1,966 research outputs found

    Radiative flux measurements in the stratosphere

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    The objective is to determine how the stratospheric tropospheric exchange of water vapor is affected by the interaction of solar (visible) and planetary (infrared) radiation with tropical cumulonimbus anvils. This research involves field measurements from the ER-2 aircraft as well as radiative transfer modelling to determine heating and cooling rates and profiles that directly affect the exchange between the troposphere and the stratosphere

    On Neuromechanical Approaches for the Study of Biological Grasp and Manipulation

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    Biological and robotic grasp and manipulation are undeniably similar at the level of mechanical task performance. However, their underlying fundamental biological vs. engineering mechanisms are, by definition, dramatically different and can even be antithetical. Even our approach to each is diametrically opposite: inductive science for the study of biological systems vs. engineering synthesis for the design and construction of robotic systems. The past 20 years have seen several conceptual advances in both fields and the quest to unify them. Chief among them is the reluctant recognition that their underlying fundamental mechanisms may actually share limited common ground, while exhibiting many fundamental differences. This recognition is particularly liberating because it allows us to resolve and move beyond multiple paradoxes and contradictions that arose from the initial reasonable assumption of a large common ground. Here, we begin by introducing the perspective of neuromechanics, which emphasizes that real-world behavior emerges from the intimate interactions among the physical structure of the system, the mechanical requirements of a task, the feasible neural control actions to produce it, and the ability of the neuromuscular system to adapt through interactions with the environment. This allows us to articulate a succinct overview of a few salient conceptual paradoxes and contradictions regarding under-determined vs. over-determined mechanics, under- vs. over-actuated control, prescribed vs. emergent function, learning vs. implementation vs. adaptation, prescriptive vs. descriptive synergies, and optimal vs. habitual performance. We conclude by presenting open questions and suggesting directions for future research. We hope this frank assessment of the state-of-the-art will encourage and guide these communities to continue to interact and make progress in these important areas

    A physical model suggests that hip-localized balance sense in birds improves state estimation in perching: implications for bipedal robots

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    In addition to a vestibular system, birds uniquely have a balance-sensing organ within the pelvis, called the lumbosacral organ (LSO). The LSO is well developed in terrestrial birds, possibly to facilitate balance control in perching and terrestrial locomotion. No previous studies have quantified the functional benefits of the LSO for balance. We suggest two main benefits of hip-localized balance sense: reduced sensorimotor delay and improved estimation of foot-ground acceleration. We used system identification to test the hypothesis that hip-localized balance sense improves estimates of foot acceleration compared to a head-localized sense, due to closer proximity to the feet. We built a physical model of a standing guinea fowl perched on a platform, and used 3D accelerometers at the hip and head to replicate balance sense by the LSO and vestibular systems. The horizontal platform was attached to the end effector of a 6 DOF robotic arm, allowing us to apply perturbations to the platform analogous to motions of a compliant branch. We also compared state estimation between models with low and high neck stiffness. Cross-correlations revealed that foot-to-hip sensing delays were shorter than foot-to-head, as expected. We used multi-variable output error state-space (MOESP) system identification to estimate foot-ground acceleration as a function of hip- and head-localized sensing, individually and combined. Hip-localized sensors alone provided the best state estimates, which were not improved when fused with head-localized sensors. However, estimates from head-localized sensors improved with higher neck stiffness. Our findings support the hypothesis that hip-localized balance sense improves the speed and accuracy of foot state estimation compared to head-localized sense. The findings also suggest a role of neck muscles for active sensing for balance control: increased neck stiffness through muscle co-contraction can improve the utility of vestibular signals. Our engineering approach provides, to our knowledge, the first quantitative evidence for functional benefits of the LSO balance sense in birds. The findings support notions of control modularity in birds, with preferential vestibular sense for head stability and gaze, and LSO for body balance control,respectively. The findings also suggest advantages for distributed and active sensing for agile locomotion in compliant bipedal robots

    Complementary music therapy for cancer patients in at-home palliative care and their caregivers: protocol for a multicentre randomised controlled trial

