Improved depth recovery in consumer depth cameras via disparity space fusion within cross-spectral stereo.

We address the issue of improving depth coverage in consumer depth cameras based on the combined use of cross-spectral stereo and near infra-red structured light sensing. Specifically we show that fusion of disparity over these modalities, within the disparity space image, prior to disparity optimization facilitates the recovery of scene depth information in regions where structured light sensing fails. We show that this joint approach, leveraging disparity information from both structured light and cross-spectral sensing, facilitates the joint recovery of global scene depth comprising both texture-less object depth, where conventional stereo otherwise fails, and highly reflective object depth, where structured light (and similar) active sensing commonly fails. The proposed solution is illustrated using dense gradient feature matching and shown to outperform prior approaches that use late-stage fused cross-spectral stereo depth as a facet of improved sensing for consumer depth cameras

Georg Trakl : le cri de la correspondance

Malgré une relative indigence documentaire (152 lettres conservées), l'étude de l'œuvre épistolaire du poète autrichien Georg Trakl (1887-1914) conduit au cœur de la question qui fut sa grande affaire : celle du langage, pour la conquête duquel il lutta douloureusement toute sa vie. Incapable de soutenir la tension née de la dissociation existentielle du sujet, l'écriture épistolaire voit voler en éclats sa double fonctionnalité traditionnelle, abandonnant en quelque sorte à la création poétique la fonction expressive du langage (discours), ne retenant pour elle, progressivement, que la fonction communicative, à travers le cri (acte) qu'elle adresse au monde. Dans cette distribution singulière, car paradoxale, se constitue, tragiquement, une œuvre double, dissociée, par quoi le sujet lutte pour son unité en même temps qu'il en consacre son impossibilité

In vivo assessment of the mechanical properties of the child cortical bone using quantitative computed tomography

The mechanical properties of the rib cortical bone are extremely rare on children due to difficulties to obtain specimens to perform conventional tests. Some recent studies used cadaveric bones or bone tissues collected during surgery but are limited by the number of samples that could be collected. A non-invasive technique could be extremely valuable to overcome this limitation. It has been shown that a relationship exists between the mechanical properties (apparent Young’s modulus and ultimate strength) and the bone mineral density (assessed using Quantitative Computed Tomography, QCT), for the femur and recently by our group for the adult ribs ex vivo. Thus the aim of this study was to assess the mechanical properties of the child rib cortical bone using both QCT images in vivo and the previous relationship between bone mineral density and mechanical properties of the rib cortical bone. Twenty-eight children were included in this study. Seven age-groups have been considered (1, 1.5, 3, 6, 10, 15, 18 years old). The QCT images were prescribed for various thoracic pathologies at the pediatric hospital in Lyon. A calibration phantom was added to the clinical protocol without any modifications for the patient. The protocol was approved by the ethical committee. A 3D reconstruction of each thorax was performed using the QCT images. A custom software was then used to obtain cross-sections to the rib midline. The mean bone mineral density was then computed by averaging the Hounsfield Units in a specific cross-section and by converting the mean value (Hounsfield Units) in bone mineral density using the calibration phantom. This bone mineral density was assessed for the 6th rib of each subject. Our relationship between the bone mineral density and the mechanical properties of the rib cortical bone was used to derive the mechanical properties of the child ribs in vivo. The results give values for the apparent Young’s modulus and the ultimate strength. The mechanical properties increase along growth. As an example the apparent Young’s modulus in the lateral region ranges from 7 GPa +/-3 at 1 year old up to 13 GPa +/- 2 at 18 years old. These data are in agreement with the few previous values obtained from child tissues. This methodology opens the way to in vivo measurement of the mechanical properties of the child cortical bone based on calibrated QCT images

Utiliser la perception de l’effort pour prescrire l’exercice au cours de tâches motrices des membres supérieurs

