A new generalized energy criterion for the passivity of digitalnetworks

A general passivity criterion for digital networks is introduced. Digital networks that meet this criterion form a stable and useful class of networks. The networks in this class have properties similar to passive analog networks. These networks are all stable, and some networks, including all linear networks, are shown to have restricted gain. The gain restriction can be used to design filters that are insensitive to changes in multiplier values at frequencies of maximum gain. Emerging directly from this criterion is a procedure for interconnecting simple networks to form a complex passive network. These networks remain stable after the introduction of rounding following multiplications so that these networks do not exhibit limit cycle oscillations     

电力系统区域网的分析与计算方法

本文在电网络理论的基础上,提出了一种分析计算大规模电力系统区域网的方法,文中首先应用网络分块结点抑制法推导出区域网等效结点电压方程式。然后,列举一个小规模的网络来说明应用这种方法计算的过程。这种方法适用于大规模电力系统区域网的计算．它可以减少计算工作量,提高计算速度。     

FBG传感网络技术研究

系统分析和总结了现有 FBG传感技术的复用结构和系统性能 ,并依据复用方式的频域、时域和空间特性 ,从网络拓扑结构的角度 ,提出把 FBG传感网络划分为波分复用网络、时分复用网络、空分复用网络、频分复用网络和混合复用网络 ,在此基础上比较了各种复用方式的优缺点 ,并针对网络实用化开发提出了自己的观点 ,从而为 FBO传感网络拓扑结构及性能的研究提供了参考。     

光学全交叉网络与全混洗网络之间的转换及实现

光学全交叉网络的快速控制需要在全混洗网络与光学全交叉网络间进行相互转换，本文分别给出了光学全交叉网络转换成全混洗网络及全混洗网络转换成光学全交叉网络时结点、链路、输入端口、输出端口的映射规则，并用电子学进行快速实现。     

论三网融合

讨论了电话网、计算机网、有线电视网三种网络的优势与不足,并提出实现宽带多媒体综合服务网的最佳途径：将有线电视网由单向广播式改造为双向交互式网络,进一步从技术和国家政策上讨论这个途径的可行性以及其社会意义。     

双口网络有效互连的判据和实现

一些功能不同的双口网络适当地连接在一起会实现某种特定的功能.双口网络间的连接方式有：串联、并联、串-并联、并-串联和级联.除级联方式外,其它互连方式都存在有效互连的问题,只有在有效连接的情况下,讨论双口网络的参数矩阵与各分双口网络参数矩阵的关系才有意义.以双口网络的串联连接为例,证明了双口网络有效互连与端口有效性检查互为充要条件的结论,并给出了当互连的双口网络不满足有效连接判据时如何实现有效连接.这对双口网络互连的教学具有一定的帮助.     

The latency/bandwidth tradeoff in gigabit networks

It is argued that delays through gigabit networks are dominated by propagation delay, so communications techniques and protocols for megabit networks would be inefficient or ineffective for gigabit networks. The latency-bandwidth tradeoff for gigabit networks is discussed, and an example of it is presented. It is concluded that gigabit networks have forced network designers to deal with propagation delays due to the finite speed of light     

泊松点过程下的一元MANET连接性分析

基于Boolean模型,对大规模的节点基于泊松点过程分布一元移动自组织网络的网络连接性进行了研究.从独立的移动自组织网络、提高某些节点功率的移动自组织网络和移动自组织网络与有线网络结合几种情况入手,对上述情况下的网络连接性进行了比较,得出了结合网络大大优于独立的移动自组织网络、提高节点功率的移动自组织网络性能优于独立的移动自组织网络的结论,为实际的Ad hoc组网提供了明确的评判依据.     

