Research On The Balance Of Urban Public Transport Networks Based On The Synchronization Of Complex Networks

In recent years, with the rapid progress of urbanization and much attention on transportation systems, there has been a boom in. The facilities of urban public transportation in China get more and more capable. Public transportation itself, however, can not put an end to the problem of traffic congestion, especially for some big cities. Thus new studies in which urban public transportation systems were firstly viewed as complex networks and then the theory of complex network was applied to analyze various properties of the transportation network, have won great concerns.A lot of scholars carry on studies to public transportation network, but most of the papers simply involve either the static state or the stability analysis of public transportation network and they can be classified into two kinds: the first one is about topological properties of transportation network while the second is about the reliability or robustness of the network as well as the structural optimization. New perspectives are still in need because traditional methods are proved to be ineffective to solve the complexly-computed and large-scale problem. Not only structural properties of network topology itself but also dynamical properties of the urban public transportation network are worthy to be analyzed. This will guide us to find reasons which account for traffic jams and factors which have an impact on the normal operating of public transportation, and thus provide theoretic supports to effectively improve the city’s traffic.This dissertation proposes a new model of complex multi-links public transportation network and a second model of complex multi-weight public transportation network by applying the synchronization theory into urban public transportation network. Some static indexes are re-defined and their implications in the transportation network are discussed. The adaptive synchronization rules of the two networks are also introduced and the impact of some common indexes such as passengers’ flow and departure frequency on the balance of network are analyzed. Due to its theoretical contribution, it is believed that the work will be helpful for public agency to make decisions, thus relieve the prevalent problem of traffic jams. In conclusion, the dissertation is structured as follows:(1) Based on the systematic analysis and summaries for the research of related literature at home and abroad, this paper lists some limitations as well as contributions of prior researches. At the same time, we point out the existing problems and show the research direction and the main content in this paper.(2) Followed by the basics of complex networks, global synchronization methods for the complex network with time delay and time-varying delays are discussed. The adaptive synchronization rules are also given.(3) A new model of complex multi-links public transportation network is proposed. Not only some static indexes are re-defined, but also new indexes such as Direction Degree, Neighbor Strength, are defined. Their implications in public transportation networks are also explained.(4) The complex multi-links public transportation network is split into multiple sub-networks with single link, then global synchronization rules for the complex multi-link public transportation network with time delay and time-varying delays are given. The balance of the complex multi-links public transportation network is further analyzed by discussing the impact of parameters such as passenger flow density and departure frequency, on global synchronization. A dissipation model of queue length is also built to simulate the impact of departure frequency on stranded passengers.(5) Given the fact that edges of a complex network may have different weights, a second model of complex multi-weights public transportation network is proposed. Some static indexes, such as the node weight, the similarity of node weight and edge weights are re-defined. The complex multi-weights public transportation network is split into multiple sub-networks with single weight, then global synchronization rules for the complex multi-weight public transportation network with time delay and time-varying delays are given. Their balances are further analyzed by discussing the impact of parameters on global synchronization.(6) Taking a public transportation hub as an example and the bus lines passing through it as the network nodes, this dissertation establishes a complex multi-weights public transportation hub network. The balance of the network is further discussed by considering a case with one broken bus line and another case with one more bus line. Also, the impact of departure frequency on the network balance is analyzed by considering a case in rush hours and another case with sharp increases of passengers for one of the bus lines.