1,721,263 research outputs found
Statistical behaviour of directional bound long waves
No full textThe statistical behaviour of bound long waves is deduced from numerical simulations carried out starting from local spectra derived from deep-water directional specta. The investigation refers both to the time and space domain, in the directions of wave fronts, that is alongshore if an head on attach towards a uniform beach is considered. The values of the heights, periods and front lengths of the bound long waves are obtained and compared with those of the nonlinear waves associated with the complete second order local spetra. The influence of the directional energy spreading is examined, wich seems to affect the periods and lenghts of the wave fronts more than the heights of the bound long waves. The numerical results of the analysis carried out in a coastal region and illustrated here with reference to field cases from Bowers (1992) show the following: the energy density of the bound long waves increases as the depth decreases, being, in any case, about 10% of the local energy density associated with the complete second order spectra; the spectral mean periods referred to the bound long waves exhibit an increasing trend in decreasing depth; the characteristic lengths of the wave fronts assume quite the same values whatever the depth. The last result suggests that beach configurations induced by bound long waves are affected by the features exhibited by the bound long waves approaching the coastal region, which depend on the deep-water wave climate rather than on the modification experienced during the shoreward propagation
Influence of the distribution of the random wave heights on the longshore current velocity
No full textA cross shore distribution of the longshore current velocity is given in an analytical form starting from a spectral wave propagation model and a wave-induced model based on a proper probability distribution functio
The Dynamic Pressure on Smooth anf Rough Sloped Walls under Regular and Irregular Waves
No full textExperimental investigation carried out to examine the dynamic pressures acting on smooth and artificially roughed inclined walls under regulare and irregulare wave
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
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