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1.
在对原有亲密伙伴安全通信方案及IPSec协议深入研究的基础上,结合移动IPv6网络中移动节点的特性,提出了一种基于移动IPv6网络的安全通信扩展方案.通过使用IKE移动性支持协议 (Mobile IKE,MOBIKE) 、在移动网络中构造动态分布式管理节点,解决了原方案不能直接运用于移动网络以及网络带宽利用率低的问题,使IPSec策略在移动IPv6网络中得到了灵活的应用.最后,通过对新方案进行仿真和分析证明了该方案的可行性.  相似文献   

2.
IETF在移动IPv6(MIPv6)基础上制定的网络移动性(NEMO)协议规范中,嵌套移动子网的数据传输存在次优路由和多层封装,影响数据包的传输效率.为此,该文在层次移动IPv6(HMIPv6)的基础上,提出了嵌套移动子网的优化方案HRO,引入MAP域优化节点的位置管理,建立优化路由传输数据包.提出路由评估机制,建立了传输开销和传输效率的解析模型.解析结果显示,与NEMO基本支持协议相比,优化后的方案提高了数据包传输效率,更有效地利用了网络资源.  相似文献   

3.
移动节点在两个不同子网之间移动时将产生切换,移动节点的切换技术是保证实时业务服务质量的关键问题之一,目前,IETF正在开发快速切换和层次型移动IPv6来为移动IPv6提供切换机制。在详细介绍了两种技术原理之后,提出了一些改进,并给出了一个在层次型移动IPv6模型下的快速切换方案。  相似文献   

4.
针对目前移动自组网(MANET)无法提供成熟的Anycast服务这一问题, 提出了一种在MANET中实现Anycast服务的通信模型.此模型提出了无需进行地址重复检测、IPv6地址自动分配的方案以及移动节点加入Anycast组的方法. 模型中的Anycast移动组节点在不同子网之间进行切换时,Anycast移动组节点无需进行地址注册也无需建立隧道机制.在模拟环境下实现了此模型,并对模型的数据包接收率等性能参数的实验数据进行了分析和讨论.  相似文献   

5.
为了提高分级移动IPv6模型对于移动定位点出错后的恢复能力,对分级移动IPv6模型进行改进,提出了一种冗余的分级移动IPv6模型.通过在移动节点与多个移动定位点问建立隧道,提高移动定位点出错后移动节点与通信节点和家乡代理之问的错误恢复能力.另外采用主动探测的方式,提高发现移动定位点出错的能力,进一步提高了移动IPv6应对移动定位点出错后的恢复能力,提高分级移动IPv6的可靠性.最后通过模拟验证了相对于传统分级移动IPv6,本文模型能将MAP错误恢复时延减少65%.  相似文献   

6.
移动IPv6同绑定更新、绑定确认和绑定请求密切相关,移动节点通过绑定更新同家乡代理或通信伙伴取得联系,讨论了移动节点的绑定操作,分析了支持移动特性的分组,结果表明IPv6能够更好地支持移动特性。  相似文献   

7.
移动代理技术在移动计算中的应用   总被引:1,自引:0,他引:1  
分析讨论了移动代理(Agent)技术在移动计算中的应用.随着因特网的广泛应用和移动主机用户的不断增加,使对基于移动IP的研究显得更为重要.首先分析了IP对移动节点的支持和实现机制,然后介绍并讨论了移动代理技术、隧道技术和安全性问题,最后研究了移动代理技术在移动计算中的具体应用.  相似文献   

8.
刘剑  孙世新 《科技资讯》2007,(16):126-127
移动IPv6虽然解决了网络层的移动性问题,但是其切换性能并不乐观。为了适应实时应用的需求,IETF提出了移动IPv6快速切换协议以减少移动IPv6的切换时延。通过研究802.11的切换过程和移动IPv6快速切换协议,本文设计并实现了一种在802.11网络中移动IPv6快速切换方案。  相似文献   

9.
一种基于IPv6网络移动MPLS资源预留方案   总被引:1,自引:0,他引:1  
随着信息化速度的快速提升,未来网络世界中快速移动交换和高效宽带传输将是必然的趋势。在快速移动交换领域内如今研究的热点就是移动MPLS技术,而高效宽带传输在现如今的整体带宽条件下还很难得到满足,于是就需要使用到RSVP资源预留技术来保证现有带宽条件下的高效传输。通过利用IPv6自身具有的移动性和QoS保障方面的优点,提出了一种基于IPv6的移动MPLS中的资源预留方案,给出了在IPv6环境下快速高效、移动交换的一种实现方法。  相似文献   

10.
结合移动IPv6 MPLS(Multiprotocol Label Switching)的几种方案,分析它们各自的优缺点后提出一种改进的基于MPLS(多协议标签交换技术)的移动IPv6动态分级结构的模型。在MPLS网络中引入了多个网关外地代理GFA,保留了基于MPLS的移动IPv6分层结构局部注册的优点,改进了其依靠单个网关接入核心网的缺点.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
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。  相似文献   

14.
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.  相似文献   

15.
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-  相似文献   

16.
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-  相似文献   

17.
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  相似文献   

18.
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  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<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  相似文献   

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