IP网络QOS研究

本文首先讨论了IP QoS的基本概念和主要机制,然后详细分析了目前正在研究和实施的几种QoS模型的原理及其相互关系。并且基于这几种模型各自的优势和不足,探讨了将它们互相结合以更好实现IP QoS的可能方案。     

基于QoS预测模型的Web服务局部选择方法

提出一种基于QoS预测模型的选择方法,该方法不仅能够通过基于信誉度或BP网络的QoS预测模型较准确地查找到真正满足用户QoS需求的服务,而且能够在没有完全满足用户QoS需求服务的情况下,推荐尽量相似的服务以供用户作进一步选择。     

一种协同的基于P2P的VoD的节点选择方法

本文公开了一种协同的基于点对点(Peer-to-Peer,P2P)的视频点播(Video on Demand,Vo D)的节点选择方法,针对当前基于P2P的VoD的节点选择算法无法兼顾频谱资源的有效利用和提高服务质量(Quality of Service,QoS)的问题,本方法采用两个阶段通过不同的算法对节点进行选择。在第一阶段,引入注水法对目标方程进行寻优实现对节点的初步筛选;在第二阶段,采用模糊数学理论基于多种指标对第一阶段筛选得到的节点QoS性能进行评估并进行节点选择。本方法采用两阶段的节点选择策略,有效考虑了多种因素,特别是通过第一阶段对节点的初步筛选,能够更加有效地利用了频带资源。本方法通过引入模糊评判机制,综合考虑了多种影响QoS的因素,从而能够更好地满足用户对P2P VoD系统QoS的需求。     

机械传动系统设计方案的评判方法研究

机械传动系统设计方案选择会直接影响整个机械设计过程。本文对四种机械传动系统设计方案进行论述，包括支持向量机法、未确知测度模型、三级模糊综合评判法以及基于熵权的模糊AHP法，对比了不同评判方法所具备的特点，为机械传动系统设计提供理论依据。     

多种武器攻击下舰船电力系统生命力的模糊综合评判

应用模糊数学理论对舰船电力系统生命力进行了模糊综合评判，讨论了舰船电力系统在多种武器攻击下的模糊评估模型，并以某型舰艇的电力系统为例，通过对其子系统的模糊评估分析，得出整个电力系统的生命力指标。评估的结果说明了根据加权模糊综合评判模型，可以把模糊性很强的舰船生命力指标定量化，为电力系统设计方案选优提供依据。     

模糊综合评判与数理统计知识结合的目标识别效果评估

针对目标识别效果评估，利用数理统计知识确立了评估指标及测度方法。随后，使用模糊综合评判建立了一种开放的评估模型，该模型可以给出客观的、定量化的评估结果。最后，结合实测数据完成了仿真。     

IP QoS的体系结构及其发展

随着互联网的飞速发展，IP网上的VOIP受到了越来越多的关注。而QoS一直是VOIP在网络内大规模部署的关键性问题，所以有效的QoS体系结构对于VOIP来说是必不可少的。本文首先介绍了DiffServ和IntServ两种IP QoS协议的体系结构，然后分别分析它们的不足，最后补充了一种可能的实现机制。     

一种基于域的IP QoS分类方法

回顾了IP QoS的发展,总结了IP网中不同QoS技术的特征,提出了一种基于域的QoS分类方法,将各种QoS技术归结为时域、空域、逻辑域和层域。通过该方法可以更加深入地分析采用不同QoS技术对网络引入的代价,对构建一个合理的具有QoS保证的IP网具有一定的指导意义。     

基于QoS约束的服务推荐模型

随着Web服务数量的大规模增长,如何动态的选择出最适合用户需求的Web组合服务是目前的一个研究热点。本文提出了一种支持QoS约束的组合Web服务推荐模型,对服务集合进行预处理,根据需求选取具有高QoS的组群服务推荐给用户。     

支持QoS管理的下一代互联网网络管理流程

根据下一代互联网IP业务的灵活、动态管理和新业务扩展的需求,深入剖析了支持QoS管理的下一代互联网网络管理流程,给出了一个描述业务管理、网络管理与实际物理网络之间关系的分层透视模型,在此基础上提出了一套可行的IP业务QoS管理流程,并以IP-VPN业务的客户投诉应用场景为例分析了网络管理流程的实现.分析结果表明,该分层的QoS管理流程能够实现下一代互联网IP业务的业务流程自动化、业务管理灵活性和动态性,能够适应新业务的可扩展性和对业务的有效管理.     

An Optimized Algorithm for Resource Allocation for D2D in Heterogeneous Networks

With the emergence of 5G mobile multimedia services, end users’ demand for high-speed, low-latency mobile communication network access is increasing. Among them, the device-to-device (D2D) communication is one of the considerable technology. In D2D communication, the data does not need to be relayed and forwarded by the base station, but under the control of the base station, a direct local link is allowed between two adjacent mobile devices. This flexible communication mode reduces the processing bottlenecks and coverage blind spots of the base station, and can be widely used in dense user communication scenarios such as heterogeneous ultra-dense wireless networks. One of the important factors which affects the quality-of-service (QoS) of D2D communications is co-channel interference. In order to solve this problem of co-channel interference, this paper proposes a graph coloring based algorithm. The main idea is to utilize the weighted priority of spectrum resources and enables multiple D2D users to reuse the single cellular user resource. The proposed algorithm also provides simpler power control. The heterogeneous pattern of interference is determined using different types of interferences and UE and the priority of color is acquired. Simulation results show that the proposed algorithm effectively reduced the co-channel interference, power consumption and improved the system throughput as compared with existing algorithms.     

