上海贝尔 陆晓钧：IPTV需确保多业务的质量

IPTV改变了媒体和互动方式,用户可以在家里看电视、互动、交流,IPTV还能够改变家庭娱乐的趋势。     

A RNN-based objective video quality measurement

Technology used to automatically assess video quality plays a significant role in video processing areas. Because of the complexity of video media, there are great limitations to assess video quality with only one factor. We propose a new method using artificial random neural networks （RNNs） with motion evaluation as an estimation of perceived visual distortion. The results are obtained through a nonlinear fitting procedure and well correlated with human perception. Compared with other methods, the proposed method performs more adaptable and accurate predictions.     

职前数学教师MKT现状的调查研究北大核心

1问题提出 过去二十多年来,不断有研究表明,数学教师的知识和技能影响着学生的课堂经历及其数学认知结果,也影响着数学教育改革的实施情况．已有研究表明,中国数学教师拥有牢固的数学基础,对所教数学内容有着深刻的理解,     

随机需求下有产能约束的技术创新策略研究

在随机需求和技术变革的环境下,基于有产能约束的单供应商-单零售商的供应链结构,研究供应商分销价格决策和技术创新策略以及零售商订货决策。建立了三阶段Stackelberg博弈模型,通过逆推方法求得了供应商最优分销价格和技术创新策略以及零售商最优订货量,深入探讨了供应商产能、新技术出现概率以及市场需求期望与波动分别对供应商、零售商和供应链整体利润的影响。结果表明当供应商产能不足时进行技术创新会提高供应商和供应链的利润,但零售商因间接承担供应商技术创新的投资成本而利润下降;当供应商产能过剩时进行技术创新则会降低供应商及供应链的利润,而零售商的利润增加。新技术出现概率增加会提高供应链各成员的利润;提高市场需求期望并减小市场波动对供应商及供应链有利,但可能会降低零售商的利润。     

超宽带及其关键技术

首先介绍了UWB无线通信系统的定义、基本原理以及主要指标,然后详细介绍了UWB的关键技术,最后指出了UWB所面临的挑战。     

A VU-decomposition method for a second-order cone programming problem

A VU-decomposition method for solving a second-order cone problem is presented in this paper. It is first transformed into a nonlinear programming problem. Then, the structure of the Clarke subdifferential corresponding to the penalty function and some results of its VU-decomposition are given. Under a certain condition, a twice continuously differentiable trajectory is computed to produce a second-order expansion of the objective function. A conceptual algorithm for solving this problem with a superlinear convergence rate is given.     

含典型氟-氢邻近与远程耦合的混合物的核磁共振氢谱示例

Two serials of tetrasubstituted benzene compounds containing fluoro group were designed and synthesized. The other three substitutes are sequentially the para, meta, and ortho to fluoro group. The obtained compounds were all mixtures as confirmed by ¹H NMR spectroscopies. The spectra clearly show the proximity and remote interaction between fluorine atom and hydrogen atom. In addition, the two spectra, one showing the overlapping peaks, one not, can be used as the simple and typical example of ¹H NMR spectra of mixtures.     

多码多载波CDMA系统的性能分析

文中提出了一种新的多码多载波CDMA(MC-MC-CDMA)系统,并对此系统在频率选择性衰落信道的性能做了分析.相似于多载波调制,传输的高数据率数据首先进行串-并转换,再对变换后的低数据流用一组正交序列进行扩频调制,然后对各支路的扩频信号分别用L个正交的载波进行调制.MC-MC-CDMA系统中每个用户使用多个正交的码可以实现多数据率的传送并且在时域上进行扩时,满足下一代通信标准的要求.     

Nd:YAG激光治疗内痔的临床疗效及病理观察

我院在1985年11月～1987年3月用光纤传输Nd:YAG激光对内痔进行光凝治疗,计Ⅱ～Ⅲ度脱垂内痔17例,其中3例为花圈痔分2次进行光凝,总共20人次,50个痔核,疗效满意.一、使用仪器和照射方法1.采用上海医用激光仪器厂制造的Nd:YAG激光器,波长1.06μm,输出功率为30～4OW,用光导纤维传输,光纤直径0.6mm,其输出端功率为20～25W;光斑直径0.4cm,照射距离1cm.     

丁二烯－八甲基环四硅氧烷的嵌段共聚合研究 Ⅱ．嵌段共聚物表征及其选择透气性能

用红外光谱、核磁共振氢谱、示差扫描量热法、凝胶色谱法、电子显微镜、Ｘ－射线衍射等现代分析测试手段对聚丁二烯一聚二甲硅氧烷嵌段共聚物，Ｐｏｌｙ（Ｄｄ－ｂ－ＤＭＳ），进行了表征，结果表明Ｐｏｌｙ（Ｂｄ－ｂ－ＤＭＳ）具有嵌段结构和微观相分离形态；研究了Ｐｏｌｙ（Ｂｄ－ｂ－ＤＭＳ）的成膜性及选择透气性，证明其具有较好的富氧性能；考察了铸膜条件、硫化条件对选择透气性的影响；初步讨论了微观结构与选择透气性的相关性．