Flexible functional split and fronthaul delay: a queuing-based model

We study the delay over virtual RAN (vRAN) topologies, entailing base stations that are divided into centralized and distributed units, as well as the packet-switched fronthaul network that connects them. We consider the use of flexible functional split, where the functions that are executed at each of these two entities can be dynamically shifted. We propose a queuing-based model, which is able to precisely mimic the behavior of such nodes, and we validate it by means of extensive simulations. We also exploit Jackson Networks theory to establish the end-to-end delay over the fronthaul network, allowing us to assess the impact of having different networking policies and conditions (for instance, background traffic or heterogeneous technologies). Thanks to the simulator we can also broaden the analysis, by studying the delay variability. In addition, we conduct an in-depth analysis of the performance exhibited by a realistic network setup, whose particular characteristics might hinder the services performance, due to the longer dwell times at each split configuration. The results evince the validity of the proposed model, even under realistic conditions. We show that it might not be enough to guarantee an average stable operation of the centralized/distributed units, but the traffic load should remain below the slowest service rate, to avoid reaching unacceptable delays. An increase of >100× is observed in the delay, using the realistic network setup, when these conditions do not hold.This work was supported in part by the Spanish Government, Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional (MINECO-FEDER), through the Project FIERCE: Future Internet Enabled Resilient smart CitiEs under Grant RTI2018-093475-AI00; and in part by the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Program (FlexNets) under Grant 64715

ANÁLISIS DE LA POLÍTICA PÚBLICA HACIA LA HABITABILIDAD DE LA VIVIENDA EN MÉXICO

En el presente trabajo, desde la perspectiva de la bioética, se analiza el papel que han tenido las políticas públicas en la habitabilidad de la vivienda, y cuál es el abordaje que la administración pública en México ha desplegado en relación a ésta. En respuesta a los derechos individuales, referidos al bienestar humano y una vivienda digna establecidos en la Constitución Política de los Estados UnidosMexicanos (CPEUM, 1983, art. 4). Se partió de un análisis crítico de los planes nacionales de vivienda, desde 1990 hasta la actualidad, así como del marco jurídico específico que regula la politica habitacional en México, y el instrumento normativo que opera el organismo responsable de ella, identificando cómo se ha perfilado la actuación del sector vivienda, y la planeación de las acciones correspondientes, con el fin de reconocer su impacto en la producción del espacio habitacional. A partir de este análisis se identificó la forma en la que la Comisión Nacional de Vivienda (CONAVI) y la Ley Federal de Vivienda (LFV), conceptualizan la habitabilidad y la forma en la que se ha considerado ésta como parte de la política habitacional en el país. Derivado de lo anterior, se perfila un conjunto de estrategias de política pública que consideran los aspectos relacionados con la habitabilidad que se deberían abordar para impulsar una política habitacional sostenible económica y ambientalmente, a la vez que enfoque su atención en las necesidades socioculturales de las personas y en la aptitud de su hábitat para responder a sus necesidades cualitativas, lo cual derivaría en un fomento a su calidad de vida

El tranvía de Zaragoza: ¿principal propulsor del transporte sostenible en la ciudad?

