Nonlinear Relationship and Its Evolutionary Trace between Node Degree and Average Path Length of China Aviation Network Based on Complex Network

In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the node degree and the average path length of China aviation network in 1988,1994,2001,2008 and 2015 was studied.According to the theory and method of complex network,the network system was constructed with the city where the airport was located as the network node and the airline as the edge of the network.On the basis of the statistical data,the node average path length of China aviation network in 1988,1994,2001,2008 and 2015 was calculated.Through regression analysis,it was found that the node degree had a logarithmic relationship with the average length of node path,and the two parameters of the logarithmic relationship had linear evolutionary trace.Key word:China aviation network,complex network,node degree,average length of node path,logarithmic relationship,evolutionary trace.

Nonlinear Relationship and Its Evolutionary Trace between Average Degree and Average Path Length of Edge Vertices of China Aviation Network Based on Complex Network

In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the average degree and the average path length of edge vertices of China aviation network in 1988,1994,2001,2008 and 2015 was studied.According to the theory and method of complex network,the network system was constructed with the city where the airport was located as the network node and the airline as the edge of the network.On the basis of the statistical data,the average degree and average path length of edge vertices of China aviation network in 1988,1994,2001,2008 and 2015 were calculated.Through regression analysis,it was found that the average degree had a logarithmic relationship with the average path length of edge vertices and the two parameters of the logarithmic relationship had linear evolutionary trace.

A Formula of Average Path Length for Unweighted Networks

In this paper,based on the adjacency matrix of the network and its powers,the formulas are derived for theshortest path and the average path length,and an effective algorithm is presented.Furthermore,an example is providedto demonstrate the proposed method.

Finding Multiple Length-Bounded Disjoint Paths in Wireless Sensor Networks

In a wireless sensor network, routing messages between two nodes s and t with multiple disjoint paths will increase the throughput, robustness and load balance of the network. The existing researches focus on finding multiple disjoint paths connecting s and t efficiently, but they do not consider length constraint of the paths. A too long path will be useless because of high latency and high packet loss rate. This paper deals with such a problem: given two nodes s and t in a sensor network, finding as many as possible disjoint paths connecting s and t whose lengths are no more than L, where L is the length bound set by the users. By now, we know that this problem is not only NP hard but also APX complete [1,2], which means that there is no PTAS for this problem. To the best of our knowledge, there is only one heuristic algorithm proposed for this problem [3], and it is not suitable for sensor network because it processes in a centralized way. This paper proposes an efficient distributed algorithm for this problem. By processing in a distributed way, the algorithm is very communication efficient. Simulation results show that our algorithm outperforms the existing algorithm in both aspects of found path number and communication efficiency.

Probability Distribution of Average Length of Node Path and Its Evolution Trace of Aviation Network of China Based on Complex Network

In order to reveal the complex network feature and its evolution principle of aviation network of China,probability distribution and its evolution trace of average length of node path of aviation network of China were researched according to statistics data in years 1988,1994,2001,2008 and 2015 of civil aviation of China.Floyd algorithm to calculate the path length between any two nodes of network was applied and average length of node path of aviation network was obtained according to this algorithm.It was discovered that average length of node path to other nodes had normal distribution function in each year.At meantime,the location parameter and scale parameter of normal distribution function had linear evolution trace.Airline rate was an index to describe the density of airline.It was found that average length of node path of aviation network of China evolved synchronously with airline rate and they had linear relationship.

