Search results for "ESA"
showing 10 items of 11914 documents
Fiumara d’Arte. La rifondazione di un territorio di confine
2008
Su Fiumara d’Arte molto è stato scritto e detto. Inoltre, assai più dicono all’occhio e alla mente le opere che ne costituiscono la sostanza - ‘vascelli’ naufraganti tra i lembi molli di un territorio di confine, teatro di acerbe contraddizioni e, tuttavia, scenario di struggente bellezza. Questa breve guida si propone di ripercorrere, tra le righe di ciò che il mondo intero oramai riconosce e sostiene, i luoghi e i tempi, le congiunture e le conseguenze, di un’iniziativa individuale libera e creativa e fortemente contrastata alle origini. L’intento è di verificarne, di là dal comprovato spessore artistico, un pregnante valore etico, fondamento di crescita culturale e civile, prima ancora c…
Etsuro Sotoo; José Manuel Almuzara, "Dalla pietra al maestro", Cantagalli, Siena 2007.
2011
I libri intervista sono di solito dei percorsi semplificati nei quali chi pone la domanda, sfronda o precisa laddove il protagonista tende a complicare o a lasciare alcuni concetti indefiniti. Anche se in modo diverso, non fa eccezione Dalla pietra al Maestro, perché all’itinerario lineare che porta Etsuro Sotoo, scultore giapponese a trasferirsi a Barcellona, dove lavorerà alla Sagrada Famila, si somma un percorso dai significati molto più profondi che Jose Manuel Almuzara, con abilità, fa emergere. Quali sono le possibili chiavi di lettura del libro? Motivo conduttore del testo è la conversione al cattolicesimo di Sotoo ma Almuzara giunge per gradi a questa verità, proponendo al lettore a…
Modelling and Analysis of Nonstationary Vehicle-to-Infrastructure Channels with Time-Variant Angles of Arrival
2018
In mobile radio channel modelling, it is generally assumed that the angles of arrival (AOAs) are independent of time. This assumption does not in general agree with real-world channels in which the AOAs vary with the position of a moving receiver. In this paper, we first present a mathematical model for the time-variant AOAs. This model serves as the basis for the development of two nonstationary multipath fading channels models for vehicle-to-infrastructure communications. The statistical properties of both channel models are analysed with emphasis on the time-dependent autocorrelation function (ACF), time-dependent mean Doppler shift, time-dependent Doppler spread, and the Wigner-Ville sp…
A Fast Imaging Technique Applied to 2D Electrical Resistivity Data
2014
A new technique is proposed to process 2D apparent resistivity datasets, in order to obtain a fast and contrasted resistivity image, useful for a rapid data check in field or as a starting model to constrain the inversion procedure. In the past some modifications to the back-projection algorithm, as well as the use of filtering techniques for the sensitivity matrix were proposed. An implementation of this technique is proposed here, considering a two-step approach. Initially a damped least squares solution is obtained after a full matrix inversion of the linearized geoelectrical problem. Furthermore, on the basis of the results, a subsequent filtering algorithm is applied to the Jacobian ma…
Dirichlet Boundary Value Problem for the Second Order Asymptotically Linear System
2016
We consider the second order system x′′=f(x) with the Dirichlet boundary conditions x(0)=0=x(1), where the vector field f∈C1(Rn,Rn) is asymptotically linear and f(0)=0. We provide the existence and multiplicity results using the vector field rotation theory.
New Objective Refraction Metric Based on Sphere Fitting to the Wavefront
2017
Purpose. To develop an objective refraction formula based on the ocular wavefront error (WFE) expressed in terms of Zernike coefficients and pupil radius, which would be an accurate predictor of subjective spherical equivalent (SE) for different pupil sizes.Methods. A sphere is fitted to the ocular wavefront at the center and at a variable distance,t. The optimal fitting distance,topt, is obtained empirically from a dataset of 308 eyes as a function of objective refraction pupil radius,r0, and used to define the formula of a new wavefront refraction metric (MTR). The metric is tested in another, independent dataset of 200 eyes.Results. For pupil radiir0≤2 mm, the new metric predicts the equ…
Localization Operators and an Uncertainty Principle for the Discrete Short Time Fourier Transform
2014
Localization operators in the discrete setting are used to obtain information on a signalffrom the knowledge on the support of its short time Fourier transform. In particular, the extremal functions of the uncertainty principle for the discrete short time Fourier transform are characterized and their connection with functions that generate a time-frequency basis is studied.
A neural network-based approach to determine FDTD eigenfunctions in quantum devices
2009
This article combines a Neural Network (NN) algorithm with the Finite Difference Time Domain (FDTD) technique to estimate the eigenfunctions in quantum devices. A NN based on the Least Mean Squares (LMS) algorithm is combined with the FDTD technique to provide a first approach to the confined states in quantum wires. The proposed technique is in good agreement with analytical results and is more efficient than FDTD combined with the Fourier Transform. This technique is used to cal- culate a numerical approximation to the eigenfunctions associated to quan- tum wire potentials. The performance and convergence of the proposed technique are also presented in this article. © 2009 Wiley Periodica…
Effect of raster resolution and polygon-conversion algorithm on landslide susceptibility mapping
2016
The choice of the proper resolution in landslide susceptibility mapping is a worth considering issue. If, on the one hand, a coarse spatial resolution may describe the terrain morphologic properties with low accuracy, on the other hand, at very fine resolutions, some of the DEM-derived morphometric factors may hold an excess of details. Moreover, the landslide inventory maps are represented throughout geospatial vector data structure, therefore a conversion procedure vector-to-raster is required.This work investigates the effects of raster resolution on the susceptibility mapping in conjunction with the use of different algorithms of vector-raster conversion. The Artificial Neural Network t…
The Use of Artificial Intelligence in Disaster Management - A Systematic Literature Review
2019
Whenever a disaster occurs, users in social media, sensors, cameras, satellites, and the like generate vast amounts of data. Emergency responders and victims use this data for situational awareness, decision-making, and safe evacuations. However, making sense of the generated information under time-bound situations is a challenging task as the amount of data can be significant, and there is a need for intelligent systems to analyze, process, and visualize it. With recent advancements in Artificial Intelligence (AI), numerous researchers have begun exploring AI, machine learning (ML), and deep learning (DL) techniques for big data analytics in managing disasters efficiently. This paper adopt…