1,343 research outputs found
Efecto de un programa HIIT versus entrenamiento continuo extensivo en individuos inexpertos
El objetivo del presente estudio fue analizar el efecto de un entrenamiento interválico intensivo (HIIT) y compararlo con el efecto de un entrenamiento continuo extensivo (carrera continua) en las variables de peso corporal, % de masa grasa y VO2máx. 32 participantes sin experiencia previa (media ± DE: 22.37 ± 1.8 años de edad; 65.52 ± 11.98 kg de peso; 170.66 ± 9.95 cm de altura) fueron asignados de forma aleatoria a un grupo de entrenamiento HIIT o de carrera continua de tres sesiones semanales durante 10 semanas. Las sesiones de HIIT tuvieron una duración de 20-25 min, basándose en ejercicios funcionales de autocarga con una relación trabajo/descanso de 20/10 s. Las sesiones de carrera continua tuvieron una duración de 60 min sin sobrepasar el 70% del Vo2máx personal. Ambos grupos obtuvieron mejoras significativas (p < .05) en las variables de estudio: peso corporal, % graso y VO2máx. Sin embargo, las mejoras en el grupo HIIT fueron superiores en las tres variables, por lo que se muestra como un entrenamiento más eficaz y eficiente, en términos de volumen/tiempo total de práctica semanal, que el método continuo extensivo basado en la carrera continua
Efecte d’un programa HIIT versus entrenament continu extensiu en individus inexperts
L’objectiu del present estudi va ser analitzar l’efecte d’un entrenament intervàlic intensiu (HIIT) i comparar-lo amb l’efecte d’un entrenament continu extensiu (cursa contínua) en les variables de pes corporal, % de greix corporal i VO2màx. 32 participants sense experiència prèvia (mitjana ± DE: 22.37 ± 1.8 anys d’edat; 65.52 ± 11.98 kg de pes; 170.66 ± 9.95 cm d’altura) van ser assignats de forma aleatòria a un grup d’entrenament HIIT o de cursa contínua de tres sessions setmanals durant 10 setmanes. Les sessions d’HIIT van tenir una durada de 20-25 min, basant-se en exercicis funcionals d’autocàrrega amb una relació treball/descans de 20/10 s. Les sessions de cursa contínua van tenir una durada de 60 min sense sobrepassar el 70% del VO2màx. personal. Tots dos grups van obtenir millores significatives (p < .05) en les variables d’estudi: pes corporal, % de greix corporal i VO2màx. No obstant això, les millores en el grup HIIT van ser superiors en les tres variables, per la qual cosa es mostra com un entrenament més eficaç i eficient, en termes de volum/temps total de pràctica setmanal, que el mètode continu extensiu basat en la cursa contínua
El acceso al empleo de la población inmigrantre : cuestión controvertida bajo el principio de igualdad y no discriminación = The access to employment of the inmigrant population : a controversial question under the principle of equality and non discrimination
La realidad social en Europa sobre la que está construida el derecho a la no discriminación por razón de nacionalidad en el acceso al empleo, es el denominado mercado de trabajo europeo. Este derecho está asentado en un conjunto de normas entre las que destacan a nivel comunitario el Tratado de Funcionamiento de la Unión Europea, además de Directivas y Reglamentos que versan, como complemento, sobre la libre circulación de personas por todo el territorio de los Estados miembros, con libertad de residencia y de llevar a cabo una actividad laboral o profesional con amparo en la normativa. Dentro de nuestro Estado, existen otros ordenamientos jurídicos nacionales que prevén este principio de no discriminación ante ciudadanos foráneos, siendo norma central la Ley Orgánica 4/2000, de 11 de enero de 2000, sobre los derechos y las libertades con las que cuentan los extranjeros en España y como se integran estos socialmente. La transposición de la normativa europea sobre esta materia para incorporarla a nuestro ordenamiento interno, sumado a la abundante jurisprudencia a nivel comunitario durante décadas, ha dotado a todos los países de la Unión Europea de una fuerte homogeneidad en el asunto. En el presente trabajo analizaremos de modo breve y descriptivo la doctrina teórica, así como el entramado jurídico del Derecho Comunitario y la interrelación de sus normas en relación con el principio a no ser discriminado en el acceso al empleo por razón de nacionalidad entre los ciudadanos europeos. Centrando un análisis jurisprudencial final, referente a eventuales limitaciones acerca de si la realización de actividades propias de ciertas profesiones que puedan tener que ver con el ejercicio del poder público, están permitidas o no para este colectivo de personas y como los tribunales han respondido a las misma
A machine learning approach to pedestrian detection for autonomous vehicles using High-Definition 3D Range Data
