Helical angle measurement of worm by a coordinate measuring machine and its uncertainty evaluation     

QIU Yong-you  KANG Shuang-yang  PENG Yun-feng  YANG Ping  HUANG Zi-qiang 《重庆大学学报(英文版)》2016,15(4):139-148

The purpose of the study concerns the measurement of worm’s helical angle by a coordinate measurement machine in the ambient industrial environment. The novel measurement method and sampling strategy were described firstly. This method used the coordinate measurement machine to measure both of the worm gear’s left and right surfaces. The worm surface was reconstructed based on the measured data of all the sampling points. Then a middle cylinder was established to truncate the fitted worm surfaces, and the truncated spiral lines were straightened to calculate the helical angle. The measurement uncertainty of worm’s helical angle was evaluated by taking the difference of calculated helical angles along the truncated spiral lines on both the left and right side surfaces of the worm. Twenty-four measurement experiments show that the maximum measurement error of the proposed method is 0.105, and the measurement error ratios are all less than 3.5?. The result means that the measurement method can realize the precision measurement of worm’s helical angle and can be employed in the generally industrial application.  相似文献   

试论艺术教育新理念     

成露霞 《河北师范大学学报(教育科学版)》2003,5(3):101-103

传统的艺术教育理念认为,艺术教育主要是培养人的综合艺术能力。随着时代的发展,这一传统理念已不适应艺术发展的需求。新理念认为:在培养人的综合艺术能力的同时,还应培养人们的整合创新、开拓贯通和跨域转换的多种能力,以促进人的全面发展。  相似文献   

核心概念与概念体系的建构理论   总被引：2，自引：0，他引：2  

欧阳景根 《华中师范大学学报(人文社会科学版)》2006,45(3):31-37

核心概念与概念体系是理论的基石,也是一种理论观点或一个理论体系是否具有解释力的关键所在。在科学研究中,为了使理论能够更好地解释新的现象,需要对原有各理论流派的核心概念与概念体系进行全面检视,对它们进行修正、抛弃或重新构建。本文把核心概念与概念体系分为理论观点型、理论体系型、学科型三种类型,并以两个案例为基础,从方法论的角度分析了在对学科进行反思与研究时,如何分析、审察并构建新的核心概念与概念体系。  相似文献   

现代期刊编辑的服务理念刍议     

尹晓红 《山西广播电视大学学报》2007,12(3):91-92

现代期刊编辑只有弄清服务对象,树立“以促进先进文化和先进生产力发展为己任”服务社会、“创造以人为本”的服务情怀,服务作者、服务读者的服务理念,不断提高自身的素质,才能增强社会责任感和历史使命感,实现编辑主体价值与历史责任的统一。  相似文献   

科研型数学教师及其培养   总被引：10，自引：3，他引：10  

郑强  杨世明 《数学教育学报》2002,11(3):72-74

国际经济、科技、人才的竞争正推动着教育的改革。教育改革的关键因素在于合格的、新型教师的培养。科研型教师是指既能教学，又能进行数学及数学教育研究的教师。科研型教师应具备3项条件：转变观念，更新意识，提高能力。科研型数学教师是新时代数学教育的需要，要实行理论学习、实践探索和科学研究三位一体的教师培训途径。教养科研型教师需要解决“为何搞科研”、“如何搞科研”和“研究什么”3个问题。  相似文献   

论廖家骅的音乐教育思想     

刘咏莲 《安徽师范大学学报(人文社会科学版)》2019,47(4):12-17

廖家骅先生作为当代中国音乐理论家、音乐教育家,为中国音乐教育学科的发展奠定了重要的基础,可称为“中国音乐教育学科的领路人”。基于对廖家骅学术成果的系统梳理,从其对音乐审美特性、音乐教育审美特性、音乐教育与审美心理和智力发展等方面的研究总结其音乐教育美育观;从其对高师音乐教育人才培养的职责、高师音乐教育培养目标等问题的关注概括其音乐教育通才观;从其对一线音乐教学、教育现状等现实问题与实践性问题的关注与评论提炼其音乐教育实践观,从而对他的音乐教育思想进行全面阐释。对廖家骅音乐教育思想的研究既是对我国音乐教育事业发展成就的总结与回顾,也是对我国当代音乐教育进一步发展的启示与借鉴。  相似文献   

