地面运动强度度量参数与双线性单自由度系统变形需求的相关性研究

研究了用峰值地面运动加速度(APG)、峰值地面运动速度(VPG)、峰值地面运动位移(DPG)、谱加速度AS(T1)(在结构基阶周期的谱加速度值)和VPG/APG作为地面运动强度度量参数(I M)与双线性单自由度(SDOF)结构系统的变形需求之间的相互关系,并用相关系数Ρ表示.通过非线性动力分析得到的结果表明,谱加速度AS(T1)和VPG与双线性SDOF结构系统的变形需求有着很好的相关性.因而,进一步研究了分别以谱加速度AS(T1)和VPG作为I M时,对3个周期(T=0.3S、1.0S和3.0S)的SDOF结构系统的变形需求估计时的有效性(这里的有效性是指在给定I M下结构响应的离散性).

以系统可靠性为目标的系统运动动力、表现与度量研究

为研究系统运动的动力、表现和度量,提出系统运动空间和系统映射论,并以系统可靠性作为实现平台。借助信息生态思想作为方法论、因素空间理论作为智能分析的数学基础、空间故障树理论作为研究系统可靠性的平台,建立了一种新的研究框架。结果表明,系统运动的动力是因素及其变化,表象是数据及其变化。进而为度量系统运动建立了系统运动空间模型,借助空间故障树的方法即可实现度量。同时认为人的智慧活动是系统运动过程中数据信息到因素的映射;而自然系统是所有因素到所有数据的映射,前者只能趋近而无法达到后者的高度和水平。

地面运动强度度量参数的有效性研究

概率地震需求分析的目标是估计结构在不同地面运动强度水平下的响应,结构响应的不确定性对采用的地面运动强度度量参数有着很强的依赖.因而,需要比较所采用的地面运动强度度量参数的有效性.这里推荐了一个新的采用向量地面运动强度度量参数来估计结构需求的方法,并把这个地面运动强度度量参数应用于一些不同周期和不同强度折减系数的单自由度结构系统.统计结果表明,推荐的地面运动强度度量参数可以有效地减小估计单自由度结构系统最大变形延性需求时的离散性,而且减少了计算分析工作量.

基于移动预测模型的ad hoc网络稳定链路度量

提出了一种基于移动预测模型的稳定链路度量算法,定义了稳定邻居度量和本地运动度量2种测度。根据这2种测度,移动预测模型利用LZ78算法对本地节点与其邻居的稳定性概率进行预测,从而找到其最稳定邻居,为选择稳定路由提供依据。仿真结果表明此算法明显优于直方图算法及最小ID算法,所选链路的稳定性能显著提高。

动态特征和静态特征自适应融合的目标跟踪算法

由于大多数目标跟踪算法只采用单一静态特征或单一动态特征对目标建模,但静态特征模型不能描述目标的动态特性,并且很难适应场景复杂、快速移动和旋转等问题;而传统运动光流能够描述局部动态特性,却存在孔径问题.提出一种自适应融合动态特征和静态特征的跟踪方法:通过双向光流预测和误差度量自适应提取动态特征,并提取候选目标区域的静态特征,然后构造融合权重函数有效地融合动态特征和静态特征并以此构造协方差矩阵估计误差椭圆,准确描述目标尺度和方向,实现对目标精确表示;通过on-line参数更新机制对权重分配参数进行更新,实现动态特征和静态特征分配的自适应调节,能够适应目标运动速度的变化和场景变化.实验结果表明,在背景复杂的情况下,当目标快速移动或旋转时,与其他相关算法相比,该算法能够获得更好的跟踪效果.

对200m项目奥运游泳选手的分析研究

对1988年汉城奥运会游泳项目录像分析研究获得每个运动员的划频(SR)和划幅(SL)数据。本文把200m项目运动员的SR与SL和运动员的个体特征度量(身高、年龄)及最后成绩结合起来。然后进行统计分析,以确定各度量间的相关性以及与最后成绩的相关系数。同时还研究了男女运动员在执行动作上的差异性。发现划幅与最后成绩间存在高度相关。身高与最后成绩间也有高度相关。平均而言,男子比女子划频慢,速度快。后一发现或许是由于男子较长的划幅和较高的身材所致。

