Air traffic forecast and its impact on runway capacity. A System Dynamics approach

The uninterrupted growth of air traffic in Colombia has been reinforced since the 1990s by a public policy of liberalization of airspace, and by redirecting public and private investment towards the modernization and updating of airport infrastructures, giving in concession the busiest airports in the country, 19 to date. In the commercial air sector, and in this same period, the flag airline was privatized and new air operators, including low cost airlines (LCC), entered the market. Since 2012, air fares are completely deregulated. Consequently, in the last two and a half decades, passenger transport in Colombia grew by 863%. This important growth rate has been driven and led by the country's main airport, the Bogotá-El Dorado International Airport (BOG), in the capital of Colombia. But some technical reports consider the airport will reach its maximum capacity in the short term mainly because of its inability to expand its airfield (runway system). Due to this circumstance, the aeronautical public authority of Colombia gave course to the planning, design and construction of a new airport (complementary) on the outskirts of the city of Bogotá, which will enter the design phase in 2026/2027. Therefore, it is considered suitable the development of a traffic forecast for BOG in the medium term and to evaluate the impact of future demand on the runway capacity of the airport. Then, and due to the complexity of the air transport forecast, the use of System Dynamics (SD), is considered to be appropriate as an analysis approach. System Dynamics is based on feedback control theory and it is equipped with mathematical computer simulation models, which uses linear and non-linear differential equations. The results suggests a need to expand the airport case study (runway system) after mid-2019, where the current capacity utilization factor is around 100% and two to three runways will be required for the normal operation; after October 2022 the number runways required is set to three until the last period simulated (2023).     

县域农业资源承载力评价预警系统构建初探

[目的]建立农业资源承载能力评价预警系统,加快提升农业资源环境管控能力,是调结构转方式、推进农业绿色发展、建设美丽中国的重大举措。[方法]按照绿色发展理念,以"驱动力—压力—状态—影响—响应"(DPSIR)理论为基础构建农业资源承载力理论模型。[结果]以县域耕地和草地为研究对象,提出了基于承载体变化态势的农业资源承载能力评价预警思路;建立了农业资源承载力评价指标与综合集成评价方法、农业资源超载类型和预警等级划分体系;设计了农业资源超载成因解析准则和承载力调控政策创新方向。[结论]基于承载体视角的资源承载力评价预警系统适用于开放的县域农业资源管理;建立健全农业资源监测体系和资源台账,面向评价预警需求长期积累专题数据,突破"数据短板"。     

Territorial state capacity and elite violence from the 6th to the 19th century

We present new evidence for elite violence using regicide, the killing of kings, and investigate the role of the state in European violence between the 6th and 19th centuries. First, regicide is critically assessed as a proxy for interpersonal elite violence. Second, we propose ‘territorial state capacity’ as a measure of states being able to keep or even expand their territories. We find a negative correlation between the changes in territorial state capacity and the changes in elite violence. This could be interpreted in two ways, either that growing territorial state capacity enabled human society to reduce violence, or that a higher regicide rate resulted in lower territorial state capacity. Another possibility would be a bidirectional mechanism that resulted in a co-evolution of the two variables.     

以企业文化建设提升企业核心竞争力的思考

本文分析了企业文化与企业核心竞争力之间的关系,探讨了如何通过建设优秀的企业文化来提升企业核心竞争力的策略。     

中国工业产能利用率--基于企业数据的测算

通过测算中国工业近年来的产能利用率水平,发现工业总体产能利用率处于一个80％左右的合理的水平上,但部分领域,如政策倾斜区域和扶持性产业的产能利用率偏低,说明在很大程度上人为的投资行为在造就较高的增长速度的同时也带来了严重的产能过剩问题。由此可见,违背市场信号的资源配置的帮扶刺激政策虽然可以在短期内提高产出水平拉动经济增长,但引致的产能过剩和资源错配带来了更大的效率损失并成为长期增长的制约。     

我国科技基础设施的指标构建及评价研究

科技基础设施是技术创新的先行基础,成为各国创新发展的战略重点。文章基于因子分析法构建科技基础设施指标体系,并结合聚类分析对我国2013年30个省份科技基础设施的发展现状及创新能力进行综合测评。结果显示,我国科技基础设施的发展存在明显地域差异,且区域创新能力的驱动力可分解为强知识型、强物化型、偏知识型、偏物化型和无偏向型科技基础设施发展模式。因此,充分发挥不同梯度科技创新圈的辐射带动作用,建立开放的科技基础设施创新网络体系是提升我国创新能力的有效途径。     

基于创新系统理论的中小企业技术创新支持体系

依据创新系统的结构和特征,构建基于创新系统理论的中小企业技术创新支持体系的设想。完善的中小企业技术创新支持体系应由法律支持体系、联合创新的政策支持体系、技术创新服务支持体系、金融支持体系、财政税收支持体系等构成。     

我国政府间财政能力及其均衡制度研究

构建社会主义和谐社会离不开政府间财政能力的均衡配置。虽然财政能力均衡理论在国外已有50多年的历史,且均衡制度已比较完善,但我国以转移支付为主要内容的财政能力均衡制度建设还处于起步阶段。我国政府间财政能力纵向配置和横向配置的实证分析结果表明,我国转移支付制度的效果不佳,还存在着许多问题。这就需要我们借鉴国外的财政能力均衡制度来完善我国的政府转移支付制度。     

国内外丙烯市场近况及发展趋势

本文阐述了世界丙烯及其衍生物的产能需求现状和预测,以及我国丙烯产能需求现状和预测。     

Marketing and Technological Absorptive Capacities: Environmental Antecedents and Performance Outcomes in High-Tech Firms

Purpose: This article investigates marketing and technology absorptive capacities as distinct types of external knowledge while considering three environmental conditions, namely uncertainty, munificence, and heterogeneity and two distinct outcomes, namely innovation and financial performance.

Methodology/approach: Using a quantitative approach, the authors analyze data from 141 Israeli business-to-business high-tech firms.

Findings: The data mostly supported the hypotheses. Empirical findings imply that an uncertain environment is a precursor for a strong effort to develop a technological absorptive capacity and, to a lesser extent, a marketing absorptive capacity. Technological and marketing absorptive capacities were found to be distinct constructs with positive impacts on financial and innovation performance. Marketing absorptive capacity had a stronger impact than technological absorptive capacity on financial performance. Surprisingly, marketing absorptive capacity was negatively associated with innovation performance.

Originality/value: This study attempts to overcome some limiting assumptions of absorptive capacity theory that have contributed to its reification in order to make three theoretical contributions. First, it distinguishes between marketing and technological absorptive capacities. Second, it tests differential responses of the two absorptive capacities to environmental contingencies. Third, it compares the differential impacts of marketing and technological absorptive capacities on financial and innovation performance.