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1.
It is still controversial whether or not to resurface patella during primary total knee arthroplasty (TKA). One of the reasons may be insensitive measurement tools. We conducted a randomized controlled study to compare kinematic and kinetic parameters of resurfacing and nonresurfacing patella with the Vicon gait analysis system. The results show that patient post-operative gait of the two groups improved compared to pre-operative gait. Part of gait parameters, knee flexion at heel-strike, double limb support time and maximum adduction angle appeared to be statistically difference in 3 months, but 12 months later, the gait parameters of the two groups had no significant difference. Therefore, it seems that the final function of knee after TKA is not related whether or not to resurface patella.  相似文献   

2.
Cerebral palsy (CP) is a group of permanent movement disorders that appear in early childhood. The electromyography (EMG) signal analysis and the gait analysis are two most commonly used methods in the clinic. In this paper, a cyclostationary model of the EMG signal is proposed. The model can combine the aforementioned two methods. The EMG signal acquired during the gait cycles is assumed to be cyclostationary due to the physiological characteristics of the EMG signal production. Then, the spectral correlation density is used to analyze the cyclic frequency (corresponding to the gait cycles) and spectral frequency (the frequency of EMG signal) in a waterfall representation of the two kinds of frequencies. The experiments show that the asymptomatic (normal) subjects and symptomatic subjects (with CP) can be distinguished from the spectral correlation density in a range of cyclic frequencies.  相似文献   

3.
两足机器人步态综合研究进展   总被引:7,自引:0,他引:7  
把两足机器人步态综合方法分为参考轨迹法和自然动力学法两大技术流派.根据参考轨迹获得方法的不同,参考轨迹法又分为步行数据法、中枢模式发生器法和动力学模型法.自然动力学法也可分为被动动力学法和虚拟模型法.在总结两大流派研究进展的基础上,分析了它们各自的优势和不足,指出了今后工作的重点,即参考轨迹法需要提高步行效率和轨迹的生成速度,而自然动力学法需要增加功能.最后分析了强制学习技术在步态综合中应用的适应性和多自由度造成的组合爆炸问题.  相似文献   

4.
In this paper, a gait control scheme is presented for planar quadruped robots based on a biologic concept, namely central pattern generator (CPG). A CPG is modeled as a group of the coupled nonlinear oscillators with an interaction weighting matrix which determines the gait patterns. The CPG model, mapping functions and a proportional-differential (PD) joint controller compose the basic gait generator. By using the duty factor of gait patterns as a tonic signal, the activity of the CPG model can be modulated, and as a result, a smooth transition between different gait patterns is achieved. Moreover, by tuning the parameters of the CPG model and mapping functions, the proposed basic gait generator can realize adaptive workspace trajectories for the robot to suit different terrains. Simulation results illustrate and validate the effectiveness of the proposed gait controllers.  相似文献   

5.
Human performs bipedal gait with synchronized arm swing. Apart from the observation that arm movement during gait is the outcome of a mechanical and energetic optimization, the synergetic upper and lower limb movement during gait is a neutrally coordinated motor output, that is, the interlimb movement is neutrally coupled. Patients with injuries to the central nervous system demonstrate the interlimb neural coupling. Researches on central pattern generator and the reflex studies reveal that the interlimb neural coupling is a quadrupedal heritage. Based on the theory of the interlimb neural coupling, both the upper and lower limbs should be practiced synchronously during regular gait training to promote walking rehabilitation for patients with gait disorders. Frther development of a gait robotic system with synchronized arm swing is required to test the clinical application of the neural coupling in gait restoration.  相似文献   

6.
Along with higher and higher integration of intellectual properties (IPs) on a single chip, traditional bus-based system-on-chips (SoC) meets several design difficulties (such as low scalability, high power consumption, packet latency and clock tree problem). As a promising solution, network-on-chips (NoC) has been proposed and widely studied. In this work, a novel algorithm for NoC topology synthesis, which is decomposing and cluster refinement (DCR) algorithm, has been proposed to minimize the total power consumption of application-specific NoC. This algorithm is composed of two stages: decomposing with cluster generation, and cluster refinement. For partitioning and cluster generation, an initial low-power solution for NoC topology is generated. For cluster refinement, the clustering is optimized by performing floorplan to further reduce power consumption. Meanwhile, a good tradeoff between power consumption and CPU time can be achieved. Experimental results show that the proposed method outperforms the existing work.  相似文献   

