基于不同Logistic模型的土地利用格局模拟对比研究——以湖北省宣恩县和咸丰县为例

模拟土地利用空间格局分布规律对合理利用土地资源、制定土地利用规划、协调土地与经济、环境的关系具有十分重要的意义。土地利用格局存在空间异质性,对比不同地区格局特征规律对加深土地利用格局的认识具有重要意义。以邻接的湖北省宣恩县和咸丰县为研究对象,通过对比基于局地因子、自相关因子和邻域因子的3种Logistic模型的模拟参数的一致性和异质性来对比研究两地的格局分布规律。实验与分析结果表明,宣恩县和咸丰县的土地利用格局特征存在共同的驱动因子和聚集效应,具有共性;不同模型的模拟结果表明驱动因子在作用方向,大小方面存在差异,邻域因子在邻域尺度上表现出不同特征。研究结果对加深理解不同地区的土地利用分布格局特征的差异性,促进区域土地利用的规划、土地资源的合理开发与可持续发展战略的顺利实施具有一定的参考价值。     

Ratio-based design hour determination for airport passenger terminal facilities

To avoid both over-design and under-sizing of airport passenger terminal facilities such as security checkpoints, the infrastructure is designed for a specifically determined design load. As such, the design load is considered for a short period of time, usually an hour of operation, during which peak, though not necessarily maximum, demand occurs. For strategic planning applications, future design loads can be determined by either fictitious flight schedules or ratio-based models which forecast the relationship between design load and annual demand. This study presents two ratio-based methods which allow the direct determination of design hour loads (DHL) for passenger terminal facilities. The unsaturated DHL model considers the relationship between observed passenger flows in the terminal and aggregated annual demand data. The saturated DHL model includes several operational constraints which limit the actual DHL, such as limitations in the runway system or the fleet mix operating at an airport. Both models are applied to two real-world airports, for which the DHL of the security checkpoint facilities is estimated from large datasets covering multiple years. Results are significant at the 5 % level and suggest that the proposed ratio-based methods are appropriate for airport strategic planning applications.     

How can investors build a better portfolio in small open economies? Evidence from Asia’s Four Little Dragons

This study investigates the role of hedging and portfolio design among stocks, exchange rates, and gold in small open economies (SOEs) from 4 January 2000 to 31 March 2020. We adopt the trivariate dynamic conditional correlation-fractionally integrated asymmetric power ARCH model and unconditional quantile regression model, and our findings show that the hedging role of the U.S. dollar (USD) and gold against stocks differs under regular and extreme market conditions. The USD can act as a powerful hedge asset for stocks in regular market periods. Moreover, during the global financial crisis and COVID-19 outbreak, the safe-haven effect of gold becomes stronger for almost all stocks, whereas the USD can serve as a strong safe haven against stock markets of Korea, Taiwan, and Singapore when stock returns are extremely low. In terms of portfolio designing, we find that adding the USD and gold to portfolios improves their hedging effectiveness, and the optimally weighted stock-USD-gold portfolio is the best portfolio strategy, irrespective of referring to return or risk.     

农业农村双创工作的成效机制研究

[目的]近年来,创新创业的热潮大力兴起,如何对农民双创工作的成效机制进行研究,成为文章研究的重点。通过对农民双创工作中的创业者特征、创业者关系、政策适应与农业农村双创收益机理的研究,找出创业企业绩效演变机理。[方法]收集2017年2—5月重庆24个地区1 855位农民的调查问卷,采用专家评价法对双创收益、创业培训、创业者社会关系和创业政策适应的测量项目进行因子分析。[结果]对农民双创收益的影响因素进行分析讨论,得出学历水平、创业动机、创业风险意识、创业经营模式以及创业培训均对双创收益的提升有促进作用;创业者特征回归分析中R~2值由0.22提升为0.32,ΔR~2的值为0.34,说明自变量对因变量有预测作用;创业者特征对双创收益值为0.329,说明创业者的特征越高,其创业的绩效就越高;创业政策回归分析中R~2值由0.12增加到0.22,ΔR~2的值为0.14,说明自变量对模型有预测能力,且政策越全面有效,对农民的双创收益提升效果越好;创业者社会关系回归分析中R~2值由0.098提升为0.175,ΔR~2由0.175增长为0.433,说明创业者的社会关系越好,农民的双创收益越高。[结论]研究结果说明农业农村双创工作中创业者特征、创业者社会关系以及政策适应可提升创新创业机制的完善,提升双创收益。     

Comparison of public perception and risk management decisions of aircraft noise near Taoyuan and Kaohsiung International Airports

This study uses multiple linear regression to identify factors contributing to perceived risk among residents near Taoyuan and Kaohsiung International Airports, the effect of perceived risk on their willingness to reduce risk, and consumption preferences that can reduce risk. Results indicated that residents' risk perception near Taoyuan Airport is lower than that near Kaohsiung Airport. Noise pollution experience, perceived probability of environmental contamination and negative effects, and perceived severity of catastrophic consequences significantly increase residents' perceived risks. Residents are willing to recognize and participate in mitigating the risks of aircraft noise pollution. The more risk residents perceive, the more willing they are to participate in disaster reduction and investigate means of improving the risk environment.     

