Training consisting of numerous repetitions performed as closely as possible to ideal techniques is common in sports and every-day tasks. Little is known about fatigue-related technique changes that emerge at different timescales when repeating complex actions such as a karate front kick. Accordingly, 15 karatekas performed 600 kicks (1 pre-block and 9 blocks). The pre-block comprised 6 kicks (3 with each leg) at maximum intensity (K-100%). Each block comprised 60 kicks (10 with each leg) at 80% of their self-perceived maximum intensity (K-80%) plus 6 K-100%. In between blocks, the participants rested for 90 seconds. Right leg kinematics (peak joint angles, peak joint angular velocities, peak joint linear resultant velocities, and time of occurrence of peaks) and kick duration corresponding to the K-80% were measured resulting in numerous variations with fatigue. At the timescale of tens of seconds, the changes involved variables that were related to velocity of execution (slowed down), while variables related to movement form were hardly affected. At the timescale of tens of minutes, the opposite results were observed. These findings challenge the long-standing rationale underlying repetitive training, suggesting instead that such involuntary variations in technique might play a crucial role in motor skill training 相似文献
Force plates represent the “gold standard” in measuring running kinetics to predict performance or to identify the sources of running-related injuries. As these measurements are generally limited to laboratory analyses, wireless high-quality sensors for measuring in the field are needed. This work analysed the accuracy and precision of a new wireless insole forcesensor for quantifying running-related kinetic parameters. Vertical ground reaction force (GRF) was simultaneously measured with pit-mounted force plates (1?kHz) and loadsol® sensors (100?Hz) under unshod forefoot and rearfoot running-step conditions. GRF data collections were repeated four times, each separated by 30 min treadmill running, to test influence of extended use. A repeated-measures ANOVA was used to identify differences between measurement devices. Additionally, mean bias and Bland–Altman limits of agreement (LoA) were calculated. We found a significant difference (p?® devices for these parameters. For these same parameters, the LoA analysis showed that 95% of all measurement differences between insole and force plate measurements were less than 12%, demonstrating high precision of the sensors. However, highly dynamic behaviour of GRF, such as force rate, is not yet sufficiently resolved by the insole devices, which is likely explained by the low sampling rate. 相似文献
Most firms use secrecy to protect their knowledge from potential imitators. However, the theoretical foundations for secrecy have not been well explored. We extend knowledge protection literature and propose theoretical mechanisms explaining how information visibility influences the importance of secrecy as a knowledge protection instrument. Building on mechanisms from information economics and signaling theory, we postulate that secrecy is more important for protecting knowledge for firms that have legal requirements to reveal information to shareholders. Furthermore, we argue that this effect is contingent on the location in a technological cluster, on a firm’s investment in fixed assets and on a firm’s past innovation performance. We test our hypotheses using a representative sample of 683 firms in Germany between 2005 and 2013. Our results support the moderation effect of a technological cluster and a firm’s investment in fixed assets. Our findings inform both academics and managers on how firms balance information disclosure requirements with the use of secrecy as a knowledge protection instrument. 相似文献
Observed process quality in infant/toddler classrooms was compared in Germany (n = 75) and the USA (n = 219). Process quality was assessed with the Infant/Toddler Environment Rating Scale(ITERS) and parent attitudes about ITERS content with the ITERS Parent Questionnaire (ITERSPQ). The ITERS had comparable reliabilities in the two countries and similar factors were found. Content validity of the ITERS is supported in both countries by similarly high ITERSPQ importance scores. ITERS classroom mean scores are similar (Germany = 3.21; USA = 3.36), but a higher US standard deviation is found. A discriminant analysis revealed differences between countries on a bipolar dimension, with US programs characterized by higher scores on custodial issues while German programs have higher scores on educational aspects. Spearman rank order correlations were completed on ITERSPQ importance scores and observed ITERS scores, showing an association only in the USA. Results are discussed in terms of the parental values and infrastructures found in the two countries.
La qualité de processus observée dans les salles de classe des Enfants/Petits Enfants a été comparée en l’Allemagne (n = 75) et aux Etats‐Unis (n = 219). La qualité de processus a été évaluée avec l’Échelle d’Évaluation de l’Environnement des Enfants/Petits Enfants (ITERS) et les attitudes des parents au sujet du contenu de l’ITERS avec le Questionnaire d’ITERS pour les Parents (ITERSPQ). L’ITERS a eu fiabilités comparables dans les deux pays et des facteurs semblables ont été trouvés. La validité du contentu de l’ITERS est soutenue dans les deux pays par des points sur l’importance d’ITERSPQ pareillement hauts. Les points moyens ITERS de la salle de classe sontsemblables, (Allemagne = 3.21 ; Etats‐Unis = 3.36), mais un écart type plus élevé pour les Etats‐Unis est trouvé. Une analyse discriminante a indiqué des différences entre les pays sur une dimension bipolaire, avec les programmes des Etats‐Unis caractérisés par de points plus hauts sur la question de la garde tandis que les programmes allemands ont de points plus hauts sur des aspects éducatifs. Des corrélations Spearman d’ordre de rang ont été accomplies sur les points d’importance ITERSPQ et on a observé des points d’ITERS montrer une association seulement pour les Etats‐Unis. Des résultats sont discutés en termes de valeurs et infrastructures parentales trouvées dans les deux pays.
