1,720,973 research outputs found
GIS ANALYSIS OF THE SEISMIC DAMAGE ON HISTORICAL MASONRY SPIRES
Full text linkThe Emilia 2012 earthquake highlighted the high vulnerability of historical masonry spires, at the top of bell towers. Indeed almost half of the spires, in the area hit by the seismic event, show the loss of the top. The observed collapse mechanism consists in sliding of the spire top and in the resulting overturning. Once the emergency phase has passed, it is now a duty to learn from this traumatic experience and to provide new tools for the prevention of the destructive effects of future earthquakes. In this perspective, a geodatabase was designed, using the ArcGIS Pro software, for monitoring the vulnerabilities of the surveyed spires. Indeed, as we learn from the study of the effects of past earthquakes, seismic damages are recurrent for each building typology and therefore they can be predictable and avoidable. For example, by statistically elaborating the data of the designed database, a correlation arose between the levels of damage of the spires and their type of masonry arrangement. Indeed four different masonry typologies have been distinguished. The work then focuses on three damaged spires of churches belfries, proposing three consolidation hypotheses to prevent the future loss of the rebuilt top part of the spire. The structural analyses, performed with Abaqus CAE and detailed in a different work, showed that the same intervention produces different results on the different case studies: a demonstration that there is not an “absolute” best solution, but an intervention suitable for each case
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
GIS Methodologies for the Management of Seismic Risk and the Damage Prevention on Masonry-Built Heritage
No full textThe Geographic Information System (GIS) is increasingly used in the scientific field for the management and conservation of built heritage. The present paper proposes a GIS methodology for the collection and analysis of the data related to the seismic risk and for the management of damage prevention interventions on masonry architectural assets, based on the empirical approach. Indeed, starting from the observation of real damage, that occurred after the recent Italian earthquakes, it was possible to collect a large amount of data, which has been organized and queried using the GIS tool. This methodology was tested on two different architectural typologies, designing two different databases: protruding elements and fortified architectures. This proactive tool allowed both the correlation between constructive features and damage mechanisms, through statistical analyses, and the comparison of the damage levels with the seismic action of the site, through the introduction in the GIS of the shake-maps, to identify the empirical fragility curves, which represent the expected damage, depending on the seismic action. Then, these functions were applied to an area without earthquake damage, using the seismic actions provided by the hazard map. This methodology allowed the identification of the assets most at risk in case of future seismic events, on a large scale. Knowing the vulnerabilities of the heritage means being able to act preventively, with planned conservation strategies, optimizing the management of economic resources, and minimizing invasive interventions
Masonry spires: 3D models to understand their seismic vulnerability
No full textThe May 2012 Emilia earthquake has highlighted the important vulnerability of masonry spires at the top of bell towers of churches. Indeed, almost half of those in the epicentral area have shown a typical damage mechanism consisting in the shear sliding and overturning of the top of the spire. Given the recurrence of this phenomenon, the present paper tries to provide a contribution to the comprehension of the seismic behaviour of the spires through the numerical analysis of three case studies. In particular, the work analyses the spires of the churches of San Nicola di Bari in Cortile, near Carpi (MO); Sant'Egidio in Cavezzo (MO), and Sant'Agostino in Sant'Agostino (FE). The numerical models of these masonry structures were made using Abaqus Finite Element software. After the creation of the three-dimensional geometric models, a first nonlinear static analysis of the entire bell tower was performed adopting for masonry the Abaqus “concrete damage plasticity model”. Once the stability of the bell tower was verified for dead loads, the non-linear time-step dynamic analysis was faced. This required the definition of the seismic input at the base of the tower, through the accelerograms recorded by the closest stations. The nonlinear dynamic analysis of the global model of the bell tower provided the floor response spectra at the base and at the top of the spire. Indeed the comparison between spectra at the ground and at the top highlights the filter effect of the stem of the bell tower with a significant increase in accelerations at the top. This effect may explain the widespread damage observed at the top of the spires. Eventually, three different non-invasive intervention techniques were proposed in compliance with the principles of restoration and were modelled to compare their behaviour
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
- …
