Three-stream 3D/1D CNN for fine-grained action classification and segmentation in table tennis

This paper proposes a fusion method of modalities extracted from videothrough a three-stream network with spatio-temporal and temporal convolutionsfor fine-grained action classification in sport. It is applied to TTStroke-21dataset which consists of untrimmed videos of table tennis games. The goal isto detect and classify table tennis strokes in the videos, the first step of abigger scheme aiming at giving feedback to the players for improving theirperformance. The three modalities are raw RGB data, the computed optical flowand the estimated pose of the player. The network consists of three brancheswith attention blocks. Features are fused at the latest stage of the networkusing bilinear layers. Compared to previous approaches, the use of threemodalities allows faster convergence and better performances on both tasks:classification of strokes with known temporal boundaries and joint segmentationand classification. The pose is also further investigated in order to offerricher feedback to the athletes.<br

Sports video: Fine-grained action detection and classification of table tennis strokes from videos for MediaEval 2021

This paper presents the baseline method proposed for the Sports Video task part of the MediaEval 2021 benchmark. This task proposes a stroke detection and a stroke classification subtasks. This baseline addresses both subtasks. The spatio-temporal CNN architecture and the training process of the model are tailored according to the addressed subtask. The method has the purpose of helping the participants to solve the task and is not meant to reach stateof-the-art performance. Still, for the detection task, the baseline is performing better than the other participants, which stresses the difficulty of such a task

Fabrication and mechanical testing of a new sandwich structure with carbon fiber network core

The aim is the fabrication and mechanical testing of sandwich structures including a new core material known as fiber network sandwich materials. As fabrication norms for such a material do not exist as such, so the primary goal is to reproduce successfully fiber network sandwich specimens. Enhanced vibration testing diagnoses the quality of the fabrication process. These sandwich materials possess low structural strength as proved by the static tests (compression, bending), but the vibration test results give high damping values, making the material suitable for vibro-acoustic applications where structural strength is of secondary importance e.g., internal panelling of a helicopter

Dose repartition in alveoli, alveolar ducts and bronchi of rats exposed to radon and its progeny, preliminary results

Recently, micronuclei scoring has been performed to estimate doses delivered to the lungs after heterogenous irradiation induced after inhalation of radon and its progeny. These studies were limited to the deep lung after either extraction of alveolar macrophages (AM) by lavage (Taya et al., 1994, Johnson and Newton, 1994) or enzymatic dissociation of lung cells to initiate fibroblast cultures (Khan et al., 1994). Dose estimates were performed after comparison with micronuclei formation induced in vitro by irradiation with alpha particles

Meta-analysis of non-tumour doses for radiation-induced cancer on the basis of dose-rate

Purpose: Quantitative analysis of cancer risk of ionising radiation as a function of dose-rate

Nouvelles méthodes d'identification des fractures par diagraphie acoustique en full wave form

Les outils acoustiques de dernière génération permettent maintenant d'enregistrer l'ensemble des ondes générées par une source acoustique à l'intérieur d'une géométrie cylindrique telle qu'un puits de sondage. Le train d'onde qu'il est alors possible d'analyser se compose successivement de trois composantes majeures (l'onde de compression, de cisaillement et de Stoneley) dont nous avons une représentation pour chaque position de la sonde à l'intérieur du puits. Nous présentons, dans ce texte, trois méthodes originales et rapides (calculs possibles sur le site même) pour identifier, à partir du traitement de l'onde de Stoneley, les fractures ouvertes recoupées par un forage. Nous donnons, dans un premier temps, nos motivations pour le choix unique du traitement de l'onde de Stoneley pour, dans un deuxième temps, exposer les trois méthodes développées et montrer pour chacune d'entre elles une application pratique

Vitesse du son dans les sédiments marins durant les premiers stades du tassement

La vitesse du son est mesurée dans des sédiments marins lors d'une étude expérimentale du tassement. Durant la phase de sédimentation, la vitesse du son diminue légèrement, puis lors de la phase de compaction elle s'accroît avec ta charge et la réduction de porosité (modèles de WOOD (1941) et de NOBES (1989)). Le suivi du phénomène met en évidence le réarrangement graduel de la structure des particules et l'apparition de la rigidité pour une porosité seuil (environ 0,70). La différence de comportement acoustique entre les matériaux argileux et carbonatés résulte essentiellement de la granulométrie qui contrôle la réorganisation des grains