La implantación del tranvía en Zaragoza ha supuesto sin duda muchos cambios en la ciudad afectando de forma considerable al transporte y con ello a los ciudadanos. Este trabajo tiene como objetivo valorar cómo ha afectado dicho proyecto en la forma de desplazarse en la ciudad, y comprobar en qué medida está contribuyendo a la mejora de la sostenibilidad del transporte en Zaragoza. Para llegar a ese objetivo se ha analizado el tranvía de Zaragoza (usuarios y características), cómo ha afectado a los distintos medios de transporte: movilidad a pie y bici, vehículo privado y autobuses urbanos y las emisiones e inmisiones registradas. Para la movilidad a pie se ha tenido en cuenta las secciones de las calles más importantes por donde pasa el tranvía valorando si se han ampliado las anchuras de las aceras, y en qué medida con los datos estadísticos disponibles, se ha variado el total de desplazamientos a pie. La movilidad en bici se ha dividido en dos partes: longitud de carriles bici y uso de la bicicleta pública. La longitud de los carriles bici se ha estudiado para saber el grado de afección que ha tenido el tranvía en la construcción de los mismos. El uso, para saber si ha sido satisfactorio el fomento de la bicicleta. Remarcar que solo se ha podido conocer estadísticas de la bicicleta pública. En cuanto a los autobuses urbanos, se han examinado los kilómetros recorridos, usuarios y el IPK (número de usuarios por kilómetro recorrido) para conocer el grado de utilización y eficiencia de los mismos. Estos datos se compararán posteriormente con el tranvía. Respecto al tráfico rodado, se estudian las intensidades medias diarias, capacidad y congestión de las calles paralelas y perpendiculares al trazado del mismo. Por último se calcularán las emisiones producidas por el tráfico rodado, autobuses urbanos y tranvía, comprobando el balance de emisiones antes y después de la implantación del tranvía, pudiendo obtener una representación de las inmisiones recogidas en las estaciones Centro y Renovales

Black-box and surrogate optimization for tuning spiking neural models of striatum plasticity

The basal ganglia (BG) is a brain structure that has long been proposed to play an essential role in action selection, and theoretical models of spiking neurons have tried to explain how the BG solves this problem. A recently proposed functional and biologically inspired network model of the striatum(an important nucleus of the BG) is based on spike-timing-dependent eligibility (STDE) and captured important experimental features of this nucleus. The model can recognize complex input patterns and consistently choose rewarded actions to respond to such sensory inputs. However, model tuning is challenging due to two main reasons. The first is the expert knowledge required, resulting in tedious and potentially biased trial-and-error procedures. The second is the computational cost of assessing model configurations (approximately 1.78 h per evaluation). This study addresses the model tuning problem through numerical optimization. Considering the cost of assessing solutions, the selected methods stand out due to their low requirements for solution evaluations and compatibility with high-performance computing. They are the SurrogateOpt solver of Matlab and the RBFOpt library, both based on radial basis function approximations, and DIRECT-GL, an enhanced version of the widespread black-box optimizer DIRECT. Besides, a parallel random search serves as a baseline reference of the outcome of opting for sophisticatedmethods. SurrogateOpt turns out to be the best option for tuning this kind of model. It outperforms, on average, the quality of the configuration found by an expert and works significantly faster and autonomously. RBFOpt and the randomsearch share the second position, but their average results are belowthe option found by hand. Finally, DIRECT-GL follows this line becoming the worst-performing method.R+D+i projects - MCIN/AEI RTI2018-095993-B-I00 PID2021-123278OB-I00European CommissionJunta de Andalucia P18-RT-1193University of Almeria UAL18-TIC-A020-BAndalusian governmentSpanish Grant INTSENSO MICINN-FEDER-PID2019-109991GB-I00Regional grants Junta Andalucia-FEDER CEREBIO P18-FR-2378European Commission 945539Spanish Government FPU17/0443

Basketball retirement : process and outcomes

Retirement from a sport career represents a turning point in the life of a sportsman. The aim of this study was to determine how the process of withdrawal of professional basketball players and the factors that influence it. Using a qualitative methodology, semi-structured interviews were conducted with 6 professional players focusing on their experiences during the process. Analysis of the interviews revealed the need to treat this process from a multidimensional perspective, as several factors interact. The results obtained show that the players assign great importance to the economic, academic and adjustment difficulties. Consequently, we discuss the need for specific assistance programs for these athletes, regardless of their previous professional level

Aumento de la eficiencia por mejora genética

PublishedCapítulo

Analysis of a bidirecctional coupled-inductor Cuk converter operating in sliding mode

Analytic models for a bidirectional coupled-inductor Cuk converter operating in sliding mode are described. Using a linear combination of the converter four state variable errors as a general switching surface, the expression for the equivalent control is derived and the coordinates of the equilibrium point are obtained. Particular cases of the general switching surface are subsequently analyzed in detail: 1) surfaces for ideal line regulation, 2) surfaces for ideal load regulation, and 3) surfaces for hysteretic current control. Simulation results verifying the analytical predictions are presented.Peer Reviewe

Aplicación del modelo Flipped Classroom y las TIC en las asignaturas de la materia de Ciencias Biológicas del Grado en Ciencias de la Actividad Física y del Deporte.

