963 research outputs found

    Adaptive Interaction of Persistent Robots to User Temporal Preferences

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    Abstract. We look at the problem of enabling a mobile service robot to autonomously adapt to user preferences over repeated interactions in a long-term time frame, where the user provides feedback on every interaction in the form of a rating. We assume that the robot has a discrete and finite set of interaction options from which it has to choose one at every encounter with a given user. We first present three models of users which span the spectrum of possible preference profiles and their dynamics, incorporating aspects such as boredom and taste for change or surprise. Second, given the model to which the user belongs to, we present a learning algorithm which is able to successfully learn the model parameters. We show the applicability of our framework to personalizing light animations on our mobile service robot, CoBot.

    High sensitivity X-ray phase contrast imaging by laboratory grating-based interferometry at high Talbot order geometry

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    X-ray phase contrast imaging is a powerful analysis technique for materials science and biomedicine. Here, we report on laboratory grating-based X-ray interferometry employing a microfocus X-ray source and a high Talbot order (35th) asymmetric geometry to achieve high angular sensitivity and high spatial resolution X-ray phase contrast imaging in a compact system (total length <1 m). The detection of very small refractive angles (∼50 nrad) at an interferometer design energy of 19 keV was enabled by combining small period X-ray gratings (1.0, 1.5 and 3.0 µm) and a single-photon counting X-ray detector (75 µm pixel size). The performance of the X-ray interferometer was fully characterized in terms of angular sensitivity and spatial resolution. Finally, the potential of laboratory X-ray phase contrast for biomedical imaging is demonstrated by obtaining high resolution X-ray phase tomographies of a mouse embryo embedded in solid paraffin and a formalin-fixed full-thickness sample of human left ventricle in water with a spatial resolution of 21.5 µm

    ¿La combinación de clones posee alguna ventaja sobre los sistemas monoclonales?

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    Forest plantations with different trees and purposes were traditionally developed with seminal seedlings. Actually, the most important planted tree species can be propagated by vegetative methods, so clonal silviculture has high possibilities to grow. Salicaceae plantations are established by cuttings of genetically improved trees. This determines that poplars and willows are produced under clonal silviculture systems. Furthermore, at the region of Paraná River Delta, stands are monoclonal and Populus deltoides ‘Australiano 129/60’ is the most widespread clone. These forest systems are unstable and there is a productive risk associated to emergence of pests, diseases and extreme climatic conditions. Thus, monoclonal silviculture model has some ecological and productive disadvantages. Reducing genetic diversity could threat the aims of the forest plantations and it is important to consider aspects related to biodiversity when plantations are planned. Clone combination in the same stand can be useful to increase genetic diversity, because tree species are highly diverse at both inter and intraspecific level. Mixed clonal plantations can favor to decrease the impact of productive activities on the environment, spatially distribute soil nutrient demand, increase genetic diversity and enhance stand yields.The aim of this review is to analyze previous experiences in clonal silviculture and plantation in mixed stands as a framework to propose silvicultural alternatives for Salicaceae production in Paraná River Delta, Argentina.Las plantaciones forestales han sido tradicionalmente desarrolladas a partir de material de propagación de origen seminal. Sin embargo, las principales especies plantadas en el mundo se pueden propagar vegetativamente, por lo que las posibilidades para el desarrollo de la silvicultura clonal son crecientes. El cultivo de Salicáceas se realiza con estacas o guías, por lo que las plantaciones son 100% producidas bajo un esquema de silvicultura clonal. Además, en el Delta del Río Paraná los rodales se instalan como bloques monoclonales y el clon Populus deltoides ‘Australiano 129/60’ es el más difundido, definiendo una matriz productiva con una estrecha diversidad genética. Esto determina que el sistema sea menos estable y trae aparejado un riesgo productivo ante la aparición de condiciones de estrés biótico o abiótico. En consecuencia, el modelo de silvicultura monoclonal presenta algunas desventajas no solo desde el punto de vista ecológico, sino también productivo. A partir de la posibilidad que brindan las especies forestales, que presentan una gran variabilidad tanto intra como interespecífica, es posible pensar en combinación de clones para aumentar la diversidad genética de las plantaciones. Las plantaciones clonales mixtas pueden favorecer a la disminución de los impactos de las actividades productivas en el ambiente, distribuir espacialmente la demanda de nutrientes del suelo, aumentar la diversidad genética y mejorar los índices de rendimiento del rodal. El objetivo de esta revisión es analizar los antecedentes de silvicultura clonal y plantaciones mixtas como base para la propuesta de alternativas silviculturales para las Salicáceas del Delta del Paraná

