即时通信关键技术及实现模式研究

本文概述了VoIP技术的定义,探讨了VoIP的基本原理,对其关键技术做了详细分析,并指出了VoIP的发展趋势及应用。     

一类中立型非线性扰动不确定时滞系统的H∞问题

主要讨论了利用LMI求解一类中立型非线性扰动不确定时滞系统的H∞性能问题.首先讨论了无扰动系统的稳定性,接着通过构造无记忆状态反馈控制器,给出使闭环系统具有一定的鲁棒性和H∞性能的充分条件.     

诺亚与埃克斯坦比较教育功能理论述评

诺亚和埃克斯坦的比较教育功能理论是在实证主义研究范式的影响下逐渐形成的,并在长期的教育科研实践中走向成熟。他们对比较教育功能的阐述可以集中概括为教育信息的普及功能、教育认识的标准功能、教育规划的决策功能以及教育规律的推导功能四个方面,并呈现出逐级递进的态势,在构建与完善比较教育科学量化研究方法和勾勒比较教育的发展框架上发挥了重要的作用。诺亚与埃克斯坦的比较教育功能理论体系以鲜明的实践导向性为比较教育与教育改革的充分整合提供了科学的参照标准。     

关于非奇H矩阵某些迭代的谱半径

当系数矩阵A是非奇H矩阵时,通过分析求解线性方程组的雅可比、高斯塞德尔和超松弛方法的迭代矩阵特征值,得出相关谱半径的性质,进而将雅可比迭代和高斯塞德尔迭代收敛的充分条件由A为严格对角占优矩阵放宽到A为非奇H矩阵,同时证明了此时低松弛迭代也是收敛的．     

与H（·，·）-增生映射相关的广义变分包含

引入和研究了与H（·,·）-增生映射相关的广义变分包含．借助预解算子,给出了与H（·,·）-增生映射相关的广义变分包含的迭代算法和收敛定理．     

带有扰动项的拟线性椭圆方程正解的存在性

在H0^1,k（Ω）空间中研究了一类带有扰动项的耘线性椭圆方程问题正解的存在性．利用变分原理和一种山路引理的变形,证明了当h（x,u）满足一定条件并且f（x,u）是拟线性时,其正解在H0^1,k（Ω）空间中是存在的．     

Calderón-Zygmund算子在H1(Rn)空间上的有界性

文章证明了Calderon-Zygmund算子从H1(Rn)到h1(Rn)(局部Hardy空间)有界.     

An “Ideal” Home for Care: Nel Noddings,Thomas Hill Green,and an Ontological Support for a Phenomenology of Care

This paper is grounded in a deep appreciation of Nel Noddings’ “ethics of care” as an important contribution to moral philosophy and moral education. We seek to offer some philosophical reflections that have the potential to strengthen this important alternative to mainstream ethics and to how moral education might be conceived and practiced differently. After identifying some ambivalence in Noddings’ own position toward abstract philosophy, and despite the practical reasons for this that we share, we then find grounds for pressing in this speculative direction, some of which indeed accord with Noddings’ own statements and philosophical concerns. To show how such further philosophical reflection upon her relational morality could help, we focus on elaborating a perspective on ontological issues that we find in the work of Thomas Hill Green, a 19^th century idealist, and seek to show its compatibility with Noddings’ more pragmatic stance. A concluding point addresses, and dispels, a possible worry that the grand narrative structure of Green’s idealism might undercut Noddings’ aim of having an ethic that is melioristic and open.     

Effects of school choice on the margin: The cream is already skimmed

Critics of school choice argue that cream-skimming will worsen outcomes for those left behind in public schools. Since “high ability” families may have already sorted themselves out of the schools in question, this paper will examine whether existing within-school heterogeneity leaves any scope for cream-skimming to operate. It asks, “given the current level of within-school heterogeneity, how strong would peer effects have to be to significantly worsen outcomes for those left behind?” In order for cream-skimming to lower math test scores by one half-year's progress, the peer effect would have to be as strong as increasing class sizes by 8–20 students, or cutting per-student funding by $400–2000. These results indicate that current levels of within-school heterogeneity are so low that peer effects would have to be unrealistically strong to give cream-skimming any bite.     

关于《恋爱中的女人》“死亡”主题的思考

《恋爱中的女人》是英国现代小说家劳伦斯的一部重要作品。在这部作品中,劳伦斯对西方工业文明的抨击达到了极至。他认为现代工业文明破坏了自然环境和人类本身,使得人类世界蒙上了死亡的阴影;劳伦斯在小说中主张以死亡消除死亡;但是小说的这个主题本身带有很大的局限性。