基于Ad Hoc多QoS约束的多播路由协议

针对移动Ad Hoc网络特点，研讨了Ad Hoc网络中其有多QoS约束的多播路由问题，其中主要包含延迟、延迟抖动、带宽、代价等QoS约束。描述了一种适应于研究Ad Hoc网络QoS多播路由的网络模型，提出了Ad Hoc网络中一种具有多QoS约束的多播路由协议。给出了MQAP的路由实现过程，进行了正确性证明和复杂性分析。仿真实验结果表明，MQAP为Ad Hoc网络多QoS约束多播路由提供了一种新的有效途径。     

MAODV协议的QoS延伸

研讨了Ad Hoc网络中具有QoS约束的多播路由问题和网络模型,提出了一种基于延伸MAODV（Multicast Ad Hoc On-demand Distance Vector）多播路由协议的延时、带宽和包丢失率等度量的QoS多播路由协议。仿真实验显示该协议较好地改进b 端到端传输延时、带宽利用率和传输性能,为Ad Hoc网络QoS多播路由提供了一种新的有效途径。     

基于连通度的Ad hoc网络路由协议研究与仿真*

对Ad hoc网络各种路由协议进行仿真评估,分析它们在不同约束条件下不同度量的相对性能,是了解与学习路由协议性能的重要手段.目前的度量标准主要集中在吞吐量、延时、抖动、丢包率等QoS因子或路由负载、寻路时间等外部特性上,还没有以Ad hoc网络系统本身的连通度作为度量标准进行仿真,评价各种路由协议在不同试验条件下对于同一网络系统连通度的影响的相关研究.基于能量模型、节点密度、停留时间及移动速率四种约束条件对MANET提出的四种路由协议进行了关于网络连通度的仿真与评估,给出了这方面的初步结论.     

Ad Hoc网络中一种多路径QoS路由协议

在移动Ad Hoc研究中,QoS研究重要方面,虽然在传统网络中多路径的路由协议研究已相当成熟,但是大多数Ad Hoc路由协议都是基于单路由的,而且并不能很好的支持QoS约束。本文对现有DSR的协议的基础上,加入多径使其满足一定的延时约束,提出了一种移路径QoS路由协议,并给出了正确性验证及复杂性分析,并在NS2平台下对该改进后的协议进行了仿真实验和分析。仿真结果表明,该路由协议减少了路由重建数量,有效的增加了Ad Hoc网络的吞吐率,降低了延时从而有效地提高了网络性能。最后,对下一步改进工作也作简单介绍。     

不同负载下Ad Hoc网络路由协议的性能分析

本文首先介绍了几种典型的Ad Hoc网络路由协议和路由协议的性能评估,然后通过仿真对不同负载下常见路由协议的性能进行了分析,最后比较了两种不同网络负载分布下的 几种常见Ad Hoc网络路由协议的性能,得出了一些相关的结论,并对一些结论作了进一步的分析与说明。     

基于QualNet仿真软件的Ad Hoc路由协议的比较

本论文主要研究的是在QualNet网络仿真软件中比较Ad Hoc网络的两种路由协议:AODV和DSR。Ad Hoc网络是由一组带有无线收发装置的移动终端组成的一个多跳的临时性自治系统,因此,路由协议直接影响了Ad Hoc网络的工作状态及其性能水平。Ad Hoc路由协议主要分为表驱动路由协议和按需路由协议,AODV和DSR属于按需路由协议。本文在QualNet的平台上搭建了Ad Hoc网络模型,并就AODV和DSR这两种路由协议进行了网络仿真,包括不同网络负载情况下的路由协议收敛速度、分组发送成功率、网络吞吐量、端对端延时和抖动等参数指标,分析了两种路由协议的性能。     

Ad Hoc网络QoS多播路由协议

随着高性能网络、移动网络及Internet的不断发展，具有QoS约束的多播路由技术已成为网络及分布式系统领域的一个重要研究课题．该文研讨了Ad Hoc网络中具有Qos约束的多播路由问题，其中主要包含延迟、带宽、代价等Qos约束．文中描述了一种适应于研究Ad Hoc网络Qos多播路由的网络模型，提出了Ad Hoc网络中一种具有QoS约束的多播路由协议(QMRP)．文中给出了该协议的正确性证明和复杂性分析．仿真实验结果表明，该协议较其它协议更适合于网络状态变化比较频繁的环境以及实时多媒体应用，优化了多播树的代价．QMRP为Ad Hoc网络QoS约束多播路由提供了一种新的有效途径．     