A novel similarity measure for mining missing links in long-path networks

Network information mining is the study of the network topology,which may answer a large number of applicationbased questions towards the structural evolution and the function of a real system.The question can be related to how the real system evolves or how individuals interact with each other in social networks.Although the evolution of the real system may seem to be found regularly,capturing patterns on the whole process of evolution is not trivial.Link prediction is one of the most important technologies in network information mining,which can help us understand the evolution mechanism of real-life network.Link prediction aims to uncover missing links or quantify the likelihood of the emergence of nonexistent links from known network structures.Currently,widely existing methods of link prediction almost focus on short-path networks that usually have a myriad of close triangular structures.However,these algorithms on highly sparse or longpath networks have poor performance.Here,we propose a new index that is associated with the principles of structural equivalence and shortest path length(SESPL)to estimate the likelihood of link existence in long-path networks.Through a test of 548 real networks,we find that SESPL is more effective and efficient than other similarity-based predictors in long-path networks.Meanwhile,we also exploit the performance of SESPL predictor and of embedding-based approaches via machine learning techniques.The results show that the performance of SESPL can achieve a gain of 44.09%over GraphWave and 7.93%over Node2vec.Finally,according to the matrix of maximal information coefficient(MIC)between all the similarity-based predictors,SESPL is a new independent feature in the space of traditional similarity features.

Complex Networks: Traffic Dynamics, Network Performance, and Network Structure

This paper explores traffic dynamics and performance of complex networks. Complex networks of various structures are studied. We use node betweenness centrality, network polarization, and average path length to capture the structural characteristics of a network. Network throughput, delay, and packet loss are used as network performance measures. We investigate how internal traffic, through put, delay, and packet loss change as a function of packet generation rate, network structure, queue type, and queuing discipline through simulation. Three network states are classified. Further, our work reveals that the parameters chosen to reflect network structure, including node betweenness centrality, network polarization, and average path length, play important roles in different states of the underlying networks.

An Ideal Assortative Network and Synchronization

This paper proposes a novel complex network with assortative property based on multi-center networks. The average path length and clustering coefficient of the network are calculated, and the impact on the network topology is investigated. A simple dynamic system established on the proposed network is used to analyze how the assortative property of the network affects synchronization.

SFES: A scalable, fault-tolerant, efficient search scheme in a peer-to-peer network

This paper presents SFES: a scalable, fault-tolerant, efficient search scheme in a peer-to-peer network. The idea is based on the fact that data distribution in an information society has structured features. We designed an algorithm to cluster peers that have similar interests. When receiving a query request, a peer will preferentially forward it to another peer which belongs to the same cluster and shares more similar interests. By this method, search efficiency will be remarkably improved and at the same time good resistance against peer failure (the ability to withstand peer failure) is reserved. Keyword partial-match is supported, too.

Influence of Topological Properties of Complex Networks on the Effect of Spectral Coarse-Grained Network

Recently, some coarse-graining methods based on network synchronization have been proposed to reduce the network size while preserving the synchronizability of the original network. In this paper, we investigate the effects of the coarse graining process on synchronizability over complex networks under different average path lengths and different degrees of distribution. A large amount of experiments demonstrate a close correlation between the average path length, the heterogeneity of the degree distribution and the ability of spectral coarse-grained scheme in preserving the network synchronizability. We find that synchronizability can be well preserved in spectral coarse-grained networks when the considered networks have a longer average path length or a larger degree of variance.

Terrain Details Effect on Connectivity in Ad hoc Wireless Networks

In this work, we conduct a research on the effects of the details of the terrain on the path establishment in wireless networks. We discuss how the terrain induced variations, that are unavoidably caused by the obstructions and irregularities in the surroundings of the transmitting and the receiving antennas, have two distinct effects on the network. Firstly, they reduce the amount of links in the network connectivity graph causing it to behave more randomly, while decreasing the coverage and capacity of the network. Secondly, they increase the length of the established paths between the nodes. The presented results show how the terrain oblique influences the layout of the network connectivity graph, in terms of different network metrics, and gives insight to the appropriate level of details needed to describe the terrain in order to obtain results that will be satisfyingly accurate.

On the Dynamical Analysis in Aftershock Networks

We investigate the dynamical behavior of aftershocks in earthquake networks, and the earthquake network calculated from a time series is constructed by contemplating cell resolution and temporal causality. We attempt to connect an earthquake network using relationship between one main earthquake and its aftershocks from seismic data of California. We mainly examine some topological properties of the earthquake such as the degree distribution, the characteristic path length, the clustering coefficient, and the global efficiency. Our result cannot presently determine the universal scaling exponents in statistical quantities, but the topological properties may be inferred to advance and improve by implementing the method and its technique of networks. Particularly, it may be dealt with a network issue of convenience and of importance in the case how large networks construct in time to proceed on earthquake systems.

