Alguns elements per a la motivació. Aspectes que desperten l’interès per les matemàtiques a l'aula

La motivació dels estudiants a les aules és un tema que preocupa a tots els professors de l’ensenyament. L’ideal seria que es pogués respondre a la pregunta “com es pot fer perquè els alumnes estiguin interessats a les aules?” Aquesta resposta encara no s’ha trobat, i tot apunta a que no sigui una resposta fàcil. En aquest treball es defineix un concepte clau dins el que és la motivació: la motivació intrínseca. Aquest tipus de motivació és la que fa que la gent faci activitats “perquè vol” i no perquè hi ha algun element extern que la força a fer-ho. A la definició es tracta de descriure, segons diferents autors, els components en que es pot dividir aquesta motivació. Al treball també es destaquen dos aspectes que controlen la motivació dels alumnes: el valor que donen als seus objectius i les atribucions causals que realitzen d’allò que perceben. Es proposen algunes actuacions a l’aula encarades a aprofitar aquests aspectes. S’ha fet també un breu estudi sobre dos tipus d’activitats de tipus no estàndard per a realitzar a l’aula. Per una banda, els problemes contextualitzats en les quals es basa la teoria de l’Educació Matemàtica Realista de l’escola Freudenthal, dels quals a la secció final del treball es porta una activitat concreta a l’aula, i d’altra banda, l’aprenentatge per projectes. A més, s’analitzen dues classes de matemàtiques a aules reals, identificant els elements de motivació utilitzats per professors diferents. Per últim, es descriu una activitat concreta que s’ha portat a l’aula: “L’aritmètica del rellotge”. És, com s’ha dit, del tipus “problema contextualitzat”. S’ha fet un petit anàlisi de l’actuació i de la valoració de l’activitat per part dels alumnes mitjançant una enquesta que han respost a l’aula

Intersection between class and gender and its effect on the quality of employment in Chile

Indexación: Web of Science; Scopus.En este artículo se analiza el efecto de la intersección entre clase y género sobre la calidad del empleo en Chile. La medida de posición de clase utilizada está basada en la propuesta de Erik O. Wright y la calidad del empleo en una medida multidimensional, que incluye un índice de condiciones objetivas de empleo y dos índices de condiciones subjetivas (motivación en el trabajo y percepción del control sobre el proceso de trabajo). Los resultados demuestran que la clase y el género determinan diferencias significativas en la calidad objetiva y subjetiva del empleo. Sin embargo, los datos también indican que el género (particularmente, el hecho de ser mujer) no actúa necesariamente como “amplificador” de las desigualdades de clase observadas en el mercado laboral. A partir de esto, al final del artículo se plantean algunas reflexiones sobre cómo opera la intersección entre clase y género en el mercado laboral chileno.This study explores the impact of the intersection between class and gender on the quality of employment in Chile. The method used to measure social class position is based on the work of Erik O. Wright, while, for the quality of employment, a multidimensional measurement was used, including one index for objective working conditions and two indices for subjective ones (motivation on the job and the perception of control over work processes). The results demonstrate that class and gender give rise to signifcant differences in objective and subjective job quality. However, the data also indicate that gender (more specifcally, the fact of being female) does not necessarily amplify the class-based inequalities observed in the labour market. Drawing on these fndings, a number of thoughts about how the class/gender intersection operates in the Chilean labour market are shared in the fnal section of this studyhttp://hdl.handle.net/11362/4079

A model development for reconstruction of three-dimensional defects based on MFL signals

