scholarly journals Complex Network Theory for Water Distribution Networks Analysis

10.29007/w1bk ◽  
2018 ◽  
Author(s):  
Antonietta Simone ◽  
Luca Ridolfi ◽  
Luigi Berardi ◽  
Daniele Laucelli ◽  
Orazio Giustolisi
Keyword(s):  
Complex Network ◽  
Network Theory ◽  
Path Length ◽  
Water Distribution ◽  
Distribution Networks ◽  
Networked Systems ◽  
Clustering Coefficient ◽  
Complex Network Theory ◽  
Connectivity Structure

Performance of networked systems greatly depends on their topologic or connectivity structure. Nowadays, the analysis of the relevant features influencing the emerging behavior of networked systems is possible because of the increasing computational power and availability of information. Complex Network Theory classifies the connectivity structures of real systems using the nodal degree, the average path length, the clustering coefficient and the probability of connection. However, networked city infrastructures, e.g. water distribution networks (WDNs), are constrained by the spatial characteristics of the environment where they are laid. Therefore, networked infrastructures are classified as spatial networks and the classification of their connectivity structure requires a modification of the classic framework. To this purpose, the paper proposes a classification of WDNs using the neighbourhood nodal degree instead of the classic degree, the network size instead of the probability of connection and the classic average path length. The research will show that the clustering coefficient is not useful to describe the behavior of these constrained systems.

Research on the Structure of Peer-to-Peer Overlay Based on the Complex Network Theory

2012 ◽  
Vol 263-266 ◽  
pp. 1096-1099
Author(s):  
Zhi Yong Jiang
Keyword(s):  
Complex Network ◽  
Network Theory ◽  
Degree Distribution ◽  
Path Length ◽  
Small World ◽  
Peer To Peer ◽  
Clustering Coefficient ◽  
Power Law Distribution ◽  
Complex Network Theory ◽  
The Mean

Relationship between nodes in peer-to-peer overlay, currently becomes a hot topic in the field of complex network. In this paper a model of peer-to-peer overlay was purposed. And then the paper focused on figuring out the mean-shortest path length (MSPL), clustering coefficient (CC) and the degree of every node which allowed us to discover the degree distribution. The results show that the degree distribution function follows approximately power law distribution and the network possesses notable clustering and small-world properties.

scholarly journals Centrality Metrics for Water Distribution Networks

10.29007/7lxd ◽  
2018 ◽  
Author(s):  
Antonietta Simone ◽  
Luca Ridolfi ◽  
Daniele Laucelli ◽  
Luigi Berardi ◽  
Orazio Giustolisi
Keyword(s):  
Network Theory ◽  
Water Distribution ◽  
Distribution Networks ◽  
Point Of View ◽  
Networked Systems ◽  
Water Distribution Networks ◽  
Physical Systems ◽  
Complex Network Theory ◽  
Infrastructure Networks ◽  
Centrality Metrics

Complex Network Theory (CNT) studies theoretical and physical systems as networks, considering their features deriving from the internal connectivity between elements defined as vertex and links. In order to quantify the importance of these elements in real networked systems, researches proposed several centrality metrics.The use of CNT centrality metrics for analysis, planning and management of infrastructure networks (streets, water systems, etc.), for example in terms of reliability and vulnerability, is today a relevant issue also considering their influences in socio- economics and environmental matters. From CNT standpoint, water distribution networks (WDNs) are infrastructure networks that can be analyzed considering some peculiar features deriving from their spatial characteristics.The paper focuses on CNT centrality metrics and proposes novel hydraulic centrality metrics useful for understanding the WDNs behavior. Furthermore, the study is intended to evaluate the feasibility of coupling hydraulic and topologic centrality metrics based on links, in order to obtain information that are more useful from the hydraulic point of view. This way, centrality metrics of the CNT become a complementary tool to hydraulic modelling for WDNs analysis and management.

scholarly journals Urban Transit Network Properties Evaluation and Optimization Based on Complex Network Theory

2019 ◽  
Vol 11 (7) ◽  
pp. 2007 ◽  
Author(s):  
Guo-Ling Jia ◽  
Rong-Guo Ma ◽  
Zhi-Hua Hu
Keyword(s):  
Complex Network ◽  
Network Theory ◽  
Public Transportation ◽  
Path Length ◽  
Transportation Network ◽  
Average Path Length ◽  
Theory And Practice ◽  
Complex Network Theory ◽  
Public Transportation Network ◽  
Bus Network

