6 resultados para climbing

em Universidad Politécnica de Madrid


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Nuts are heavy and nutritious seeds that need animals to be successfully dispersed. Most studies address nut removal by a single animal species once seeds fall onto the ground. However, nuts are also accessible before the seed drop and usually to a wide guild of seed foragers. This study examines the factorscontrollingarborealseedremoval in oak–beechforests within the whole guild of nut foragers. We found that seed-dispersing rodents (Apodemus sylvaticus) were the main acorn removers in the oaks (up to 3.75 m height), with a rapid seed encounter and a high removal rate. However, rodents did not climb the beech trees, probably due to their smoother bark in comparison to oak bark and/or the lower nutritional value of beechnuts with regard to acorns. Jays (Garrulus glandarius) were more abundant in oak stands (both dense and scattered) and clearly preferred acorns to beechnuts whereas nuthatches (Sitta europaea) were more abundant in beech stands and preferred beechnuts to acorns. Non-storing birds such as great tits (Parus major) also removed acorns and beechnuts, especially in the stands where oaks are dominant. Jays and rodents preferred sound seeds over insect-infested seeds but such a preference was not found for nuthatches. This study highlights that pure beech stands showed a reduced guild of arboreal nut foragers in comparison to oak stands. This different guild could probably affect the spatial patterns of seed dispersal, with a proportionally higher number of long dispersal events for acorns (mostly jay-dispersed) than for beechnuts (mostly nuthatch-dispersed). Long-distance dispersal of beechnuts (by jays) is determined by the presence of other preferred species (oaks) and their frequency of non-mast years. Seed location in different habitats strongly determines the contribution of different arboreal removers (including climbing rodents) and their removal speed, leading to a differential seed fate that will eventually affect tree regeneration. As nuthatches are sedentary birds, it is important to maintain old and dead trees where they can breed (crevices), forage (arthropods) and store seeds in order to favor beechnut dispersal and gene flow. By maintaining or favoring oak trees within beech stands we will ensure a wider guild of arboreal nut dispersers.

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Force sensors are used when interaction tasks are carried out by robots in general, and by climbing robots in particular. If the mechanics and electronics systems are contained inside the own robot, the robot becomes portable without external control. Commercial force sensors cannot be used due to limited space and weight. By selecting the links material with appropriate stiffness and placing strain gauges on the structure, the own robot flexibility can be used such as force sensor. Thus, forces applied on the robot tip can be measured without additional external devices. Only gauges and small internal electronic converters are necessary. This paper illustrates the proposed algorithm to achieve these measurements. Additionally, experimental results are presented.

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One of the most important design constraints of a climbing robot is its own weight. When links or legs are used as a locomotion system they tend to be composed of special lightweight materials, or four-bars-linkage mechanisms are designed to reduce the weight with small rigidity looses. In these cases, flexibility appears and undesirable effects, such as dynamics vibrations, must be avoided at least when the robot moves at low speeds. The knowledge of the real tip position requires the computation of its compliance or stiffness matrix and the external forces applied to the structure. Gravitational forces can be estimated, but external tip forces need to be measured. This paper proposes a strain gauge system which achieves the following tasks: (i) measurement of the external tip forces, and (ii) estimation of the real tip position (including flexibility effects). The main advantages of the proposed system are: (a) the use of external force sensors is avoided, and (b) a substantial reduction of the robot weight is achieved in comparison with other external force measurement systems. The proposed method is applied to a real symmetric climbing robot and experimental results are presented.

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Electric-powered wheelchairs improve the mobility of people with physical disabilities, but the problem to deal with certain architectural barriers has not been resolved satisfactorily. In order to solve this problem, a stair-climbing mobility system (SCMS) was developed. This paper presents a practical dynamic control system that allows the SCMS to exhibit a successful climbing process when faced with typical architectural barriers such as curbs, ramps, or staircases. The implemented control system depicts high simplicity, computational efficiency, and the possibility of an easy implementation in a microprocessor-/microcontroller-based system. Finally, experiments are included to support theoretical results.