Bancarization and violent attacks from guerrilla and other illegal groups in Colombia

Income shocks affect violence through the opportunity cost and rapacity effects. Existing studies focus on the impact of transitory shocks, especially commodity price innovations. This paper builds on this literature and studies the causal effect of permanent income shocks on armed conflict in Colombia. Using a rich dataset reporting all guerrilla and other armed groups' attacks by municipality between 2009 and 2014 and information on the provision of banking services, it shows that increasing bancarization leads to reductions in violence. These results have important implications for public policy in countries with a long history of violence. They suggest that promoting financial inclusion is useful for reducing conflict.     

村级尺度耕地产能空间分异及其影响因子分析

[目的]通过探究耕地产能空间分异规律与影响因子,识别地区粮食生产关键制约因素,提升高标准基本农田建设的针对性和建设效果。[方法]采用空间自相关模型刻画了村级尺度耕地产能空间分异规律,对比分析了线性回归模型和地理加权回归模型在耕地产能影响因子识别的效果,并依此划分产能提升类型区。[结果](1)海伦市耕地产能呈现中西部高北部偏低的态势,且具有较强的空间自相关特征。(2)海伦市耕地产能与黑土层厚度、出现障碍层深度、耕作距离、田块状况和质地等变量显著相关,且均呈正相关,但在空间上表现出不同程度的异质性。(3)基于地理加权回归模型的耕地产能影响因子,提出了产能保持区、耕作条件改良区、质地改良区、障碍层改良区和保护性耕作区5类耕地产能提升类型区。[结论]文章所采用的基于村级尺度耕地产能及其空间分异因素模型相关研究,能够较好揭示村级耕地产能空间分布特点、空间自相关性特征及影响因子分布特征,基于此所划分的耕地产能提升类型区较已有研究对耕地分类管理具有更精准的支撑作用。     

How do “gatekeepers” affect credit risk?

This study investigates the relationship between auditor tenure and credit default swap (CDS) spreads of U.S. firms based on quantile regression. After allowing for common determinants of CDS spreads, auditor tenure exerts both statistically and economically significant additional impacts on the CDS market. Furthermore, there are differential effects of common CDS spread determinants and auditor tenure. While common determinants of CDS spreads (e.g., leverage, volatility, risk free rate, credit ratings, and earnings) have monotonically increasing impacts when CDS spreads (and their changes) are increasingly higher, auditor tenure primarily has the impact when CDS spreads are of low or median levels for less risky firms.     

重庆市乡村旅游资源空间特征及其与乡村振兴关系研究

[目的]探究重庆市乡村旅游资源的结构类型和空间特征,分析乡村旅游资源数量与乡村振兴之间的关系,对重庆市乡村旅游产业发展和促进乡村振兴具有指导意义。[方法]文章利用GIS技术定量分析重庆市乡村旅游资源的空间分布特征,通过空间分布模型探究乡村旅游资源空间分布的聚集程度,利用地理联系率探析人口规模和经济发展水平与乡村旅游资源分布的配合度。采用回归模型从整体上对重庆市乡村旅游资源数量与乡村振兴的关系进行分析,利用Pearson相关系数对不同经济发展区域关系进行研究,试图得到乡村旅游资源数量与乡村振兴的辩证关系。[结果]重庆市乡村旅游资源具有4种类型,农事体验类所占的比重最大,达到43.46%,乡村文化类所占比重最低为2.30%。乡村旅游空间布局特征结果表明重庆市4种乡村旅游类型在空间上的分布存在较大的区域差异,都呈现集中分布, 4种类型的景点与人口和经济的配合度较高。回归分析结果表明,乡村旅游资源数量与休闲农业和乡村旅游接待人次、农村卫生厕所普及率、村综合性文化服务中心覆盖率、县级以上文明村和乡镇占比和农村居民人均纯收入之间存在均衡关系。Pearson相关性分析结果表明除休闲农业和乡村旅游接待人次外,乡村旅游资源数量仅与农村居民人均纯收入之间存在低度相关性,不同经济区相关系数差异较大。[结论]综合以上研究结果,乡村旅游资源的空间分布特征既受当地经济发展的影响,同时又促进当地经济的发展,表明重庆市乡村旅游资源对乡村振兴具有一定的促进作用。建议在今后的发展中应拓展乡村旅游类型,提高乡村文化类景点的数量和比重,促进重庆市乡村旅游产业的均衡发展,实现不同经济区乡村经济的协调发展。     

农户收入分化对林地流入与流出意愿影响研究

以辽宁省409户样本农户问卷调查为基础,采用描述性统计分析农户收入分化在农户年龄层次、受教育程度、家庭劳动力数量等方面的差异化特征,并运用二元Logistic回归模型分别讨论收入水平分化、收入结构分化、二者交互项对农户林地流转综合意愿、流入意愿、流出意愿的差异化影响。结果表明:农户收入水平分化对林地综合流转意愿、林地流入意愿具有显著正向影响;农户收入结构分化对农户林地流出意愿具有显著正向影响;农户收入水平分化与结构分化交互项对农户林地综合流转意愿、林地流出意愿具有显著正向影响。因此,需要关注农户收入分化因素;做好收入分化因素的有效识别;充分认识收入分化因素对农户林地流入与流出意愿的差异影响;把握分化特征,有针对性提高林地流转意愿。