1,720,960 research outputs found
Surveying flash flood response: gauging the ungauged extremes
No full textThe monitoring of flash flood events gives us the unique opportunity to observe how catchments respond when most of the surface and subsurface hydrologic flow paths are active. These events often reveal aspects of hydrological behaviour that either were unexpected on the basis of weaker responses or highlight anticipated but previously unobserved behaviour (Archer et al., 2007; Delrieu et al., 2005). Characterizing the response of a catchment during flash flood events, thus, may provide new and valuable insight into the rate-limiting processes for extreme flood response and their dependency on catchment properties and flood severity.
Flash flood events, however, are difficult to monitor because they develop at space and time scales that conventional measurement networks of rain and river discharges are not able to sample effectively (Creutin and Borga, 2003). As these events are locally rare, they are also difficult to capture during classical field-based experimentation, designed to last a few months over a given region, or on experimental catchments with drainage areas of a few km2. This explains why the investigation of flash flood events is by necessity event-based and opportunistic as opposed to driven by observations from carefully designed field campaigns. Post-event surveys play therefore a critical role in gathering essential observations concerning flash floods.
Traditionally, indirect peak discharge estimates and collection of rainfall maxima have been used to document these events, as well as to provide an answer to the questions that are invariably asked after a major flood: Why did such a major flood occur? and How frequently might such a flood be expected to occur? Collectively, these studies contributed to the establishment of regional peak discharges envelope curves and to the development of more understanding of regional behaviour of extreme floods. However, focus on peak discharges and point rainfall maxima alone provides limited insight into the hydrological controls of flash flood response.
Flash flood monitoring requires rainfall estimates at small spatial scales (1 km or finer) and short time scales (15-30 minutes, and even less in urban areas). These requirements are generally met by weather radar networks. This is shown schematically in Figure 1, which reports typical monitoring scales of weather radar systems and raingauge networks together with the time and space scales of a number of flash flood generating storms observed in Europe in the last 15 years (Borga, 2007). Rapidly increasing availability of good quality weather radar observations is greatly expanding our ability to measure and monitor the rainfall distribution at the space and time scales which characterise the flash flood events (Borga et al., 2007). These technical advances have the potential to enhance the information content of post-event surveys. Realising this potential calls for the development of a methodology for flash flood response survey which goes beyond the collection of indirect peak discharge estimates by focusing on three concepts, which are revised in this short commentary
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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