Corrosion has been statistically placed as the primary cause for pipeline failures well beyond other factors. The inability to accurately size corrosion defects located in pipelines can result in erroneous integrity strategies with fatal consequences, even when appropriate inspection processes have been conducted. Underestimation or overestimation of the defect size causes on one hand pipeline failures and on the other unnecessary assessments. Several strategies for defect sizing based on MFL signals have been developed in recent years. However, the industry still urges for reliability improvements. The current thesis develops a model based on calibration curves for the reconstruction of defects, based on MFL signals. A thorough study of different parameters involved allows for the understanding of the relationships between defect dimensions and MFL signal features. The methodology of this research includes theoretical, numerical and experimental assessments resulting in the development of a reliable three-dimensional model. Calibration curves are reported for inner as well as for outer defect configuration. Such curves permit the accurate establishment of the defect length and depth by means of the signal duration and amplitude. The results of this study for a single defect can be further implemented in order to investigate the superposition of MFL signals coming from adjacent defects. The MFL signal superposition is demonstrated through simulations and experiments.Nach der Statistik ist Korrosion, neben anderen Faktoren, die primäre Ursache für Rohrleitungsversagen. Die Unfähigkeit, Korrosionsfehler in Rohrleitungen genau zu dimensionieren, kann zu fehlerhaften Integritätsstrategien mit fatalen Folgen führen, selbst wenn geeignete Prüfprozesse angewendet werden. Eine Unterschätzung oder Überschätzung der Fehlergröße führt einerseits zu Pipelineversagen und andererseits zu unnötigen Untersuchungen. In den letzten Jahren wurden verschiedene Strategien zur Fehlergrößenbestimmung basierend auf Signalen des magnetischen Streuflusses entwickelt. Die Industrie drängt jedoch weiterhin auf eine Verbesserung der Zuverlässigkeit durch diese Technik. In der vorliegenden Arbeit werden Kalibrierkurven für die Rekonstruktion von Fehlstellen basierend auf Signalen des magnetischen Streuflusses beschrieben. Eine gründliche Untersuchung der verschiedenen Einflussparameter ermöglicht die Beziehungen zwischen den Dimensionen der Fehlstellen und Signalmerkmalen des magnetischen Streuflusses zu verstehen. Die Methodik dieser Forschung umfasst theoretische, numerische und experimentelle Bewertungen, die zur Entwicklung eines zuverlässigen dreidimensionalen Modells führen. Kalibrierkurven werden sowohl für Innen- als auch für Außenfehler angegeben. Solche Kurven ermöglichen die genaue Ermittlung der Fehlstellenlänge und -tiefe anhand der Signallänge und -amplitude. Die Ergebnisse, die in dieser Studie für Einzelfehler gewonnen wurden können verwendet werden, um Untersuchungen an benachbarten Fehlstellen durchzuführen, bei denen sich die Signale des magnetischen Streuflusses überlagern

Economic Fluctuations, Child Mortality and Policy Considerations in the Least Developed Countries

Between 1990 and 2010 child mortality decreased in general terms in the Least Developed Countries (LDCs), although the differences between countries over time are significant. This paper examines the relationship between short-term economic fluctuations and changes in child mortality in the LDCs during the period 1990-2010. Unlike other studies, we consider a large group of LDCs and provide empirical evidence of the asymmetrical effects of variations in Gross Domestic Product per capita on the evolution of child mortality rate in periods of economic recession and expansion. The significance of said effects diminishes when other relevant socio-economic control variables are considered, and some development policy considerations are addressed in order to achieve the Millennium Development Goal 4 target

Postoperative pain and morphine consumption after ultrasound-guided femoral and sciatic combined nerve block versus neurostimulation for femoral and sciatic combined nerve block or neurostimulation for femoral nerve block in primary elective total knee arthroplasty.