A NOVEL METHOD FOR CALCULATING VERTICAL VELOCITY:A RELATIONSHIP BETWEEN HORIZONTAL VORTICITY AND VERTICAL MOVEMENT

The present work provides a novel method for calculating vertical velocity based on continuity equations in a pressure coordinate system.The method overcomes the disadvantage of accumulation of calculating errors of horizontal divergence in current kinematics methods during the integration for calculating vertical velocity,and consequently avoids its subsequent correction.In addition,through modifications of the continuity equations,it shows that the vorticity of the vertical shear vector(VVSV) is proportional to-ω,the vertical velocity in p coordinates.Furthermore,if the change of ω in the horizontal direction is neglected,the vorticity of the horizontal vorticity vector is proportional to-ω.When ω is under a fluctuating state in the vertical direction,the updraft occurs when the vector of horizontal vorticity rotates counterclockwise;the downdraft occurs when rotating clockwise.The validation result indicates that the present method is generally better than the vertical velocity calculated by the ω equation using the wet Q-vector divergence as a forcing term,and the vertical velocity calculated by utilizing the kinematics method is followed by the O'Brien method for correction.The plus-minus sign of the vertical velocity obtained with this method is not correlated with the intensity of d BZ,but the absolute error increases when d BZ is >=40.This method demonstrates that it is a good reflection of the direction of the vertical velocity.

Sleep quality improved following a single session of moderate-intensity aerobic exercise in older women:Results from a pilot study

Background： Poor sleep quality is associated with adverse effects on health outcomes. It is not clear whether exercise can improve sleep quality and whether intensity of exercise affects any of the effects. Methods： Fifteen healthy, non-obese （body mass index = 24.4 ± 2.1 kg/m^2, mean 4- SD）, sedentary （〈20 min of exercise on no more than 3 times/week） older women （66.1 ± 3.9 years） volunteered for the study. Peak oxygen consumption （VO2peak） was evaluated using a graded exercise test on a treadmill with a metabolic cart. Following a 7-day baseline period, each participant completed two exercise sessions （separated by 1 week） with equal caloric expenditure, but at different intensities （60% and 45% VO2peak, sequence randomized） between 9：00 and 11：00 am. A wrist ActiGraph monitor was used to assess sleep at baseline and two nights following each exercise session. Results： The average duration of the exercise was 54 and 72 rain, respectively at 60% （moderate-intensity） and 45% VO2peak （light-intensity）. Wake time after sleep onset was significantly shorter （p = 0.016）, the number of awakenings was less （p = 0.046）, and total activity counts were lower （p = 0.05） after the moderate-intensity exercise compared to baseline no-exercise condition. Conclusion： Our data showed that a single moderate-intensity aerobic exercise session improved sleep quality in older women.

Weigh in Motion Based on Parameters Optimization

Dynamic tire forces are the main factor affecting the measurement accuracy of the axle weight of moving vehicle.This paper presents a novel method to reduce the influence of the dynamic tire forces on the weighing accuracy.On the basis of analyzing the characteristic of the dynamic tire forces,the objective optimization equation is constructed.The optimization algorithm is presented to get the optimal estimations of the objective parameters.According to the estimations of the parameters,the dynamic tire forces are separated from the axle weigh signal.The results of simulation and field experiments prove the effectiveness of the proposed method.

Kinematic Viscosity and Shear Stress of Used Engine Oil

The goal of this paper describes kinematic viscosity and shear stress of two used engine oils, which have been taken from two different passenger cars. Kinematic viscosity and shear stress are two of the most important physical behaviours of fluids, especially lubricating fluids. In this paper the authors have focused on engine oil. Knowledge of these properties of engine oil is very important due to its lifetime. The experiments have been done using digital rotary rheometer Anton Paar DV-3 P with use of TR8 spindle and special adapter for a small amount of sample （20 mL）. Two different engine oils have been observed--first from passenger car Renault Scenic with petrol engine （engine capacity 1.6 dm3） and the second from passenger car Skoda Roomster with diesel engine （engine capacity 1.4 dm3）. Castrol Magnatec 10W-40 engine oil has been taken from Renault car and Shell Helix Ultra Extra 5W-30 engine oil has been taken from ~koda car. Service interval of change oil has been set to 15,000 km and samples of used engine oils have been taken after 1,500 km. Only first samples of used engine oils have been taken after raid of 20 km. All samples of used engine oils have been compared with new （unused） engine oils same specification. The measured values of kinematic viscosity and shear stress have been modeled using linear function. The coefficients of correlation R have been achieved high values （0.88-0.96）. The obtained models can be used to prediction of engine oil flow behaviour.

