Static and dynamic accuracy of a magnetic-inertial measurement unit used to provide racket swing kinematics     

Benjamin Kane Williams  Ross H. Sanders  Joong Hyun Ryu  Pitre C. Bourdon  Philip Graham-Smith  Peter J. Sinclair 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(2):202-214

Magnetic-inertial measurement units (MIMUs) are becoming more prevalent in sports biomechanics and may be a viable tool to evaluate kinematic parameters. This study examined the accuracy of a MIMU to estimate orientation angles under static conditions and dynamically from a squash racket during a forehand drive shot. A MIMU was mounted onto a goniometer and moved through 0–90°, with static data collected at 10° increments during 10 repetitions of all three axes. Typical error analyses showed the MIMU to be very reliable (TE ≤ 0.03°). MIMU accuracy was determined via intraclass correlation coefficients (ICC) (r > 0.999, p < 0.001). An ordinary least products regression showed no proportional bias and minimal fixed bias for all axes. Dynamic accuracy was assessed by comparing MIMU and optical motion capture data of squash racket swing kinematics. A MIMU was fixed onto a racket and 10 participants each hit 10 forehand shots. Mean orientation angle error at ball impact was <0.50° and ICC showed very high correlations (r ≥ 0.988, p < 0.001) for all orientations. Swing phase root mean squared errors were ≤2.20°. These results indicate that a MIMU could be used to accurately and reliably estimate selected racket swing kinematics.  相似文献   

基于隐马尔科夫模型的VLCC目的港预测     

杨春  王一丹  徐晖  胡勤友  潘亚兰 《上海海事大学学报》2020,41(4):42-49

超大型油船(very large crude carrier，VLCC)目的港预测对海运原油流向预测以及货源地未来运力估计具有重要作用。针对VLCC的AIS目的港信息存在缺失、更新不及时、不准确等现象，提出一种基于隐马尔科夫模型的VLCC目的港预测方法。分析船舶AIS轨迹数据，得到油船历史停靠港口序列；根据VLCC轨迹提取习惯航路，以航路中的交叉点为依据设置观测线；利用船舶航行轨迹数据判断船舶是否经过观测线以及经过观测线的方向，对不同方向分别计算船舶在挂靠港间的转移概率矩阵和船舶挂靠港与观测线间的输出概率矩阵，建立VLCC目的港预测模型并进行预测。研究结果表明：在大多数情况下VLCC目的港预测的准确率可以达到70%以上；航线越固定、运行越规律的船舶，预测准确率越高；船舶越靠近目的港，预测越准确；重载状态下的船舶目的港预测更准确。  相似文献   

Digital Module 07: Subscores: Evaluation and Reporting https://ncme.elevate.commpartners.com     

Sandip Sinharay 《Educational Measurement》2019,38(3):114-115

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Statistical learning for OCR error correction     

Jie Mei  Aminul Islam  Abidalrahman Moh’d  Yajing Wu  Evangelos Milios 《Information processing & management》2018,54(6):874-887

Modern OCR engines incorporate some form of error correction, typically based on dictionaries. However, there are still residual errors that decrease performance of natural language processing algorithms applied to OCR text. In this paper, we present a statistical learning model for post-processing OCR errors, either in a fully automatic manner or followed by minimal user interaction to further reduce error rate. Our model employs web-scale corpora and integrates a rich set of linguistic features. Through an interdependent learning pipeline, our model produces and continuously refines the error detection and suggestion of candidate corrections. Evaluated on a historical biology book with complex error patterns, our model outperforms various baseline methods in the automatic mode and shows an even greater advantage when involving minimal user interaction. Quantitative analysis of each computational step further suggests that our proposed model is well-suited for handling volatile and complex OCR error patterns, which are beyond the capabilities of error correction incorporated in OCR engines.  相似文献   

布朗运动对油滴实验的影响     

欧海峰  王会永 《实验技术与管理》2007,24(7):38-40,54

以往，布朗运动对油滴实验产生的影响都只是作定性的描述。该文利用统计物理中布朗微粒方均位移的表达式，导出布朗运动引起的时间误差公式，推导了3种包含布朗运动的误差与不包含布朗运动的误差的比值公式，并作出相应的曲线图和曲面图进行直观的分析，得出的结论是：布朗运动对油滴实验的影响是很明显的。  相似文献   

翻转课堂的误区及路径选择     

杨新燕  查晓虎 《宿州教育学院学报》2021,(1)

翻转课堂作为“互联网+教育”的产物受到了许多学者的青睐,但是在实施过程中翻转课堂的优势并没有真正发挥出来,随着实践的不断深入,翻转课堂的误区越来越明显。文章从厘清翻转课堂的概念出发,发现翻转课堂存在罗列书本内容、翻转形式机械运用、教师职能弱化、评价标准缺失的误区,并提出走出翻转课堂误区的路径,如科学规划教学内容、处理好“放手”与“松手”的关系、培养学生提出问题的能力、完善评价制度,以更好地促进翻转课堂的实施。  相似文献   

油气勘探开发论文题名英译常见谬误简析   总被引：2，自引：0，他引：2  

王大锐  Jin Jisuo  Liu Chengjie 《编辑学报》2006,18(4):262-263

根据对<石油勘探与开发>近千篇论文英文摘要的编校实践,列举出油气勘探开发论文题名英译出现的一些问题,并进行简析.  相似文献   

前期差错更正所得税的会计处理     

段悦兰 《科技创业月刊》2007,20(11):60-60,75

企业在会计核算过程中可能会发生各种各样的差错,产生错账。错账会影响财务报表使用者对企业财务状况、经营成果和现金流量作出正确判断。就企业发现重要的前期差错时,对前期差错更正涉及到所得税时如何进行会计处理进行了探讨。  相似文献   

滚齿机床工作台偏差数据采集与补偿系统     

章赞  陶晓杰 《中国科技信息》2005,16(18):21-22

本文介绍一种基于PC的数控滚齿机床工作台偏差数据采集与补偿系统。该系统充分利用了一块AC6011数据采集卡实现了多路采集与控制功能,结合PC机强大的数据处理功能与软件的良好支持,实现了智能数据采集与补偿系统的低成本开发。  相似文献   

自动化系统运行中出现的操作失误、服务失败及补救措施     

刘菊霞 《现代情报》2007,27(12):130-132,135

本文概括性地列举了流通部读者服务工作中出现的操作失误和服务失败的类型、成因、后果及补救措施，系统、全面地论述了如何在管理制度、工作程序、技术层面和服务意识上下功夫，制定预防和解决在读者服务过程中出现操作失误和服务失败的长效机制。  相似文献