数字签名技术改进方案研究

分析了采用秘密密钥和公开密钥的数字签名技术的不足,提出了相应的改进方案,从而可实现数字签名的各种功能,最后提出一种更为安全的多方数字签名方案。     

特征信号检测法

本文以信号极点的不变性为基础,构造了一种用于可自设计的主动式系统在强噪声背景下的极微弱信号检测的检测器——特征信号检测器。文章在分析经典检测方法对极弱信号检测存在的问题的基础上,提出了特征信号检测的思想。讨论了该方法的基本原理及仿真实验结果。Monte carlo实验表明,这种特征信号检测器的性能对信噪比不敏感,可以在极低信噪比下检测出微弱信号。     

一种基于混沌的彩色图像空域半脆弱水印算法

为实现对数字产品的版权保护和完整性认证,提出了一种以最低有效位(LSB)替换算法为核心,以彩色图像RGB图层亮度分量为载体的基于混沌二值密钥随机控制的彩色图像空域有意义水印算法.实验结果表明,算法实现简单,实时性好,具有良好的透明性、安全性和确定性,可盲检测,并能够很好地实现版权保护和篡改检测与定位,同时算法对椒盐噪声的去除、裁剪等基本图像操作和位平面去除等恶意攻击具有一定的鲁棒性,因而是一种性能良好的半脆弱水印算法.     

复杂背景条件下的红外图像末制导技术

通过结合目标红外特征,研究了空-空弹在复杂背景条件下的目标红外成像末制导的技术原理和实施途径。对复杂地背景的辐射特征和主要空中攻击目标军用喷气战机的目标红外辐射源类型作了分析,研究了红外目标特征的提取方法和算法。     

基于PGP的动态连接库构成的安全认证系统

探讨PGP系统的主要功能以及实际使用过程中存在的问题,提出了一种新方案,即利用PGP提供的动态连接库以及优盘的特点的解决方案.根据该方案讨论的相关算法和流程,研制出电子文档的加密与认证系统.     

Systems composed of two types of nonidentical and dependent components

A coherent system of order n that consists two different types of dependent components is considered. The lifetimes of the components in each group are assumed to follow an exchangeable joint distribution, and the two random vectors, which represent the lifetimes of the components in each group are also assumed to be dependent. Under this particular form of dependence, all components are assumed to be dependent but they are categorized with respect to their reliability functions. Mixture representation is obtained for the survival function of the system's lifetime. Mixture representations are also obtained for the series and parallel systems consisting of disjoint modules such that all components of Type I are involved in one module (subsystem) and all components of Type II are placed in the other module. The theoretical results are illustrated with examples. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 388–394, 2015     

直觉模糊物元及其在权重信息未知多属性群决策中的应用

针对传统物元分析理论无法应用于决策信息为直觉模糊数的多属性决策问题,提出直觉模糊物元分析模型以及用相对相似度代替传统方法中的关联函数来解决直觉模糊物元分析问题,进而完整阐述了直觉模糊物元多属性决策的方法步骤,并通过实例验证了该方法的有效性。特别是针对权重信息未知这一类较为复杂的多属性群决策问题,采用投影法和直觉模糊熵确定权重信息,并运用直觉模糊物元多属性决策方法进行了实例分析,证明了方法的实用性,为直觉模糊多属性群决策提供了一种新的思路。     

INTRODUCTION: THE DYNAMICS OF NUCLEAR DISARMAMENT

Decisionmaking processes leading to the acquisition of nuclear weapons by democratic states have served as the basis for theories about nuclear proliferation. In contrast, less is known about how a totalitarian regime responds to immense external pressure to abolish unconventional weapons it considers crucial for its security and survival. This article will analyze how we can explain Iraq's behavior after the passing of Resolution 1441 and during the United Nations inspections in 2002–2003.     

针对DSA滑动窗口算法实现的指令Cache计时攻击

在现有的针对RSA等公钥密码的指令Cache计时攻击的研究基础上,提出了一套可行的针对DSA的指令Cache计时攻击方法,并对计时信息采集、识别、密钥恢复等环节进行了研究,给出了一种随机密钥恢复算法。搭建了攻击实验平台,利用编写的间谍程序对滑动窗口算法实现的DSA签名进行了实际攻击,验证了指令Cache计时攻击方法是可行、有效的．     

Coordinating Covert Action: The Case of the Yemen Civil War and the South Arabian Insurgency

Focusing on British involvement in the 1960s Yemen Civil War, this article examines the centralised mechanisms developed in Whitehall to coordinate covert action interdepartmentally. It therefore sheds new light on London's security and intelligence machine and its input into clandestine operations. Drawing on recently declassified documents and interviews, it uncovers various important but secretive actors, which have been overlooked or misunderstood in the existing literature, and outlines their functions in the most detail yet available. In doing so, it considers how these bodies evolved in relation to competing threat assessments of the local situation and the impact they had on Britain's covert intervention in the theatre. This article assesses the utility of the system and argues that it provided an effective means to ensure that any covert action sanctioned was properly scrutinised so as to reduce risks and best meet national interests.