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En la literatura se ha descrito el perfil antropométrico y la respuesta psicofisiológica en escalada deportiva en roca, pero hasta la fecha, no se habían analizado las diferencias existentes entre sus principales modalidades. El objetivo de la presente tesis fue describir las características antropométricas del escalador de competición y comprobar la existencia de diferencias entre los participantes de distintas modalidades, así como analizar la respuesta psico-fisiológica durante la ejecución de un búlder y una vía, además de evaluar las diferencias entre su realización a vista o tras un ensayo. Para ello, efectuamos dos estudios diferentes: en el primero participaron voluntariamente 61 hombres y 18 mujeres, participantes en cuatro pruebas del circuito nacional de competición de escalada durante el año 2009, tres de ellas de la modalidad de dificultad a vista y una de búlder. Se realizaron mediciones antropométricas, prueba de fuerza de prensión manual antes y después de competir, y se cumplimentó un cuestionario donde se evaluaba la percepción del esfuerzo y la experiencia deportiva. En el segundo estudio, 23 escaladores, 15 hombres y 8 mujeres, divididos en tres grupos en función de su nivel de rendimiento, realizaron de manera voluntaria distintas pruebas durante tres días separados entre sí al menos 48 horas. El primer día rellenaron un cuestionario sobre su experiencia deportiva y nivel de rendimiento, fueron pesados, tallados y sometidos a un escáner de cuerpo completo en densitómetro con objeto de medir la composición corporal. El segundo día realizaron previo calentamiento, un búlder a vista y, tras un descanso de 15 minutos, escalaron una vía a vista acorde con su nivel. El tercer día, después de calentar y disponer de 20 minutos para ensayarlo, repitieron la escalada del búlder. Tras un descanso de 15 minutos y 20 minutos de ensayo, realizaron un segundo intento a la vía. Se registraron los valores en la respuesta cardiorrespiratoria, se obtuvieron muestras de lactato en sangre del lóbulo de la oreja y se realizaron pruebas de fuerza de prensión manual antes y después de la escalada. También se pasó un cuestionario para medir la ansiedad y autoconfianza así como el esfuerzo percibido. Los resultados no mostraron diferencias antropométricas significativas entre los participantes en competiciones de búlder y los que participaron en competiciones de escalada de dificultad a vista. Se dieron diferencias en la pérdida de fuerza antes y después de escalar entre dichos participantes. Las mujeres obtuvieron menor fuerza de prensión manual que los hombres pero la misma pérdida de fuerza entre el instante antes de competir y el posterior. La respuesta fisiológica durante la ejecución del búlder fue menor que la obtenida durante la ejecución de la vía. Hubo pérdida de fuerza de prensión manual entre el instante anterior y el posterior a ejecutar la vía, pero no al hacer el búlder. Sin embargo, no se dieron diferencias en la ansiedad y la autoestima provocada por ambas modalidades, por lo que deducimos que la ejecución de un búlder y una vía presentan una respuesta fisiológica distinta. Proponemos que la respuesta está relacionada, sobre todo, con las variables de ejecución, de tal manera que a mayor distancia y/o tiempo recorrido en la escalada, mayor será la contribución anaeróbica al esfuerzo y la fatiga manifestada como pérdida de fuerza que, en el caso del búlder, fue mínima o inexistente. En el segundo intento, tras un ensayo de 20 minutos en el búlder, se consiguió mejorar el rendimiento respecto al primer intento, que se manifestó con un aumento en la distancia recorrida. Sin embargo, en la vía no se dieron diferencias entre ambos intentos, ni en la ejecución, ni en la respuesta fisiológica, ni en la ansiedad, ni siquiera en la fuerza de prensión manual. ABSTRACT It has been described in the literature the anthropometric profile and psychophysiological response in rock climbing, but so far not been analyzed differences between its main modalities. The aim of this thesis was to describe the anthropometric characteristics of the climber competitor and check for differences between participants of different modalities and to analyze the psycho-physiological response during the execution of a boulder and a route also to assess differences between on sight and redpoint attempts. We made two different studies: in the first 61 men and 18 women who attended four competitions of national climbing circuit in 2009, three of them on-sight difficulty competitions and a boulder competition participated voluntarily. Anthropometric measurements, a hand grip strength test before and after competing were registered for each climber, and a questionnaire which assessed perception of effort and the climbing experience was fulfilled. In the second study, various tests were conducted on 23 volunteer climbers, 15 men and 8 women, during three days separated for, at least, 48 hours of resting, divided into three groups according to their performance. The first day, climbers completed a questionnaire on their experience and performance level. It was recorded weight, height and they underwent a full body scan densitometer in order to measure body composition. The second day, after previous warming-up, they climbed a boulder on sight and, after a break of 15 minutes, climbed a route on-sight according to their level. The third day, after warming-up and have 20 minutes to try it, they repeated the bouldering climbing. After a break of 15 minutes and 20 minutes of essaying, they made a second attempt at the route. Values in the cardiorespiratory response were recorded, blood lactate samples were obtained from earlobe, and hand grip strength was tested before and after the climb. They also filled a questionnaire to measure anxiety and self-confidence and perceived exertion. The results showed no significant anthropometric differences between participants in bouldering competitions and participants in competitions on-sight difficulty climbing. There were found differences in strength loss before and after climbing between those participants. Women had less hand grip strength than men but the same loss of strength between the records carried out before and after competing. The physiological response recorded for boulder climbing was lower than the obtained for the route. There was loss of hand grip strength between the time before and after running the route but not for bouldering. However, there were no differences in anxiety and self-esteem caused by both modalities, so we conclude that the implementation of a boulder and a route have different physiological responses. We think that this response is mainly related to performance variables, as a greater distance and/or travel time on the climb, the higher the anaerobic contribution to the effort and fatigue as manifested by loss of strength in the case of the boulder was minimal or nonexistent. In the second attempt after 20 minutes in the boulder better performance was achieved on the first attempt, which was manifested by an increment of climbing distance. However, there were the differences in the route between the two attempts, either in execution or in the physiological response, or anxiety, or even in hand grip strength.

