1,720,979 research outputs found
Note sui problemi idrogeologici nella progettazione di sistemi di contenimento degli inquinanti
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Tunnelling in landslide areas connected to deep seated gravitational deformations: An example in Central Alps (northern Italy)
No full textTunnel excavation in mountainous regions often interacts with landslide phenomena. This paper deals with potential hazards arising from tunnelling in presence of a Deep-Seated Gravitational Slope Deformation (DSGSD), with specific reference to a case study located in Valtellina (northern Italy, Central Alps). In the study area a landslide has shown evidences of activation along the border of a wide DSGSD, where a tunnel has recently been excavated. The conceptual model of both the slope dynamics and the tunnel construction was first reconstructed, by integrating surface and subsurface surveys (from drillings and geophysical investigations to convergence tunnelling measurements, from topographic and inclinometric monitoring to radar interferometry and dendrogeomorphology). Data interpretation showed the presence within the slope of a thick shear zone, characterised by very weak rocks and significant water flows. When the tunnel intercepted this zone, convergences and face instabilities occurred, as well as tunnel inflow; in the meantime, slope deformation developed along the slope. These latter were probably the result of the superimposition of different effects, arising also from the long and heavy rainfall of that period. The investigation of the landslide activity based on dendrochronological analysis confirmed its correlation with rainfall, as well as the contribution of tunnelling. A similar behaviour is also confirmed by the results of stress-strain numerical simulations. Numerical results showed that groundwater rising due to long and heavy rainfall can contribute to slope instability much more than tunnelling itself. Moreover, they showed that the existence of shear and fracture zones connected to the DSGSD determines both an increase in tunnel inflow as well as in tunnel convergences. Actually, fracture and shear zones act as high permeability flow paths within the slope, draining groundwater towards the tunnel and increasing the surface settlements in a wide zone of the slope, worsening the slope stability conditions without triggering the collapse
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Proposta di classificazione sintetica e mappatura della qualità di base delle acque sotterranee.
No full textVariations on the Author
No full text“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
No full textWe 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
No full textWe 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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