校园网投票安全隐患及解决措施探讨

安全性问题一直是网络投票的隐患,也是令开发者比较头痛的事情.该文通过开发校第四届、第五届十佳学子的投票网站,结合实际工作中遇到的问题,谈谈网络投票的安全性问题,并提出了实际的解决措施,最后给出了后续思考.     

基于虚拟基线的干涉仪测向改进方法

复杂电磁环境下对复杂电磁信号进行测向是电子信息侦测的必要手段。并针对传统数字相位干涉仪解模糊和天线布设等技术问题,根据干涉仪测向基本原理,提出了一种基于虚拟基线的相位干涉仪方法,并利用大数判决准则对干涉仪测向估计方法进行了改进,改善和提升了测向性能。通过理论分析与仿真验证了该干涉仪设计与改进方法的有效性、可行的,同时该方法有利于工程实时实现,对实际工程应用有重要的参考意义,尤其是多长基线和多种天线阵形式的干涉仪系统。     

基于量子行走公钥加密的电子投票方案

为了解决当前部分量子投票协议中大量使用制备复杂的纠缠资源及操作困难的纠缠态测量,从而导致可实现性差的问题,文章基于量子行走公钥加密设计电子投票方案,量子行走可以在粒子之间产生任意形式的纠缠,并避免纠缠态测量。初始时仅需制备单粒子,若干步量子行走后再对其实施单粒子测量,即可以实现所提方案。文章中使用的量子行走技术已在多种系统上实现,安全性分析表明,该方案可以实现信息论安全,当前技术下可行且安全。文章方案仅使用1个粒子表示n位投票信息,效率高于现有方案。     

影响最大化问题中基于K-truss的投票改进算法

在社交网络的影响最大化（IM）问题中,近似算法通过大量的Monte-Carlo模拟计算节点集的影响范围,导致时间复杂度提高,而多数启发式算法在具有不同拓扑结构的图上存在稳定性较差的问题。提出基于K-truss的改进投票算法TrussVote。在投票阶段,通过引入K-truss的相关理论及算法定义节点的有效投票能力,用于表示节点对其不同邻居的投票倾向,同时在计算得票分数时考虑边的传播概率,提高解决IM问题的效率。在每轮投票结束后,将得票分数最高的节点选为种子节点。在更新阶段,结合节点间的相似性指标定义衰减因子,以有效区分邻居节点投票能力的弱化程度。此外,基于IC模型下的原始传播结果,提出传播差异作为传播范围的等价分析指标。在不同规模真实网络数据集上的实验结果表明,相比RNR、VoteRank++等算法,该算法不仅能有效降低时间复杂度,而且可在最短的时间内感染更多的节点,具有广泛的影响范围。     

基于暂态高频分量的故障投票选线方法

针对现有小电流系统单相接地故障暂态选线特征信息提取、处理以及选线精度的问题,文中对故障进行暂态特征分析,发现各线路暂态零序电流中高频分量具有明显差异。据此结果,文中提出了一种基于暂态零序电流高频分量的波形相似性的投票选线方法。结合VMD算法和巴氏距离算法,分解各条线路的零序电流,得出暂态高频分量,进而求得各线路间暂态高频分量的巴氏系数。然后对系数矩阵采用初步投票与k值检验的方法进行投票,从而判断出故障线路。不同故障情况下的仿真结果表明该方法简单可靠,选线精度及可信度高,具有广泛的适用性和一定的抗干扰性。     

基于稀疏强特征提取的三维地震数据完备方法

随着复杂储层地震资料特征筛选的机器学习技术的进步,如何有效地对参与地震属性优选和储层反演的地震样本进行采集和分析,成为目前智能地震预测领域的一个研究热点。目前的方法多着重于模型分类算法的改进,在标签的制作和采集方面不仅耗费大量时间进行人工标注,还存在标签不平衡情况下类内可靠性、类间平衡性不强等问题。为此,提出基于稀疏强特征提取的三维地震数据完备方法。首先,基于多数决原则的样本分割(Sample Segmentation Based on Majority Rule, SSMR)寻迹多尺度、多标签三维地震样本,进行采集、自动标注;然后,改进标签洗牌平衡方法(Improved Label Shuffling Balance Method, ILSB),通过“2+1”的样本增广平衡策略进行数据完备处理,改善样本采样不平衡性导致的模型训练偏向性;最后,利用基于最小L₁范数稀疏表示对奇异值分解结果进行强特征提取(Minimum L₁-norm Based Sparse Representation for Feature Extraction, L     

On multilevel voting

Summary In a distributed system mutual exclusion is often used to maintain consistency when restricted operations are performed. Mechanisms guaranteeing mutual exclusions should be both resilient and efficient. Resiliency implies high resource availability in the face of failures, while efficiency implies low overhead incurred by performing restricted operations. In this paper, we propose and study a general paradigm, called multilevel voting, which provides a general framework to assist in the design of resilient and efficient mutual exclusion mechanisms. The proposed method uses multiple level quorum consensus. Unlike another method based on the use of multiple quorum consensus, the proposed model only contains one type of integrity constraints. This has the benefit of being conceptually simple and easy to reason about. The strong resemblance with the traditional quorum consensus makes it easy for the proposed paradigm to embed any technique based on traditional quorum schemes. We show that the proposed model represents the exact class of coteries. This means that not only does it have all the power of coteries, but also all schemes under the model are correct. Thus, should the need arise, we can interchange two schemes freely without using any extra mechanisms to ensure correctness. We study a number of issues that have impact on performance such as the degree of a multilevel scheme and the order of a coterie. We explain how the model can be extended also to model the schemes for the synchronization of read and write of replicated data. We provide algorithms for the design of multilevel schemes in the context of mutual exclusion and that of read and write of replicated data. J. Tang received the M.S. degree in computer science from the University of Iowa in 1983 and the Ph.D degree in computer science from the Pennsylvania State University in 1988. Since 1988, he has been an assistant professor with the Department of Computer Science, Memorial University of Newfoundland, St. John's, Newfoundland, Canada. His current research interests include distributed computing, fault tolerance in distributed systems, database modeling and multidatabase systems.This work was supported in part by the Natural Sciences and Engineering Research Council of Canada, individual operating grant OGP0041916