Analyzing the performance of marathon runners is a study of vital importance for optimizing athletes' results. The COVID-19 pandemic and its measures against its spread resulted in a drastic change in the way of life of most of the population, including athletes, who saw their training habits modified, in addition to the possible short-, medium-, and long-term consequences that infection with the new virus could cause in their health. This study analyzes through normality analysis, Kolmogorov-Smirnov, Chi-square tests, and the Wasserstein distance the finish times and paces of more than 900k athletes (filtered by age range and gender) in major marathons in different cities around the world to determine the effects of the pandemic on their performance. The analysis using the Wasserstein distance shows that the period of years with the most significant differences in race pace was 2019-2021 (pre- and postpandemic years) in practically all the marathons analyzed, while the analysis using chi-square shows differences in that period of years in some cities, age, and gender groups. We found significant differences between 2019 and 2021 in pace behavior in some age and gender groups, shown by the Wasserstein distance and chi-square test.

Our study analyzes the wearable device preferences of long-distance runners and examines the differences between genders, regions (the USA and Europe), age, and performance. We have analyzed 237,336 records from eight of the world’s most famous marathons between 2016 and 2019. Our study takes into account the device model, family, and type. We have found that Garmin devices are the most widely used in this type of race, accounting for more than 75% of the records. Women generally prefer more economical, non-specific, and lighter devices, while men increasingly use specialized trail and multisport devices. Moreover, we have observed differences in device preferences among different age groups and performance levels. The manufacturers of this type of technology are making strides toward sustainability, with a focus on energy efficiency, sustainable materials, durability, environmental certifications, and recycling programs.

A Mixed Reality (MR) application using an optical see-through headset was developed to assess short-term spatial memory. A study with 29 participants was conducted. Data from this study were compared to two previous studies using mobile Augmented Reality (AR) and Virtual Reality (VR) with headsets. When comparing the three technologies (MR, AR, VR) for the performance variables, there were no statistically significant differences for either the total number of correctly placed objects or the total number of attempts. However, the MR application required more time than the AR and VR applications in the evaluation phase and more time than the VR application in the learning phase. Our arguments for the longer time are the novelty of the MR application for the participants and the characteristics of the applications. The key results from the MR study include the following: (1) the objects used in the MR application were correctly positioned on a map, which implies that the memory acquired with the MR application is effectively transferred to the user’s mental map; (2) for the performance variables, there were no significant differences in the results by gender; (3) and the usability rating decreased with computer experience. The results show that the MR application is effective for spatial memory assessment and was well rated by the participants. The three technologies, along with suitable hardware, are effective for spatial memory assessment. However, MR using optical see-through headsets offers advantages over mobile AR and VR using headsets, discussed in this publication.

In this paper, the first virtual reality (VR) photography application that incorporates elements on panoramic images to assess short-term spatial memory is presented. It also allows the interaction with these elements. A study was conducted (N = 50) to compare participants' performance outcomes and subjective experience when using a VR application with and without panoramic photography. The results show that both applications are effective in assessing short-term spatial memory. The results with panoramic photography include: 1) It was effective for short-term recall since, after using the application, the participants were able to verbally recall the objects and place them without significant differences with respect to the objects correctly placed; 2) The performance outcomes were independent of age and gender; 3) The perceived level of presence was directly related to experiencing less cybersickness when using the application; 4) The level of satisfaction was directly related to perceived enjoyment, concentration, usability, competence, calmness, and expertise; 5) The more the familiarity with VR applications, the less the perceived cybersickness. Finally, the application offers two main advantages: 1) The evaluators can customize the environment by adding as many elements as desired to the panoramic photograph; 2) It could be especially suitable for groups with reduced mobility.

This article determines the precision of the most relevant GPS models used in marathon races. It uses public data of the participants in the leading marathons. We have retrieved 73 865 records from 85 GPS models. There are differences in the precision obtained by road GPS models compared with models designed for trail races and mobile phones. The precision also depends on the finish time: The longer the race takes, the higher the error. No evidence of differences among the studied brands appear. The results can be helpful for manufacturers to get field information about the behavior of the devices in real conditions. And it can be beneficial for end-users also since the data help the buy decision. On the other hand, with this information, athletes could have available more accurate measures about their pace and other data during a marathon.

