1,721,023 research outputs found
Evaluating sources of uncertainty and variability in rock glacier inventories
No full textThis paper aims to evaluate sources of uncertainty and variability associated with rock glacier inventories compiled from remotely sensed imagery. To this end, we ran three mapping exercises in Kaiserbergtal, Austria. To evaluate interactions between mapping style and imagery resolution, we asked six operators to map and assess the degree of activity of all rock glaciers they could identify – first on Google EarthTM (GE) imagery and then on a set of higher‐resolution orthophotos and LiDAR‐derived images (LO) (Exercise 1). To compare the mapping attributes on a common set of rock glaciers, we asked 14 operators to delineate the outline of four designated rock glaciers (Exercise 2) and to classify the activity of 15 designated rock glaciers (Exercise 3) on LO. Results show strikingly high inter‐operator variability. Specifically, we show that the number of mapped rock glaciers on GE can vary up to a factor of 3, and that using LO lowers this figure to a factor of 2, while producing an increase in the number of mapped landforms, which become systematically smaller (Exercise 1). Examination of polygon outlines identifies highest inter‐operator variability at the transition with the rooting zone and, in polymorphic rock glaciers, on adjacent creeping lobes. Variability is higher for relict landforms (Exercise 2). Operators’ activity assessments, evaluated against an independent quantitative activity index (RGI), display reasonable agreement for active and relict landforms, whereas inactive counterparts meet least consensus and therefore are problematic (Exercise 3). We further show that this variability in mapping outcomes propagates across compound variables, and must be considered when assessing uncertainties and confidence levels of environmental evaluations that rely on rock glacier inventories, such as the lower altitudinal limit of discontinuous permafrost, or water storage potential. We call for an international effort to establish guidelines for rock glacier classification and mapping, towards more homogeneous inventories. © 2019 John Wiley & Sons, Ltd
The vulnerability of buildings affected by powder avalanches
No full textThe major problem in the estimation of avalanche risk is the evaluation of vulnerability, that is the degree of loss to a given element or set of elements at risk within the area affected by avalanches, because of the paucity of suitable data to evaluate the effects of avalanches on people and properties. Few are the studies about this component of avalanche risk, particularly concerning snow avalanche effects on "alpine-type" buildings. In the present work an empirical vulnerability relation for "alpine-type" buildings affected by powder avalanches is proposed, using the data from two catastrophic avalanches that occurred in Austria in 1988 and 1999. The curve is then compared to the theoretical estimate of the collapse load of non structural elements of the buildings affected by the Morgex avalanche, occurred in Aosta Valley (Italy) in 1999
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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