一种凸轮升程误差的非接触式测量新方法     

傅师伟 《泉州师范学院学报》2004,22(6):39-44

分析现有几种凸轮升程误差测量方法的优、缺点后，提出一种基于图像处理的凸轮升程误差的非接触式测量新方法．理论分析和比较实验结果表明，该测量方法简便易行，测量精度较高，具有一定的应用价值．  相似文献   

Assessment of three-dimensional joint kinematics of the upper limb during simulated swimming using wearable inertial-magnetic measurement units     

Silvia Fantozzi  Andrea Giovanardi  Fabrício Anício Magalhães  Rocco Di Michele  Matteo Cortesi  Giorgio Gatta 《Journal of sports sciences》2016,34(11):1073-1080

The analysis of the joint kinematics during swimming plays a fundamental role both in sports conditioning and in clinical contexts. Contrary to the traditional video analysis, wearable inertial-magnetic measurements units (IMMUs) allow to analyse both the underwater and aerial phases of the swimming stroke over the whole length of the swimming pool. Furthermore, the rapid calibration and short data processing required by IMMUs provide coaches and athletes with an immediate feedback on swimming kinematics during training. This study aimed to develop a protocol to assess the three-dimensional kinematics of the upper limbs during swimming using IMMUs. Kinematics were evaluated during simulated dry-land swimming trials performed in the laboratory by eight swimmers. A stereo-photogrammetric system was used as the gold standard. The results showed high coefficient of multiple correlation (CMC) values, with median (first–third quartile) of 0.97 (0.93–0.95) and 0.99 (0.97–0.99) for simulated front-crawl and breaststroke, respectively. Furthermore, the joint angles were estimated with an accuracy increasing from distal to proximal joints, with wrist indices showing median CMC values always higher than 0.90. The present findings represent an important step towards the practical use of technology based on IMMUs for the kinematic analysis of swimming in applied contexts.  相似文献   

Rating of perceived exertion in maximal incremental tests during head-out water-based aerobic exercises     

Cristine Lima Alberton  Stephanie Santana Pinto  Tatiane Gorski  Amanda Haberland Antunes  Paula Finatto  Eduardo Lusa Cadore 《Journal of sports sciences》2016,34(18):1691-1698

  相似文献   

Accelerometer data requirements for reliable estimation of habitual physical activity and sedentary time of children during the early years - a worked example following a stepped approach     

Daniel D. Bingham  Silvia Costa  Stacy A. Clemes  Ash C. Routen  Helen J. Moore  Sally E. Barber 《Journal of sports sciences》2016,34(20):2005-2010

This study presents a worked example of a stepped process to reliably estimate the habitual physical activity and sedentary time of a sample of young children. A total of 299 children (2.9 ± 0.6 years) were recruited. Outcome variables were daily minutes of total physical activity, sedentary time, moderate to vigorous physical activity and proportional values of each variable. In total, 282 (94%) provided 3 h of accelerometer data on ≥1 day and were included in a 6-step process: Step-1: determine minimum wear-time; Step-2: process 7-day-data; Step-3: determine the inclusion of a weekend day; Step-4: examine day-to-day variability; Step-5: calculate single day intraclass correlation (ICC) (2,1); Step-6: calculate number of days required to reach reliability. Following the process the results were, Step-1: 6 h was estimated as minimum wear-time of a standard day. Step-2: 98 (32%) children had ≥6 h wear on 7 days. Step-3: no differences were found between weekdays and weekend days (P ≥ 0.05). Step-4: no differences were found between day-to-day variability (P ≥ 0.05). Step-5: single day ICC’s (2,1) ranged from 0.48 (total physical activity and sedentary time) to 0.53 (proportion of moderate to vigorous physical activity). Step-6: to reach reliability (ICC = 0.7), 3 days were required for all outcomes. In conclusion following a 7 day wear protocol, ≥6 h on any 3 days was found to have acceptable reliability. The stepped-process offers researchers a method to derive sample-specific wear-time criterion.  相似文献