AFC系统中多串口技术的实现

本文主要介绍了AFC系统车站级设备，通过多串口技术实现主机对多个子设备进行控制的硬件及软件主要过程。     

无随机预言机的广义指定验证者签名方案

现有的广义指定验证者签名方案的安全性大都是在随机预言机模型下证明的,但是在该模型下的可证安全并不意味着在现实中是安全的.基于Zhang等人提出的无随机预言机模型下的短签名方案,提出了一个在标准模型下可证安全的广义指定验证者签名方案,其强不可伪造性基于k＋1平方根假设和指数知识假设,证明了提出方案在选择公钥和选择消息攻击下是无条件不可传递的.方案的签名长度为1366 bits,比现有方案的签名长度要短.     

6 级海况下的某型发射平台回转俯仰耦合动力学研究

针对某型靶弹通用发射平台,开展该平台在摇摆载荷作用下的回转和俯仰耦合动力学特性的研究。将原 有陆基发射平台的回转俯仰耦合动力学扩展到海上平台,分析其在某型船6 级海况下的运动特性和回转俯仰耦合动 力学特性;将6 级海况等效为沿3 坐标系的等效加速度,基于ADAMS 对该海况下的靶弹通用发射平台进行仿真分 析。仿真结果表明,该研究对复杂海况下发射平台的结构强度和运动规律均具有一定的指导意义。     

On Universal Telecommunication Service and West China Development

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多核软件的几个关键问题及其研究进展

 提高应用程序开发产能同时获得并行性能收益是多核大众化并行计算研究的核心目标.采用应用驱动和自顶向下的研究思想着重综述了影响该目标的三个关键问题.首先,对当前的多核应用驱动研究做了比较,并对多核应用研究现状做了综述.其次,对当前的多核编程模型在产能编程和性能使能编程方面的研究思想做了比较研究.然后,综述了多核算法以及多核计算模型的研究现状.最后分析了多核软件未来的研究问题.     

Arthur Conan Doyle and psychic photographs

Abstract

The issue of Punch for 12 May 1926 featured a cartoon which depicted an elderly and oversized Arthur Conan Doyle sitting on a stool (see figure 1). Clouds are gathered around his uplifted, preoccupied head. Holding a chain which shackles Doyle's legs is a miniature Sherlock Holmes, brooding and thoughtful. The cartoon's immediate context is satirical: Doyle's warm reception of the Cottingley Fairy photographs, then a matter of ongoing notoriety due to the publication of his The Coming of the Fairies in 1922, had prompted a degree of ridicule. In 1920 he had become involved in an investigation of what purported to be photographs of actual fairies taken by two teenage girls. The matter which commenced as an investigation had, by 1928, with the publication of the study's second edition, developed into a whole-hearted endorsement of the photographs. For Doyle and his colleague, the theosophist Edward Gardner, this event was the ultimate proof that fairies actually existed. Nor was the intervention Doyle's only encounter with paranormal photography. A committed spiritualist by the 1920s, Doyle had previously championed the cause of spirit photography, a process where supposed materializations of the dead appeared in photographs. For the spiritualists, this possibility was an important concept, as it endorsed their central tenet: that the living could communicate with the dead. Relatedly, Doyle's The Case for Spirit Photography (1923) defended William Hope, who had been accused of using fraudulent methods to attain his materializations.     

抽水蓄能电站过渡过程仿真自动建模及通用程序

本文在改进文献中数学模型及有关连接方式的前提下引入结构形式参数，工况标识参数及部件动态计算模块化等，解决了按仿真对象及仿真工况的自动建模问题，编制的程序用于多个具有不同引水系统和参数的电站过渡过程仿真计算，证明有较强的通用性，灵活性和实用性。     

Reliability evaluation for linear consecutively‐connected systems with multistate elements and retransmission delays

A linear consecutively‐connected system consists of N linear ordered positions at which statistically‐independent multistate elements with different characteristics are allocated. Each element can provide propagation of a signal it receives from the previous positions to the next few positions. Each element can have different states determined by a number of adjacent nodes receiving the signal directly from this element. The signal retransmission process is associated with delays. The system fails if the signal generated at the first position (source) cannot reach the Nth position (receiver) within a specified time. An algorithm based on the universal generating function method is presented in this paper for determination of reliability of the linear consecutively‐connected system with delays. Copyright © 2001 John Wiley & Sons, Ltd.     

卫星双向时间频率比对软件接收技术研究

研究了一种基于软件无线电接收机(SDR)的卫星双向时间频率传递技术(TWSTFT),该技术能明显降低卫星双向比对中的测量噪声,与基于卫星时间调制解调器(SATRE)的TWSTFT相比,SDR TWSTFT表现出更优良的性能。在基于AM22通信卫星的亚洲-欧洲卫星双向比对链路中,NIM与俄罗斯计量院(SU)之间的SDR TWSTFT结果相对于SATRE TWSTFT得到明显改善,增益因子的平均值为2.0;同时,NIM-SU SDR链路也是全球第一条周日变化误差得到明显改善的长基线洲际SDR TWSTFT链路。分析了基于ABS-2A通信卫星的SDR TWSTFT和SATRE TWSTFT时间稳定度计算结果,结果表明SDR TWSTFT对短期链路噪声的抑制效果更为显著。     

基于用户行为智能观测的导视系统设计

目的运用传感器与机器学习算法对不同文化背景的老年用户在地铁站内的寻路行为特征进行研究,进而为提高地铁站内导视系统的通用化设计水平提供数量化与科学化决策支持。方法应用Zig Bee人体智能传感器模块,以异地访京和本地老年人为被试进行了高频度追踪数据采集试验,分析其在地铁站内的寻路行为与差异。结果构建了基于Zig Bee智能模块的行为观测研究方法。结论为老年人提供快捷且直观的导视信息,能够节约寻路过程中所消耗的脑力与体力,提高寻路体验兼顾社会公正。