包含立交匝道信息的高速公路网络复杂拓扑结构

在以往的路网拓扑研究中,立交和出入口一般都只被看成一个节点来处理,没有涉及具体的匝道信息,但随着路网规模的扩大及基于路网拓扑的安全性分析、通达性研究、交通标志设置、紧急情况处置、模拟仿真和车辆导航等需求的不断增加,原来单层结构的拓扑关系已经不能满足这些应用要求,另一方面,由于原来路网拓扑结构相对比较简单,导致相应的最佳路径搜寻算法都很复杂.在总结已完成项目的基础上,从交通工程角度研究了一种包含具体匝道信息的多层次高速公路路网复杂拓扑结构,包含路段/节点、匝道/出入口、方向节点等内容,满足地理数据文件(GDF)标准格式要求,可支持新一代基于复杂路网结构的多种应用,采用双向链表建立的数据结构,方便增减高速公路、立交或者出入口等对象,在此基础上研究了一种适应复杂路网架构的路径搜索算法,为基于所提出的复杂路网拓扑应用提供了可能.     

面向交通安全管控的高速公路基础路网模型及其应用

从满足高速公路交通安全联网联控对路网模型的精细化需求角度分析了路网建模的要点,提出了一种适合高速公路路网数据表达、操作的高速公路基础路网数据模型。该模型基于分层拓扑组织路网要素,以里程桩号作为路网建模划分的最小粒度,同时包含车道信息,可根据不同需求组合为抽象路网。模型包含有向路段、有向路段结点、有向子路段、有向子路段结点、车道、车道连接器六个部分,能够细致的描述高速公路路网拓扑结构。选取沈海高速与沪陕高速共用路段区域路网作为试验区域,建立了基于该模型的高速公路路网数据库,并将模型应用于高速公路突发事件处理,实例表明该模型有利于迅速响应高速公路网络的突发事件,满足高速公路交通安全联网联控相关应用对路网模型的需求。     

道路网络中门到门包含重复节点的最优路径算法

设计了用于包含交通约束的受限路网中基于兴趣点(PO I)的门到门包含重复节点的寻路算法。首先利用距离最短准则建立PO I和路网间的临时拓扑关系,然后根据受限路网中最优路径的结构特征,构造包含驶入路段的节点进行寻路拓展,以此为基础进行标记设定广度优先搜索,即可获得门到门包含重复节点的最优路径。在道路密度较大的北京市路网中的试验结果表明,该算法能够根据交通约束规划出实用的最优路径,对于长度约60 km路径的计算平均耗时在3 s左右,可以满足车辆导航应用的实时性要求。     

道路网络中门到门包含重复节点的最优路径算法

设计了具有交通约束的受限路网中,基于兴趣点(POI)的门到门包含重复节点的寻路算法。该算法首先利用距离最短准则建立POI和路网间的临时拓扑关系,然后根据受限路网中最优路径的结构特征,构造包含驶入路段的节点进行寻路拓展,以此为基础进行标记设定广度优先搜索,即可获得门到门包含重复节点的最优路径。在道路密度较大的北京市路网中的试验结果表明,该算法能够根据交通约束规划出实用的最优路径,对于长度约60km路径的计算平均耗时在3s左右,可以满足车辆导航应用的实时性要求。     

常州市长虹路-青洋路立交方案比选与设计

长虹路—青洋路立交是常州市重要的对外交通出入口,根据其所处地理位置,确立了采用全互通立交形式、主要流向交通快速通过、次要流向交通通行顺畅、立交层数不宜过多的设计原则,并以此原则进行了方案的比选和具体设计,以满足城市快速路网对该节点的交通功能需求。     

高速公路互通式立体交叉设计

互通式立体交叉公路是高速公路网的主要节点,高速公路互通式立交的选型关系对路网功能作用的发挥起着关键的作用。互通的选型应满足路网规划的要求,同时其位置和型式亦是高速公路路线走向的一个重要制约因素。     

