Ultra-Broadband Directional Couplers Using Microstrip with Dielectric Overlay in Millimeter-Wave Band

Nowadays, millimeter-wave systems are being a key factor to develop wide band applications. In this paper, a directional coupler in millimeter-wave band using dielectric overlay is presented. This leads us to technology aspects, in directional coupler design, are key points to achieve the proper response of the circuit. The coupler proposed in this paper covers the 15-45 GHz band and its response has 15-dB coupling-level, 1-dB coupling-ripple and a reflection coefficient better than 10 dB

One-on-one situation decision-making according to equipment in youth basketball

The goal was to verify with which ball participants improved the attackers' decisions in one-on-one game situations during youth basketball. Participants were 88 9- to 11-year-old boys from eight teams. We organized a three-day tournament consisting of 12 games, in which four games were played with each ball among all the teams. The balls differed only in their weight (440 g, 485 g, 540 g). The videos filmed were observed by two observers trained. The dependent variables were number of decisions, appropriate decisions, inappropriate decisions and ratio of correct to incorrect decisions, in the one-on-one situation. Participants made more decisions, and more correct (but not incorrect) decisions, when using the 440 -g rather than the regulation and 540 -g ball. This view requires that youth coaches act as a facilitator of learning, designing practice context according the objective evidence.This research was supported by Fundación Séneca: Agencia Regional de Ciencia y Tecnología de la Región de Murcia: 15349/PHCS/1

Effect of two different forms of three-point line on game actions on girls’ mini-basketball

The aim of this study was to compare two different designs of the three-point line to analyze which one allows for a higher frequency of motor actions that, according to the bibliography, should be strengthened when including a three-point line in youth basketball. In the first of two championships, female mini-basketball players (n=67) played with a three-point line delimited by the free throw lane, while during the second one, they played with a rectangular three-point line. Four observers were trained. The reliability reached values between .90 and .98. The Mann-Whitney U Test was used to determine if there were significant differences among the averages of the compared variable. When participants used the three-point line delimited by the free throw lane, there were increases in the percentage of ball possessions that ended in a shot (U=1280785, Z=-3.827, p=.000), that ended in shots from zones A (U=1286321, Z=-3.531, p=.000) and C (U=1356614, Z = -2.182, p = .029), in standard shots (U=1294771, Z=-3.269, p=.001), in hook shots (U=1358526, Z=-3.176, p=.001), in three-point shot attempts (U=1314902, Z=-6.600, p=.000), and in successful three-point shots (U=1355201, Z=-3.888, p=.000). This study confirms the necessity of consulting with analysts before introducing and modifying a rule in spor

Distances and shooting zones as a function of mass of basketball among 9- to 11- year-old male players

The goal of this study was to analyse with which ball the participants attempted a greater number of shots and achieved more successful shots from distances greater than four meters and from positions outside the free throw lane. The 54 participants included 9 to 11-year-old children from six basketball teams. Three situations were established in which the participants played four games with each of the following balls: a regulation ball (485g, 69-71cm); a ball of smaller mass (440g, 69-71cm); and a ball of greater mass (540g, 69-71cm). The procedures that followed included: defining the variables; instructing the observers and obtaining reliability; monitoring the properties of the ball and filming the games; and recording the data from the observation. Kruskal-Wallis H was applied to determine in which categories there were significant differences. Then, post-hoc comparisons were performed with Mann-Whitney’s U to determine with which balls these differences occurred. The results did not reflect any statistically significant differences for attempted and successful shots from any distance and shooting zone with any ball. Shots were attempted with greatest frequency from a distance of less than four meters and from inside the free throw lane with all three balls

Sobre textos clásicos y pintura : algunas observaciones

En las páginas que siguen se discurre sobre la proximidad entre arte y literatura, y también entre semiología y fIlología como método, y se acude, sobre todo, al apoyo didáctico que estas concomitancias suponen para la impartición de la cultura clásica. Hay algo de reflexión y algo de método, pero de una y otro, sólo unas pincelada

Las redes inalámbricas de área local ("Wi-Fi") en la FCC y el CNAF

En los últimos años, las Redes Inalámbricas de Área Local (WLAN, Wireless Local Área Networks) basadas en el estándar IEEE (802.11 [1] y sus derivados ñan conseguido unos altos niveles de implantación y desbordar el ámbito de aplicaciones y servicios para los que fueron inicialmente concebidas. De hecho, que se ñan convertido en un fenómeno tecnológico

Assessing the effect of public subsidies on firm R&D investment: a survey

This survey examines the empirical literature on the relationship between public R&D subsidies and private R&D investment over the past five decades. The survey reveals a considerable heterogeneity of empirical results that cannot be explained fully by methodological issues. We aim to provide further explanations of the possible causes of that heterogeneity. In particular, we emphasise a set of issues that, in our view, are critical to understanding the potential effect of public R&D subsidies on private R&D spending. Special attention is paid to the dynamic aspects and composition of firm R&D, the constraints faced by the firm (such as financial constraints), and the amount and source of public subsidies. None of these issues have been investigated in depth. We formulate a set of research assumptions to guide future empirical research in this field.This study was financially supported by the Spanish Ministry of Science and Innovation (Projects: ECO2012-31358, ECO2012-36775, and ECO2010-21473), Cátedra Iberdrola for Research in Business Management and Organization at Rey Juan Carlos University, and UNIR Research at International University of La RiojaPublicad

Measurement of Distributed Antenna Systems at 2.4 GHz in a Realistic Subway Tunnel Environment.

Accurate characterization of the radio channel in tunnels is of great importance for new signaling and train control communications systems. To model this environment, measurements have been taken at 2.4 GHz in a real environment in Madrid subway. The measurements were carried out with four base station transmitters installed in a 2-km tunnel and using a mobile receiver installed on a standard train. First, with an optimum antenna configuration, all the propagation characteristics of a complex subway environment, including near shadowing, path loss,shadow fading, fast fading, level crossing rate (LCR), and average fade duration (AFD), have been measured and computed. Thereafter, comparisons of propagation characteristics in a double-track tunnel (9.8-m width) and a single-track tunnel (4.8-m width) have been made. Finally, all the measurement results have been shown in a complete table for accurate statistical modeling