1,190 research outputs found
An advanced symbolic analyzer for the automatic generation of analog circuit design equations
A tool for symbolic analysis of analog integrated circuits is presented featuring accurate simplification, pole/zero extraction, and tools for parametric AC circuit characterization. The program, called ASAP, uses signal flowgraph methods and has been written in C for portability. In its current version, ASAP is able to deal with the complexity levels arising in typical analog building blocks when described by device-level models. The ASAP inputs and outputs, the architecture, and the graphical interface are discussed
Benchmarking Particle Filter Algorithms for Efficient Velodyne-Based Vehicle Localization
Keeping a vehicle well-localized within a prebuilt-map is at the core of any autonomous vehicle navigation system. In this work, we show that both standard SIR sampling and rejection-based optimal sampling are suitable for efficient (10 to 20 ms) real-time pose tracking without feature detection that is using raw point clouds from a 3D LiDAR. Motivated by the large amount of information captured by these sensors, we perform a systematic statistical analysis of how many points are actually required to reach an optimal ratio between efficiency and positioning accuracy. Furthermore, initialization from adverse conditions, e.g., poor GPS signal in urban canyons, we also identify the optimal particle filter settings required to ensure convergence. Our findings include that a decimation factor between 100 and 200 on incoming point clouds provides a large savings in computational cost with a negligible loss in localization accuracy for a VLP-16 scanner. Furthermore, an initial density of ∼2 particles/m 2 is required to achieve 100% convergence success for large-scale (∼100,000 m 2 ), outdoor global localization without any additional hint from GPS or magnetic field sensors. All implementations have been released as open-source software
Tool for fast mismatch analysis of analog circuits
A tool is presented that evaluates statistical deviations in performance characteristics of analog circuits, starting from statistical deviations in the technological parameters of MOS transistors. Performance is demonstrated via the analysis of a Miller OTA in two different configurations and a linearized CMOS transconductor. The CPU time is reduced by a factor of 25 to 90 with respect to conventional Monte Carlo simulation, while maintaining similar accuracy in the computations
Influence of Partial Soil Wetting on Water Relation Parameters of the Olive Tree
A drip versus pond irrigation experiment was carried out with 30-year-old ‘Manzanilla’ olive trees planted at 7 m 5 m in an orchard
in Southwest Spain. At the end of the dry season of 1998, we chose two dry-land trees, D1 and D2, and two drip-irrigated trees, I1 and I2. During
the experiments, the D1 and I1 trees were pond-irrigated, increasing the soil water content to around field capacity in the whole rootzone. The
D2 and I2 trees were drip-irrigated, remaining part of the rootzone in drying soil. The results showed that the ratio between the transpiration of
the pond-irrigated D1 tree and that of the drip-irrigated D2 tree (D1/D2 Ep) increased from an average of 0.88 before irrigation to 1.22 fourteen
days after the first water supply. For the I trees, I1/I2 Ep varied from 0.76 to 1.02 nine days after the I1 tree was pond-irrigated for the first time.
Transpiration, therefore, was restricted when using a drip irrigation system which, despite supplying enough water to cover the calculated crop
demand, affected a part of the rootzone only. During the drip versus pond irrigation experiment, the recovery of leaf water potential, stomatal
conductance and photosynthesis rate was greater and quicker in the pond-irrigated than in the drip-irrigated trees.– Influence de l’irrigation partielle du sol sur les paramètres des relations hydriques de l’olivier. Une comparaison de l’irrigation
goutte à goutte avec l’irrigation en cuvette a été conduite sur oliviers ‘Manzanilla’ âgés de 30 ans plantés à 7 m 5 m dans un verger du sud-ouest
de l’Espagne. À la fin de la saison sèche de 1998, nous avons choisi deux arbres sur sol sec, D1 et D2, et deux arbres sur sol irrigué au goutte
à goutte, I1 et I2. Durant les expériences, les arbres D1 et I1 ont été irrigués en cuvette, en augmentant la teneur en eau du sol jusqu’à la capacité
au champ dans toute la zone racinaire. Les arbres D2 et I2 ont été irrigués au goutte à goutte, laissant une partie de la zone racinaire dans un sol
se desséchant. Les résultats ont montré que le quotient entre la transpiration de l’arbre D1 irrigué en cuvette et celle de l’arbre D2 irrigué au
goutte à goutte (D1/D2 Ep) a augmenté à partir d’une moyenne de 0,88 avant irrigation jusqu’à 1,22 quatorze jours après le premier apport
d’eau. Pour les arbres I, I1/I2 Ep a varié entre 0,76 et 1,02 neuf jours après que l’arbre I1 ait été irrigué en cuvette pour la première fois. Par
conséquent, la transpiration était réduite quand on utilisait un système d’irrigation au goutte à goutte qui, malgré l’apport d’eau suffisant pour
couvrir les besoins potentiels des cultures, a affecté seulement une partie de la zone racinaire. Durant cette comparaison de l’irrigation goutte
à goutte et de l’irrigation en cuvette, la récupération de la teneur en eau des feuilles, de la conductance stomatique et du taux de photosynthèse
était supérieure et plus rapide pour les arbres irrigués en cuvette que pour ceux irrigués au goutte à goutte
Los docentes de la Generación Z y sus competencias digitales.
