“三网合一”成真——重庆合川宽带综合信息网分析

很早,业界就喊着“三网合一”,事实上“三网合一”搞的并不怎么样。近来,宽带网络成为新宠,正和“三网合一”不谋而合,并且此类项目很牛,用户要建、厂商要赚,然而,究竟咋建,看看重庆合川的有线电视宽带网络如何使——     

三网融合助力网络新生活

三网融合,常常也被叫做“三网合一”,即互联网（数据通信网）、电信网（语音通信网）、广电网（广播电视网）合一。     

世纪之惑——百年IT未解决的问题

评说100年太玄乎了点,还要说100年的信息技术产业没有解决的问题,就更玄了。可不是嘛,100年前还没有信息技术这个词呢。不对,电话可有100多年的历史了吧,从有电话网到要与计算机网、有线电视网三网合一可是现在的事儿,对了,三网合一正在开始,三网合一可是表世纪没有解决的问题。回过头来还从“小”的问题开始。本世纪计     

无话费上Internet

在Internet日益红火的今天,相信你早已赶上了这趟快车。但是,你一定为上网的速度烦恼过。那么,你是不是梦想过享受专线的速度,建一个属于自己的网站,付出合理的费用呢?怎么样,心动了吧!跟我来,去看看三网合一给我们带来的福音——宽带高速信息网。 原理篇 所谓“三网”,指的是电话网、有线电视网、计算机的Internet网,目前中国的计算机网实际是架构在电话线上,而不是独立存在的,所以“三网合一”中的三网从物理结构上说,实际只有两网。由于我     

从Internet向SUPANET过渡实现“三网合一”

Internet是20世纪70年代末期出现的网络体系结构和技术，其体系结构与协议明显地打上了当时的通信技术水平（线路传输速率低、误码率高）和以文本传输为主的应用背景的烙印。DWDM技术的发展为实现“三纲合一”奠定了通信基础，但是Internet提供的“尽其所能”（Best Effort）服务无法保证未来实时图像数据、话音数据和文本数据集成服务的需要，不能以数字技术和分组交换技术实现“三网合一”。本文以笔者的研究工作为基础，以“三网合一”的需求和密集渡分复用（DWDM）技术为背景，讨论如何用“单物理层用户数据传输平台网络体系结构”（SUPA）及其核心吏挟技术——“类以大网物理帧时槽交换”（EPFTS）技术在骨干网上实现“三网合一”，又如何从Internet向SUPANET过渡。     

也谈三网合一

关于“三网合一”的定义是有争议的。一般认为,三网合一是指计算机网与电视网(含有线电视网)、电信网合而为一,并且合并的方向是传输、接收和处理全部实现数字化。现在更多谈论的是光纤到户(FiberToTheHome———FTTH),是指同时支持宽带上网、有线电视(CATV)接入和传统固定电话接入的三网合一。     

自动发现拓扑——菏泽建成三网合一的教育城域网

今年,菏泽市教育局提出了要汇聚菏泽地区教育网络资源,建设校校通工程。该工程以多服务体系为灵魂,电子教育为目的,满足社会对终身教育的需求。菏泽市教委希望采用一种可以融合语音、数据,视频于等高起点的“三网合一”网络。结合自身应用特点,菏泽教委最终选择了神州数码网络“三网合一”综合应用平台作为其网络一体化解决方案,尤其是采用神州数码全中文的LinkManager网络管理系统,可以自动发现网络拓扑结构,并通过仿真的设备面板     

门户危机何去何从

从投资趋势来看,如果宽带网发展起来,实现了三网合一,门户网站的位置就有可能被替代 互联网确实进入了最残酷阶段,按方兴东的说法“前一段是互联网企业股价挤泡沫的阶段,现在是互联网企业数量上挤泡沫的情况。”从投资趋势来看,如果宽带网发展起来,实现了三网合一,门户网站的位置就有可能     