浅析Ad Hoc网络路由协议

本文针对Ad Hoc网络的特点,阐述了Ad Hoc网络的路由协议设计的要求,本文简要介绍了Ad Hoc的三种典型路由协议,并使用网络模拟软件NS2对DSDV、DSR、AODV这三种典型路由协议进行了仿真,通过对仿真结果的分析比较三种协议的性能,分析各协议的不同适用范围和特性。     

基于NS2的Ad Hoc网络路由协议性能对比分析

移动Ad Hoc网络是移动节点动态临时组建的自组织网络,路由协议一直都是Ad Hoc网络研究的关键问题。使用NS2网络仿真软件,在不同的场景下分析比较移动Ad Hoc网络的5种路由协议DSDV、OLSR、DSR、AODV和TORA性能,得出不同路由协议在不同场景下的优缺点和适用的网络环境。     

Ad Hoc 网络中基于能量的 QoS 路由协议的研究

在 Ad Hoc 网络中,QoS 路由是提供 QoS 保证的一种重要手段.大多数 QoS 路由都是建立在单径的基础上,没有充分利用 Ad Hoc 网络资源.此外,网络中节点的能量也是影响网络性能的关键因素.然而,现有的 QoS 路由协议却很少考虑网络中节点能量有限这一问题.对此,文中在 DSR 路由协议的基础上提出一种基于能量约束的多径 QoS 路由协议(MPQE).该协议主要考虑带宽和剩余能量来选择多条 QoS 路由.仿真结果表明,MPQE 协议提高了吞吐率,降低了时延并延长了网络的生命周期     

Rethinking the architecture design of data center networks

In the rising tide of the Internet of things, more and more things in the world are connected to the Internet. Recently, data have kept growing at a rate more than four times of that expected in Moore’s law. This explosion of data comes from various sources such as mobile phones, video cameras and sensor networks, which often present multidimensional characteristics. The huge amount of data brings many challenges on the management, transportation, and processing IT infrastructures. To address these challenges, the state-of-art large scale data center networks have begun to provide cloud services that are increasingly prevalent. However, how to build a good data center remains an open challenge. Concurrently, the architecture design, which significantly affects the total performance, is of great research interest. This paper surveys advances in data center network design. In this paper we first introduce the upcoming trends in the data center industry. Then we review some popular design principles for today’s data center network architectures. In the third part, we present some up-to-date data center frameworks and make a comprehensive comparison of them. During the comparison, we observe that there is no so-called optimal data center and the design should be different referring to the data placement, replication, processing, and query processing. After that, several existing challenges and limitations are discussed. According to these observations, we point out some possible future research directions.     

Currents in connectionism

This paper reviews four significant advances on the feedforward architecture that has dominated discussions of connectionism. The first involves introducing modularity into networks by employing procedures whereby different networks learn to perform different components of a task, and a Gating Network determines which network is best equiped to respond to a given input. The second consists in the use of recurrent inputs whereby information from a previous cycle of processing is made available on later cycles. The third development involves developing compressed representations of strings in which there is no longer an explicit encoding of the components but where information about the structure of the original string can be recovered and so is present functionally. The final advance entails using connectionist learning procedures not just to change weights in networks but to change the patterns used as inputs to the network. These advances significantly increase the usefulness of connectionist networks for modeling human cognitive performance by, among other things, providing tools for explaining the productivity and systematicity of some mental activities, and developing representations that are sensitive to the content they are to represent.A version of this paper was the invited address at the first annual conference of the Society for Machines and Mentality in December, 1991. A related version was presented at the Computers and Philosophy Conference in August, 1992. I am extremely grateful to Adele Abrahamsen for her numerous suggestions and comments on various drafts of this paper.     

