Kinematic analysis of the drag flick in field hockey     

Rony Ibrahim  Gert S. Faber  Jaap H. van Dieën 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):45-57

Attaining high speed of the stick head and consequently of the ball is essential for successful performance of the drag flick in field hockey, but the coordination pattern used to maximise stick head speed is unknown. The kinematics of the drag flick was studied in ten elite hockey players who performed twenty shots each towards a target located 1.5 m high. A 150 Hz active marker motion analysis system was used, alongside two force plates to detect foot touchdown. Angular velocity and contribution to stick endpoint speed of upper body joints were analysed. Repeated measures ANOVA was used to compare timing of onset and peak angular velocities between joints. Participants used a kinematic pattern that was close to a proximal-to-distal sequence. Trunk axial rotation and lateral rotation towards the target, right wrist flexion and left wrist extension were the main contributors to stick endpoint speed. Coaches should emphasise trunk rotations and wrist flexion and extension movements for maximising stick head speed. Given the high level of the participants in this study, the coordination of joints motions, as reported here, can serve as a guideline for drag flick training.  相似文献   

Heritage sporting events: theoretical development and configurations     

Joël Pinson 《Journal of Sport Tourism》2017,21(2):133-152

ABSTRACT

Although sports heritage is increasingly recognized as a potential catalyst of tourism, heritage sporting events (HSEs) are still an emerging concept in the academic literature. Notions that associate sports events and heritage remain rare, and are usually analysed through the scope of nostalgia sport tourism. This can be partly explained by an inclination to associate the notion of heritage with conventional ideas about folklore and traditional culture. Through a constructivist approach of heritage, this contribution argues that contemporary sports events, which would generally have competition as their primary focus, might also be perceived as HSEs. A comprehensive framework, built on a multi-disciplinary literature review, is presented to show the process that transforms an initial resource (a sports event) into an accomplished resource (a HSE), which might represent a competitive advantage for the territory. A qualitative–comparative analysis is conducted among 24 sports events in the French-speaking part of Switzerland, to observe the configurations of HSEs and understand which characteristics are necessary for the perceptions of a sports event as a heritage good. Interestingly, this contribution shows that if the event needs to be sustainable in the territory to be perceived as a HSE, it is not sufficient. Indeed, a differentiation strategy should be set up to distinguish the event from other more or less similar events, to be perceived as an authentic feature of the territory by the local population.  相似文献   

A method of providing accurate velocity feedback of performance on an instrumented kayak ergometer     

Mickaël Begon  Olivier Mourasse  Patrick Lacouture 《Sports Engineering》2009,11(2):57-65

On a kayak ergometer, an accurate simulation of the athlete-paddle-kayak system kinematics is essential for analysing the relationship between technique and performance. The purpose of this study was to establish a strong relationship between performances on flatwater and performances on an ergometer by means of propulsive force measurement and drag models. Two trials were performed by 12 kayakers in which they were first timed over 250 m of flatwater kayaking (the reference test) and were then asked to perform a trial of the same duration on the ergometer with the same perceived physical exertion. Three techniques for measuring propulsive force and three drag models generated nine combinations, which were all evaluated for their ability to estimate kayak velocity. For each combination, the distance covered by the athlete on the ergometer was simulated. A kayakers’ ergometer ranking was based on the average velocity in the ergometer trial. Both distance and ranking were compared to the on-water results. The simulation with the best combination of force measurement and drag model gave an accurate estimate of distance (253 ± 10.5 vs. 250 m) and ranking compared to the reference test.  相似文献   

石中瑰宝 造化为灵——“四大名石”之首灵璧石品鉴     

尕丁  贺鸿磊 《收藏》2007,(12):142-144

承万古幽石之遗韵 一般而言，收藏者中传统之士多好古，大璞内藏，发古阐幽；新潮之人则好奇，度奇处巧，迁想妙得。若论五彩迷目、千姿弄巧之观赏石中何为传统与好古，自当首推奇中含幽之“四大名石”。  相似文献   

