218 research outputs found

    Reconstruction of the second layer of Ag on Pt(111)

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    The reconstruction of an Ag monolayer on Ag/Pt(111) is analyzed theoretically, employing a vertically extended Frenkel-Kontorova model whose parameters are derived from density functional theory. Energy minimization is carried out using simulated quantum annealing techniques. Our results are compatible with the STM experiments, where a striped pattern is initially found which transforms into a triangular reconstruction upon annealing. In our model we recognize the first structure as a metastable state, while the second one is the true energy minimum

    Robobo SmartCity: An Autonomous Driving Model for Computational Intelligence Learning through Educational Robotics

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    © 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[Abstract]: This paper presents the Robobo SmartCity model, an educational resource to introduce students in Computational Intelligence (CI) topics using educational robotics as the core learning technology. Robobo SmartCity allows educators to train learners in Artificial Intelligence (AI) fundamentals from a feasible and practical perspective, following the recommendations of digital education plans to introduce AI at all educational levels. This resource is based on the Robobo educational robot and an autonomous driving setup. It is made up of a city mockup, simulation models, and programming libraries adapted to the students' skill level. In it, students can be trained in CI topics that support robot autonomy, as computer vision, machine learning, or human-robot interaction, while developing solutions in the motivating and challenging scope of autonomous driving. The main details of this open resource are provided with a set of possible challenges to be faced in it. They are organized in terms of the educational level and students’ skills. The resource has been mainly tested with secondary and high school students, obtaining successful learning outcomes, presented here to inspire other teachers in taking advantage of this learning technology in their classes.Xunta de Galicia; ED431G 2019/01This work has been partially funded by the Erasmus+ Programme of the European Union through grant number 2019-1-ES01-KA201-065742, and the Centro de Investigación de Galicia "CITIC", funded by Xunta de Galicia and the European Union (European Regional Development Fund- Galicia 2014-2020 Program), by grant ED431G 2019/01. In addition, the “Programa de ayudas a la etapa predoctoral” from Xunta de Galicia (Consellería de Cultura, Educación y Universidad) supported this work through Sara Guerreiro’s grant

    Maximum-likelihood estimation of specific differential phase and attenuation in rain

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    Precise estimation of propagation parameters in precipitation media is of interest to improve the performance of communications systems and in remote sensing applications. In this paper, we present maximum-likelihood estimators of specific attenuation and specific differential phase in rain. The model used for obtaining the cited estimators assumes coherent propagation, reflection symmetry of the medium, and Gaussian statistics of the scattering matrix measurements. No assumptions about the microphysical properties of the medium are needed. The performance of the estimators is evaluated through simulated data. Results show negligible estimators bias and variances close to Cramer–Rao bounds

    Is there a tensionless Kardar-Parisi-Zhang universality class above one dimension? An Ising model approach

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    The Kardar-Parisi-Zhang (KPZ) equation is a paradigm of generic scale invariance, for which it represents a conspicuous universality class. Recently, the tensionless case of this equation has been shown to provide a different universality class by itself. This class describes the -- intrinsically anomalous -- scaling of one-dimensional (1D) fronts for several physical systems that feature ballistic dynamics. In this work, we show that the evolution of certain 1D fronts defined for a 2D Ising system also belongs to the tensionless KPZ universality class. Nevertheless, the Ising fronts exhibit multiscaling, at variance with the continuous equation. The discrete nature of these fronts provides an alternative approach to assess the dynamics for the 2D front case (for a 3D Ising system), since the direct integration of the tensionless KPZ equation blows up in this case. In spite of the agreement between the 1D scaling of the Ising fronts and the tensionless KPZ equation, the fluctuation statistics in 1D and the full behavior in 2D are strongly conditioned by boundary effects.Comment: 9 pages, 9 figure

