Resilience assessment and optimization method of city road network in the post-earthquake emergency period

The post-earthquake emergency period,which is a sensitive time segment just after an event,mainly focuses on saving life and restoring social order.To improve the seismic resilience of city road networks,a resilience evaluation method used in the post-earthquake emergency period is proposed.The road seismic damage index of a city road network can consider the influence of roads,bridges and buildings along the roads,etc.on road capacity after an earthquake.A function index for a city road network is developed,which reflects the connectivity,redundancy,traffic demand and traffic function of the network.An optimization model for improving the road repair order in the post-earthquake emergency period is also developed according to the resilience evaluation,to enable decision support for city emergency management and achieve the best seismic resilience of the city road network.The optimization model is applied to a city road network and the results illustrate the feasibility of the resilience evaluation and optimization method for a city road network in the post-earthquake emergency period.

A novel method for approximating intercity networks： An empirical comparison for validating the city networks in two Chinese city-regions

A network perspective has increasingly become an organizational paradigm for understanding regional spatial structures. Based on a critical overview of existing empirical models for estimating intercity networks based on firm linkages, this study extends the re- cently proposed regional corporate city model algorithm by proposing a new method for ap- proximating urban networks based on the Iocational strategies of firms. The new method considers both regional and hierarchical network features and avoids the information loss associated with the conversion from two-mode firm-city networks to one-mode city-city networks. In addition, networks estimated by using the method proposed herein are suitable when employing social network analysis. Finally, this method is empirically validated by ex- amining intercity firm networks formed by advanced producer services firms in China＇s two largest metropolitan areas, namely the Yangtze River Delta and Pearl River Delta. The pre- sented empirical analysis suggests two main findings. First, in contrast to conventional methods （e.g., the interlocking city network model）, our new method produces regional and hierarchical urban networks that more closely resemble reality. Second, the new method al- lows us to use social network analysis to assess betweenness and closeness centralities. However, regardless of the model applied, the validity of any method that measures urban networks depends on the soundness of its underlying assumptions about how network actors （firms, in our case） interact.

Research on China City Network Based on Producer Service Industries

Based on the concept of the world city network(WCN), this paper analyzes city network that is based on producer service industries in China's Mainland at three levels. The corresponding findings include: firstly, at the sub-node level, the location decision-making of producer service industries is no longer merely dependent on linear expansion along the hinterland to establish spatial monopoly, but on a network layout mode based on setting up branch offices in core cities to maximize the profits; secondly, at the city node level, Beijing and Shanghai have become the two major cities for the agglomeration of producer service industries. The coastal city clusters are the principal areas for the concentration of producer service industries, while the majority of other cities are in the peripheral area of the network where there are comparatively low connectivities; thirdly, at the city network level, the primacy effect of Beijing and Shanghai in the city network is extremely signifi cant and the linkage among core cities, namely, Beijing, Shanghai, Guangzhou, and Shenzhen, in the three major city clusters forms the core network of the producer service industries in China's Mainland.

Measuring Network Configuration of the Yangtze River Middle Reaches Urban Agglomeration:Based on Modified Radiation Model

The objective of this study is to develop a framework for re-examining and re-defining the classical concepts of spatial interaction and reorganization in the urban system.We introduce a modified radiation model for spatial interactions,coupled with migration big data,transport accessibility algorithm,and city competitiveness assessment for efficient distribution of the inter-city flow through the network.The Yangtze River Middle Reaches(YRMR)urban agglomeration(UA)is chosen as the case study region to systematically identify and measure its spatial configuration and to gain insights for other UAs‘sustainable development in China.The results are also compared with those computed by the classical gravity model to systematically discuss the applicability of spatial interaction laws and models,and related practical policies for regional sustainable development are discussed based on the findings as well.The conclusions are highlighted below:1)Combining with the?city network paradigm‘and?central place theory‘can better express the spatial configurations of city systems in the context of?space of flows‘;2)The results validate the potentialities of a multi-analysis framework to assess the spatial configurations of city network based on the improved radiation model and network analysis tools;3)The applications of spatial interaction models should be considered according to the specific geographical entity and its spatial scale.

