排序方式： 共有84条查询结果，搜索用时 15 毫秒
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针对现有步态识别研究中步态识别率低、算法单一等问题,提出了一种基于惯性运动传感器的步态识别方法。首先,该方法结合动态时间规整与人工神经网络,通过前者提取固定长度的步态特征,并设置成本函数的阈值来判别后者的正负输入,提取得到波形特征。其次,运用列文伯格-马夸尔特算法改进标准BP神经网络,最终完成步态识别。实验证明所提的改进步态识别方法将平均步态识别率和相等错误率维持在91.5%和9.1%,较好地提高了步态识别的准确率。因此,该方法可作为高级认证方法的补充,以增加个人信息的隐私和安全性,适合实验室仪器安全管理应用。 相似文献
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结合国内体育教学动态,设计并做实验研究了从“1”字形、“一”字形组合形式步法的教学方法,并将此方法与“十”字形步法的教学方法进行对比实验,以期摸索出一套在普通高校的羽毛球教学中行之有效的教学方法。 相似文献
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Cristine Agresta Christian R. Ward W. Geoffrey Wright Carole A. Tucker 《Sports biomechanics / International Society of Biomechanics in Sports》2018,17(2):206-215
Many field sports involve equipment that restricts one or both arms from moving while running. Arm swing during running has been examined from a biomechanical and physiologic perspective but not from an injury perspective. Moreover, only bilateral arm swing suppression has been studied with respect to running. The purpose of this study was to determine the influence of running with one arm restrained on lower extremity mechanics associated with running or sport-related injury. Fifteen healthy participants ran at a self-selected speed with typical arm swing, with one arm restrained and with both arms restrained. Lower extremity kinematics and spatiotemporal measures were analysed for all arm swing conditions. Running with one arm restrained resulted in increased frontal plane knee and hip angles, decreased foot strike angle, and decreased centre of mass vertical displacement compared to typical arm swing or bilateral arm swing restriction. Stride length was decreased and step frequency increased when running with one or both arms restrained. Unilateral arm swing restriction induces changes in lower extremity kinematics that are not similar to running with bilateral arm swing restriction or typical arm swing motion. Running with one arm restrained increases frontal plane mechanics associated with risk of knee injury. 相似文献
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Sam Khamis Barry Danino Shlomo Hayek Eli Carmeli 《Measurement in physical education and exercise science》2018,22(2):145-153
The aim of this study was to quantify clearance mechanics during gait. Seventeen children diagnosed with hemiplegic cerebral palsy underwent a three-dimensional gait analysis evaluation. Dynamic leg lengths were measured from the hip joint center to the heel, to the ankle joint center and to the forefoot throughout the gait cycle. Significant asymmetry was observed during stance, initial and terminal swing phases, where the hemiplegic limb was found shorter by using a paired t-test at 51 sample points (p < .05). The hemiplegic side was restricted in achieving maximal length during terminal swing. The ratio between the maximal dynamic leg length during the stance phase to minimal dynamic leg length during the swing phase was found higher on the non-involved side and lower on the hemiplegic side (p < .05). Quantifying clearance mechanics based on dynamic leg length can provide an additional insight into the analysis of gait patterns and might assist in detecting time of abnormal kinematic deviations. 相似文献
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第十九届全国运动生物力学学术交流大会于2017年10月13-16日期间在河北石家庄顺利召开。作为全国最大规模的运动生物力学大会,吸引了来自全国各地的学者的参与和关注。大会邀请众多国内外知名专家、学者作了相关研究的专题报告,展示了当前国内外在运动生物力学及其相关外延性研究方面的诸多实用性较强的研究成果,来自全国多所高校的学生以及体育相关研究所的学者纷纷投稿并参会。本次大会为各位专家、学者、科研人员以及在校大学生提供了一个学术交流的平台,对进一步加深高校与科研机构的学科交流、促进学科发展起到了重要的推动作用。 相似文献
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Micro-Doppler-based target detection and feature extraction in indoor and outdoor environments 总被引：1，自引：0，他引：1