In this paper, we present the Virtual Maze Task that assesses spatial short-term memory in adults involving physical movement and immersion.For physical movement, we used a real bicycle.For immersion, we used a VR HMD.We compared the exposure to the task using two different interaction types (physical active vs. physical inactive conditions).The performance and sensations of the participants were compared in both conditions.We also compared the performance on the virtual task with classical neuropsychological tests.A total of 89 adults participated in our study.The participants' ability to learn a route within the Virtual Maze Task was tested.Then, the participants assessed their experience scoring the following aspects: interaction and satisfaction.The data were analyzed and we found no differences in satisfaction and interaction scores between the physical active and the physical inactive conditions.However, the condition used for interaction affected the score obtained in the task.There were also significant effects of gender and/or interaction used in other measures of performance on the task.Finally, the performance on the task correlated with the performance on other classical neuropsychological tests for the assessment of short-term memory and spatial memory.

This paper presents the MnemoCity task, which is a 3D application that introduces the user into a totally 3D virtual environment to evaluate spatial short-term memory. A study has been carried out to validate the MnemoCity task for the assessment of spatial short-term memory in children, by comparing the children’s performance in the developed task with current approaches. A total of 160 children participated in the study. The task incorporates two types of interaction: one based on standard interaction and another one based on natural interaction involving physical movement by the user. There were no statistically significant differences in the results of the task using the two types of interaction. Furthermore, statistically significant differences were not found in relation to gender. The correlations between scores were obtained using the MnemoCity task and a traditional procedure for assessing spatial short-term memory. Those results revealed that the type of interaction used did not affect the performance of children in the MnemoCity task.

In this paper, we present an application that uses two visualization systems. The first one has a large passive display. In the second system, we use a virtual reality head mounted display (Oculus Rift). We report the results of a study to determine the feeling of immersion in an application for testing spatial memory. 168 adults participated in the study. They are 25 . 28 ± 4 . 07 years old. After testing each system, they answered a questionnaire about their feeling of immersion in the 3D environment. We found statistically significant differences between the visualization systems. The participants gave higher scores when using Oculus Rift that using passive 3D. Then, we can conclude that the participants have perceived better the 3D with the Oculus Rift.

For years, stereoscopy has been related to photogrammetry in topography. However, these methods are not efficient for virtual globes because the effect is only visible from one view point and this restricts interactivity. By using synthetic image techniques in order to generate stereo-paired images, we can produce visible effects from any view point. In this paper, we present a comparative study of stereoscopic techniques in virtual globes supported by a test carried out among 51 participants. Three devices were used: anaglyphs, an autostereoscopic screen and a quadbuffer system. The aim was to determine which one of the three devices causes a deeper feeling of immersion and which one can be more efficient in a virtual globe. Results show considerable differences between the quadbuffer system and the other devices. The mentioned system causes in the user a stronger feeling of depth and immersion in the virtual globe.

We introduce a new representation for modeling and rendering plants and trees. The representation is multiresolution and can be automatically generated and rendered in an efficient way. For the trunk and branches we procedurally build a multiresolution structure that preserves the visual appearance of a tree, when rendered at different levels of detail. For the leaves we build a hierarchy of images by pre-processing the botanical tree structure. Unlike other representations, the visual quality of our representation does not depend on viewing position and direction. Our models can be applied to any computer graphics area that requires modeling outdoor scenes like interactive walkthroughs and fly-by’s, realistic rendering, simulation and computer games.

This paper presents an Augmented Reality (AR) game for learning words. Thirty-two children played the AR game and the equivalent real game. We have compared the results of the two games. The results indicate that children did not found significant differences between the two games except for one question, but 81% of the children liked most the AR game.

La representacion de datos vectoriales (carreteras, lagos, ciudades, etc) es una parte fundamental en los sistemas de informacion geografica, tanto para visualizar la informacion como para procesos de analisis. La gran cantidad de informacion adquirida en formato vectorial provoca que, en la mayoria de los casos, la visualizacion sea masiva o incluso que no quepa toda la informacion en memoria principal. En este trabajo se presentan algunas tecnicas para la representacion eficiente de datos vectoriales en 3D. El trabajo se centra en las tecnicas utilizadas para datos vectoriales de tipo punto y plantea su extension para polilineas y poligonos. Abarca desde las estructuras de datos multirresolucion empleadas y los algoritmos de generacion hasta la visualizacion en sistemas de informacion geografica 3D.

