1,720,977 research outputs found
Caratteristiche di resistenza del materiale vulcanoclastico della Sciara del Fuoco (Stromboli)
No full textNella nota sono descritti i risultati di una serie di prove di laboratorio per lo studio della resistenza al taglio del materiale vulcanoclastico coinvolto negli eventi franosi che nel dicembre 2002 hanno interessato il versante della Sciara del Fuoco (Stromboli). Le prove sono state effettuate sia su materiale asciutto, rappresentativo delle condizioni del versante subaereo, sia su materiale completamente saturo, rappresentativo del pendio sommerso. In quest’ultimo caso, prove non drenate hanno messo in evidenza che si può verificare liquefazione statica anche negli orizzonti grossolani a patto che abbiano un significativo contento in fini quale quello prodotto a seguito di intense deformazioni di taglio
Preliminary analysis of instability phenomena at Vulcano Island, Italy
No full textVolcanic activity in the island of Vulcano is concentrated in the area of La Fossa cone, whose NE sector is affected by deep-seated deformations and shallow failures along bedding planes. Quantitative data from laboratory investigations, borehole core logging and in-situ surveys were used for the analysis of instability phenomena and to assess their relationship with volcanic activity. The influence of the marine erosion along the sides of the NE sector on the state of stress and deformation of the volcanic edifice was evaluated by means of 3D numerical analyses based on the geological and geomechanical investigations
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
Analisi della stabilità dei fianchi di edifici vulcanici: i casi di Stromboli e Vulcano
No full textVariations 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
Geomechanical Characterization of the Volcaniclastic Material Involved in the 2002 Landslides at Stromboli
No full textDuring the 2002 eruption, the NW flank of Stromboli volcano (Southern Italy) experienced large landslides that produced tsunami waves with a maximum runup of 10 m in height. This paper focuses on the geomechanical behavior of the loose volcaniclastic layers, the weakest component of the deposit forming the volcano flank. Tests on the coarse-grained volcaniclastic soil and on the rock material forming the grains were conducted in dry conditions, a feature of the subaerial slope. The rock material, in spite of its high porosity, exhibits relatively high stiffness and strength due to the remarkable continuity of the solid skeleton. Accordingly, the volcaniclastic soil is characterized by high shear strength. During shear tests, however, significant grain crushing occurs, which partly explains the nonlinear shear strength envelope and the strain softening associated with contractive behavior. Grain crushing was also found to affect compressibility and its time dependency, investigated under oedometric conditions
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