La formación del concepto de función en alumnos de educación media superior

En este artículo se describe la realización de un taller cuyo diseño responde al marco de una investigación en proceso, que explora los saberes que sobre el concepto de función tienen los alumnos de educación media superior (EMS) y pretende analizar los efectos que presenta la puesta en escena de situaciones didácticas sobre la formación del concepto de función. En la primera etapa de la investigación se están explorando dichos saberes en 30 alumnos de EMS y 10 de los primeros semestres de la licenciatura en matemáticas en Acapulco, Guerrero, México. También se han diseñado situaciones didácticas para abordar este concepto, a fin de que se instrumenten en la escuela. Con estos avances se estructuró el taller para interesados en este campo y realizado en Relme 17 con la participación de siete profesores

Optimized Design of Combline Filters with Transmission Zeros

[EN] The objective of this paper is to demonstrate how inline combline filters can be designed to implement transmission zeros in the filter transfer function. Following the design procedure described in this paper, up to N-1 transmission zeros can be implemented with a filter of order N. In addition to theory, comparisons between simulated and measured results are also presented. The agreement between simulation and measurements is indeed good, thereby fully validating the new combline filter topology, and the proposed design technique.Vague Cardona, JJ.; Ossorio García, J.; Cogollos, S.; Boria Esbert, VE.; Guglielmi, M. (2019). Optimized Design of Combline Filters with Transmission Zeros. IEEE. 1-3. https://doi.org/10.1109/NEMO.2019.8853819S1

Waveguide Quadruplet Diplexer for Multi-Beam Satellite Applications

[EN] The objective of this paper is to describe the design of an innovative and low-cost diplexer for Ka-band multi-beam satellite applications. The device is based on the use of two quadruplets to implement a number of transmission zeros (TZs) thus obtaining high-selectivity quasi-elliptic transfer functions. The resulting diplexer structure is particularly flexible in terms of layout, does not require tuning and has an excellent high-power behavior. In addition to theory, we compare the results of our simulations with the measurements obtained with a manufactured breadboard. The comparison shows excellent agreement thereby fully validating both the design procedure, and the new diplexer structure.This work was supported in part by the MINECO (Spanish Government) through Research and Development Project under Grant TEC2016-75934-C4-1-R, and in part by the Research and Development Technicians under Grant PTA2015-10839-I.Ossorio García, J.; Melgarejo Lermas, JC.; Cogollos, S.; Boria Esbert, VE.; Guglielmi, M. (2020). Waveguide Quadruplet Diplexer for Multi-Beam Satellite Applications. IEEE Access. 8:110116-110128. https://doi.org/10.1109/ACCESS.2020.3002818S110116110128

Bottom-up control of sardine and anchovy population cycles in the canary current: insights from an end-to-end model simulation

Sardine and anchovy can exhibit dramatic decadal-scale shifts in abundance in response to climate variability. Sharpe declines of these populations entail particularly serious commercial and ecological consequences in eastern boundary current ecosystems, where they sustain major world fisheries and provide the forage for a broad variety of predators. Understanding the mechanisms and environmental forcing that drive the observed fish variability remains a challenging problem. The modelling study presented here provides an approach that bridges a comprehensive database with an end-to-end modelling framework enabling the investigation of the sources of variability of sardine and anchovy in the Canary Current System. Different biological traits and behaviour prescribed for sardine and anchovy gave rise to different distribution and displacements of the populations, but to a rather synchronous variability in terms of abundance and biomass, in qualitative agreement with historical landing records. Analysis of years with anomalously high increase and decline of the adult population points to food availability (instead of temperature or other environmental drivers) as the main environmental factor determining recruitment for both sardine (via spawning and survival of feeding age-0 individuals) and anchovy (via survival of feeding age-0). Consistent with this, the two species thrive under enhanced upwelling-favourable winds, but only up to some threshold of the wind velocity beyond which larval drift mortality exceeds the positive effect of the extra food supply. Based on the analysis of the simulation, we found that anchovy larvae are particularly vulnerable to enhanced wind-driven advection, and as such do better with more moderate upwelling than sardines.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Population distribution and biomass variability of sardine and anchovy in the Canary current system as simulated by an end-to-end coupled model

Small pelagic fishes as sardine and anchovy account for as much as 20-25% of the world fisheries catch. They are particularly abundant in the four major eastern boundary upwelling ecosystems, where high levels of biological productivity are sustained by the supply of nutrient-rich water from beneath the photic zone. An intrinsic and puzzling feature of small pelagic fish is the large fluctuations of their population, typically occurring at decadal scales. The causes for such fluctuations have been extensively analyzed and discussed in the literature, yet our understanding of the mechanism involved is very limited. End-to-end models are emerging tools useful to test hypothesis for such fish population variability or to gain new insights into the problem. This comprehensive and complex model approach is now becoming possible largely thanks to the present-day computer power. This contribution focuses on the population dynamics of sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Canary Current Upwelling Ecosystem. We describe and present the results of an end-to-end coupled model simulation including these two small pelagic species. The end-to-end application includes three model components: the ROMS circulation sub-model, the lower trophic ecosystem sub-model NEMURO, and a recently developed individual-based model for the fish (Rose et al. 2015; Fiechter et al. 2015). The computational grid for the three models covers NW Africa and the Western Iberian Peninsula at a spatial resolution of 12 km. This resolution is sufficient for certain eddy variability to occur in ROMS. Different biological traits were prescribed for anchovy and sardine: temperature optimum, diet preferences, and the onset and duration of the spawning season, among others. A hind-cast simulation of the period 1958-2007 was carried out. Model results reveal a fairly different behavior of sardine and anchovy. Anchovies gather off the northern part of Morocco and the Gulf of Cadiz, whereas sardines appear more scattered across the domain, further offshore, and further south, where upwelling favorable conditions take place year round. Both species exhibit decadal-scale fluctuations in both the location of the center of mass of the population and their biomass abundance; the latter being reasonably correlated with historical landing records.Universidad de Málaga. Campus de Excelencia Internacional del Mar CEIMAR. Campus de Excelencia Andalucía Tec

