知识单元研究述评

知识单元是知识控制与处理的基本单位,是一切知识管理活动的前提和基础。文献单元、信息单元和知识单元是三种主要的知识单元形态。从知识单元的概念、特征、类型、比较和应用五个方面对当前知识单元研究现状进行了梳理和总结。知识单元在知识表达、知识组织、知识检索、知识计量、知识挖掘和知识发现等方面具有广泛的应用。参考文献114。     

延长高危潜油电泵井检泵周期方法的探讨

南堡油田某采油区电泵井总井数30口,其中电缆绝缘值低或者无绝缘的风险井18口,占电泵总井数的60%.为了防止这些高危电泵井躺井影响产量,针对这些高危电泵井加强了精细化管理,结合油井实际的生产状况,及时分析电流、压力、液面、泵工况、清蜡、加药等现场资料,摸索制定出高危潜油电泵井的现场管理方法,延长了油井的检泵周期.     

A Maximal Graded Exercise Test to Accurately Predict VO2max in 18–65-Year-Old Adults

The purpose of this study was to develop an age-generalized regression model to predict maximal oxygen uptake (VO_2max) based on a maximal treadmill graded exercise test (GXT; George, 1996) George, J. D. 1996. Alternative approach to maximal exercise testing and VO_2max prediction in college students. Research Quarterly for Exercise and Sport, 67: 452–457. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]. Participants (N?=?100), ages 18–65 years, reached a maximal level of exertion (mean?±?standard deviation [SD]; maximal heart rate [HR_max]?=?185.2?±?12.4 beats per minute (bpm); maximal respiratory exchange ratio [RER_max]?=?1.18?±?0.05; maximal rating of perceived exertion (RPE_max)?=?19.1?±?0.7) during the GXT to assess VO_2max (mean?±?SD; 40.24?±?9.11 mL·kg^?1·min^?1). Multiple linear regression generated the following prediction equation (R?=?.94, standard error of estimate [SEE]?=?3.18 mL·kg^?1·min^?1, %SEE?=?7.9): VO_2max (mL·kg^?1·min^?1)?=?13.160?+?(3.314 × gender; females?=?0, males?=?1) ? (.131 × age) ? (.334 × body mass index (BMI))?+?(5.177 × treadmill speed; mph)?+?(1.315 × treadmill grade; %). Cross validation using predicted residual sum of squares (PRESS) statistics revealed minimal shrinkage (R_p ?=?.93 and SEE _p ?=?3.40 mL·kg^?1·min^?1); consequently, this model should provide acceptable accuracy when it is applied to independent samples of comparable adults. Standardized β-weights indicate that treadmill speed (.583) was the most effective at predicting VO_2max followed by treadmill grade (.356), age (?.197), gender (.183), and BMI (?.148). This study provides a relatively accurate regression model to predict VO_2max in relatively fit men and women, ages 18–65 years, based on maximal exercise (treadmill speed and grade), biometric (BMI), and demographic (age and gender) data.     

Diagnosis and Monitoring of Basic Motor Competencies among Third-Graders in Luxembourg. An Assessment Tool for Teachers

ABSTRACT

Basic motor competencies (in German: Motorische Basiskompetenzen; MOBAK) are performance dispositions empowering children to participate in the movement culture. For the diagnosis of basic motor competencies, a test instrument consisting of 15 test items for assessing third graders’ basic motor competencies was developed (MOBAK-LUX-3) and validated empirically. Basic motor competencies were operationalized as test items in the form of basic motor qualifications, which are cultural tools formulated as a minimum standard. Data (MOBAK-LUX-3, age, gender, migration background, weight, height, sport club membership, weekly physical activity) were collected in 2015 amongst third-graders in elementary school in Luxembourg (N = 488; 50.4% female; M age = 8.8 years, SD = .51). A confirmatory factor analysis confirmed a four-factor structure (locomotion, object control, moving in water, object locomotion; CFI = .94; TLI = .92; RMSEA = .036; WRMR = 0.89). Five classes with different competence profiles were determined through latent class analysis. The MOBAK-LUX-3 test instrument satisfies test theory requirements and can be used to determinate motor competence profiles.     

