基于节点定位的无线传感器网络密钥分配方案

本文从无线传感器网络的密钥分配体系出发,提出了一种基于节点定位信息的随机密钥预分配方案.首先简要介绍了传统随机密钥预分配方案及其改进方案存在的不足,然后根据节点定位信息和密钥的相关度划分,给出我们新密钥分配方案LRKPS,并从LRKPS的共享密钥的概率、网络连通度、被俘获的抵抗性等方面,与随机密钥预分配进行了分析比较,结果表明我们的算法在这些方面有一定的优势.     

一种改进随机密钥预分配的网络分簇密钥管理方案

由于原随机密钥的预分配的管理方案节点存储空间要求高、抗毁性较低,提出了一种使用公钥和引用Hash表中开放式并增加密钥管理的非身份认证密钥管理方案.改进的方案中降低网络节点存储空间要求,增强无线传感器网络抗毁性能.Matlab仿真表明,此方案中单个节点密钥存储量减少至少一半;网络中簇内节点连接率为100%;在安全性方面,能有效减少节点密钥破解的数量,未捕获节点的密钥暴露概率是比原随机密钥的预分配的管理方案要低20%以上.     

传感器网络中一种混合密钥管理方案

提出了一种混合密钥管理方案.该方案借助于Blom矩阵和密钥池,来完成密钥预分配,使得所有的簇头间、节点和它的簇头间,以及节点之间都能进行安全通信.该方案还能够支持网络的拓扑结构的变化,并且能动态的管理密钥信息从而解决了密钥泄漏等问题.进行了网络安全及性能分析,包括安全性能比较、储存空间比较、通信与计算开销比较.仿真结果显示,与已有的一些密钥方案相比,该方案提高了网络的安全性,减小了存储空间.     

一种无线传感器网络密钥动态预分配策略

为了实现无线传感器网络中的安全通信，传感器结点间传递的信息就必须被加密和认证.所以密钥分配与管理就成为基本问题之一.分析了随机对密钥预分配策略的不足，将其与基于配置信息的密钥预分配策略相结合并进行改进，提出了一种新的密钥动态预分配策略.     

一种高连通率的传感器网络密钥预分配方法

密钥管理是无线传感器网络安全的基础,其中密钥预分配是可行性比较高的密钥管理方法,节点之间的共享密钥的概率一直是密钥预分配中比较重要的性能指标,可是现有的无线传感器网络密钥预分配方案大多存在节点间密钥共享概率低或者共享概率不稳定的问题.结合Blom对称多项式,通过改进TD方法,提出了一种改进的密钥预分配方法,该方法能够实现稳定的节点间高密钥共享概率,从而保证了无线传感器网络的安全连通,此外该方法还具有灵活易变的特性,可以改变传感器分组数目以及传感器存储的密钥个数,满足实际需求.     

异构无线传感器网络动态混合密钥管理方案研究

在需要进行安全通信的无线传感器网络应用中,复杂的公钥系统难以在资源有限的传感节点上实现,而基于随机预分配的对称密钥系统有节点连通性不强、密钥存储空间过大、密钥协商过程复杂且不灵活等问题。因此,在异构无线传感器网络基础上,提出一种联合公钥机制与私钥机制的混合密钥管理方案(DHKAS)。该方案使用一种简便可靠的方法,以较小的代价解决了密钥管理中最关键的节点认证问题。分析结果显示,所提方案有效提高了节点的连通性、减少了密钥存储空间,并增强了网络抗攻击能力。     

基于三维网格的密钥预分配方案

提出了三维网格密钥预分配方案,此方案不仅有高连通性、低负担等优点,在抗攻击方面也比已有的二维网格方案、基概率方案、q复合方案、随机成对密钥方案及随机子集分配方案有更好的性能.     

基于分簇的无线传感器网络动态密钥管理方案

针对现有无线传感器网络密钥计算量过大、存储空间过多和管理不够灵活的问题,在基于分簇的网络拓扑结构基础上,引入虚拟网格技术,提出基于分簇的无线传感器网络动态密钥管理方案。在簇头与活动节点之间采用基于簇基密钥的预分配策略进行通信,在簇头之间采用基于Blom矩阵并结合随机数的对密钥进行通信,该方案能在活动节点或簇头被捕获或能量耗尽时实现密钥的动态更新。与现有方案相比较,此方案能动态更新密钥,有着更好的安全性并具有良好的扩展性。     

基于部署信息的无线传感器网络密钥预分配

针对无线传感器网络的频繁移动性,提出了一种有效的随机密钥预分配方案.该方案采用正方形对网络进行分区,在覆盖全网的同时有效地减少了重叠区域.节点仅需预分配数量较少的密钥,就能够以很高的概率建立共享密钥,即使存在大量的移动节点仍能保持较高的连通概率.理论分析与仿真数据表明该方案不但在连通性和安全性方面具有较好的性能,而且节点存储的密钥数量最多可节约60%以上.     

无线传感器网络安全方案分析与设计

本文首先分析了无线传感器网络所面临的安全威胁,探讨了无线传感器网络安全需求。在此基础上提出了一种新的密钥管理方案——基于节点双密钥链的密钥管理方案。新方案采用分组部署的方式,为每个传感器节点预装入双密钥链。新方案能提高网络安全连通概率、负载、抗节点俘获能力等性能,并支持节点的移动。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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