Systemic risk and dynamics of contagion: a duplex inter-bank network

This paper constructs a duplex banking network formed by credit relationships and information interaction via the banks’ balance sheet to model the structure of systemic risk and investigate the dynamic mechanism of contagion in terms of default and liquidity infection along with the factors that affect the extent of the contagion. We systematically explain the role that duplex banking networks play in different aspects of risk contagion. Through theoretical analysis and simulations, we conclude that asymmetric information interaction would increase the inflexibility of the system, which leads to liquidity shortage and possibly the collapse of the whole market. The weakness of systemic risk in the interior of the complex banking system can be characterized by the partial discount factor using illiquid assets in the information network. By improving the connectedness of the information network of the duplex networks, the spread of contagion can be partially slowed.     

Short-run disequilibrium adjustment and long-run equilibrium in the international stock markets: A network-based approach

In this paper, we propose a network-based analytical framework that exploits cointegration and the error correction model to systematically investigate the directions and intensities in terms of the short-run disequilibrium adjustment towards long-run equilibrium affecting the international stock markets during the period of 5 January 2007 to 30 June 2017. Under this setting, we investigate whether and how the cross-border directional interconnectedness within the world’s 23 developed and 23 emerging stock markets altered during the entire period of 2007–2017, and two specific periods of 2007–2009 Global Financial Crisis and 2010–2012 European Sovereign Debt Crisis. The main results indicate that the magnitude of the short-run disequilibrium adjustment towards long-run equilibrium for individual stock markets is not homogeneous over different time scales. We report that the changes in directional interconnectedness within stock markets worldwide did occur under the impact of the recent financial crises. The derived networks of stock markets interconnectedness allow us to visually characterize how specific stock markets from different regions form interconnected groups when exhibiting similar behaviours, which none the less provides significant information for strategic portfolio and risk management.     

改进的ＢＡ无标度网络模型在企业集群中的应用

各组成元素间的网络关系是企业集群的本质特征,其总体竞争力与其内部网络具有紧密联系。运用复杂网络理论研究了企业集群的无标度网络特征,并运用改进的无标度网络模型来定量分析集群网络中各构成要素的重要性,为集群向既定目标发展提供了控制依据。     

开展数学实验提高《复变函数与积分变换》课程教学质量

阐述了为加强大学数学教育过程中的实践性教学环节,注重大学生对数学知识应用能力的培养,在《复变函数与积分变换》课程中开展数学实验教学的必要性;着重探讨了我们在《复变函数与积分变换》课程数学实验教学中正在进行的教学方法、教学内容和课程考核等方面的改革。     

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 effect of interconnectivity on stock returns during the Global Financial Crisis

This paper examines the role of interconnectivity in global stock markets during the Global Financial Crisis (GFC) using a comprehensive dataset of 8,827 firms traded in developed and emerging markets. Our contribution includes two key findings. We first use a difference-in-differences approach to show that stocks in countries with higher trade openness ex-ante to the GFC experienced lower average and annual cumulative returns of 9.08 p.p. and 36.32 p.p., respectively, compared to stocks traded in less exposed countries, one year after the crisis outbreak. Second, we employ complex network theory to analyze the role of network interconnectedness in our baseline results. To construct the network of interdependence between stock returns, we utilize a regularized Vector Autoregression Model, which enables us to overcome the limitations of commonly used correlation networks. Our findings suggest that while a firm’s high connectivity before the crisis can alleviate adverse shock effects resulting from export dependence, this effect may be weakened if the firm’s performance is closely linked to central firms.     

“双创”时代高校创客空间的复杂适应系统分析及优化策略

“大众创业、万众创新”时代,创客空间建设已成为高校扶持大学生创业的主流模式和重要举措。基于复杂适应系统（CAS）理论,阐释了高校创客空间的开放性、非线性、自组织性和涌现性等系统特征,指出高校创客空间的演进过程包括接触和交互两个阶段,在其演进过程中,标识机制和积木机制扮演着重要角色。最后,从CAS视角提出促进高校创客空间发展和系统优化的建议。     

重大突发公共卫生事件科技研发应急体系运行机制研究

在突发事件应急管理过程中,科技研发支撑作用十分关键,亟需建立突发公共卫生事件科研应急体系长效运行机制。基于科技研发应急体系的复杂性、适应性特征,从主体属性和体系架构两个层面入手,分析重大突发公共卫生事件科技研发应急体系的复杂适应系统特征,运用复杂适应系统理论模型和动态闭环螺旋模型,研究重大突发公共卫生事件科技研发应急体系运行机制。研究发现,重大突发公共卫生事件背景下,科技研发应急体系具有复杂适应系统的7个基本特征,是典型的复杂适应系统;科技研发应急体系中,科研攻关专家组、诊疗医院、科技部门等科研主体具有各自内部模型,并通过6大标识进行聚集;科技研发应急体系存在事件—需求引导、主体协同、资源交互、成果转化机制。同时,新冠病毒肺炎疫情应对实践表明,疫情防控救治进程中科技研发应急体系存在并遵循上述运行机制。     

产业集群知识转移复杂系统反馈结构分析

产业集群内知识转移过程构成一个复杂的社会经济系统,在其转移过程中存在制约和促进系统发展的反馈结构。只有准确分析其系统结构才能有效把握系统行为,为管理对策的制定提供依据。利用系统动力学反馈动态复杂性分析理论与技术,建立了有效刻画产业集群内知识转移过程复杂系统的结构模型。利用基模分析技术分析了系统中的反馈关系,进行管理对策的生成研究,实现了以系统科学方法有效分析产业集群内知识转移过程的目的。