基于数据流特性的MPTCP数据流调度算法研究

基于广域网中使用MPTCP协议进行数据传输时,由于短流的传输数据量小,每条子流的拥塞窗口在其生命周期内保持很小的状态,这使得1个数据包的丢失也可能导致超时现象发生,从而增大数据流的完成时间,为此,提出一种根据MPTCP数据流特性进行MPTCP数据流调度的算法MPTCP-FSFSm(multi-path TCP flow scheduling based on flow size)。首先,MPTCP-FSFS算法根据MPTCP数据流需要发送的数据量将MPTCP数据流分类;然后,发送端根据当前每条路径往返时延进行MPTCP数据流调度:对于短流,选择往返时延最小的若干条路径进行数据流传输;对于长流,使用所有的路径进行数据流传输。研究结果表明:与MPTCP相比,MPTCP-FSFS在保证长流吞吐率的基础上,能够明显降低短流的数据流完成时间,同时提高数据流平均吞吐率。     

IP协议分析与数据包分解研究

在计算机网络中,入侵数据通过网络协议在网络中传输,对计算机安全有着很大的威胁。通过对数据包级的IP协议进行详细的分析和研究,对基于IP协议的入侵数据进行了实验分析,目的是要从中发现恶意的数据流,从而了解这些恶意数据流的特点。实验结果表明,许多入侵攻击是通过IP协议数据包进行的。因此,通过对正常的IP协议和带有攻击的IP协议进行解析和分析,得出这些攻击的特点,更好地完善入侵检测系统。     

存储特定流数据的通用框架

通过仔细研究存储流数据的各种应用的共同特征,提出了一种数据流存储模型.在数据流存储模型基础上,采用先进的基于组件的开发方法,实现了一个存储流数据的通用框架,通用框架采用本体技术来解决语义互操作性.测试结果表明,通用框架可以调用一组用户提供的过滤算法,筛选出指定数据流中符合条件的信息,将它们成批存储到数据库中.用户可以通过定制和配置参数的方法,在各种不同的应用环境中重用该通用框架.     

基于数据平面可编程的负载均衡算法

针对目前网络数据平面存在僵化现象,导致网络中数据流不均衡的问题,提出了一种基于数据平面可编程的负载均衡算法。首先通过带内网络遥测(INT:In-band Network Telemetry)技术获取网络实时状态信息,然后利用提出的BD-ECMP(Bandwidth and Delay Equal-Cost Multi-Path Routing)算法选择数据流的最佳传输路径。采用编程协议无关的包处理器(P4:Programming Protocol-Independent Packet Processors)语言对SDN网络数据平面的数据流进行优化处理,从而实现网络负载均衡。仿真实验结果表明,与传统ECMP算法相比,BD-ECMP算法在平均流完成时间、网络吞吐量及网络丢包率等方面具有明显优势。     

一种基于关联规则挖掘的IP定位方法

针对IP定位数据库如何及时更新IP定位数据并同时保证其定位准确率和覆盖率的问题,提出一种基于关联规则挖掘的IP定位方法(IPGEL).首先,结合traceroute网络测量数据和已有IP定位数据库中IP定位数据,获取关联规则挖掘的路由路径数据集.其次,利用国内互联网分层结构的路由特性和关联规则挖掘,在对路由路径数据集进行数据分析的基础上对数据集内的IP分类并定位,同时利用马尔可夫模型对数据集外的IP进行补充定位.最后,使用交叉对比验证和地标验证相结合的方法验证IPGEL方法的准确性.结果表明,IPGEL方法在提高IP定位准确率和覆盖率的同时有效提高了已有IP定位数据库的可信度.     

可程控式继电器电气参数在线检测系统的开发

随着"工业4.0"的发展,制造业对生产过程要求更加网络化和智能化.针对目前继电器电气参数检测过程不能自适应不同型号继电器,网络化不足等缺点,设计了一种基于STM32F407单片机的电磁继电器电气参数在线检测系统.该系统使用基于轻量级IP(light weight IP,Lw Ip)的莫迪康总线(Modbus)通信协议,通过有线或者无线的方式实现了数据的网络化在线传输,而用户可以通过本地或者以太网实现系统参数的线下、线上设置.经过多次的随机测量实验,该检测仪的数据变异系数和相对误差均小于5%.     

IP流量规划对网络延迟性能的影响

IP流量规划 (TrafficEngineering,TE)基于多路径路由优化网络的流量级、资源级的性能。由于数据流的不同数据包沿不同路径到达目标结点 ,TE动态优化使数据流的服务质量 (QualityofService ,QoS)参数延迟、延迟抖动等具有不确定性。对此 ,研究了TE选择多路径和分割数据流对延迟等的影响 ,结果说明 :TE能改善网络延迟性能     

GRE over IPsec VPN结合NAT的构建方案研究与实现

IPSec和GRE均为构建虚拟专用网所采用的技术,其自身都有其局限性,IPSec不支持广播、组播和非IP数据流,而GRE不支持数据加密.分析了IPSec和GRE各自的优势,结合IPSec的安全性和GRE对广播、组播和非IP数据流支持的特点,提出了GRE over IPSec VPN结合NAT的构建方案,实现了两个局域网之间单播或组播数据的保密通讯,通过运行EIGRP协议交互内网路由信息,进而使用NAT技术实现局域网内部用户脱离VPN访问Internet.依据提出的构建方案,绘制了组网拓扑图,并基于GNS3进行了仿真实验,验证了方案的安全性和可实施性.该方案既满足了不同局域网之间安全通信的需要,也满足了局域网内部用户访问Internet的需求.     

IP流量规划对网络延迟性能的影响

IP流量规划（Traffic Engineering,TE)基于多路径路由优化网络的流量级、资源级的性能。由于数据流的不同数据包沿不同路径到达目标结点，TE动态优化使数据流的服务质量（Qualty of DService,QoS)参数延迟、延迟抖动等具有不确定性。对此，研究了TE选择多路径和分割数据流对延迟等的影响，结果说明：TE能改善网络延迟性能。     

流媒体技术及其在教育中的应用

流媒体指的是通过网络传输的、能够在本地终端实时回放的、具有实时特征的媒体内容编码数据流。流媒体实现的关键技术就是流式传输，即通过网络获得平滑的数据流。     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

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     

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

正~~