吉地淘宝 感悟其绝——记书画收藏投资家贾绍俭     

尕丁 《收藏》2007,(2):142-147

艰辛之中司商机 20世纪70年代后期，中国社会迎来了改革开放的春风。当人们从长期身处的计划经济模式中向外四处观望时，保官运亨通、安贫的观念仍然盘桓在绝大多数人的头脑。勇于迎接市场经济大潮的搏击者，在当时则显得十分另类，贾绍俭就是其中的一位。  相似文献   

Validation of the Instructional Materials Motivation Survey (IMMS) in a self‐directed instructional setting aimed at working with technology          下载免费PDF全文

Nicole Loorbach  Oscar Peters  Joyce Karreman  Michaël Steehouder 《British journal of educational technology : journal of the Council for Educational Technology》2015,46(1):204-218

The ARCS Model of Motivational Design has been used myriad times to design motivational instructions that focus on attention, relevance, confidence and satisfaction in order to motivate students. The Instructional Materials Motivation Survey (IMMS) is a 36‐item situational measure of people's reactions to instructional materials in the light of the ARCS model. Although the IMMS has been used often, both as a pretest and a posttest tool serving as either a motivational needs assessment prior to instruction or a measure of people's reactions to instructional materials afterward, the IMMS so far has not been validated extensively, taking statistical and theoretical aspects of the survey into account. This paper describes such an extensive validation study, for which the IMMS was used in a self‐directed instructional setting aimed at working with technology (a cellular telephone). Results of structural equation modeling show that the IMMS can be reduced to 12 items. This Reduced Instructional Materials Motivation Survey IMMS (RIMMS) is preferred over the original IMMS. The parsimonious RIMMS measures the four constructs attention, relevance, confidence and satisfaction of the ARCS model well, and reflects its conditional nature.  相似文献   

What and how teacher educators prefer to learn     

Jurriën Dengerink  Mieke Lunenberg  Quinta Kools 《师资教育杂志》2015,41(1):78-96

In which areas and domains do individual teacher educators prefer to work on their professional development? What kind of learning activities do they want to take on and with whom? Are there significant differences in these preferences between teacher educators? This article reports on a recent survey (N = 268) about the professional development of teacher educators and differences in learning preferences between less and more experienced teacher educators and between university-based and school-based teacher educators. Findings show, for example, that while most university-based teacher educators were mainly interested in improving their teaching, less experienced school-based teacher educators were more focussed on aspects such as coaching skills. In this study, ‘learning profiles’ have been developed for four categories of teacher educators. These profiles may help to create more meaningful arrangements for teacher educators’ initial education and further professional development in a context where teacher education is required to have a more school-based as well as a more research-based orientation.  相似文献   

Rater strategies for reaching agreement on pupil text quality     

Lennart Jølle 《Assessment in Education: Principles, Policy & Practice》2015,22(4):458-474

Novice members of a Norwegian national rater panel tasked with assessing Year 8 pupils’ written texts were studied during three successive preparation sessions (2011–2012). The purpose was to investigate how the raters successfully make use of different decision-making strategies in an assessment situation where pre-set criteria and standards give a rather strict framework. The data sources were the raters’ pair assessment dialogues. The analysis shows that the raters use a ‘shared standards strategy’, but when reaching agreement on text quality they also seem to make very good use of assessment strategies related to their work as writing teachers. Moreover, asymmetries in knowledge and participation among raters contribute to creating an image of writing assessment as a challenging hermeneutic practice. It is suggested that future rater preparation would gain from being attentive to the internalised assessment practices teachers bring to the fore when working as raters.  相似文献   

DUAL TREATMENTS AS STARTING POINT FOR INTEGRATIVE PERCEPTIONS IN TEACHING MATHEMATICS     

Svjetllana Kërënxhi  Pranvera Gjoci 《International Journal of Science and Mathematics Education》2015,13(4):793-809

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Incorporating AI and learning analytics to build trustworthy peer assessment systems     

Ali Darvishi  Hassan Khosravi  Shazia Sadiq  Dragan Gašević 《British journal of educational technology : journal of the Council for Educational Technology》2022,53(4):844-875

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