Efficient and Accurate hybrid GO-Spectral Algorithm to Design Conformal Serrated-Edge Reflectors Operating as Collimators in Millimeter Wave Compact Ranges

This paper presents a hybrid analysis algorithm, which is used at Radiation Group (UPM) to carry out the design of a conformal serrated-edge reflector for the mm-Wave compact range UPM facility. Main features of this algorithm involve its capability of handling conformal serrated rim parabolic reflectors, accuracy and computational efficiency

Antenna Measurement System at 300 GHz for the Terasense Project

The aim of this paper is to introduce the design techniques used to develop the antenna measurement system for the Terasense Project. This project, funded by the Spanish Government, involves millimetre-wave systems design. One of these systems is an antenna measurement facility. The antenna measurement system operates in a banded range of frequency. The lower frequencies deal between 75–110 GHz (WR10 operation range) and the upper frequencies are set between 220–325 GHz (WR03). Among the different possible configurations, the reflector-based compact range is chosen. The quiet zone is generated by a serrated-edge reflector, fed by a low gain horn. In this paper we will focus on the reflector design. A serrations study is carried out and quiet zone acquisition results are obtained

D3-D5 theories with unquenched flavors

We construct the string duals of the defect theories generated when N_f flavor D5-branes intersect N_c color D3-branes along a 2+1 dimensional subspace. We work in the Veneziano limit in which N_c and N_f are large and N_f/N_c is fixed. By smearing the D5-branes, we find supergravity solutions that take into account the backreaction of the flavor branes and preserve two supercharges. When the flavors are massless the resulting metric displays an anisotropic Lifshitz-like scale invariance. The case of massive quarks is also considered.Comment: 29 pages, 1 figure; v2: references adde

Injuries and pathologies in beach volleyball players: A systematic review

The aim of this paper is to review the available literature published on injuries and pathology in beach volleyball. The databases consulted were the Web of Sciende and Pubmed. After establishing the criteria for selection and filtering, a total of 32 articles were selected. All items found can be classified into four research lines. First are the studies focused on specific injuries such as shoulder, shoveling, knee and foot. The second line of research focuses on the study of the incidence, prevalence and frequency of injuries of beach volleyball players, whereas the third line deals on infections reported in the literature produced by nematodes or fungi. Finally, the last line of research includes articles addressing different objectives related to health such as the effects of training programs related to injuries, influence of weather conditions on the players, as well as publications for validation of assessment instruments or develop of guidelines and protocols for the evaluation and diagnosis of injuries

Actividad de los bloqueadores durante el Campeonato de Europa Universitario de vóley playa

In this paper, we present a study of blocker’s activity in university beach volleyball players. A total of n=1166 blocking actions were analyzed from 24 European men's teams at the Ninth European Beach Volleyball Championship EUSA GAMES. The analysis of the videos was carried out using the free software program LongoMatch v.0.27. Statistical significance of the comparison of systems was calculated using the Z test to compare proportions. Results showed that blockaders do not have a leading role in the Direct Intervention (DI) of the ball (37%, p<0.001). The most blocking actions were Line Blocking (LB) (46.9%), Net Exits (NE) (21.1%) and Diagonal Blocking (DB) (18.1%). When comparing periods of points (F1: 1 to 7, F2: 8 to 14, F3: 15 to 21), statistical differences (p<0.001) where observed between periods F1 and F3 for the most used blocking actions: LB, NE and DB. Finally, similar efficiency values were observed for the most common blocking actions (29.3% for LB and 23.2% for DB). Higher efficiencies can be found in less common defensive actions, such as V Blocking (VB) (31.4%) and Fighting (F) (34.6%).En este artículo se presenta un estudio de la actividad del bloqueador en jugadores universitarios de voley playa. Fueron analizados un total de 1166 acciones de bloqueo de 24 equipos europeos masculinos durante el Noveno Campeonato Europeo de Voleibol de Playa EUSA GAMES. El análisis de los videos se llevó a cabo utilizando el programa de software libre LongoMatch v.0.27. La prueba estadística aplicada para la comparación de las proporciones fue la prueba Z. Los resultados mostraron que los bloqueadores no realizan una intervención directa (DI) de la pelota (37%, p <0,001) como acción principal defensiva. Las acciones de bloqueo más utilizadas fueron Bloqueo en Línea (LB) (46,9%), Salidas de Red (NE) (21,1%) y Bloqueo Diagonal (DB) (18,1%). Cuando se comparan periodos de puntos (F1: 1 a 7, F2: 8 a 14, F3: 15 a 21), se observan diferencias estadísticas (p <0,001) entre los períodos F1 y F3 para las acciones de bloqueo más utilizadas: LB, NE y DB. Finalmente, se observaron valores de eficiencia similares para las acciones de bloqueo más comunes (29,3% para LB y 23,2% para DB). Se pueden encontrar mayores eficacias en acciones defensivas menos comunes, como V Bloqueo (VB) (31,4%) y Lucha (F) (34,6%)

