基于光能利用率模型的河南省冬小麦单产估算研究

[目的]快速、准确估算空间尺度上作物产量,对于评价农田生态系统对气候变化的响应、制定科学合理的粮食政策、对外粮食贸易等具有重要意义。河南省冬小麦产量占全国1/4,准确估算河南省冬小麦产量对维护国家粮食安全具有重要作用。单产估算作为农作物估产中的关键技术,也是作物估产的难点之一。[方法]文章首先利用VPM(Vegetation Photosynthesis Model)估算冬小麦NPP(Net Primary Product),结合收获指数、冬小麦收获部分的含水量、含碳量、NPP分配到地上或地下部分比例等一系列符合该研究区的经验指数,进行河南省冬小麦单产估算研究,并分析了引起模拟误差的原因。[结果]模拟单产较实测单产低估4.4%(实测单产为6 810kg/hm~2,模拟单产为6 519kg/hm~2),但两者之间存在显著相关关系,两者相关系数的平方R2=0.70(n=50,p0.01)。通过与MODIS-GPP产品获得的冬小麦单产数据比较,基于VPM模型的模拟结果优于MODIS-GPP产品。[结论]基于VPM可快速、准确估算河南省空间尺度冬小麦单产,该方法具有较好的适用性。     

Activation and variation of the United Nation’s cluster coordination model: a comparative analysis of the Haiti and Japan disasters

The coordinated response to extreme events is critical as illustrated by recent disasters in Haiti and Japan. As a way for coordinated provision of international humanitarian assistance to disaster-hit countries, the Office for the Coordination of Humanitarian Affairs (OCHA) developed cluster coordination model (CCM). With content analysis and network analysis of OCHA situation reports, this study checked four premises regarding activation of CCM, interaction between national and international actors, roles of proximity country, and level of cluster coordination. This study found that there were meaningful variations in implementing the CCM for 2010 Haiti and 2011 Japan disasters. From the analyses, we found that the current CCM may be vulnerable to black swan disasters; thus, extensive and active estimation of national disaster management capacities should be conducted to prevent collapse of national disaster management system. However, the reconciliation of state sovereignty and international humanitarian assistance also should be considered.     

威客活动水平的区域空间统计分析——从人力资本视角看区域经济发展失衡

探索了威客活动的地域分布特征,并将之与区域经济发展水平相联系,构建了区域经济发展研究的新视角。通过绘制分位地图,探索了威客活动可能存在的地域歧视,从需求和供给的角度分析了威客活动的地域分布情况。利用空间统计分析方法对比了GDP与威客数量的地域分布情况。研究结果表明:威客活动中不存在明显的地域歧视;威客活动的需求和供给分布较为一致;大多数省份的威客数量水平低于其经济发展水平;威客的地域分布不存在明显的集聚现象。整体而言,以威客平台为基础的网上劳动力市场的存在与发展,借助互联网在联系不同地域、消除地域差异上起到了重要作用。     

Forecasting China's GDP growth using dynamic factors and mixed-frequency data

Forecasting GDP growth is important and necessary for Chinese government to set GDP growth target. To fully and efficiently utilize macroeconomic and financial information, this paper attempts to forecast China's GDP growth using dynamic predictors and mixed-frequency data. The dynamic factor model is first applied to select dynamic predictors among large amount of monthly macroeconomic and daily financial data and then the mixed data sampling regression is applied to forecast quarterly GDP growth based on the selected monthly and daily predictors. Empirical results show that forecasts using dynamic predictors and mixed-frequency data have better accuracy comparing to traditional forecasting methods. Moreover, forecasts with leads and forecast combination can further improve forecast performance.     

高校贷款融资风险评估与预警模型研究

创新高校贷款风险评估与预警模型,共筑财务系统"防火墙"。通过深入剖析高校债务风险凸显成因、影响路径及其特殊性,探索建立一套系统性强、涵盖面广、操作性强的风险评估与预警模型。并实证研究分析福建省A高校实施新校区项目所面临贷款规模、风险评估等问题,切合实际提出对策建议,为政府、高校和银行共同防范债务风险提供理论与实证依据,形成防范债务风险合力,促进高校健康、稳定、可持续发展。     

基于OECD 国家面板数据的金融风险影响 因素研究

本文选取1980~2013年OECD 28个国家经济与金融的样本数据,采用面板logit模型对这些国家金融风险的影响因素进行逐步回归分析。结果显示,GDP增长率、经常账户余额占GDP比率以及总储备占GDP的比率对OECD国家金融风险的影响是负向的,即随着它们的增长,金融风险产生的概率减小;汇率对OECD国家金融风险的影响是正向的,即随着汇率的增长,金融风险产生的概率增大。     

