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281.
A non-rotational (NR) shot is now a well-known scoring move in soccer. To execute the NR shot, it is necessary to deprive the ball of any rotational forces during the impact phase. To execute the NR shot, it is natural that the force vector acting from the foot would pass through the ball’s center of gravity; however, the coordinated motion of the lower limb joint’s angular displacement and the pelvis is still unclear. The aim of this study is to estimate the coordinated leg and pelvis motion during the NR shot as compared to that during instep kicking. Four right-leg dominant college league players were asked to perform a NR shot and an instep kick a total of 10 times each. Hip, knee, and ankle joint angular displacements in the sagittal plane and pelvis yaw and roll rotational motions during both types of kicks were calculated with 14 IR reflective markers using a 3D real-time motion analysis system with a 250-Hz sampling. The Euclidean distances of the joint space of the NR shot and the instep kick were also calculated to detect similarities in the coordinated motion of the lower limb. The results showed that the lower limb joint motions in the sagittal plane were not different; however, the pelvis roll and yaw motions were apparently different, and these phenomena could simulate a pendulum motion with changes in both the vertical and horizontal displacements. These results suggest that the coordinated motion of the lower limb joint’s angular displacement shows high similarity between the NR shot and the instep kick, and the pelvis roll and yaw synchronized orientation is essential for achieving the NR shot. 相似文献
282.
David S. Haydon Ross A. Pinder Paul N. Grimshaw William S. P. Robertson 《Sports Engineering》2016,19(3):177-184
Limited recommendations of wheelchair configurations for court sports have been identified in the published literature. To accommodate the wide range of impairments in wheelchair rugby, players are given a point score that reflects their impairment. Players have regularly been grouped as high-, mid-, or low-point players in research, with high-point players having greater levels of muscle function compared with other classifications. This research documented the wheelchair configurations of elite Australian wheelchair rugby players across classification groups. Significant differences (p < 0.05) were found for increased seat height and decreased seat depth for high-point players compared with low- and mid-point groups, respectively. Low-point players displayed reduced wheelchair mass compared with high- and mid-point players, as well as increased frame length. Camber angles showed no significant differences across the classification groups. The incorporation of anthropometric measures, such as the elbow angle at the top dead center, was also investigated. While elbow angle showed no significant differences, seat height-to-total arm length ratio was higher for high-point players. Participants also completed surveys detailing their perception of the effect of altering wheelchair configurations. It is suggested that wheelchair configurations should consider an individual’s anthropometrics, impairment, training history, and court role to promote optimal performance, with predictive modeling having the potential to reduce the associated time and cost. 相似文献
283.
Munjed Al Muderis Horst Heinrich Aschoff Belinda Bosley Guy Raz Ludger Gerdesmeyer Brendan Burkett 《Sports Engineering》2016,19(3):141-145
Lower limb amputees often experience complications with the use of conventional socket-type prostheses, which further reduce their already compromised ability to perform the activities of daily living, or to participate in sporting activities. During the last two decades, a new technology of direct skeletal attachment (osseointegration) of prosthesis to the femoral residuum has been developed. The aim of this research was to assess the implant design, surgery protocols, and functional testing of this new technology on the first 100 patients using the Integral Leg Prosthesis procedure. This new knowledge can guide future engineering developments of osseointegration within the sporting arena. Between 1999 and 2013, direct skeletal implantation was performed on 112 amputees, from two centres in Germany and Australia. From the experience of the surgical team, modifications were made to the implant design. This re-engineering of the implant has reduced the surgical revisions due to infection from 29 % with the early implant design down to 7 %. The functional testing of the 34 Australian cases were assessed pre- and 12 months post-implant with significant improvements of one complete K-scale; the Q-TFA measures increased (50.9–86.7), whilst the Timed Up and Go decreased significantly (12.43 s ± 3.89 to 8.03 s ± 2.80), and the 6 min walk increased (304.0–383.9 m). From these findings, osseointegration technology is realistically the way of the future for amputee athletes. Further refinement of the implant design and sports-specific functional testing are required to define the potential of this technology. 相似文献
284.
