陕西省交通基础设施对经济增长的空间溢出效应

为了从外部性角度说明目前陕西省交通基础设施的建设和投资在地域上存在的问题，为陕西省交通基础设施建设方向提供理论帮助，基于陕西省2009~2017年间各市相关数据，在交通基础设施对经济增长效应研究的直接效应和溢出效应基础上，加入空间要素，构建生产函数和空间权重矩阵，通过自相关检验（莫兰指数）、LM检验和 Hausman检验，选取合适的空间面板计量模型对陕西省交通基础设施的经济溢出情况进行研究。研究认为，2009~2017年间陕西省交通基础设施对经济增长的溢出效应（显著）整体为负，但依然存在正溢出的局部地区，即以西安为首的经济聚集区（西安、宝鸡、咸阳）和榆林、延安联合的陕北经济聚集区，资源过于集中和两个高地之间缺乏互联互通是整体呈现负溢出的重要原因。在地域分配的量和质上应充分考虑交通基础设施的溢出效应，避免资源过度集中在西安，在两个经济高地之间打通一条经济要道，并重点扶持相对落后又有发展前景的城市可促使陕西经济发展由总体集聚向总体扩散转变。     

Twitter,incivility, and presidential communication: A theoretical incursion into spectacle and power

ABSTRACT

By approaching civility as an operational logic for democracy, we ask how incivility is a strategy related to power and domination, particularly from the president of the United States. We propose that Twitter is part of an infrastructure of incivility, through which structures and discursive mechanisms contribute to a devaluation of normative democratic discourses. Spectacle provides a theoretical framework to contextualize the forces at play in mediating our relations. Using President Trump’s Twitter use as a case study, we offer four propositions that together formulate a framework for theorizing the strategic use and deployment of incivility as an increasingly legitimate, yet problematic tool for democratic governance.     

A Probabilistic Model of the Economic Risk to Britain's Railway Network from Bridge Scour During Floods

Scour (localized erosion by water) is an important risk to bridges, and hence many infrastructure networks, around the world. In Britain, scour has caused the failure of railway bridges crossing rivers in more than 50 flood events. These events have been investigated in detail, providing a data set with which we develop and test a model to quantify scour risk. The risk analysis is formulated in terms of a generic, transferrable infrastructure network risk model. For some bridge failures, the severity of the causative flood was recorded or can be reconstructed. These data are combined with the background failure rate, and records of bridges that have not failed, to construct fragility curves that quantify the failure probability conditional on the severity of a flood event. The fragility curves generated are to some extent sensitive to the way in which these data are incorporated into the statistical analysis. The new fragility analysis is tested using flood events simulated from a spatial joint probability model for extreme river flows for all river gauging sites in Britain. The combined models appear robust in comparison with historical observations of the expected number of bridge failures in a flood event. The analysis is used to estimate the probability of single or multiple bridge failures in Britain's rail network. Combined with a model for passenger journey disruption in the event of bridge failure, we calculate a system‐wide estimate for the risk of scour failures in terms of passenger journey disruptions and associated economic costs.     

“一带一路”沿线国家互联网基础设施的贸易效应——基于贸易成本和全要素生产率的中介效应分析

在"一带一路"建设背景下，研究阐释"一带一路"沿线国家互联网基础设施的贸易效应及其作用机制，对于当前中国优化沿线国家的互联网基础设施建设布局，有效激发贸易效应，应对外贸环境的不利冲击，具有重要的现实意义。文章基于贸易成本和全要素生产率的分析视角，构建2007-2017年中国与45个"一带一路"沿线国家的面板数据，运用中介效应模型实证考察"一带一路"沿线国家互联网基础设施的贸易效应。总体检验结果表明，"一带一路"沿线国家互联网基础设施有利于中国与沿线国家的双边贸易往来，且主要通过降低贸易成本而非提高全要素生产率来发挥贸易效应。异质性检验结果表明，无论区分贸易方向还是沿线国家经济发展差异，互联网基础设施都具有明显的贸易效应，其中：贸易成本的中介效应主要发生在沿线发达国家对中国进、出口贸易中；全要素生产率的中介效应主要发生在沿线国家对中国出口贸易以及沿线发展中国家对中国进出口贸易中。新形势下中国参与"一带一路"沿线国家的互联网基础设施建设，要注意合理布局和把握建设力度，既培育贸易增长新动能，也优化进出口贸易结构。     

Optimization of Cascade‐Resilient Electrical Infrastructures and its Validation by Power Flow Modeling

Large‐scale outages on real‐world critical infrastructures, although infrequent, are increasingly disastrous to our society. In this article, we are primarily concerned with power transmission networks and we consider the problem of allocation of generation to distributors by rewiring links under the objectives of maximizing network resilience to cascading failure and minimizing investment costs. The combinatorial multiobjective optimization is carried out by a nondominated sorting binary differential evolution (NSBDE) algorithm. For each generators–distributors connection pattern considered in the NSBDE search, a computationally cheap, topological model of failure cascading in a complex network (named the Motter‐Lai [ML] model) is used to simulate and quantify network resilience to cascading failures initiated by targeted attacks. The results on the 400 kV French power transmission network case study show that the proposed method allows us to identify optimal patterns of generators–distributors connection that improve cascading resilience at an acceptable cost. To verify the realistic character of the results obtained by the NSBDE with the embedded ML topological model, a more realistic but also more computationally expensive model of cascading failures is adopted, based on optimal power flow (namely, the ORNL‐Pserc‐Alaska) model). The consistent results between the two models provide impetus for the use of topological, complex network theory models for analysis and optimization of large infrastructures against cascading failure with the advantages of simplicity, scalability, and low computational cost.     

