1,720,965 research outputs found
A large-scale prioritisation to strengthen the resilience of communities in Italian territorial contexts
No full textIn the aftermath of the 2009 L’Aquila earthquake, the Italian government issued significant measures
to stimulate seismic prevention in its territories. To this end, billions of euros were distributed to the
twenty Italian Regions in proportion to their seismic risk and according to the requests of public
administrators and private taxpayers. However, the distribution of resources among the Regions took
place without considering important aspects of resilience such as the emergency management and
recovery, as well as the integration and social cohesion of populations. This article proposes a framework
to identify a large-scale prioritisation of the Italian Territorial Contexts (TCs) recently defined for
civil protection purposes in order to allocate economic resources among Regions in accordance with
the resilience deficiencies of their communities. The proposal is based on known methods of multi-criteria
analysis that are commonly used in the engineering field, and as a first application, it has been
applied to all TCs of five Regions of southern Italy. The results of this study may be useful for policy
makers to develop a national resilience policy
Influence of local site effects on seismic risk maps and ranking of Italian municipalities
No full textThe latest studies concerning seismic risk assessment in Italy were developed without considering the site geo-lithological effects, thus limiting the assessment to rock soil type. In this study, for the evaluation of site amplification effects, we used the results of recent works based on the Italian seismic microzonation data. As this first study is performed for the entire Italian territory at the municipality scale, the site amplification factors (AFs) have been assigned to the chief town of each of the 7715 Italian municipalities, assuming that the building stock is concentrated in that small area. The AFs have been compared with those foreseen by the Italian building code (NTC2018). The PGA amplification with the new AFs ranges from 1 to 2.2 bringing to an average increase of 75% in the hazard, compared to 27% if using the NTC2018 amplification. The seismic risk has been evaluated using the probabilistic hazard assessment adopted in the NTC2018 and recent vulnerability/exposure models developed for Italy. The residential building stock was subdivided into 5 vulnerability classes (3 for masonry and 2 for concrete) derived from the national census data and further refined using the construction age and building height. The results show that, for a rock site condition, the loss estimates are comparable with those of previous works in terms of casualties, homeless, and economic damage. The introduction of the site effects brings to a significant increase in the expected losses resulting higher than the historical data retrieved from a careful analysis of the major Italian earthquakes. This suggests the importance of developing new fragility curves based on updated AFs. To support the implementation of risk reduction programs, a seismic risk index is introduced, allowing a municipality ranking by risk, a cost estimation of the seismic retrofitting in the highest risk municipalities, and an assessment of the consequent risk reduction
Ground motion prediction maps using seismic-microzonation data and machine learning
No full textPast seismic events worldwide demonstrated that damage and death toll depend on both the strong ground motion (i.e., source effects) and the local site effects. The variability of earthquake ground motion distribution is caused by the local stratigraphic and/or topographic setting and buried morphologies (e.g., irregular sub-interface between soft and stiff soils) that can give rise to amplification and resonances with respect to the ground motion expected at the reference site. Therefore, local site conditions can affect an area with damage related to the full collapse or loss in functionality of facilities, roads, pipelines, and other lifelines. To this concern, the near-real-time prediction of ground motion variation over large areas is a crucial issue to support the rescue and operational interventions. A machine learning approach was adopted to produce ground motion prediction maps considering both stratigraphic and morphological conditions. A set of about 16ĝ€ ̄000 accelerometric data points and about 46ĝ€ ̄000 geological and geophysical data points was retrieved from Italian and European databases. The intensity measures of interest were estimated based on nine input proxies. The adopted machine learning regression model (i.e., Gaussian process regression) allows for improving both the precision and the accuracy in the estimation of the intensity measures with respect to the available near-real-time prediction methods (i.e., ground motion prediction equation and ShakeMaps). In addition, maps with a 50ĝ€ ̄mĝ€ ̄×ĝ€ ̄50ĝ€ ̄m resolution were generated, providing a ground motion variability in agreement with the results of advanced numerical simulations based on detailed subsoil models
Seismically induced rockfall hazard from a physically based model and ground motion scenarios in Italy
No full textThe majority of landslide susceptibility and hazard zonations are implemented with statistical methods, especially on large scales: mostly because the data needed for physical simulations are only available in small areas. Physically–based simulations for slope stability are conceptually different from widely used statistical approaches. Both methods have specific advantages, depending on available data, their type and resolution, and the aim of the study. Here, we perform a hazard zonation based on the physical model STONE for the simulation of rockfalls, at 10 m resolution consistently all over Italy, and aggregating results at the slope unit level. The novelties, here, are: (i) the introduction of a seismic trigger for rockfalls, which adds a temporal component to an intrinsically static model and allows to obtain an estimate of seismically induced rockfall hazard, (ii) high–resolution application of the model at national scale, and (iii) implementation of the results in a WebGIS. Peak ground acceleration maps with different return times including seismic amplification represent the earthquake trigger. A data–driven map of possible rockfall sources all over Italy, mapped by experts in sample representative locations, allowed statistical generalization to unsurveyed areas, at national scale. Eventually, application of a simple linear transformation, to map values of peak ground acceleration into activation probability of sources, links “static” rockfall simulations with “dynamic”, time–dependent triggering. Results are maps of rockfall susceptibility with different return times, i.e., a step forward to the full assessment of rockfall hazard. Maps of hazard values and corresponding uncertainties, aggregated at slope unit level and categorized, are readily available for download, and for visualization in the new WebGIS. The new model for seismic triggering of rockfalls can be applied at the local and regional scale, calibrated with specific earthquake events instead of the return time scenarios considered here. On the temporal scale, this approach in principle is suited for application in near–real time
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
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
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