Static locality analysis for cache management

Most memory references in numerical codes correspond to array references whose indices are affine functions of surrounding loop indices. These array references follow a regular predictable memory pattern that can be analysed at compile time. This analysis can provide valuable information like the locality exhibited by the program, which can be used to implement more intelligent caching strategy. In this paper we propose a static locality analysis oriented to the management of data caches. We show that previous proposals on locality analysis are not appropriate when the proposals have a high conflict miss ratio. This paper examines those proposals by introducing a compile-time interference analysis that significantly improve the performance of them. We first show how this analysis can be used to characterize the dynamic locality properties of numerical codes. This evaluation show for instance that a large percentage of references exhibit any type of locality. This motivates the use of a dual data cache, which has a module specialized to exploit temporal locality, and a selective cache respectively. Then, the performance provided by these two cache organizations is evaluated. In both organizations, the static locality analysis is responsible for tagging each memory instruction accordingly to the particular type(s) of locality that it exhibits.Peer ReviewedPostprint (published version

Electrochemical Detection of Fluoroquinolone Antibiotics in Milk Using a Magneto Immunosensor

An amperometric magneto-immunosensor (AMIS) for the detection of residues of fluoroquinolone antibiotics in milk samples is described for the first time. The immunosensor presented combines magnetic beads biomodified with an antibody with a broad recognition profile of fluoroquinolones, a haptenized enzyme and a magnetic graphite-epoxy composite (m-GEC) electrode. After the immunochemical reaction with specific enzyme tracer, the antibody biomodified magnetic beads are easily captured by an electrode made of graphite-epoxy composite containing a magnet, which also acts as transducer for the electrochemical detection. In spite of the complexity of milk, the use of magnetic beads allows elimination of potential interferences caused by the matrix components; hence the AMIS could perform quantitative measurements, directly in these samples, without any additional sample cleanup or extraction step. The immunosensor is able to detect up to seven different fluoroquinolones far below the MRLs defined by the UE for milk; for example ciprofloxacin is detected directly in milk with an IC50 of 0.74 μg/L and a LOD of 0.009 μg/L. This strategy offers great promise for rapid, simple, cost-effective, and on-site analysis fluoroquinolones in complex samples

A day-ahead irradiance forecasting strategy for the integration of photovoltaic systems in virtual power plants

Encouraged by the considerable cost reduction, small-scale solar power deployment has become a reality during the last decade. However, grid integration of small-scale photovoltaic (PV) solar systems still remains unresolved. High penetration of Renewable Energy Sources (RESs) results in technical challenges for grid operators. To address this, Virtual Power Plants (VPPs) have been defined and developed to manage distributed energy resources with the aim of facilitating the integration of RESs. This paper introduces a hybrid irradiance forecasting approach aimed at facilitating the integration of PV systems into a VPP, especially when a historical irradiance dataset is exiguous or non-existent. This approach is based on Artificial Neural Networks (ANNs) and a novel similar hour-based selection algorithm, has been tested for a real PV installation, and has been validated also considering irradiance measurements from an aggregation of ground-based meteorological stations, which emulate the nodes of a VPP. Under a reduced historical dataset, the results show that the proposed similar hour-based method produces the best forecasts with regard to those obtained by the ANN-based approach. This is particularly true for one-month and two-month datasets minimizing the mean error by 16.32% and 9.07% respectively. Finally, to demonstrate the potential of the proposed approach, a comparative analysis has been carried out between the hybrid method and the most used benchmarks in the literature, namely, the persistence method and the method based on similar days. It has been demonstrated conclusively that the proposed model yields promising results regardless the length of the historical dataset.Comunidad de MadridAgencia Estatal de Investigació

Electrochemical detection of fluoroquinolone antibiotics in milk using a magneto immunosensor