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El autor de este proyecto es miembro reciente de la asociación SoloBoulder, dedicada a la modalidad de escalada boulder, noticias y actualidad, contenido multimedia, promoción de un equipo de escaladores y defensa de valores medioambientales en la montaña. El principal canal de distribución de contenidos es una página web existente previa a este proyecto. La asociación ha detectado una escasez y mala calidad de recursos en internet en cuanto a guías de zonas donde poder practicar el boulder. Tal circunstancia impulsa la iniciativa de este proyecto fin de carrera. El objetivo general es el desarrollo de una nueva aplicación que proporcione a los usuarios a nivel mundial una guía interactiva de boulder y otros puntos de interés, una red social que permita la creación cooperativa y orgánica de contenido, y servicios web para el consumo de la información desde otras plataformas u organizaciones. El nuevo software desarrollado es independiente de la página web de SoloBoulder previa. No obstante, ambas partes se integran bajo el mismo domino web y aspecto. La nueva aplicación ofrece a escaladores y turistas un servicio informativo e interactivo de calidad, con el que se espera aumentar el número de visitas en todo el sitio web y poder ampliar la difusión de valores medioambientales, diversificar las zonas de boulder y regular las masificadas, favorecer el deporte y brindar al escalador una oportunidad de autopromoción personal. Una gran motivación para el autor también es el proceso de investigación y formación en tecnologías, patrones arquitecturales de diseño y metodologías de trabajo adaptadas a las tendencias actuales en la ingeniería de software, con especial curiosidad hacia el mundo web. A este respecto podemos destacar: metodología de trabajo en proyectos, análisis de proyectos, arquitecturas de software, diseño de software, bases de datos, programación y buenas prácticas, seguridad, interfaz gráfica web, diseño gráfico, Web Performance Optimization, Search Engine Optimization, etc. En resumen, este proyecto constituye un aprendizaje y puesta en práctica de diversos conocimientos adquiridos durante la ejecución del mismo, así como afianzamiento de materias estudiadas en la carrera. Además, el producto desarrollado ofrece un servicio de calidad a los usuarios y favorece el deporte y la autopromoción del escalador. ABSTRACT. The author of this Project is recent member of the association SoloBoulder, dedicated to a rock climbing discipline called bouldering, news, multimedia content, promotion of a team of climbers and defense of environmental values in the mountain. The main content distribution channel is a web page existing previous to this project. The association has detected scarcity and bad quality of resources on the internet about guides of bouldering areas. This circumstance motivates the initiative of this project. The general objective is the development of a new application which provides a worldwide, interactive bouldering guide, including other points of interest, a social network which allows the cooperative and organic creation of content, and web services for consumption of information from other platforms or organizations. The new software developed is independent of the previous SoloBoulder web page. However, both parts are integrated under the same domain and appearance. The new application offers to climbers and tourists a quality informative and interactive service, with which we hope to increase the number of visits in the whole web site and be able to expand the dissemination of environmental values, diversify boulder areas and regulate the overcrowded ones, encourage sport and offer to the climber an opportunity of self-promotion. A strong motivation for the author is also the process of investigation and education in technologies, architectural design patterns and working methodologies adapted to the actual trends in software engineering, with special curiosity about the web world. In this regard we could highlight: project working methodologies, project analysis, software architectures, software design, data bases, programming and good practices, security, graphic web interface, graphic design, Web Performance Optimization, Search Engine Optimization, etc. To sum up, this project constitutes learning and practice of diverse knowledge acquired during its execution, as well as consolidation of subjects studied in the degree. In addition, the product developed offers a quality service to the users and favors the sport and the selfpromotion of the climber.