Real-time prediction of the motion tendency of human lower limbs during gait

Aiming at the problem of hysteresis in the human motion intention recognition algorithm based on kinematic sensors, a real-time prediction method about human lower limb motion tendency is proposed. It could be used to control exoskeleton robots, intelligent prosthes and other equipments in advance to eliminate the hysteresis of equipment movement. Firstly, the angle signals of ankle, knee and hip are segmented by the extreme points. Secondly, the multi-dimensional temporal association rules algorithm is used to analyze the angle signals to find out the relationships between signal patterns in adjacent time segments. Finally, the signal patterns at the next moment are predicted through the association rules algorithm, so as to predict the motion tendency of human lower limbs. Experimental results show that the proposed scheme achieves an average prediction accuracy of 78.3% for each signal segment, and can predict the subsequent motion of human lower limbs in average 92.24 ms.     

Point-tracked quantitative analysis of left ventricular surface motion from 3-D image sequences

We propose and validate the hypothesis that we can use differential shape properties of the myocardial surfaces to recover dense field motion from standard three-dimensional (3-D) image sequences (MRI and CT). Quantitative measures of left ventricular regional function can be further inferred from the point correspondence maps. The noninvasive, algorithm-derived results are validated on two levels. First, the motion trajectories are compared to those of implanted imaging-opaque markers of a canine model in two imaging modalities, where subpixel accuracy is achieved. Second, the validity of using motion parameters (path length and thickness changes) for detecting myocardial injury area is tested by comparing algorithms derived results to postmortem analysis TTC staining of myocardial tissue, where the achieved Pearson product-moment correlation value is 0.968.     

A quantitative analysis of anonymous communications

This paper quantitatively analyzes anonymous communication systems (ACS) with regard to anonymity properties. Various ACS have been designed & implemented. However, there are few formal & quantitative analyzes on how these systems perform. System developers argue the security goals which their systems can achieve. Such results are vague & not persuasive. This paper uses a probabilistic method to investigate the anonymity behavior of ACS. In particular, this paper studies the probability that the true identity of a sender can be discovered in an ACS, given that some nodes have been compromised. It is through this analysis that design guidelines can be identified for systems aimed at providing communication anonymity. For example, contrary to what one would intuitively expect, these analytic results show that the probability that the true identity of a sender can be discovered might not always decrease as the length of communication path increases.     

三维人体运动的计算机辅助分析在体育中的应用

近年来,计算机技术在竞技体育中应用的范围越来越广。运动员在训练中采用先进的科学技术可以提高其训练的效果。本文阐述了三维人体运动的计算机辅助分析在体育中的应用,包括三维人体运动的定义,分析了基于骨骼蒙皮法构建运动员模型,最后阐述了运动数据的预处理、提取和分析。     

三维人体运动的计算机辅助分析在体育中的应用

近年来,计算机技术在竞技体育中应用的范围越来越广。运动员在训练中采用先进的科学技术可以提高其训练的效果。本文阐述了三维人体运动的计算机辅助分析在体育中的应用,包括三维人体运动的定义,分析了基于骨骼蒙皮法构建运动员模型,最后阐述了运动数据的预处理、提取和分析。     

Design and motion planning of hydraulically driven leg for maximum height jumping

This paper presents an optimized design and motion planning method of a hydraulically driven leg for jumping. The knee joint range was enlarged, and the desired torque profile was achieved using a four-bar linkage. The dynamics of the robot were considered during the motion planning, and the optimal trajectory was obtained by linear programming. Simulations and experiments showed that the leg could jump 1 m under a load of 50 kg.     

Noninvasive measurement of compliance of human leg arteries

Electrical impedance plethysmography has been evaluated for early detection of peripheral atherosclerosis. A pressure cuff was wrapped around the lower leg and the cuff pressure increased. Two circumferential electrodes glued in the middle of the cuff recorded the impedance pulse, from which the arterial pulse volume was calculated. The ratio of maximal arterial volume change to the pulse pressure was determined as a measure of maximal compliance Cp. Based on the data from 118 human subjects, Cp was found to correlate well with known cardiovascular risk factors. For example, Cp decreased on the average from 3.08 to 1.92 microL.mm Hg-1.cm-1 (1 microL.mm Hg-1.cm-1 = 7.5 x 10(-10) m4.N-1) in groups of subjects of increasing age from 22 to 70 years. Subjects on a regular exercise program had an average value of 3.86, while those with proven peripheral vascular disease had a value of 0.70. In a related pathologic validation study on 15 monkeys fed a cholesterol-control diet a good correlation was found between the limb peak compliance and morphometric data obtained from iliac and carotid arteries.     

一种基于运动分析的行人异常行为检测

提出了一种基于运动分析的行为检测方法,用于行人异常行为的检测.利用HSV色彩空间变换法抑制阴影,利用三帧法建立初始化背景模型.将所提取的连续三帧图像的背景像素进行填充融合以实现背景图像的重构,进而更新背景图像,最终完成背景图像的建立.将大津法(Otsu)和背景差分法进行融合以自适应检测前景目标,将目标区域的质心差值、矩...     

简易量化分析方法在网优策略中的应用

作为全球少数几个超大本地网之一,近年来,上海地区移动通信网络情况日益复杂,在话音业务中的客户感知和运营商网络指标之间存在着一定程度的差异.为了改善客户最终体验,需要优化网络综合质量.在对网络优化目标原则进行了研究之后,提出了一种简易的网优策略量化分析方法,定义了一系列场景采用量化算法对比分析,寻找在安全、成本、容量上的...     

