基于RTP协议H．264视频流传输QoS保证的研究

提出一个Linux环境下基于RTP/RTCP的H.264视频流传输的方案,在Linux中调用V4L(VideofourLinux)的API函数采集视频流,经X264压缩,RTP/RTCP协议打包进行传输。并通过RTCP的RR(接收方报告)包反馈信息和吞吐量公式来计算近似带宽,以起始帧量化参数start-qp为视频编码的调节参数,由近似带宽来控制视频编码的参数调整,达到控制输出码率的目的,实现对视频传输的QoS(QualityofService)保证。     

三坐标雷达目标真实高度估计算法研究

在目标跟踪领域,通过三坐标雷达的测量值(斜距、仰角及方位角)来估算目标的真实高度一直是个难点。目前主要有两类处理方法:坐标转换法和等效地球半径法。前者把与雷达天线相关的三坐标测量值转换到大地坐标系统来计算目标高度;后者充分考虑地球曲率以及大气折射的特性,通过增加地球半径来估算目标的高度。最后对上述的两类方法进行总结、比较与分析。     

一种基于SOAP安全的网络中心发布/订阅机制

针对网络中心发布/订阅系统异步、松散耦合和多对多通信等特点,采用了SOAP消息传递机制对信息进行了封装,从而屏蔽了信息的异构性。考虑到信息传输的可靠性,采用XML-Encryption机制构造SOAP消息,为消息交换和数据传输提供一种安全的保证。实际应用表明该系统在网络中心战中有较好的应用前景。     

聚硅氧烷先驱体转化制备2D Cf/Si-O-C材料

以二维碳纤维布和廉价的聚硅氧烷为原料,采用先驱体转化工艺制备2D Cf/Si-O-C材料,对其力学性能进行了考察,并与以聚碳硅烷为先驱体制备的2D Cf/SiC材料在价格和性能方面进行了对比。实验表明,2D Cf/Si-O-C材料力学性能较2D Cf/SiC材料有所下降,但成本大大降低。2D Cf/Si-O-C材料弯曲强度达到157.9 MPa,断裂韧性达到8.4MPa.m1/2,剪切强度达到23.4MPa,并且在1400℃下能较好保持材料的力学性能。     

Emergency transshipment in decentralized dealer networks: When to send and accept transshipment requests

While there has been significant previous literature on inventory transshipment, most research has focused on the dealers' demand filling decision (when to fill transshipment requests from other dealers), ignoring the requesting decision (when to send transshipment requests to other dealers). In this paper we develop optimal inventory transshipment policies that incorporate both types of decisions. We consider a decentralized system in which the dealers are independent of the manufacturer and of each other. We first study a network consisting of a very large number of dealers. We prove that the optimal inventory and transshipment decisions for an individual dealer are controlled by threshold rationing and requesting levels. Then, in order to study the impact of transshipment among independent dealers in a smaller dealer network, we consider a decentralized two‐dealer network and use a game theoretic approach to characterize the equilibrium inventory strategies of the individual dealers. An extensive numerical study highlights the impact of the requesting decision on the dealers' equilibrium behavior in a decentralized setting. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

基于实际案例的导弹装备战斗损伤评估

指出了基于实际案例的通用导弹装备战斗损伤评估内容及特点,提出了战斗损伤评估的量化标准,定义了战损率的概念;采用向量夹角余弦方法综合出了导弹装备各级组件的战损率及车辆的战损量化值,并通过实例证明了该方法具有所需信息量小、主客观综合性强、评估方法易于仿真实现等优点.     

PMSM空间矢量控制在坦克全电炮控中的应用

介绍了数字交流全电式坦克炮控系统的设计,针对基于DSP(数字信号处理器)的永磁同步电动机(PMSM)电压空间矢量算法的特点,研究出了优化控制的新算法,减少了计算量,提高了系统的性能.试验结果表明系统具有良好的动静态性能,能显著地提高炮控系统的各项战技指标.     

大学英语文化教学初探

大学英语教学在贯彻提高大学生英语知识水平的同时,必须把外语教学与文化教学紧密地结合起来。语言是文化的载体,又是文化的重要组成部分,文化对语言的产生和发展起着重要作用。大学英语教学要有目的、有计划地实施文化教学,通过掌握英语国家的历史背景、文化内涵来指导外语学习,培养学生对西方文化的了解,为今后顺利使用外语和胜任跨文化交际打好基础。     

涉外型院校实施体育“双语教学”的可行性研究

在社会飞速发展的时代,经济的进步促使知识的日新月异,导致教学模式的不断创新。伴随着我国加入WTO,双语教学应运而生.在体育教学中运用双语教学,是体育教学模式的大胆尝试和教学手段的创新.涉外型院校具有实施体育双语教学得天独厚的条件,双语教学的实施具有重要意义,并有可行性。     

Property distribution and configurations of sovereign states: A rational economic model

A nation's wealth is both an object of conquest to covetous aggressors and a resource to its owners for self defense. To maintain autonomy every country must mount a defense which either makes its capture (1) more expensive than any aggressor can afford, or (2) more expensive than it is worth to aggressors. Whether this condition can be satisfied for all countries simultaneously depends as shown in this paper on relative efficacy of military offense versus defense, the aggregate of wealth among nations and its distribution, and the benefits a conqueror may obtain from conquest, including the duration of these benefits. The paper shows how these factors fit together to determine the sustainability and stability of the international distribution of property as embodied in the configuration of sovereign states.