Improving edge finite element assembly for geophysical electromagnetic modelling on shared-memory architectures

This work presents a set of node-level optimizations to perform the assembly of edge finite element matrices that arise in 3D geophysical electromagnetic modelling on shared-memory architectures. Firstly, we describe the traditional and sequential assembly approach. Secondly, we depict our vectorized and shared-memory strategy which does not require any low level instructions because it is based on an interpreted programming language, namely, Python. As a result, we obtained a simple parallel-vectorized algorithm whose runtime performance is considerably better than sequential version. The set of optimizations have been included to the work-flow of the Parallel Edge-based Tool for Geophysical Electromagnetic Modelling (PETGEM) which is developed as open-source at the Barcelona Supercomputing Center. Finally, we present numerical results for a set of tests in order to illustrate the performance of our strategy.This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 644202. The research leading to these results has received funding from the European Union's Horizon 2020 Programme (2014-2020) and from Brazilian Ministry of Science, Technology and Innovation through Rede Nacional de Pesquisa (RNP) under the HPC4E Project (www.hpc4e.eu), grant agreement No. 689772. Authors gratefully acknowledge the support from the Mexican National Council for Science and Technology (CONACYT). All numerical tests were performed on the MareNostrum supercomputer of the Barcelona Supercomputing Center - Centro Nacional de Supercomputación (www.bsc.es).Peer ReviewedPostprint (author's final draft

Intrinsic mechanism of phase locking in two-dimensional Josephson junction networks in presence of an external magnetic field

We present numerical simulations of the dynamics of two-dimensional Josephson junction arrays to study the mechanism of mutual phase locking. We show that in the presence of an external magnetic field two mechanisms are playing a role in phase locking: feedback through the external load and internal coupling between rows due to microwave currents induced by the field. We have found the parameter values (junction capacitance, cell loop inductance, impedance of the external load) for which the interplay of both these mechanisms leads to the in-phase solution. The case of unshunted arrays is discussed as well.Comment: 13 pages, incl. 6 ps figures, Subm. to Europhysics Letter

Can Crop Insurance Premiums Be Reliably Estimated?

This paper develops and applies a methodology to assess the accuracy of historical loss-cost rating procedures, similar to those used by the U.S. Department of Agriculture’s Risk Management Agency (RMA), versus alternative parametric premium estimation methods. It finds that the accuracy of loss-cost procedures leaves much to be desired, but can be markedly improved through the use of alternative methods and increased farm-level yield sample sizes. Evidence suggests that the high degree of inaccuracy in crop insurance premium estimations through historical loss-cost procedures identified in the paper might be a major factor behind the need for substantial government subsidies to keep the program solvent.agricultural subsidies, crop insurance premium estimation, loss-cost procedures, Risk Management Agency, Agricultural and Food Policy, Agricultural Finance, Farm Management, Risk and Uncertainty,

Congresso Internacional sobre Património Geológico e Mineiro.Livro de resumos

Congreso Internacional sobre Patrimonio Geológico e Miner

Description of hysteretic current-voltage characteristics of SNS junctions

Simplified model for current-voltage characteristics of weak links is suggested. It is based on an approach considering the multiple Andreev reflection in metallic Josephson junction. The model allows to calculate current-voltage characteristics of the superconductor - normal metal - superconductor junctions with different thicknesses of normal layer at different temperatures. A hysteretic peculiarity of $V(I)$ dependence is described as result of the negative differential resistance. The current-voltage characteristic of high-$T_c$ composite YBCO +BaPbO${_3}$ were computed.Comment: 9 pages, 5 figures, submited to Supercond. Sci. Technol, replased Fig.5 for more correct comparison with experimen

Nota sobre la composición mineralógica de unos piroxenos monoclínicos de Peñas de Haya (Guipúzcoa, Navarra)

Clinopyroxenes from Peñas de Haya (Guipúzcoa, Navarra) have been studied by X-ray single crystal diffraction. From chemical and crystal structure refinement it is shown that these pyroxenes are almost pure hedenbergite. The unitiell dimensions are: a = 9.867(3), b = 9.052(4), c = 5.253(0) A, p = 104.89(2)"

Actas del Primer Simposio sobre Arqueología Industrial: Conservación y recuperación del Patrimonio Minero-Metalúrgico en el Mundo hispánico. 49 Congreso Internacional de Americanistas, Quito, julio de 1997

Por la presente, queremos presentar la publicación correspondiente al PRIMER SIMPOSIO SOBRE ARQUEOLOGíA INDUSTRIAL: CONSERVACIÓN Y RECUPERACIÓN DEL PATRIMONIO MINERO-METALÚRGICO EN EL MUNDO HISPÁNICO. Este Simposio tuvo lugar durante el mes de julio de 1997, en la ciudad de Quito, con motivo de la celebración del 49 CONGRESO INTERNACIONAL DE AMERICANISTAS (49 ICA), durante el cual se congregaron más de un millar de estudiosos americanistas, procedentes de todo el mundo. Pues bien, nuestro Simposio fue uno más de los que se convocaron dentro del marco del citado Congreso. La Arqueología Industrial, y en concreto la relacionada con el Patrimonio Minero-Metalúrgico, es una preocupación constante de los coordinadores del Simposio, y también la de los participantes en el mismo. La recuperación de esta parte del patrimonio es ineludible para todos nosotros, y creemos firmemente que es una labor a la que tienen que dedicarse los esfuerzos suficientes, por parte de los estamentos sociales, con el fin de evitar su perdida. Entonces podría ser irreparable que perdiéramos uno de nuestros orígenes, y ya sabemos que como dijo un autor (Salvador Espriu), en relación a otro contexto, ".. quien pierde sus orígenes, pierde su identidad". Muchos de los participantes en este Simposio, entre los procedentes de nuestro país, ya venimos desarrollando esta labor, tanto de una forma particular, como colectiva en el seno de la Sociedad Española para la defensa del Patrimonio Geológico y Minero (SEDPGYM)

La enseñanza de la Mineralogía y de la Petrología, con especial atención a las Escuelas de Minas

Suponemos que los primeros estudios mineralógicos se realizan dentro de las Academias filosóficas, las Cátedras personales o gracias a la transmisión oral maestro-discípulo, sin que la Mineralogía sea una materia específica en ningún plan de estudios conocido. Las primeras noticias de que disponemos, sobre la institucionalización de estas enseñanzas, proceden de Freiberg, en Alemania, y podemos encuadrarlas dentro del marco del aprendizaje del arte minero