西北民族大学公共体育课武术课程教学现状调查分析

文章运用文献资料、问卷调查、访谈等方法,从西北民族大学公共体育课武术课程的教学现状入手,对教学中所遇到的问题进行调查分析。研究结果显示,公体学生喜爱的武术课教学内容排名前三的是:24式太极拳、五步拳和初级三路长拳,69.57%的学生希望在武术选修课中增加攻防技击的学习内容。教学中存在教学内容单一,教学方法缺乏创新;理论课教学时数偏少,考核方式不够注重学生的整体评价;教学内容的设置与学生选择武术课的动机不符等问题,并针对问题提出相应的发展对策,以期为甘肃省高校武术课程教学的可持续发展提供参考依据。     

太极拳运动对青少年身体健康促进影响的实验研究

本研究主要采用文献资料法、专家访谈法和实验法,探寻太极拳运动对青少年身体健康促进的影响研究,结果显示:太极拳运动有利于提升青少年身体素质,主要表现在提升爆发力、耐力、跳跃素质和柔韧素质上,其中男生的耐力素质和柔韧素质最为明显。建议青少年在从事太极拳运动时应进行合理化动作分组,进行有效的体能素质训练,从而不断提升学生体质健康水平。     

从DMX到Noank:平衡知识共享与版权保护模式的探索

互联网环境下知识共享与版权保护的矛盾使现有版权管理制度陷于困局。哈佛大学法学院贝克曼中心为此提出了三种新版权管理模式DMX、Coop和Noank。为总结和借鉴这三种模式解决问题的思路和方法,本文介绍和分析了这三种模式的产生背景、指导思想、基本构成、运行流程和演进过程,总结了三个模式的创新之处及其对开展知识共享与版权保护平衡研究的启示。结果发现,贝克曼中心把网络空间数字内容自由使用的合法性作为突破点,采取基于网络的合作策略,促成了知识共享与版权保护创新模式的构建。这进一步表明,新机制的建立应该以互联网环境下的数字内容具有公共物品属性这一基本特征为出发点。     

突发事件对三级闭环供应链运行绩效的影响研究——以数量折扣契约为约束

在考虑随机需求基础上,探讨突发事件对以数量折扣契约为约束的三级闭环供应链运行绩效的影响。研究表明:突发事件打破原有闭环供应链协调,供应链的利润流向也发生改变;但当市场需求变化较小时,原有契约参数依然可令供应链保持协调;无论需求变化如何,零售商的市场回收价格却无需改变;最后,调整契约参数可以使闭环供应链具有抗突发事件性。     

运动性心律失常研究现状与前景

运动心脏作为运动员所特有的＂高功能,高储备,大心脏＂一直被认为是运动员良好体能状态的重要保障,但在运动训练监控中我们发现一些运动员或多或少存在某些心脏结构改变和心律失常现象,往往影响运动员的系统训练和竞技水平的提高,常常困扰着运动员和教练员。运动医学研究也显示,在大运动量训练与反复大强度运动后运动心脏细胞与亚细胞的形态结构与功能代谢发生了某些失代偿性改变,引起运动性心肌微损伤,而且,右心房、右心室及内膜下心肌组织是运动心脏对大运动量训练与反复大强度运动的敏感区域,又称易损部位。尽管目前运动性心肌微损伤现象已为人所知,且运动性心律失常发生也与运动性心肌微损伤有关,但其病因、病理及发病机制尚不十分明了,运动员心肌微损伤与运动性心脏意外的发生很难早期诊断、预测和防治。针对优秀运动员潜在心脏隐患的调研也证实优秀运动员存在较高的心律失常风险,且专项训练年限长的运动员更为常见,一些运动员因此而退赛,甚至退役。运动性心律失常已经成为影响运动员体能、健康以及正常训练比赛的重要原因之一,制约了部分优秀运动员竞技水平和比赛成绩的提高。部分退役运动员留下了永久性的心律失常。本文主要针对运动性心律失常的常见类型以及病理变化与发生机制进行了综述与探讨,并对未来研究前景进行了展望,希望开展运动性心律失常电生和分子病理的研究,规避运动场上心血管意外的发生,保障运动员健康、延长运动寿命。     