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    Background Patients with advanced cancer, receiving at-home palliative care, are subject to numerous symptoms that are changeable and often require attention, a stressful situation that also impacts on the family caregiver. It has been suggested that music therapy may benefit both the patient and the caregiver. We propose a study to analyse the efficacy and cost utility of a music intervention programme, applied as complementary therapy, for cancer patients in palliative care and for their at-home caregivers, compared to usual treatment. Method A randomised, double-blind, multicentre clinical trial will be performed in cancer patients in at-home palliative care and their family caregivers. The study population will include two samples of 40 patients and two samples of 41 caregivers. Participants will be randomly assigned either to the intervention group or to the control group. The intervention group will receive a seven-day programme including music sessions, while the control group will receive seven sessions of (spoken word) therapeutic education. In this study, the primary outcome measure is the assessment of patients' symptoms, according to the Edmonton Symptom Assessment System, and of the overload experienced by family caregivers, measured by the Caregiver Strain Index. The secondary outcomes considered will be the participants' health-related quality of life, their satisfaction with the intervention, and an economic valuation. Discussion This study is expected to enhance our understanding of the efficacy and cost-utility of music therapy for cancer patients in palliative care and for their family caregivers. The results of this project are expected to be applicable and transferrable to usual clinical practice for patients in home palliative care and for their caregivers. The approach described can be incorporated as an additional therapeutic resource within comprehensive palliative care. To our knowledge, no previous high quality studies, based on a double-blind clinical trial, have been undertaken to evaluate the cost-effectiveness of music therapy. The cost-effectiveness of the project will provide information to support decision making, thereby improving the management of health resources and their use within the health system

    L'Escola Normal de Magisteri Primari de Barcelona: 1939, anno zero

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    La universidad fascista y la universidad franquista en perspectiva comparada.

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    La universidad fue un importante instrumento de control y legitimación ideológica en los regímenes fascistas. Aquí se propone una comparación entre las universidades de la Italia fascista y la España de la primera mitad de la dictadura franquista. Partiendo de la situación de la universidad liberal, se analizan los cambios que en ambos países tuvieron lugar en las estructuras universitarias y se muestra cómo al final del proceso las similitudes en la organización administrativa y el gobierno de las universidades, la situación del profesorado y el papel de los estudiantes fueron notablemente superiores a las diferencias, que también se dieron.The university has been an important instrument of control and of ideological legitimation in fascist regimes. The author compares in this article the Italian universities of the Fascist period with those in Spain during the first half of Francos Dictatorship. Starting from the situation at the liberal university, the author analyzes the changes that took place in the structures of the universities of both countries and shows that, at the end of the process, the similarities considerably outnumbered the differences, not only in terms of the administrative organization and management of the two university systems, but also in relation to the situation of the academic staff and to the role played by the students.Publicad

    Els camins de la dissidència. Dionisio Ridruejo i el llarg viatge cap a la democràcia

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    Dionisio Ridruejo va ser un dels principals dirigents falangistes durant la Guerra Civil i la immediata postguerra. Des de 1942 va iniciar una evolució política que, sense suposar l’abandonament de les seves conviccions feixistes, el va allunyar del règim de Franco. La ruptura definitiva i la seva adscripció a posicions democràtiques no es va produir, tanmateix, fins a 1956. Aquest treball es dedica a explorar la trajectòria de Ridruejo i a proposar les claus interpretatives de la seva evolució ideològica i política.Dionisio Ridruejo was one of the main falangist leaders during, and immediately after, the Spanish civil war. From 1942, he went through a political evolution that, without changing his fascist political convictions, drew him apart from Franco's regime. However, the definitive break-up and his ascription to a more democratic position did not take place until 1956. This piece of work is aimed at exploring Ridruejo's trajectory and proposes the interpretive keys of his ideological and political evolution

    Hierarchical clustered register file organization for VLIW processors

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    Technology projections indicate that wire delays will become one of the biggest constraints in future microprocessor designs. To avoid long wire delays and therefore long cycle times, processor cores must be partitioned into components so that most of the communication is done locally. In this paper, we propose a novel register file organization for VLIW cores that combines clustering with a hierarchical register file organization. Functional units are organized in clusters, each one with a local first level register file. The local register files are connected to a global second level register file, which provides access to memory. All intercluster communications are done through the second level register file. This paper also proposes MIRS-HC, a novel modulo scheduling technique that simultaneously performs instruction scheduling, cluster selection, inserts communication operations, performs register allocation and spill insertion for the proposed organization. The results show that although more cycles are required to execute applications, the execution time is reduced due to a shorter cycle time. In addition, the combination of clustering and hierarchy provides a larger design exploration space that trades-off performance and technology requirements.Peer ReviewedPostprint (published version
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