1,720,966 research outputs found
Surface displacement of two active rock glaciers in the Adamello-Presanella Group (Central Italian Alps): a 7-year monitoring series
No full textMountain permafrost acts as an aquiclude during an infiltration experiment monitored with ERT time-lapse measurements
No full textOsservazioni e studi sul permafrost in Trentino: il progetto PermaNET
No full textNell’articolo sono presentate le attività di ricerca svolte sul permafrost in Trentino e i principali risultati del progetto PermaNET (Permafrost Long-term Monitoring Network). Sono stati realizzati un catasto dei rock glacier e una carta dell’indice di diffusione del permafrost derivata da un nuovo modello statistico della sua localizzazione. Inoltre, sono state avviate numerose attività di monitoraggio: tra queste, sono in corso misure di temperatura della superficie del suolo e sono proseguite misure topografiche per quantificare lo spostamento di due rock glacier attivi. Sono stati inoltre attrezzati due siti per la misura della temperatura del sottosuolo e dei parametri climatici esterni, allo scopo di valutare la condizione termica del permafrost in funzione dei cambiamenti climatici. La collaborazione al progetto ha consentito di migliorare considerevolmente la conoscenza di questo importante aspetto dell’ambiente alpino del Trentino
Case studies in the European Alps – Maroccaro rock glacier, Val di Genova, Italian Alps
No full textIn 2001 we started a topographic study on an active rock glacier (named Maroccaro rock glacier, acronym MaRG, coordinates: 46° 13’ 06” N, 10° 34’ 34” E) located in the Adamello-Presanella massif (Central Italian Alps). Since 2004, also the near-surface ground temperature was measured using a miniature data logger. Our data show that in eight years (2001-2009) MaRG has moved downslope with average velocities ranging from 0.02 to 0.21 m/year. The velocity reaches a maximum in the middle and the lower part of the rock glacier, and decreases towards the upper sector, where the surveyed boulders are almost stationary. A considerable different velocity from year to year has been observed, but no clear trends seem to emerge from the mean annual displacement rate. On the rock glacier the evolution of the ground temperature since 2004 is directly associated with the air temperature and the snow conditions, in terms of thickness and duration of the snowpack. The ground has warmed significantly both in 2007, after a very mild and little snowy winter, and in 2009, after a cold but exceptionally snowy winter. The displacement rate of MaRG seems to rapidly react to the ground temperature variations, apparently without any time delay. The exceptionally snowy winter 2008/09 seems to have played a significant role on the displacement rate, causing a ground temperature increase and, probably, an increase in velocity, which reached its maximum in that year
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
Case studies in the European Alps – Amola rock glacier, Val d'Amola, Italian Alps
No full textTopographic measurements are in progress since 2001 on a glacier-derived, active rock glacier (named Amola rock glacier, acronym AmRG, coordinates: 46° 12’ 09” N, 10° 42’ 46” E) located in the Adamello-Presanella group, Central Italian Alps. In addition, data on the ground temperature measured few centimetres below the surface are available since 2004. The displacement data show that some areas of the rock glacier currently (2001-2009) move with velocities ranging from 10 to 20 cm/year, while other sectors can be defined as “dynamically inactive”. The average velocity is significantly variable from year to year, ranging from a minimum of 0.06 m/year (2007-2008) to a maximum of 0.13 m/year (2006-2007), and a slowing trend has been recorded in the last two years. In 2006-2007 a higher rate of displacement seems to be related to a rise in the mean air temperature that probably caused a corresponding rise in the ground temperature. However, in the last year of measurements (2008-2009), an increase in the ground temperature caused by the large amount of snow of the preceding winter, did not result in a corresponding increase of the displacement rate. The dynamic behaviour of this rock glacier reacts very fast to the external forcing, and its response seems to be modulated by the amount and evolution of the snow during winter, due to its effect on the ground temperature. Thus, not only the temperature but also the projected changes in the amount and distribution of precipitation, especially as snow, should be taken into account in assessing the response of this landform to future climate change
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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