冯新灵 《绵阳师范学院学报》2003,22(5):57-60
通过深入考察研究绵阳旅游业系统,发现它属于对称性高、有序度较低的近平衡态系统.为使绵阳旅游业系统成为耗散结构系统,提出了其形成的必要条件和充分条件,并由其充要条件设计了独树一帜的“绵阳城市生态文化景区“. 相似文献
285.
286.
Chamila Nishanthi Edward David Asirvatham Md. Gapar Md. Johar 《Education and Information Technologies》2018,23(6):2587-2606
Blended learning emerged as the most popular instructional design strategy in the field of education since last decade to present date. In fact, it is well acknowledged that blended learning approach significantly elevate students’ engagement and competency in learning process. Despite immense potentiality, many countries are still lag behind adopting this instructional design, such as Sri Lanka. Therefore, the primary aims of this study are two fold, (a) to investigate the effect of blended learning and learners’ characteristics on students’ competence and (b) to investigate the effectiveness of blended learning in teaching Oriental Music. This study mainly carried out among the senior secondary schools students at Colombo, Sri Lanka. A mixed methods, experimental and survey, were carried out to test the effectiveness of blended learning and identifying the important factors for enhancing students’ competence in learning Oriental Music. Results of independent sample t-test confirmed that blended learning is effective in terms of improving students’ performance in learning Oriental Music. Similarly, regression analysis confirmed that attitude and motivation are the two most important determinants for improving students’ competence. This study fulfilled an existing research gap by utilizing blended learning to teach highly traditional abstract art. Results of the study contributes to the curriculum designing field with novel ideas to adapt in hybrid instructions to teach secondary level students effectively. The curriculum designers will make use of these findings during innovation and future researcher would be benefitted to overlook more possible platforms to deliver music instructions. It will help them to understand how their set objectives have been achieved in technology integrations and seek for improvement where necessary. 相似文献
287.
288.
李锋 《华东师范大学学报(哲学社会科学版)》2005,37(5):59-65
在刘勰看来,以往文学发展的状态的变化,其实质都是因为文质互为量变而形成的递进和衰退。准确地说,他认为:在商周之前,是一个递进的过程,而从商周以后则是一段衰退的历史。那么,商周就成了实际意义上文质彬彬的顶峰。然而,文质无法达到绝对的平衡,商周的“丽而雅”已经开始显示出文进质退的趋势。所以,不可否认,商周实际上又成为文胜质的拐点。文学的发展,在商周之后,便逐步走上了“从质至讹,弥近弥澹”的道路。 相似文献
289.
With advanced prediction modes of intra prediction, intra coding of H.264/AVC offers significant coding gains compared with previous video coding standards. It uses an important tool called Lagrangian rate-distortion optimization (RDO) technique to decide the best coding mode for a block, but the computational burden is extremely high. In this paper, we proposed an improved fast intra prediction algorithm including block type selection and mode decision algorithm based on analysis of edge feature of a block. Our algorithm filters out unlikely block type and candidate modes to reduce the RDO calculations. Experimental results showed that the proposed algorithm can reduce the computation complexity of intra prediction from 52.90% to 56.31%, with 0.04 dB PSNR degradation and 2% increase of bit rate. 相似文献
290.
5种东方百合过氧化物酶同工酶的分析 总被引:2,自引:0,他引:2
利用聚丙烯酰胺凝胶电泳的方法研究了5种东方百合:美人、西伯利亚、迈阿密、罗沙桃、斯达盖兹不同部位过氧化物酶的同工酶.结果表明:这5种东方百合均是花部分的同工酶谱带数多于茎、叶部分;美人、西伯利亚、罗沙桃3个品种的同工酶谱带具有很多的相似处。 相似文献