7,451 research outputs found
Brainstorming about the geometric structures in the Wolfram model of fundamental physics
In this essay, we explore the geometric structures involved in the Wolfram
model of fundamental physics. Furthermore, we propose some directions of
research aiming to get the bosons and fermions out of this framework
Review of Arte Escrita. Texto, imagen y género en el arte contemporáneo, (M. Méndez Baiges, ed.), Granada: Comares
Review of the book Arte Escrita, which -coordinated by Maite Méndez Baiges- offers us a tour of the text and image in contemporary art from the point of view of gender
A Multiple Radar Approach for Automatic Target Recognition of Aircraft using Inverse Synthetic Aperture Radar
Along with the improvement of radar technologies, Automatic Target
Recognition (ATR) using Synthetic Aperture Radar (SAR) and Inverse SAR (ISAR)
has come to be an active research area. SAR/ISAR are radar techniques to
generate a two-dimensional high-resolution image of a target. Unlike other
similar experiments using Convolutional Neural Networks (CNN) to solve this
problem, we utilize an unusual approach that leads to better performance and
faster training times. Our CNN uses complex values generated by a simulation to
train the network; additionally, we utilize a multi-radar approach to increase
the accuracy of the training and testing processes, thus resulting in higher
accuracies than the other papers working on SAR/ISAR ATR. We generated our
dataset with 7 different aircraft models with a radar simulator we developed
called RadarPixel; it is a Windows GUI program implemented using Matlab and
Java programming, the simulator is capable of accurately replicating a real
SAR/ISAR configurations. Our objective is to utilize our multi-radar technique
and determine the optimal number of radars needed to detect and classify
targets.Comment: 8 pages, 9 figures, International Conference for Data Intelligence
and Security (ICDIS
Jesús Aguirre : las múltiples facetas de un intelectual
The aim of this article is to highlight the little-known, but influential role Jesús Aguirre played in Spanish intellectual and cultural life throughout his career. His role as a communicator serves as a link, giving a sense of continuity through his different occupations as a priest, translator, editor, aristocrat, socialite and writer. Some of his most notable contributions include his role in fostering the Marxist-Christian dialogue, as well as the introduction and promotion in Spain of the thought of the Frankfurt School, which in turn had an impact on the intellectual coordinates which marked the Spanish Transition to democracy
Bias and Sensitivity of Nonlinear Models for Seismic Response of Ordinary Standard Bridges
The implementation of nonlinear structural analysis under large deformation demands has enabled more realistic response prediction in comparison with the classical linear approaches. However, the sensitivity to modeling assumptions, element and material formulations, implementations, and parameter selection may lead to unreliable results. While previous works have led to a better understanding of how to best model nonlinear static responses of bridge components and systems, the introduction of dynamic loads and the corresponding material hysteresis presents an additional source of variability in the nonlinear responses. The current research involves the analysis of two ordinary standard bridges in California under seismic load in SAP2000 and OpenSees after a calibration phase to standardize the material, section, and element-level nonlinear static responses. The bridges were defined using simplified steel and concrete constitutive models in concentrated plasticity elements, with common unloading-reloading rules, damping, and mass. Analyses showed that minor differences in the material constitutive models did not impact agreement of drift, base shear, and curvature time histories. The column hinge and abutment nonlinear characterization clearly dominated the dynamic response variability of the bridge models. The bias analysis of the nonlinear model concluded that both software agreed after improving the hinge length and the inclusion of gaps in the abutments. The same SAP2000 models were used to analyze the sensitivity of the most representative nonlinear parameters in the columns, superstructure, and abutments, as well as sensitivity to the hysteresis behavior of the concrete and the reinforcement steel. The prediction of the sensitivity was obtained applying the finite difference method, perturbing each parameter forward and backward by a coefficient of variation. The results obtained indicate that the selected bridges have a strong sensitivity in the longitudinal direction to the hysteretic assumptions and to small variations in parameters such as steel yield strength, superstructure Young\u27s modulus, and abutment strength, while the displacement response in the transversal direction seems to be insensitive
MarÃa Zambrano Alarcón (Vélez Málaga, 1904 - Madrid, 1991) [Semblanza]
This article explores MarÃa Zambrano's brief and significant task as a journal editor for Hora de España during the Spanish Civil War
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