变系数一阶线性时滞微分方程的一个可积判据     

张学元 《邵阳学院学报(社会科学版)》2003,2(5):9-13

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．  相似文献   

关于节点电压法中多余元件的分析     

张德珍  张德伟 《临沂师范学院学报》2006,28(3):44-46

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．  相似文献   

线性方程组求解及应用     

石擎天  黄坤阳 《教育教学论坛》2020,(12):325-327

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.  相似文献   

当前我国高校学术规范制度建设的构想   总被引：3，自引：0，他引：3  

邱咏梅 《德州学院学报》2005,21(5):87-90

加强学术规范建设,既需要道德自律,也需要制度他律.加强学术规范制度的建设必须整饬学术道德,规范学术研究,加强学术规范教育与训练,建构科学的学术评价体系,开展学术批评,加强学术反腐败制度建设,在学术工作中推动学风建设,创新科研管理制度等.  相似文献   

少数民族传统文化的法律保护     

牛文军 《内蒙古大学学报(人文社会科学版)》2002,34(6):32-37

在社会现代化与全球化进程中 ,如何处理好“全球一体化”与“文化多元化”的矛盾 ,是当代人类社会面临的主要挑战之一。关注现代化进程中的少数民族传统文化 ,运用法律手段保护少数民族传统文化是时代赋予我们的使命。为此 ,正确认识少数民族传统文化的特点 ,明确少数民族传统文化法律保护的原则 ,确立少数民族传统文化法律保护的内容及其规范体系具有重要意义。  相似文献   

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

Strauss  Linda C.  Volkwein  J. Fredericks 《Research in higher education》2002,43(2):133-161

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.  相似文献   

二阶方程组特征值边值问题的正解     

刘健 《临沂师范学院学报》2007,29(3):7-9

利用锥上的不动点指数定理研究了一类二阶方程组特征值边值问题正解的存在性,在λ充分小,f与g满足更广泛的条件下得到了两个正解,推广和改进了原有的结果.  相似文献   

椭球约束下混合模型的线性极小极大估计     

钱峰  周基元  殷晓晖  缪雪琴 《怀化学院学报》2004,23(2):13-16

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  相似文献   

丁广义割圆序列的线性复杂度   总被引：1，自引：0，他引：1  

闫统江  陈智雄  肖国镇 《上海大学学报(英文版)》2007,11(1):22-22

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.  相似文献   

Improving the learning of Boolean queries by means of a multiobjective IQBE evolutionary algorithm     

O. Cordón  E. Herrera-Viedma  M. Luque 《Information processing & management》2006

The Inductive Query By Example (IQBE) paradigm allows a system to automatically derive queries for a specific Information Retrieval System (IRS). Classic IRSs based on this paradigm [Smith, M., & Smith, M. (1997). The use of genetic programming to build Boolean queries for text retrieval through relevance feedback. Journal of Information Science, 23(6), 423–431] generate a single solution (Boolean query) in each run, that with the best fitness value, which is usually based on a weighted combination of the basic performance criteria, precision and recall.  相似文献