3,269 research outputs found
THROES: a caTalogue of HeRschel Observations of Evolved Stars. I. PACS range spectroscopy
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
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
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
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
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
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
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
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
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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