1,720,955 research outputs found
Assessing the stability of underground caves through iSUMM (innovative, straightforward, user-friendly, mechanically-based method)
No full textA huge number of sinkhole events has been recorded in different Italian urban areas, with an occurrence frequency largely increasing in the last decades, sometimes even causing loss of human lives. The main reason for such catastrophic events is the presence of man-made underground cavities, excavated within soft rocks, several decades ago and then abandoned, at shallow depths. Here, the possibility of interaction with overlying buildings and infrastructures and the corresponding sinkhole hazard is relatively high. In such contexts, the low mechanical properties of the soft rock formations where the cavities have been excavated, like those formed of calcarenites, which outcrop in large areas of Southern Italy, and their high susceptibility to weathering processes, represent one of the most important predisposing factors for instability. Therefore, assessing the stability of underground cavities is crucial for land management and planning purposes. The mechanically-based stability charts developed by Perrotti et al. (Int J Geomech 18(7):04018071, 2018) have proved to be a valid tool for preliminary stability assessment and, although allow to identify an eventual proneness of the cave to instability, they do not provide quantitative assessment about the safety margin itself. In that regard, this study intends to present the most recent outcomes obtained in the development of the methodology and is aimed at promoting an enhanced way for their application, so that the charts can become an operative tool for preliminary sinkhole hazard assessment in similar regions in the world
Developing mechanically-based charts to address the assessment of underground cave stability
No full textNatural or anthropogenic sinkholes threaten diffuse areas of the italian territory. A specific research project aimed at defining an overall methodology for susceptibility analysis and risk mitigation of underground cave sinkholes, from cave identification to modelling failure mechanisms and defining mitigation interventions, has been recently developed. Based on two levels at different scale of analysis, i.e. urban area and single cavity scale, the methodology at the first level is aimed at defining quantitative procedures to assess in a preliminary way the stability of underground caves at the urban area scale. As a matter of fact, when dealing with a large number of cavities, single-cavity scale investigations can be time- and cost-consuming, resulting in huge economical investments. Therefore, a preliminary approach to detect those caves that are characterized by relatively high failure susceptibility level is necessary to make choices for investing more sophisticated analyses. In particular, the project has furtherly developed a methodology already proposed by Perrotti et al. (2018, 2019) aimed at assessing the stability conditions of underground caves by using charts based on the results of parametric finite element analyses. The use of such stability charts is straightforward since they are based only on simple information regarding the cave geometry and the geo-mechanical parameters. An advanced version of the charts has been proposed in the aforementioned project, which
includes also the quantitative assessment of a safety factor range. The enhanced version of the stability charts has been also validated against field data.The methodology is not intended to replace proper site-specific stability analyses and models implementing the actual cave geometry and the rock mass stress-strain state and should be considered only for speditive preliminary stability assessment
Le cavità sotterranee del territorio pugliese, un patrimonio culturale-architettonico da valorizzare: il progetto di ricerca PRIORITA’ per la caratterizzazione, la valutazione della stabilità, la messa in sicurezza e la fruibilità.
No full textLe cavità sotterranee (naturali e/o artificiali), ampiamente diffuse in Puglia, rappresentano un importante patrimonio storico-culturale-architettonico, spesso
non adeguatamente valorizzato, anche in ragione della pericolosità intrinseca legata alla possibilità di sprofondamenti. Tali fenomeni di instabilità (sinkholes)
rappresentano un rischio sempre più diffuso, a causa delle crescenti interazioni tra cavità ed ambiente antropizzato. Il lavoro discute i risultati del progetto di ricerca PRIORITA’ (PRogetto IntegratO di mitigazione del RIschio da sprofondamento di caviTA’) finalizzato ad offrire un contributo innovativo per la mitigazione del rischio da sinkholes. Esso è stato articolato con attività che spaziano dalla catalogazione delle cavità, alla definizione di procedure sulla stabilità, alla messa a punto di tecnologie di messa in sicurezza e, infine, alla valorizzazione. Una prima fase di studio è stata condotta alla scala del centro urbano, e una seconda su singole cavità, per individuare procedure metodologiche innovative per il rilievo, la valutazione della stabilità, il monitoraggio in sito, la sperimentazione di tecniche di messa in sicurezza efficaci ed a basso impatto, e la valutazione storico-culturale-economica per una adeguata valorizzazione. I metodi sono stati sperimentati in due siti di studio: Canosa di Puglia, caratterizzata da numerose cave sotterranee di estrazione della calcarenite, e Massafra, con varie tipologie di cavità della civiltà rupestre
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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