互通式立交如何选型

互通式立体交叉公路是高速公路网的主要节点,高速公路互通式立交的选型关系对路网功能作用的发挥起着关键的作用。互通的选型应满足路网规划的要求,同时其位置和型式亦是高速公路路线走向的一个重要制约因素。     

广州西二环高速桃园立交方案设计

本文分析了桃园互通立交在路网中地位、转向交通量、匝道布设等方面的特点,提出了多个立交方案的比选,最终选择经济、合理的立交方案,总结出市郊高速公路互通式立交方案设计的主要影响因素。     

城市主干道路网的复杂网络特性

以复杂网络理论为基础,把复杂网络与城市交通网络结合,研究城市主干路网的空间拓扑结构以及路网结构特性.以大连市主干路网为例,通过Ucinet计算城市主干路网的节点度、聚类系数、平均路径长度、网络效能等基本参数并绘制图表分析;最后根据去除节点的聚类系数、平均路径长度、网络效能的计算,对大连市路网整体结构进行分析.结果可以看出,大连市主干路网是一个典型的小世界网络,但不具有无标度特性;节点度越大对整个城市路网影响大,对路网稳定性、连通性以及路网效率有着直接的影响.     

城市互通立交设计与施工

互通立交是城市快速路网中的关键节点,互通立交设计应从标准与规模、立交形态和匝道设计速度三方面加以考虑。在施工方案中重点控制现浇架搭设、预应力钢筋张拉、混凝土铺装和伸缩缝施工等环节。     

复杂网络抗毁性研究进展

随着复杂网络研究的兴起,复杂网络抗毁性研究的重大理论意义和应用价值日益突显出来,成为极其重要而且富有挑战性的前沿科研课题.本文总结综述了国防科技大学信息系统与管理学院在复杂网络抗毁性领域取得的研究进展,具体包括:研究了不完全信息条件下复杂网络拓扑结构抗毁性;提出了复杂网络拓扑结构抗毁性的谱测度方法;分析了3种结构属性对复杂网络拓扑结构抗毁性的影响;提出了基于禁忌搜索的复杂网络拓扑结构抗毁性仿真优化方法.     

带有多个时变时滞的二阶网络的一致性算法

研究了二阶动态无向网络的一致性问题,其采用的协议既考虑了时滞,又考虑了网络拓扑结构发生切换的影响.通过分析发现,当网络受到多个时变时滞或者同时受到网络拓扑结构发生切换的影响时,在一定条件下,该无向网络能实现一致.另外在频率域里,还求出了任意两个不同自主体之间通信所允许的一个共同时滞上界.这个上界是依赖于网络参数的,因此具有更低的保守性.     

Relay switched, scalable topology control for mobile robot networks based on motion synchronization

A mobile robot network is said to be easily scalable to any number of robots if its performance is kept almost fixed after these robots are added or some fail in the network. An interaction dynamics model based on motion synchronization is first established. Considering the mobility of mobile robot networks, we propose a relay switched, distributed topology control for the scalable network to drive newly added robots to the most suitable positions with more neighbors as well as self-heal the blank positions of failed robots, and give a metric of the topology structure for evaluating the performance of network topologies. Then, we prove the stability of motion synchronization with the individual control based on Lyapunov exponent. Finally, the results of simulations have demonstrated the validity of the proposed modeling and control methods.     

复杂系统在城市交通网络中的应用

 面对日益严重的城市交通问题,分析和研究城市交通复杂网络的特性,对解决城市交通相关问题和合理规划城市布局具有十分重要的实际意义。本文首先介绍了复杂系统相关理论知识,包括复杂系统研究中常用的几种统计特性和不同拓扑结构下的复杂网络的发展历程;然后从交通流问题、不同拓扑结构对交通网络的影响、网络中心节点、级联失效现象和网络稳定性5个方面分析了复杂网络在城市交通系统中的应用;最后对复杂系统在城市交通网络中的未来研究方向和发展趋势进行了展望。     