Urban public transportation contributes greatly to sustainable urban development. An urban public transportation network is a complex system. It is meaningful for theory and practice to analyze the topological structure of an urban public transportation network and explore the spatial structure of an urban transportation network so as to mitigate and prevent traffic congestion and achieve sustainability. By examining the Xi’an bus network, the degree distribution, average path length, aggregation coefficient, and betweenness centrality of the bus station network were computed using models in complex network theory. The results show that the node degrees of the Xi’an bus network are unevenly distributed and present a polarization diagram with long average path length and high aggregation. A model based on betweenness and its solution method was developed to improve the public transportation network’s sustainability and discuss the possibility of optimizing the sustainability by network analyzing methods.

scholarly journals Classification of Literary Works: Fractality and Complexity of the Narrative, Essay, and Research Article

Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 904
Author(s):  
Aldo Ramirez-Arellano
Keyword(s):  
Complex Network ◽  
Path Length ◽  
Research Topic ◽  
Clustering Coefficient ◽  
Node Degree ◽  
Original Text ◽  
Literary Works ◽  
Research Article ◽  
A Current

A complex network as an abstraction of a language system has attracted much attention during the last decade. Linguistic typological research using quantitative measures is a current research topic based on the complex network approach. This research aims at showing the node degree, betweenness, shortest path length, clustering coefficient, and nearest neighbourhoods’ degree, as well as more complex measures such as: the fractal dimension, the complexity of a given network, the Area Under Box-covering, and the Area Under the Robustness Curve. The literary works of Mexican writers were classify according to their genre. Precisely 87% of the full word co-occurrence networks were classified as a fractal. Also, empirical evidence is presented that supports the conjecture that lemmatisation of the original text is a renormalisation process of the networks that preserve their fractal property and reveal stylistic attributes by genre.

scholarly journals Complex network theory, streamflow, and hydrometric monitoring system design

2015 ◽  
Vol 19 (7) ◽  
pp. 3301-3318 ◽  
Author(s):  
M. J. Halverson ◽  
S. W. Fleming
Keyword(s):  
Complex Network ◽  
Network Theory ◽  
Small World ◽  
Detection Algorithm ◽  
Clustering Coefficient ◽  
Network Stability ◽  
Meteorological Forcing ◽  
Complex Network Theory ◽  
Scale Free ◽  
Seasonal Flow

Abstract. Network theory is applied to an array of streamflow gauges located in the Coast Mountains of British Columbia (BC) and Yukon, Canada. The goal of the analysis is to assess whether insights from this branch of mathematical graph theory can be meaningfully applied to hydrometric data, and, more specifically, whether it may help guide decisions concerning stream gauge placement so that the full complexity of the regional hydrology is efficiently captured. The streamflow data, when represented as a complex network, have a global clustering coefficient and average shortest path length consistent with small-world networks, which are a class of stable and efficient networks common in nature, but the observed degree distribution did not clearly indicate a scale-free network. Stability helps ensure that the network is robust to the loss of nodes; in the context of a streamflow network, stability is interpreted as insensitivity to station removal at random. Community structure is also evident in the streamflow network. A network theoretic community detection algorithm identified separate communities, each of which appears to be defined by the combination of its median seasonal flow regime (pluvial, nival, hybrid, or glacial, which in this region in turn mainly reflects basin elevation) and geographic proximity to other communities (reflecting shared or different daily meteorological forcing). Furthermore, betweenness analyses suggest a handful of key stations which serve as bridges between communities and might be highly valued. We propose that an idealized sampling network should sample high-betweenness stations, small-membership communities which are by definition rare or undersampled relative to other communities, and index stations having large numbers of intracommunity links, while retaining some degree of redundancy to maintain network robustness.

scholarly journals Complex network and fractal theory for the assessment of water distribution network resilience to pipe failures

2017 ◽  
Vol 18 (3) ◽  
pp. 767-777 ◽  
Author(s):  
Armando Di Nardo ◽  
Michele Di Natale ◽  
Carlo Giudicianni ◽  
Roberto Greco ◽  
Giovanni Francesco Santonastaso
Keyword(s):  
Complex Network ◽  
Water Distribution ◽  
Fractal Theory ◽  
Distribution Networks ◽  
Pipe Failure ◽  
Operational Conditions ◽  
Complex Network Theory ◽  
Topological Features ◽  
Wide Range ◽  
The Impact

