High-performance computing: the essential tool and the essential challenge

[EN] Prolog to the Journal of Supercomputing, volume 73, issue 1.We would also like to acknowledge to the “Ministerio de Educación y Ciencia” of Spain, for its support to the Spanish CAPAP-H5 network (HPC in Heterogeneous Systems, TIN2014-53522-REDT), and to the “Ministerio de Economía y Competitividad” from Spain/FEDER for supporting Grants TEC2015-67387-C4-1-R and TEC2015-67387-C4-3-R.Alonso-Jordá, P.; Ranilla, J.; Vigo-Aguiar, J. (2017). High-performance computing: the essential tool and the essential challenge. The Journal of Supercomputing. 73(1):1-3. https://doi.org/10.1007/s11227-016-1922-5S1373

Computing the sets of totally symmetric and totally conjugate orthogonal partial Latin squares by means of a SAT solver

Conjugacy and orthogonality of Latin squares have been widely studied in the literature not only for their theoretical interest in combinatorics, but also for their applications in distinct fields as experimental design, cryptography or code theory, amongst others. This paper deals with a series of binary constraints that characterize the sets of partial Latin squares of a given order for which their six conjugates either coincide or are all of them distinct and pairwise orthogonal. These constraints enable us to make use of a SAT solver to enumerate both sets. As an illustrative application, it is also exposed a method to construct totally symmetric partial Latin squares that gives rise, under certain conditions, to new families of Lie partial quasigroup rings

Homogenization of the Poisson equation with Dirichlet conditions in random perforated domains

Ministerio de Ciencia e InnovaciónJunta de Andalucí

Time Series on Functional Service Life of Buildings using Fuzzy Delphi Method

The functional service life of heritage buildings, defined as the time period during which the building fulfils the requirements for which it was designed, is a complex system that has still not been fully resolved and continues to be the object of research regarding its social, economic and cultural importance. This paper presents an application for analysing time series that reflect the state of building performance over time. To this end, historical time records are used that provided data that could be interpreted by experts in the field. The latter can then evaluate the input variables (vulnerability and risk) using the expert system for predicting the service life of buildings, Fuzzy Building Service Life (FBSL), this methodology put together the fuzzy logic tools and Delphi method. This model provides output data on the state of functionality or performance of each buildings at each moment in time whenever information records are available. The Delphi Method is used to eliminate expert subjectivity, establishing an FDM-type assessment methodology that effectively quantifies the service life of buildings over time. The application is able to provide significant data when generating future preventive maintenance programmes in architectural-cultural heritage buildings. It can also be used to optimise the resources invested in the conservation of heritage buildings. In order to validate this system, the FDM methodology is applied to some specific building examples.Ministerio de Economía y Competitividad de España, Project ART-RISK - BIA2015-64878-RMinisterio de Economía y Competitividad de España MTM 2015-65397-

A faithful functor among algebras and graphs

The problem of identifying a functor between the categories of algebras and graphs is currently open. Based on a known algorithm that identifies isomorphisms of Latin squares with isomorphism of vertex-colored graphs, we describe here a pair of graphs that enable us to find a faithful functor between finite-dimensional algebras over finite fields and these graphs

Formación y tutorización activa mediante Web 3D

Memoria ID-0019. Ayudas de la Universidad de Salamanca para la Innovación Docente, curso 2008-2009.El proyecto Formación y tutorización activa mediante Web 3D, ha permitido poner en marcha el portal fcienciasvirtual.usal.es en el que se presenta un mundo virtual de la Facultad de Ciencias. La Web 3D de la facultad de ciencias facilita la interacción entre estudiantes y profesores y es una herramienta de soporte a la docencia. Se trata de un entorno inmersivo 3D, adaptado a la Facultad y de tipo experimental

Análisis numérico II

Memoria ID-0175. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2009-2010.La memoria de innovación de 2010 resulto en la presenta monografia. Esta monografía se ciñe a la materia estudiada en la asignatura de Análisis Numérico II del grado de Matemáticas. Debido a la ausencia de material en Español (lo cuál ha llegado a ser motivo de queja para los alumnos) que sirva a los estudiantes de guía para el estudio, hemos considerado adecuado poner por escrito algunas ideas que les puedan servir en el futuro de la asignatura. Los presentes apuntes se dedican al estudio de los métodos más clásicos de resolución de ecuaciones diferenciales. Hemos dividido el trabajo en tres: i) Un primer capítulo que les sirva de introducción a los métodos, con diferentes definiciones y ejemplos, que sirven al alumno de antesala ante lo que se avecina. ii) El segundo capítulo está dedicado a los Métodos Runge-Kutta, especialmente a los explícitos. iii) Por _ultimo, el capítulo tres se dedica al estudio de los métodos multipaso: Adams-Bashforth, Adams-Moulton, BDF, Stormer y Cowell. Puesto que la asignatura tiene tanto parte teórica como práctica, en cada capítulo hay una serie de problemas que, esperemos, sirvan al alumno a comprender mejor los términos más complejos de la asignatura.

www.elsevier.com/locate/cam A fourth-order Runge–Kutta method based on BDF-type Chebyshev approximations

In this paper we consider a new fourth-order method of BDF-type for solving stiff initial-value problems, based on the interval approximation of the true solution by truncated Chebyshev series. It is shown that the method may be formulated in an equivalent way as a Runge–Kutta method having stage order four. The method thus obtained have good properties relatives to stability including an unbounded stability domain and large �-value concerning A(�)-stability. A strategy for changing the step size, based on a pair of methods in a similar way to the embedding pair in the Runge–Kutta schemes, is presented. The numerical examples reveals that this method is very promising when it is used for solving stiff initial-value problems