La mera presencia de recursos tecnológicos en los centros y las altas capacidades de los alumnos de la «Generación Tecnológica»
o «Generación Z», no son suficientes para desarrollar en los alumnos la competencia digital. La clave fundamental viene determinada
por las competencias tecnológicas y pedagógicas de los docentes. En este trabajo, se pretende analizar el nivel de competencias
en TIC de los profesores de Primaria y Secundaria estableciendo un marco competencial de referencia adaptado al
ámbito educativo español, utilizando como base los estándares establecidos por la UNESCO en el año 2008 y reformulados en
el año 2011. Para ello, se realizó un cuestionario que permitió establecer el perfil de formación docente en TIC del profesorado
de la muestra (80 colegios y 1.433 profesores de la Comunidad de Madrid), para estudiar las características del profesorado mejor
formado para el desarrollo de la competencia digital que establece el Ministerio de Educación de España. Los resultados muestran
una alarmante diferencia entre las competencias que debieran tener los profesores para desarrollar la competencia digital en
sus alumnos y la que verdaderamente tienen. Las competencias digitales del profesorado son muy relevantes en el desarrollo de
procedimientos de aprendizaje que introduzcan las tecnologías como herramientas al servicio de la educación y este estudio nos
permitirá tomar decisiones en política de formación inicial y a lo largo de la carrera profesional del profesorado.The presence of technological resources in schools and the high performance of so-called «Technology Generation» or
«Generation Z» students are not enough to develop students’ digital competence. The primary key is determined by the technological
and pedagogical skills of teachers. In this paper, we intend to analyze the level of ICT skills of teachers in primary and
secondary establishing a competency framework adapted to the Spanish educational environment, using as a basis the standards
established by UNESCO in 2008 and reformulated in the year 2011. For this purpose, a questionnaire was done to show the
profile of ICT teacher training faculty of the sample (80 schools and 1,433 teachers in the Community of Madrid) to study the
characteristics of better training for the development of teachers was conducted the digital jurisdiction of the Ministry of Education
of Spain. The study results show a significant difference between optimal ICT skills and the low skills that teachers really have
to develop learning activities with technological tools for their students. Teachers’ digital skills are very important in the development
of learning processes to introduce technologies as tools in the service of education, and this study will allow us to make decisions
in policy formation and throughout early career teachers.post-print792 K
The Influence of the Social Context on Motivation towards the Practice of Physical Activity and the Intention to be Physically Active
According toWHOdata, only around 20% of adolescents participate in physical activity (PA)
during their free time. The social context can act as a support for adolescents to do PA, given the e ect
that both parents, friends and teachers have on young people’s behaviour owing to the large amount
of time and influence they have on them. Therefore, the aim of this study is to analyse the role of the
social context on adolescents’ motivation to practise PA and their intention to be physically active.
This study involved the participation of students in compulsory and post-compulsory secondary
education. Several statistical analyses were performed, including three confirmatory factorial analyses
of the scales and a structural equations model that explains the causal relationships between the
variables. The results showed how support for autonomy in the social context positively predicts
autonomous motivation, whereas the psychological control of the social context negatively predicts
it. Autonomous motivation positively predicted intent, attitude, behavioural control and subjective
norms, and consequently, the practice of physical activity. In short, the study showed how the
three validated scales have adequate goodness-of-fit indices while the structural equations model
demonstrated the influence of the social context on the student’s motivational processes and the
adoption of active life habits
Global design of analog cells using statistical optimization techniques
We present a methodology for automated sizing of analog cells using statistical optimization in a simulation based approach. This methodology enables us to design complex analog cells from scratch within reasonable CPU time. Three different specification types are covered: strong constraints on the electrical performance of the cells, weak constraints on this performance, and design objectives. A mathematical cost function is proposed and a bunch of heuristics is given to increase accuracy and reduce CPU time to minimize the cost function. A technique is also presented to yield designs with reduced variability in the performance parameters, under random variations of the transistor technological parameters. Several CMOS analog cells with complexity levels up to 48 transistors are designed for illustration. Measurements from fabricated prototypes demonstrate the suitability of the proposed methodology
Social networking and microblogging: educational innovation in higher education
