3,269 research outputs found

    THROES: a caTalogue of HeRschel Observations of Evolved Stars. I. PACS range spectroscopy

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    This is the first of a series of papers presenting the THROES (A caTalogue of HeRschel Observations of Evolved Stars) project, intended to provide a comprehensive overview of the spectroscopic results obtained in the far-infrared (55-670 microns) with the Her- schel space observatory on low-to-intermediate mass evolved stars in our Galaxy. Here we introduce the catalogue of interactively reprocessed PACS (Photoconductor Array Camera and Spectrometer) spectra covering the 55-200 microns range for 114 stars in this category for which PACS range spectroscopic data is available in the Herschel Science Archive (HSA). Our sample includes objects spanning a range of evolutionary stages, from the asymptotic giant branch to the planetary nebula phase, displaying a wide variety of chemical and physical properties. The THROES/PACS catalogue is accessible via a dedicated web-based inter- face (https://throes.cab.inta-csic.es/) and includes not only the science-ready Herschel spectroscopic data for each source, but also complementary photometric and spectroscopic data from other infrared observatories, namely IRAS (Infrared Astronomical Satellite), ISO (Infrared Space Observatory) or AKARI, at overlapping wavelengths. Our goal is to create a legacy-value Herschel dataset that can be used by the scientific community in the future to deepen our knowledge and understanding of these latest stages of the evolution of low-to-intermediate mass stars.Comment: 38 page

    Measurement-based adaptation protocol with quantum reinforcement learning in a Rigetti quantum computer

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    We present an experimental realization of a measurement-based adaptation protocol with quantum reinforcement learning in a Rigetti cloud quantum computer. The experiment in this few-qubit superconducting chip faithfully reproduces the theoretical proposal, setting the first steps towards a semiautonomous quantum agent. This experiment paves the way towards quantum reinforcement learning with superconducting circuits

    Design issues for the VLSI implementation of universal approximator fuzzy systems

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    Comunicación presentada al "CSCC'99" celebrado en Atenas en Julio de 1999.Several VLSI realizations of fuzzy systems have been proposed in the literature in the recent years. They employ analog or digital circuitry, offering more or less programmability, implementing different inference methods, with different types of membership functions as well as different antecedents’ connectives. This paper centers this wide design space by fixing several parameters that allow efficient VLSI implementations of programmable fuzzy systems featuring first, second and third order accurate approximation. Hardware requirements are discussed and compared from the point of view of approximation capability or precision, thus attempting to a formalization that has never been applied before to the field of fuzzy hardware.This work has been partially supported by the Spanish CICYT Project TIC98-0869.Peer reviewe

    Controladores difusos adaptativos como módulos de propiedad intelectual para FPGAs

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    La continua demanda por parte del mercado microelectrónico de aplicaciones novedosas, con elevados niveles de complejidad y tiempos de desarrollo cortos ha motivado el impulso de las técnicas de diseño basadas en el concepto de “reusabilidad” y el desarrollo de elementos de sistemas como módulos de propiedad intelectual o módulos IP. En esta comunicación se describe la implementación de controladores difusos como módulos IP para FPGAs. Los controladores operan como periféricos conectables al bus OPB para los procesadores disponibles en las FPGAs de Xilinx. El empleo de las memorias internas de las FPGAs para almacenar las bases de conocimiento permite definir o ajustar la funcionalidad en tiempo de operación.Ministerio de Educaión y Ciencia TEC2005-04359/MI

    Prototipado rápido de sistemas de procesado de vídeo basados en el VFBC de Xilinx

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    El presente trabajo desarrolla módulos hardware para el prototipado rápido de sistemas de procesado de vídeo basados en el controlador de memoria para fotogramas de vídeo (VFBC) de Xilinx. Esta implementación permite el almacenamiento de los fotogramas en memoria externa al dispositivo programable, así como su correcto manejo para el diseño de sistemas de procesado espacio-temporales utilizando el flujo de diseño basado en modelos de Xilinx System Generator. Los módulos hardware son los encargados de la configuración y control de las interfaces de escritura y lectura del VFBC, además de la manipulación de las señales de sincronismo de vídeo para la interconexión de periféricos de entrada y salida. El artículo incluye además la descripción de los módulos elaborados así como el análisis de los resultados del empleo de los mismos en el desarrollo de un demostrador de procesado temporal de vídeo utilizando un detector de movimiento simple sobre una placa Spartan-6 SP605 Evaluation Platform.This paper develops hardware modules for rapid prototyping of video processing systems based on the Xilinx video frame buffer controller (VFBC). This implementation allows the storage of video frames in memory external to the programmable device, as well as its proper handle for designing spatio-temporal processing systems using the Xilinx System Generator model-based design flow. The hardware modules are responsible for the configuration and control of writing and reading VFBC interfaces, as well as the manipulation of video synchronization signals for interconnecting input and output peripherals. The article also include the description of the elaborated modules and the analysis of the results of its use for the development of a temporal video processing demonstrator using a simple motion detector on a Spartan-6 SP605 Evaluation Platform board.Agencia Española de Cooperación Internacional para el Desarrollo (AECID) PCI D/024124/09, PCI D/030769/10, PCI A1/039607/1

    Acquisition of financial management skills in the new framework for adaptation to the EHEA. Póster