光学榕树网络与全混洗网络之间的转换及实现

光学榕树网络的快速控制需要在全混洗网络和光学植树网络间进行快速的相互转换．分别给出了光学榕树网络转换成全混洗网络及全混洗网络转换成光学植树网络时结点、链路、输入端口、输出端口的映射规则，并用电子学进行快速实现．     

FB-banyans and FB-delta networks: Fault-tolerant networks for broadband packet switching

Many fast packet switches for the broadband integrated services digital network (BISDN) in the literature are based on banyan networks. Although banyan networks possess nice properties such as a simple control and a low hardware cost, they are unique-path networks. Since there is a unique path from an input to an output in a banyan network, a single component failure may disrupt services of some nodes connected to such a network. Moreover, banyan networks are also blocking networks; packets can be lost within the networks. To reduce the packet loss, buffered banyan networks can be used. In an earlier work we have proposed the addition of backward links to otherwise unidirectional banyan networks to create B-banyans (and B-delta networks). Backward links not only function as implicit buffers for blocked packets, but also provide multiple paths for each input-output connection. However, the multiple paths in B-banyans may not be disjoint. In this paper, we enhance B-banyans and B-delta networks in such a way that the resulting networks can provide disjoint multiple paths for each input-output pair. The existence of disjoint multiple paths has a significant effect on the network fault-tolerance. The new networks, called FB-banyans and FB-delta networks, are k fault-tolerant, where k is the number of backward links per switch and is less than the switch size. They are also robust to more than k faults, depending on the locations of faults. The maximal fault-tolerance is achieved when k is the switch size minus 1. The performance of the new networks is analysed and compared to that of other networks of interest. FB-banyans and FB-delta networks can be used as a switch fabric for fast packet switches to provide performance comparable to that of buffered banyan networks and good fault tolerance.     

Network architecture for optical path transport networks

This paper proposes a new layered transport network architecture on which the WDM optical path network can be effectively created. The optical path network will play a key role in the development of the transport network that will realize the bandwidth-abundant B-ISDN. This paper extends the layered transport network architecture described in ITU-T Recommendation G.803 which is applied in existing SDH networks. First, we elucidate an application example of WDM optical path networks. Next, we propose a new layered architecture for WDM-based transport networks that retains maximum commonality with the layered architectures developed for existing B-ISDN networks. The proposed architecture is composed of circuit layer networks, electrical path layer networks, optical layer networks, and physical media (fiber) networks. The optical layer is divided into an optical path layer and an optical section layer. The optical path layer accommodates electrical paths. Optical section layer networks are divided into optical multiplex section (OMS) layer networks and optical repeater section (ORS) layer networks. The OMS layer network is concerned with the end-to-end transfer of information between locations transferring or terminating optical paths, whereas the ORS layer is concerned with the transfer of information between individual optical repeaters. Finally, a detailed functional block model of WDM optical path networks, the function allocation of each layer, and an optical transport module (OTM) are developed     

STABILITY CONTROL AND ANALYSIS OF ASYMMETRIC CONTINUOUS NEURAL NETWORKS

A new method for analyzing dynamics of continuous neural networks is proposed,and the necessary convergence conditions for a class of associative networks are obtained. Basedon the stability criterion and the equations of equilibrium set of the network, synthesis of aclass of associative neural networks is given. The stability control model of asymmetric unstablenetworks is suggested, which is also a valid way for optimization and dynamic control of stableneural networks.     

一种低噪放多级匹配网络的设计与仿真

匹配网络影响了低噪放的增益、噪声系数、带宽等重要指标。若采用单向设计,则输入与输出端匹配网络相互影响,使得匹配网络的性能下降,而常规双向设计需要对不同用途的匹配网络分别考虑,且设计繁琐。由此,本文提出了一种最佳阻抗匹配仿真法,它能较好地克服匹配网络间相互影响,对不同用途匹配网络不需分开设计,即可达到双向设计相同的目的,且设计过程简单直观,程序化,适合多级匹配网络的仿真设计。最后利用这种方法对2.49GHz高增益三级低噪放的各级匹配网络进行了设计。     

Fair Bandwidth Allocation in Optical Burst Switching Networks

Optical burst switching (OBS) is a promising switching technology for next-generation Internet backbone networks. One of the design challenges is how to provide fair bandwidth allocation in OBS networks; the schemes proposed for general store-and-forward IP switching networks can not be used because of the non-buffering and un-fully utilized bandwidth characteristics of OBS networks. We propose a rate fairness preemption (RFP) scheme to achieve approximately weighted max-min fair bandwidth allocation in OBS networks. We present an analysis of the burst loss probability in RFP-based OBS networks. The analysis and simulation results show that the RFP scheme provides fair bandwidth allocation in OBS networks.      