甘肃白银“电子政府”以百姓为服务主体

在利用中国电信“全球眼”业务实现当地冶安、环保、城管“三网合一”综合管理系统之后,甘肃白银在此基础上将建设以百姓为服务主体的“白银市电子政府”。 在2008年年底成功地实现公安、环保、城管“三网合一”以后,白银市政府计划在今后的1～3年内,利用现代信息技术建成一个全面为民服务的“电子政府”,从而实现政府与群众信息资原共享利用的目标。     

六网合一

三网合一万口传,至今已觉不新鲜。而且,在绝大多数地方,三网尚未成功,服务仍需努力。在这种形势下,猫王首创“六网合一”之说,那是在百尺竿头,不只进了一步,还翻了个跟头。其实,猫王能提出六网合一这样的创见,主要是受了最近甚嚣尘上的四网合一论调的启发。所谓四网合一,指的是电力线上网。能上网传输数据,也就意味着能传语音、视频,再加上传电力,可不就是四网合一。现在当电力线上网吹鼓手的人不少,说得天花乱坠;但真要做起利弊分析来,响当当的好处也就一条——电力网分布极广,靠它上网不用重新     

A unified mathematical form for removing neurons based on orthogonal projection and crosswise propagation

It is a common practice to adjust the number of hidden neurons in training, and the removal of neurons in neural networks plays an indispensable role in this architecture manipulation. In this paper, a succinct and unified mathematical form is upgraded to the generic case for removing neurons based on orthogonal projection and crosswise propagation in a feedforward layer with different architectures of neural networks, and further developed for several neural networks with different architectures. For a trained neural network, the method is divided into three stages. In the first stage, the output vectors of the feedforward observation layer are classified to clusters. In the second stage, the orthogonal projection is performed to locate a neuron whose output vector can be approximated by the other output vectors in the same cluster with the least information loss. In the third stage, the previous located neuron is removed and the crosswise propagation is implemented in each cluster. On accomplishment of the three stages, the neural network with the pruned architecture is retrained. If the number of clusters is one, the method is degenerated into its special case with only one neuron being removed. The applications to different architectures of neural networks with an extension to the support vector machine are exemplified. The methodology supports in theory large-scale applications of neural networks in the real world. In addition, with minor modifications, the unified method is instructive in pruning other networks as far as they have similar network structure to the ones in this paper. It is concluded that the unified pruning method in this paper equips us an effective and powerful tool to simplify the architecture in neural networks.     

计算机环形局部网络的分类方法

本文提出了以时间和空间为参数对计算机环形局部网络进行分类的方法.其中时间和空 间各有三种分配方式,构成了一个既完备又互斥的系统,可以确切地对采用任何一种通讯协议 的环形局部网络进行分类. 作为例子,对迄今已报道的22个环形局部网络进行了分类.从而表明本分类方法是可行 的.     

Influences of variable scales and activation functions on the performances of multilayer feedforward neural networks

This paper gives insight into the methods about how to improve the learning capabilities of multilayer feedforward neural networks with linear basis functions in the case of limited number of patterns according to the basic principles of support vector machine (SVM), namely, about how to get the optimal separating hyperplanes. And furthermore, this paper analyses the characteristics of sigmoid-type activation functions, and investigates the influences of absolute sizes of variables on the convergence rate, classification ability and non-linear fitting accuracy of multilayer feedforward networks, and presents the way of how to select suitable activation functions. As a result, this proposed method effectively enhances the learning abilities of multilayer feedforward neural networks by introducing the sum-of-squares weight term into the networks’ error functions and appropriately enlarging the variable components with the help of the SVM theory. Finally, the effectiveness of the proposed method is verified through three classification examples as well as a non-linear mapping one.     