四川省重点生态功能区有机农业生产效率研究——基于三阶段DEA模型的实证分析

[目的]有机农业为我国农业绿色发展起到良好的带动作用,但我国有机农业发展中,西部贫困地区较为滞后。针对西部贫困地区有机农业生产效率进行定量分析,揭示影响有机农业生产效率的主要因素,旨在提高该地区有机农业生产效率,丰富区域视角下的有机农业生产研究。[方法]采用三阶段DEA模型对2014年四川省重点生态功能区有机农业生产效率进行量化分析,识别环境变量对有机农业生产效率的影响。[结果]环境因素和随机误差对四川省重点生态功能区有机农业生产效率产生了显著的影响。环境因素中,农民人均纯收入的增加有利于促使农机、耕地等资源的有效利用,但同时也导致化肥投入冗余增加;城镇化率的提高会降低耕地、劳动力、化肥、农药等使用效率,从而对有机农业生产效率产生不利影响;财政支出占GDP比重的增加有利于提高农机使用效率,但同时也导致化肥和农药投入冗余增加;粮食播种面积占耕地面积比重对有机农业生产效率产生了不利影响。剔除环境因素和随机误差的影响后,四川省重点生态功能区各县平均技术效率和规模效率有所下降,纯技术效率则略有提升。基于纯技术效率和规模效率,四川省重点生态功能区各县有机农业生产效率可分为"双高型""高低型""低高型"和"双低型"等4种类型。[结论]三阶段DEA模型有效剔除了环境因素和随机误差对有机农业生产效率的影响,估计的效率值更真实地反映了四川省重点生态功能区有机农业生产效率水平。针对四川省重点生态功能区各县有机农业生产效率的不同特征,应结合地方实际,通过扩大要素投入规模或改进要素配置效率和使用效率,提高有机农业生产效率。     

Modelling the preference for business charter in the cross-strait market

This paper aims at investigating business travelers' choice behavior between business charter (BC) and the business class of commercial airlines in the cross-strait market. This study applies the stated preference method and sets five scenarios with the combination of various levels of fares, waiting time, privacy and expedient clearance services and inflight communication equipment. Data were collected by purposive sampling and interviewing business travelers near the VIP centers, departure lounges, and the baggage claim areas of Taiwan Taoyuan International Airport. A sample with 420 business travelers from Taipei to Shanghai was collected. Then, the binary logit model was employed to analyze how service attributes influence Taiwanese business travelers' choice behavior between BC and business class. Estimation results indicate that fare is the most important factor. Other factors such as gender, seniority, and the number of business trips during the previous year remain significant on the probabilities of choosing BC. Additionally, five specific features of BC were set as dummy variables in the model. Those are transfer time saving, travel time controlling, client entertainment, customer visits and international conference attendance. All of them have positive effects on the preference for using BC.     

Assessment of land use compatibility and noise pollution at Imam Khomeini International Airport

This study aimed to investigate land use planning around airports, by employing Remote Sensing (RS) and Geographic Information Systems (GIS), in conjunction with an optimization algorithm using an Integrated Noise Model (INM) software, to establish the potential effects of aircraft noise at Imam Khomeini International Airport (IKIA) in Tehran. We also checked for land use compatibility with the noise levels around IKIA and the residents' reaction to the noise. The research was carried out in three stages: a) the establishment of Strategic Noise Map (SNM) scenarios of the airport operation in the years 2011, 2020 and 2030 using the INM software; b) the assessment of the results with emphasis on the study area land uses and application of RS and GIS and the exposure of residents at different levels of environmental noise; and c) the assessment of the intensity of aircraft noise annoyance at various times of day and night. The results indicated that developing IKIA together with the residential development will increase airport noise. Hence proper management and control of noise at IKIA is essential.     

Air express network design based on express path choices – Chinese case study

Due to the shortage of cargo aircraft, Chinese express companies have to provide transportation services with a hybrid method that consists of “rented bellies and self-owned cargo aircraft”. Because the bellies are rented from air passenger companies and because the cargo aircraft are owned by the express companies, it is important for the express companies to use their cargo aircraft as effectively as possible. This paper constructs a bi-level model to optimize the flight transportation network of an express company. The upper model designs the network and allocates the transportation capacity with the objective of minimizing the total transportation cost, and the lower model calculates the link flows in user equilibrium. Data from ShunFeng (SF) Express Company (China) are used to conduct the case study. Using the model outputs, the flows on links and at nodes are analyzed to illustrate the transportation and transshipment situations.