A study of the range of motion of human fingers with application toanthropomorphic designs

The multifingered human hand serves as a model for anthropomorphic manipulators and prosthetic devices. In order to better guide the design of these devices, a study of the range of motion of human fingers is presented. The role of tendons in the actions of human fingers is modeled and results of experimental studies on the range of motion of fingers in normal humans are presented. Further study of disabled hands illustrates constraints imposed by deficient tendon mechanisms. The basic investigations of normal and disabled hands guide the design of tendon-based actuators for mechanized fingers. The design of a prototype finger actuated by a shape-memory alloy material serving as a tendon is discussed     

A quantitative analysis of the stress relaxation effect ofthermoplastics in multilayer substrates

All plastics can be divided into two groups called thermoplastics and thermosets, and each group exhibits very different behaviors. Unlike thermosets, thermoplastics are empirically known by the viscoelastic behavior of the thermoplastic layers; the stress generated by building subsequent layers can be significantly relieved in a multilayer structure. In this study, we quantitatively investigated the stress relaxation effect of thermoplastics in lamination-based multilayer substrates. As an increasing number of layers were laminated using either thermoplastic or thermoset adhesives, the maximum bow values were measured layer-by-layer using a laser profilometry during thermal cycling. When analyzed through an analytical model, the measured thermal behavior of thermoplastics exhibited as much as 70% stress relaxation in the multilayer structures, and highly contrasted with that of thermoset adhesives. The result provides an important design guideline that thermoplastics can be used as a stress relaxation layer in lamination-based multilayer substrates     

A tool for the quantitative spatial analysis of complex cellular systems.

Spatial events largely determine the biology of cells, tissues, and organs. In this paper, we present a tool for the quantitative spatial analysis of heterogeneous cell populations, and we show experimental validation of this tool using both artificial and real (mammary gland tissue) data, in two and three dimensions. We present the refined relative neighborhood graph as a means to establish neighborhood between cells in an image while modeling the topology of the tissue. Then, we introduce the M function as a method to quantitatively evaluate the existence of spatial patterns within one cell population or the relationship between the spatial distributions of multiple cell populations. Finally, we show a number of examples that demonstrate the feasibility of our approach.     

一种两阶段变量选择的LIBS定量分析方法

使用机器学习方法结合激光诱导击穿光谱(Laser Induced Breakdown Spectroscopy,LIBS)进行定量分析,变量选择的结果直接影响最终的定标模型.现有的变量选择方法多存在需要先验知识、计算量庞大等问题,因此提出一种两阶段变量选择方法.第一阶段为排序阶段,以皮尔逊相关系数r为排序准则快速排除与...     

In situ quantitative analysis of etching process of human teeth by atomic force microscopy

Etching is one of the most fundamental steps in the restoration of teeth by adhesion of composite resin in dental clinics. Atomic force microscope (AFM) was used for the in situ observation of the etching process of human enamel, dentin and synthetic hydroxyapatite in the three different acid agents, 2% phosphoric acid, 10% citric acid and 10% polyacrylic acid. To measure the absolute depth from the initial level before etching and to correlate the surface height between the changing AFM images obtained, the depth profiles were recorded with etching time by carrying out the line scan consecutively at the representative place of the observed area. These chronological series of depth profiles enabled us to perform quantitative analysis of etched amount in addition to the surface roughness obtained from relative depth profile within one image. The course of etching process from the dissolution of smear layer, appearance of enamel prizms or dentinal tubules to progress of demineralization could clearly be observed. The depth profile, surface roughness, etching amount, etching rate and smear layer thickness could then be evaluated. The different etching characteristics of three acid agents and the effect of surface roughness produced by different mechanical prepolish were compared and discussed.     

A multidimensional wave digital filter bank for video-based motion analysis

Multidimensional wave digital filters (MDWDF) exhibit the same desirable properties as 1D WDFs, most notably including passivity and therefore guaranteed stability as well as high robustness. A possible application for such MDWDFs may be found in motion analysis of image sequences by means of filters with fan-shaped transfer functions, where content with specific movement information can be extracted. For that matter, a parallel filter bank is needed to differentiate object motion into separate classes. In this paper, a new specialized MDWDF fan filter structure is introduced, possessing both reduced computational complexity and memory requirements compared to existing approaches. Additionally, part of the processing can be shared among all bands, further increasing efficiency.     

A TENSOR ANALYSIS METHOD FOR ESTIMATING 3-D MOTION PARAMETERS

By using the center projection image sequence to estimate 3-D motion parameters,one needs to know the corresponding relationship between the feature of motion object in spaceand the projection coordinate on image plane.In order to avoid using the relationship of featurecorrespondence,the tensor analysis method in the affine transformation system is presented,andthe simulation data of experimental results are given.     

A quantitative analysis of SNR in the short-time Fourier transformdomain for multicomponent signals

A quantitative analysis is given for the signal-to-noise ratio (SNR) in the short-time Fourier transform domain for multicomponent signals in additive white noise. It is shown that the SNR is increased on the order of O(N/K), where K is the number of components of a signal, N/T is the sampling rate, and T is the window size. The SNR increase rate is optimal for given K. For this result, the SNR definition is generalized, which is suitable for signals not only in the time domain but also in other domains. This theory is illustrated by one numerical example     

High-level behavior of power rectifiers: A quantitative analysis of the forward voltage drop

In forward biased power rectifiers, quasi-neutrality holds in all regions of the device. As a consequence, numerical analysis of the behavior of the devices can be carried out without involving the treatment of Poisson's equation. This allows fast and accurate computation of the forwardJ(V)characteristic. Taking into account the physical mechanisms appearing at high concentration levels of impurities and carriers, the numerical results obtained agree with the experimental ones. This is shown for a series of devices covering a wide range of technological parameters such as the width of the semiconductor layers, the conditions of gold diffusion, etc.