1,720,985 research outputs found
Laboratory wind-waves experiments conducted at the University of Hamburg
No full textMean phase-averaged horizontal airflow velocities and power spectral densities (PSD) of high-pass filtered (with respect to frequency) wave slope measurements, obtained from laboratory experiments in University of Hamburg's (Germany) wind-wave tank. A total of 20 wind-wave conditions were examined with varying wind speeds and three different surfactants deployed on the water surface. Experiments 1–5 were performed on a slick-free surface (no surfactant), experiments 6–10 with oleyl alcohol (OLA), experiments 11–15 with palmitic acid methyl ester (PME), and experiments 16–20 with toluol (TOLG).
The horizontal airflow velocity component (aligned with the mean wind direction) was measured at various heights above the water surface, using a 2D FlowExplorer Laser Doppler Velocimetry (LDV) system (Dantec Dynamics). Raw velocity data were binned with respect to wave phase, and averaged to generate mean along-wave airflow velocity maps. Wave slope data, recorded with a laser slope gauge, were divided into short segments (chunks), each matching exactly the wave-phase interval of a specific phase bin. Chunks from multiple wave cycles that corresponded to the same phase bin were grouped together. For each bin separately, these grouped chunks were concatenated into continuous sequences. Spectral analysis was then performed on each concatenated sequence to compute the power spectral density (PSD) of the high-pass filtered (f > 10 Hz) wave slope.
This dataset includes variables with their respective coordinates: height above the waves and wave phase for the airflow velocity maps; frequency and wave phase for the PSDs.
Additionally, the wave-following coordinate and the phase-averaged surface elevation are provided. For each experimental run, friction velocity and horizontal airflow velocity extrapolated to a reference height of 10 m are provided
Experiment conditions and wave parameters of laboratory wind-waves experiments conducted at the University of Hamburg
No full textWind-wave conditions of laboratory experiments in University of Hamburg's (Germany) wind-wave tank. A total of 20 wind-wave conditions were examined with varying wind speeds and three different surfactants deployed on the water surface. Experiments 1–5 were performed on a slick-free surface (no surfactant), experiments 6–10 with oleyl alcohol (OLA), experiments 11–15 with palmitic acid methyl ester (PME), and experiments 16–20 with toluol (TOLG). For each of the 20 experiment runs, the dataset lists the friction velocity and the 10 m extrapolated wind speed, together with wave parameters derived from the wire-gauge elevation time series under linear wave theory: wavelength, peak wave frequency, wave amplitude, wave age, dimensionless roughness length, and wave steepness
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
Slicks as Indicators for Marine Processes
Full text linkMonomolecular surface films ("sea slicks") are well known to dampen small-scale waves at the water surface, thereby influencing transport processes at the air-sea interface. Because of their strong wave-damping capacity, they can often be observed, not just on synthetic aperture radar imagery, but also on imagery acquired in the visible and infrared spectral ranges. Because sea slicks tend to accumulate at the water surface along lines of, for example, current shear in fronts and eddies, they can be used as proxies for observing such marine processes from space. We demonstrate how well sea slicks are suited to indicate marine processes in the coastal zone. A slick's damping capability depends on the surfactant concentration on the sea surface and, thus, on the compression status of the slick-forming material. Furthermore, we show that slick signatures can be used to derive surface current vectors at higher spatial resolution than that of numerical models
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
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