Cada día nacen nuevos sitios web destinados a crear y gestionar redes sociales, a crear grupos o comunidades, a mantener el contacto online con personas conocidas o con los conocidos de estos últimos, a compartir conocimiento, experiencias, música, fotografías, entre otros. Estamos viviendo un gran fenómeno social que está revolucionando la manera de comunicarse y de interactuar con los demás, puesto que se están originando nuevas formas de interacción social, hasta ahora jamás producidas, donde se desencadena una red de contactos e intercambio virtual y dinámico entre personas, grupos e instituciones que tienen intereses y necesidades comunes (Bettinson, 2009; Espuny et al., 2011). Este fenómeno es provocado principalmente por las llamadas «redes sociales virtuales y el microblogging». Pero, ¿qué son exactamente las redes sociales virtuales?, ¿qué las diferencia de las redes sociales meramente físicas?, ¿qué ventajas e inconvenientes puede conllevar su uso? y por supuesto, ¿cómo podemos aprovechar esas ventajas en los diferentes contextos formativos?. En este artículo se presentan distintas experiencias educativas realizadas por tres docentes de la Facultad de Formación del Profesorado de la Universidad de Extremadura, que puede servir como marco de reflexión y acción en la praxis e innovación educativa que pueden servir de reflexión, ejemplo o de punto de partida para todo aquel docente que busque en las redes sociales la oportunidad de innovar en su práctica educativa.Nowadays, new websites are created everyday. They are devoted to creating and managing social networks, create groups or communities, to keep online contact with acquaintances and the acquaintances of the latter, to share knowledge, experiences, music, photographs, etc. Thus, we are witnessing a great social phenomenon, a true revolution in the way of communicating and interacting with others, owing to the fact that new modes of social interaction, unknown before, are emerging, whereby new networks of contacts and virtual and dynamic exchanges surge among individuals, groups and institutions sharing common interests and needs (Bettinson, 2009; Espuny et al., 2011). This phenomenon is mainly triggered by the so called «virtual social networking and microblogging». However, what exactly are virtual social networks?; what is it that differenciate them from mere physical social networks?; what are the advantages and drawbacks their use can entail?, and above all, how can we make the most of them in regular and virtual teaching? Hereby will be explained different teaching experiences carried out by three lecturers from the University of Extremadura that should serve as a reflexion, experience sharing or starting point for those practitioners that are looking for innovation in the social networking area
Las metáforas políticas en los discursos parlamentarios del presidente Pedro Sánchez durante el confinamiento
This article analyzes the political metaphors used by President Pedro Sánchez, in his parliamentary speeches during lockdown in Spain, between March and June 2020. This context of globalized health crisis favored specific uses of political language in various national contexts. This study develops a qualitative methodology that seeks to classify metaphors according to their object and link them with the communicative priorities of each parliamentary speech. The article is theoretically based on the structural metaphor conceived by Lakoff and Johnson to find those unnoticed metaphors in everyday life and on Wittgenstein’s theory of language games. These theories allow us to identify how the use of rhetorical figures it serves to create dominant narratives. This article shows that metaphors used by Pedro Sánchez served three purposes: to legitimize the government’s actions, to inform the population in easily understandable terms and, lastly, to help to retain the political power.En este artículo se analizan las metáforas políticas utilizadas por el presidente Pedro Sánchez, en los discursos parlamentarios durante el confinamiento en España, entre marzo y junio de 2020. Este fue un contexto de crisis sanitaria globalizada que favoreció usos específicos del lenguaje político en diversos contextos nacionales. Este estudio desarrolla una metodología cualitativa que busca clasificar las metáforas según su objeto y enlazarlas con las prioridades comunicativas de cada discurso parlamentario. El artículo se fundamenta teóricamente en la metáfora estructural concebida por Lakoff y Johnson para encontrar las metáforas inadvertidas, y en la teoría de juegos del lenguaje de Wittgenstein. Ello permite entender cómo el empleo de figuras retóricas sirve para crear narrativas dominantes. Las conclusiones muestran que las metáforas empleadas por Pedro Sánchez responden a un triple objetivo: legitimar la acción del gobierno, informar en términos comprensibles a la población y, por último, favorecer el mantenimiento del poder político
Sistema combinado de calefacción y enriquecimiento carbónico a partir de biomasa
Número de publicación: ES2514090 A1 (27.10.2014) También publicado como: ES2514090 B1 (10.08.2015) Número de Solicitud: Consulta de Expedientes OEPM (C.E.O.) P201300422 (26.04.2013)La invención consiste en un proceso de aprovechamiento energético de biomasa vegetal que permite aprovechar el calor contenido en la biomasa para la calefacción de cultivos protegidos y/o sistemas, así como recuperar el CO2 contenido en los gases de combustión generados para ser utilizado en sistemas de enriquecimiento carbónico de atmósferas, como en los cultivos intensivos bajo plástico. Se han establecido las condiciones de operación adecuadas del proceso de forma que se optimiza su eficiencia. El empleo de este sistema en cultivos bajo plástico permite conseguir una importante mejora en el crecimiento de los cultivos. Este proceso consigue aprovechar el 80% de la energía contenida en la biomasa para calefacción, así como retener el 99% del CO2 generado con un consumo energético inferior a 100 kJ/kgCO2, permitiendo además liberar este CO2 a demanda para el enriquecimiento carbónico de atmósferas.Universidad de Almerí
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