This article describes an automated sensor-based system to detect pedestrians in an autonomous vehicle application. Although the vehicle is equipped with a broad set of sensors, the article focuses on the processing of the information generated by a Velodyne HDL-64E LIDAR sensor. The cloud of points generated by the sensor (more than 1 million points per revolution) is processed to detect pedestrians, by selecting cubic shapes and applying machine vision and machine learning algorithms to the XY, XZ, and YZ projections of the points contained in the cube. The work relates an exhaustive analysis of the performance of three different machine learning algorithms: k-Nearest Neighbours (kNN), Naïve Bayes classifier (NBC), and Support Vector Machine (SVM). These algorithms have been trained with 1931 samples. The final performance of the method, measured a real traffic scenery, which contained 16 pedestrians and 469 samples of non-pedestrians, shows sensitivity (81.2%), accuracy (96.2%) and specificity (96.8%).This work was partially supported by ViSelTR (ref. TIN2012-39279) and cDrone (ref. TIN2013-45920-R) projects of the Spanish Government, and the “Research Programme for Groups of Scientific Excellence at Region of Murcia” of the Seneca Foundation (Agency for Science and Technology of the Region of Murcia—19895/GERM/15). 3D LIDAR has been funded by UPCA13-3E-1929 infrastructure projects of the Spanish Government. Diego Alonso wishes to thank the Spanish Ministerio de Educación, Cultura y Deporte, Subprograma Estatal de Movilidad, Plan Estatal de Investigación Científica y Técnica y de Innovación 2013–2016 for grant CAS14/00238
Learning Bayesian network classifiers for multidimensional supervised classification problems by means of a multiobjective approach
A classical supervised classification task tries to predict a single class variable based on a data set composed of a set of labeled examples. However, in many real domains more than one variable could be considered as a class variable, so a generalization of the single-class classification problem to the simultaneous prediction of a set of class variables should be developed. This problem is called multi-dimensional supervised classification.
In this paper, we deal with the problem of learning Bayesian net work classifiers for multi-dimensional supervised classification problems. In order to do that, we have generalized the classical single-class Bayesian network classifier to the prediction of several class variables. In addition, we have defined new classification rules for probabilistic classifiers in multi-dimensional problems.
We present a learning approach following a multi-objective strategy which considers the accuracy of each class variable separately as the functions to optimize. The solution of the learning approach is a Pareto set of non-dominated multi-dimensional Bayesian network classifiers and their accuracies for the different class variables, so a decision maker can easily choose by hand the classifier that best suits the particular problem and domain
Experimental dataset on the tensile and compressive mechanical properties of plain Kraft and crepe papers used as insulation in power transformers after ageing in mineral oil
The solid insulation in the windings of power transformers, which generally consists of oil-impregnated thin paper, is one of the key elements for the performance and durability of these electrical machines. Insulation paper is subjected to static and dynamic forces of electromagnetic origin, in combination with high temperatures and chemical reactions, during the operating life of a power transformer. The mechanical properties of the cellulosic insulation are relevant parameters because its breakage could result in the electric failure of the transformer. Indeed, paper manufacturers usually provide values of the tensile strength and elongation at breakage of the insulating paper in its two principal material directions, the MD (machine direction) and CD (cross-direction). However, paper is a highly anisotropic material and its material properties evolve as the paper insulation ages. The paper insulation in an operating transformer is subjected to a multiaxial stress state field including compressive and shear stresses. This article reports experimental data on the tensile and compressive mechanical properties of two types of paper, plain Kraft and crepe paper, typically used as insulation in power transformers, under different ageing states (which were induced through accelerated thermal ageing and quantified by means of the degree of polymerisation). These data could be reused for several purposes. They can improve the current understanding of the mechanical response and degradation processes of the cellulosic insulation in power transformers, and give some reference values that can be compared with others obtained in the factory by manufacturers. In the field of engineering failure analysis, those values could be reused for the assessment of mechanical failure of paper materials used in power transformers, see [1]
A modification of the Norris failure criterion for the prediction of the mechanical failure of the aged paper insulation in the windings of a power transformer
