1,721,318 research outputs found
Footprints and fetches for fluxes over forest canopies with varying structure and density
No full textA stochastic trajectory model was used to estimate scalar flux footprints in neutral stability for canopies of varying leaf area distributions and leaf area indices. An analytical second-order closure model was used to predict mean wind speed, second moments and the dissipation rate of turbulent kinetic energy within a forest canopy. The influence of source vertical profile on the flux footprint was examined. The fetch is longer for surface sources than for sources at higher levels in the canopy. In order to measure all the flux components, and thus the total flux, with a desired accuracy, sources were located at the forest floor in the footprint function estimation. The footprint functions were calculated for five observation levels above the canopy top. It was found that at low observation
heights both canopy density and canopy structure affect the fetch. The higher above the canopy top the flux is measured, the more pronounced is the effect of the canopy structure. The forest fetch for flux measurements is strongly dependent on the required accuracy: The 90% flux fetch is greater by a factor of two or more compared to the 75% fetch. The upwind distance contributing 75% of flux is as large as 45 times the difference between canopy height and the observation height above the canopy top, being even larger for low observation levels
Towards long-term standardised carbon and greenhouse gas observations for monitoring Europe ́s terrestrial ecosystems: a review
No full textResearch infrastructures play a key role in launch ing a new generation of integrated long-term, geographically dis tributed observation programmes designed to monitor climate
change, better understand its impacts on global ecosystems,
and evaluate possible mitigation and adaptation strategies. The
pan-European Integrated Carbon Observation System combines
carbon and greenhouse gas (GHG; CO2, CH4, N2O, H2O) observa tions within the atmosphere, terrestrial ecosystems and oceans.
High-precision measurements are obtained using standardised
methodologies, are centrally processed and openly available in
a traceable and verifiable fashion in combination with detailed
metadata. The Integrated Carbon Observation System ecosystem
station network aims to sample climate and land-cover vari ability across Europe. In addition to GHG flux measurements,
a large set of complementary data (including management prac tices, vegetation and soil characteristics) is collected to support
the interpretation, spatial upscaling and modelling of observed
ecosystem carbon and GHG dynamics. The applied sampling
design was developed and formulated in protocols by the scien tific community, representing a trade-off between an ideal dataset
and practical feasibility. The use of open-access, high-quality and
multi-level data products by different user communities is crucial
for the Integrated Carbon Observation System in order to achieve
its scientific potential and societal valu
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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