非静止轨道卫星系统考虑通信中断的服务质量分析

基于Globalstar和Odyssey两个Walker delta星座,建立星间链路网络,重点分析网络中的不同轨道间星间链的动态特性,特别是与星上跟瞄系统密切相关的俯仰角、方位角和链路长度变化,为卫星网络路由提供依据.对传统的卫星路由策略作了改进,利用卫星系统的冗余覆盖的特性,选择不同策略下的最优路径.针对用户不能忍受通信中断的情况,提出考虑消除中断的路由策略,进行服务质量的分析比较.同时也比较在消除中断的路由策略下,LEO同MEO网络差异之处.消除通信中断是以其它QoS性能下降为代价.     

美军战术数据链格式化消息标准的发展

首先介绍了战术数据链及格式化消息的概念、特点及消息体系的层次结构,在此基础上对美军战术数据链格式化消息标准的发展历程及为满足信息化战争的需要而不断完善和发展的新趋势进行了详细分析,最后对我国战术数据链格式化消息标准的发展提出了建议。     

一种基于DS-FFH/MSK调制的数据链抗干扰性能分析

提出了DS-FFH/MSK调制方式的一种实现方案,并在多种干扰环境下,从信源误比特率的角度对基于该实现方案的Link16战术数据链的抗干扰性能进行了系统分析,推导了几种不同干扰条件下数据链的误比特率表达式,并给出了计算机仿真结果.     

虚拟企业伙伴选择方法的研究

选择正确的合作伙伴是虚拟企业组建的关键步骤之一,也是虚拟企业成功运作的首要前提。针对某一具体案例,从目前虚拟企业伙伴选择的几种典型方法入手,运用系统研究方法,对各方法的具体思路作一总结,并提出了各方法的适用范围、优势与弊端,同时,找出了它们之间的差异所在。     

关于用链条索具吊装螺纹钢的可行性分析研究

在港口企业，常用钢丝绳吊具捆绑螺纹钢来对其进行装卸作业。由于钢丝绳与螺纹钢间的摩擦力非常大且螺纹对钢丝绳有剪切力使得钢丝绳吊具的磨损非常大，用于钢丝绳更换的生产成本较高。文中对该方法进行改进，采用链条方式捆绑螺纹钢，降低了两者间的相对磨损，通过与原方法的经济性比较及实际效果的分析，证明该方法更为可靠和经济。     

基于模式识别的短波ALE系统8FSK信号解调

根据美军标MIL-STD-188-141A的规定，8FSK信号的解调是短波自动链路建立(ALE)系统的一项关键技术。通过把图像分割和聚类分析方法应用于8FSK信号的频谱分析，提出了基于模式识别的解调算法。测试结果表明，该算法对白噪声不敏感。     

基于PCI/PCIX总线实现宽带数据高速传输

介绍了传统宽带数传的实现方式,分析了用FPGA实现PCI/PCIX总线的优点,实现了基 于PCI/PCIX总线IP核的宽带高速数传,IP核在66 M/64 bit工作方式,以突发传输模式 下,速度达到了420 Mbyte/s,满足了宽带数据高速传输的要求。     

The role of fundamental motivations in willingness-to-pay online

This study aims to determine whether an understanding of chronic fundamental consumer motivations can help determine the mechanisms of willingness-to-pay for products online. To do so, it employs a simulated buying task on a fictional e-commerce site for a consumer product (branded either as a “new arrival” or a “classic”) to investigate the effects of two fundamental motivations (mate acquisition vs. self-protection) on willingness-to-pay for the product online. The primary focus of the paper to investigate the capacity of mate acquisition and self-protection motives to moderate the relationship between attitude toward the product and willingness-to-pay, as well as, the effects of the motives on willingness-to-pay are considered. Through regression and interaction effect analyses, it is shown that chronic fundamental motivation for mate acquisition is directly correlated with an increased willingness-to-pay for both product types, and it moderates the relationship between attitude toward a product and willingness-to-pay. Self-protection motivation increases willingness-to-pay for classic products but not new arrivals. By offering a rare look at chronic fundamental motivation in the consumer context and potentially being the first investigation of the moderating effects of fundamental motivations, the results mostly support the notion of predictable motivation induced behavioral tendencies.     

Public good agreements under the weakest‐link technology

We analyze the formation of public good agreements under the weakest‐link technology. Whereas policy coordination is not necessary for symmetric players, it matters for asymmetric players; however, this fails in the absence of transfers. By contrast, with a transfer scheme, asymmetry may be an asset for cooperation. We characterize various types and degrees of asymmetry and relate them to the stability of self‐enforcing agreements. Asymmetric distributions of autarky public good provision levels (also representing asymmetric interests in cooperation) that are positively skewed tend to be conducive to the stability of agreements. We show that under such conditions, even a coalition including all players can be stable. However, asymmetries that foster stability (instability) tend to be associated with low (high) gains from cooperation.     

大跨度天基数据链的TDD时隙调度分析与优化

针对天基数据链系统卫星间的传播时延较大且节点间距离变化较大等特点，提出了一种提高时频资源利用率、提升系统容量、减小时延的方法。在时分多址与空分多址相结合的接入方式下，进行了时隙调度的分析与优化，利用卫星星座的空间复用与大跨度传播时延特性，采用时隙编排、收发状态调整、帧格式优化等手段，将信道利用率和系统容量提升了1倍，将卫星节点在某一方向获得服务的平均等待时间缩短为原来的1/4，提高了天基数据链系统的服务质量。