1,720,961 research outputs found
Reconstruction of lithotechnical terrain units for the assessment of shallow landslides hazard in Oltrepò Pavese (northern Italy)
No full textThe prediction of the areas prone to rainfall-induced shallow landslides needs of terrain units which represent
the basis for the susceptibility and the hazard zonation of the territory. Terrain units correspond generally to
sub-sections of catchments, distinguishes each other by slope angle, altitude and hydrological parameters.
Instead, the proneness of a hillslope towards shallow landsliding is strictly related also to the lithotechnical
features of the superficial soils, which are affected by these slope instabilities. Thus, the distinction of the
terrain units across a catchment should consider also these soil properties. This work has the objective to
develop and apply a methodology for the definition of the main litho-technical terrain units across a particular
area, aiming to represent an input predictor for the assessment of shallow landslides susceptibility and hazard.
The methodology was tested in the Oltrepò Pavese area (Lombardy region, northern Italy), that corresponds to
the northern termination of the Italian Apennines and is characterized by a significant predisposition towards
shallow failures events as a consequence of severe rainfalls. The following parameters are measured as basic
input for defining the terrain units: 1) soil lithotechnical profile, determined through the field evaluation of soil
density, porosity, carbonate content, resistance to the penetration; 2) grain size distibution and Atterberg limits
of the levels identified in a soil profile; 3) thickness of the soil profile. These parameters were measured in more
than 200 points, corresponding to field surveys realized in an area of about 250 km2. Soil profiles with similar
features were, then, grouped through a cluster analysis, which allowed to identify soil groups characterized
by similar lithotechnical properties. A map of distribution of these lithotechnical terrain units were obtained,
linking the features of the soil profiles with the distribution of the bedrock materials with geological features
similar to those ones of the reconstructed terrain units. The terrain unit distribution were compared with the
shallow landslides inventory map of Oltrepò Pavese area, in order to identify the most prone lithotechnical
terrain units by means of a knowledge-driven technique based on the Frequency Ratio methodology. These
results could represent the basis for a future implementation of other methodologies (deterministic or datadriven
models) for the assessment of shallow landslides susceptibility and hazard at regional scale, that could
take into account also for this terrain units. This work was made in the frame of the ANDROMEDA project,
funded by Fondazione Cariplo
L'IMPIEGO DELLA DL-CARNITINA PROTETTA NELL'ALIMENTAZIONE DELLE BOVINE DA LATTE (CONTRIBUTO SPERIMENTALE)
No full textI COMPLESSI OLIGODINAMICI CHELATI NELL'ALIMENTAZIONE DEI BROILERS (CONTRIBUTO SPERIMENTALE)
No full text
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
Development of a data-driven model for spatial and temporal shallow landslide probability of occurrence at catchment scale
No full textA combined method was developed to forecast the spatial and the temporal probability of occurrence of rainfall-induced shallow landslides over large areas. The method also allowed to estimate the dynamic change of this probability during a rainfall event. The model, developed through a data-driven approach basing on Multivariate Adaptive Regression Splines technique, was based on a joint probability between the spatial probability of occurrence (susceptibility) and the temporal one. The former was estimated on the basis of geological, geomorphological, and hydrological predictors. The latter was assessed considering short-term cumulative rainfall, antecedent rainfall, soil hydrological conditions, expressed as soil saturation degree, and bedrock geology. The predictive capability of the methodology was tested for past triggering events of shallow landslides occurred in representative catchments of Oltrepò Pavese, in northern Italian Apennines. The method provided excellently to outstanding performance for both the really unstable hillslopes (area under ROC curve until 0.92, true positives until 98.8%, true negatives higher than 80%) and the identification of the triggering time (area under ROC curve of 0.98, true positives of 96.2%, true negatives of 94.6%). The developed methodology allowed us to obtain feasible results using satellite-based rainfall products and data acquired by field rain gauges. Advantages and weak points of the method, in comparison also with traditional approaches for the forecast of shallow landslides, were also provided
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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