一种实现区分服务和带宽公平性的队列管理算法

区分服务(DiffServ)体系对于可靠型(AF)服务的OUT数据包和尽力型(BE)服务的数据包并未提供任何优先处理机制。为避免某AF服务的数据流占用过多的网络带宽，提出了一种名为TD&BF的核心无状态队列管理算法，该算法能在保证AF业务承诺服务速率的前提下，将剩余带宽公平地分配给BE业务及AF业务。     

一种实现区分服务和带宽公平性的队列管理算法

区分服务(DiffServ)体系对于可靠型(AF)服务的OUT数据包和尽力型(BE)服务的数据包并未提供任何优先处理机制。为避免某AF服务的数据流占用过多的网络带宽，提出了一种名为TD&;BF的核心无状态队列管理算法，该算法能在保证AF业务承诺服务速率的前提下，将剩余带宽公平地分配给BE业务及AF业务。     

基于SLA的IP DiffServ网络的业务实现机制

为了在区分服务（DiffServ）网络中实现有差别、可定制、有服务质量（QoS）保证的业务,改进了DiffServ分层业务模型并提出了完整的基于服务等级协定（SLA）的IP业务实现机制,解决了客户SLS到提供商SLS的映射问题,描述了IP业务实现流程。原型系统的实现验证了该机制的有效性。     

网络业务聚类研究

在构建一体化承载网的时候,需要对现有的电信业务、广电业务和互联网业务进行科学聚类.文章总结了一些典型的业务聚类方法:ATM、DiffServ和ITU-T的业务聚类,提出了一些关于一体化承载网业务聚类的建议.     

MPLS／BGPVPN的QoS的应用

目前VPN技术在各类网络中的应用大量存在,随着网络技术的发展,IP网络中不仅单独承载普通数据业务,3G语音、视频、数据等业务融合承载,综合应用,对网络的承载能力有了更高的要求。而各类业务在VPN中的大量应用,对于使用VPN对各类业务承载的时延、抖动、丢包率等提出更严格的要求。本文试对目前应用最广泛的MPLS／BGPVPN业务中的DiffServ模型的QoS的典型应用场景进行阐述,探讨对VPN业务的QoS保障。     

基于公平性的DiffServ服务质量模型的研究

随着多媒体业务在Internet上的广泛应用，响应流和非响应流间带宽享用的公平性问题，严重影响了网络的性能.为此提出了一种基于公平的DiffServ流控制机制，以解决在资源共享环境中，各共享者之间的公平性问题.具体到DiffServ，指同一聚集流内各微流共享资.DiffServ流控制机制是通过在DiffServ模型中添加特定的队列管理算法SCALE-WFS，在区分服务模型的基础之上，提出一种既可以保证各个微流之间的公平性问题并且不会占用系统的太多的资源的新模型，在一定程度上解决了DiffServ域流间的公平性问题.     

基于公平性的DiffServ带宽分配解决方法

分析了DiffServ带宽分配的公平性问题,提出了一种采用网络数据流划分和WRED加权早期随机检测基于公平性的DiffServ带宽分配解决方法。实验表明该方法能公平的分配网络带宽资源及提高网络的吞吐率,实现区分服务DiffServ网络中端到端的QoS。     

一种基于DiffServ/RSVP的优化隧道机制

分析了DiffServ体系中四种聚集流的服务质量保证,给出了DiffServ在IPv4广域骨干网上不能实现QoS保证的原因。在此基础上,引进了接纳控制机制,即在DiffServ体系中引进了RSVP资源预留协议,探讨了基于Diffserv/RSVP体系的服务质量,得出节点路由表庞大的信息量对Diffserv/RSVP体系QoS保证有一定的影响,在制定了一种优化策略后,证明了基于Diffserv/RSVP体系的QoS是有保证的。从而得到一种具有QoS保证的隧道机制。     

无线非对称中继网络的统计QoS保证

针对目前中继网络动态资源分配最优解尚不完善的问题,通过将信息论和有效容量有机地结合,独立求解出估计转发(EF)中继网络动态资源分配的最优解,并以典型网络为例,基于动态资源分配提出了一种自适应中继网络方案,可以根据系统QoS指数要求在现有放大转发(AF)、解码转发(DF)和估计转发(EF)3种中继协议中进行动态选择.数值与仿真分析表明,动态资源分配方案可以很好地在给定系统QoS指数限制下最大化中继网络的有效容量,同时自适应中继网络方案比传统的单一中继方案能更好地提高系统的吞吐量.     

煤炭企业多媒体综合业务数字网络服务质量模型

为提高煤炭企业多媒体综合业务数字网络的服务质量(QoS),针对煤炭网络及其业务特点,提出煤矿企业QoS层次网络结构和网关节点模型;借鉴区分服务DiffServ思想,利用每跳行为PHB(per hop behavior)分类与标记煤矿网络业务,提出了适用于煤矿的具有区分服务能力的队列分组丢弃算法和队列分组调度算法.结果表明:实施该服务质量模型,即使多业务大数据量传输时,与煤矿安全生产密切相关的业务均能得到预定带宽,分组平均延时稳定地维持在40.4～41.2ms之间,延时抖动小于0.46ms,分组丢失率为零;而拾荒业务只能占有剩余的带宽,分组平均延时在42～56ms之间变化,业务抖动在1.7～3.6ms之间变化,分组丢失率高达47.6%.     

