H∞ control for stochastic systems with time-delay

The H∞-control problem of stochastic systems with time-delay is considered. The sufficient conditions are obtained, under which there are always state-feedback control and dynamic output-feedback control so that the resulting closed-loop system is internaly stable and L2 input-output stable in the sense of expectation. Furthermore, the explicit formulas of both kinds of controls are derived. An example is included to illustrate the correctness of theoretic results.     

一种基于H.264的细粒度多适应性视频编码算法

提出了一种基于H．264的细粒度多适应性编码算法并对其进行了仿真实验。该算法综合运用了MP(Matching Pursuit)变换和位面编码等细粒度编码技术，灵活地将MP变换结果分为两个层次的码流，帧间预测也采用了两级预测模式，生成了多层次细粒度的视频压缩码流。该算法输出码流具有精细可调性，能自适应网络带宽变化，对于解决视频应用在现有尽力而为网络上所面，临的带宽波动和异构等问题有着重要意义。仿真实验证明了该算法的恢复质量和可伸缩性。     

4×4整数变换的流算法研究

4×4整数变换是H.264视频压缩标准的关键技术之一,对H.264编解码器的整体性能有重要影响。基于流处理的思想,提出了一种适用于H.264整数变换的混合流式变换算法MSTA,并将其映射到了Imagine流处理器上。实验结果表明,MSTA流实现处理一次4×4整数变换仅需4.5ns,远超出当前实时应用的需求。另外,流处理器良好的灵活性将使MSTA拥有更广阔的应用前景。     

一种穿越NAT/FW的有效方案——基于H.323集中式视频会议系统

以H.323建议的集中式视频会议系统为平台,论述了NAT/FW障碍的形成和穿越NAT/FW的原理,提出了一种穿越NAT/FW的方案,给出了软件实现的部分代码.实际运行表明,该方案是一种行之有效的软件方案,应用该方案可使H.323集中式视频会议系统有效穿越NAT/FW障碍.     

非负函数积分均值的一个不等式性质

利用Hlder不等式证明有界闭区间上非负连续函数积分均值的一个不等式性质,将其推广到与函数整数次幂的积分有关的序列的单调性,并证明该序列的极限即为函数在积分区间上的最大值.     

Jordan区域间共形映照的Holder连续性

本文给出了Ｊｏｒｄａｎ区域边界点的阶的定义,讨论了两Ｊｏｒｄａｎ区域间共形映照在边界点处的连续阶与对应边界点的阶的两两间的关系．     

H（M）zsm—5杂质子表面酸性的研究

本文用ＣＮＤＯ／２方法，研究了不同Ｈ（Ｍ）ＺＳＭ－５杂原子沸石的表面酸性，优化了杂原子的成键参数，结果表明，沸石表面Ｂ酸性与羟基质子电荷顺序一致，用气相脱质子能预测杂原子沸石表面酸性，与实验符合很好。     

关于《对偶空间X中具有H性质的定理》的一点注记

本文以两个反例证明中主要结果:若对偶空间X~*可分,则小X~*具有H.性质。(2)X范数Gateaux可微与Frechert可微等价是错误的。     

解析芝诺悖论内含的逻辑漏洞

本文回顾了亚里士多德等人对芝诺悖论的一些看法，指出寻找该悖论推理过程逻辑漏洞的必要性，并试图给出对追龟辩和飞矢辩不同于亚里士多德、罗素等人的分析。     

Molecular mechanisms in therapy of acid-related diseases

Inhibition of gastric acid secretion is the mainstay of the treatment of gastroesophageal reflux disease and peptic ulceration; therapies to inhibit acid are among the best-selling drugs worldwide. Highly effective agents targeting the histamine H2 receptor were first identified in the 1970s. These were followed by the development of irreversible inhibitors of the parietal cell hydrogen-potassium ATPase (the proton pump inhibitors) that inhibit acid secretion much more effectively. Reviewed here are the chemistry, biological targets and pharmacology of these drugs, with reference to their current and evolving clinical utilities. Future directions in the development of acid inhibitory drugs include modifications of current agents and the emergence of a novel class of agents, the acid pump antagonists. Received 30 May 2007; received after revision 15 August 2007; accepted 13 September 2007