    The teaching of spanish lexicography at university: a necessary renewal

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    El desarrollo tecnológico en el procesamiento lingüístico, el acceso preferente desde dispositivos móviles y las necesidades de los usuarios están trazando un panorama insólito en el ámbito de la lexicografía, que afecta a la docencia universitaria de la disciplina. El análisis de las respuestas de los estudiantes de la asignatura Lengua española 2 a un cuestionario anónimo sobre sus prácticas en el uso de los diccionarios —Facultad de Filología de la U. de Santiago de Compostela, curso 2015-2016— permite la reflexión docente, que apunta, como conclusión, a algunos cambios en el programa de la asignatura: la incorporación de los recursos bilingües en el temario, la inclusión de información sobre sinónimos y antónimos en español, esencial para las tareas de producción, y la asignación de un papel relevante a los recursos disponibles en línea, destinado a plantear cómo valorarlos y cómo obtener el mejor provecho de ellos.The technological development of linguistic processing, the preferential access from mobile devices and the needs of users are shaping an unusual panorama in the field of lexicography, which affects the university teaching of the discipline. The analysis of students' responses to an anonymous questionnaire about their practices in the use of dictionaries, carried out in the subject Lengua española 2, —Faculty of Philology of the University of Santiago de Compostela, academic year 2015-2016— allows the teaching reflection, which points, as a conclusion, to some changes in the syllabus of the subject: the incorporation of bilingual resources in the list of topics, the inclusion of information on synonyms and antonyms in Spanish, essential for production tasks, and the allocation of a relevant role to resources available online, aimed at considering how to value them and how to get the best out of them

    AI curriculum for european high schools: an embedded intelligence approach

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    Financiado para publicación en acceso aberto: Universidade da Coruña/CISUGXunta de Galicia ; ED431G 2019/0

    Breeding for culinary and nutritional quality of common bean (Phaseolus vulgaris L.) in intercropping systems with maize (Zea mays L.)

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    Common bean (Phaseolus vulgaris L.) is widely intercropped with maize (Zea mays L.) in the North of Spain. Breeding beans for multiple cropping systems is important for the development of a productive and sustainable agriculture, and is mainly oriented to minimize intercrop competition and to stabilize complementarity with maize. Most agricultural research on intercropping to date has focused on the agronomic and overall yield effects of the different species, but characters related with socio-economic and food quality aspects are also important. The effect of intercropping beans with maize on food seed quality traits was studied for thirty-five bush bean varieties under different environments in Galicia (Northwestern Spain). Parameters determining Asturian (Northern Spain) white bean commercial and culinary quality have also been evaluated in fifteen accessions. There are significant differences between varieties in the selected cropping systems (sole crop, intercrop with field maize and intercrop with sweet maize) for dry and soaked seed weight, coat proportion, crude protein, crude fat and moisture. Different white bean accessions have been chosen according to their culinary quality. Under these environmental conditions it appears that intercropping systems with sweet maize give higher returns than sole cropping system. It is also suggested that the culinary and nutritional quality potential of some white bean accessions could be the base material in a breeding programme the objectives of which are to develop varieties giving seeds with high food quality

    Pion gas viscosity at low temperature and density

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    By using Chiral Perturbation Theory and the Uehling-Uhlenbeck equation we compute the viscosity of a pion gas, in the low temperature and low density regime, in terms of the temperature, and the pion fugacity. The viscosity turns out to be proportional to the squared root of the temperature over the pion mass. Next to leading corrections are proportional to the temperature over the pion mass to the 3/2.Comment: 15 pages, 4 figures. RevTeX

    Physical consequences of P\neqNP and the DMRG-annealing conjecture

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    Computational complexity theory contains a corpus of theorems and conjectures regarding the time a Turing machine will need to solve certain types of problems as a function of the input size. Nature {\em need not} be a Turing machine and, thus, these theorems do not apply directly to it. But {\em classical simulations} of physical processes are programs running on Turing machines and, as such, are subject to them. In this work, computational complexity theory is applied to classical simulations of systems performing an adiabatic quantum computation (AQC), based on an annealed extension of the density matrix renormalization group (DMRG). We conjecture that the computational time required for those classical simulations is controlled solely by the {\em maximal entanglement} found during the process. Thus, lower bounds on the growth of entanglement with the system size can be provided. In some cases, quantum phase transitions can be predicted to take place in certain inhomogeneous systems. Concretely, physical conclusions are drawn from the assumption that the complexity classes {\bf P} and {\bf NP} differ. As a by-product, an alternative measure of entanglement is proposed which, via Chebyshev's inequality, allows to establish strict bounds on the required computational time.Comment: Accepted for publication in JSTA
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