Research of Dynamic Variations in the Gravitational Field of Forthcoming Volcano Eruption

There is expounded the theory of＂gravitational＂ wave propagation from the volcano crater （magma） under changing density of magma mass inside the volcano. It was revealed that while the abruptly accelerated magma movement during starting period began eruption, the registered ＂gravitational＂ waves were being emitted and were propagating with the velocity greater than that of sound and seismic waves velocity. Alteration of ＂gravitational＂ waves velocity under the magma movement can be additional feature in prognosis of the start time of volcano eruption. The considered method might be effective when making up prognoses of underwater volcano eruption.

Identifying Similar Operation Scenes for Busy Area Sector Dynamic Management

Air traffic controllers face challenging initiatives due to uncertainty in air traffic.One way to support their initiatives is to identify similar operation scenes.Based on the operation characteristics of typical busy area control airspace,an complexity measurement indicator system is established.We find that operation in area sector is characterized by aggregation and continuity,and that dimensionality and information redundancy reduction are feasible for dynamic operation data base on principle components.Using principle components,discrete features and time series features are constructed.Based on Gaussian kernel function,Euclidean distance and dynamic time warping(DTW)are used to measure the similarity of the features.Then the matrices of similarity are input in Spectral Clustering.The clustering results show that similar scenes of trend are not ideal and similar scenes of modes are good base on the indicator system.Finally,actual vertical operation decisions for area sector and results of identification are compared,which are visualized by metric multidimensional scaling(MDS)plots.We find that identification results can well reflect the operation at peak hours,but controllers make different decisions under the similar conditions before dawn.The compliance rate of busy operation mode and division decisions at peak hours is 96.7%.The results also show subjectivity of actual operation and objectivity of identification.In most scenes,we observe that similar air traffic activities provide regularity for initiatives,validating the potential of this approach for initiatives and other artificial intelligence support.

Optimal measurement configurations for kinematic calibration of six-DOF serial robot

An optimal measurement pose number searching method was designed to improve the pose selection method.Several optimal robot measurement configurations were added to an initial pre-selected optimal configuration set to establish a new configuration set for robot calibration one by one.The root mean squares (RMS) of the errors of each end-effector poses after being calibrated by these configuration sets were calculated.The optimal number of the configuration set corresponding to the least RMS of pose error was then obtained.Calibration based on those poses selected by this algorithm can get higher end-effector accuracy,meanwhile consumes less time.An optimal pose set including optimal 25 measurement configurations is found during the simulation.Tracking errors after calibration by using these poses are 1.54,1.61 and 0.86 mm,and better than those before calibration which are 7.79,7.62 and 8.29 mm,even better than those calibrated by the random method which are 2.22,2.35 and 1.69 mm in directions X,Y and Z,respectively.

Evaluation of Skills in Swing Technique in Classical Japanese Swordsmanship in laido Using Sensors

In this study, we analyzed the swing motions of more experienced practitioner and new practitioner of iaido players by using tri-axial acceleration sensor and gyro sensor. Iaido is a modern Japanese martial art/sport. In this way, the acceleration and gyro sensor measurement enabled detailed motion information at the installation points to be displayed in a short time, thus making it possible to easily extract the objective problems. Although it was not possible to confirm by the acceleration and angular velocity measurements the detailed motion of the entire body as obtained in the 2D motion analysis with a high-speed camera, it was confirmed that the acceleration and gyro sensor is an evaluation means that can be installed easily and can provide the exercise information in a short time as an objective index.

Research for the Relationships between Body Acceleration and Energy Expenditure

During our research,It has been found that body acceleration has strong relationships with the human energy expenditure.This paper discusses the methods to assess physical activity and concludes that for accurate assessment of physical activity under free living conditions the recently introduced accelerometer looks most promising.We developed a new computerized machine to assess the body activity and energy expenditure.Test datas of the treadmill experiment,respiration experiment and 5-kilometer-running experiment have been archieved,we found that body acceration integrals with time has linear relations with body energy expenture.

