流媒体技术及其教育应用

介绍了流媒体出现的背景及其技术原理,从流媒体独特的特征着手,对其在教育教学中,尤其是在远程教育中的应用进行了详尽的阐述,对其未来的发展方向提出建议.     

特大型城市PHS网络的网优方法

文章针对特大型城市PHS网络的网络优化工作,提出了整体网络优化方法,即:既考虑无线网络优化,也考虑交换网络优化.优化步骤为:先进行数据收集和分析,然后开展核心交换网优化,调整集成基站控制器(iCSC)、寻呼区(PA),再优化基站覆盖,增强基站同步能力.文章还提出了通过特定的补充业务和增值业务弥补网络覆盖的不足,提升用户满意度和网络指标的方法.     

设计余弦调制QMF组的一种新方法

通过适当矩阵变换，本文首先将精确重建余弦调制正交镜像滤波器组的设计转化为一种带约束的非线性优化问题，它是一种带二次型约束的最小二乘（ＱＣＬＳ）优化问题，然后，我们提出了一种变参量的罚函数方法来有效求解该类ＱＣＬＳ优化问题，通过直接采用原型滤波器系数为优化变量，我们构造了一个特殊的凸函数作优化代价函数，故可获得该问题的全局最小点，最后，采用本文提出的设计方法进行了一个具体实例设计，结果表明我们的方法     

基于RTP的流媒体传输系统的设计与实现

旨在解决流媒体实时传输的效率和系统的可拓展性问题。介绍了流媒体传输的基本协议RTP,并针对实时传输过程中的特殊要求,设计出了一种流媒体传输的结构模型,在流量控制、组包算法和缓存管理等方面进行研究,给出了详细的实现过程。     

Crosstalk-aware multi-bit flip-flop generation for power optimization

Applying multi-bit flip-flops (MBFFs) for clock power reduction in modern nanometer ICs has been becoming a promising lower-power design technique. Many previous works tried to utilize as more MBFFs with larger number of bits as possible to gain more clock power saving. However, an MBFF with larger number of bits may lead to serious crosstalk due to the close interconnecting wires belonging to different signal nets which are connected to the same MBFF. This paper analyzes, evaluates, and compares the relationship between power consumption and crosstalk when applying MBFFs with different numbers of bits. To solve the addressed problem, a novel crosstalk-aware power optimization approach is further proposed to optimize power consumption while satisfying the crosstalk constraint. Experimental results show that the proposed approach is very effective in crosstalk avoidance when applying MBFFs for power optimization.     

从广播网络化到网络化广播的发展探讨

本文主要针对广播的发展状况,探讨广播从广播网络化到网络化广播的一些发展变化.主要介绍了如何会产生这些变化,以及网络化广播的特点和优势.使人们认识到网络与广播之间密不可分的关系,以及今后网络化广播发展的方向.     

广电企业业务流程的分析和优化

介绍了广电网络业务流程的整体结构,对目前广电业务流程的评价指标体系进行了分析,提出了以流程时间、流程速率、工作队列等组成广电网络业务流程的实例--业务流程的评价指标,以及基于Little法则的广电网络业务流程评价指标体系曲简化方法.研究了采用时间Petri网建模对企业业务流程分析的方法和分析优化步骤,并针对广电网络业务流程的具体业务流程给出的实际案例进行了分析.     

一种降低DMT系统发送信号峰值的非线性映射方法

针对DMT ADSL（DMT线路码非对称数字用户环路）传输系统发送信号幅值尖峰问题。本文提出了一种降低发送信号最大峰值同时又不损失系统 传送信息的非线性映射方法。通过最优化方法合理地设计一组可逆映射器,该方法比目前ADSL系统的硬限幅方法能较大幅度地压缩系统的动态范围或在相同的动态范围下获得更好的传输性能。     

Global optimization approach to nonlinear optimal control

To determine the optimum in nonlinear optimal control problems, it is proposed to convert the continuous problems into a form suitable for nonlinear programming (NLP). Since the resulting finite-dimensional NLP problems can present multiple local optima, a global optimization approach is developed where random starting conditions are improved by using special line searches. The efficiency, speed, and reliability of the proposed approach is examined by using two examples.Financial support from the Natural Science and Engineering Research Council under Grant A-3515 as well as an Ontario Graduate Scholarship are gratefully acknowledged. All the computations were done with the facilities of the University of Toronto Computer Centre and the Ontario Centre for Large Scale Computations.     

Multicolor particle systems with large threshold and range

In this paper we consider the Greenberg-Hastings and cyclic color models. These models exhibit (at least) three different types of behavior. Depending on the number of colors and the size of two parameters called the threshold and range, the Greenberg-Hastings model either dies out, or has equilibria that consist of debris or fire fronts. The phase diagram for the cyclic color models is more complicated. The main result of this paper, Theorem 1, proves that the debris phase exists for both systems.