军民融合社会关系网络对军民融合新创企业成长的影响

军民融合新创企业是推动我国国防建设和社会经济融合发展的重要力量，军民融合社会关系网络具有丰富的异质性资源，可以有效促进军民融合新创企业成长。借鉴社会网络理论，构建以关系深度、关系广度、关系高度为代表的军民融合社会关系网络、耦合共生与军民融合新创企业成长理论模型，通过对收集的304份军民融合新创企业问卷数据进行实证分析，结果发现：军民融合社会关系网络对军民融合新创企业成长具有正向影响；耦合共生在军民融合社会关系网络与军民融合新创企业成长间发挥中介作用；创业导向显著调节耦合共生与军民融合新创企业成长的关系。     

Investigating tail-risk dependence in the cryptocurrency markets: A LASSO quantile regression approach

We construct the complete network of tail risk spillovers among major cryptocurrencies using the Least Absolute Shrinkage and Selection Operator (LASSO) quantile regression. We capture important features of the network, including major risk-driving and major risk-receiving currencies, and the evolution of the tail dependence among the currencies over time. Importantly, we reveal a striking finding that the right tail dependence among the cryptocurrencies is significantly stronger than the left tail counterpart. This unique characteristic may have contributed to the rise in popularity of cryptocurrencies over the last few years. Our portfolio analysis reveals that diversification in cryptocurrency investment can be accomplished simply by employing the naïve equal-weighted scheme even when transaction costs are taken into account.     

石衡沧港城际铁路互联互通方案研究

突出功能定位,发挥路网互联互通作用,是高速铁路互联互通方案研究的关键。在阐述石衡沧港城际铁路互联互通现状的基础上,针对石衡沧港城际铁路客流特点和功能定位,分析石衡沧港城际铁路石家庄铁路枢纽、衡水铁路枢纽、沧州铁路枢纽和黄骅铁路枢纽等互联互通主要节点枢纽,通过衡水、沧州和黄骅铁路枢纽比选方案分析,提出石衡沧港城际铁路在通道中的枢纽方案,为区域连接线、城际铁路在方案互联互通作用提供研究支撑。     

A study on the deployment of high-speed broadband networks in NUTS3 regions within the framework of digital agenda for Europe

This paper investigates the high-speed broadband situation in the EU and its prospects. It uses a deployment model to estimate the investment required to meet the Digital Agenda for Europe (DAE) broadband targets set by the European Commission in its Europe 2020 strategy at different stages: as of 2016, after expected operators’ deployment, after public subsidies and leveraged investment, and as expected in 2020. The model uses data at the NUTS3 level, which is the most granular level that has data available on the status of broadband deployment, to arrive at a coherent and comparable framework. From the different perspectives on the investment to meet DAE targets, the paper concludes on the need for an appropriate combination of incumbent and alternative operators investments, public subsidies and leveraged investments, and new investments, both public and private and non-existing as of 2016, examining their feasibility and the impact of different regulatory, technical, and policy strategies.     

Study of emerging air taxi network operation using discrete-event systems simulation approach

This research focuses on understanding the air taxi operations to determine the number of air taxis required to fulfill the demand for urban air mobility in New York City (NYC). We leverage the Define, Measure, Analyze, Design, and Verify (DMADV) framework and integrate it with the systems simulation approach. Upon investigation, we find that all the parameters linearly impact the vehicle utilization, while other measures are robust, specifically with respect to the seating capacity. It is also recommended to operate initially with 70 air taxis in NYC to achieve a trade-off between customer wait time and vehicle utilization. The proposed approach can act as a recommender system for air taxi companies.     