Abstract Congreso XXXVII National Meeting of the Spanish Society of Pharmacology with guest society: The British Pharmacological SocietyBackground and Aims: Total knee arthroplasty injuries are extremely painful and merit prompt attention to adequate postoperative analgesia. We aim to compare femoral and sciatic ultrasound-guided combined nerve block vs. neurostimulation for femoral and sciatic combined nerve block or for femoral nerve block in postoperative pain in primary elective total knee prosthesis. Summary of work and outcomes: A three arms, prospective longitudinal study of patients having primary elective unilateral knee prosthesis and randomly assigned to catheter insertion guided by ultrasound or neurostimulation was done: 1) Ultrasound-guided femoral and sciatic combined nerve block (USFSCN) (N=15); 2) Neurostimulation for femoral and sciatic combined nerve block (NSFSCN) (N=17); 3) Neurostimulation for femoral nerve block (NSFN) (N=11). Total analgesia (morphine) consumption after 48 hours was the primary endpoint. The postoperative pain intensity (visual analogue pain scale (VAS)) at post-anaesthetic recovery unit (PARU), 6, 24, 48 h, and during movement and postoperative complications were secondary outcomes. Results and discussion: 43 patients (68.3±8 years old, 77% female) subjected to elective unilateral knee prosthesis were enrolled. There were no differences in the demographic, anaesthetic and surgical variables between groups. Pain intensity was lower in the USFSCN group compared with NSFSCN and NSFN during the first 48 h post-surgery (% of intense pain at PARU/6h/24h/48h): USFSCN 0.8/1.4/3.2/1.6; NSFSCN 5.6/8.3/7.5/3; NSFN 7.2/5.3/6.4/5.4. The average consumption of morphine within 48 h after surgery was similar in the groups USFSCN and NSFSCN (3 mg vs. 3.11 mg), and significantly lower than NSFN (4.19 mg) (p<0.05). And the number of complications was significantly lower in the USFSCN group compared with NSFSCN and NSFN during the first 48 h of postoperative. Conclusion: Ultrasound-guided femoral and sciatic combined nerve block presented better analgesia and was more safety than neurostimulation for femoral and sciatic combined nerve block or for femoral nerve block in primary elective total knee arthroplasty.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Polychaete abundance, biomass and diversity patterns at the Mid-Atlantic Ridge, North Atlantic Ocean

Peer reviewedPublisher PD

Evaluation of digital linearization techniques for PAs under 5G waveform operation in spectrum sharing scenarios

This project has been oriented to improve the efficiency and the linearization of power amplifiers (PA) with the combination of crest factor reduction (CFR) techniques and digital predistortion techniques (DPD). These techniques have been applied to Filter Bank Multi Carrier (FBMC) signals, which is one of the candidate modulations for future 5G systems. Since these signals are composed by a multicarrier modulation, they show a high Peak to Average Power Ratio (PAPR), that drive the RF amplifiers into saturation and thus cause distortion unless operation under excessive back-off is followed. The PAs are inefficient when they are operated far from the compression point (i.e. with a large back-off). These amplifiers are non-linear systems that add distortion to the signal. For this reason, we have employed the CFR techniques and DPD techniques to guarantee the linearization-efficiency trade off being required, thanks to the clipping of the signal peaks that cause non-linearities and the inversion of the non-linear response of the PA, that allow increasing the average power operation of the power amplifier. To validate the effectivity of these techniques, some simulation work has been conducted in Matlab and then the concepts have been evaluated in a real hardware environment. The results have show that these techniques can improve the communication systems of a base station (BS), given the fact that typical figures of merit such as the EVM or the ACPR of a base station transmitter that were not fulfilling the standard requirements, become significantly improved and fully compliant after applying the techniques. For FBMC signals with holes created to allocate LTE signals (primary system) in scenarios of spectral coexistence, we have also demonstrated the improvement of the primary system immunity to FBMC interference thanks to the digital linearization techniques (due to the enhanced Signal to Interference plus Noise Ratio or SINR increase)

Context-aware Assessment Using QR-codes

In this paper we present the implementation of a general mechanism to deliver tests based on mobile devices and matrix codes. The system is an extension of Siette, and has not been specifically developed for any subject matter. To evaluate the performance of the system and show some of its capabilities, we have developed a test for a second-year college course on Botany at the School of Forestry Engineering. Students were equipped with iPads and took an outdoor test on plant species identification. All students were able to take and complete the test in a reasonable time. Opinions expressed anonymously by the students in a survey about the usability of the system and the usefulness of the test were very favorable. We think that the application presented in this paper can broaden the applicability of automatic assessment techniques.The presentation of this work has been co-founded by the Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech