A Query Language for Exploratory Analysis of Video-Based Tracking Data in Padel Matches

Recent advances in sensor technologies, in particular video-based human detection, object tracking and pose estimation, have opened new possibilities for the automatic or semi-automatic per-frame annotation of sport videos. In the case of racket sports such as tennis and padel, state-of-the-art deep learning methods allow the robust detection and tracking of the players from a single video, which can be combined with ball tracking and shot recognition techniques to obtain a precise description of the play state at every frame. These data, which might include the court-space position of the players, their speeds, accelerations, shots and ball trajectories, can be exported in tabular format for further analysis. Unfortunately, the limitations of traditional table-based methods for analyzing such sport data are twofold. On the one hand, these methods cannot represent complex spatio-temporal queries in a compact, readable way, usable by sport analysts. On the other hand, traditional data visualization tools often fail to convey all the information available in the video (such as the precise body motion before, during and after the execution of a shot) and resulting plots only show a small portion of the available data. In this paper we address these two limitations by focusing on the analysis of video-based tracking data of padel matches. In particular, we propose a domain-specific query language to facilitate coaches and sport analysts to write queries in a very compact form. Additionally, we enrich the data visualization plots by linking each data item to a specific segment of the video so that analysts have full access to all the details related to the query. We demonstrate the flexibility of our system by collecting and converting into readable queries multiple tips and hypotheses on padel strategies extracted from the literature.This research was funded by the Spanish Ministry of Science and Innovation and FEDER funds, grant number PID2021-122136OB-C21, MCIN/AEI/10.13039/501100011033/FEDER, UE

Distribución óptima del transporte intermodal: aplicación a la exportación de perecederos

This paper discusses the benefits using intermodal transport for fruit and vegetables. Multi-Criteria Decision Making techniques are applied for optimal allocation between land or intermodal transport. Also a sensitivity analysis is made for knowing changing priorities in decision-makers (exporters) to encourage a modal shift. The results show savings in intermodal transport costs in relation to land transport cost. However the exporter must assume increased time of delivery of goods.Agribusiness, Agricultural and Food Policy, F14, Q17,

Animation Fidelity in Self-Avatars: Impact on User Performance and Sense of Agency

The use of self-avatars is gaining popularity thanks to affordable VR headsets. Unfortunately, mainstream VR devices often use a small number of trackers and provide low-accuracy animations. Previous studies have shown that the Sense of Embodiment, and in particular the Sense of Agency, depends on the extent to which the avatar's movements mimic the user's movements. However, few works study such effect for tasks requiring a precise interaction with the environment, i.e., tasks that require accurate manipulation, precise foot stepping, or correct body poses. In these cases, users are likely to notice inconsistencies between their self-avatars and their actual pose. In this paper, we study the impact of the animation fidelity of the user avatar on a variety of tasks that focus on arm movement, leg movement and body posture. We compare three different animation techniques: two of them using Inverse Kinematics to reconstruct the pose from sparse input (6 trackers), and a third one using a professional motion capture system with 17 inertial sensors. We evaluate these animation techniques both quantitatively (completion time, unintentional collisions, pose accuracy) and qualitatively (Sense of Embodiment). Our results show that the animation quality affects the Sense of Embodiment. Inertial-based MoCap performs significantly better in mimicking body poses. Surprisingly, IK-based solutions using fewer sensors outperformed MoCap in tasks requiring accurate positioning, which we attribute to the higher latency and the positional drift that causes errors at the end-effectors, which are more noticeable in contact areas such as the feet.Comment: Accepted in IEEE VR 202

Estimating Player Positions from Padel High-Angle Videos: Accuracy Comparison of Recent Computer Vision Methods

The estimation of player positions is key for performance analysis in sport. In this paper, we focus on image-based, single-angle, player position estimation in padel. Unlike tennis, the primary camera view in professional padel videos follows a de facto standard, consisting of a high-angle shot at about 7.6 m above the court floor. This camera angle reduces the occlusion impact of the mesh that stands over the glass walls, and offers a convenient view for judging the depth of the ball and the player positions and poses. We evaluate and compare the accuracy of state-of-the-art computer vision methods on a large set of images from both amateur videos and publicly available videos from the major international padel circuit. The methods we analyze include object detection, image segmentation and pose estimation techniques, all of them based on deep convolutional neural networks. We report accuracy and average precision with respect to manually-annotated video frames. The best results are obtained by top-down pose estimation methods, which offer a detection rate of 99.8% and a RMSE below 5 and 12 cm for horizontal/vertical court-space coordinates (deviations from predicted and ground-truth player positions). These results demonstrate the suitability of pose estimation methods based on deep convolutional neural networks for estimating player positions from single-angle padel videos. Immediate applications of this work include the player and team analysis of the large collection of publicly available videos from international circuits, as well as an inexpensive method to get player positional data in amateur padel clubs.This work has been partially funded by the Spanish Ministry of Economy and Competitiveness and FEDER under grant TIN2017-88515-C2-1-R

The Role and Relevance of Experimentation in Informatics

Informatics is a relatively young eld within sci- ence and engineering. Its research and develop- ment methodologies build on the scientic and de- sign methodologies in the classical areas, often with new elements to it. We take an in-depth look at one of the less well-understood methodologies in infor- matics, namely experimentation. What does it mean to do experiments in in- formatics? Does it make sense to `import' tradi- tional principles of experimentation from classical disciplines into the eld of computing and informa- tion processing? How should experiments be docu- mented? These are some of the questions that are treated. The report argues for the key role of empiri- cal research and experimentation in contemporary Informatics. Many IT systems, large and small, can only be designed sensibly with the help of experiments. We recommend that professionals and students alike are well-educated in the prin- ciples of sound experimentation in Informatics. We also recommend that experimentation protocols are used and standardized as part of the experimental method in Informatic

Mesh Repair with Topology Control

In this research report, we propose a new method to convert a triangular mesh with geometrical and topological defects into a 2-manifold, whose topology (genus and number of connected components) is controlled by the user. We start by converting the input mesh into a thin layer of face-connected voxels; then the topology of this voxel set can be modified by the user thanks to morphological operators of different orders; at last the fixed voxel set is converted back into a triangular mesh, which both is a 2-manifold and have the desired topology

The nuclear receptor LXRα controls the functional specialization of splenic macrophages.

Macrophages are professional phagocytic cells that orchestrate innate immune responses and have considerable phenotypic diversity at different anatomical locations. However, the mechanisms that control the heterogeneity of tissue macrophages are not well characterized. Here we found that the nuclear receptor LXRα was essential for the differentiation of macrophages in the marginal zone (MZ) of the spleen. LXR-deficient mice were defective in the generation of MZ and metallophilic macrophages, which resulted in abnormal responses to blood-borne antigens. Myeloid-specific expression of LXRα or adoptive transfer of wild-type monocytes restored the MZ microenvironment in LXRα-deficient mice. Our results demonstrate that signaling via LXRα in myeloid cells is crucial for the generation of splenic MZ macrophages and identify an unprecedented role for a nuclear receptor in the generation of specialized macrophage subsets

La gestión de las emociones de los estudiantes universitarios y el rendimiento académico en los exámenes

Introducción: El miedo, la ansiedad y la angustia, son las principales causas de la disminución del rendimiento académico de los estudiantes ante un examen.Propósitos: Analizar la relación entre las emociones y el rendimiento académico de estudiantes en los exámenes para poder planificar una gestión emocional y mejorar el rendimiento académico.Desarrollo: Se realizó un estudio descriptivo de corte transversal a alumnos universitarios con un muestreo no probabilístico. Se validó una encuesta y los datos se analizaron estadísticamente empleando un Estudio Descriptivo de Variables involucradas e Inferencia Estadística por medio de Test de Independencia. Aplicando un modelo de gestión ontológica, se organizaron talleres realizando las actividades: contrato ontológico, visualización, tabla de metas, rueda académica, análisis de situación reales, trabajos grupales, reestructuración cognitiva, gestión corporal.Resultados: Se obtuvieron 167 encuestas (septiembre-octubre/2019). Se estableció que la variable instancia de examen está relacionada a la variable emociones. El 35% de las personas que respondieron la encuesta indicaron que la principal emoción que tienen antes de un examen fue la ansiedad, seguida por el miedo, la inseguridad y la angustia. Los factores familiares son los que más afectaban a los estudiantes en sus rendimientos académicos. Se dictaron dos talleres empleando herramientas del coaching ontológico y se logró que los estudiantes lleven aprendizajes que les permitirán cambiar el observador que están siendo y poder gestionar las emociones que afectan su rendimiento académico.Conclusiones: Los talleres que se dictaron empleando herramientas para la gestión emocional en los alumnos fue satisfactoria ya que se cumplieron los estándares preestablecidos, y las personas se llevaron herramientas para la implementación en sus vidas.Fil: Gusils Leon, Carlos Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres" (p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Sánchez, Fabiana del Valle. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: García Biagosch, Luigi. Coaching Para la Conciencia; ArgentinaFil: Andujar, Pía. Coaching Para la Conciencia; ArgentinaFil: Barrionuevo, José. Coaching Para la Conciencia; Argentin