PACE: an Experimental Web-Based Audiovisual Application using FDL

International audienceThis paper describes the PACE experimental multimedia application that aims at providing automatic tools for web browsing of television program collections; experimentations are currently in progress with a fifty-four Le Grand Échiquier show collection. PACE has been built with the FERIA framework and relies on multiple automatic analysis tools. It is generic enough to easily adapt to other collections. Emphasis is made on the new audiovisual documents description language FDL as it is the core part of FERIA, with a particular attention paid on how it operates in PACE

Visibilité et présence de l’image dans l’espace ecclésial

Cet ouvrage met au cœur de son propos une interrogation simple : dans l’organisation complexe de l’espace de l’église médiévale, les emplacements choisis pour les images qui ornent les murs et les objets n’offrent pas toujours la possibilité de voir celles-ci, d’en déchiffrer le contenu. Certaines semblent réservées à des groupes de l’assemblée stationnant dans des espaces spécifiques, d’autres ne sont pas visibles depuis les principales zones affectées aux fidèles ou aux clercs, d’autres encore sont situées trop haut. Le rapport, a priori évident, entre représentation et visibilité se trouve donc souvent démenti, appelant alors une nouvelle notion, celle de présence. Analyser la tension existant entre ces trois catégories – figuration, visibilité et présence – implique une étude croisée des œuvres figurées, des monuments et des sources écrites. Les notions de mobilité et de fixité permettent également de prendre en compte les multiples jeux d’échelles à l’œuvre dans ce lieu rituel qu’est l’église, impliquant des objets, des manuscrits, des dispositifs liturgiques, des gestes, des déplacements physiques, dialoguant avec un décor appliqué au corps même du monument, épousant l’immobilité de l’architecture. Les cinq chapitres thématiques qui organisent ce volume mettent en regard différents cas issus de l’Occident médiéval et de l’Orient byzantin, selon une chronologie longue (de l’Antiquité tardive à la fin du Moyen Âge), dans une volonté de décloisonner les disciplines et les aires géographiques afin de tirer tous les enseignements d’une approche transversale de l’image médiévale

The LHCb upgrade I

The LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software

Quantifying the Benefit and Measuring Residual Uncertainties of MLC Tracking During the First Clinical Implementation for Lung Cancer Radiation Therapy

Radiation therapy is a cancer treatment that involves the use of radiation to kill cancer cells and shrink the tumour. One of the main issues that this field is facing is that of respiratory-induced tumour motion. In the presence of motion, the radiation beam can miss the tumour and instead irradiate healthy tissues leading to radiation toxicities. For these reasons, positional uncertainty associated with motion is generally recognized as intrinsic to radiotherapy. With the advent of fast computing technology, it is now feasible to treat cancer patients in a safer way, by tracking the position of their tumour and adapting the radiation beam in real-time. This thesis presents the developments of frontier technology for guided lung cancer radiation therapy. More specifically, this research details the first clinical use of multi-leaf collimator (MLC) tracking for lung cancer patients, a technology that can track and adapt to the patient’s breathing pattern during the irradiation. To demonstrate the feasibility and the benefits of MLC tracking, a clinical trial involving a cohort of patients diagnosed with lung cancer was conducted. This clinical trial, called LIGHT SABR, treated seventeen patients with lung implanted electromagnetic transponders with the primary objective to test whether MLC tracking is feasible, and the secondary objective to evaluate transponder implantation safety/migration and potential dosimetric benefits of MLC tracking over ITV-based treatment. The major finding of this work is thesis is that is that MLC tracking can be implemented in a safe clinical environment for patients with fast and erratic tumour motion patterns

PACE: an Experimental Web-Based Audiovisual Application using FDL

This paper describes the PACE experimental multimedia application that aims at providing automatic tools for web browsing of television program collections; experimentations are currently in progress with a fifty-four ”Le Grand Échiquier ” show collection. PACE has been built with the FERIA framework and relies on multiple automatic analysis tools. It is generic enough to easily adapt to other collections. Emphasis is made on the new audiovisual documents description language FDL as it is the core part of FERIA, with a particular attention paid on how it operates in PACE. 1

Studying the Visual Representation of Microgestures

International audienceThe representations of microgestures are essentials for researchers presenting their results through academic papers and system designers proposing tutorials to novice users. However, those representations remain disparate and inconsistent. As a first attempt to investigate how to best graphically represent microgestures, we created 21 designs, each depicting static and dynamic versions of 4 commonly used microgestures (tap, swipe, flex and hold). We first studied these designs in a quantitative online experiment with 45 participants. We then conducted a qualitative laboratory experiment in Augmented Reality with 16 participants. Based on the results, we provide design guidelines on which elements of a microgesture should be represented and how. In particular, it is recommended to represent the actuator and the trajectory of a microgesture. Also, although preferred by users, dynamic representations are not considered better than their static counterparts for depicting a microgesture and do not necessarily result in a better user recognitio

Real-time high spatial resolution dose verification in stereotactic motion adaptive arc radiotherapy

Purpose: Radiation treatments delivered with real-time multileaf collimator (MLC) tracking currently lack fast pretreatment or real-time quality assurance. The purpose of this study is to test a 2D silicon detector, MagicPlate-512 (MP512), in a complex clinical environment involving real-time reconfiguration of the MLC leaves during target tracking. Methods: MP512 was placed in the center of a solid water phantom and mounted on a motion platform used to simulate three different patient motions. Electromagnetic target tracking was implemented using the Calypso system (Varian Medical Systems, Palo Alto, CA, USA) and an MLC tracking software. A two-arc VMAT plan was delivered and 2D dose distributions were reconstructed by MP512, EBT3 film, and the Eclipse treatment planning system (TPS). Dose maps were compared using gamma analysis with 2%/2 mm and 3%/3 mm acceptance criteria. Dose profiles were generated in sup-inf and lateral directions to show the agreement of MP512 to EBT3 and to highlight the efficacy of the MLC tracking system in mitigating the effect of the simulated patient motion. Results: Using a 3%/3 mm acceptance criterion for 2D gamma analysis, MP512 to EBT3 film agreement was 99% and MP512 to TPS agreement was 100%. For a 2%/2 mm criterion, the agreement was 95% and 98%, respectively. Full width at half maximum and 80%/20% penumbral width of the MP512 and EBT3 dose profiles agreed within 1 mm and 0.5 mm, respectively. Patient motion increased the measured dose profile penumbral width by nearly 2 mm (with respect to the no-motion case); however, the MLC tracking strategy was able to mitigate 80% of this effect. Conclusions: MP512 is capable of high spatial resolution 2D dose reconstruction during adaptive MLC tracking, including arc deliveries. It shows potential as an effective tool for 2D small field dosimetry and pretreatment quality assurance for MLC tracking modalities. These results provide confidence that detector-based pretreatment dosimetry is clinically feasible despite fast real-time MLC reconfigurations