A complexity-scalable software-based MPEG-2 video encoder

With the development of general-purpose processors (GPP) and video signal processing algorithms, it is possible to implement a software-based real-time video encoder on GPP, and its low cost and easy upgrade attract developers' interests to transfer video encoding from specialized hardware to more flexible software. In this paper, the encoding structure is set up first to support complexity scalability; then a lot of high performance algorithms are used on the key time-consuming modules in coding process; finally, at programming level, processor characteristics are considered to improve data access efficiency and processing parallelism. Other programming methods such as lookup table are adopted to reduce the computational complexity. Simulation results showed that these ideas could not only improve the global performance of video coding, but also provide great flexibility in complexity regulation.

Accurate vision measurement for kinematic parameters of satellite separation tests

The accurate measurement of kinematic parameters in satellite separation tests has great significance in evaluating separation performance. A novel study is made on the measuring accuracy of monocular and binocular, which are the two main vision measurement methods used for kinematic parameters. As satellite separation process is transient and high-dynamic, it will bring more extraction errors to the binocular. Based on the design approach of intersection measure and variance ratio, the monocular method reflects higher precision, simpler structure and easier calibration for level satellite separation. In ground separation tests, a high-speed monocular system is developed to gain and analyze twelve kinematic parameters of a small satellite. Research shows that this monocular method can be widely applied for its high precision, with position accuracy of 0.5 mm, speed accuracy of 5 mm/s, and angular velocity accuracy of 1 (°)/s.

Gray Synthetic Evaluation on Moisture Comfort of Sportswear Fabrics under the Condition of Heavy Sweating

Moisture and water transfer under the condition of heavy sweating are analyzed. Four different experiments are made to test moisture resistance, water-keep, wicking effect and drying ability of samples. Then gray analysis method is introduced to evaluate the comprehensive comfort of these fabrics. Result shows chemical fiber with high moisture transfer performance has advantage in water transfer and diffusion, which is suitable for human under the condition of heavy sweating. Though natural fiber can absorb moisture well, it cannot transfer fluid sweat. Therefore natural fiber fabrics such as cotton, wool are unsuitable to make functional sportswear.

Related turbulent momentum and passive scalar transfer in a turbulent channel flow

Direct numerical simulation was carried out to investigate the correlation between the momentum and passive scalar transfer in a turbulent channel flow with Re_(τ)=u_(τ)δ/ν=180 and Pr=0.71,where u_(τ)is the friction velocity,δis the channel half width,andνis the kinematic viscosity.The one-point and two-point energy transfer and the corresponding scalar transfer are of particular interest.There is a significant positive correlation between the one-point energy and scalar transfer,particularly near the wall,and the correlation between the two production terms is always larger than that between the other terms.By resorting to the Karman-Howarth-Monin-Hill equation and the scale-by-scale scalar transfer budget equation,we explored the two-point energy and scalar transfer at two different vertical locations(i.e.,one location close to the wall y^(+)=10 and the other location slightly away from the wall y^(+)=60).An inverse interscale transfer phenomenon of the energy and scalar is observed in the spanwise direction at y^(+)=10,which is caused by the corresponding streak stretching,whereas along the streamwise and the vertical directions a forward interscale energy and scalar transfer phenomenon is observed.The physical mechanisms(e.g.,production,dissipation,and viscous diffusion terms)contributing to the two-point energy transfer closely resemble those in the two-point scalar transfer.The intrinsic correlation between both the two-point energy and scalar transfer can find its roots in the similarity between the momentum and scalar streaks.

Experimental Investigation of Dimensionless Velocity and Shearing Stress in Boundary Layer Flow on Continuous Moving Surface in Power Law Fluids

An analysis is carried out to study the steady flow characteristics from a continuous flat surface moving in a parallel free stream of non-Newtonian power law fluid. The constitutive equations of the fluid are transformed into dimensionless ones. The velocity field is measured by Particle Image Velocimetry. Experimental results are obtained for the distribution of velocity. The influence of wall velocity ratio parameter on boundary layer flow field is observed in the experiment. Dimensionless velocity distribution and shearing stress distribution are obtained by post-processing experimental results. The effects of various physical parameters like velocity ratio parameter and similarity variable on various momentum transfer characteristics are discussed in detail and shown graphically. It is indicated that dimensionless velocity increases with velocity ratio parameter and similarity variable, and that dimensionless shearing stress decreases with velocity ratio parameter and similarity variable.