Application of the principal component waveform analysis to identify improvements in vertical jump performance

The purpose of this study was to determine the effects of training on the force-, velocity-, and displacement-time curves using principal component analysis (PCA) to examine the pre to post intervention changes. Thirty-four trained women basketball players were randomly divided into training and control groups. The training intervention consisted of full squats combined with repeated jumps. The effects of the intervention were analysed before and after the training period of 6 weeks by comparing the principal component scores. The magnitude of differences within-/between-group were calculated and expressed as standardised differences. After the intervention period, clear changes in principal components were observed in the training group compared to the control group. These were related to the execution of a vertical jump with a faster and deeper countermovement that was stopped with greater force. This resulted in greater force from the start of the upward movement phase which was maintained for a longer time. This increase in force throughout a greater range of motion increased the take-off velocity and consequently jumping height.     

Multi-location wideband synthetic aperture imaging for urban sensing applications

The presence of significant multipath propagation and heavy clutter in indoor environments imposes severe limitations on imaging through walls, rendering through-the-wall radar imaging a difficult and complex proposition. It is highly desirable to properly interpret the radar images and determine the contents of the indoor scene with a high level of confidence. Data collected from multiple vantage points around a structure can be used to improve imaging visibility into the indoor scene, which, in turn, enhances indoor target detection and localization. In this paper, we consider multi-location radar imaging. Image fusion techniques for combining synthetic aperture radar images acquired from multiple locations along two sides of an enclosed structure are presented. Supporting results, based on real-data collected in a semi-controlled laboratory environment, are provided which demonstrate the improved performance of the multiple location scheme compared to operation from a single vantage point.     

基于超声测距的可视倒车雷达预警系统设计

针对汽车倒车碰撞事故,设计了以单片机为核心的倒车雷达预警系统,它利用超声波实现无接触测距;利用温度传感器实现温度补偿,使测距精确;利用液晶显示实现距离可视;同时具备语音报警的功能。实验表明,该系统测距范围、测距精度可以满足系统要求,具有较高的应用价值。     

对《钗头凤》的认知解读

认知语言学不断向纵深发展,将认知理论运用到语篇研究中,可以在对语篇进行明确细致分析的基础上,进一步对语言生成与接受背后的认知结构和认知过程的系统进行发掘。本文将使用图形背景理论和隐喻理论来解读《钗头风》所表达的“长歌当哭,情何以堪!爱已成往事,情永存心怀”的爱情主题。     

参数微扰法计算锂离子（L i＋）基态能量

根据参数微扰法理论,选择有效核电荷数为 z*＝3－σ的两个类氢原子的1s、2s和3s态波函数的组合,作为锂离子（Li＋）基态的一级近似波函数。应用微扰法计算了锂离子（Li＋）基态二级近似能量。计算结果表明参数微扰法得到的锂离子（Li＋）基态二级近似能量与实验值的相对误差为0．0291％。     

最低单态和三态硝基甲烷的分子结构与红外光谱的理论研究

文章运用密度泛函方法B3LYP/6-311++G(2d,2P)研究了最低单态和三态硝基甲烷单分子的电子结构和红外频率,绘制了分子在这两种电子态下的红外振动光谱,对它们的红外振动频率进行了理论归属,分析并比较了两种电子态下分子结构和红外振动情况的变化,结果发现三态的硝基甲烷分子的结构要比基态分子结构稍显松散,稳定性下降,分子振动模式中NO2的相关振动有所加强,红外光谱线左移.因此,最低三态分子沿C-N键分裂而致分子分解的可能性较大.     

企业专网机房建设中的几个问题的探讨

企业专网的根本职能是为企业的生产经营提供通讯保障,它在企业生产经营中处于重要地位。文章阐述了在机房设计必须注意的两个问题,即荷载和抗震;分析了电源系统的设计依据及机房接地的问题。     

用VC做探地雷达数据CAD矢量图

本文从探地雷达软件处理后的文件为出发点,经过读取显示,输出参数设置,导出DXF文件,从而实现CAD的矢量成图;文章提出了一种用矢量图来代替位图的方法,克服了探地雷达成果位图失真和不便引用等问题。     

基于CAN总线的Pre—BAS设计与研究

对辅助制动系统的发展现状、构成和工作原理进行了分析,在此基础上,总结国外最新的研究技术,设计了一种基于CAN总线的预制动辅助制动系统（Pre—BAS）。该系统在普通的电子辅助制动系统的基础之上,运用GPS和雷达技术监测路面状况,文章提出了系统的控制方案,并设计了硬件构成和软件流程。     

One hundred marathons in 100 days: Unique biomechanical signature and the evolution of force characteristics and bone density

Background:An extraordinary long-term running performance may benefit from low dynamic loads and a high load-bearing tolerance.An extraordinary runner(age=55 years,height=1.81 m,mass=92 kg) scheduled a marathon a day for 100 consecutive days.His running biomechanics and bone density were investigated to better understand successful long-term running in the master athlete.Methods:Overground running gait analysis and bone densitometry were conducted before the marathon-a-day challenge and near its...