Distributed scene reconstruction from multiple mobile platforms

Recent research on mobile robotics has produced new designs that provide house-hold robots with omnidirectional motion. The image sensor embedded in these devices motivates the application of 3D vision techniques on them for navigation and mapping purposes. In addition to this, distributed cheapsensing systems acting as unitary entity have recently been discovered as an efficient alternative to expensive mobile equipment. In this work we present an implementation of a visual reconstruction method, structure from motion (SfM), on a low-budget, omnidirectional mobile platform, and extend this method to distributed 3D scene reconstruction with several instances of such a platform. Our approach overcomes the challenges yielded by the plaform. The unprecedented levels of noise produced by the image compression typical of the platform is processed by our feature filtering methods, which ensure suitable feature matching populations for epipolar geometry estimation by means of a strict quality-based feature selection. The robust pose estimation algorithms implemented, along with a novel feature tracking system, enable our incremental SfM approach to novelly deal with ill-conditioned inter-image configurations provoked by the omnidirectional motion. The feature tracking system developed efficiently manages the feature scarcity produced by noise and outputs quality feature tracks, which allow robust 3D mapping of a given scene even if - due to noise - their length is shorter than what it is usually assumed for performing stable 3D reconstructions. The distributed reconstruction from multiple instances of SfM is attained by applying loop-closing techniques. Our multiple reconstruction system merges individual 3D structures and resolves the global scale problem with minimal overlaps, whereas in the literature 3D mapping is obtained by overlapping stretches of sequences. The performance of this system is demonstrated in the 2-session case. The management of noise, the stability against ill-configurations and the robustness of our SfM system is validated on a number of experiments and compared with state-of-the-art approaches. Possible future research areas are also discussed

Analysis and design of a prototype to raise awareness about education in bridge schools in India

Dirt, no access to electricity nor to clean tap water, dangerous materials, are some of the characteristics of the environments where unfortunately many indian kids grow up. In the face of the incredibly large ratio of poverty that strikes the country, many families live in unbelievable harsh conditions, mostly being slums located in the surroundings of cities. Even if parents work extremely hard to be able to pursue a better life for their family, in many cases they have to leave their children unattended during long day hours in such hazardous circumstances. Luckily, more and more, enterprises and NGOs are putting their efforts towards granting all kids access to education. Last February, I had the opportunity to travel to Bangalore to participate in a social innovation camp, which intended to improve education conditions in bridge schools. These infrastructures built by Selco foundation, are portable units that are installed in slums for children to have the opportunity to learn, but also to access a solid meal and hygiene conditions. Seeing that in many cases the fear of leaving their kids in an unknown place to be taken care by exterior teachers, scared parents away taking away with them the opportunity of the youngest ones. As a result, a method to raise awareness about education had to be found so as to familiarize the community of its importance, and that’s when this project was born. After getting to know the context and the nature of the problem, a modular board was designed to tackle this issue. Some research confirms that personalized spaces increases the sense of achievement and belonging as well as the recognition and value of external people. Knowing this, the idea was to build a board, that could be used both in interior and exterior environments, to showcase students’ work all along the week. The object has a system that allows hanging the work but there is also a foldable blackboard that serves as a teaching surface as well as an informational panel. There is also a cover that stops the content from getting damaged, and thanks to its lightness and simple method of use it can be rolled-up for easy transportation and storage. Nevertheless, after a first prototype design many technical aspects needed to be worked on. For this reason, this project contains a material research that finds out that the most suitable components are bamboo, PVC and a combination of cellulose and polyethylene to form the bars, the cover and the main surface respectively. Moreover, to prove that the object met the stiffness and resistance requirements, a stress study is carried out which determines the key dimensions the board needs, to be able to sustain the most extreme situation in which a kid could hang himself from the bar. Finally, since many things had changed from the initial model, the design needed to be optimized and new measurements have been established to better adapt the object to the beneficiaries and the environments conditions. Safety parameters, simple local manufacture, low cost, lightness and minimization of the environmental impact are the main points of study that project entails. All in all, this report contains the all the information regarding this technical thorough research, which has met all the set objectives. The final result leaves us with a practical object that could be implemented in a near future to make communities realize the importance of education

Gobernar las ciudades en tiempos de cambio. A propósito del buen gobierno local y de la participación de los ciudadanos en los asuntos públicos.