La calidad de proceso observada en salas de clase de infantes/niños pequeños fue comparada en Alemania (n = 75) y los E.E.U.U. (n = 219). La calidad de proceso fue determinada con la Escala para Evaluar el Ambiente del Infante/ Niño pequeño (ITERS) y las actitudes de los padres hacia el contenido del ITERS con el Cuestionario ITERS para los Padres (ITERSPQ). El ITERS tenía confiabilidades comparables en los dos países y se encontraron factores similares. La validez del contenido del ITERS es apoyada en ambos países por los puntajes sobre la importancia del ITERSPQ que son semejantemente altos. Los puntajes medios ITERS de la sala de clase son similares, (Alemania = 3.21; E.E.U.U. = 3.36), pero se encuentra una desviación estándar más alta con los E.E.U.U. Un análisis discriminante reveló diferencias entre los países en una dimensión bipolar, con los programas de los E.E.U.U. caracterizados por puntajes más altos en el área de la custodia mientras que los programas alemanes tienen puntajes más altos en los aspectos educativos. Las correlaciones Spearman sobre el orden de rango fueron completadas en los puntajes sobre la importancia de ITERSPQ y se observaron puntajes de ITERS demostrando una asociación solamente en los E.E.U.U. Los resultados se discuten en términos de los valores parentales e infraestructuras encontradas en los dos países. 相似文献
Der vorliegende Beitrag besch?ftigt sich unter Bezugnahme auf einen systemtheoretischen Kommunikationsbegriff mit der (p?dagogischen)
Strukturierung des Lernens Erwachsener. Er geht von der These aus, dass die P?dagogisierung des lernbezogenen Umgangs mit
Wissen im Erwachsenenalter unsichtbar (gemacht) wird. Auf der Grundlage eines abgeschlossenen DFG-Projekts werden unterschiedliche
Formen p?dagogischer Kommunikation dargestellt und das in ihren Settings, ihrer kommunikativen Verfasstheit und den Mustern
ihrer Strukturierung eingelagerte Invisibilisierungspotenzial herausgearbeitet. Vor diesem Hintergrund wird das Konzept des
Lebenslangen Lernens als eine entwickelte Form des Umgangs mit dem Paradox der (Un-)Sichtbarkeit p?dagogischer Kommunikation
interpretiert. Was diese Institutionalisierungsform des Lernens kennzeichnet, ist somit eine doppelt gegenl?ufige Gleichzeitigkeit
von Visibilisierung und Invisibilisierung. 相似文献
This paper describes findings of a longitudinal study that was carried out to examine relationships among different aspects
of young children's cognitive development, namely, theory of mind, metacognitive vocabulary, and metamemory, which seem theoretically
connected but so far have not been studied simultaneously. In total, 174 children were included in the present analyses who
were about 4;6 years of age at the first measurement point. Children were tested at four time points, separated by a testing
interval of approximately half a year. At the first time of testing, children completed a set of theory of mind tasks. At
each of the following measurement points, measures of metacognitive vocabulary and general vocabulary as well as metamemory
were given. Overall, the findings show that theory of mind performance assessed at the age of 4;6 predicts metacognitive knowledge
assessed about one and a half years later. Furthermore, they point to a reciprocal relationship between metacognitive vocabulary
and metamemory in that comprehension of metacognitive vocabulary predicted later metamemory and, conversely, metamemory significantly
predicted later comprehension of metacognitive verbs.
This research was supported by a grant from the German Research Foundation (SCHN 315 /20–7) to the German Research Group on
Cognitive Development. 相似文献
Studying abroad is one way in which university students can develop personal capital and distinguish themselves in an increasingly congested graduate labour market. Data show that studying abroad indeed provides employment benefits, with evidence pointing to even greater positive effects for students from low socio‐economic status backgrounds. Focusing on a group of Canadian students about to embark on a study exchange, we find no evidence that career‐instrumental reasons played a role in participants’ decisions to study abroad. Rather, they sought personal growth and escape from the everyday frustrations of being an undergraduate student. We argue, however, that these motivations nonetheless have to be understood as strategic, since going on a study exchange abroad allows students to escape temporarily, while ‘staying in the game’ of becoming credentialed at home. We discuss the role of socio‐economic status, as well as the policy implications of these findings. 相似文献
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