力竭运动后不同时相大鼠心肌Egr-1蛋白的变化及其在运动性心肌微损伤发生中的作用

目的：探讨力竭运动后不同时相心肌早期生长应答基因Egr-1在蛋白水平的变化特点,为运动性心肌微损伤及心肌功能异常发生机制的阐释提供实验依据。方法：100只健康成年雄性SD大鼠,分为一次力竭游泳运动组、两周反复力竭游泳运动组及安静对照组,分别于力竭运动后即刻、6 h、12 h及24 h取材,应用免疫荧光组化技术和图像分析方法研究大鼠心肌Egr-1蛋白含量的变化。结果：一次力竭运动组大鼠心脏各部位Egr-1蛋白含量即刻组与对照组相比显著性升高（P〈0.05）,24 h组与对照组相比显著性降低（P〈0.05）;反复力竭运动组大鼠心脏各部位Egr-1蛋白含量即刻组与对照组相比显著性升高（P〈0.05）,6 h组、12 h组、24 h组大鼠心脏各部位Egr-1蛋白含量均显著低于对照组（P〈0.05）。结论：不同力竭运动后心脏各部位Egr-1在运动后即刻明显升高,表明心肌细胞Egr-1对力竭运动刺激产生快速应激反应,可能诱导炎性细胞的趋化、聚集以及氧自由基的产生。而心脏各部位Egr-1在力竭运动后24 h内恢复到正常水平,说明力竭运动后心脏Egr-1改变属早期应激反应,且此反应属可复性改变。     

Dancers with patellar tendinopathy exhibit higher vertical and braking ground reaction forces during landing

Dancers are exposed to the effects of repetitive jumping and leaping as are other athletes that tend to develop patellar tendinopathy. Greater vertical ground reaction forces occur during landing from a dance leap than during takeoff and during other common athletic activities. The purposes of this study were: (1) to compare the landing ground reaction force profiles of participants with and without clinically diagnosed patellar tendinopathy, and (2) to determine the strength of the relationship between landing angle, and braking impulse. Eighteen elite pre-professional dancers (12 healthy, 6 with patellar tendinopathy; both groups 50% male) performed sauts de chat for kinetic and kinematic analysis. Dancers with patellar tendinopathy demonstrated greater peak vertical ground reaction force and impulse (36% and 15% greater, respectively). Dancers with patellar tendinopathy demonstrated greater peak braking ground reaction force and impulse (82% and 126% greater, respectively). Landing angle explained 67% of the braking impulse. Dancers with patellar tendinopathy exhibited greater vertical and braking impulses than healthy dancers. Braking impulse was strongly correlated with landing angle. While there was no difference between groups in landing angle, dancers with patellar tendinopathy exhibited greater braking impulse than their non-tendinopathic counterparts, even at similar landing angles.     

PDC and Non-PDC fuzzy control with relaxed stability conditions for contintuous-time multiplicative noised fuzzy systems

This paper presents a relaxed scheme of fuzzy controller design for continuous-time nonlinear stochastic systems that are constructed by the Takagi–Sugeno (T–S) fuzzy models with multiplicative noises. Through Nonquadratic Lyapunov Functions (NQLF) and Non-Parallel Distributed Compensation (Non-PDC) control law, the less conservative Linear Matrix Inequality (LMI) stabilization conditions on solving fuzzy controllers are derived. Furthermore, in order to study the effects of stochastic behaviors on dynamic systems in real environments, the multiplicative noise term is introduced in the consequent part of fuzzy systems. For decreasing the conservatism of the conventional PDC-based fuzzy control, the NQLF stability synthesis approach is developed in this paper to obtain relaxed stability conditions for T–S fuzzy models with multiplicative noises. Finally, some simulation examples are provided to demonstrate the validity and applicability of the proposed fuzzy controller design approach.     

An empirical investigation of factors influencing the adoption of data mining tools

Previous studies explored the adoption of various information technologies. However, there is little empirical research on factors influencing the adoption of data mining tools (DMTs), particularly at an individual level. This study investigates how users perceive and adopt DMTs to broaden practical knowledge for the business intelligence community. First, this study develops a theoretical model based on the Technology Acceptance Model 3, and then examines its perceived usefulness, perceived ease of use, and its ability to explain users’ intentions to use DMTs. The model's determinants include 4 categories: the task-oriented dimension (job relevance, output quality, result demonstrability, response time, and format), control beliefs (computer self-efficacy and perceptions of external control), emotion (computer anxiety), and intrinsic motivation (computer playfulness). This study also surveys the moderating effect of experience and output quality on the determinants of DMT adoption and use. An empirical study involving 206 DMT users was conducted to evaluate the model using structural equation modeling. Results demonstrate that the proposed model explains 58% of the variance. The findings of this study have interesting implications with respect to DMT adoption, both for researchers and practitioners.     

User-satisfaction based bandwidth allocation for transmission of multiple sources of human perceptual data

In recent years, more and more point-to-point communication systems involve simultaneous transmission of multiple sources of human perceptual data over a single communication medium. For example, in a teleoperation system or a telerobotic system, streams of video, audio, and haptic data need to be sent from a field place to a remote human operator. Each type of data demands a certain range of transmission rate. This creates conflicts among these data when the available bandwidth is limited.In this paper we study the bandwidth allocation for multiple sources of human perceptual data transmitted over a rate-limited communication channel. We aim to maximize the overall user satisfaction in the data transmission, and formulate an optimization problem for the bandwidth allocation. Using either the logarithmic or exponential form of human perceptual satisfaction function, we are able to derive closed-form solutions for the optimization problem. We show that the optimal bandwidth allocation for each type of data is piecewise linear with respect to the total available bandwidth.