Objectif : La perception de l’effort (PE) est utilisée dans la prescription et la supervision d’exercice lors de tâches locomotrices et de résistance. Néanmoins, son utilisation pour prescrire et superviser l’exercice lors de tâches motrices des membres supérieurs reste incertaine. Cette étude vise à tester ces possibilités. Méthodes : Quarante participants se sont portés volontaires. Dans l’expérience 1, quatre intensités de PE ont été utilisées pour prescrire l’exercice dans une version modifiée du Test du Box and Block (TBB) et d’une tâche de pointage. La possibilité de superviser l’exercice a été étudiée en imposant trois niveaux de difficultés via un tempo ou un poids et en mesurant les changements de PE associés. L’expérience 2 réplique la possibilité de prescrire l’exercice avec l’intensité de la PE et étudie les effets de l’ajout d’un poids sur l’avant-bras dominant sur la performance et la PE au cours de la version standardisée du TBB. L’activité musculaire, les fréquences cardiaque et respiratoire ont été mesurées. Résultats : Dans l’expérience 1, l’augmentation de l’intensité de la PE pour prescrire l’exercice a induit une augmentation de la performance et l’augmentation de la difficulté des tâches a augmenté la PE du participant. Dans l’expérience 2, la possibilité d’utiliser la PE pour prescrire l’intensité de l’exercice a été répliquée. La réalisation du TBB avec un poids additionnel révèle un maintien de la performance au prix d’une PE plus élevée. Dans les deux expériences, l’activité musculaire constitue le meilleur corrélat physiologique de la PE. Conclusion : Nos résultats suggèrent que la PE est un outil efficace pour prescrire et superviser l’exercice au cours de tâches motrices des membres supérieurs.Purpose: While the perception of effort (PE) is widely used to prescribe and monitor exercise during locomotor and resistance tasks, its use to prescribe and monitor exercise during upper-limb motor tasks remains unclear. This study aimed to test these possibilities. Methods: Forty participants volunteered in two experiments. In experiment 1, by using a modified version of the box and block test (BBT) and a pointing task, four PE intensities were used to prescribe the exercise. The possibility of monitoring the exercise was investigated during these tests by monitoring changes in the rating of PE in response to three task difficulties manipulated with different movement tempo and weights added on the exercising forearm. Experiment 2 replicated the possibility of prescribing the exercise with the PE intensity during the BBT and explored the impact of adding weight on the exercising forearm on performance and PE during the standardized version of the BBT. Muscle activation, heart rate and respiratory frequencies were recorded. Results: In experiment 1, increasing the PE intensity to prescribe the exercise induced an increased performance between each intensity. Increasing task difficulty with higher movement tempo and adding weight on the forearm increased the rating of PE. Experiment 2 replicated the possibility to use PE intensity for exercise prescription during the BBT. When completing the BBT with an additional weight on the forearm, performance was maintained at a cost of a higher PE. In both experiments, muscle activation was the best physiological marker of PE. Conclusion: Our results suggest that PE is an efficient tool to prescribe and monitor exercise during upper-limb motor tasks

Improved Depth Recovery In Consumer Depth Cameras via Disparity Space Fusion within Cross-spectral Stereo

We address the issue of improving depth coverage in consumer depth cameras based on the combined use of cross-spectral stereo and near infra-red structured light sensing. Specifically we show that fusion of disparity over these modalities, within the disparity space image, prior to disparity optimization facilitates the recovery of scene depth information in regions where structured light sensing fails. We show that this joint approach, leveraging disparity information from both structured light and cross-spectral sensing, facilitates the joint recovery of global scene depth comprising both texture-less object depth, where conventional stereo otherwise fails, and highly reflective object depth, where structured light (and similar) active sensing commonly fails. The proposed solution is illustrated using dense gradient feature matching and shown to outperform prior approaches that use late-stage fused cross-spectral stereo depth as a facet of improved sensing for consumer depth cameras