    ¿La combinación de clones posee alguna ventaja sobre los sistemas monoclonales? Posibles alternativas silviculturales para las Salicáceas, a partir de la revisión de experiencias previas

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    Las plantaciones forestales han sido tradicionalmente desarrolladas a partir de material de propagación de origen seminal. Sin embargo, las principales especies plantadas en el mundo se pueden propagar vegetativamente, por lo que las posibilidades para el desarrollo de la silvicultura clonal son crecientes. El cultivo de Salicáceas se realiza con estacas o guías, por lo que las plantaciones son 100% producidas bajo un esquema de silvicultura clonal. Además, en el Delta del Río Paraná los rodales se instalan como bloques monoclonales y el clon Populus deltoides ?Australiano 129/60? es el más difundido, definiendo una matriz productiva con una estrecha diversidad genética. Esto determina que el sistema sea menos estable y trae aparejado un riesgo productivo ante la aparición de condiciones de estrés biótico o abiótico. En consecuencia, el modelo de silvicultura monoclonal presenta algunas desventajas no solo desde el punto de vista ecológico, sino también productivo. A partir de la posibilidad que brindan las especies forestales, que presentan una gran variabilidad tanto intra como interespecífica, es posible pensar en combinación de clones para aumentar la diversidad genética de las plantaciones. Las plantaciones clonales mixtas pueden favorecer a la disminución de los impactos de las actividades productivas en el ambiente, distribuir espacialmente la demanda de nutrientes del suelo, aumentar la diversidad genética y mejorar los índices de rendimiento del rodal. El objetivo de esta revisión es analizar los antecedentes de silvicultura clonal y plantaciones mixtas como base para la propuesta de alternativas silviculturales para las Salicáceas del Delta del Paraná.Forest plantations with different trees and purposes were traditionally developed with seminal seedlings. Actually, the most important planted tree species can be propagated by vegetative methods, so clonal silviculture has high possibilities to grow. Salicaceae plantations are established by cuttings of genetically improved trees. This determines that poplars and willows are produced under clonal silviculture systems. Furthermore, at the region of Paraná River Delta, stands are monoclonal and Populus deltoides ‘Australiano 129/60’ is the most widespread clone. These forest systems are unstable and there is a productive risk associated to emergence of pests, diseases and extreme climatic conditions. Thus, monoclonal silviculture model has some ecological and productive disadvantages. Reducing genetic diversity could threat the aims of the forest plantations and it is important to consider aspects related to biodiversity when plantations are planned. Clone combination in the same stand can be useful to increase genetic diversity, because tree species are highly diverse at both inter and intraspecific level. Mixed clonal plantations can favor to decrease the impact of productive activities on the environment, spatially distribute soil nutrient demand, increase genetic diversity and enhance stand yields.The aim of this review is to analyze previous experiences in clonal silviculture and plantation in mixed stands as a framework to propose silvicultural alternatives for Salicaceae production in Paraná River Delta, Argentina.Fil: Bonnin, Sebastián Martin. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Delta del Paraná; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Faustino, Laura I.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Alvarez, Javier A.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Graciano, Corina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; Argentin

    Professions, governance and citizenship through the global looking glass

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    The state-professions relationship and the role of professionalism as facilitator of public sector services are key issues of the professions studies. This makes the study of professions an important source of understanding how to create a “better world,” with more efficient public sectors and accessible services for all citizens. Currently, the relationships between professions and the state face a number of fundamental transformations involving different governance reforms, stakeholders, and professional groups. First, state regulation expands towards “governance” with plural actors and market logics; second, globalization and new economies add new forms of “state” and “citizenship”; and third, austerity politics curb prospering markets and public funding for professional services.info:eu-repo/semantics/publishedVersio
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