7维二步幂零李代数的分类

用具体构造的方法,选取合适的极小生成元系,给出了不可分解的7维二步幂零李代数的分类.     

球面、复射影空间中的子流形

本文研究了S^n p中的n雏紧致全实极小子流形的一类Schrǒdinger算子的第一特征值，得到了一个它的上界的估计，并由此给出它的一个重要应用．     

Application of causality diagram in system safety analysis

Causality Diagram （CD） is a new graphical knowledge representation based on probability theory. The application of this methodology in the safety analysis of the gas explosion in collieries was discussed in this paper, and the Minimal Cut Set, the Minimal Path Set and the Importance were introduced to develop the methodology. These concepts are employed to analyze the influence each event has on the top event - the gas explosion, so as to find out about the defects of the system and accordingly help to work out the emphasis of the precautionary work and some preventive measures as well. The results of the safety analysis are in accordance with the practical requirements; therefore the preventive measures are certain to work effectively. In brief, according to the research CD is so effective in the safety analysis and the safety assessment that it can be a qualitative and quantitative method to predict the accident as well as offer some effective measures for the investigation, the prevention and the control of the accident.     

图的支配集的有效算法

给出了利用命题逻辑公式的析取范式和主析取范式求图的全部极小支配集和最小支配集以及全部极小边支配集和最小边支配集的一般算法     

On the Use and Usefulness of Stress Diacritics in Reading Greek

The assignment of stress when reading Greek can be based on lexical and orthographic information. One hundred and seventy seventh-grade children read lists of isolated words and pseudowords. A large proportion of stress assignment errors were made in pseudoword reading, especially on the items that do not follow the most frequent penultimate stress pattern. Analysis of text corpora indicates that ignoring written stress diacritics would result in less than 1% errors, without taking into account disambiguating effects of context. It is tentatively suggested that, in reading Greek, stress assignment is primarily lexical. The results are consistent with a hypothesis that the bisyllabic trochee is the default metrical frame in Greek.     

关于Diophantine方程x^3-1=Dy^2（D=p,2p）

运用Pell方程px^2-3 y^2=1的最小解、同余式、平方剩余、勒让德符号等初等方法,证明了p是6k＋1型的奇素数时,Diophantine方程x^3-1=Dy^2（D=p,2p）正整数解的情况.     

Visual Search and Biological Motion Perception in Tennis

Purpose

The purposes of this study were to: (a) examine the effect of experience and goal constraints (speed, accuracy) on kicking patterns; (b) determine if effective striking mass was independent of ankle velocity at impact; and (c) determine the accuracy of kicks relative to independent factors.

Method

Twenty participants were recruited to kick at 3 different velocities with and without an accuracy requirement. Multivariate analysis of variance determined if relative timing of joint angular velocities changed during the kick. Chi-square analysis determined if calculated effective mass was independent of ankle velocity at impact. Analysis of variance (ANOVA) was used to examine differences in absolute constant error and variable error according to independent factors.

Results

Results indicated that experience and speed affect absolute timing of joint velocities with no changes in the relative timing of peak joint velocity across independent factors. Chi-square analysis indicated that calculated effective mass is not independent of ankle velocity. ANOVA indicated that experienced performers displayed less variability error than did inexperienced performers.

Conclusion

It was concluded that: (a) Experience, velocity, and accuracy do not affect the relative timing of kicks; (b) kickers trade ankle velocity at impact for greater effective striking mass and ball velocity; and (c) variability in ball placement is affected by experience.     

含公布电源配电网可靠性的评估方案研究

在原有配电网引入分布式电源的情况下,提出一种基于应用改进最小路法结合可靠性指标求解评估含分布式电源distributed generation（DG）的配电网可靠性评估方案。以IEEE-RBTS Bus6 系统为例进行不同方案的仿真。仿真结果表明,所提出的可靠性评估模型可以明显地改善配电网系统对用户提供电能的可靠性。     

计算机网络可靠性的分析研究

本文首先介绍了计算机网络系统的概念和可用于计算机网络系统的集中可靠性分析的相关概念及方法,然后着重于对本文要采用的节点遍历法等一些算法做了算法分析和具体实现,使繁杂的算法易于理解。并在对一般节点遍历法的理论分析的基础上对改进后的节点遍历法进行了较深入的探讨。网络系统可靠性数值计算量大而烦琐,改进后的节点遍历法可以大大减少其运算量。因此对现有算法的改进是十分有意义的。     

多变量系统状态反馈型的闭型解

基于广义逆矩阵的理论和Bellman最优性原理,给出了多输入多输出(MIMO)系统状态反馈型闭型解。对最优终端控制问题作了进一步的详细研究,导出了终端控制误差和控制能量与控制时间的关系。