3,112 research outputs found
LTE signal propagation in a maritime environment: Validation of a hybrid MoM-ray tracing prediction method
No full textThe present work shows how we were able to deploy a hybrid Method of Moments (MoM) - Ray Tracing electromagnetic approach to predict the measured power over a Long Term Evolution (LTE) radio link over the sea during two different measurement campaigns. Empirical models and pure ray-tracing code by themselves were not able to accurately reproduce the measured features, which were found to be caused by the receiving antenna interactions with the ship metallic structure. The correct result was obtained through a hybrid approach which combines the far field of the antenna and its surroundings. This approach could prove beneficial in critical applications where a precise estimation of received power and coverage range is desirable
Hybridizing ray tracing and method of moments for over-the-sea prediction of LTE signal
No full textThis paper presents the results of a measurements campaign performed on a dedicated 1.8 GHz Long Term Evolution (LTE) system along a 47 kilometers path in the maritime area near Livorno, Italy. The comparison between the measured Reference Signal Received Power (RSRP) and the predicted coherent power shows how a ray tracing technique is suitable for a reasonable estimation in a maritime environment. Moreover, we show how it is possible to combine Ray Tracing (RT) with a Method-of-Moments (MoM) model of the environment surrounding the receiver, obtaining a more accurate estimation of the data. Such an approach could prove beneficial in critical situations where a more detailed estimation is required, and empirical methods are insufficient
Wireless propagation modeling by using ray-tracing
No full textThe asymptotic high frequency techniques, based on the Geometrical Optics (GO), the Geometrical Theory of Diffraction (GTD), and its extension such as the Uniform Theory of Diffraction (UTD), can be used to study the propagation of wireless electromagnetic signals in complex environments. Indeed, at high frequencies, it is possible to use the ray concept to trace the paths followed by electromagnetic waves from the transmitting to the receiving antenna, and to calculate the attenuation suffered by virtue of its interaction with the obstacles present in its environment. After a brief overview of the evaluation of electromagnetic fields by using the GO and/or the GTD/UTD, the fundamental geometric concepts of the ray-tracing algorithms are presented. Next, some acceleration techniques, necessary to efficiently model wireless propagation in outdoor and indoor environments, are discussed. Furthermore, leveraging the fact that the ray-tracing algorithm provides all the data necessary for a complete characterization of wireless propagation, it is used to derive some important parameters such as Path Loss, Delay Spread, channel frequency and impulse response, Power Delay Profile and Spreading Function
A imagem de Alessandro Baricco no Brasil
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Estudos da Tradução, Florianópolis, 2013.Com a intenção de delinear o modo pelo qual o escritor italiano Alessandro Baricco se inseriu no sistema literário brasileiro e os caminhos percorridos pelos seus livros traduzidos, esta dissertação dá voz às experiências tradutórias de seus tradutores. A inserção de Bariccono Brasil tem seu início em 1997, através de uma proposição da Profa. Dra. Roberta Barni à editora Iluminuras da tradução de Oceano Mare. A partir daí, outras sete obras foram publicadas no Brasil, sendo três delas traduzidas por Roberta Barni e as outras quatro por quatro tradutores diferentes. De um lado, considera-se o tradutor como figura principal namediação entre culturas, e, de outro, se analisa a realidade desta figuradentro do sistema literário, sua invisibilidade, seus limites e o exercíciode sua profissão. A pesquisa conta, ainda, com críticas e resenhas referentes ao autor italiano publicadas em jornais consagrados no Brasil, considerando estas como parte constituinte da imagem de Baricco refletida em território nacional. Abstract : Intending to delineate the way the Italian writer Alessandro Baricco has been inserted in the Brazilian literary system and the paths his translated books have followed, this thesis gives voice to the translating experiences of his translators. Baricco's insertion in Brazil began in 1997, through a personal project of Dr. Roberta Barni, with her translation of Oceano Mare. Since then, seven other of his works have been published in Brazil, three of which were translated by Roberta Barni and the other four by four different translators. On the one hand,the translator is considered as the main figure in mediation betweencultures and, on the other, this figure's reality is analyzed within theliterary system: its invisibility, its limits and its professional practice. Criticisms and reviews of this Italian author published in well established Brazilian newspapers are also considered, with the understanding that they are part of Baricco's image reflected here
An Efficient Approach for the Fast Isolation Assessment of Co-located 5G Antennas
No full textDeployment plans of Base Stations depend on the maximum number of antennas that can be installed on the same infrastructure and their separation distances is strictly related to the isolation assessment. In fact, closely spaced antennas can lead to an increase in electromagnetic coupling with consequent degradation in the performance of the overall radio system. In this work, we propose a novel approach to speed up the calculation of isolation value among co-located antennas on the same 5G cell tower; the methodology here presented allows us to overcome the current limitations of commercial software or long measurement campaigns
An Efficient Method for Fast Isolation Assessment of Base Station Antennas
No full textThe antenna isolation assessment is an important aspect for the network planning. In fact, it influences the number of antennas that can be installed on the same infrastructure and the performance of the communication system. In this work we propose an innovative method for the isolation assessment among the antennas of 5G Base Station; it allows to overcome the limitations of the commercial software and long measurements campaign
Channel characterization of wireless systems on board of ships by using an efficient ray-tracing
No full textLa maturità di Alessandro Fei del Barbiere, in bilico tra Maniera e Riforma
No full textThis article studies the mature career of the Florentine painter Alessandro Fei del Barbiere (1537-1592), beginning with the rediscovery of the 'Ascension' altarpiece formerly in the Albizi Chapel in the destroyed church of San Pier Maggiore, Florence. Studying this painting and others recorded in 1584 by the biographer Raffaello Borghini, such as the two altarpieces for Santa Maria delle Grazie and the Madonna dell'Umiltà in Pistoia, the author reconstructs a body of works showing how in the 1580s Fei gradually went beyond the archaic style of his apprenticeship - he had been trained by Ridolfo del Ghirlandaio and Pierfrancesco Foschi, but was also marked by the Maniera of Vasari - evolving towards naturalism in both mimesis and pictorial handling. In Florence, his development partly parallels that of Santi di Tito and his circle, but Fei was also influenced by a probable sojourn during the early part of that decade in Rome, where he could have been inspired by Girolamo Muziano and the painters working for Pope Gregory XIII. Among other proposals, the author suggests that the artist was responsible for decorating the chancel of Fiesole Cathedral (c. 1584-1589), which consisted of an altarpiece, only rarely discussed by scholars, and a cycle of frescoes hitherto attributed to Nicodemo Ferrucci
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