1,093 research outputs found
Sparse 3D Point-cloud Map Upsampling and Noise Removal as a vSLAM Post-processing Step: Experimental Evaluation
The monocular vision-based simultaneous localization and mapping (vSLAM) is
one of the most challenging problem in mobile robotics and computer vision. In
this work we study the post-processing techniques applied to sparse 3D
point-cloud maps, obtained by feature-based vSLAM algorithms. Map
post-processing is split into 2 major steps: 1) noise and outlier removal and
2) upsampling. We evaluate different combinations of known algorithms for
outlier removing and upsampling on datasets of real indoor and outdoor
environments and identify the most promising combination. We further use it to
convert a point-cloud map, obtained by the real UAV performing indoor flight to
3D voxel grid (octo-map) potentially suitable for path planning.Comment: 10 pages, 4 figures, camera-ready version of paper for "The 3rd
International Conference on Interactive Collaborative Robotics (ICR 2018)
Responses of Agronomically Important Tropical Crops to the Application of Brassinosteroid
Brassinosteroids (Br) have been shown to favor the growth and reproduction of crops under adverse environmental conditions, which negatively affect their growth and production. In order to solve some of the problems in the field with various perennial crops, the application of a homobrassinolide (HBr) (CIDEF-4) has been investigated under in vitro and ex vitro conditions to evaluate growth at different concentrations in Musa spp. L. and Saccharum officinarum L and in the field with foliar applications in Theobroma cacao L, Mangifera indica L and Coffea arabica L. to evaluate yield and quality of fruits. Morphological and physiological yield components were recorded. The results indicate in the in vitro evaluations, increased regrowth height and ex vitro differences in growth are improved by increasing the number of applications. In cocoa and coffee plants, flowering and yield are influenced. The high concentrations applied did not necessarily increase the crop yield or the combination with potassium nitrate. In mango, the quality of the fruits was better when applying the HBr alone or in combination with nitrate in fruit firmness, and total soluble solids improved
Sugerencias para la toma de datos en eventos de biología reproductiva de aves
Persiste la necesidad de generar y publicar información sobre la historia natural de las aves Ecuatorianas, en este campo es notoria la producción de artículos sobre biología reproductiva de aves, con una gran mayoría de artículos en idioma inglés. Surge la necesidad de estandarizar términos y datos tomados en campo; en el presente detallo las consideraciones que se deberían tomar al momento de observar un evento reproductivo, para no pasar por alto ningún dato y poder realizar comparaciones más completas; también presento diferentes términos, y sus respectivas traducciones, comúnmente usados en los artículos sobre este tema
A mechanism synthesis and modeling for correction of hip dysplasia in medium and large dog breeds
Hip dysplasia is an incurable but treatable disease that affects medium and large dog breeds. It appears as a result of genetic disorders, overweight, and the care given to the dogs. Currently, there are no specialized mechanisms that provide comfort to the life of these pets, while adapting to the canine condition and promoting the use of their hind legs until mobility is completely lost. Therefore, in the present study, a versatile device was synthesized and modeled to help to improve the life quality of dogs, taking as a reference the "German Shepherd" breed. It was designed considering the health and welfare of these animals, taking into account the mobility and safety of their limbs. This device uses a linkage mechanism to provide structural support to the dogs, while allowing for mobility within an specified range of motion. It aims to incorporate a gear and spring system that controls the weight lifted by the device, so that dogs partially use their hind legs. The static and dynamic behavior of this mechanism were mathematically modeled, finding an optimal solution.La displasia de cadera es una enfermedad incurable pero tratable que afecta a razas de perros medianas y grandes. Aparece como resultado de trastornos genéticos, sobrepeso y la atención brindada a los perros. Actualmente, no existen mecanismos especializados que brinden comodidad a la vida de estas mascotas, al tiempo que se adaptan a la condición canina y promueven el uso de sus patas traseras hasta que se pierda por completo la movilidad. Por lo tanto, en el presente estudio, se sintetizó y modeló un dispositivo versátil para ayudar a mejorar la calidad de vida de los perros, tomando como referencia la raza "Pastor Alemán". Fue diseñado teniendo en cuenta la salud y el bienestar de estos animales, considerando la movilidad y la seguridad de sus extremidades. Este dispositivo utiliza un mecanismo de eslabones para proporcionar soporte estructural a los perros, al tiempo que permite la movilidad dentro de un rango de movimiento específico. Proyectando una posible incorporación de un sistema de engranaje y resorte que controla el peso levantado por el dispositivo, para que los perros utilicen parcialmente sus patas traseras. El comportamiento estático y dinámico de este mecanismo fue modelado matemáticamente, encontrando una solución óptima