无线传感器网络下中继辅助的分布式估计策略

与传统的星形拓扑结构下无中继辅助估计策略相比,新颖的中继辅助分布式参数估计(RADE)
策略能利用中继节点协作传输,提高系统估计性能,对传输能量和处理能力受限的无线传感
器网络有极大帮助. 根据中继节点的信号处理方式,分为放大转发(AF)和估计转发(EF)2种
中继辅助分布式估计策略. 通过凸优化算法得到上述2种估计策略的闭式解. 仿真结果表明
,此策略能在不额外占用带宽的情况下提供更好的估计性能.     

Synthesis Mechanism and Material Characterization of C_4AF Obtained by the Self-propagating Combustion Reaction Method

To investigate the influence of preparation process on the properties of synthesized C_4AF,the powder was prepared via the self-propagating combustion reaction(SPCR)method using urea as fuel and metal nitrates as cation precursors.Synthesis mechanism of the SPCR method,calculation and adjusting principles of urea dosage were detailedly introduced.Material characterization of synthesized C_4AF was performed with the aid of X-ray diffractometry,Fourier transform infrared spectrometry,scanning electron microscopy,energydispersive X-ray spectroscopy,~(27)Al nuclear magnetic resonance and isothermal microcalorimetric technique.Remaining content of transition phase of calcium carbonate in synthesized C_4AF was determined by quantitative analysis of X-ray diffractometry.It was found that there was no difference in the hydration behavior of C_4AF synthesized by the SPCR method and the traditional solid-state reaction(SSR)method.C_3AH_6 and amorphous iron(III)hydroxide(Fe(OH)_3)would be formed during the hydration of C_4AF while CH not.Crystallite size of synthesized C_4AF was 16.1?and the apparent activation energy was 36.2 kJ/mol.Coordinated condition of Al in C_4AF can be detected by ~(27)Al NMR technique,but the peaks were broadened and the intensities were relatively low,supporting the use of ~(27)Al NMR for the quantitative analysis of C_3A in Portland cements.     

Synthesis Mechanism and Material Characterization of C<Subscript>4</Subscript>AF Obtained by the Self-propagating Combustion Reaction Method

To investigate the influence of preparation process on the properties of synthesized C₄AF, the powder was prepared via the self-propagating combustion reaction (SPCR) method using urea as fuel and metal nitrates as cation precursors. Synthesis mechanism of the SPCR method, calculation and adjusting principles of urea dosage were detailedly introduced. Material characterization of synthesized C₄AF was performed with the aid of X-ray diffractometry, Fourier transform infrared spectrometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy, ²⁷Al nuclear magnetic resonance and isothermal microcalorimetric technique. Remaining content of transition phase of calcium carbonate in synthesized C₄AF was determined by quantitative analysis of X-ray diffractometry. It was found that there was no difference in the hydration behavior of C₄AF synthesized by the SPCR method and the traditional solid-state reaction (SSR) method. C3AH6 and amorphous iron (III) hydroxide (Fe(OH)₃) would be formed during the hydration of C4AF while CH not. Crystallite size of synthesized C₄AF was 16.1 Å and the apparent activation energy was 36.2 kJ/mol. Coordinated condition of Al in C₄AF can be detected by ²⁷Al NMR technique, but the peaks were broadened and the intensities were relatively low, supporting the use of ²⁷Al NMR for the quantitative analysis of C₃A in Portland cements.     

Research of MPLS traffic engineering over differentiated services

An approach to traffic engineering that uses differentiated services(DS) and multi-protocol label switching (MPLS) to provide quantitative network quality of service(QoS) guarantees over an IP network was proposed.The traffic associated with assured forwarding (AF) Per-Hop behavior(PHB) in differentiated services enabled IP network was modeled.Furthermore,the effect of such traffic on network resources with the objective of developing efficient traffic engineering methodologies was analzed and the optimization problem relating to traffic engineering in DS newtwokrs with an MPLS core was formultate.The service received by TCP and UDP flows when they share either a link or a MPLS traffic trunk was also compared and found that in order to benefit from traffic engineering,MPLS trunks should be implemented end-end (first router to last router).if some part of the network is MPLS trunk0unaware,the benefits are reduced or eliminated.     

针对生态型城市规划的生态足迹影响因子分析

针对上海欲建设生态型国际大都市的目标,为保证EF能给其生态规划提供更具体、科学的分析依据,在W ackernagel提出生态足迹方法的基础上,采用国际均值作对比计算,以上海的长期发展实际数据为基础,计算其动态的EF.根据EF的计算结果,结合调查数据分析影响EF的关键因子,发现地区发展状况、人均GDP、科学技术发展、人口密度、人口城市化水平与EF有一定的相关性.据此,提出EF的多元性,进一步说明EF作为衡量区域可持续发展具有一定的局限性,仅能作为生态规划中的参考依据.     

西北半干旱区城市可持续发展状况动态分析——以兰州市为例

西北半干旱区的城市在气候、植被等自然地理特征方面有不同于其他地区城市的发展条件,生态足迹分析法现已广泛应用于各种可持续发展的度量,通过对长时间序列生态足迹发展的测度,能有效克服生态足迹静态性缺陷,定量评价和分析区域可持续发展程度的轨迹和动态变化以及趋势。应用该方法对兰州市的可持续发展状况进行了评价和分析,最后,根据研究分析结果,提出了相应建议。     

我国商业银行信用卡顾客忠诚影响因素研究

在理论研究的基础上,构建了我国商业银行信用卡顾客忠诚形成的影响因素假设模型,并采用实证的方法,运用SPSS统计软件对调查数据进行整理和分析。研究发现：服务质量,顾客信任对信用卡顾客的态度忠诚和行为忠诚是正相关关系,转换成本与信用卡顾客的行为忠诚是正相关关系,而与顾客的态度忠诚是负相关关系。