7.
采用基于机器视觉的三角测距原理和光取断面法,开发出将廓形上的激光点进行空间坐标转换的算法,消除了已有方法中借助标定板计算所带来的误差和操作的复杂性,提高了钢轨动态测量的精度和效率.开发了非接触式钢轨检测装置.通过对60轨打磨后轨廓的测量结果与标准廓形的分析比对,验证了开发系统的精度和性能.  相似文献   

8.
铁路平交道口控制系统是一种典型的安全苛求系统,为提高铁路平交道口的安全性,提出一个能适应双线双向接车的自动控制系统.首先,分析现有铁路平交道口的作业流程,利用新的控制系统解决现有系统中常见的三个问题,即出清检查、制动距离限制、连续接车中防护门短时间开放问题;其次,基于Event-B语言以及精化策略对设计的自动控制系统建立形式化模型;最后,检查证明义务以验证需求属性是否被满足,并应用动画器Animation展示系统功能的正确性.结果显示:相比传统的道口管理系统,本文提出的自动控制系统增加了双线连续接车功能,且使用形式化建模和验证,避免系统设计中存在的二义性,对平交道口安全管理有一定的参考意义.  相似文献   

9.
为克服非稳定交通流状态下短时交通流预测精度不高、过分依赖大样本历史数据的缺陷,提出一种改进小波包分析和长短时记忆神经网络组合(IWPA-LSTM)的短时交通流预测方法. 利用功率谱细化的思想改进小波包分析算法对小样本交通流时间序列进行多尺度分解和单支重构. 对低频序列和高频序列进行相空间重构,完成长短时记忆模型的逐层构建,实现本地保存并根据预测精度进行自适应更新,将重构的子序列输入模型训练和预测. 将各子序列的预测值叠加输出IWPA-LSTM最终预测值. 实验结果表明,提出的IWPA-LSTM模型在小样本情况下的预测精度优于经典深度学习模型,具有较强的实用性.  相似文献   

10.
A new passive wheel type of biped ice-skating robot(BISR)which was able to imitate human skating motion was developed. Firstly, the characteristics of two types of human skating gait were introduced; secondly, after simplifying the kinematical model, the BISR's motion principle was presented; then the construction and control system of BISR were proposed; at last, the skating experiment of the BISR in a symmetric gait mode was conducted and some conclusions were drawn.  相似文献   

11.
GB13094—2007《客车结构安全要求》是对同名标准GB13094—1997的修订,属强制性国家标准。修订后的标准.提高和细化了原有的结构要求,增加了更加安全和更人性化的规定,有利于促进我国客车技术水平的提高。  相似文献   

12.
GB13094—2007《客车结构安全要求》是对同名标准GB13094—1997的修订,属强制性国家标准。修订后的标准,提高和细化了原有的结构要求,增加了更加安全和更人性化的规定,有利于促进我国客车技术水平的提高。  相似文献   

13.
随着城市化进程快速推进,大城市建成区支路规划缺位、管理能力不足及断面设计精细化程度不高等问题日益凸显,有必要加强支路网系统性解决方案研究。鉴于此,从支路发展的自身特点出发,归纳总结支路网基本功能、要求和价值意义,明确了支路网在城市发展过程中所扮演的角色和定位。在此基础上,结合大城市建成区城市与交通发展特点,以佛山市禅城区为例,通过充分认识禅城区地方发展诉求和支路网系统存在的问题,提出规划引领、强化落实、优化布局、制度创新、功能导向和精细化设计等六大支路网改善与提升策略,在形成禅城区支路网系统化解决方案的同时,也可为其他大城市建成区支路网发展提供参考。  相似文献   

14.
This paper proposed a novel model-based feature representation method to characterize human walking properties for individual recognition by gait. First, a new spatial point reconstruction approach is proposed to recover the coordinates of 3D points from 2D images by the related coordinate conversion factor (CCF). The images are captured by a monocular camera. Second, the human body is represented by a connected three-stick model. Then the parameters of the body model are recovered by the method of projective geometry using the related CCF. Finally, the gait feature composed of those parameters is defined, and it is proved by experiments that those features can partially avoid the influence of viewing angles between the optical axis of the camera and walking direction of the subject. Foundation item: the National Natural Science Foundation of China (No. 60675024)  相似文献   

15.
交通事故特征受地域分布影响显著,本文对交通事故特征进行优化聚类研究.基于 2019年无锡市交通事故数据,调用开放地图接口地理编码解算事故地点经纬度,使用密度聚类算法对事故地点与事故原因进行密度聚类.传统的密度聚类算法依赖距离阈值和样本数阈值的准确输入,为解决这一局限,建立一种自适应搜索距离阈值和样本数阈值的密度聚类模型,并与原始聚类模型进行对比.结果表明,优化算法在参数确定上更加智能,对簇的划分更加准确,对噪声点的识别更加合理.通过机器学习中轮廓系数计算方法计算模型得分,证明了该算法在城市道路交通事故地理位置聚类中的适用性.  相似文献   