El autor se plantea una serie de asuntos que hacen al gobierno de las ciudades, pasando revista a la discusión siempre presente sobre la participación ciudadana, el propio concepto de ciudadanía en tiempos de globalización, las relaciones entre los gobiernos locales y los ciudadanos y la necesidad de su reinvención, el proceso de individualización y el desinterés por los asuntos públicos, y la necesidad de establecer nuevas formas de gobierno que integren diferentes miradas desde el Estado y la sociedad civil. En ese sentido, sostiene que la compleja realidad que enmarca actualmente a las autoridades locales les exige un proceso de aprendizaje y de desaprendizaje. Haciendo pie en el concepto de gobernanza, señala que los procesos de participación de los ciudadanos en el gobierno local tampoco han ido acompañados de la formación necesaria para desarrollar todas sus potencialidades. Las redes de cooperación pueden devenir fuentes de gobernanza creativa, radical y responsable, pero antes es necesario que los participantes asimilen los nuevos roles que habrán de asumir, las nuevas formas de trabajo que deberían desarrollar y lo que se espera de ellos. El medio para construir este aprendizaje social son las acciones e interacciones cotidianas de los responsables políticos locales

Improved 3D sparse maps for high-performance SFM with low-cost omnidirectional robots

We consider the use of low-budget omnidirectional platforms for 3D mapping and self-localisation. These robots specifically permit rotational motion in the plane around a central axis, with negligible displacement. In addition, low resolution and compressed imagery, typical of the platform used, results in high level of image noise (_ ∽ 10). We observe highly sparse image feature matches over narrow inter-image baselines. This particular configuration poses a challenge for epipolar geometry extraction and accurate 3D point triangulation, upon which a standard structure from motion formulation is based. We propose a novel technique for both feature filtering and tracking that solves these problems, via a novel approach to the management of feature bundles. Noisy matches are efficiently trimmed, and the scarcity of the remaining image features is adequately overcome, generating densely populated maps of highly accurate and robust 3D image features. The effectiveness of the approach is demonstrated under a variety of scenarios in experiments conducted with low-budget commercial robots

El esclavo de su culpa : comedia en tres actos y en verso

Copia digital. España : Ministerio de Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria., 2021Representada por primera vez en el Teatro Español el día 13 de diciembre de 187

StratoTrans : Unmanned Aerial System (UAS) 4G communication framework applied on the monitoring of road traffic and linear infrastructure

This study provides an operational solution to directly connect drones to internet by means of 4G telecommunications and exploit drone acquired data, including telemetry and imagery but focusing on video transmission. The novelty of this work is the application of 4G connection to link the drone directly to a data server where video (in this case to monitor road traffic) and imagery (in the case of linear infrastructures) are processed. However, this framework is appliable to any other monitoring purpose where the goal is to send real-time video or imagery to the headquarters where the drone data is processed, analyzed, and exploited. We describe a general framework and analyze some key points, such as the hardware to use, the data stream, and the network coverage, but also the complete resulting implementation of the applied unmanned aerial system (UAS) communication system through a Virtual Private Network (VPN) featuring a long-range telemetry high-capacity video link (up to 15 Mbps, 720 p video at 30 fps with 250 ms of latency). The application results in the real-time exploitation of the video, obtaining key information for traffic managers such as vehicle tracking, vehicle classification, speed estimation, and roundabout in-out matrices. The imagery downloads and storage is also performed thorough internet, although the Structure from Motion postprocessing is not real-time due to photogrammetric workflows. In conclusion, we describe a real-case application of drone connection to internet thorough 4G network, but it can be adapted to other applications. Although 5G will -in time- surpass 4G capacities, the described framework can enhance drone performance and facilitate paths for upgrading the connection of on-board devices to the 5G network