Multi-Object Detection, Pose Estimation and Tracking in Panoramic Monocular Imagery for Autonomous Vehicle Perception

While active sensing such as radars, laser-based ranging (LiDAR) and ultrasonic sensors are nearly ubiquitous in modern autonomous vehicle prototypes, cameras are more versatile because they are nonetheless essential for tasks such as road marking detection and road sign reading. Active sensing technologies are widely used because active sensors are, by nature, usually more reliable than cameras to detect objects, however they are lower resolution, break in challenging environmental conditions such as rain and heavy reflections, as well as materials such as black paint. Therefore, in this work, we focus primarily on passive sensing technologies. More specifically, we look at monocular imagery and to what extent, it can be used as replacement for more complex sensing systems such as stereo, multi-view cameras and LiDAR. Whilst the main strength of LiDAR is its ability to measure distances and naturally enable 3D reasoning; in contrast, camera-based object detection is typically restricted to the 2D image space. We propose a convolutional neural network extending object detection to estimate the 3D pose and velocity of objects from a single monocular camera. Our approach is based on a siamese neural network able to process pair of video frames to integrate temporal information. While the prior work has focused almost exclusively on the processing of forward-facing rectified rectilinear vehicle mounted cameras, there are no studies of panoramic imagery in the context of autonomous driving. We introduce an approach to adapt existing convolutional neural networks to unseen 360° panoramic imagery using domain adaptation via style transfer. We also introduce a new synthetic evaluation dataset and benchmark for 3D object detection and depth estimation in automotive panoramic imagery. Multi-object tracking-by-detection is often split into two parts: a detector and a tracker. In contrast, we investigate the use of end-to-end recurrent convolutional networks to process automotive video sequences to jointly detect and track objects through time. We present a multitask neural network able to track online the 3D pose of objects in panoramic video sequences. Our work highlights that monocular imagery, in conjunction with the proposed algorithmic approaches, can offer an effective replacement for more expensive active sensors to estimate depth, to estimate and track the 3D pose of objects surrounding the ego-vehicle; thus demonstrating that autonomous driving could be achieved using a limited number of cameras or even a single 360° panoramic camera, akin to a human driver perception

Exploiting the Brønsted acidity of phosphinecarboxamides for the synthesis of new phosphides and phosphines

International audienc

Real-time Classification of Vehicle Types within Infra-red Imagery

Real-time classification of vehicles into sub-category types poses a significant challenge within infra-red imagery due to the high levels of intra-class variation in thermal vehicle signatures caused by aspects of design, current operating duration and ambient thermal conditions. Despite these challenges, infra-red sensing offers significant generalized target object detection advantages in terms of all-weather operation and invariance to visual camouflage techniques. This work investigates the accuracy of a number of real-time object classification approaches for this task within the wider context of an existing initial object detection and tracking framework. Specifically we evaluate the use of traditional feature-driven bag of visual words and histogram of oriented gradient classification approaches against modern convolutional neural network architectures. Furthermore, we use classical photogrammetry, within the context of current target detection and classification techniques, as a means of approximating 3D target position within the scene based on this vehicle type classification. Based on photogrammetric estimation of target position, we then illustrate the use of regular Kalman filter based tracking operating on actual 3D vehicle trajectories. Results are presented using a conventional thermal-band infra-red (IR) sensor arrangement where targets are tracked over a range of evaluation scenarios

Characteristics, practice patterns, and outcomes in patients with acute hypertension: European registry for Studying the Treatment of Acute hyperTension (Euro-STAT)

Although effective strategies are available for the management of chronic hypertension, less is known about treating patients with acute, severe elevations in blood pressure. Using data from the European registry for Studying the Treatment of Acute hyperTension (Euro-STAT), we sought to evaluate 'real-life' management practices and outcomes in patients who received intravenous antihypertensive therapy to treat an episode of acute hypertension.Journal Articleinfo:eu-repo/semantics/publishe