Data Transmission Reliability of a Two-source Single-sink Computer Network with a Common Arc

在一个多状态网络(MSN ) ，数据能通过不同路径被播送。以前的文学与路径在有一条普通的弧的弧拆散路径，然而并非盒子集中于盒子。在这个工作，我们认为盒子是节点通过他们的自己的最小的路径(MP ) 正在送数据到水池节点的二来源，在这二 MP 在计算机网络拥有一条普通的弧的地方。每个来源节点产生一个数据序列。产生数据的时间间隔是随机分布式的。另外，在不同时间片刻产生的数据的数量是随机分布式的。这二个变量能被 Monte-Carlo 模拟方法获得。当所有数据通过一条普通的弧被播送，用弧和 conflictions 为优先级竞争的数据需要可以被引起。我们在他们的传播时间限制下面认为二 MP 在连接并且计算的盒子是数据的可靠性。模拟结果表明 conflictions 能延长他们的传播时间并且因此影响他们的可靠性。这个工作可以提供相互参照让经理决定数据和时间间隔的数量得到理想的网络可靠性。

Development of Global Geographical Coverage Area for Terrestrial Networks Internetworked with Leo Satellite Network

Network planning, analysis and design are an iterative process aimed at ensuring that a new network service meets the needs of subscribers and operators. During the initial start-up phase, coverage is the big issue and coverage in telecommunications systems is related to the service area where a bare minimum access in the wireless network is possible. In order to guarantee visibility of at least one satellite above a certain satellite elevation, more satellites are required in the constellation to provide Global network services. Hence, the aim of this paper is to develop wide area network coverage for sparsely distributed earth stations in the world. A hybrid geometrical topology model using spherical coordinate framework was devised to provide wide area network coverage for sparsely distributed earth stations in the world. This topology model ensures Global satellite continuous network coverage for terrestrial networks. A computation of path lengths between any two satellites put in place to provide network services to selected cities in the world was carried out. A consideration of a suitable routing decision mechanism, routing protocols and algorithms were considered in the work while the shortest paths as well as the alternate paths between located nodes were computed. It was observed that a particular satellite with the central angle of 27°can provide services into the diameter of the instantaneous coverage distance of 4081.3 Km which is typical of wide area network coverage. This implies that link-state database routing scheme can be applied, continuous global geographical coverage with minimum span, minimum traffic pattern and latency are guaranteed. Traffic handover rerouting strategies need further research. Also, traffic engineering resources such as channel capacity and bandwidth utilization schemes need to be investigated. Satellite ATM network architecture will benefit and needs further study.

基于空间句法的矿井应急疏散研究与应用

地下矿井作业危险,空间拓扑结构复杂,因而矿山安全事故时有发生,合理的应急疏散路线规划以及疏散指示布置,能够有效提高井下人员的逃生效率,降低人员伤亡与财产损失。结合某地下矿井实例,基于空间句法和GIS网络分析搭建地下矿井巷道网络模型,从逃生人员的空间认知角度出发,利用标准化角度选择度值选取巷道网络模型中的前景网络和背景网络作为主要避险通道,为应急疏散指示标志布置提供参考;考虑巷道宽度、巷道类型、巷道坡度等巷道基础属性信息,并结合空间句法指标——标准化角度整合度,构建巷道网络应急脆弱模型,顾及巷道空间单元的稳定性,规划井下人员的最优认知路径,进而实现了多目标的地下矿井紧急疏散路线规划。该研究不仅能够为地下矿井的巷道布局设计提供建议,还可为地下矿井的应急疏散路线规划辅助决策、应急预案制定提供理论依据,同时为紧急避险系统的建设与完善提供新的思路。

