1,720,961 research outputs found
Ergonomic Comfort of Trekking Backpacks: Measurements of Pressure Exerted by Shoulder Straps and Hip Belt in Female Users
No full textThe pressure exerted by trekking backpacks (BPs) of different volumes and construction designs was measured in six female users using a pneumatic sensor. The aim was to investigate the effects of gender-specific design on ergonomic comfort. Although no difference was found in terms of pressure in the female BP models, a correlation was found between pressure and biometric characteristics (BMI, chest and waist circumference). The results suggest that the ergonomic comfort of BP depends on the size of the user, with slim users more likely to experience uncomfortably high pressure from shoulder straps and hip belt
Impact of Backpacks on Ergonomics: Biomechanical and Physiological Effects: A Narrative Review
Full text link(1) Background: the effects of load carriage packs on human gait biomechanics, physiology and metabolism depend on the weight carried, the design of the pack and its interaction with the user. (2) Methods: An extensive search in the PubMed database was performed to find all the relevant articles using the following keywords: backpack, rucksack, backpack ergonomy and sports backpack; 60 articles were included. (3) Results and significance: Double pack (DP) and T-pack (TP) designs are recommended solutions for school children, compared with backpacks (BP). For soldiers and hikers, a backpack remains the best compromise. A hip belt is recommended for BPs as well as for the back of DPs. Shorter and stiffer shoulder straps combined with a higher and tighter load placement on the back provide the best combination in terms of balance, muscle activation and energy expenditure. It is, therefore, possible to determine guidelines for designing the optimal load carriage system, depending on the application. (4) Conclusions: based on the available evidence, DP and TP are advantageous in terms of posture. DP is better than conventional BPs in terms of balance and muscle activation, but has the disadvantage of limited visibility, thermal sensation and obstructed ventilation. In general, it is desirable not to exceed 40% of body mass (BM)
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
Trail running biomechanics: from the lab to the mountains
No full textTrail running is an increasingly popular endurance discipline. It takes placein natural environments, such as forests, mountains or deserts. Duringcompetitions, runners may run from 5 up to over 100 km. The race courseis not flat as in road races. Rather, it may present a considerable elevationgain, with possibly steep and technically challenging uphill and downhillsections. Due to these boundary conditions, the interaction between athleteand environment plays a key role. To enhance performance, athletesmay need to optimize both their pacing strategy and running technique.Pacing strategy indicates how athletes distribute their effort across a race,to cover a given distance in the shortest time possible. Uphill sectionsrequire a high fitness level, whilst downhill sections require high technicalskills. Investing more or less energy in certain sections or in a specific racestage may have different consequences on finish time.Spatiotemporal parameters concur to determine running speed. Most likely,differences in spatiotemporal parameters are elicited by a different runningtechnique. In this dissertation, technique has been investigated in termsof joint angles kinematics. Coordination and coordination variability representfurther tools to deeper understand the motion of an athlete. In biomechanics,coordination indicates how two body segments or joint anglesbehave with respect to each other, acting in synergy to produce a certainoutput. To carry out the same task, some coordination patterns maybe more efficient than others. Coordination variability indicates how thecoordination pattern differs between multiple repetitions of a given task, orbetween different individuals. Depending on the specific situation, a higheror lower coordination variability may indicate better or poorer motor control.To gain insights into pacing strategy and biomechanics in trail running, fourstudies have been performed. In the first study, we have sought to understandwhich pacing strategy results in the lowest finish time. In the secondstudy, we have sought to understand how spatiotemporal parameters andkinematics differs between faster and slower trail runners. In the thirdstudy, we have sought to understand how coordination and coordinationvariability differ between faster and slower trail runners. In the fourth study,we have sought to understand how spatiotemporal parameters and kinematicschange between initial and final race stage. Our findings may help coaches and practitioners to I) improve their strategy during competitions,II) target specific aspects of the movement so to enhance performance.submitted by Matteo Genitrini, M.Sc.Enthält Literaturverzeichnis auf Blatt 105-123Anhang enthält vier wissenschaftliche AufsätzeDissertation Paris Lodron-Universität Salzburg 202
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
Trail running biomechanics: from the lab to the mountains
No full textTrail running is an increasingly popular endurance discipline. It takes placein natural environments, such as forests, mountains or deserts. Duringcompetitions, runners may run from 5 up to over 100 km. The race courseis not flat as in road races. Rather, it may present a considerable elevationgain, with possibly steep and technically challenging uphill and downhillsections. Due to these boundary conditions, the interaction between athleteand environment plays a key role. To enhance performance, athletesmay need to optimize both their pacing strategy and running technique.Pacing strategy indicates how athletes distribute their effort across a race,to cover a given distance in the shortest time possible. Uphill sectionsrequire a high fitness level, whilst downhill sections require high technicalskills. Investing more or less energy in certain sections or in a specific racestage may have different consequences on finish time.Spatiotemporal parameters concur to determine running speed. Most likely,differences in spatiotemporal parameters are elicited by a different runningtechnique. In this dissertation, technique has been investigated in termsof joint angles kinematics. Coordination and coordination variability representfurther tools to deeper understand the motion of an athlete. In biomechanics,coordination indicates how two body segments or joint anglesbehave with respect to each other, acting in synergy to produce a certainoutput. To carry out the same task, some coordination patterns maybe more efficient than others. Coordination variability indicates how thecoordination pattern differs between multiple repetitions of a given task, orbetween different individuals. Depending on the specific situation, a higheror lower coordination variability may indicate better or poorer motor control.To gain insights into pacing strategy and biomechanics in trail running, fourstudies have been performed. In the first study, we have sought to understandwhich pacing strategy results in the lowest finish time. In the secondstudy, we have sought to understand how spatiotemporal parameters andkinematics differs between faster and slower trail runners. In the thirdstudy, we have sought to understand how coordination and coordinationvariability differ between faster and slower trail runners. In the fourth study,we have sought to understand how spatiotemporal parameters and kinematicschange between initial and final race stage. Our findings may help coaches and practitioners to I) improve their strategy during competitions,II) target specific aspects of the movement so to enhance performance.submitted by Matteo Genitrini, M.Sc.Enthält Literaturverzeichnis auf Blatt 105-123Anhang enthält vier wissenschaftliche AufsätzeDissertation Paris Lodron-Universität Salzburg 202
- …