A Decision Framework for Managing Risk to Airports from Terrorist Attack

This article presents an asset‐level security risk management framework to assist stakeholders of critical assets with allocating limited budgets for enhancing their safety and security against terrorist attack. The proposed framework models the security system of an asset, considers various threat scenarios, and models the sequential decision framework of attackers during the attack. Its novel contributions are the introduction of the notion of partial neutralization of attackers by defenders, estimation of total loss from successful, partially successful, and unsuccessful actions of attackers at various stages of an attack, and inclusion of the effects of these losses on the choices made by terrorists at various stages of the attack. The application of the proposed method is demonstrated in an example dealing with security risk management of a U.S. commercial airport, in which a set of plausible threat scenarios and risk mitigation options are considered. It is found that a combination of providing blast‐resistant cargo containers and a video surveillance system on the airport perimeter fence is the best option based on minimum expected life‐cycle cost considering a 10‐year service period.     

Beyond ‘bikelash’: engaging with community opposition to cycle lanes

This article explores the phenomenon of ‘bikelash’, or organised community opposition to cycle lanes. Urban residents commonly cite bicycle lanes, a space on the road reserved for cyclists, as the infrastructure most likely to encourage them to cycle. Yet the introduction of cycle lanes is often controversial. This article explores the phenomenon of bikelash, asking: Why does it occur? And what are the best ways to respond to it? A critical review of the literature on ‘contested’ cycle lane projects is undertaken in order to explore how this phenomenon can best be conceptualised within a mobilities framework.     

基于元网络分析的重大基础设施建设项目风险评估框架与实证

重大基础设施项目具有战略性、集成性、复杂性等特征，项目容易受到多种风险因素的综合影响，导致项目目标的偏离。现有风险评估与风险决策的方法缺乏对于风险因素、风险事件之间关联的分析。为了实现重大基础设施建设项目综合系统的风险评估，本文采用元网络分析方法，构建项目目标、风险事件和风险因素的交互模型，揭示重大基础设施风险事件发生机制的黑箱过程。风险评估过程中，通过多个网络叠加运算分析每个风险因素对于各种风险事件以及项目各目标的影响情况，改进了以往仅对风险因素单一影响程度的风险评估方法。同时，本研究选择我国某河流水电站过坝运输项目方案比选的风险评估过程验证方法的适用性。     

Topological Performance Measures as Surrogates for Physical Flow Models for Risk and Vulnerability Analysis for Electric Power Systems

Critical infrastructure systems must be both robust and resilient in order to ensure the functioning of society. To improve the performance of such systems, we often use risk and vulnerability analysis to find and address system weaknesses. A critical component of such analyses is the ability to accurately determine the negative consequences of various types of failures in the system. Numerous mathematical and simulation models exist that can be used to this end. However, there are relatively few studies comparing the implications of using different modeling approaches in the context of comprehensive risk analysis of critical infrastructures. In this article, we suggest a classification of these models, which span from simple topologically‐oriented models to advanced physical‐flow‐based models. Here, we focus on electric power systems and present a study aimed at understanding the tradeoffs between simplicity and fidelity in models used in the context of risk analysis. Specifically, the purpose of this article is to compare performance estimates achieved with a spectrum of approaches typically used for risk and vulnerability analysis of electric power systems and evaluate if more simplified topological measures can be combined using statistical methods to be used as a surrogate for physical flow models. The results of our work provide guidance as to appropriate models or combinations of models to use when analyzing large‐scale critical infrastructure systems, where simulation times quickly become insurmountable when using more advanced models, severely limiting the extent of analyses that can be performed.     

Impact of socio-economic infrastructure investments on income inequality in Iran

One of the main subjects, governments have been facing is fair distribution of income, and making effort to improve it. In this study, we evaluated the effects of economic (energy, water, ICT) and social (health, education) infrastructure expenses on income inequality in the Iranian provinces for the period of 2007–2016 by the panel corrected standard errors (PCSE) model. The results show that social and economic infrastructures improvements reduce income inequality. However, the magnitude of these effects varies. Investment on education, healthcare, communication technology, energy, and water infrastructures has the greatest impact on income inequality reduction, respectively. Therefore, in order to reduce inequality in deprived areas, combination and optimal allocation of economic and social infrastructures should be considered.