El presente proyecto pretende mejorar la calidad docente y, por ende, mejorar los resultados académicos de las asignaturas que forman la Materia de Ciencias Biológicas (Anatomía Humana, Fisiología del Deporte y Biomecánica del Deporte), encuadradas dentro del Módulo de Ciencias Básicas y contempladas en la estructura del Grado en Ciencias de la Actividad Física y del Deporte, según su memoria aprobada en el 2009 (Resolución de 13 de noviembre de 2009, pag. 732) y verificada en febrero de 2016 (expediente Nº: 1250/2009 ID título: 2500909). Cabe destacar que las asignaturas de la Materia están consideradas como créditos de Formación Básica y son impartidas en primer y segundo curso de la titulación, teniendo una carga crediticia total de 16 créditos ECTS. Para ello, el presente proyecto pretende utilizar las Tecnologías de la Información y de la Comunicación (TIC) junto con un nuevo abordaje educativo denominado Flipped Classroom (FC), como medios para mejorar y facilitar la adquisición de las competencias clave de las asignaturas que comprenden la Materia de Ciencias Biológicas. Para el desarrollo del proyecto, se pretende generar video-tutoriales, que se pondrán a disposición de los alumnos previamente a las clases teóricas en aula con la intención de involucrar a los alumnos en el proceso de aprendizaje. Igualmente, se diseñarán herramientas de autoevaluación de los contenidos visualizados por los alumnos.Actividad Física y Deport

Tuning compilations by multi-objective optimization: Application to Apache web server

Modern compilers present a great and ever increasing number of options which can modify the features and behavior of a compiled program. Many of these options are often wasted due to the required comprehensive knowledge about both the underlying architecture and the internal processes of the compiler. In this context, it is usual, not having a single design goal but a more complex set of objectives. In addition, the dependencies between different goals are difficult to be a priori inferred. This paper proposes a strategy for tuning the compilation of any given application. This is accomplished by using an automatic variation of the compilation options by means of multi-objective optimization and evolutionary computation commanded by the NSGA-II algorithm. This allows finding compilation options that simultaneously optimize different objectives. The advantages of our proposal are illustrated by means of a case study based on the well-known Apache web server. Our strategy has demonstrated an ability to find improvements up to 7.5% and up to 27% in context switches and L2 cache misses, respectively, and also discovers the most important bottlenecks involved in the application performance

Analysis of Samples Cleaning Methods Prior to Hydrogen Content Determination in Steel

ABSTRACT: There are multiple references to sample cleaning methods prior to hydrogen content determination, or hydrogen spectroscopy analysis, but there is still no unified criteria; different authors use their own "know-how" to perform this task. The aim of this paper is to solve, or at least clarify, this issue. In this work, the most commonly used sample cleaning methods are compared. Then, five different methodologies are applied on certified hydrogen content calibration pins and on high strength steel concrete-prestressing strands and the three main situations regarding hydrogen content in the microstructural net (non-charged, charged, and charged and uncharged) are studied. It was concluded that the HCl solution C-3.5 cleaning method recommended by ASTM G1 introduces large amounts of hydrogen in the samples; but can be useful for eliminating superficial oxides if necessary. The rest of the methods had similar results; but the more complete ones that involve ultrasounds and last longer than 8 min are not appropriated when important diffusion may occur on the samples during their application. Simple methods that involve acetone or trichloroethylene and last around 1 min are preferable for almost all situations as these are faster, easier, and cheaper. As a final recommendation, as trichloroethylene is toxic, the simple acetone method is, in general, the most convenient one for regular hydrogen content analysis.This research was funded by the UNIVERSITY OF CANTABRIA by means of the “Proyectos Puente 2019” grant program. The APC was funded by papers reviews of the authors for MDPI