On the blocking performance of EGS networks under multicast traffic

Extended generalized shuffle (EGS) networks are a wide class of interconnection networks introduced by Richards (1993). In this work, we study the blocking performance of EGS networks under point-to-multipoint traffic. Two new routing algorithms for multicast connections in EGS networks are defined, and a theorem proving that these algorithms construct minimum-cost connection trees is enclosed. Simulation results show that the blocking performance of EGS networks under multicast traffic is much better than that of three-stage Clos networks of equal complexity     

GSM/GPRS网络向WCDMA网络的演进

国内现阶段的2G/2.5G网络已经越来越不能满足发展的需求,WCDMA作为第三代移动通信一种比较成熟的标准,被越来越多的人接受.如何从现有的GSM/GPRS网络向WCDMA网络平稳地过渡,如何尽量减少因新建网络带来的巨额成本,是每一个即将拿到3G牌照的运营商必须仔细考虑的问题.     

面向WIA-PA工业无线传感器网络的确定性调度算法

WIA-PA （Wireless Networks for Industrial Automation-Process Automation）是我国自主制定的工业无线传感器网络标准,确定性调度技术是其中一项关键技术.但目前已有的确定性调度算法主要集中在通用传感器网络或WirelessHART,ISA100.11a等遵循国外标准的工业无线传感器网络中,未能针对WIA-PA网络进行优化设计.鉴于此,本文提出了一种适用于WIA-PA网络的基于回溯法的最优确定性调度算法,能够获取调度解的最大成功率;并以此为基础,进一步提出了一种基于最小时间裕度优先的时分多址调度算法（Least Slack First on Time Division Multiple Access,LSF-TDMA）.仿真实验结果表明,所提出的LSF-TDMA算法能够满足WIA-PA网络端到端数据传输的确定性需求,在调度解获取成功率接近于最优的同时,有效降低了算法复杂度.     

Research on Performance of Complex Networks Based on Principal Component Analysis

For complex networks, their effectiveness and invulnerability are extremely important. With the development of complex networks, how to evaluate the effectiveness and invulnerability of these networks becomes an important research topic. The relationship among many influencing factors is very complicated, so it is essential to confirm the weighting coefficient of these influencing factors. Principal component analysis (PCA) is proposed to evaluate the performance of complex networks. It can improve one-sidedness of the single evaluation index and select different evaluation models according to different complex networks, which make the evaluation result more accurate. Performance of complex networks can be predicted according to comprehensive evaluation model. To verify the rationality and validity of this method, several small-world networks with different probability values and scale-free network are chosen to evaluate the network performance. Finally, simulation results show that PCA can be applied to performance evaluation of complex networks.     

A new concept-repackable networks

The following classes of connecting networks, based on their combinatorial properties, have been previously defined: networks nonblocking in the strict sense, networks nonblocking in the wide sense, rearrangeable networks, and blocking networks. To these the authors add the class of repackable networks, i.e., networks in which blocking can be avoided by using call repacking control algorithms. The conditions under which a three-stage Clos network is repackable are formulated and proved. The numbers of middle-stage switches in all network classes are compared, and the differences between repackable and rearrangeable networks are discussed     

非时隙CDMA分组网络吞吐量性能分析:统一的方法

CDMA分组网络性能主要受限于信道中同时传输的其它分组的干扰.与时隙CDMA分组网络相比,非时隙CDMA分组网络所受到的干扰情况更加复杂.本文提出了一种非时隙CDMA分组网络的干扰分析模型,并采用递归方式建立了网络吞吐量性能分析的统一方法.在此基础上,分析了网络节点突发固定长度分组和突发可变长度分组两种情况下的网络吞吐量性能,并讨论了扩频增益和分组传输方式对网络性能的影响,给出了相应的数值结果.文章最后进一步讨论了吞吐量的上下界问题.与前人提出的马尔可夫模型相比,采用本文提出的方法可以得到更为准确的吞吐量性能.