1,720,974 research outputs found
On the way to harness high-altitude wind power: Defining the operational asset for an airship wind generator
No full textThe utilization of high-altitude wind energy potential is a very attractive challenge. This is mainly due to the perspective of producing a large amount of electricity from a renewable source without using land, and having a very low visibility impact. The wind flow on the upper levels of the surface boundary layer is characterized by good power with low variability of wind conditions.Many innovative wind energy conversion flying devices are currently under development for this purpose. The technological solutions can be grouped in:. •land installed generators (such as kite systems);•airship flying generators that can produce electricity far from the ground and are tethered by control wires, also used for the power transmission.Flying generators could prove more problematic in maintaining flying conditions due to their heavier weight, but they have the advantage that they can be moved to different locations with less intervention on the ground.Another important characteristic that the airship wind generator has, is the possibility of changing its height of operation very quickly and simply by using control cables.In this study, the operational scenario of the possible application of an innovative airship wind generator is studied and discussed. The possibility of adjusting the height of operation was analysed, and a methodology for choosing the optimal operating level was developed and applied to real test cases. Numerical and experimental techniques used to assess the characteristics of high-altitude winds, were also considered.Remotely sensed wind data obtained from a monostatic phased-array Doppler Sonic Detection and Ranging (SODAR) system were used to validate and tune the CFD model in one of the real-test cases investigate
Improving windfarm operation practice through numerical modelling and Supervisory Control and Data Acquisition data analysis
No full textUsually, wind energy assessment on a new windfarm is conducted with maximum effort prior to the installation of the turbines by using both numerical and experimental investigations. Yet, often the windfarm performances during operation are not as good as expected. This issue can be investigated with a deep analysis of the operational conditions of the windfarm. The large amount of data collected by the SCADA (Supervisory Control and Data Acquisition) systems installed on the turbines can be very helpful. In the present study, the performances of a windfarm were analysed through the elaboration of the SCADA data from a windfarm in southern Italy; in this site, Sorgenia Green installed nine aerogenerators with a rated power of 2 MW each, on a hilly area with gentle slopes. A systematic approach is proposed to isolate the downtime because of malfunctioning and a manifold investigation is applied to the operational phase: several methods (polar efficiency plot, multidimensional graphical analysis, sectorial power curve and misalignment index, respectively) are suggested and applied for unveiling the sectors where the production output is most affected by the wake interactions. Numerical windflow modelling is performed in the wind rose sectors where underproduction is highlighted by a SCADA data analysis: finally, a SCADA database is employed for testing the goodness of the simulations
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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