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    One of the main consequences of adapting to the European Higher Education Area (EHEA) is the replacement of traditional teaching methods, based almost entirely on the lecture, with new methodologies where active participation on the part of the students is a key part of the teaching-learning process. It is, therefore, of interest to offer empirical evidence showing that the new teaching methods employed really do serve to improve the results of the students in the acquisition of skills. The aim of this paper is, therefore, to assess the results obtained from bringing in the new EHEA, compared to those obtained under the traditional teaching system. With the above aim in mind, we analysed the results from the two existing groups of students studying Financial Management I of the Degree in Business Administration and Management (academic year 2009-10) at the Faculty of Economics and Business of the University of Murcia. The first group comprised students who had followed the course under the traditional lecture-based teaching system. The second group was made up of students taking part in the innovation project being run by the Faculty of Economics and Business. EHEA teaching methodologies and materials have been employed in the second group. Besides the lecture and the practical class, the following teaching methodologies have been employed: problem-based learning, workshops on problems, group tutorials, group work and participative models. The first group was assessed purely on the basis of an end of semester examination, while in the case of the second group, the final examination counted for 60% of the mark, 30% corresponded to individual work and group practical work and 10% to participation in class and responses to questions posed by the teacher. It should be highlighted that the final examination was the same for both groups, so the comparison o results is free of bias in that aspect. The results show that higher percentage of passes in the group with innovative teaching – 93.75% versus 48.19% in the lecture-based class group. The average grade was also higher – 7.08 over 10 versus 4.52 over 10. These differences are significant (t statistic 6.382 for the means difference test). In order to rule out the possibility of these better results being due to the assessment awarded for the non similar parts of the examination, a comparison was also made of the marks obtained exclusively in the examination common to both groups. While the number of passes (75%) and the average mark of the group in the innovative method (6 over 10) fall, the results remain significantly better than those of the lecture-based classes group (t statistic for the difference in mean marks was 2.485).Campus Mare Nostrum, Universidad Politécnica de Cartagena, Universidad de Murcia, Región de Murci

    FPGA implementation of embedded fuzzy controllers for robotic applications

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    Fuzzy-logic-based inference techniques provide efficient solutions for control problems in classical and emerging applications. However, the lack of specific design tools and systematic approaches for hardware implementation of complex fuzzy controllers limits the applicability of these techniques in modern microelectronics products. This paper discusses a design strategy that eases the implementation of embedded fuzzy controllers as systems on programmable chips. The development of the controllers is carried out by means of a reconfigurable platform based on field-programmable gate arrays. This platform combines specific hardware to implement fuzzy inference modules with a general-purpose processor, thus allowing the realization of hybrid hardware/soffivare solutions. As happens to the components of the processing system, the specific fuzzy elements are conceived as configurable intellectual property modules in order to accelerate the controller design cycle. The design methodology and tool chain presented in this paper have been applied to the realization of a control system for solving the navigation tasks of an autonomous vehicle

    Medidas multi-influencia como medio para caracterizar la firma global de un buque y proteger el entorno marino

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    The overall signature of a vessel comprises acoustic, magnetic, electric-field, pressure, and seismic radiations. Over the past years, the international community’s efforts have mainly centered on reducing the acoustic influence with the dual aim of decreasing the vessel’s detectability and reducing the levels of acoustic pollution generated in the marine environment. Nowadays, the need to act not only on the acoustic radiation but against the overall set of the vessel’s radiations is becoming increasingly clear, both in the military and the civilian fields, based on aspects like vessel stealthiness, security of harbor and critical infrastructures, and environmental protection. As a key element to achieve this goal, it is greatly important to have at our disposal highly modular and adaptable measurement systems covering the overall set of the vessel’s radiations, with a high capacity of data transmission to base centers to have the capacity to make measurements in all kinds of marine environments.La firma global de un buque está compuesta por radiaciones: acústica, magnética, de campo eléctrico, de presión y sísmica. A lo largo de los últimos años, los esfuerzos de la comunidad internacional se han centrado principalmente en reducir la influencia acústica, con el doble objetivo de disminuir la detectabilidad del buque y reducir el nivel de contaminación acústica generada en el entorno marino. En la actualidad, se está constatando con claridad la necesidad de actuar no sólo sobre la radiación acústica, sino sobre el conjunto global de las radiaciones del buque, tanto en el ámbito militar como en el ámbito civil, basado en aspectos como: la discreción de los buques, la seguridad en puertos e infraestructuras críticas y la protección ambiental. Como elemento clave para alcanzar esta meta, es de gran importancia tener a nuestra disposición sistemas de medida adaptables y altamente modulares que cubran el conjunto total de las radiaciones de los buques, con alta capacidad de transmisión de datos a centros base, con el objeto de tener la capacidad de realizar medidas en toda clase de entornos marinos

    Pyranylidene/trifluoromethylbenzoic acid-based chromophores for dye-sensitized solar cells

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    The synthesis and photovoltaic study of five dyes based on 4H-pyranylidene moiety as donor moiety is reported. A thiophene unit conjugated with/without an ethynyl bond acts as the p-relay and benzoic acid as the anchor group with/without a trifluoromethyl group. Their electrochemical and optical properties are analyzed by using a joint experimental and theoretical approach. The presence of the trifluoromethyl group leads to an enhancement of the molar extinction coefficient, being slightly when a hexyl chain is introduced in the thiophene ring, but does not modify the oxidation potential. For the preparation of derived solar cells an antiaggregant is essential in all cases. The photovoltaic performance is sensitive to the structural modification of the dye: the CF3 group and the hexyl chain of the thiophene spacer were shown to improve the efficiency. The lack of a triple bond in the p-spacer involves a lower photovoltaic efficiency, and the trifluoromethyl group leads to a lower dye-load, but a decrease of the recombination processes. These results are in accordance with the electrochemistry impedance spectroscopy studies carried out. Moreover, the organic dyes have been also tested with a fluorescent lamp (indoor conditions), leading to an increase of the efficiency, reaching a 36% for the best dye. © 2022 The Author
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