Transfer learning or design a custom CNN for tactile object recognition

International Workshop on Robotac: New Progress in Tactile Perception and Learning in RoboticsNovel tactile sensors allow treating pressure lectures as standard images due to its highresolution. Therefore, computer vision algorithms such as Convolutional Neural Networks (CNNs) can be used to identify objects in contact. In this work, a high-resolution tactile sensor has been attached to a robotic end-effector to identify objects in contact. Moreover, two CNNs-based approaches have been tested in an experiment of classification of pressure images. These methods include a transfer learning approach using a pre-trained CNN on an RGB images dataset and a custom-made CNN trained from scratch with tactile information. A comparative study of performance between them has been carried out.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Spanish project DPI2015-65186-R, the European Commission under grant agreement BES-2016-078237, the educational project PIE-118 of the University of Malag

Defensive systems during the Men’s European University Beach Volleyball Championship

The analysis of performance in beach volleyball should consider the development of the set or game systems in connection with successful completion. In this paper, we present a study of defensive system in university beach volleyball players in order to determine the evolution throughout the set and effectiveness in relation to the performance factors of the game. A total of n=937 blocking actions were analyzed by means of video recordings from 24 European men's teams from 16 different nationalities at the Ninth European Beach Volleyball Championship EUSA GAMES. The analysis of the videos was carried out using the free software program LongoMatch v.0.27 by an experienced observer. Reliability performed on the intra-observer analysis showed a margin of error lower than 5%. Both effectiveness of the game systems and frequency of winning and not winning points were annotated for each period of points. Statistical significance of the comparison of systems was calculated using the Z test to compare proportions. Results showed that the most widely used game system was 2:1 with 67.2% (n=630) with statistically significance (p<0.001). Regarding effectiveness, system 2:1 presented an efficiency of success of 30.8% (n=194), whereas system 1:2 presented a moderately low value of 25.7% (n=79). When comparing periods of points (F1:1 to 7, F2: 8 to 14, F3: 15 to 21), system 2:1 showed higher effectiveness than 1:2 for the last two periods F2 and F3. Finally, a decrease in unscored point actions was observed in both systems between periods F1 to F3 (59.63% for 1:2 and 45.35% for 2:1)

Motivación hacia la práctica del atletismo en la educación primaria en función de dos propuestas de enseñanza/aprendizaje

Esta investigación trata de comparar la motivación de niños y maestros tras la aplicación de un programa de 18 sesiones de iniciación hacia la práctica del atletismo con una metodología tradicional y otra alternativa. Para lo cuál, 3 maestros y 32 alumnos de cuarto de Educación Primaria han participado en un total de 9 entrevistas semiestructuradas grupales. Las principales conclusiones a las que se ha llegado tras el análisis de los textos mediante el programa Nudist Vivo, son que el enfoque Ludotécnico es una propuesta que destaca entre los niños por la diversión que genera y su percepción motivacional dirigida hacia la tarea, provocando un menor número de comportamientos inadecuados, mientras que los maestros perciben que esta propuesta no estimula el aprendizaje, y se sienten mucho más cómodos con el empleo de un enfoque tradicional y un clima motivacional de implicación al ego

Validity, reliability and usefulness of smartphone and kinovea motion analysis software for direct measurement of vertical jump height

Jumping is a simple exercise determined by several biomechanical and physiological factors. Measures of vertical jump height are common and easy to administer tests of lower limb muscle power that are carried out with several types of equipment. This study aimed to validate and address the usefulness of the combination of smartphone and computer-based applications (Smartphone-Kinovea) against a laboratory-based Motion Capture System. One hundred and twelve healthy adults performed three maximal-effort countermovement jumps each. Both instruments measured the heights of the 336 trials concurrently while tracking the excursion of the body center of gravity. The vertical velocity at take-off vto and the impulse J were computed with jump height h measures. Intraclass correlation coefficient (ICC) results indicated very high agreement for h and vto (0.985) and almost perfect agreement for J (0.997), and Cronbach's α=0.99. Low mean differences were observed between instruments for h: -0.22 ± 1.15 cm, vto: -0.01 ± 0.04 m/s, and J: -0.56 ± 2.92 Ns, all p1). Bland-Altman plots showed very low mean systematic bias ± random errors (-0.22 ± 2.25 cm; -0.01 ± 0.08 m/s; -0.56 ± 5.73 Ns), without association between their magnitudes (r2=0.005, r2=0.005, r2=0.001). Finally, very high to practically perfect correlation between isntruments were observed (r = 0.985; r = 0.986; r = 0.997). Our results suggest that the Smartphone-Kinovea method is a valid and reliable, low-cost instrument to monitor changes in jump performance in a healthy, active population diverse in gender and physical condition.This work was supported by the Vice-rectorate program of Research and Knowledge transfer for the Promotion of R&D at the University of Alicante (Ref. GRE18–19)