基于共享邻居数的社团结构发现算法

为了快速准确地找到复杂网络的社团结构,提出一种基于共享邻居数和局部模块度的社团结构发现算法。该方法通过不断寻找节点之间的共享邻居数找出与社团连接性最强的节点,并以局部模块度为衡量标准,判断是否将该节点加入到社团中。对3个典型复杂网络的划分结果表明,该算法是可行和有效的。     

Consensus networks with time-delays over finite fields

In this paper, we investigate the consensus problem in networks with time-delays over finite fields. The delays are categorised into three cases: single constant delay, multiple constant delays, and time-varying bounded delays. For all cases, some sufficient and necessary conditions for consensus are derived. Furthermore, assuming that the communication graph is strongly connected, some of the obtained necessary conditions reveal that the conditions for consensus with time-delays over finite fields depend not only on the diagonal entries but also on the off-diagonal entries, something that is intrinsically distinct from the case over real numbers (where having at least one nonzero diagonal entry is a sufficient and necessary condition to guarantee consensus). In addition, it is shown that delayed networks cannot achieve consensus when the interaction graph is a tree if the corresponding delay-free networks cannot reach consensus, which is consistent with the result over real numbers. As for average consensus, we show that it can never be achieved for delayed networks over finite fields, although it indeed can be reached under several conditions for delay-free networks over finite fields. Finally, networks with time-varying delays are discussed and one sufficient condition for consensus is presented by graph-theoretic method.     

Active RC realization of positive real axis transmission zeros using a differential-output amplifier†

A method of realizing exactly any real rational open-circuit voltage transfer function specification is given using three three-terminal RC networks and a differential-output amplifier. The method has the advantage that one of the three RC networks is required only when the specification has some positive real axis zeros.     

Welcome to convergence: surviving the next platform change [Internet protocol]

This article discusses the convergence of three components into an infrastructure based on the Internet protocol: voice, data, and wireless. In simple form, the converged Internet protocol (IP) platform has the three layers. At the bottom is the IP networks layer, which focuses on the secure, reliable, and efficient movement of bits using a variety of wireline and wireless networks residing in user and service provider (carrier) premises. The enterprise services layer uses the network and enables the applications. The applications layer provides business functions to the user by combining the underlying layers. Voice, data, and Internet on one platform threaten chaos, but those who keep cool and keep moving makes it.     

Efficient broadcasting in wormhole-routed multicomputers: anetwork-partitioning approach

In this paper, a network-partitioning approach for one-to-all broadcasting on wormhole-routed networks is proposed. To broadcast a message, the scheme works in three phases. First, a number of data-distributing networks (DDNs), which can work independently, are constructed. Then the message is evenly divided into submessages, each being sent to a representative node in one DDN. Second, the submessages are broadcast on the DDNs concurrently. Finally, a number of data-collecting networks (DCNs), which can work independently too, are constructed. Then, concurrently on each DCN, the submessages are collected and combined into the original message. Our approach, especially designed for wormhole-routed networks, is conceptually similar but fundamentally very different from the traditional approach of using multiple edge-disjoint spanning trees in parallel for broadcasting in store-and-forward networks. One interesting issue is on the definition of independent DDNs and DCNs, in the sense of wormhole routing. We show how to apply this approach to tori, meshes, and hypercubes. Thorough analyses and comparisons based on different system parameters and configurations are conducted. The results do confirm the advantage of our scheme, under various system parameters and conditions, over other existing broadcasting algorithms     

物流运输网络连通可靠性分析的高效分解算法

可靠性分析是衡量物流运输网络运行服务水平的主要手段之一。给出了一种评估物流运输网络连通可靠性的高效分解算法,算法充分利用分解过程中获得的相关信息,通过引入保持网络可靠性不变的串联边化简、并联边化简以及节点合并等规则,并结合向量集分解方法,能够快速实现对网络状态向量空间的分解,达到提高网络可靠性评估效率的目的。实例分析以及和现有方法的比较验证了算法的性能和分解效率。     

基于锚节点可部署性的无线传感器网络的定位算法

在实际应用中往往要求无线传感器网络提供节点位置信息,而节点定位算法的选择与很多因素有关,其中由于环境复杂程度及成本限制导致的锚节点可部署程度是很重要的客观因素之一.从锚节点可部署程度出发,提出了无线传感器网络的一种新的分类方法,系统地总结、阐述了锚节点分散部署于整个监测区域和只能部署于监测区域周围以及不能部署锚节点的3种网络可采用的代表性节点定位算法,并对3种网络的定位算法作了比较和评价.