Desarrollo de un sistema predictivo de potencia fotovoltaica para su utilización en sistemas híbridos
En el trabajo se desarrolla un sistema predictivo de potencia para paneles foto voltaicos (FV) utilizando el concepto de series temporales y lógica difusa. La predicción de la potencia FV puede ser de gran utilidad, debido a que muchos sistemas implementan esta tecnología como una de sus principales fuentes de energía y anticiparse a la potencia que puede generar el conjunto de paneles FV, determina la energía con la que contará el sistema. El sistema desarrollado predice los próximos 5 valores de potencia FV por delante, uno por minuto. La potencia FV es predicha en función de la irradiancia y la temperatura de celda de los paneles FV. Para cada variable se utiliza un sistema de lógica difusa, desarrollado como una función que permite predecir una magnitud cinco minutos posteriores. Cada sistema ingresa como variable de entrada cinco valores de irradiancia y cinco valores de temperatura, consecutivos con un tiempo de muestreo de un minuto. Cada bloque utiliza un sistema de aprendizaje que ajusta la base de conocimiento de los sistemas difusos, utilizando dos años y medio de datos medidos para la irradiancia y un año y medio de medida para la temperatura de celda. Con la información que entregan los bloques, puede determinarse la potencia del panel FV. El trabajo utiliza la irradiancia como variable de entrada, debido a que esta magnitud por lo general tiene un importante historial de información. El tiempo de predicción se debe a que el sistema se desarrolla para mejorar la acción de conexión de un sistema híbrido FV-grupo electrógeno. En el trabajo se observan diferentes medidas, las cuales permiten concluir que el sistema desarrollado muestra una adecuada precisión en la predicción mencionada.A predictive power system for photovoltaic (PV) is developed using the concept of time series and fuzzy logic in this paper. The prediction of PV power can be very useful, because many systems implement this technology as one of their main sources of energy. Also anticipate the power generated by the set of PV panels, and determines the available energy. The developed system predicts the next five PV power values ahead, one every minute. The PV power is predicted based on the irradiance and cell temperature of the PV panels. For each variable, a fuzzy logic system is used, developed as a function that predicts a magnitude five minutes later. Each system import as input variable, five values of irradiance and five values of temperature, consecutive with a sampling time of one minute. Each block uses a learning system that adjusts the knowledge base of fuzzy systems, using two and a half years of measurements for the irradiance and one and a half years of measurements for the cell temperature. With the information what provide the blocks, it possible to determine the power of the PV panel. The paper uses the irradiance as an input variable, because this magnitude usually has significant history information. The action of connecting a generator set FV-hybrid can be improved, if set through the system this “time prediction”. Different sizes are observed in this article to conclude that the developed system shows adequate accuracy in predicting said.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES
Advertising of ultra-processed foods and beverages: children as a vulnerable population
La rápida transición nutricional en América Latina tiene como resultado el aumento pronunciado de sobrepeso y obesidad en los niños. Evidencia reciente muestra que la publicidad de comidas y bebidas ejerce gran influencia en las preferencias alimenticias de los niños. Esta población se torna centro de atención para la industria de alimentos ultra procesados y bebidas, productos comercializados agresivamente. En los países de América Latina, sólo existen reglamentos ineficientes para la publicidad de bebidas y alimentos ultra procesados, y el discurso de auto regulación prevalece sobre los reglamentos legales. Este comentario explora el importante papel de la publicidad en el desarrollo de patrones de dietas no saludables y en la obesidad de niños en América Latina, así como la necesidad de acción gubernamental y participación social en la resolución de este problema de salud pública.A rápida transição nutricional na América Latina tem como resultado o aumento pronunciado de sobrepeso e obesidade nas crianças. Evidência recente mostra que a publicidade de comidas e bebidas tem grande influência nas preferências alimentares das crianças. Essa população torna-se alvo da indústria de alimentos ultraprocessados e bebidas, produtos comercializados agressivamente. Nos países da América Latina, só existem