In many cases, a target or a structure on a target may have micro-motions, such as vibrations or rotations. Micro-motions of structures on a target may introduce frequency modulation on the returned radar signal and generate sidebands on the Doppler frequency shift of the target's body. The modulation due to micro-motion is called the micro-Doppler (m-D) phenomenon. In this paper, we present an effective quadratic time-frequency S-method-based approach in conjunction with the Viterbi algorithm to extract m-D features. For target recognition applications, mainly those in military surveillance and reconnaissance operations, m-D features have to be extracted quickly so that they can be used for real-time target identification. The S-method is computationally simple, requiring only slight modifications to the existing Fourier transform-based algorithm. The effectiveness of the S-method in extracting m-D features is demonstrated through the application to indoor and outdoor experimental data sets such as rotating fan and human gait. The Viterbi algorithm for the instantaneous frequency estimation is used to enhance the weak human m-D features in relatively high noise environments. As such, this paper contributes additional experimental m-D data and analysis, which should help in developing a better picture of the human gait m-D research and its applications to indoor and outdoor imaging and automatic gait recognition systems. 相似文献
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Christian A. Clermont Lauren C. Benson Sean T. Osis Dylan Kobsar Reed Ferber 《Journal of sports sciences》2019,37(2):204-211
The purpose of this study was to classify runners in sex-specific groups as either competitive or recreational based on center of mass (CoM) accelerations. Forty-one runners participated in the study (25 male and 16 female), and were labeled as competitive or recreational based on age, sex, and race performance. Three-dimensional acceleration data were collected during a 5-minute treadmill run, and 24 features were extracted. Support vector machine classification models were used to examine the utility of the features in discriminating between competitive and recreational runners within each sex-specific subgroup. Competitive and recreational runners could be classified with 82.63 % and 80.4 % in the male and female models, respectively. Dominant features in both models were related to regularity and variability, with competitive runners exhibiting more consistent running gait patterns, but the specific features were slightly different in each sex-specific model. Therefore, it is important to separate runners into sex-specific competitive and recreational subgroups for future running biomechanical studies. In conclusion, we have demonstrated the ability to analyze running biomechanics in competitive and recreational runners using only CoM acceleration patterns. A runner, clinician, or coach may use this information to monitor how running patterns change as a result of training. 相似文献
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为了进一步探讨100m跑全程速度、步态变化及其在训练中人为控制的问题,研究首先采用纵向、横向比较分析的方法,对当前的研究成果进行分析,然后对于这些理论如何应用于实践作进一步探讨,以期发现100m跑速度节奏的基本规律和特点;研究的初衷希望能对当前理论予以整合并对其应用于训练实践的可操作性进行探讨。研究方法涉及文献资料法、专家调查法、回溯试验法、数理统计法、逻辑分析法等;结果表明：优秀运动员加速距离长的实质是速度储备大,我们训练中应当关注的是绝对速度的提高,应当强调的是动作速度,即有高步频保证的基础上来谈步长;作为步态特征的步长步频的变化是运动员高速跑中的自然协调,步长与步频应作为一个整体来理解才有意义,不同运动员个体其步长和步频是不相同的,也没有必要按照模型趋向一致的。对于具有一定训练基础之后的100m跑运动员的训练应当贯彻的指导思想是：1）速度训练为中心;2）提高加速跑阶段加速度;3）努力提高步频能力。 相似文献
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目的：研究有跌倒史老年人跨越障碍的步态特征。方法：运用美国 APAS 录像解析方法分析有跌倒史老年人（跌倒组10名）和无跌倒史老年人（对照组10名）跨越障碍时步态特征。结果：与无跌倒史老年人比较,有跌倒史老年人跨越步速、跨越高度、脚跟距离和脚尖距离有显著性差异（P <0.05）;有跌倒史老年人左腿（跟随腿）支撑踝关节最大伸展角度、右腿（先行腿）在障碍正上方踝关节角度、左腿在障碍正上方膝关节与踝关节角度有明显差别（ P <0.05）。由此发现有跌倒史老年人跨越障碍时具有跨越步速慢、脚尖距离长、脚跟距离短、左右腿跨越净高低的步态特征。 相似文献