An amperometric magneto-immunosensor (AMIS) for the detection of residues of fluoroquinolone antibiotics in milk samples is described for the first time. The immunosensor presented combines magnetic beads biomodified with an antibody with a broad recognition profile of fluoroquinolones, a haptenized enzyme and a magnetic graphite-epoxy composite (m-GEC) electrode. After the immunochemical reaction with specific enzyme tracer, the antibody biomodified magnetic beads are easily captured by an electrode made of graphite-epoxy composite containing a magnet, which also acts as transducer for the electrochemical detection. In spite of the complexity of milk, the use of magnetic beads allows elimination of potential interferences caused by the matrix components; hence the AMIS could perform quantitative measurements, directly in these samples, without any additional sample cleanup or extraction step. The immunosensor is able to detect up to seven different fluoroquinolones far below the MRLs defined by the UE for milk; for example ciprofloxacin is detected directly in milk with an IC50 of 0.74 μg/L and a LOD of 0.009 μg/L. This strategy offers great promise for rapid, simple, cost-effective, and on-site analysis fluoroquinolones in complex samples. © 2014 by the authors; licensee MDPI, Basel, Switzerland.This work has been supported by the Ministry of Science and Innovation (Spain) (Contract number AGL2008-05578-C05-01 and by the European Community (FP7-FOOD-2007-211326 and FP7-OCEAN-2013-1-614168). The Nb4D group is a consolidated Grup de Recerca de la Generalitat de Catalunya and has support from the Departament d’Universitats, Recerca i Societat de la Informació la Generalitat de Catalunya (expedient 2014 SGR 1484). CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008–2011, IniciativaIngenio 2010, Consolider Program, CIBER Actions and is financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Foundation. DG had a fellowship from the Fundación EROSKI.Peer Reviewe

Numerical mode matching for sound propagation in silencers with granular material