The effects of surface traction characteristics on frictional demand and kinematics in tennis

The interaction between footwear and surfaces influences the forces experienced by tennis players. The purpose of this study was to investigate traction demand and kinematic adaptation during tennis-specific movements with changes in traction characteristics of surfaces. We hypothesised that players would increase the utilised coefficient of friction (horizontal to vertical ground reaction force ratio) when the shoe surface combination had a high coefficient of friction and flex their knee after contact to facilitate braking. Eight participants performed two separate movements, side jump out of stance and running forehand. Ground reaction force was measured and three-dimensional kinematic data were recorded. Clay surface and cushioned acrylic hard court (low vs. high shoe–surface friction) were used. The peak utilised coefficient of friction was greater on clay than the hard court. The knee was less flexed at impact on clay ( ? 5.6 ± 10.2°) and at peak flexion ( ? 13.1 ± 12.0°) during the running forehand. Our results indicate that tennis players adapt the level of utilised friction according to the characteristics of the surface, and this adaptation favours sliding on the low friction surface. Less knee flexion facilitates sliding on clay, whereas greater knee flexion contributes to braking on the hard court.     

Uneasy writing: The defining moments of high-stakes literacy testing

The authors report on an exploratory study that investigated Grade 10 students’ responses to a large-scale, high-stakes literacy test, the results of which determine high school graduation in Ontario, Canada. Through focus-group and individual interviews, the authors found that students perceived the test as evaluating their English skills rather than their cross-curricular literacy as is the stated purpose by the test administrators. Furthermore, the test contributed to students’ narrow definition of writing. Rather than promoting writing as a powerful tool for thinking and expressing ideas, students understood writing to be a fill-in-the-blanks response to particular genres. The authors conclude by pointing out the power of such tests to define unintended learning in schools.     

全球社群 云端学习——第16届全球华人计算机教育应用大会(GCCCE2012)综述

第16届全球华人计算机教育应用大会(GCCCE2012)由台南大学数字学习科技学系主办,于2012年5月28日至6月1日在台湾屏东县恒春垦丁福华饭店举行。大会以"全球社群、云端学习"为主题,期盼能够协同全球华人的数字学习研究,携手迈向新纪元。本次大会有来自美国、德国、墨西哥、新加坡、马来西亚、日本以及中国大陆、台湾、香港、澳门地区等地的学者及教师300多人参加。与会者就计算机辅助合作学习、人工智能教育应用、数字化教室、行动与无所不在学习、悦趣化学习与社会、科技于高等教育与人力绩效之应用、科技增强语言学习、政策及学习评估、数字科技、创新与教育等研究议题,以论文发表、教师论坛、博士生论坛与工作坊等形式进行了学术交流,为教育技术进一步发展提供新的机遇及挑战。     

三相短路电流计算的探讨

三相短路电流计算是供电系统设计、运行中必需进行的计算分析工作。三相短路电流计算的常用方法有欧姆法和标幺制法。通过对两种方法的比较分析,可以看出标幺制法的优越之处,以及两种方法均存在的缺陷,并在此基础上提出改进方法。     

标准化控制对CSY系列传感器与检测技术实验的成效影响

现实的实验教学效果结合务实的实验技艺改进,将以"稳妥环节、优化全局"的标准化控制模式,逐步深入并推进到具有典型"实验特色、标准特性"的传感器测试技术实验教学领域中,取得"质量把脉、基准全程"的标准化良好实验行为效果。以用"CSY产品系列传感器与检测技术"实验台为实践平台和简述背景,就实验过程中标准化排序控制和标准化理念控制对实验全过程产生的影响简要诠释,以及对实验器材的标准化定性问题进行归纳。     

测试技术教材建设与教学模式探讨

根据测试技术课程的特点,介绍了《机械工程测试技术》教材的内容和课程设置,提出了以典型工程案例为主线、多媒体与板书有机结合的教学模式,经过教学实践,取得了良好的效果。