基于多感官整合的全感官广告沟通研究

目的建构一个全感官广告沟通概念模型。方法首先,基于人脑整合感知外界刺激,越多感官参与,效果越好,感官缺失则导致感知失调、失误等规律,提出全感官广告沟通概念;其次,从感官设计、感官传播、感官体验、整体知觉及心理行为反应等层面建构全感官广告沟通模型;最后,从挖掘、聚焦和互动角度提出全感官广告沟通策略。结论借助感觉模拟技术和"通感"技巧,策划"整体知觉"、创意"感官印记"、设计"感官触点",并根据"感官补偿"原则进行媒介投放,全感官广告可提升真实性、感染力和说服力。     

车用CAN总线测试平台的研发与应用

CAN总线在我国正在研发的电动汽车中得到广泛应用。为了制定我国自己的电动汽车通讯协议,基于提出的网络在环设计方法,研究开发了CAN总线实时仿真测试平台。该平台可对CAN总线通讯网络性能、单个ECU通讯性能进行分析、测试及评价,用于车用CAN总线相关技术的研发及车载CAN总线通讯网络性能的测试。     

A cross-layer adaptive algorithm for multimedia QoS fairness in WLAN environments using neural networks

The authors address the problem of providing fair multimedia quality-of-service (QoS) in IEEE 802.11 distributed co-ordination function-based wireless local area networks in the infrastructure mode where mobile hosts experience heterogeneous channel conditions due to mobility and fading effects. It was observed that unequal link qualities can pose significant unfairness of channel sharing, which may thereby lead to the degradation of multimedia QoS performed in adverse conditions. A cross-layer adaptation scheme that provides fair QoS by online adjusting the multidimensional medium access control layer backoff parameters in accordance with the application-layer QoS requirements as well as the physical-layer channel conditions was proposed. The solution is based on an optimisation approach, which utilises neural networks to learn the cross-layer function. Simulation results demonstrate that the proposed adaptation scheme can tackle heterogeneous channel conditions and random joining (or leaving) of hosts to achieve fair QoS in terms of throughput and packet delay.     

Educational Innovations in Multimedia Systems*

Multimedia systems have emerged as one of the fastest growing segments of computing systems and thus need to be well integrated into a computer engineering curriculum. Fortunately the teaching and learning of multimedia systems can be aided with novel instructional techniques based on multimedia. The Multimedia Curriculum project at the University of Massachusetts Amherst is developing a unified set of instructional materials on the engineering techniques used in the design and test of hardware, software and networks for multimedia. This large project includes three facets: 1) multimedia instructional modules using web‐linked Digital Video Disks, 2) multimedia communication utilities to facilitate student interaction, and 3) multimedia component design projects. In this paper, we explain our approach to using multimedia as both content and instructional technology and briefly present preliminary results in each of the three facets.     

ATM-多媒体通信网络的最佳选择

多媒体通信适应日益发展的通信业的需求,成为通信业发展的趋势。多媒体通信对通信网络提出了严格的要求,通过分析ATM的主要技术,论证了ATM最适合多媒体通信应用,具有广阔的前景。     

多媒体与现代包装设计

多媒体技术处于信息技术发展的前沿,反映了高技术的特性.本文从多媒体数字技术在现代包装的设计方式、与客户的沟通及设计评价、产品包装的流通和销售角度探讨了多媒体对现代包装设计产生的影响和作用.     

激光通信系统性能的灰色聚类分析

激光通信系统需要评价和定量分析,且存在多个评价指标.针对评价指标的模糊性、相对性和多样性,为了对激光通信系统进行定量评价,采用灰色系统理论中的灰色聚类分析法.首先对具有模糊性和相对性的评价指标进行灰量白化,然后将激光通信系统按照聚类指标进行灰色聚类,计算不同激光通信系统所有指标的综合聚类效果,最后以聚类类型作为各系统定量评价的依据.该方法将多指标决策问题转换为单一指标决策问题,它是一种定量评价激光通信系统的新方法.     

水声通信系统性能评估方法研究

水声通信系统性能主要受水声信道和通信体制影响,通常采取海洋水声试验的手段进行性能测试,但这需要进行多次不同信道条件下的试验才能得出正确的评估结论,难度较大且成本较高。因此,建立准确的水声通信系统性能评估模型和评估方法,对于通信系统设计及性能预测显得尤为重要。从水声信道模型开始分析,结合水声通信特点,讨论了典型水声通信接收机结构,提出了一种通用水声通信系统性能评估模型和方法,并针对采用QPSK调制的通信系统性能进行了评估,结果与海试数据较为接近。     

Quality of service for multimedia traffic using cross-layer design

Quality-of-service (QoS) guarantees are critical for the transmission of multimedia traffic over mobile wireless networks. Currently, wireless networks provide QoS guarantees using the legacy layered protocol architecture where each layer provides a separate, independent solution, with its own optimised adaptation and protection mechanisms. Cross-layer design has been proposed as a methodology to extend that paradigm in wireless links where there is interdependence between the layers and hence opportunity for information sharing. Recently, cross-layer adaptation mechanisms have been proposed which attempt to solve the QoS provisioning problem. However, most of these mechanisms only use the lower (physical and data link) layers and the possibility of using higher protocol layers remains unexplored. As a result, restrictions are placed on the system which introduces functional and efficiency limitations. Here, one such limitation is highlighted, namely the inability to insert more than one class of traffic in a physical layer frame. A physical and application layer cross-layer adaptation mechanism is then proposed, which overcomes this limitation. The performance results of the scheme show that the cross-layer mechanism can be efficiently applied for the purpose of providing QoS guarantees for multimedia traffic.