一个动态门限的基于属性签密方案

签密能同时实现加密与签名,并且代价小于传统的先签名再加密。该文在Li等人(2010)签名方案的基础上提出了一个动态门限的基于属性签密方案,除具有一般签密方案的保密性和认证性外,还同时具有签密者属性隐私安全性和多接收者特性。在随机预言机模型下,利用判定双线性Diffie-Hellman (DBDH)问题和计算Diffie- Hellman (CDH)问题的困难性,证明了该方案满足在适应性选择密文攻击下的不可区分性及适应性选择消息下的不可伪造性。     

Survey on the causal consistency of data

Causal consistency is one of the important projects to ensure data consistency in distributed storage.The current research focuses on causal consistency including optimization of clock method,design of the protocol and the optimization of operation transaction sequence.In the actual cloud environment,in addition to clock skew and query amplification,there are also insecure factors such as Trojans and untrusted third parties,which will destroy the causal consistency metadata stored by users,and the consistency of user’s operating results,even affect the availability of the storage environment.From the perspective of performance improvement and security in distributed storage,the clock synchronization,data replications,analysis and design of server protocol,related research progress of the serialization of operational affairs were introduced combined with consensus mechanisms such as blockchain.At the same time,their principlest,advantages,limitations,and different utilities in terms of security constraints were discussed,and then the future development trends and follow-up research directions were point out at last,which would provide a reference and help for the research in this field.     

地面模拟系统DBF接收机设计

在卫星的地面测试中,地面模拟系统发送遥控遥测信号并接收卫星的返回信号,将其下变频到中频进行解调,从而获取卫星工作状态和运行环境,模拟其在轨运行工作情况。针对目前采用有源相控阵天线技术的卫星地面测试,本文设计实现了一种DBF体制的地面模拟系统接收机,该接收机采用超外差式二次变频设计,具有高增益、低噪声系数、低群时延波动、良好的通道间幅相一致性和稳定性,同时集成度高,体积小,可制造性强,能够充分的满足采用有源相控阵技术的卫星地面测试要求。     

量测提升卡尔曼滤波

滤波器设计是系统辨识和状态估计的重要基础.卡尔曼滤波通过状态预测和量测更新的实现框架,在最小方差准则下实现对目标状态的最优估计,但在单传感器量测环境中其滤波精度易受量测噪声随机性的影响.本文提出一种基于量测提升策略的卡尔曼滤波算法实现框架,新方法依据当前时刻量测和量测噪声先验统计信息构建虚拟量测,并通过对虚拟量测采样以及融合提升系统量测信息可靠性,进而改善状态估计精度.同时,针对算法在工程应用中实时性、准确性以及鲁棒性等需求,设计了分布式加权融合和集中式一致性融合的两种实现结构.理论分析和仿真实验结果验证了算法的可行性和有效性.     

基于预排序和上取整函数的AHP判断矩阵生成算法

 对于层次分析法中不满足一致性要求的判断矩阵,提出了一种新的生成算法.此算法首先对目标因素集进行预排序生成初始判断矩阵,由上取整函数生成比较矩阵,然后由初始判断矩阵和比较矩阵构造相对误差矩阵,并在相对误差矩阵和矩阵相异度的控制下逐步调整初始判断矩阵,最后生成满足一致性要求和矩阵相异度最小的目标判断矩阵.仿真结果证实了所提出方法的可行性和有效性.     

激光图像可匹配性评价模型

为了解决实际应用中激光实时图像的可匹配性预判的问题,通过优化的主成分分析法对常用的6个激光图像评价参数进行了筛选,最终得了到能够很好评价图像质量的四个关键参数,并应用这四个参数建立了激光强度图像可匹配性评价模型。从验证的结果看,该评价模型的评价结果与激光图像的匹配率具有很好的一致性,这说明了该模型在实际应用中对激光图像的可匹配性的预估具有一定的参考价值。     

PKI签发机制相关标准一致性验证研究

分析了PKI签发机制相关标准存在的一致性问题,设计和实现了基于信息安全关键标准验证平台的仿真程序模块,并对证书格式、证书编码和证书更新时的有效性开展了标准一致性仿真验证。     

粗颗粒煤水混合物的稠度和流变特性的研究

燃煤增压流化床的燃料制备与输送系统往往需采用气力输送方法送入加压罐后再送入炉内，系统复杂．采用煤水混合燃料泵送技术则可解决上述困难．提出了用塌落度测定方法判断０～６ｍｍ粗颗粒煤水混合物的可泵性，并选择适于泵送的较佳颗粒级配．建立了泵送与管道输送试验台进行粗颗粒徐州煤水混合物的流变特性试验，所得的泵送流变试验数据处理后的模型，可用于商用粗颗粒煤水混合物输送系统的设计计算．     

Parameter identifiability with Kullback–Leibler information divergence criterion

We study the problem of parameter identifiability with Kullback–Leibler information divergence (KLID) criterion. The KLID‐identifiability is defined, which can be related to many other concepts of identifiability, such as the identifiability with Fisher's information matrix criterion, identifiability with least‐squares criterion, and identifiability with spectral density criterion. We also establish a simple check criterion for the Gaussian process and derive an upper bound for the minimal identifiable horizon of Markov process. Furthermore, we define the asymptotic KLID‐identifiability and prove that, under certain constraints, the KLID‐identifiability will be a sufficient or necessary condition for the asymptotic KLID‐identifiability. The consistency problems of several parameter estimation methods are also discussed. Copyright © 2008 John Wiley & Sons, Ltd.