计算机网络模型中的复杂性现象分析

基于 Transit- Stub分层网络拓扑结构模型 ,提出了一个相对复杂的计算机网络模型 ,并通过对仿真结果的处理 ,揭示并分析了其中存在的诸如相变、幂率等复杂性现象 ,同时定性地研究了网络参数的影响。研究发现 ,网络的规模和带宽以及用户行为的统计分布都将对网络的相变现象有着重要的影响 ,数据流分布和节点排队长度的功率谱分布都呈现出幂率的特征。研究结果表明 :网络带宽的增加有助于抑制拥塞相变带来的影响 ,频域中的幂率现象说明了网络中存在的长相关特性     

High-Performance Broadcasting Algorithms on Cluster

In many clusters connected by high-speed communication networks, the exact structure of the underlying communication network and the latency difference between different sending and receiving pairs may be ignored when they broadcast, such as in the approach adopted by the broadcasting method in MPICH，a widely used MPI implementation. However, the underlying network cluster topologies are becoming more and more complicated and the performance of traditional broadcasting algorithms, such as MPICH‘s MPI_Bcast, is far from good. This paper analyzed the impact of communication latencies and the underlying topologies on the performance of broadcasting algorithms for multilevel clusters. A multilevel model was developed for broadcasting in clusters with complicated topologies, which divides the cluster topology into many levels based on the underlying topology. The multilevel model was used to develop a new broadcast algorithm，MLM broadcast-2 (MLMB-2), that adapts to a wide range of clusters. Comparison of the performance of the counterpart MPI operation MPI_Bcast and MLMB-2 shows that MLMB-2 outperforms MPI_Bcast by decreasing the broadcast running time by 60%-90%.     

MW-OBS： An Improved Pruning Method for Topology Design of Neural Networks

Introduction Artificial neural networks(ANNs)have been widely used in many areas in recent years.In practical prob-lems,the first step of a typical ANN applying process is to design the neural network structure,including the number of layers,the number of…     

基于复杂网络理论的Internet拓扑节点特征分析

基于复杂网络理论对Internet的IP级拓扑中的节点特征进行了分析。阐述了复杂网络理论中节点度、度相关性、聚集系数等特征的概念。采用由skitter和fastrace实际测量得到的四幅拓扑,提取其复杂网络特征,并进行了比较分析。     

Design principles of a bacterial signalling network

Cellular biochemical networks have to function in a noisy environment using imperfect components. In particular, networks involved in gene regulation or signal transduction allow only for small output tolerances, and the underlying network structures can be expected to have undergone evolution for inherent robustness against perturbations. Here we combine theoretical and experimental analyses to investigate an optimal design for the signalling network of bacterial chemotaxis, one of the most thoroughly studied signalling networks in biology. We experimentally determine the extent of intercellular variations in the expression levels of chemotaxis proteins and use computer simulations to quantify the robustness of several hypothetical chemotaxis pathway topologies to such gene expression noise. We demonstrate that among these topologies the experimentally established chemotaxis network of Escherichia coli has the smallest sufficiently robust network structure, allowing accurate chemotactic response for almost all individuals within a population. Our results suggest that this pathway has evolved to show an optimal chemotactic performance while minimizing the cost of resources associated with high levels of protein expression. Moreover, the underlying topological design principles compensating for intercellular variations seem to be highly conserved among bacterial chemosensory systems.     

Reliability Analysis of Sensor Networks

To Integrate the capacity of sensing, communication, computing, and actuating, one of the compelling technological advances of these years has been the appearance of distributed wireless sensor network （DSN） for information gathering tasks. In order to save the energy, multi-hop routing between the sensor nodes and the sink node is necessary because of limited resource. In addition, the unpredictable conditional factors make the sensor nodes unreliable. In this paper, the reliability of routing designed for sensor network and some dependability issues of DSN, such as MTTF （mean time to failure） and the probability of connectivity between the sensor nodes and the sink node are analyzed. Unfortunately, we could not obtain the accurate result for the arbitrary network topology, which is # P-hard problem. And the reliability analysis of restricted topologies clustering-based is given. The method proposed in this paper will show us a constructive idea about how to place energyconstrained sensor nodes in the network efficiently from the prospective of reliability.