The deterioration of the insulation in the windings of power transformers affects their lifespan. A commercial insulated Continuously Transposed Conductor (CTC) was studied experimentally, numerically and analytically. The purpose was to understand the mechanisms governing the mechanical failure of the insulating paper, and to achieve a criterion for predicting failure under different conditions. Samples of that insulated CTC were extracted from a coil and aged at 150∘C for different durations inside vessels filled with naphthenic oil. Then the degree of polymerisation and tensile, compressive and shear mechanical properties of the insulation were measured/estimated. Aged insulated CTC samples were subjected to three-point bending tests, producing deformations compatible with a short circuit, and the fractures in the insulation were analysed. The bending test over a CTC sample was simulated by means of a FEM Program. The Norris failure model, applicable to a lamina, was adapted to the studied insulation materials. The predictions of that failure criterion agreed with experimental observations
Mechanical behaviour of the cellulosic dielectric materials of windings in power transformers in operation
Power transformers are crucial elements in electrical systems, and the end of their useful life is commonly conditioned by the degradation of the cellulosic insulation materials inside them. These materials are subjected to elevated temperatures and mechanical stresses, generated by electrical solicitations which deform the copper conductors and subsequently the paper, and also to the chemical reactions which take place in the dielectric oil in which the paper is impregnated. In order to better understand the behaviour of cellulosic insulation, we have studied the previous bibliography analysing the mechanical behaviour of cellulosic materials. At present, there are no experimental results analysing how the paper responds to the deformation suffered by the copper conductor in a realistic situation. We have developed a simulation model describing the mechanical behaviour of a standardised copper conductor wrapped with four layers of dielectric paper, using ANSYS Workbench Static Structural, which will be compared with experimental results afterwards
Evaluación de la calidad percibida de los servicios deportivos en el ámbito universitario
The physical and psychological benefits provided by regular moderate physical activity have been evidenced in numerous studies. Spanish universities have echoed this, recently creating the Spanish Network of Healthy Universities, resulting in a decided addition to its range of services of physical activity programs aimed at promoting sport among members of the university community, thus contributing to the establishment of a healthy lifestyle. The progressive adaptation of sporting activities to the needs and motivations of users, optimization of resources, and even adherence to doing sport, largely depends on providing a quality service. It is therefore important to have valid and reliable instruments, which are also simple at the same time, so that those responsible for university sports services can appropriately monitor their operation, incorporating the users' perceptions of their management. This study tests a tool of only 10 items, obtaining very acceptable psychometric properties, which makes it a useful tool in practical terms
Middleware control systems design and analysis using message interpreted Petri Nets (MIPN)
Many distributed frameworks use a message-oriented middleware to interchange information among several independent distributed modules. Those modules make up complex systems implementing basic actions and reporting events about their state. This paper introduces the Message Interpreted Petri Net (MIPN) model to design, analyze, and execute the central control of these middleware systems. The MIPN is a new Petri net extension that adds message-based high-level information communications and hierarchic capabilities. It also contributes to the definition and study of new properties such as terminability for the hierarchy-wide analysis of a system. Special attention is given to the analyzability of the model. Useful relations between the individual properties of each MIPN and the global properties of a hierarchic MIPNs system are extracted through a mathematical analysis of the model. The goal is to analyze each net separately and then build up the properties of the whole system. This results in a great aid for the programmer and optimizes the development process. This paper also shows the actual integration of this new MIPN model in different robot control frameworks to design, analyze, execute, monitor, log, and debug tasks in such heterogeneous systems. Finally, some applications created with this framework in the fields of robotics, autonomous vehicles, and logistics are also presentedMinisterio de Ciencia e Innovación | Ref. EXP00139978CER-2021100
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