regulamentos ineficientes para a publicidade de bebidas e alimentos ultraprocessados, e o discurso de auto-regulação prevalece sobre os regulamentos legais. Este comentário explora o papel importante da publicidade no desenvolvimento de padrões de dietas não saudáveis e na obesidade das crianças na América Latina, bem como a necessidade de ação governamental e participação social na resolução desse problema de saúde pública.The rapid nutrition transition occurring in Latin America has resulted in a sharp increase of childhood overweight and obesity. Recent evidence has shown that food and beverage advertising has a great influence on children’s eating behavior. This population has become a key target market for the ultra-processed foods and beverages industry, which is marketing products in an aggressive way. Evidence shows that Latin American countries have poor regulation of ultra-processed foods and beverages advertising, where the discourse of self-regulation still prevails over statutory regulations. The following commentary explores how advertising might play an important role in developing unhealthy dietary patterns and obesity in Latin American children, as well as the urgent need for government action and the involvement of civil society to tackle this public health issue
A knowledge management-based conceptual model to improve the level of utilization of ICTs in Mexican SMEs
The current commercial context for the Small and medium-sized enterprises (SMEs) is an ever-changing environment that is strongly influenced by the information and communication technologies (ICTs). This has led enterprises to implement these technologies as supportive tools for their business processes. Nevertheless, a vast number of SMEs have not obtained favorable results in implementing ICTs, since the lack of knowledge about the potential and application of these technologies has made this technological implementation activity prevail as an action oriented to the simple acquisition of equipment and informatic systems with a short-term vision without considering a business strategy. The aim of this paper is to perform a literature review that shows evidence of the low utilization of ICTs in SMEs, particularly in the Mexican environment, which leads to proposing a different approach where enterprises consider Knowledge Management (KM) in the implementation of the informatic technology, leading to a conceptual model to ensure human, organizational and relational capital provide the proper capabilities to complement a strategy that implies carrying out a correct acquisition and application of knowledge that contributes to improving the utilization of ICTs in the business processes
Reconstituted plant viral capsids can release genes to mammalian cells
AbstractThe nucleocapsids of many plant viruses are significantly more robust and protective of their RNA contents than those of enveloped animal viruses. In particular, the capsid protein (CP) of the plant virus Cowpea Chlorotic Mottle Virus (CCMV) is of special interest because it has been shown to spontaneously package, with high efficiency, a large range of lengths and sequences of single-stranded RNA molecules. In this work we demonstrate that hybrid virus-like particles, assembled in vitro from CCMV CP and a heterologous RNA derived from a mammalian virus (Sindbis), are capable of releasing their RNA in the cytoplasm of mammalian cells. This result establishes the first step in the use of plant viral capsids as vectors for gene delivery and expression in mammalian cells. Furthermore, the CCMV capsid protects the packaged RNA against nuclease degradation and serves as a robust external scaffold with many possibilities for further functionalization and cell targeting
3D multi-robot patrolling with a two-level coordination strategy
Teams of UGVs patrolling harsh and complex 3D environments can experience interference and spatial conflicts with one another. Neglecting the occurrence of these events crucially hinders both soundness and reliability of a patrolling process. This work presents a distributed multi-robot patrolling technique, which uses a two-level coordination strategy to minimize and explicitly manage the occurrence of conflicts and interference. The first level guides the agents to single out exclusive target nodes on a topological map. This target selection relies on a shared idleness representation and a coordination mechanism preventing topological conflicts. The second level hosts coordination strategies based on a metric representation of space and is supported by a 3D SLAM system. Here, each robot path planner negotiates spatial conflicts by applying a multi-robot traversability function. Continuous interactions between these two levels ensure coordination and conflicts resolution. Both simulations and real-world experiments are presented to validate the performances of the proposed patrolling strategy in 3D environments. Results show this is a promising solution for managing spatial conflicts and preventing deadlocks
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