含网络攻击的智能网联汽车路径跟踪状态估计与控制

智能网联汽车具有信息物理系统(Cyber-physical systems, CPS)的特征,运行中容易受到网络攻击的不利影响,造成通信数据的异常交互,降低行车安全。建立智能网联汽车路径跟踪动力学模型和两自由度汽车操纵动力学模型,分析车辆路径跟踪控制系统信息架构,考虑系统响应存在网络攻击,将连续系统状态空间方程进行离散化处理。根据线性二次估计设计一种递归状态估计器。仿真研究网络攻击对智能网联汽车路径跟踪的影响,状态估计器对网络攻击下车辆路径跟踪控制的效果及鲁棒性。结果表明:网络攻击会导致智能网联汽车路径跟踪效果变差,验证了状态估计器能够有效改善网络攻击对车辆跟踪控制的不利影响,且当网络攻击程度λ、协方差P初值的不同,状态估计器表现出较好的鲁棒性。本研究能够保证网络攻击下智能网联汽车数据信息的可靠交互,有利于改善智能网联汽车跟踪行驶的性能。

PATH PROBLEM SIMPLIFICATION WITH DESIRED BOUNDED LENGTHS IN ACYCLIC NETWORKS

Path determination is a fundamental problem of operations research. Current solutions mainly focus on the shortest and longest paths. We consider a more generalized problem; specifically, we consider the path problem with desired bounded lengths （DBL path problem）. This problem has extensive applications; however, this problem is much harder, especially for large-scale problems. An effective approach to this problem is equivalent simplification. We focus on simplifying the problem in acyclic networks and creating a path length model that simplifies relationships between various path lengths. Based on this model, we design polynomial algorithms to compute the shortest, longest, second shortest, and second longest paths that traverse any arc. Furthermore, we design a polynomial algorithm for the equivalent simplification of the is O（m）, where m is the number of arcs. DBL path problem. The complexity of the algorithm

青岛市湿地生态网络评价与构建

在快速城市化背景下,城市社会经济发展与空间扩张不可避免,往往造成栖息地数量、面积、质量锐减、栖息地之间联系破碎等后果。此外,全球气候变化也加剧了栖息地恶化过程。生态网络通过保护恢复重点栖息地及构建栖息地之间物质、信息及能量传播的连接廊道,在整体上维持生态系统的动态平衡。青岛市位于东部沿海经济发达地区,地处海洋与陆地生态系统的交汇处,生态环境极为脆弱,易遭受外力破坏,且难以恢复。选取青岛地区湿地作为研究对象,在RS,GIS技术支持下,基于最小成本路径法构建青岛市湿地生态网络,并利用关联长度指数、介数指数对网络的整体结构及斑块重要程度进行评价。结果表明,不同路径成本阈值水平下,网络的连通性有很大差别;核心斑块中,胶州湾湿地、大沽河等具有较高重要程度;歇脚石斑块中,重要程度较高的斑块位于以胶州湾湿地为中心,以胶莱河、潍河河口,白马河、潮河河口及丁字湾为端点的连线上。在青岛市及周边地区划定"一心、二轴、一环"的湿地生态网络控制框架的策略,为青岛市湿地生态系统保护与城市发展空间选择提供科学方法与量化依据。

城市道路网络的小世界特征研究

小世界模型为研究城市道路网络的拓扑结构和内在特征等提供了新的视角和方法。该文采用原始法(primalapproach)对城市道路网络进行适度抽象,利用ArcGIS 9.0和Matlab 7.0分别处理和计算城市道路网络的空间数据和属性数据,进而探索其小世界特征。以无锡市新区为例,研究该区整体城市道路网络的小世界特征,选取特征各异的局部网络,并对其小世界特征进行比较分析。结果表明,无锡市新区城市道路网络具有较小的特征路径长度和较大的聚类系数,为典型的小世界网络;局部道路网络均具有小世界特征,其显著程度与道路网络的空间结构特征具有一定相关性;疏密适宜的道路网络具有突出的小世界特征,是规划布局的可行方向,可为城市道路网络优化提供指导。