The Creative Cities Network

The Creative Cities Network, started by UNESCO in 2004, is one of the world’s highest-level non-governmental organizations in creative industry. The network focuses on the excellence of its member cities as its main product, and finds ways to maintain relevance in city life, local

中国城市间科学合作网络空间的层级性、集聚性与差异性分析（英文）

The Chinese urban system is currently experiencing a fundamental shift, as it moves from a size-based hierarchy to a network-based system. Contemporary studies of city networks have tended to focus on economic interactions without paying sufficient attention to the issue of knowledge flow. Using data on co-authored papers obtained from China Academic Journal Network Publishing Database （CAJNPD） during 2014-2016, this study explores several features of the scientific collaboration network between Chinese mainland cities. The study concludes that： （1） the spatial organization of scientific cooperation amongst Chinese cities is shifting from a jurisdiction-based hierarchical system to a networked system; and （2） several highly intra-connected city regions were found to exist in the network of knowledge, and such regions had more average internal linkages （14.21） than external linkages （8.69）, and higher average internal linkage degrees （14.43） than external linkage degrees （10.43）; and （3） differences existed in terms of inter-region connectivity between the Western, Eastern, and Central China regional networks （the average INCD of the three regional networks were 109.65, 95.81, and 71.88）. We suggest that China should engage in the development of regional and subregional scientific centers to achieve the goal of building an innovative country. Whilst findings reveal a high degree of concentration in those networks - a characteristic which reflects the hierarchical nature of China＇s urban economic structure - the actual spatial distribution of city networks of knowledge flow was found to be different from that of city networks based on economic outputs or population.

基于国际体育赛事的城市间联系及城市网络研究——以北京、伦敦、里约热内卢奥运会为例

With so many sports becoming increasingly popular,sports have come to play an important role in promoting the process of globalization and formatting the world city network(WCN).Previous studies have constructed the WCN based on the distribution of international sport federations(ISFs)and the sites of international sport events(ISEs),but there is still a lack of systematic research on the intercity connections caused by ISEs.Taking three most recent Olympic Games as cases,this paper explores intercity connections and WCN based on ISEs.The results show that(1)the Olympic WCN has city nodes around the world except in Antarctica,and the number and activity values of the cities in host countries may increase intensively during the Olympic Games.(2)A hierarchical city system with four tiers(global central cities,specialized central cities,national central cities and specialized cities)is formed by the intercity connections caused by the Olympic Games.(3)The WCN based on the Olympic Games,is made up of many subnetworks,while many differences occur due to the diverse decisions made by the Organizing Committee for the Olympic Games(OCOG),host cities or even host countries in the events associated with sponsorship activity and publicity activity.This study not only broadens the relevant fields of sports culture-oriented WCN research but also explores the instability of the WCN,which makes it an effective reference for WCN research based on ISEs.

基于公路客流的中国城市网络结构与空间组织模式（英文）

The use of multi-perspective and multi-scalar city networks has gradually developed into a range of critical approaches to understand spatial interactions and linkages. In particular, road linkages represent key characteristics of spatial dependence and distance decay, and are of great significance in depicting spatial relationships at the regional scale. Therefore, based on highway passenger flow data between prefecture-level administrative units, this paper attempted to identify the functional structures and regional impacts of city networks in China, and to further explore the spatial organization patterns of the existing functional regions, aiming to deepen our understanding of city network structures and to provide new cognitive perspectives for ongoing research. The research results lead to four key conclusions. First, city networks that are based on highway flows exhibit strong spatial dependence and hierarchical characteristics, to a large extent spatially coupled with the distributions of major megaregions in China. These phenomena are a reflection of spatial relationships at regional scales as well as core-periphery structure. Second, 19 communities that belong to an important type of spatial configuration are identified through community detection algorithm, and we suggest they are correspondingly urban economic regions within urban China. Their spatial metaphors include the administrative region economy, spatial spillover effects of megaregions, and core-periphery structure. Third, each community possesses a specific city network system and exhibits strong spatial dependence and various spatial organization patterns. Regional patterns have emerged as the result of multi-level, dynamic, and networked characteristics. Fourth, adopting a morphology-based perspective, the regional city network systems can be basically divided into monocentric, dual-nuclei, polycentric, and low-level equilibration spatial structures, while most are developing monocentrically.