Liang Gao

Liang Gao
Beijing Jiaotong University | NJTU · School of Traffic and Transportation

Ph.D

About

44
Publications
7,693
Reads
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511
Citations
Introduction
Current research interests: Complex networks and the dynamics on networks Urban Traffic based on network science and big data

Publications

Publications (44)
Article
Full-text available
Robustness studies on integrated urban public transport networks have attracted growing attention in recent years due to the significant influence on the overall performance of urban transport system. In this paper, topological properties and robustness of a bus–subway coupled network in Beijing, composed of both bus and subway networks as well as...
Article
Full-text available
In this paper, we propose weighted h-index h w and h-index strength s h to measure spreading capability and identify the most influential spreaders. Experimental results on twelve real networks reveal that s h was more accurate and more monotonic than h w and four previous measures in ranking the spreading influence of a node evaluated by the singl...
Article
Full-text available
Coreness is one of the important indicators to measure the importance of a node. Traditionally, the coreness of a node is measured by k-core decomposition. However, to measure the coreness in a dynamic network, the k-core decomposition method becomes very time-consuming and inefficient, and cannot meet the need in very large real networks. Recently...
Article
Full-text available
To improve efficiency and reduce the total scheduling cost of the public bicycle system (PBS), dynamic scheduling based on the predicted inventory variation rate (DS-PIVR) is proposed. Regarding a station in the PBS as an inventory system, its inventory variation rate during the scheduling period and its inventory rate at the end of the scheduling...
Article
Identifying influential spreaders plays a crucial role in understanding and controlling the spreading processes on complex networks. Previous works mainly focus on the direct spread via edge e ij from node i to node j. However, the indirect spread through an intermediate node k, i.e. the infection is spread successively via edge e ik and edge e kj...
Article
Full-text available
Percolation transition is widely observed in networks ranging from biology to engineering. While much attention has been paid to network topologies, studies rarely focus on critical percolation phenomena driven by network dynamics. Using extensive real data, we study the critical percolation properties in city traffic dynamics. Our results suggest...
Preprint
An articulation point (AP) is any node whose removal increases the number of connected components of a graph. There is no doubt that this kind of node which occupies a non-ignorable fraction of real-world networks plays a key role in ensuring the connectivity. However, we should not thus neglect the impacts of non-APs nodes. In this paper, we defin...
Preprint
Ranking node importance is crucial in understanding network structure and function on complex networks. Degree, h-index and coreness are widely used, but which one is more proper to a network associated with a dynamical process, e.g. SIR spreading process, is still unclear. To fill this gap, a, which is extracted from the fitting function (f(x)=1-1...
Article
Full-text available
Although recent studies have found that the long-term correlations relating to the fat-tailed distribution of inter-event times exist in human activity and that these correlations indicate the presence of fractality, the property of fractality and its origin have not been analyzed. We use both detrended fluctuation analysis and multifractal detrend...
Article
Full-text available
Spreading is a ubiquitous process in the social, biological and technological systems. Therefore, identifying influential spreaders, which is important to prevent epidemic spreading and to establish effective vaccination strategies, is full of theoretical and practical significance. In this paper, a weighted h-index centrality based on virtual node...
Article
Full-text available
Percolation transition is widely observed in networks ranging from biology to engineering. While much attention has been paid on network topologies, studies rarely focus on critical percolation phenomena driven by network dynamics. Using extensive real data, we study the critical percolation properties of the dynamics of city traffic. We find that...
Conference Paper
Analyzing traffic incidents is an important part of traffic incident management (TIM). In this paper, a traffic incident analysis method based on the accumulative ratio (AR) and extended spectral envelope (ESE) methods is presented. AR is used to analyze the spatial-temporal evolution of a bottleneck caused by a traffic incident. The ESE method is...
Conference Paper
This paper aims to assess road traffic noise in the Xizhimen Overpass area, Beijing. Equivalent continuous sound pressure level (Leq), traffic noise index (TNI), noise pollution level (LNP), maximum sound level (Lmax), and noise excess limits (NEL) are employed to quantitatively measure the level of road traffic noise. Results shown that in both wo...
Article
Moderate length of time window can get the best accurate result in detecting the key incident time using extended spectral envelope. This paper presents a method to calculate the moderate length of time window. Two factors are mainly considered: (1) The significant vertical lines consist of negative elements of eigenvectors; (2) the least amount of...
Article
A traffic incident analysis method based on extended spectral envelope (ESE) method is presented to detect the key incident time. Sensitivity analysis of parameters (the length of time window, the length of sliding window and the study period) are discussed on four real traffic incidents in Beijing. The results show that: (1) Moderate length of tim...
Article
Full-text available
Previous works have shown the universality of allometric scalings under density and total value at city level, but our understanding about the size effects of regions on them is still poor. Here, we revisit the scaling relations between gross domestic production (GDP) and population (POP) under total and density value. We first reveal that the superl...
Article
Full-text available
Recent discoveries of human activity reveal the existence of long-term correlation and its relation with the fat-tailed distribution of inter-event times, which imply that there exists the fractality of human activity. However, works further analyzing the type of fractality and its origin still lack. Herein, DFA and MFDFA methods are applied in the...
Article
Habitat fragmentation is a harmful impact on wild animals. In this paper, we propose an agent-based simulation model to estimate the fragmentation impacts (FIs) on wild animals caused by road network. We employ predator-prey system as a simplified ecological system, and investigate FIs on wildlife by adding roads gradually into the habitat of wildl...
Article
Full-text available
Social media, regarded as two-layer networks consisting of users and items, turn out to be the most important channels for access to massive information in the era of Web 2.0. The dynamics of human activity and item popularity is a crucial issue in social media networks. In this paper, by analyzing the growth of user activity and item popularity in...
Article
Full-text available
