一类非线性连续奇异系统降维观测器的设计

讨论了一类非线性时间连续奇异系统观测器的设计问题,通过线性矩阵不等式,给出了一种易于计算的降维观测器的设计方法;仿真数值例子表明了所给设计方法的有效性。     

概率方法建模预测分数线

结合建模的步骤，运用回归分析、假设检验、正态分布等工具预测分数线。     

基于改进的DTW算法的仿真与分析

传统的DTW算法着重于时间规整和间距测量的概念，对数据的可靠性没有进行有效的分析，且对连续词的识别效果不明显。基于松弛起始点和分段思想的改进DTW算法，可以改善明阿算法的缺陷。通过对语音样本0．9在MATLAB6．5上的仿真实现与分析表明，采用改进后的DTW算法具有良好的语音识别效果。     

变系数一阶线性时滞微分方程的一个可积判据

首先引入广义周期函数的概念．然后给出了变系数一阶线性时滞微分方程的一个实用的可积充分判据，从而扩大了常微分方程的封闭求积范围．     

关于节点电压法中多余元件的分析

节点电压法是电路分析的重点,它是分析处理线性电路的基本方法和常用手段,得到广泛的应用．在应用该方法列写节点电压方程时,将某些元件作为多余元件处理可以使电路的求解更为简便．那么,哪些元件可以视为多余元件?其前提是什么?本文就这一问题进行了讨论．     

线性方程组求解及应用

文章首先介绍了用克拉默法则求解一类线性方程组(方程的个数与未知量个数相同且系数行列式不为零),由此提出对于一般的线性方程组如何求解问题.从而引出用矩阵的秩来判定线性方程组的解的结构以及用初等变换来求线性方程组的通解.最后应用线性方程组的求解问题对矩阵方程和向量组的线性相关性进行分析.     

邮件服务器中基于地址的一种电子邮件过滤方法

互联网是一个无政府世界，有些人利用电子邮件肆意散发邮件广告，导致很多人的邮箱垃圾成堆；有些人利用电子邮件制造邮件炸弹，要么使电子邮件服务器瘫痪，要么使别人无法正常使用电子信箱；还有更坏的人利用电子邮箱传播电脑病毒．本文针对UNIX系统中的邮件服务器，阐述了通过使用Sendmail配置邮件中继域文件relay-domains和Ac-cess文件防止邮件攻击的技术．     

Comparing Student Performance and Growth in 2- and 4-Year Institutions

This study examines the organizational characteristics of 51 higher education institutions in relationship to student performance and growth. The study first finds that organizational measures of mission, size, wealth, complexity, and selectivity are statistically represented by the 2-year versus 4-year college mission. Findings indicate that 2-year and 4-year campuses indeed do exert significantly different influences on undergraduate GPA and self-reported intellectual growth. Next, the study uses both OLS regression and HLM to examine these influences. High school percentile rank and college classroom experiences are better predictors of Cum GPA at 4-year institutions, while student effort is a better predictor of GPA at 2-year institutions. Whereas the most important predictors of Cum GPA include precollege measures such as high school percentile rank and SAT score, the most influential predictors of student intellectual growth are campus experiences including classroom vitality, peer support, student effort, commitment, and involvement. Controlling for all other variables, students at 2-year institutions receive higher grades, and students at 4-year campuses experience more growth.     

椭球约束下混合模型的线性极小极大估计

给出在椭球约束下带随机信息的混合模型的线性极小极大估计b(2 ) ,讨论了b(2 ) 在MDE-Ⅱ准则下相对于经典回归模型在椭球约束下的线性极小极大估计b(1) 的优良性 ,并得出了b(2 ) 比b(1) 优的一个充分条件     

丁广义割圆序列的线性复杂度

Minimal polynomials and linear complexity of binary Ding generalized cyclotomic sequences of order 2 with the two-prime residue ring Zpq are obtained by Bai in 2005. In this paper, we obtain linear complexity and minimal polynomials of all Ding generalized cyclotomic sequences. Our result shows that linear complexity of these sequences takes on the values pq and pq-1 on our necessary and sufficient condition with probability 1/4 and the lower bound （pq - 1）/2 with probability 1/8. This shows that most of these sequences are good. We also obtained that linear complexity and minimal polynomials of these sequences are independent of their orders. This makes it no more difficult in choosing proper p and q.