[EN] This work presents an efficient numerical approach based on the combination of the mode matching technique and the finite element method (FEM) to model the sound propagation in silencers containing granular material and to evaluate their acoustic performance through the computation of transmission loss (TL). The methodology takes into account the presence of three-dimensional (3D) waves and the corresponding higher order modes, while reducing the computational expenditure of a full 3D FEM calculation. First, the wavenumbers and transversal pressure modes associated with the silencer cross section are obtained by means of a two-dimensional FEM eigenvalue problem, which allows the consideration of arbitrary transversal geometries and material heterogeneities. The numerical approach considers the possibility of using different filling levels of granular material, giving rise to cross sections with abrupt changes of properties located not only in the usual central perforated passage, but also in the transition between air and material, that involves a significant change in porosity. After solving the eigenvalue problem, the acoustic fields (acoustic pressure and axial velocity) are coupled at geometric discontinuities between ducts through the compatibility conditions to obtain the complete solution of the wave equation and the acoustic performance (TL). The granular material is analysed as a potential alternative to the traditional dissipative silencers incorporating fibrous absorbent materials. Sound propagation in granular materials can be modelled through acoustic equivalent properties, such as complex and frequency dependent density and speed of sound. TL results computed by means of the numerical approach proposed here show good agreement with full 3D FEM calculations and experimental measurements. As expected, the numerical mode matching outperforms the computational expenditure of the full 3D FEM approach. Different configurations have been studied to determine the influence on the TL of several parameters such as the size of the material grains, the filling level of the chamber, the granular material porosity and the geometry of the silencer cross section.Project supported by a 2016 BBVA Foundation, Spain Grant for Researchers and Cultural Creators. The BBVA Foundation takes no responsibility for the opinions, remarks or content included in the project and/or the results thereof, which are the sole responsibility of the authors. Support of Generalitat Valenciana (Conselleria d'Educacio, Investigacid, Cultura i Esport), Spain through project Prometeo/2016/007 is also acknowledged.Sánchez Orgaz, EM.; Denia Guzmán, FD.; Baeza González, LM.; Kirby, R. (2019). Numerical mode matching for sound propagation in silencers with granular material. Journal of Computational and Applied Mathematics. 350:233-246. https://doi.org/10.1016/j.cam.2018.10.030S233246350Denia, F. D., Sánchez-Orgaz, E. M., Martínez-Casas, J., & Kirby, R. (2015). Finite element based acoustic analysis of dissipative silencers with high temperature and thermal-induced heterogeneity. Finite Elements in Analysis and Design, 101, 46-57. doi:10.1016/j.finel.2015.04.004Astley, R. J. (1996). FE mode-matching schemes for the exterior Helmholtz problem and their relationship to the FE-DtN approach. Communications in Numerical Methods in Engineering, 12(4), 257-267. doi:10.1002/(sici)1099-0887(199604)12:43.0.co;2-8Glav, R. (1996). THE POINT-MATCHING METHOD ON DISSIPATIVE SILENCERS OF ARBITRARY CROSS-SECTION. Journal of Sound and Vibration, 189(1), 123-135. doi:10.1006/jsvi.1996.0009GLAV, R. (2000). THE TRANSFER MATRIX FOR A DISSIPATIVE SILENCER OF ARBITRARY CROSS-SECTION. Journal of Sound and Vibration, 236(4), 575-594. doi:10.1006/jsvi.2000.2994Kirby, R. (2003). Transmission loss predictions for dissipative silencers of arbitrary cross section in the presence of mean flow. The Journal of the Acoustical Society of America, 114(1), 200-209. doi:10.1121/1.1582448Kirby, R. (2009). A comparison between analytic and numerical methods for modelling automotive dissipative silencers with mean flow. Journal of Sound and Vibration, 325(3), 565-582. doi:10.1016/j.jsv.2009.03.032Fang, Z., & Ji, Z. L. (2014). Numerical Mode Matching Approach for Acoustic Attenuation Predictions of Double-Chamber Perforated Tube Dissipative Silencers with Mean Flow. Journal of Computational Acoustics, 22(02), 1450004. doi:10.1142/s0218396x14500040Yang, L., Ji, Z. L., & Wu, T. W. (2015). Transmission loss prediction of silencers by using combined boundary element method and point collocation approach. Engineering Analysis with Boundary Elements, 61, 265-273. doi:10.1016/j.enganabound.2015.08.004Denia, F. D., Sánchez-Orgaz, E. M., Baeza, L., & Kirby, R. (2016). Point collocation scheme in silencers with temperature gradient and mean flow. Journal of Computational and Applied Mathematics, 291, 127-141. doi:10.1016/j.cam.2015.02.007Kirby, R. (2008). Modeling sound propagation in acoustic waveguides using a hybrid numerical method. The Journal of the Acoustical Society of America, 124(4), 1930-1940. doi:10.1121/1.2967837Denia, F. D., Martínez-Casas, J., Carballeira, J., Nadal, E., & Fuenmayor, F. J. (2018). Computational performance of analytical methods for the acoustic modelling of automotive exhaust devices incorporating monoliths. Journal of Computational and Applied Mathematics, 330, 995-1006. doi:10.1016/j.cam.2017.03.010Allard, J. F., & Atalla, N. (2009). Propagation of Sound in Porous Media. doi:10.1002/9780470747339Li, J., Zhao, S., & Ishihara, K. (2013). Study on acoustical properties of sintered bronze porous material for transient exhaust noise of pneumatic system. Journal of Sound and Vibration, 332(11), 2721-2734. doi:10.1016/j.jsv.2012.12.031Cobo, P., & Simón, F. (2016). A comparison of impedance models for the inverse estimation of the non-acoustical parameters of granular absorbers. Applied Acoustics, 104, 119-126. doi:10.1016/j.apacoust.2015.11.006Kirby, R., & Lawrie, J. B. (2005). A point collocation approach to modelling large dissipative silencers. Journal of Sound and Vibration, 286(1-2), 313-339. doi:10.1016/j.jsv.2004.10.016Murphy, J. E., & Chin‐Bing, S. A. (1989). A finite‐element model for ocean acoustic propagation and scattering. The Journal of the Acoustical Society of America, 86(4), 1478-1483. doi:10.1121/1.398708Pierce, A. D. (1990). Wave equation for sound in fluids with unsteady inhomogeneous flow. The Journal of the Acoustical Society of America, 87(6), 2292-2299. doi:10.1121/1.399073Selamet, A., & Ji, Z. L. (1998). ACOUSTIC ATTENUATION PERFORMANCE OF CIRCULAR EXPANSION CHAMBERS WITH OFFSET INLET/OUTLET: I. ANALYTICAL APPROACH. Journal of Sound and Vibration, 213(4), 601-617. doi:10.1006/jsvi.1998.1514Selamet, A., Xu, M. B., Lee, I.-J., & Huff, N. T. (2005). Analytical approach for sound attenuation in perforated dissipative silencers with inlet/outlet extensions. The Journal of the Acoustical Society of America, 117(4), 2078-2089. doi:10.1121/1.1867884Denia, F. D., Selamet, A., Fuenmayor, F. J., & Kirby, R. (2007). Acoustic attenuation performance of perforated dissipative mufflers with empty inlet/outlet extensions. Journal of Sound and Vibration, 302(4-5), 1000-1017. doi:10.1016/j.jsv.2007.01.005Payri, F., Broatch, A., Salavert, J. M., & Moreno, D. (2010). Acoustic response of fibrous absorbent materials to impulsive transient excitations. Journal of Sound and Vibration, 329(7), 880-892. doi:10.1016/j.jsv.2009.10.015P. Glover, Petrophysics MSc Course Notes, MSc Lecture Notes, University of Leeds

Una propuesta didáctica en 3º E.S.O para trabajar el pensamiento matemático avanzado haciendo uso de Scratch

