基于GIS和RS的蓄滞洪区和谐发展的技术路线

应用遥感与地理信息系统技术构建基于GIS模型的蓄滞洪区空间数据库,对蓄滞洪区内的基础地理数据进行存储、管理,并对空间数据进行可视化和空间分析等操作;运用RS技术对蓄滞洪区内的土地利用、生态环境变化等情况进行动态监测,建立蓄滞洪区发展指标体系;探求蓄滞洪区的和谐发展模式,为蓄滞洪区的可持续发展提供科学依据。     

SHIRKING,STANDARDS AND THE PROBABILITY OF DETECTION

By relaxing the common efficiency wage assumption of exogenous shirking detection probabilities, we demonstrate how standards and efficiency wages are related. In a more general setting where the probability of detection depends upon the equilibrium effort level of non‐shirkers, we show that the uniformly positive (negative) supply‐side relationship between wages (unemployment insurance) and effort is no longer guaranteed. Profit maximization on the part of the firm, however, ensures that effort will depend positively (negatively) on wages (unemployment insurance) in equilibrium.     

Police-Monitored Cameras and Crime*

We study the effects of police monitoring on crime. We exploit detailed information on the location and date of installation of police-monitored surveillance cameras, coupled with data at the street-segment level on all reported crimes in the city of Montevideo, Uruguay. We find that the introduction of police-monitored surveillance cameras reduces crime by about 20 percent in monitored areas relative to a pure control group located outside the city. We also explore potential displacement effects, and we do not find evidence of such effects.     

Decomposing financial (in)stability in emerging economies

The analysis of the build-up of risks in emerging economies have traditionally been scarce and focused mostly on external risks, despite the recent substantial development of their financial system. This paper builds an index of financial vulnerabilities tailored to emerging economies, grouping 32 indicators around four poles: valuation and risk appetite, imbalances in the non-financial sector, financial sector vulnerabilities, and global vulnerabilities. It adopts a model-free approach, purposely departing from early warning models or complex econometric constructs, and rely on data made already available by international organisations. Our index of financial vulnerabilities enables a granular mapping of where risk originates and how it spreads to other parts of the financial system. Using various data visualisation tools and benefitting from the flexibility of our index’s methodology, we are able build a narrative of the evolution of financial stability in emerging economies from 2005 to 2015. Finally, we also discuss the relation between our index and both the business cycle (proxied by GDP) and the credit cycle (proxied by the credit-to-GDP gap).     

基于底线预警的国土空间生态修复规划实施监督体系研究

国土空间生态修复是推进生态文明建设的重大举措，构建基于底线预警的国土空间生态修复规划实施监督体系是完善国土空间规划“一张图”信息系统的重要组成部分和政策支撑。通过对生态修复规划实施监督体系建设的研究，把握底线控制与监测预警机制，对接国土空间生态修复业务管理各项需求，搭建“五梯度四体系”的生态修复规划动态监测实施监督信息系统，构建以“七个一”为主要内容的生态修复规划底线预警监测评估机制，并与各层级国土空间规划“一张图”实施监督信息系统进行衔接，实现对生态修复规划实施的动态监测和预警。     

The effects of credit default swaps on corporate investment

ABSTRACT

This paper examines how credit default swaps (CDS) affect the corporate investment of the referenced entities. We document a significant reduction in corporate investment after CDS trading, a result that is robust to alternative model specifications and a set of endogeneity tests. Our findings of the increased firm risk and cost of capital support the costly external capital channel. The cross-sectional variations in CDS effects demonstrate that both reduced monitoring and the empty creditor problem might be the underlying forces driving the costly external capital channel. Our additional analysis implies that CDS trading is associated with an enhancement in investment efficiency for firms that are prone to overinvestment.     

面向规划管理的国外国家公园监测体系研究及启示——以美国、加拿大、英国为例

监测对于国家公园的科学保护管理与规划具有重要意义。中国正处于国家公园体制建设初期，有必要深入研究如何建立国家公园监测体系。以近20年来发展迅速的美国、加拿大和英国的国家公园监测体系为研究对象，基于文献调查和比较分析，从监测内容框架与指标、数据管理与转化、组织和保障3个方面梳理在各自资源与管理背景下国家公园监测体系的基本特点，并提取出面向规划管理的国家公园监测体系建设的16个基本要点，为我国提供借鉴和启示。     

剖线强度梯度变化的作物软硬变化区精确划分

[目的]软硬变化区的划分是进行遥感变化检测技术识别农作物的基础。为解决人工判读方法中存在人为主观因素影响以及自动判别和交互式判别方法对不同研究区的适用性问题,该文提出基于剖线梯度变化(Profile based Gradient Change Magnitude,PGCM)进行软硬变化区划分的方法。[方法]该研究选择破碎农业景观种植区域为研究区,计算拔节期Quick Bird影像和播种期模拟影像两个时相的变化强度,从作物地块内部向外绘制剖线,利用剖线强度的梯度变化确定硬变化区(Hard change region,HCR)、软变化区(Soft change region,SCR)和未变化区(Non change region,NCR)3者间的划分阈值。[结果]从识别结果来看,PGCM能够有效在地块边界处探测到软变化像元,进而确定HCR、SCR。像元分辨率在5~60 m不同尺度下,识别HCR区混入比例为11%~16%,混入比例随着分辨率下降而降低;NCR区混入比例为3%~4%,受分辨率尺度影响不大;SCR区识别比例为74%~86%,识别精度较高,识别结果与冬小麦空间分布结果保持一致。[结论]PGCM方法能够自动、便捷地确定阈值,摆脱人工判定的主观性,有效地划分出HCR、SCR和NCR 3个区域,为进一步HCR、SCR区内的作物识别提供基础。     

无人机遥感系统的研究进展与应用前景

对于无人机遥感来说,融合了无人机技术与遥感技术。在无人机遥感技术应用的过程中,涵盖了诸多不同类型的先进技术,比如,无人机驾驶飞行技术、通讯技术、遥感传感器技术等,存在着显著的智能化、自动化等不同方面的特征,能够迅速得到相关资源,并且系统掌握国土、环境等不同方面的信息,然后加以实时化处理,通过建模与科学分析,能够制定出无人机遥感技术运用的具体策略,凸显出其良好的功效。本文针对无人机遥感系统的研究进展进行了详细地分析,同时说明了无人机遥感系统的应用前景,进而对有关研究人员形成一定的启发。