Assessing the role of network topology in transportation network resilience

The abstract representation of a transportation system as a network of nodes and interconnecting links, whether that system involves roadways, railways, sea links, airspace, or intermodal combinations, defines a network topology. Among the most common in the context of transportation systems are the grid, ring, hub-and-spoke, complete, scale-free and small-world networks. This paper investigates the role of network topology, and the topology’s characteristics, in a transportation system’s ability to cope with disaster. Specifically, the paper hypothesizes that the topological attributes of a transportation system significantly affect its resilience to disaster events. Resilience accounts for not only the innate ability of the system to absorb externally induced changes, but also cost-effective and efficient, adaptive actions that can be taken to preserve or restore performance post-event. Comprehensive and systematically designed numerical experiments were conducted on 17 network structures with some relation to transportation system layout. Resilience of these network structures in terms of throughput, connectivity or compactness was quantified. Resilience is considered with and without the benefits of preparedness and recovery actions. The impact of component-level damage on system resilience is also investigated. A comprehensive, systematic analysis of results from these experiments provides a basis for the characterization of highly resilient network topologies and conversely identification of network attributes that might lead to poorly performing systems.     

Efficiency,total factor productivity and returns to scale in a sustainable perspective: An analysis in the European Union at farm and regional level

For global sustainability it is imperative to find a balance across the three main components of sustainable development which are the economic, social and environmental aspects. However, it is not a simple task to make these contexts compatible, usually because of economic pressures which transform them into opposed objectives. This framework occurs across several dimensions within society and the economy, where the agricultural sector is not an exception. The objective of this study is to analyse the efficiency, total factor productivity and returns to scale in an economic, social and environmental perspective in farms of the European Union (EU) regions through Data Envelopment Analysis (DEA) approaches. The research concerning the returns to scale will be complemented by the Keynesian models. Data obtained from the European Union Farm Accountancy Data Network (FADN) was considered. The results show that in maintaining or improving the levels of production in farms, it is often possible to greatly reduce, in some cases, the consumption of fertilizers and crop protection products. On the other hand, from a social perspective, some European Union regions are more generous in the salaries paid to farming workers and absorb more labour, which in a European context of unemployment, may be an interesting way to realistically look at and be engaged in the agricultural planning in a sustainable way, founding a balanced trade-off among the economic, social and environmental dimensions.     

环境与就业维度下出口商品结构优化——以江苏为例

利用计量方法从环境和就业这两个指标来考察江苏出口商品结构优化,其中环境指标主要是通过碳排放指标来体现的。通过研究发现江苏九大类出口商品在环境和就业指标上都无此消彼长现象,其中对两指标都具显著影响力的为机械及运输设备,化学品及有关产品和按原料分类的制成品这两类出口商品仅对环境有着显著影响力,对就业不具显著影响力,至于其他种类的出口商品则对环境和就业这两个指标都不具显著影响力,最后得出江苏出口商品结构优化的最明确方向,即大力促进机械及运输设备的出口,抑制化学品及有关产品和按原料分类的制成品这两类出口商品的出口。     

What hurts the dominant airlines at hub airports?

This paper estimates a frequency equation to explain the determinants of network airline service levels at their hub airports. Drawing on European data for 2002–2013, we find that network airlines reduce frequencies when the share of low-cost airlines increases both on the route and at the hub airport. On the contrary, frequency choices of network airlines are not affected by competition from low-cost airlines operating in nearby secondary airports. We also find some evidence that mergers in Europe may result in a re-organization of the route structure in favor of the hubs of the larger airline.     

Utilizing the access value of customers

Customers are critical resources for the success of any business, not only because they bring in sales and profits directly, but also because of their access value in a world that is becoming increasingly interconnected. However, the mechanisms by which the customer access value may be exploited and the implication for management has not been well understood. Access value can be defined as the worth of utilizing patrons for further marketing and sales of value-added or third party products. The access value, which mainly results from the aggregation of the customer base and customer data, is essentially a corporation's internalized asset. This article shows that the size of the customer base and the extent of engagement have a significant impact on the customer access value. To develop and gain the benefits of customer access value, traditional business models often need to be transformed: firms and platforms should provide free or subsidized products to attract people and then embed value-added products to make money. The success of the new business model depends on not only the right pricing and product strategies, but also an embedding strategy.