1,721,026 research outputs found
Towards more efficient tractors: Assessing and refining traction test procedures for agricultural tractors
No full textA reliable testing procedure is needed to benchmark different vehicle and tyre parameters. Several testing procedures within two main families – transient and steady states – were adopted to evaluate drawbar performance of tractors. The two procedural families were not hitherto compared using a full vehicle. This article aims to fill this gap. The transient and steady-state procedures were tested using a tractor rated of 230 kW sets in different configurations and equipped with sensors for evaluating the tractive parameters. In the transient procedure, the drawbar load was continuously increased to maintain a fixed ground speed. In the steady-state procedure, the drawbar load was gradually increased by reducing the ground speed. The maximum drawbar force generated by the tractor differed little between procedures, but a difference was observed in power delivery efficiency, mostly for the transmission’s influence during transient conditions leading to variable transmission efficiency. The results of the steady-state procedure for different vehicle configurations were more consistent with findings in the literature than those of the transient procedure. The steady-state procedure is better than the other but it requires more land and therefore it is less convenient when drawbar performances must be quickly evaluated for many vehicle and soil configurations
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
On the Traction Tests: How They Affect the Performances of Tractor Tyre Combination
No full textIn the last decades improving efficiency became the predominant theme of tractors and tyre manufacturers. Performed traction tests on the field are the most helpful instrument for evaluating vehicle performances under different load conditions that can rapidly replicate real tractor configuration and usage. This work performed two traction test procedures with a New Holland tractor with continuously variable transmission equipped with Michelin very-high flexion tyres and wheel force transducers. This tractor was connected to another used as a braking unit and tested with two traction test procedures denoted as transient and steady-state procedures. In the former, the braking unit was driven at a fixed velocity and the pulling tractor increased the wheel velocity, progressively increasing the drawbar force. Instead, in the second, the pulling tractor was driven at a fixed velocity and the braking unit reduced its velocity at different levels thus applying a discretely increasing drawbar force. The collected data were analysed to evaluate parameters related to traction capability and efficiencies, such as vehicle traction ratio, traction efficiency and power delivery efficiency. Procedures were compared in terms of reproducibility, variability, and repeatability. Both test methods have pros and cons, but the steady-state procedure provided better accuracy in the results, an easier way to impose and control different test parameters, and the best test-to-test repeatability. The results of this work help understand how data collected by traction tests performed with the latest generation tractors could be affected by the testing procedures
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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