OSPF协议中路由表计算的测试例生成方法

本给出了OSPF协议中路由表计算部分的Petri网模型和产生测试例的方法,以算法中的外部路由计算为例,详细介绍了如何从协议本形式化为Petri网模型,然后再多Petri网生成测试例的方法,并给出了方法所采用的测试标准。     

网络路由收敛性能测试研究

在网络建设和运行中,采用测试的方法对其性能进行评估对于网络的正常运营具有重要的意义.本文研究了网络路由收敛性能测试方法,为得到路由收敛性能指标,对OSPF和iBGP的路由收敛时间进行了测量.提出了一种简化的路由收敛时间测量方法,通过测量数据平面的传输性能指标,对路由控制平面的收敛时间进行估算.该方法对于测试设备要求不高,实施简单方便.采用该方法在CERNET2投入运营之前对其进行了路由性能测试,实验结果表明CERNET2在路由变化时具有较好的路由收敛性能.     

OSPF路由选择协议研究

OSPF是新型的路由选择协议,被广泛应用于大型网络之中.从阐述OSPF的结构模型入手,分析了OSPF在一个区中的工作机制,以及各区之间路由信息的交换.     

OSPF应用与设计

OSPF作为一种内部网关协议（Interior Gateway Protocol,IGP）,用于在同一个自治域中的路由器之间发布路由信息。它是一种连接状态协议,区别于距离矢量协议,OSPF具有支持大型网络、路由收敛快、占用网络资源少等优点。     

基于属性的协议互操作性测试的TTCN-3实现

目前对路由协议的测试主要集中在一致性测试,对于像OSPF这样的复杂协议,对其进行互操作测试非常必要.传统的协议互操作性测试是基于被测系统的形式化模型生成测试序列,对测试序列进行测试例抽象,最终得出测试判定.传统方法简单易行,但当测试序列较长时相应问题随之而来.采用TTCN-3语言对基于属性生成的测试序列进行测试用例的实现,结果说明采用基于属性作为模型选择的方法并结合使用TTCN-3实现测试用例可以有效提高测试效率.     

基于Petri网模型的OSPF路由处的测试序列生成

OSPF协议是一种动态路由协议,它利用内部的链路状态数据库来维护和计算路由,它的路由算法是本协议的关键部分,本给出了路由算法的Petri网模型,并使用控制流和数据流测试相结合的一种方法,在此基础上产生测试序列。     

OSPF路由协议的安全性分析

介绍了OSPF动态路由协议及OSPF的安全特性,分析了OSPF当前版本可能遭受的攻击,指出了OSPF存在的漏洞。     

实验性路由协议仿真测试平台设计

通过对网络设计架构影响网络路由性能的分析,描述了局部网络参数的改变对整体路由环境影响的重要性.设计了一个实验性路由协议仿真测试平台,并模拟了OSPF协议在该平台上运行时的协议行为,进行了模拟故障分析.利用实验性路由平台可以为网络规划设计工作提供经济有效的实验环境,有效地提高工作效率,降低故障发生率.     

快速连锁网络攻击方法研究

针对当前网络中广泛使用的路由协议OSPF的工作原理和特点,提出了基于链路状态公告LSA攻击的网络攻击方法,并对此攻击方法作了详细介绍,通过对这种方法的识别可以为网络管理员在策略设定上提供依据.     

OSPF区域规划在实际应用中的研究

OSPF是一个典型的链路状态路由协议,能够解决许多距离矢量型路由协议所不能解决的问题,目前在移动网络逐渐IP化进程中,已广泛应用于软件交换的IP承载网、GPRS接入CMNET骨干网、DCN骨干网的IP网络上。本文从OSPF的路由算法和路由维护等方面来解释OSPF的工作原理,并分析了在实际应用中的城域网骨干流量引导问题。     

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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