Three-dimensional geometry controls division symmetry in stem cell colonies

Proper control of division orientation and symmetry, largely determined by spindle positioning, is essential to development and homeostasis. Spindle positioning has been extensively studied in cells dividing in two-dimensional (2D) environments and in epithelial tissues, where proteins such as NuMA (also known as NUMA1) orient division along the interphase long axis of the cell. However, little is known about how cells control spindle positioning in three-dimensional (3D) environments, such as early mammalian embryos and a variety of adult tissues. Here, we use mouse embryonic stem cells (ESCs), which grow in 3D colonies, as a model to investigate division in 3D. We observe that, at the periphery of 3D colonies, ESCs display high spindle mobility and divide asymmetrically. Our data suggest that enhanced spindle movements are due to unequal distribution of the cell–cell junction protein E-cadherin between future daughter cells. Interestingly, when cells progress towards differentiation, division becomes more symmetric, with more elongated shapes in metaphase and enhanced cortical NuMA recruitment in anaphase. Altogether, this study suggests that in 3D contexts, the geometry of the cell and its contacts with neighbors control division orientation and symmetry

Three-dimensional geometry controls division symmetry in stem cell colonies.

Proper control of division orientation and symmetry, largely determined by spindle positioning, is essential to development and homeostasis. Spindle positioning has been extensively studied in cells dividing in two-dimensional (2D) environments and in epithelial tissues, where proteins such as NuMA (also known as NUMA1) orient division along the interphase long axis of the cell. However, little is known about how cells control spindle positioning in three-dimensional (3D) environments, such as early mammalian embryos and a variety of adult tissues. Here, we use mouse embryonic stem cells (ESCs), which grow in 3D colonies, as a model to investigate division in 3D. We observe that, at the periphery of 3D colonies, ESCs display high spindle mobility and divide asymmetrically. Our data suggest that enhanced spindle movements are due to unequal distribution of the cell-cell junction protein E-cadherin between future daughter cells. Interestingly, when cells progress towards differentiation, division becomes more symmetric, with more elongated shapes in metaphase and enhanced cortical NuMA recruitment in anaphase. Altogether, this study suggests that in 3D contexts, the geometry of the cell and its contacts with neighbors control division orientation and symmetry. This article has an associated First Person interview with the first author of the paper

Prevalencia de hipertensión arterial en la población española a partir de la encuesta europea de salud

La hipertensión arterial (HTA) constituye un problema de salud pública en todos los países desarrollados, lo cual es debido por una parte a su elevada frecuencia y por otra a la gravedad que pueden tener sus posibles complicaciones. Constituye uno de los motivos de consulta más frecuente en Atención Primaria (AP); y es en este punto donde se realizan su diagnóstico, intervención terapéutica y seguimiento. El objetivo de nuestro estudio ha sido conocer la prevalencia de HTA en la población española y conocer los factores de riesgo sociodemográficos que se relacionan con la misma. Para ello, se ha llevado a cabo un estudio descriptivo y transversal a partir de la base de datos recogidos en la Encuesta Europea de Salud de 2014. El análisis de los resultados pone de relieve que una cuarta parte de la población española es hipertensa y prueba la relación de causalidad entre la HTA y los factores de riesgo edad, baja actividad física y la condición de sobrepeso/obesidad. Estos dos últimos, factores de riesgo modificables y por tanto objetivos de necesaria intervención para conseguir una disminución de la prevalencia de hipertensión y una mayor calidad y esperanza de vida en nuestra población de estudio

Energy feeding strategies to shorten the postpartum anoestrous in grazing dairy cows

A prolonged postpartum anoestrus (PPA) is related to a low reproductive efficiency in dairy farms, independently of the calving pattern or feeding system. Postpartum luteal activity resumption is coincident with the onset of lactation when the cow is in negative energy balance, which depending on its magnitude could alter the hypothalamus – pituitary – ovary axis of the animal and prolong the PAA. In this article, some results from experiments that manipulated nutrition as a strategy to shorten the PPA, with emphasis in grazing systems, are briefly reviewed. Available information suggests that manipulation of the level and source of dietary energy are promising tools to reduce the length of the PPA in grazing dairy cows and increase the reproductive efficiency in dairy farms