On Space Mapping Techniques for Microwave Filter Tuning

[EN] Space mapping (SM) and aggressive SM (ASM) techniques are widely used in the synthesis and design of microwave filters. Their popularity stems from the inherent simplicity of the procedures and from their effectiveness. The objective of this article is to extend the state of the art of these techniques by discussing how they can also be used very effectively to tune microwave filters. In addition to the theory, the successful tuning of a six-pole inductive waveguide filter is discussed in detail, thereby fully validating the proposed SM techniques.This work was supported by funds from the "La Caixa" Foundation (Code: B004442) and Agencia Estatal de Investigacion (AEI) and Union Europea through Fondo Europeo de Desarrollo Regional-FEDER-"Una manera de hacer Europa" (AEI/FEDER, UE), under Research Project TEC2016-75934-C4-1-RMelgarejo-Lermas, JC.; Ossorio-García, J.; Cogollos, S.; Guglielmi, M.; Boria Esbert, VE.; Bandler, JW. (2019). On Space Mapping Techniques for Microwave Filter Tuning. IEEE Transactions on Microwave Theory and Techniques. 67(12):4860-4870. https://doi.org/10.1109/TMTT.2019.2944361S48604870671

A Multi-Criteria Meta-Fuzzy-Scheduler for Independent Tasks in Grid Computing

The paradigm of distributed computation in heterogeneous resources, grid computing, has given rise to a large amount of research on resource scheduling. This paper presents a Meta-Scheduler for grid computing that does not need any given information about tasks length or tasks arrival time unlike traditional dynamic heuristics. Our Meta-Scheduler is of multi-criteria type, because it solves two conflicting objectives: minimize the makespan of a set of tasks and distribute these tasks in a balanced way among the resources of the Grid. Experimental results using fuzzy scheduler show that, through our proposal, we achieve these two objectives and improve dynamic heuristics presented in prior literature

Kinematics of recreational runners with iliotibial band injury

According to the literature, the risk of developing iliotibial band syndrome (ITBS) is related to the running technique of each runner. The purpose of this study was to investigate whether differences exist in the running technique of runners with ITBS and healthy runners. The sample was composed of 60 recreational runners (30 healthy runners and 30 with ITBS). A 3D kinematic analysis was performed to measure 3D joint angles of the lower limb. Reaction forces in the stance phase of running were also determined. Runners in the ITBS group exhibited significantly lower contact time, knee valgus, peak knee flexion and hip rotation. Of note, gender-based differences were observed. No differences were found between groups in hip adduction angle, tibial internal rotation and foot kinematics. The runners with current ITBS showed an altered kinematic profile. Male and female runners with ITBS showed different alterations in running kinematics. These results suggest that gender should be considered when investigating the biomechanical etiology of ITBS

Diseño, Implantación y Desarrollo de un Máster en Ingeniería Informática

Este artículo describe el Máster en Ingeniería Informática de la Universidad de Oviedo, impartido en la Escuela Politécnica Superior de Ingeniería de Gijón (EPI). Es uno de los primeros estudios de máster en Ingeniería Informática implantados en España conforme a las Directrices del Consejo de Universidades para estudios conducentes a la profesión de Ingeniero en Informática (Resolución de 8 de junio de 2009, BOE 187, martes 4 de agosto de 2009).This paper provides an overview of the Informatics and Computing Engineering Master Degree at the Gijon Polytechnic School of Engineering (University of Oviedo). This is one of the earliest Informatics and Computing Engineering master’s in Spain designed according the National recommendations for the Informatics Engineering professio

Stress-induced waveguides in Nd:YAG by simultaneous double-beam irradiation with femtosecond pulses

We report on the fabrication of stress-induced waveguides in Nd:YAG (neodymium doped yttrium aluminum garnet, Nd:Y3Al5O12) by simultaneous double-beam irradiation with femtosecond laser pulses. An interferometer was used to generate two femtosecond laser beams that, focused with certain lateral separation inside the crystal, produced two parallel damage tracks with a single scan. The propagation of the mechanical waves simultaneously created in both focal spots produced a highly symmetrical stress field that is clearly revealed in micro-luminescence maps. The optical properties of the double-beam waveguides are studied and compared to those of single-beam irradiation, showing relevant differences. The creation of more symmetric stress patterns and a slight reduction of propagation losses are explained in terms of the fact that simultaneous inscription allows for a drastic reduction in the magnitude of “incubation” effects related to the existence of pre-damaged states.This work was supported by the Ministerio de Economía y Competitividad under Projects FIS2013-44174-P and MAT2013-47395- C4-1-R. The femtosecond laser inscription was carried out in the Spanish Pulsed Laser Center (CLPU) with their Laser Service (High-Repetition-Rate laser system) and their technical assistance, in the framework of the access agreement concerning USAL staff