at a single-centre between 2008 and 2014. Of the 39 patients, 15 were living at home and 24 in an institution at the time of the injury. Mean (range) values were 3.30 (0-7) for the Parker Mobility Score, 5.84 (0-12) for the Katz index, and 7.46 (2-12) for the Mini Nutritional Assessment (MNA). Mean time from injury to surgery was 1.7 days (0-12). The 26 extra-capsular fractures were managed by internal fixation and the 13 intra-capsular fractures by hip arthroplasty (n=12) or screw fixation (n=1). RESULTS: After a mean follow-up of 23±14 months (6-60 months), 29 patients had died, including 3 within 48h, 10 within 3 months, and 15 within 1 year. Sequential mortality rates were 33.3% within the first 3 months, 26.9% from months 4 to 9, and 42.2% within the first year. Early dislocation occurred in 3 patients and surgical-site infection in 2 patients. Other complications were heart failure (n=1), confusional state (n=2), pneumonia (n=2), and pyelonephritis (n=2). DISCUSSION: A PubMed search identified five studies of PFFs in more than 10 centenarians, of which only 2 provided detailed information on postoperative general and local morbidity related to the surgical treatment. Our hypothesis was confirmed for 3-month and 1-year mortality rates, which were at the lower ends of previously reported ranges. Local complications related directly to surgery were considerably more common in our study. PFFs in centenarians carry a high risk of death. Despite the absence of a control group, our data support surgery as the best treatment option. LEVEL OF EVIDENCE: IV, retrospective study

A simplified interventional mapping system (SIMS) for the selection of combinations of targeted treatments in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is a leading cause of death worldwide. Targeted monotherapies produce high regression rates, albeit for limited patient subgroups, who inevitably succumb. We present a novel strategy for identifying customized combinations of triplets of targeted agents, utilizing a simplified interventional mapping system (SIMS) that merges knowledge about existent drugs and their impact on the hallmarks of cancer. Based on interrogation of matched lung tumor and normal tissue using targeted genomic sequencing, copy number variation, transcriptomics, and miRNA expression, the activation status of 24 interventional nodes was elucidated. An algorithm was developed to create a scoring system that enables ranking of the activated interventional nodes for each patient. Based on the trends of co-activation at interventional points, combinations of drug triplets were defined in order to overcome resistance. This methodology will inform a prospective trial to be conducted by the WIN consortium, aiming to significantly impact survival in metastatic NSCLC and other malignancies

Analyse multi-échelle du lancer au basketball en réalité virtuelle pour détecter l'expertise perceptivo-motrice

International audienceTo benefit from virtual reality (VR) as a complementary tool for training, coaches must determine the proper tools and variables for tracking sports performance. We explored the basketball shooting at several scales (basket-ball, ball-player, and player systems) by monitoring success-rate, and ball and body kinematics. We measured how these scales of analysis allowed tracking players' expertise and perceptual sensitivity to basket distance. Experienced and novice players were instructed to naturally throw and swish an instrumented ball in a stereoscopically rendered virtual basket. We challenged their perceptual-motor systems by manipulating the distance of the virtual basket while keeping the surrounding environment unchanged. The success-rate accounted for the players' shooting adjustments to the manipulation of basket distance and allowed tracking their expertise. Ball kinematics also reflected the manipulation of distance and allowed detecting gender, but did not reflect the players' expertise. Finally, body kinematics variables did not echo players' adjustments to the distance manipulation but reflected their expertise and gender. The results gained at each scale of analysis are discussed with regard to the simulator's construct, biomechanical, and psychological fidelity

Prospective control of free-throw in basketball: Validation of a virtual setup and de-correlation methodology

International audiencePrevious basketball studies are unclear on whether free throws are pre-programmed (Vickers, 1996) or regulated online (de Oliveira, Huys, Oudejans, van de Langenberg, & Beek, 2007). In line with the law of control framework (Warren, 1988), we are in favor the second solution. This would imply that visual information concerning the sufficiency of the current movement to score a basket should so as to correct the movement pattern if necessary. While eye-tracking measurements or visual occlusion methodology have provided strong evidences in favor of the online hypothesis, biasing visual perception by mean of virtual reality should ultimately settle the issue