La tecnología multitáctil ha comenzado a introducirse en nuestra vida cotidiana, impulsada principalmente por los smartphones . Algunas compañías han lanzado al mercado pantallas de ordenador multitáctiles, presentando formas alternativas de interacción. Los principales problemas de esta tecnología emergente son el alto coste y el tamaño de los dispositivos. Dichos problemas la restringen habitualmente a ferias, empresas o laboratorios de investigación. Recientemente, grupos de entusiastas e investigadores han publicado algunas técnicas, manuales y vídeos de cómo construir pantallas multitáctiles. El problema es que la mayoría de ellas están basadas en un proyector, por lo que normalmente ocupan demasiado espacio. En este trabajo presentamos una pantalla multitáctil portátil de bajo coste. Tiene tanto un volumen como un peso reducidos y es fácil de construir.

En este artículo, se presenta una librería multiplataforma desarrollada en C++ y Java sobre el grafo de escena de OpenSceneGraph que permite visualizar terrenos y planetas tridimensionales con multirresolución dependiente de la vista de forma eficiente y dinámica. La librería es capaz de visualizar datos de elevación o de textura (ortofotos o datos vectoriales rasterizados) tanto de archivos locales como de servidores remotos, sin necesidad de realizar un preproceso previo a la visualización. Nuestra finalidad es aportar un conjunto de herramientas software para la visualización y manipulación tridimensional de datos geoespaciales integrada en un Sistema de Información Geográfica.

Se presenta una librería multiplataforma capaz de mostrar en un sistema de información geográfica datos vectoriales tridimensionales utilizando las técnicas de aceleración que ofrecen los grafos de escena. La representación de datos vectoriales es de especial interés, siendo un factor clave en diversas áreas del análisis geográfico. Se aportan herramientas de edición y visualización 3D capaz de dibujar puntos, líneas, polígonos, extrusión de geometrías y figuras geométricas básicas de una manera eficiente.

En este articulo, presentamos un sistema de edicion y manipulacion de objetos 3D multiplataforma y de codigo libre, programado sobre OpenSceneGraph. El sistema esta compuesto por una libreria, que permite la manipulacion de los objetos mediante operaciones de traslacion, rotacion y escalado, y una aplicacion de edicion de escenas 3D basada en la libreria, y desarrollada como una extension de la plataforma Eclipse. 1. Introduccion La Conselleria de Infraestructura y Transportes (CIT) de la Generalitat Valenciana esta realizando actualmente una migracion de sus sistemas informaticos a software libre. Como parte de este proceso, se decidio crear un Sistema de Informacion Geografica (SIG) propio, llamado gvSIG [gvs03]. Un SIG es un sistema utilizado para capturar, almacenar, analizar y gestionar datos espacialmente referenciados. Uno de los proyectos que forman gvSIG consiste en la creacion de una visualizacion en 3D del SIG. El conjunto de librerias base de este proyecto esta siendo desarrollado en el

Light fields are an image-based representation that represents objects using sets of digital images. Light fields are usually comprised of 4D radiance data that can be used for 3D rendering or 4D display on autostereoscopic and certain types of volumetric displays. We present a modeling and rendering system for spherical isotropic light fields. These are made of images captured with cameras placed on a sphere's surface looking inwards. The system implements a multiresolution representation for both the spatial and the directional domains of the light field. This representation supports continuous levels of detail and adaptive frame rate control.

We present a client/server system that is able to display 3D scenes on handheld devices. At the server we extract the geometry that is visible for each client and send it. We also extract texture and material information. The clients, running on mobile devices, use that information to render realistic images. Our geometry extraction algorithm employs multiresolution and view-dependent simplification. We present results of our system running on PocketPC 2003 PDAs.

Modeling and rendering of trees has recently received a lot of attention. Models have been developed that allow photorealistic rendering of trees at interactive frame rates. However, little attention has been devoted to expressive rendering of these models. In this work we present a multiresolution model designed specifically to speed up painterly rendering of trees. Our method proposes a novel clustering technique based on the computation of nested convex hulls. We employ variable multiresolution to obtain efficient models that contain higher resolution representations for the outside of the tree and lower resolution representations for the inner parts. This variable multiresolution method mimics the techniques used by traditional artists to paint trees.