1,720,989 research outputs found
Simplified Clear-Sky radiative transfer Model (SCSM)
No full textThe code includes relevant functions for clear-sky radiative transfer calculations over ocean under low atmospheric aerosol load.
The clear-sky radiance over ocean in the visible range (here at 807 nm) depends on a narrow set of parameters and can be estimated by simplified 1D radiative transfer calculations. Knowing the extraterrestrial irradiance emitted by the sun and entering the atmosphere, the radiative transfer code describes the radiance at any location (x, y, z) and for any direction defined by zenith and azimuthal angles. In a clear-sky atmosphere with small solar and viewing zenith angles we can use 1D plane-parallel radiative transfer to estimate the radiance observable at the top of atmosphere or from a sensor in space.
The clear-sky radiance reaching a sensor in space is a combination of three main components: (1) the direct sun ray reflected at the ocean surface and (2) the hemispheric diffuse radiance reflected at the surface towards the sensor. On the way from TOA to the surface and back to the sensor the radiation is attenuation following Lambert-Beer and depending on the atmospheric optical thickness and the cosine of the sensor or view zenith angle. In addition, there is component (3), the diffuse light from single-scattering events happening within the atmosphere.
Several modular python functions describe the components and simplified radiative transfer calculations needed to derive the direct and diffuse components of solar radiation reaching the ground, as well as the amount reflected by an ocean surface. How the light is reflected at the surface into the view direction of a sensor is characterized by the bi-directional reflection function which depends on the surface wind speed and the generated ocean wave slope distribution following the Cox and Munk parameterization. For the diffuse downwelling radiance we make use of a look-up table included in this package (LUT_diffuse_radiance.nc). The diffuse upwelling radiance is approximated by integrating over single-scattering events including the Henyey Greenstein approximation for the scattering phase function.
A complete description of the simplified clear-sky model is provided within a paper manuscript intended for submission to Atmospheric Chemistry and Physics (ACP) under Mieslinger et al., 2021
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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