Recent advances on human dynamics have focused on the normal patterns of human activities, with the quantitative understanding of human behavior under extreme events remaining a crucial missing chapter. This has a wide array of potential applications, ranging from emergency response and detection to traffic control and management. Previous studies...
Article
In intelligent transport system, some advanced information feedback strategies have been developed to reduce the oscillations and enhance the capacity on the road level. However, seldom strategies have considered the information delay and user equilibrium (UE) objective. Here, a derivative cost feedback strategy (DCFS) is proposed to reduce the inf...
Article
Abstract—With the gradually development of Beijing Subway network, passenger volume grows fast and the government bear more and more subsidies. We focus on the price elasticity of travel demand of Beijing Subway, in order to point out the relationship between them. We hope our study can provide the government important reference in designing more e...
Article
Full-text available
To investigate the relationship between cyclist violation and waiting duration, the red-light running behavior of nonmotorized vehicles is examined at signalized intersections. Violation waiting duration is collected by video cameras and it is assigned as censored and uncensored data to distinguish between normal crossing and red-light running. A p...
Article
Full-text available
Many equilibrium models and algorithms based on homogeneous motorized traffic have been devised to model urban transport systems in developed countries, but they are inadequate when it comes to represent mixed-traffic urban transport systems, including automobiles, transit, bicycles, and pedestrians, in developing countries such as China or India....
Article
Full-text available
To investigate bicyclists' behavior at unsignalized intersections with mixed traffic flow, a bicycle capacity model of borrowed-priority merge was developed by the addition-conflict-flow procedure. Based on the actual traffic situation, the concept of borrowed priority, in which the major-road bicycles borrow the priority of major-road cars to ente...
Article
Many algorithms have been presented to solve the traffic assignment problem. Recently, Bar-Gera introduced the concept of ``last common node'' into an origin-based algorithm to solve the traffic assignment problem. However, how to find the last common nodes has not been investigated in detail. In this paper, we present a matrix method for finding t...
Article
Real time system for vehicle travel time and traffic flow is an essential part of Intelligent Transportation Systems. In many Chinese cities, the interactions among buses, bicycles and cars bring difficulty to travel time prediction and traffic safety management. The aim of this paper is to develop a new model to estimate car travel time near bus s...
Article
Full-text available
Real time system for vehicle travel time and traffic flow is an essential part of Intelligent Transportation Systems. In many Chinese cities, the interactions among buses, bicycles and cars bring difficulty to travel time prediction and traffic safety management. The aim of this paper is to develop a new model to estimate car travel time near bus s...
Article
Full-text available
To determinate car capacity at bus stops with mixed traffic, a new theoretical approach was developed on the basis of additive-conflict-flows procedure. The procedure was extended from homogeneous traffic flow to mixed traffic flow. The conflicts among cars, buses and bicycles near the stop can be described by the extended procedure. The procedure...
Article
Full-text available
The structural characteristic of urban multimodal transport system was fully analyzed and then based on graph theory, a hierarchical network was proposed to describe the system. Simultaneously, the complex travelers' choice behaviors including traffic mode choice and route choice were analyzed in hierarchical network and based on the analysis of tr...
Article
Full-text available
Global degree/strength based preferential attachment is widely used as an evolution mechanism of networks. But it is hard to believe that any individual can get global information and shape the network architecture based on it. In this paper, it is found that the global preferential attachment emerges from the local interaction models, including di...
Article
Full-text available
Minimum box-covering method is a basic tool to measure fractal dimension of a network but unfortunately belongs to a family of NP-hard problems. Finding more accurate approximation in a relative shorter time is an important problem and attracts considerable attention. In this paper, the accuracy of the ball-covering approach for fractal dimension i...
Article
Phenomenon of asymmetry between odd and even node weight distribution in some complex networks, such as public transportation networks and Internet, is presented. Reasons related to this phenomenon are summarized, i.e., (1) edges are solid connections between nodes which are embedded in real geometric background, and (2) preferential mechanism duri...
Article
Full-text available
Food webs provide a prototype for studying the effects of attacks on complex networks. Instead of the variation of the relative size and average path length of the largest cluster, the loss of species is used to describe the effects of attacks for food webs. Taking the global energy transportation character of food webs into consideration, the node...
Article
The response of 14 food webs to attacks on vertices and edges is studied in this article. Taking account of the energy transportation character of food webs, attacks on vertices and edges based on betweenness are introduced into the experiment. Food web robustness, the fraction of species that had to be removed in order to result in a total loss of...
Article
Full-text available
In order to take the weight of connection into consideration and to find a natural measurement of weight, we have collected papers in Econophysics and constructed a network of scientific communication to integrate idea transportation among econophysicists by collaboration, citation and personal discussion. Some basic statistics such as weight per d...
Article
Full-text available
In order to take the weight of connection into consideration and to find a natural measurement of weight, we have collected papers in Econophysics and constructed a network of scientific communication to integrate idea transportation among econophysicists by collaboration, citation and personal discussion. Some basic statistics such as weight per d...
Article
Full-text available
The development of Econophysics is studied from the perspective of scientific communication networks. Papers in Econophysics published from 1992 to 2003 are collected. Then a weighted and directed network of scientific communication, including collaboration, citation and personal discussion, is constructed. Its static geometrical properties, includ...
Article
Speciation is the dominant mode for the origin of new species, which is one of the core problems of evolutionary biology. Recently, several empirical studies put forward disrup-tive sexual selection as an important driving force of sympatric speciation. Theoretical sexual-selection models are based on competition for mates, creating differential fi...

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