1,720,973 research outputs found
Enhancing Impact Testing of Protective Polymer-based Foams According to EN 913 for Application in Sports Area
No full textThis paper shows preliminary results of a research aimed to improve passive safety of gymnastic equipments. To assess the impact attenuation performances of protective devices, mainly realized with polymer-based foams, impact testing standards are applied. Due to lack of criticism about test procedures and analysis of experimental results, the choice of the most safe device is not trivial. The first part of the paper shows the main impact testing procedures provided by international standards and defined for gymnastic equipments and playground area. In accordance to these standards the main impact attenuation performances for passive safety assessment are defined. The second part of the paper shows first experimental results obtained using new testing apparatus developed at the Sports Equipment and Technology Lab of Chemnitz University of Technology. Impact attenuation performances of two protective devices realised with polymer-based foams are analysed. The parameter of theoretical drop height is introduced to compare experimental results collected in our laboratory with others previously collected in an accredited laboratory. The comparison of test standards reveals a lack of specification in EN 913. Finally, new experimental sessions are planned to optimize material and architecture of polymer based foams used as protective device in order to easily assess passive safety improvement for gymnastic equipment
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
Toward a New Approach for Passive Safety Assessment of Gymnastic Equipment
No full textPurpose: Aim of the paper is to propose a new approach for the assessment of passive safety of gymnastic
equipment that allows technicians to optimize the choice of protection devices.
Design/methodology/approach: According to different standard procedures, EN 913 and EN 1177 with an
additional control on the acceleration parameter, experimental tests on polymer foam materials were performed
using cylindrical and hemispherical missiles connected to a flexible impact testing apparatus realized at
Chemnitz University of Technology.
Findings: Impact tests carried out using cylindrical and hemispherical missiles have shown, for the same impact
energy, different acceleration peak values, always greater for hemispherical missile than cylindrical one. So
considering EN 913 procedure, the severity of head impacts, in term of acceleration peak can be underestimated
when a cylindrical missile is used. For this reason to correctly assess the head injuries is necessary to take into
account in addition to the acceleration peak value, also HIC parameter.
Research limitations/implications: The research described in the paper was carried out taking into account
only the human head impacts (the most severe injuries) and not other parts of the human body.
Practical implications: The new approach proposed in the paper can be useful for the choice of the protective devices
to improve the passive safety of gymnastic equipment. It represents a starting point to define new standards.
Originality/value: On the base of experimental tests, the authors show that the safety threshold of peak
acceleration defined in the EN913 standard is poor. For this reason it is necessary to modify the current
standards, in order to guarantee an adequate passive safety and to allow the technicians to optimize the choice
of protection devices on the base of impact absorption properties, that are evaluated using all together the
parameters: acceleration peak, drop height and Head Injury Criterion (HIC)
Improving Passive Safety of Sports Equipment through Experimental Testing of New Protection Devices
No full textkoamabayili/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
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