膝关节运动的生物力学特性研究

利用X线摄片测量,并运用STK录像分析系统,对膝关节运动的生物力学特性进行了定量的研究,测量了动态、静态时的膝关节最大运动幅度以及参与膝关节运动的各肌肉长度变化、力臂变化。认为膝关节力学结构无性别差异。指出了各肌肉参与程度及达到最大力臂的位相顺序。     

气体扩散实验的新设计

介绍了气体扩散实验存在的问题和改进的方法。     

细粒度并行归一化部分失真运动估计

移动视频编码应用对实时性要求越来越高,传统编码器中使用的串行运动估计算法难以满足实时编码要求.本文并行化移动编码中典型的运动估计算法--归一化部分失真搜索.采用比帧和宏块更小的候选块作为并行粒度,保持归一化部分失真快速排除非最佳候选块优势,同时充分利用多核计算资源.4核CPU平台上实验结果表明,相比串行算法,该并行算法在计算量增加不超过1.2%的前提下,实现了3.88至3.96的加速比.     

支持动态搜索区域的运动估计硬件结构设计与优化

提出一种支持动态搜索区域的可变块大小运动估计硬件结构, 弥补固定大小搜索区域的不足, 可同时降低外存带宽、计算复杂度和功耗. 使用循环分布式存储结构来支持动态搜索区域的数据存取. 此外, 对耗时的SAD(sum of absolute differences)计算阵列进行均衡的流水线划分和加法逻辑优化. 实现结果表明, 相比同类设计, 该设计以少量的吞吐率损失, 换取面积效率和功耗效率的明显提高.     

论多元智能理论在定向运动训练中的应用

将多元智能理论应用于定向运动训练中,介绍多元智能理论的基本内涵、定向运动的概念和内涵,论述多元智能理论中的八种智能在定向运动中的分布,并从训练的实际出发,提出利用多元智能理论进行定向运动训练的具体训练方法,旨在为促进定向运动训练质量的提高及训练方法改革提供有益的参考与借鉴。     

MATLAB仿真在交流调压调速系统实验教学中的应用

在＂运动控制系统＂课程实验教学中,采用面向电气原理结构图的仿真方法,利用MATLAB环境中的SIMULINK仿真模块实现了晶闸管异步电动机交流调压调速系统的仿真建模及其分析.利用该模型对交流调压调速系统的性能进行了详细的仿真实验分析,得到和理论分析一致的结果.由于仿真模型是图形化的,具有直观可视性,用于实验教学中,学生易于理解系统的组成结构及其工作过程,有助于学生对交流调压调速系统的全面理解和学习.     

The Relationship of Locus of Control and Metacognitive Knowledge of Math with Math Achievements

The purpose of the research was to examine the correlation between locus of control and metacognitive knowledge in math and math achievement among students with learning disabilities. We examined 30 eighth grade pupils with learning disabilities and 30 other pupils all of whom studied in a heterogeneous class in a public school in order to better understand the extent to which the variables: metacognitive knowledge, locus of control and achievement in math differed in the two populations. The pupils answered three questionnaires: the first was designed to study the locus of control, the second, to investigate metacognitive knowledge and the third, to measure math achievement. The findings of this study indicate that the higher the level of the internal locus of control, the higher the use of metacognitive knowledge. Furthermore, higher levels of internal locus of control and higher use of metacognitive knowledge resulted in increased math achievement.     

Activity and recovery cycles and skill involvements of successful and unsuccessful elite rugby league teams: A longitudinal analysis of evolutionary changes in National Rugby League match-play

We investigated changes in activity and recovery cycles and skill involvements: (1) during National Rugby league (NRL) match-play from 2004 to 2014 and (2) among successful and unsuccessful teams over the same period. Teams were divided into 4 tiers according to final ladder position: (A) 1st–4th, (B) 5th–8th, (C) 9th–12th and (D) 13th–16th. Total, mean and maximum ball-in-play time decreased, while recovery time increased from 2004 to 2014. Offensive and defensive skill involvements changed differentially over time with moderate to large reductions in the number of play-the-balls, offloads and missed tackles, and moderate to large increases in the number of passes, tackles made and ineffective tackles. The gap between Tier A and Tier D decreased for mean activity time and the proportion of short (<45 s) ball-in-play periods. Conversely, the gap between Tier A and Tier D increased for skill involvements, with Tier A completing more play-the-balls, and Tier D performing a greater number of offloads, and total, missed and ineffective tackles. Our results demonstrate the decreasing ball-in-play demands of NRL competition over 11 seasons. However, our data also highlight the narrowing gap in ball-in-play demands, and increasing gap in skill involvements between the top tier and bottom tier teams.     

Sodium bicarbonate ingestion increases glycolytic contribution and improves performance during simulated taekwondo combat

Purpose: To investigate the effect of sodium bicarbonate (NaHCO₃) on performance and estimated energy system contribution during simulated taekwondo combat. Methods: Nine taekwondo athletes completed two experimental sessions separated by at least 48?h. Athletes consumed 300?mg/kg body mass of NaHCO₃ or placebo (CaCO₃) 90?min before the combat simulation (three rounds of 2 min separated by 1 min passive recovery), in a double-blind, randomized, repeated-measures crossover design. All simulated combat was filmed to quantify the time spent fighting in each round. Lactate concentration [La^?] and rating of perceived exertion (RPE) were measured before and after each round, whereas heart rate (HR) and the estimated contribution of the oxidative (W_OXI), ATP (adenosine triphosphate)-phosphocreatine (PCr) (W_PCR), and glycolytic (W_{[ La^? ]}) systems were calculated during the combat simulation. Results: [La^?] increased significantly after NaHCO₃ ingestion, when compared with the placebo condition (+14%, P?=?0.04, d?=?3.70). NaHCO₃ ingestion resulted in greater estimated glycolytic energy contribution in the first round when compared with the placebo condition (+31%, P?=?0.01, d?=?3.48). Total attack time was significantly greater after NaHCO₃ when compared with placebo (+13%, P?=?0.05, d?=?1.15). W_OXI, W_PCR, VO₂, HR and RPE were not different between conditions (P?>?0.05). Conclusion: NaHCO₃ ingestion was able to increase the contribution of glycolytic metabolism and, therefore, improve performance during simulated taekwondo combat.     

液压摆式剪板机的运动仿真分析

液压摆式剪板机是锻压行业的重要设备,能否实现预期的剪切动作是保证精度的前提。以往常规的设计主要靠经验和类比同型机器,设计的反复性大,周期长,可靠性差。本文介绍了机床的基本结构和工作原理,详述了利用Pro/ENGINEER软件建立摆式剪板机模型以及进行复杂运动仿真的一些应用技巧和方法,为提高新产品研发效率提供了一种有效的途径。