1,721,001 research outputs found
Optimisation of starting conditions in track cycling
No full textPurpose
Several factors may influence cycling performance and effort intensity during cycling competitions. The present study aimed to investigate the conditions that may influence the initial acceleration during the first 5 m of a cycling competition, particularly riding position, starting angle of the crank and hand position on handlebars. To this aim, eight male cyclists amateur were tested in laboratory and on track.
Methods
Surface electromyography was also used to verify the influence of upper body on muscle activity. Moreover, to verify the results, 59 professional cyclists were observed on the track using the same set-up.
Results
Standing position increased by 10 % the initial speed and acceleration compared to seated position. A starting crank angle of 71° and the position of the hands on the upper bar of the handlebar also improved the acceleration. The effects of these parameters were additive and, therefore, the acceleration with standing position and initial crank angle of 71° was about 35 % greater than that with seated position with an initial crank angle of 47°.
Conclusions
These effects were especially important when analysing the results of competitive athletes, which also showed better initial acceleration under spontaneously adopted optimal initial conditions.
2014 Springer-Verlag Italia
The contribution of vertical explosive strength to sprint performance in children
No full textPurpose This study aimed to investigate the relationship between the explosive strength ratio, which is the quotient between maximum height achieved after counter-movement jump with arm and maximum height achieved after standing start jump, and the 30-m sprint performance. Method Eighty-four children performed a series of 30-m sprints, Counter-movement jump with arm (arm-CMJ) and Starting Long Jump (SLJ) (with both legs) in randomized block order during the same testing session. Pearson's product moment correlation coefficients (r) were used to determine the relationship between the explosive strength ratio and sprint performance. The coefficients of determination (R2) were used to examine the amount of explained variance between tests. Stepwise multiple regression analysis was used to estimate the best predictor model of sprint performance. Results The correlation coefficient between explosive strength Ratio: arm-CMJ/SLJ, 10, and 30-m sprint time was moderate (r = 0.40 and 0.48 respectively). However, correlation with flying time 10 < 30-m sprint time (r = 0.52) was large. The Ratio: arm-CMJ/SLJ was the best single predictor factor (p < 0.001) of the flying time 10 < 30-m sprint time, and explained 27 % of the variance. Conclusion For improving sprint performance as well as maximal speed and flying time, coaches could ensure the explosive strength ratio as an index to calibrate sprint development program and also for enhancing sport speed in children. They will be able to use this finding to better test and monitor children's athletes requiring different skills and to evaluate the effects of speed training in children. ?????? 2014 Springer-Verlag Italia
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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