Co‐movements in commodity prices: a note based on network analysis

This article analyses co‐movements in a wide group of commodity prices during the time period 1992–2010. Our methodological approach is based on the correlation matrix and the networks inside. Through this approach we are able to summarize global interaction and interdependence, capturing the existing heterogeneity in the degrees of synchronization between commodity prices. Our results produce two main findings: (a) we do not observe a persistent increase in the degree of co‐movement of the commodity prices in our time sample, however from mid‐2008 to the end of 2009 co‐movements almost doubled when compared with the average correlation; (b) we observe three groups of commodities which have exhibited similar price dynamics (metals, oil and grains, and oilseeds) and which have increased their degree of co‐movement during the sampled period.     

基于复杂网络理论的电动汽车充电设施布局合理性研究

提出了一种基于复杂网络理论构建电动汽车充电设施网络的模型,分别构建了上海、西安、合肥和大连的电动汽车充电设施网络,并分析了其电动汽车充电设施的运营情况以及布局的合理性。通过构建理想情况下的电动汽车充电设施网络,研究电动汽车充电设施网络的发展趋势。仿真结果显示:电动汽车充电设施网络的结构对电动汽车充电设施的利用率和稳定性有显著影响——该研究结果在实际网络中得到了验证。     

Synchronization and diversity in business cycles: a network analysis of the European Union

In this article, we use a correlation matrix and its internal networks to analyse business cycle synchronization across Europe since 2000. This methodology allows us to summarize individual country interactions and co-movements while also capturing the existing heterogeneity of connectivity within the European economic system. Our results indicate that synchronization of the euro zone countries remained stable from 1999 until the current financial crisis, after which co-movements increased sharply and synchronization rose to the highest in the time sample. By endogenously identifying clusters of countries with close connections in their business cycle, we also refute the commonly accepted notion of identifiable core and peripheral euro zone countries.     

On the multi-dimensionality and sampling of air transport networks

Complex network theory is a framework increasingly used in the study of air transport networks, thanks to its ability to describe the structures created by networks of flights, and their influence in dynamical processes such as delay propagation. While many works consider only a fraction of the network, created by major airports or airlines, for example, it is not clear if and how such sampling process bias the observed structures and processes. In this contribution, we tackle this problem by studying how some observed topological metrics depend on the way the network is reconstructed, i.e. on the rules used to sample nodes and connections. Both structural and simple dynamical properties are considered, for eight major air networks and different source datasets. Results indicate that using a subset of airports strongly distorts our perception of the network, even when just small ones are discarded; at the same time, considering a subset of airlines yields a better and more stable representation. This allows us to provide some general guidelines on the way airports and connections should be sampled.     

The Urban Unbound: London's Politics and the 2012 Olympic Games

Global events such as London's 2012 Olympic Games raise questions about the ways in which embedded political arrangements take their shape from relationships that stretch across and beyond urban boundaries. In this article, the urban politics that we wish to capture is not one that is merely located in the city, but rather one that has to constantly take into account the mediated demands folded (as it were) into the urban arena. In the first part of the article, the corporate politics of an Olympic‐related urban regeneration are outlined and then considered, first as a staged setting for interaction, a kind of placeless political engagement, and then as a more embedded spatial politics that takes into account the leverage of networked groups acting within and beyond the city. Following that, we explore the politics of regeneration when campaign groups and alternative coalitions of interest raise their own political demands by drawing on references outside of their immediate urban area and attempt to steer political dialogue in ways that extend the reach of urban politics. The urban politics at stake in this context, we argue, appears to work more through topology than a series of mapped connections; through actors registering their presence in ways that often dissolve the tension between inside and outside rather than define it in terms of separate political spaces.     

Exploring promising vacant technology areas in a technology-oriented company based on bibliometric analysis and visualisation*

Under technology convergence phenomenon and fast-changing social demands, it is inevitable to collect and analyze a large amount of information in order to determine a vacant technology area that can preempt the market. Thus, this research aims to propose a systematic approach to identifying vacant technology areas by reflecting the technological competitiveness of company. Vacant technology is identified as underdeveloped and undeveloped vacant areas for a firm in both macroscopic and microscopic view by generating a technology level map in a practical view. In addition, vacant technology can be identified as undiscovered vacant areas in a microscopic view by using generative topology mapping (GTM) and local outlier factor (LOF). In a respective view, the promising vacant areas are defined by developing various indicators that represent competitive strength, growth stage, and marketability in both macro and micro level, and novelty indicators that represent originality and marketability in the micro level. The proposed approach is applied to the information & communication technology (ICT) R&D technology classification to validate its usefulness. The results can be used to enhance the practical application of R&D technology planning, understand the current technology level, and perform future technology planning.     

QuickDesktop组建一卡通公共机房网络故障分析

基于校园一卡通消费的公共机房应确保数据安全,使用QuickDesktop系统可有效解决问题,但网络拓扑将影响实施效果,本文分析了组网过程中网络拓扑故障的原因,提出了解决办法。     

局部线性嵌入算法在图像处理中的应用

为了避免光照、姿态、附属物等因素对同一个图像矩阵的差异和识别的影响,采用了局部线性嵌入(LLE)算法,首先对图像库里的图像进行光照预处理,再进用LLE运算得到低维图像特征,并通过仿真实验获得了既能使图像识别避免光照等因素的影响,又能使图像识别率有了大幅度的提高,从而得到利用局部线性嵌入算法对图像进行处理的结论。     

综合化信号与信息处理平台设计与实现

为解决大规模分布式异构实时处理平台在航空电子模块化综合条件下的体系结构问题,在分析联合标准化航电系统架构特点的基础上,提出一种基于串行RapidIO硬总线和虚通道软总线互连的开放式系统架构,并完成一套基于该架构的综合化信号与信息处理机,实现了真正意义上的芯片级互连、低延时、多节点、可扩展、可重构的航空电子综合化应用平台。