布尔电路上保护隐私集合并集运算的研究与实现

隐私保护技术是当前信息安全领域的研究热点。然而,现阶段集合并集运算中的隐私保护技术侧重理论研究,在实验模型的开发上较为欠缺。针对该问题,该文首先设计了保护隐私的集合合并运算电路、去重电路和混淆电路,并应用YAO氏通用混淆电路估值技术提出了一种布尔电路上保护隐私的集合并集协议。然后,该文使用模拟器视图仿真法证明了协议的安全性。最后,基于MightBeEvil中的YAO氏混淆电路估值框架,开发了该文理论方案对应的实验模型。实验结果表明,在安全计算稀疏集合的并集时,所提算法效率优于当前布尔电路上的其他算法。     

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国外输气干线的增压,都以燃气轮机作压缩机的动力。我国自50年代起生产了一批样机,主要用于发电。本文提出,在国内即将引进生产新型燃气轮机时,应考虑解决适用于干线增压的技术配套等问题。     

Effective identification of dominant fully absorbing sets for Raptor-like LDPC codes

The error-rate floor of low-density parity-check (LDPC) codes is attributed to the trapping sets of their Tanner graphs. Among them, fully absorbing sets dominantly affect the error-rate performance, especially for short blocklengths. Efficient methods to identify the dominant trapping sets of LDPC codes were thoroughly researched as exhaustively searching them is NP-hard. However, the existing methods are ineffective for Raptor-like LDPC codes, which have many types of trapping sets. An effective method to identify dominant fully absorbing sets of Raptor-like LDPC codes is proposed. The search space of the proposed algorithm is optimized into the Tanner subgraphs of the codes to afford time-efficiency and search-effectiveness. For 5G New Radio (NR) base graph (BG) 2 LDPC codes for short blocklengths, the proposed algorithm finds more dominant fully absorbing sets within one seventh of the computation time of the existing search algorithm, and its search-effectiveness is verified using importance sampling. The proposed method is also applied to 5G NR BG1 LDPC code and Advanced Television Systems Committee 3.0 type A LDPC code for large blocklengths.     

无线网络中基于最高向量权独立集的分群算法

ad hoc 网络是多跳无线网络,网络节点通信不依赖于预先架设的固定设施,这种动态网络的重要特点是寻找好的路由算法,基于群的算法是最有效和可伸缩的.然而,由于高度动态拓扑且缺少固定架构,系统重构经常是不可避免的,因此,尽可能长时间使拓扑稳定是至关重要的.极大独立集(MWIS)是一个分群算法,用于将整个网络划分为群,每个群选举一个群首.基于MWIS,提出了最高向量权独立集(HVWIS)算法.首先,每一节点被分配一个向量权,其动机是要考虑相邻节点的多个因素;其次,算法使用了模糊决策模型.这样,群首形成了一个最高向量权独立集,确定了其拓扑和其稳定性.本文证明了HVWIS 算法的正确性并分析了其时间复杂度.     

一种改进的进程调度算法在机顶盒上的设计与实现

调度算法对操作系统中的实时性起着关键的作用.就此问题,深入分析了基于最小优裕度算法的内核进程调度算法,为更好地满足Linux系统对嵌入式系统实时可靠性的要求,对现有的LSF调度策略进行分析,指出LSF算法调度算法的不足.为了改进LSF算法的颠簸现象,基于抢占阈值的思想,提出适用于LSF算法的抢占阈值分配方法,动态地给每...     

Distributed Construction of Connected Dominating Set in Wireless Ad Hoc Networks

Connected dominating set (CDS) has been proposed as virtual backbone or spine of wireless ad hoc networks. Three distributed approximation algorithms have been proposed in the literature for minimum CDS. In this paper, we first reinvestigate their performances. None of these algorithms have constant approximation factors. Thus these algorithms cannot guarantee to generate a CDS of small size. Their message complexities can be as high as O(n ²), and their time complexities may also be as large as O(n ²) and O(n ³). We then present our own distributed algorithm that outperforms the existing algorithms. This algorithm has an approximation factor of at most 8, O(n) time complexity and O(nlogn) message complexity. By establishing the (nlogn) lower bound on the message complexity of any distributed algorithm for nontrivial CDS, our algorithm is thus message-optimal.     

基于正交矩阵构造非周期组间互补序列集

基于正交矩阵,该文提出一类非周期组间互补序列集的构造法。构造的非周期组间互补序列集的零相关区长度可灵活设定,且参数达到了理论界限。通过选取二元或多相正交矩阵,可以得到二元或多相非周期组间互补序列集。构造的组间互补序列可以用于同步和非同步码分多址通信系统。     

基于业务等级的波长分配算法

本文主要研究在WDM全光通信网中,将业务等级约定(SLA)和路由波长分配(RWA)问题结合在一起考虑,根据实际网络情况,确保高等级业务得到更好的服务。本文从不同的角度考虑,提出了两种算法,并对其进行了仿真比较和分析。     

一种新型DSP指令结构及数据通道

针对可以处理不同位宽数据的DSP结构,提出了一种提高指令编码密度的方法,使设计的DSP指令减少了32条。另外提出了两种能同时实现16bit乘法累加运算和32bit乘法累加运算的数据通道结构。对这两种数据通道都用Verilog语言进行了模拟仿真。     

统计指标离散化方法及应用

连续数据离散化能够提高数据挖掘算法的分类能力．文中提出一种基于统计指标的连续属性离散化方法,凭借相关系数衡量类与属性间的关联度,获取最优区间列表．引入变精度粗糙集模型,有效地控制数据由离散化导致的信息丢失．该方法在声纳传感器数据识别以及其它领域上进行了应用．实验结果表明,该方法在J48决策树上有很好的分类能力．