明日简讯     

刘洪宇 《海外英语》2003,(11)

Predicting the Wind 预测风向To sell their energy, wind-farm operators need to predict when they can deliver the power, but wind is skittish(多变的)and unpredictable. Researchers are hoping that artificial-intelligence techniques will make wind-energy forecasts more accurate. A method developed at Northern Ireland' s University of Ulster assesses past wind-flow patterns to predict  相似文献   

The culture of learning from mistakes: How employees handle mistakes in everyday work     

Christian Harteis  Johannes Bauer  Hans Gruber 《International Journal of Educational Research》2008,47(4):223-231

Workplace learning circumscribes processes leading to the development of competencies and skills through daily work. It is of increasing importance for many modern enterprises, which consider themselves as being learning organisations, to make use of the potential of their employees in order to be competitive within global markets. Dealing with mistakes is a particular strategic source of workplace learning for such organisations, because contemporary work often is so complex that mistakes cannot be avoided. A workplace culture of learning from mistakes stands to maximise them as effective learning experiences. Two empirical studies were conducted in order to investigate conditions of learning from mistakes in everyday work in modern enterprises. Study 1 assessed the role of individual mistake orientation using a questionnaire. Through the comparison of 52 managers and 108 working staff members the variability of learning from mistakes was investigated. Study 2 assessed how communities of practice deal with mistakes and what is done to prevent them occurring in future. Semi-structured interviews were conducted with 28 subjects, 14 managers and 14 working staff members. Study 1 revealed a greater appraisal of mistakes as opportunities for learning by managers, but no differences in related strategies and emotions. Study 2 revealed that mistakes are constructively dealt with, and that they are appraised as learning opportunities. Both studies indicate the presence of a culture of learning from mistakes in everyday work. Conclusions are drawn about organisational and personal prerequisites for this kind of workplace learning.  相似文献   

Instructional Quality Features in Videotaped Biology Lessons: Content-Independent Description of Characteristics     

Dorfner  Tobias  Förtsch  Christian  Boone  William  Neuhaus  Birgit J. 《Research in Science Education》2019,49(5):1457-1491

Research in Science Education - A number of studies on single instructional quality features have been reported for mathematics and science instruction. For summarizing single instructional quality...  相似文献   

Improving Students’ Information Problem-Solving Skills on the Web Through Explicit Instruction and the Use of Customized Search Software     

Andrea Ibieta  J. Enrique Hinostroza  Christian Labbé 《Journal of Research on Technology in Education》2019,51(3):217-238

Abstract

Research shows that students face a range of difficulties when using the Internet to solve information problems. Using a quasi-experimental design, we tested a strategy to improve Chilean 10th graders’ skills for information problem solving using the Internet (IPS-I). The intervention was based on a workshop in which students learned IPS-I strategies and solved information problems using a customized Internet search software package. Results showed that members of the experimental group changed their search behavior and improved the quality of their products. However, no correlation between the number of search actions and product quality was found. Based on this, we highlight the potential of combining teaching strategies to improve specific search skills and the use of customized search tools with embedded functionalities that foster good search techniques.  相似文献   

Sleep monitoring of a six-day microcycle in strength and high-intensity training     

Sarah Kölling  Thimo Wiewelhove  Christian Raeder  Stefan Endler  Alexander Ferrauti  Tim Meyer 《European Journal of Sport Science》2016,16(5):507-515

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Post-warmup strategies to maintain body temperature and physical performance in professional rugby union players     

Daniel J. West  Mark Russell  Richard M. Bracken  Christian J. Cook  Tibault Giroud  Liam P. Kilduff 《Journal of sports sciences》2016,34(2):110-115

We compared the effects of using passive-heat maintenance, explosive activity or a combination of both strategies during the post-warmup recovery time on physical performance. After a standardised warmup, 16 professional rugby union players, in a randomised design, completed a counter-movement jump (peak power output) before resting for 20 min and wearing normal-training attire (CON), wearing a passive heat maintenance (PHM) jacket, wearing normal attire and performing 3 × 5 CMJ (with a 20% body mass load) after 12 min of recovery (neuromuscular function, NMF), or combining PHM and NMF (COMB). After 20 min, participants completed further counter-movement jump and a repeated sprint protocol. Core temperature (T_core) was measured at baseline, post-warmup and post-20 min. After 20 min of recovery, T_core was significantly lower under CON and NMF, when compared with both PHM and COMB (P < 0.05); PHM and COMB were similar. Peak power output had declined from post-warmup under all conditions (P < 0.001); however, the drop was less in COMB versus all other conditions (P < 0.05). Repeated sprint performance was significantly better under COMB when compared to all other conditions. Combining PHM with NMF priming attenuates the post-warmup decline in T_core and can positively influence physical performance in professional rugby union players.  相似文献   

Similar results for face mask versus mouthpiece during incremental exercise to exhaustion     

