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Accurate time measurement is essential to temporal analysis in sport. This study aimed to (a) develop a new method for time computation from surveyed trajectories using a high-end global navigation satellite system (GNSS), (b) validate its precision by comparing GNSS with photocells, and (c) examine whether gate-to-gate times can provide more detailed information about alpine skiing performance. The results demonstrated small mean time differences with no systematic bias, with a velocity dependent scatter of time differences, which diminished at higher velocities. Furthermore, the multiple gate-to-gate and lag times demonstrated that the GNSS enabled a more detailed analysis compared to photocells. The measurements using GNSS showed high validity and potential as a tool for more specific analysis of performance in skiing. 相似文献
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Börje Holmberg 《Distance Education》1985,6(1):79-90
This paper is about how to teach a foreign language at a distance, i.e. how to support the learning of a foreign language by students who are not taught by teachers face‐to‐face. Much experience about this has been collected by correspondence schools and similar organisations. Among the public bodies of importance here should be mentioned the state‐owned and state‐run French Centre National d'Enseignement par Correspondence and Athabasca University in Alberta, Canada. Little seems to have been published about teaching and learning foreign languages at a distance, although Rousseau 1977 and contributions to ICDE and EHSC conferences (in 1982 and 1979) have surveyed essential problem areas. Experiences of teaching English as a foreign language provide the basis from which many considerations are examined. 相似文献
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Gilbert de Landsheere Marten Groen John Biggs John F. Willatt David Thomas Clare Burstall Robin Russell J. R. Barr Gerhard Pause Donald E. Super John B. Biggs Alan C. Purves Klaus Schleicher Herbert A. Thelen Neville Postlethwaite Börje Holmberg Kenneth Austwick Sven Hilding A Group of Scottish Physics Teachers 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1967,13(1):90-123
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Billy Sperlich Matthias Haegele Silvia Achtzehn John Linville Hans-Christer Holmberg Joachim Mester 《Journal of sports sciences》2013,31(6):609-614
Abstract Three textiles with increasing compressive surface were compared with non-compressive conventional clothing on physiological and perceptual variables during sub-maximal and maximal running. Fifteen well-trained endurance athletes (mean ± s: age 27.1 ± 4.8 years, [Vdot]O2max 63.7 ± 4.9 ml · min?1 · kg?1) performed four sub-maximal (~70%[Vdot]O2max) and maximal tests with and without different compression stockings, tights, and whole-body compression suits. Arterial lactate concentration, oxygen saturation and partial pressure, pH, oxygen uptake, and ratings of muscle soreness were recorded before, during, and after all tests. In addition, we assessed time to exhaustion. Sub-maximal (P = 0.22) and maximal oxygen uptake (P = 0.26), arterial lactate concentration (P = 0.16; 0.20), pH (P = 0.23; 0.46), oxygen saturation (P = 0.13; 0.26), and oxygen partial pressure (P = 0.09; 0.20) did not differ between the types of clothing (effect sizes = 0.00–0.45). Ratings of perceived exertion (P = 0.10; 0.15), muscle soreness (P = 0.09; 0.10) and time to exhaustion (P = 0.16) were also unaffected by the different clothing (effect sizes = 0.28–0.85). This was the first study to evaluate the effect on endurance performance of different types of compression clothing with increasing amounts of compressive surface. Overall, there were no performance benefits when using the compression garments. 相似文献
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Niels Jensby Nedergaard Frederik Heinen Simon Sloth Hans-Christer Holmberg 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(3):273-286
An effective start enhances an athlete's chances of success in ski cross competitions. Accordingly, this study was designed to investigate the biomechanics of start techniques used by elite athletes and assess the influence of different start environments. Seven elite ski cross athletes performed starts indoors on a custom-built ramp; six of these also performed starts on an outdoor slope. Horizontal and vertical forces were measured by force transducers located in the handles of the start gate and a 12-camera motion capture system allowed monitoring of the sagittal knee, hip, shoulder, and elbow kinematics. The starting movement involved Pre, Pull, and Push phases. Significant differences between body sides were observed for peak vertical and resultant forces, resultant impulse, and peak angular velocity of the shoulder joint. Significantly lower peak vertical forces (44 N), higher resultant impulse (0.114 Ns/kg), and knee joint range of motion (12°) were observed indoors. Although movement in the ski cross start is generally symmetrical, asymmetric patterns of force were observed among the athletes. Two different movement strategies, i.e. pronounced hip extension or more accentuated elbow flexion, were utilised in the Pull phase. The patterns of force and movement during the indoor and outdoor starts were similar. 相似文献
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Börje Holmberg 《Open Learning》2013,28(3):29-33
What does research tell us about the best ways to encourage students to adopt the most sensible approaches to learning, and what do we know about designing distance teaching so that it brings about the deepest understanding and active learning? Professor Börje Holmberg was Director General of Hermods, the famous Swedish Correspondence College, before joining the FernUniversitat at Hagen in West Germany where he is head of the Central Institute for Research in Distance Education. 相似文献
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Developing constructive and non‐threatening feedback 总被引:1,自引:1,他引:0
Börje Holmberg 《Open Learning》2013,28(2):44-45