广义双向S-粗集和它的一般结构

基于双向S-粗集和一般二元关系吼，提出广义双向S-粗集，对广义双向S-粗集的一般结构进行了描述。对广义双向S-粗集的有关性质进行了讨论。并给出了具体实例和意义解释。广义双向S-粗集为研究一般系统动态的近似特性提供了新的途径和方法。     

Banach空间混合型积分-微分方程初值问题的唯一解

在不使用任何紧型条件的假设下 ,得到Banach空间中一类非线性混合型积分 -微分方程初值问题的唯一解、解的迭代逼近序列以及误差估计     

一般二元关系下的粗糙度不等式

由等价关系尺所决定的近似空间（U,R）上，可用精度和粗糙度来表示集合的完全程度和不完全程度。本文将精度和粗糙度推广到满足自反性的二元关系所决定的广义近似空间上，并相应地给出了粗糙度不等式，同时讨论了当关系R满足自反性时，粗糙度也有同等价关系决定的近似空间上一样的包容排斥定理。     

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

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.     

体操运动员前臂运动特征及其发展特点的研究

采用直观半圆仪,对我国441名体操运动员和563名青少年儿童的前臂屈伸复制运动误差值作了测定和比较分析等研究,结果发现,就这个非专业性的和极为普通的动作——前臂屈伸运动的准确性来讲,在运动等级不同的体操运动员之间以及体操运动员与同年龄的普通人之间,都存在明显的差别。而且,这种运动准确性较高者,学习基本体操动作的成效优于准确性较低者。这种运动的准确性在7～11岁期间提高最快,12～22岁时呈波浪式的发展状态;在体操运动训练的作用下,这种运动的准确性,在9～13岁加速提高,而且,随后的波浪式变化明显减小。     

Dimensions of Norm-Referenced Compulsory School Grades and their Relative Importance for the Prediction of Upper Secondary School Grades

Irrespective of the grading system, grades are the most valid instrument for predicting educational success. Previous studies have shown that criterion-referenced compulsory school grades are multidimensional, reflecting subject-specific dimensions and a common grade dimension, both of which contribute to the predictive validity of grades. This suggests that in addition to knowledge and skills, grades reflect other aspects which might have importance for the prediction of educational success. The purpose of this study was to investigate, using structured equation modeling, whether norm-referenced compulsory school grades display similar patterns of dimensionality and predictive validity to criterion-referenced grades. Possible differences due to gender and parents' education were considered. Participants were 3855 students born in 1972. The results showed that norm-referenced grades are multidimensional, and that both the subject-specific and common grade dimensions contribute to predicting educational success. In the common grade dimension, girls and students with higher educational backgrounds were favored.     

距离空间中上半连续函数的定义及等价条件

根据距离空间中函数在某点的上极限、下极限的定义及函数在某点上半连续、下半连续的定义,证明了函数在某点上半连续的等价条件.     

积分上限函数的具体化问题

高等数学中原函数的存在定理是重要的,但其逆定理并不成立.有些新编教材在习题中忽视了逆定理不成立这一事实,从而导致积分上限函数的具体化出现问题.要解决积分上限函数的具体化问题,必需要了解积分上限函数与原函数之间的关系.     

庄子“无为不治”思想简析

从《庄子》全书的总体内容看,“上无为而下有为”的思想不是庄子的思想,它应该是夹杂在《庄子》一书中的其它思想流派的东西——是儒家的甚至法家的南面术,与庄子的思想是格格不入的。庄子的思想应该是“无为不治”。建立在“无为不治”的思想基础上,庄子对仁义,即通常的社会规范制度进行了猛烈的抨击。     

关于粘性导数的几个性质的探讨

M .G .Crandall等人在文 [1]中给出了函数的粘性导数的概念。在这个概念的基础上我们讨论了函数的粘性导数的上 (下 )导集的几个性质 :在函数可微点处的性质、闭凸性质、与C1类函数的和的性质、与C2 类函数的差在严格局部极大 (小 )值点的性质。