AbstractWater distribution networks (WDNs) must keep a proper level of service under a wide range of operational conditions, and, in particular, the analysis of their resilience to pipe failures is essential to improve their design and management. WDNs can be regarded as large sparse planar graphs showing fractal and complex network properties. In this paper, the relationship linking the geometrical and topological features of a WDN to its resilience to the failure of a pipe is investigated. Some innovative indices have been borrowed from fractal geometry and complex network theory to study WDNs. Considering all possible network configurations obtained by suppressing one link, the proposed indices are used to quantify the impact of pipe failure on the system's resilience. This approach aims to identify critical links, in terms of resilience, with the help of topological metrics only, and without recourse to hydraulic simulations, which require complex calibration processes and come with a computational burden. It is concluded that the proposed procedure, which has been successfully tested on two real WDNs located in southern Italy, can provide valuable information to water utilities about which pipes have a significant role in network performance, thus helping in their design, planning and management.

Complexity Analysis of Public Transportation Network in Zhangjiagang City Using Complex Network Theory

2012 ◽  
Vol 546-547 ◽  
pp. 1211-1216
Author(s):  
Yong Wang ◽  
Ta Zhou
Keyword(s):  
Complex Network ◽  
Public Transportation ◽  
Path Length ◽  
Complexity Analysis ◽  
Transportation Network ◽  
Average Path Length ◽  
Clustering Coefficient ◽  
Power Law Distribution ◽  
Complex Network Theory ◽  
Public Transportation Network

Public transportation network has been proven that it can be simulated as a complex network. In this paper, a bus transport system of Zhangjiagang city is considered. Network degree distribution, average path length, and clustering coefficient are utilized as criteria to analyze as the complexity of the network. Experimental results show that the network which is in line with power-law distribution has a smaller average path length and a large clustering coefficient. It also indicates that, the networks of Zhangjiagang public bus system are not a small-world network with scale-free property.

scholarly journals Identification of Key Flight Conflict Nodes Based on Complex Network Theory

2020 ◽  
Vol 38 (2) ◽  
pp. 279-287
Author(s):  
Minggong Wu ◽  
Zekun Wang ◽  
Xusheng Gan ◽  
Guozhou Yang ◽  
Xiangxi Wen
Keyword(s):  
Complex Network ◽  
Network Theory ◽  
Air Traffic ◽  
Clustering Coefficient ◽  
Entropy Weight ◽  
Complex Network Theory ◽  
Node Importance ◽  
Entropy Weight Method ◽  
Weight Method ◽  
Terminal Area

The air traffic density in the terminal area is high and the traffic situation is relatively complex by the development of aviation, which brings great challenges to controller. In order to understand the flight situation and provide decision basis for controllers, this paper proposes a key flight conflict nodes identification method based on complex network theory and Analytic Hierarchy Process (AHP)-entropy weight method. Firstly, an aircraft state network is established with aircraft as nodes and Airborne Collision Avoidance System (ACAS) communication relations as connecting edges. On this basis, four parameters, node degree, node weight, clustering coefficient and betweenness, are selected as evaluation indexes of node importance, and the weight of each index is determined by using AHP. And entropy weight method is introduced to revise the results. Node importance is calculated through multi-attribute decision-making method to determine key conflict aircrafts. The simulation and experiment on the artificial network and the aircraft state network of a certain day in the terminal area of Kunming Changshui Airport show that the method proposed in this paper can identify the key flight conflict nodes in the aircraft state network, allocate the selected node deployment can effectively reduce the complexity of the aircraft state network, can provide reference for air traffic control services (ATCS), and reduce the allocation difficulty of controller.

scholarly journals Research on Evolutionary Mechanism of Agile Supply Chain Network via Complex Network Theory

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Nai-Ru Xu ◽  
Jia-Bao Liu ◽  
De-Xun Li ◽  
Jun Wang
Keyword(s):  
Supply Chain ◽  
Complex Network ◽  
Network Theory ◽  
Clustering Coefficient ◽  
Supply Chain Network ◽  
Evolutionary Mechanism ◽  
Complex Network Theory ◽  
Scale Free ◽  
Agile Supply Chain ◽  
Network Research

The paper establishes the evolutionary mechanism model of agile supply chain network by means of complex network theory which can be used to describe the growth process of the agile supply chain network and analyze the complexity of the agile supply chain network. After introducing the process and the suitability of taking complex network theory into supply chain network research, the paper applies complex network theory into the agile supply chain network research, analyzes the complexity of agile supply chain network, presents the evolutionary mechanism of agile supply chain network based on complex network theory, and uses Matlab to simulate degree distribution, average path length, clustering coefficient, and node betweenness. Simulation results show that the evolution result displays the scale-free property. It lays the foundations of further research on agile supply chain network based on complex network theory.

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