查询词典 network topology

The relationship between the topology and convegence of networks is approached and the reason causing overtraining and overfitting is analysed. Then the redundant weights and nodes in the network are defined by using improved activity function and a new algorithm called the BPNSO for determining the network structure for any application is proposed, which use dual optimization objective function combining the mean squre error of the network output with network complexity penalty function.

文章对网络拓扑结构与网络收敛性和稳定性的关系进行了探讨，分析了网络出现Overtraining或Overfitting的原因和解决的目标，提出了神经网络结构优化的策略，改进了活化函数，定义了冗余权值和冗余节点的概念，为辨识和删除冗余权值和冗余节点，提出采用优化目标函数中增加网络复杂度罚函数的双重优化目标函数，并对罚因子提出了基于学习误差和权值的自适应动态调整公式，论文定义了这种BP网络结构优化方法为BPNSO，并给出了完整的计算流程。

But above research were all based on network whose parameters and topology structure were determinate. Network system in practical circumstance often presents randomicity because of influence of some factors. So it often causes some errors when apply traditional network flow theory to practical problems. It is significant for improving network flow theory's practicability to optimize network flow in stochastic circumstance. This question has drawn attention.

但以上研究都是在网络参数和拓扑结构固定的网络上进行的优化，而实际环境中的网络系统受多种因素影响往往会表现出随机性，所以传统网络流理论在具体应用时与实际情况会有一定的偏差，如果能在随机环境下对网络流进行优化，对提高网络流理论的实用性和针对性均有重要意义，这个问题已越来越引起关注。

In this paper,taking the gas pipe network system as an example,the author analyzes the feature of geographical network,and gives the conceptual model of geographical network,deeply researches the establishment of the model of network data and the topology relation of gas pipe-network.

以城市燃气管网系统为例，在分析地理网络特征的基础上，提出了地理网络的概念模型，重点研究燃气管网数据模型和网络拓扑关系的构建。

The new model of innovation network is established based on breaker model, The identification of bus topology is converted into the identification of branch topology utilizing breaker model, and it can identify both bus topology change and branch topology change.

本文深化了新息图建模，提出了基于断路器建模的新息图法，得到了利用节点-支路模型辨识节点拓扑变化和支路拓扑变化的方法。

In this paper, typical physical topology and its characteristics of low-voltage network are analyzed in detail, topology model of power line communication over low-voltage network is given for simulation, and the means based on Ant Colony Optimization is put forward, which is used to construct the power line communication networks without any available information of power line wiring in a building On the basis of these, the effect and anti-destruction means are analyzed and tested by emulating experiments.

该文详细地分析了典型低压配电网物理拓扑结构和特点，给出了低压配电网通信仿真拓扑模型，提出了一种适用于未知建筑物电力线拓扑结构条件下的蚁群电力线组网方法；在此基础上，通过仿真试验验证了该组网路由算法的有效性和抗毁性。

We present a SNMP-based topology discovery algorithm using direct connection theorem and simple connection theorem for judging relationship of switches in subnets. In order to in discover the map of network without SNMP, several key problems such as subnet guessing and multi-address routers are discussed in details. And then a topology discovery algorithm based on primitive protocols is presented. We also deeply study some routing protocols such as OSPF and BGP and propose a routing-protocols-based algorithm for topology discovery.

基于判断交换机互联的直接连接定理和间接连接定理，提出了一种完整的基于SNMP的拓扑发现算法；详细讨论了子网获取、多址路由器处理等关键问题，针对不同的网络环境给出了相应的解决方案，并以此为基础提出了一种基于通用协议的拓扑发现算法；在对OSPF，BGP等网络路由协议进行分析的基础上给出了一种基于路由协议的拓扑发现算法，并设计了一个自上而下的拓扑发现框架结构。

People can get the current topology view through the browser expediently. We also allow user to review the history topology of any time of the history. Users can configure the standard topology of the network step by step.

用户可通过Web访问方式方便的查看当前网络的拓扑结构，实时了解网络的运行状况；也可以浏览任一历史时刻的网络拓扑结构，便于分析问题。

After this, users can compare the current topology view with standard topology view or any history topology view, this function would help users to discover the failure of the network expediently.

系统还提供了标准拓扑配置和拓扑间比较的功能，这都可以有效地提高系统的监控能力。

Hypercube has many advantages, such as smaller diameter, simple routing algorithm, many parallel paths between any two nodes, and fault-tolerance, on the other hand that the Hypercube nodal degree increased logarithmetically to the number of nodes has limited network population. So we propose a constant nodal degree hierarchical topology to remedy the weakness of Hypercube and take advantages of Hypercube most. Given the definition of FCCN we analyse the basic properties including nodal degree , number of links , extensibility and diameter (maximum network communication delay). Also we proposed a simple and self-routing algorithm applied in FCCN. Although the self-routing algorithm is not optimal, but at more than 82% case it can get the shortest path, and the percent is larger and larger increased with network levels. By the self-routing algorithm the internodal distance is calculated to evaluate the network communication delay more clearly. The average internal distance is in order of the cubic root of the network population that is almost same as logarithmetically relation in a few thousands. FCCN is a highly scalable network due to its recursive construction.

首先在比较了基本互连网络的基础上，看到超立体网络的杰出性能，包括网络直径小、寻路算法简单且为自寻路算法、容错能力好等等，但是由于其节点度随网络的规模的增加而按对数关系增长，使得超立体网络的应用规模受到极大限制，所以为了能最大限度利用超立体网络的优点的同时弥补其节点度方面的不足，作者提出了节点度等于常数4的FCCN网络结构，来最多地利用立方体网络的优点；然后在对FCCN网络进行严格的定义后，分析了网络的节点度、链路数、延伸特性、网络的直径（决定网络的最大通讯延迟）等，并提出了适于FCCN网络的简单的自寻路算法，计算自寻路算法可得到最短路径的比例，看到在多于82％以上的情况自寻路算法都是最优的，而且比例随网络层数的增加而增加；应用所提出的自寻路算法计算了可以更加准确反映网络通讯延迟的参数—网络平均节点距离，计算得到此参数与网络大小的立方根成正比，此比例关系在网络的规模在几千节点以内与对数关系的网络几乎一样；FCCN网络是一高度可扩展结构，这是因为FCCN的递归构成方式，使得网络在增加节点时其原有的拓扑结构可以保持不变，不需对网络进行重新设计，为网络的实用扩展提供了条件；理论分析得出FCCN网络是一种高度可扩展高性能网络的结论。

The network structure is significant in characterizing the performance of the feedforward network, such as network capacity, learning speed, generalization ability Standard back propagation performs gradient descent only in the weight space of a network with fixed topology, in general, it is useful only when the network architecture is chosen correctly With a bad structure we potentially run into problems like underfitting, overfitting or wasting computational resources, so algorithms than can find an appropriate network architecture automatically are highly attractive.

神经网络的结构对于前向网络的特性有重要的影响，如网络容量，学习速度，泛化能力等。标准BP算法是针对网络结构是固定的情况下搜索权值，一般来说，这只能在网络结构被正确选取才有用。如果网络结构不当，我们可能会欠拟合、过拟合或浪费计算资源，因此如果能找到能自动选取网络结构的算法是很有吸引力的。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。