1,721,135 research outputs found
Concentrated Slip and Low Rupture Velocity for the May 20, 2012, MW 5.8, Po Plain (Northern Italy) Earthquake Revealed From the Analysis of Source Time Functions
We analyse the rupture properties of the May 20, 2012, MW 5.8, Po Plain (Northern Italy) earthquake by using two different modeling procedures based on the source time functions: a forward modeling and a global inversion Bayesian method. While the forward modeling allows to retrieve general information on the source characteristics, the global inversion allows to explore a substantially larger number of possible solutions, with more parameters, providing a quantitative estimate of the misfit. We invert for the spatial slip distribution and for the rupture velocity on a planar fault model. The unknown slip is given at the nodes of the subfaults (control points) and then given at the elementary subfaults through a bilinear interpolation. The number of control points is progressively increased to move from a high‐ to low‐wavelength description of final slip on the fault plane. The optimal model parameter set is chosen according to the Akaike Information Criterion. The uncertainty on the slip distribution and rupture velocity has been estimated by a statistical analysis of the model ensemble and, in particular, through the weighted mean model and the standard deviation. We find that the most earthquake slip occurred in the regions located northeast and southwest of the hypocenter, consistent with the forward modeling. Moreover, we find a low rupture propagation velocity (0.4 compressional Mach number) similarly to what has been observed for the close 29 May, MW 5.6, and radiation efficiency suggesting that half of the strain energy was used to create new fracture
High resolution microseismicity data constraining the activity of the Altotiberina low-angle normal fault, Northern Apennines (Central Italy).
Onboard Hyperspectral Super-Resolution with Deep Pushbroom Neural Network †
Hyperspectral imagers on satellites obtain the fine spectral signatures that are essential in distinguishing one material from another but at the expense of a limited spatial resolution. Enhancing the latter is thus a desirable preprocessing step in order to further improve the detection capabilities offered by hyperspectral images for downstream tasks. At the same time, there is growing interest in deploying inference methods directly onboard satellites, which calls for lightweight image super-resolution methods that can be run on the payload in real time. In this paper, we present a novel neural network design, called Deep Pushbroom Super-Resolution (DPSR), which matches the pushbroom acquisition of hyperspectral sensors by processing an image line by line in the along-track direction with a causal memory mechanism to exploit previously acquired lines. This design greatly limits the memory requirements and computational complexity, achieving onboard real-time performance, i.e., the ability to super-resolve a line in the time that it takes to acquire the next one, on low-power hardware. Experiments show that the quality of the super-resolved images is competitive with or even surpasses that of state-of-the-art methods that are significantly more complex
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Microseismic activity on a low angle normal fault (northern Apennines, Italy). European Geosciences Union.
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