ROBUSTNESS OF PROCEDURES FOR THE BEHRENS-FISHER PROBLEMS: EXTENSION TO BIVARIATE NORMAL MIXTURES

In the applied sciences, it is often important to be able to compare the mean values of two populations. However, testing a hypothesis can be complex, if the two populations are heteroscedastic and exhibit non-normality in the data. This paper reviews currently available strategies for the multivariate Behrens-Fisher problem. It then carries out Monte Carlo comparisons of selected procedures to assess their robustness when applied to data from normal mixture distributions. The overall conclusion is that Johansen's procedure appears to work best for small sample data both in terms of empirical power and significance level. Johansen's procedure works reasonably well even with mixture data. The simulation also provides researchers with specific guidelines to follow at the early designing and planning stages of the investigation.     

非单调二元非线性算子方程组的迭代求解

利用锥与半序理论和混合单调算子理论 ,讨论 Banach空间中非单调二元非线性算子方程组解的存在性与唯一性 ,并给出收敛于方程组解的迭代序列和误差估计 ,改进和推广了混合单调算子方程和一元算子方程的某些相应结果 .     

克服制约因素 改善听力教学

听是语言学习的重要途径,是从声音信号中获取信息的主要手段。听力直接影响学习者对语言信息的接收和理解。听力的提高常受到一些主客观因素的制约。本文列举了这些不利因素并提出一些消除它们进而改善听力教学的方法。     

一阶常微分方程初值问题的上、下解与拟上下解的存在定理

利用上、下解与拟上下解方法讨论常微分方程问题时，文献均足假没上、下解与拟上下解是存在的，进而讨论方程的解．文章给出一阶常微分方程初值问题的上、下解与拟上下解的存在性定理，为利用上、下解与拟上下解方法讨论一阶常微分方程初值问题提供充分的依据．     

Sequence Independent Lifting in Mixed Integer Programming

We investigate lifting, i.e., the process of taking a valid inequality for a polyhedron and extending it to a valid inequality in a higher dimensional space. Lifting is usually applied sequentially, that is, variables in a set are lifted one after the other. This may be computationally unattractive since it involves the solution of an optimization problem to compute a lifting coefficient for each variable. To relieve this computational burden, we study sequence independent lifting, which only involves the solution of one optimization problem. We show that if a certain lifting function is superadditive, then the lifting coefficients are independent of the lifting sequence. We introduce the idea of valid superadditive lifting functions to obtain good aproximations to maximum lifting. We apply these results to strengthen Balas' lifting theorem for cover inequalities and to produce lifted flow cover inequalities for a single node flow problem.     

国有企业(上市公司)改革的症结与对策

国有企业 (上市公司 )存在的问题如上市公司不规范、法人财产权难以落实、资本功能残缺、内部人控制等是由各种原因促成的。作者认为政府的不适当干预是其症结所在 ,进而提出建立健全证券法规体系 ,推进国家股和法人股的流通 ,规范政府在经济中的行为等治理对策     

非线性波动方程的孤波解及余弦周期波解

利用假设待定法,求出了非线性波动方程的具有双曲正割函数分式形式且渐近值不为零的精确孤波解和余弦函数周期波解,并分别讨论了它们的有界性,揭示了行波波速改变对钟状孤波解与余弦函数周期波解波形变化的影响.     

我国公民新闻的发展现状与问题

为了界定“公民新闻”的概念以及探究“公民新闻”在中国的发展现状,运用比较研究的方法,结论认为“公民新闻”不同于“公共新闻”、“国民新闻”和“市民新闻”,它有着本质的规定性;中国“公民新闻”虽然有了一定程度的发展,但还处在初级实验阶段;“公民新闻”代表着新闻事业发展方向;中国“公民新闻”存在机制问题和“去农民化”倾向,只有政府、媒体和公众三方共同努力和协作,才能为“公民新闻”的健康发展创造一个良好的环境。     

艺术设计专业本科生毕业论文写作存在的问题及解决对策

艺术设计专业本科生毕业论文写作中存在着选题陈旧、没有新观点,论证材料多在网上下载且运用不合理、论证不严密等问题。这些问题不解决直接影响学生毕业论文的质量,而这些问题又不是一朝一夕所能解决的。重视基础理论教育,提高学生的理论水平,发挥教师的主导作用,将毕业论文与毕业设计作品紧密联系等方法,能够解决这些问题。     

具有非线性时滞的双曲型微分方程解振动的充分条件

给出具有非线性时滞的双曲型微分方程定解问题２ｕｔ２＝ａ（ｔ）Δｕ＋ｓｉ＝１ａｉ（ｔ）Δｕ（ｘ，ｔ－ρｉ（ｔ））－ｆ（ｘ，ｔ，ｕ）－ｋｊ＝１ｇｊ（ｘ，ｔ，ｕ（ｘ，ｔ－σｊ）），ｕ＝０，（ｘ，ｔ）∈Ω×〔０，∞），其中（ｘ，ｔ）∈Ω×（０，∞）的解振动的几个充分条件．