1,720,988 research outputs found
Motion analysis in sports monitoring techniques: assessment protocols and application to racewalking / Monitoraggio del gesto sportivo con tecniche di motion analysis: protocolli di valutazione e applicazione alla marcia agonistica
No full textThe aim of this study was to propose guidelines for the proper use of data from motion analysis technologies. The field of investigation concerned the monitoring of individual characteristics in sports movements. The objective was to: determine the number of trials needed to attain stability of individual biomechanical parameters and for a robust description of individual peculiarities; implement a feedback process that could provide coaches and physicians with user-friendly information that might help them in the training or clinical context. Racewalking was chosen as the paradigmatic movement for investigation.
Forty racewalking trials were recorded for each of the 7 (inter) national-rank athletes involved in the study. An optoelectronic motion-analysis system, a force platform, and the SAFLo biomechanical model were used to measure the segmental kinematics and kinetics. Indications from expert coaches were used to define and estimate biomechanical parameters for describing the racewalking technique. The “sequential estimation procedure” was used to assess the stability of individual parameters. The minimum number of trials needed to attain stability of individual parameters and a consistent descrip¬tion of individual peculiarities was 15. A set of graphical interfaces was created to visualize the performance-related biomechanical measures and to present the feedback of user-friendly biomechanical information to the end users (coaches, athletes, physicians).
This study constitutes first step toward the application of modern motion-analysis technologies to moni¬toring an athlete’s individual characteristics. As an interdisciplinary methodological contribution, the study demon¬strates the potential use of these instruments in the evaluation of performance-related motor factors in sports (training, individual skills, athletic condition, motor learning) and in clinical practice (injury prevention, support to medical intervention, post-injury monitoring)
Application of functional principal component analysis in race walking: an emerging methodology.
No full textThis study considered the problem of identifying and evaluating the factors of individual performance during race walking. In particular, the study explored the use of functional principal component analysis (f-PCA), a multivariate data analysis, for assessing and classifying the kinematics and kinetics of the knee joint in competitive race walkers. Seven race walkers of international and national level participated to the study. An optoelectronic system and a force platform were used to capture three-dimensional kinematics and kinetics of lower limbs during the race walking cycle. Functional principal component analysis was applied bilaterally to the sagittal knee angle and net moment data, because knee joint motion is fundamental to race walking technique. Scatterplots of principal component scores provided evidence of athletes' technical differences and asymmetries even when traditional analysis (mean +/- s curves) was not effective. Principal components provided indications for race walkers' classification and identified potentially important technical differences between higher and lower skilled athletes. Therefore, f-PCA might represent a future aid for the fine analysis of sports movements, if consistently applied to performance monitoring
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Electrical stimulation versus voluntary training of quadriceps muscles in soccer players: effects on muscle performance
No full textDispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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