16.
为准确计量公交区域时刻表优化过程中,客流出行与企业运营博弈产生的社会效益,构建兼顾随机客流需求和时刻表运行能效的双层规划模型。从公交乘客出行量与质的角度,分析随机客流需求与时刻表之间的互动关系;依据出行性质将客流需求分层细化,作为下层弹性需求交通网络流模型的输入;考虑客流需求、乘客出行效率及企业运营成本间的波动关系,设计公交区域时刻表运行能效作为上层模型的优化目标;采用Dial-MSA与遗传算法求解双层规划模型。实例计算结果表明,优化后的公交区域时刻表运行能效提高了7.3%。可见,优化后的公交区域时刻表更能满足客流需求,有效地提高时刻表运行能效,更好地实现动态适应性。  相似文献   

17.
已有城市轨道交通车站分类多基于定性分析,不能满足精细化设计和运营的需要。本文提出一种基于聚类站点公共特征的站点精细分类方法。首先,将来源于AFC(Automatic Fare Collection)的进站客流量数据处理为时间序列数据,并基于K-Means++算法对各个站点的客流量进行聚类;其次,建立客流量聚类结果与土地利用特征多维参数的拟合方程,计算获得居住密集型、工作就业型以及区域中心型等5种大类站点的客流量公共特征。在此基础上,充分考虑属于同一大类站点不同站点的细分特性,使用5类客流量公共特征比重组合精细描述具体站点类型。 实例结果表明,使用本文提出的精细分类方法计算得到的每个站的客流量拟合值与真实客流值间的平均绝对百分比误差控制在14%以内,说明该分类方法具有可行性。  相似文献   

18.
为有效解决高流量终端区内标准飞行模式、非标准飞行模式和异常飞行模式难以自动分离的问题,采用广泛记录的广播式自动相关监视(ADS-B)数据,构建了基于稳健深度自编码器(RDAE)和快速搜索并寻找密度峰值的聚类(CFSFDP)算法的航迹聚类模型; 使用RDAE降维提取终端区内航迹集的非线性特征,利用多种正则化手段约束内部低维流形,以重建更紧密的航迹并将其作为CFSFDP算法的输入,利用轮廓系数选取不同密度飞行模式的聚类中心,并调节边缘密度参数识别出异常航迹; 选取主成分分析(PCA)结合有噪声的空间密度聚类(DBSCAN)算法、动态时间规整(DTW)结合DBSCAN的2种常用航迹聚类模型作为对比项,分别在广州白云机场1 d的少量数据和45 d的大量数据上进行试验。分析结果表明:DTW与CFSFDP的结合模型在少量数据集上具有最优的航迹聚类性能,轮廓系数比对比项分别提升了62%和28%,且可以自动识别出遵循区域导航标准飞行模式的航班和特定环境下遵循管制偏好的非标准飞行模式的航班,识别异常航迹的精确度也分别提高了57%和10%;大量数据下,提出的RDAE结合CFSFDP模型的聚类性能比经典的PCA结合DBSCAN算法提升了13%,且具备可接受的时间复杂度。由此可见,建立的终端区飞行模式区分模型可为空域级交通流性能评估和航班级航迹预测与优化提供数据提取平台。   相似文献   

19.
交通事故特征受地域分布影响显著,本文对交通事故特征进行优化聚类研究.基于 2019年无锡市交通事故数据,调用开放地图接口地理编码解算事故地点经纬度,使用密度聚类算法对事故地点与事故原因进行密度聚类.传统的密度聚类算法依赖距离阈值和样本数阈值的准确输入,为解决这一局限,建立一种自适应搜索距离阈值和样本数阈值的密度聚类模型,并与原始聚类模型进行对比.结果表明,优化算法在参数确定上更加智能,对簇的划分更加准确,对噪声点的识别更加合理.通过机器学习中轮廓系数计算方法计算模型得分,证明了该算法在城市道路交通事故地理位置聚类中的适用性.  相似文献   

20.
文章分析了高职院校科研经费管理现状及存在的主要问题,提出了高职院校有效实施科研经费管理的改进措施,通过精细化地财务管理不断提升科研经费管理的有效性、服务水平和资金使用效益。  相似文献   

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