Dale R. Wagner  Nicolas W. Clark 《Journal of sports sciences》2016,34(9):852-855

Investigations in the 1990s evaluated the influence of breathing assemblies on respiratory variables at rest and during exercise; however, research on new models of breathing assemblies is lacking. This study compared metabolic gas analysis data from a mouthpiece with a noseclip (MOUTH) and a face mask (MASK). Volunteers (7 males, 7 females; 25.1 ± 2.7 years) completed two maximal treadmill tests within 1 week, one MOUTH and one MASK, in random order. The difference in maximal oxygen consumption (VO_2max) between MOUTH (52.7 ± 11.3 ml · kg^?1 · min^?1) and MASK (52.2 ± 11.7 ml · kg^?1 · min^?1) was not significant (P = 0.53). Likewise, the mean MOUTH–MASK differences in minute ventilation (V_E), fraction of expired oxygen (FEO₂) and carbon dioxide (FECO₂), respiration rate (RR), tidal volume (V_t), heart rate (HR), and rating of perceived exertion (RPE) at maximal and submaximal intensities were not significant (P > 0.05). Furthermore, there was no systematic bias in the error scores (r = ?0.13, P = 0.66), and 12 of the 14 participants had a VO_2max difference of ≤3 ml · kg^?1 · min^?1 between conditions. Finally, there was no clear participant preference for using the MOUTH or MASK. Selection of MOUTH or MASK will not affect the participant’s gas exchange or breathing patterns.  相似文献   

Pre-training perceived wellness impacts training output in Australian football players     

Tania F. Gallo  Stuart J. Cormack  Tim J. Gabbett  Christian H. Lorenzen 《Journal of sports sciences》2016,34(15):1445-1451

The impact of perceived wellness on a range of external load parameters, rating of perceived exertion (RPE) and external load:RPE ratios, was explored during skill-based training in Australian footballers. Fifteen training sessions involving 36 participants were analysed. Each morning before any physical training, players completed a customised perceived wellness questionnaire (sleep quality, fatigue, stress, mood and muscle soreness). Microtechnology devices provided external load (average speed, high-speed running distance, player load and player load slow). Players provided RPE using the modified Borg category-ratio 10 RPE scale. Mixed-effect linear models revealed significant effects of wellness Z-score on player load and player load slow. Effects are reported with 95% confidence limits. A wellness Z-score of ?1 corresponded to a ?4.9 ± 3.1 and ?8.6 ± 3.9% reduction in player load and player load slow, respectively, compared to those without reduced wellness. Small significant effects were also seen in the average speed:RPE and player load slow:RPE models. A wellness Z-score of ?1 corresponded to a 0.43 ± 0.38 m·min^?1 and ?0.02 ± 0.01 au·min^?1 change in the average speed:RPE and player load slow:RPE ratios, respectively. Magnitude-based analysis revealed that the practical size of the effect of a pre-training perceived wellness Z-score of ?1 would have on player load slow was likely negative. The results of this study suggests that monitoring pre-training perceived wellness may provide coaches with information about the intensity of output that can be expected from individual players during a training session.  相似文献   

Mobilities at Play: The Local Embedding of Transnational Connections in West African Football Migration     

Christian Ungruhe 《国际体育史杂志》2016,33(15):1767-1785

Abstract

So far, academic contributions have widely framed football in Africa as a means for migration from a western point of view. At a time, they presented particular and one-dimensional understandings of transnational links in the realm of football migration between Africa and Europe. Macro-level perspectives which mostly focus on African exploitation and dependency and more recently those that take the players’ agency into account reproduce a Eurocentric view of the phenomenon, while disregarding its local perceptions in African settings. Thus, despite the recent shift from a macro- to a micro-level perspective there is still an analytical gap between the ambitions and experiences of migrating players and economic power relations at play on the one hand and the socio-cultural embedding of the transnational connections in football migration on the other. In order to understand why and how football mobilities are indeed linked to ‘the transnational’ in migration there is a need to localize the phenomenon and investigate how local understandings of migration and mobility are lived and expressed in a transnational sport like football. By taking data from fieldwork among West African football migrants, the paper thus shows the local embedding of transnational football migration practices in the West African context.  相似文献   

Empirische Befunde zu Beeinflussungsversuchen bei Schiedsrichtern im Amateurfußball     

Christian Rullang  Freya Gassmann  Eike Emrich  Christian Pierdzioch 《Sportwissenschaft》2016,46(3):232-240

In recent years unfair competition and match fixing have become an increasing focus of public attention. Uncovered instances of match fixing influence the integrity of football. In the field of professional football there are well-known cases, such as the Calciopoli scandal in Italy and the case of the German referee Robert Hoyzer, where referees were involved in match fixing. However, so far little is known about how often attempts are made to influence referees and their decisions in amateur football in Germany. Data from a large scale survey of referees (n = 4813) showed that approximately 10?% of referees in amateur football have already been approached in an attempt to influence their decisions by offers of money or non-cash benefits. Results of logistic regressions show various correlats of being approached for match fixing by offers of money or non-cash benefits. The probability of being approached increases with the duration of referee activity, the number of games refereed per year, and decreases with age.  相似文献