复杂网络聚类算法在生物网络中的应用

复杂网络在现实世界中普遍存在,具有小世界性和无标度性等统计特性,网络簇结构是复杂网络重要的拓扑属性之一。在复杂生物网络中使用聚类算法揭示生物网络中的簇结构对分析生物网络的拓扑结构、预测其功能都具有重要意义。对复杂网络聚类方法在蛋白质-蛋白质相互作用网络和新陈代谢网络中的应用及其进展情况进行了综述,分析了几种聚类算法的评价函数和适用条件,并对生物网络聚类算法研究所面临的主要问题进行了讨论。     

因子分解二终端网络可靠度近似计算

因子分解算法可以用来计算网络可靠度精确值,但对于大型网络,可靠度精确值的计算非常困难。基于时间和精确度的双重考虑,在精确算法的基础上通过改进得出一种近似算法。实验结果证明,该算法得到的近似值接近精确值,而且计算时间要低于精确算法。     

A middleware for industry

This paper describes an innovative distributed framework for monitoring and control of large-scale systems by integrating heterogeneous smart objects, the world of physical devices, sensors and actuators, legacy devices and sub-systems, cooperating to support holistic management [1]. Its featured Service Oriented Architecture (SOA) exposes objects’ capabilities by means of web services, thus supporting syntactic and semantic interoperability among different technologies, including SCADA systems [23]. Wireless Sensor and Actuator Network (WSAN) devices and legacy subsystems cooperate while orchestrated by a manager in charge of enforcing a distributed logic. Particularly crafted for industrial networks are new middleware services such as dynamic spectrum management, distributed control logic, object virtualization, WSANs gateways, a SCADA gateway service, and data fusion transport capability. In addition, new application oriented objects such as shop floor, manufacturing line, welding station, robots, and cells have been introduced in the middleware. The combination of such objects and previous modules offers a new and flexible industry oriented middleware. A second contribution is in the form of traffic analysis conducted at the floor level. It shows the dominance of some end systems such as PLCs, the presence well behaved almost constant traffic made up of small packets.     

A new routing algorithm for multirate rearrangeable Clos networks

In this paper, we study the problem of finding routing algorithms on the multirate rearrangeable Clos networks which use as few number of middle-stage switches as possible. We propose a new routing algorithm called the “grouping algorithm”. This is a simple algorithm which uses fewer middle-stage switches than all known strategies, given that the number of input-stage switches and output-stage switches are relatively small compared to the size of input and output switches. In particular, the grouping algorithm implies that m = 2n+(n−1)/2^k is a sufficient number of middle-stage switches for the symmetric three-stage Clos network C(n,m,r) to be multirate rearrangeable, where k is any positive integer and rn/(2^k−1).     

无线有组织网络

无线有组织网络是网络节点间有内在关系的无基础设施的无线网络,其除具有无基础设施无线网络的特征外,网络有中心节点,且节点位置关系相对固定。这种特殊的网络应用于野外救援、军事活动等临时性通信。首先回顾了对讲机系统、无线分组网络和无线自组织网络等无基础设施无线网络的结构和特点,它们都不能包涵无线有组织网络特征。详细定义了无线有组织网的相关模型,分析了无线有组织网络的特点和研究重点。     

神经网络控制结构及所用神经网络

本文阐述了神经网络控制所能解决的控制难题,若干种控制结构及常用的动态神经网络。讨论了神经网络控制研究的重点,在实时控制中的物理可实现性及其发展等问题。     

Banet — a local area network for distributed data processing

A broadcast architecture network (Banet) suitable for distributed data processing is proposed. One feature of Banet is that the broadcast-within-a-group function is supported not only by the datalink level but by the transport or session-level network structure. The commitment control scheme is included in the network protocol. Design goals, physical structure and protocols are discussed.     

多层前向小世界神经网络及其函数逼近

借鉴复杂网络的研究成果, 探讨一种在结构上处于规则和随机连接型神经网络之间的网络模型—-多层前向小世界神经网络. 首先对多层前向规则神经网络中的连接依重连概率p进行重连, 构建新的网络模型, 对其特征参数的分析表明, 当0 < p < 1时, 该网络在聚类系数上不同于Watts-Strogatz 模型; 其次用六元组模型对网络进行描述; 最后, 将不同p值下的小世界神经网络用于函数逼近, 仿真结果表明, 当p = 0:1时, 网络具有最优的逼近性能, 收敛性能对比试验也表明, 此时网络在收敛性能、逼近速度等指标上要优于同规模的规则网络和随机网络.