En este trabajo se presenta una propuesta didáctica llevada a cabo con alumnos de 3º de E.S.O, basada en la programación del algoritmo de Euclides para el máximo común divisor, con la herramienta tecnológica Scratch. Esta propuesta permitió trabajar, elementos propios del pensamiento matemático avanzado (PMA) como son la abstracción, la formalización y la generalización a través de una metodología basada en la Teoría de las Situaciones Didácticas (TSD). Se observó cómo el diseño de las fichas de trabajo, siguiendo la TSD, junto con la organización de la clase en grupos, favoreció debate y la obtención de resultados

Coordinación vertical de la formación en Cálculo de Estructuras dentro del Grado en Ingeniería Civil: Desarrollo de aplicaciones interactivas para la docencia

Las nuevas tecnologías aplicadas a la enseñanza permiten la visualización de fenómenos físicos y su relación con la base matemática utilizada en la modelización de los mismos. En este trabajo se ha utilizado el programa Mathematica para realizar aplicaciones ilustrativas de distintos conceptos básicos para el cálculo de estructuras de ingeniería civil y edificación. Se han tratado temas como la reología, la plastificación de los materiales, la relación entre tensiones y deformaciones de los sólidos elásticos o la dinámica estructural, siempre desde un punto de vista teórico-práctico y tratando de mantener en todo momento un carácter interactivo que permita la participación activa de los estudiantes. Cada aplicación compagina los fundamentos teóricos y la influencia de los parámetros implicados, con la visualización en forma de gráfico animado de la función resultante

Accurate,robust and harmonized implementation of morpho-functional imaging in treatment planning for personalized radiotherapy

In this work we present a methodology able to use harmonized PET/CT imaging in dose painting by number (DPBN) approach by means of a robust and accurate treatment planning system. Image processing and treatment planning were performed by using a Matlab-based platform, called CARMEN, in which a full Monte Carlo simulation is included. Linear programming formulation was developed for a voxel-by-voxel robust optimization and a specific direct aperture optimization was designed for an efficient adaptive radiotherapy implementation. DPBN approach with our methodology was tested to reduce the uncertainties associated with both, the absolute value and the relative value of the information in the functional image. For the same H&N case, a single robust treatment was planned for dose prescription maps corresponding to standardized uptake value distributions from two different image reconstruction protocols: One to fulfill EARL accreditation for harmonization of [18F]FDG PET/CT image, and the other one to use the highest available spatial resolution. Also, a robust treatment was planned to fulfill dose prescription maps corresponding to both approaches, the dose painting by contour based on volumes and our voxel-by-voxel DPBN. Adaptive planning was also carried out to check the suitability of our proposal. Different plans showed robustness to cover a range of scenarios for implementation of harmonizing strategies by using the highest available resolution. Also, robustness associated to discretization level of dose prescription according to the use of contours or numbers was achieved. All plans showed excellent quality index histogram and quality factors below 2%. Efficient solution for adaptive radiotherapy based directly on changes in functional image was obtained. We proved that by using voxel-by-voxel DPBN approach it is possible to overcome typical drawbacks linked to PET/CT images, providing to the clinical specialist confidence enough for routinely implementation of functional imaging for personalized radiotherapy.Junta de Andalucía (FISEVI, reference project CTS 2482)European Regional Development Fund (FEDER

Límite infinito de sucesiones y divergencia

En este documento se muestran las dificultades para seleccionar una definición de límite infinito de sucesiones entre profesores. Estas dificultades están propiciadas por el efecto que el término divergencia ocasiona en dichas definiciones. Las dificultades, mostradas a través de una consulta a expertos, están presentes tanto en profesores como en autores de libros de texto y en este documento se muestran ejemplos de las mismas. Se aporta además una nueva acepción de sucesión divergente y se prepara el camino para un estudio posterior de la definición seleccionada

Una propuesta que facilita el uso eficaz de los libros de texto a los futuros profesores de matemáticas

En este trabajo se presentan los primeros resultados de una experiencia piloto desarrollada en el marco del Máster de Formación de Profesores de Matemáticas de Secundaria, Bachillerato e Idiomas (MFP) de la Universidad Rey Juan Carlos de Madrid (URJC), en la que se trata de obtener información, a través de cuestionarios diseñados a tal efecto por el equipo de investigadores que presenta esta propuesta, sobre qué conocimientos matemáticos específicos necesita un profesor de matemáticas para usar de manera eficaz en el aula el libro de texto. Como punto de partida, y a través del trabajo colaborativo de los autores de la propuesta aquí presentada, se ha diseñado un conjunto de ítems para analizar minuciosamente los contenidos de una Unidad Didáctica de un libro de texto