Roles of financial innovation and information technology: Lessons from US sub-prime mortgage crisis and its implications for China     

James H LENZER JR  Simon Xiaobin ZHAO 《中国地理科学(英文版)》2012,22(3):343-355

The mortgage loan has evolved from a local lending instrument into a major global security and its role is unparallel to other financial instruments in the process of financial globalization.This paper explains how technology and financial innovation transformed the mortgage loan from a local security into a premier global security traded worldwide.It examines the fundamental flaws of this process and why it does not work in regards to mortgage lending and the re-securitization products that were created through financial innovation.The findings show that regulation was unable to keep pace with financial innovation,which created an environment where actors in the financial service sector were able to behave geographically irresponsibly by using information asymmetries to their advantage by participating in moral hazard activities and engaging in other immoral and unethical business practices that were centered around localized geography,which ultimately contributed to the global financial crisis.It also examines the roll of financial innovation in regard to the Lehman Brothers Mini-Bond in Hong and its role as a driving force behind China’s newly emerging shadow banking sector.It concludes with a policy recommendation and its implication for China’s continued economic development.  相似文献   

Improvement of glacial lakes detection under shadow environment using ASTER data in Himalayas, Nepal     

CHEN Wenbo  FUKUI Hiromichi  DOKO Tomoko  GU Xingfa 《中国地理科学(英文版)》2013,23(2):216-226

The detection of glacial lake change in the Himalayas, Nepal is extremely significant since the glacial lake change is one of the crucial indicators of global climate change in this area, where is the most sensitive area of the global climate changes. In the Himalayas, some of glacial lakes are covered by the dark mountains′ shadow because of their location. Therefore, these lakes can not be detected by conventional method such as Normalized Difference Water Index (NDWI), because the reflectance feature of shadowed glacial lake is different comparing to the ones which are located in the open flat area. The shadow causes two major problems: 1) glacial lakes which are covered by shadow completely result in underestimation of the number of glacial lakes; 2) glacial lakes which are partly identified are considered to undervalue the area of glacial lakes. The aim of this study is to develop a new model, named Detection of Shadowed Glacial Lakes (DSGL) model, to identify glacial lakes under the shadow environment by using Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) data in the Himalayas, Nepal. The DSGL model is based on integration of two different modifications of NDWI, namely NDWIs model and NDWI she model. NDWIs is defined as integration of the NDWI and slope analysis and used for detecting non-shadowed lake in the mountain area. The NDWIshe is proposed as a new methodology to overcome the weakness of NDWIs on identifying shadowed lakes in highly elevated mountainous area such as the Himalayas. The first step of the NDWIshe is to enhance the data from ASTER 1B using the histogram equalization (HE) method, and its outcome product is named ASTER he . We used the ASTER he for calculating the NDWI he and the NDWIshe . Integrated with terrain analysis using Digital Elevation Model (DEM) data, the NDWI she can be used to identify the shadowed glacial lakes in the Himalayas. NDWIs value of 0.41 is used to identify the glacier lake (NDWIs≥0.41), and 0.3 of NDWIshe is used to identify the shadowed glacier lake (NDWIshe≤0.3). The DSGL model was proved to be able to classify the glacial lakes more accurately, while the NDWI model had tendency to underestimate the presence of actual glacial lakes. Correct classification rate regarding the products from NDWI model and DSGL model were 57% and 99%, respectively. The results of this paper demonstrated that the DSGL model is promising to detect glacial lakes in the shadowed environment at high mountains.  相似文献   

Review of shadow detection and de-shadowing methods in remote sensing     

AmirReza SHAHTAHMASSEBI  YANG Ning  WANG Ke  Nathan MOORE  SHEN Zhangquan 《中国地理科学(英文版)》2013,23(4):403-420

Shadow is one of the major problems in remotely sensed imagery which hampers the accuracy of information extraction and change detection.In these images,shadow is generally produced by different objects,namely,cloud,mountain and urban materials.The shadow correction process consists of two steps:detection and de-shadowing.This paper reviews a range of techniques for both steps,focusing on urban regions(urban shadows),mountainous areas(topographic shadow),cloud shadows and composite shadows.Several issues including the problems and the advantages of those algorithms are discussed.In recent years,thresholding and recovery techniques have become important for shadow detection and de-shadowing,respectively.Research on shadow correction is still an important topic,particularly for urban regions(in high spatial resolution data) and mountainous forest(in high and medium spatial resolution data).Moreover,new algorithms are needed for shadow correction,especially given the advent of new satellite images.  相似文献   

台特玛湖干涸湖盆区植物风影沙丘的形态特征   总被引：1，自引：0，他引：1  

蔡东旭  李生宇  刘耀中  俞祥祥  王海峰  雷加强  雷加强  武新成  彭琴  屈磊 《干旱区地理》2017,40(5):1020-1028

对台特玛湖干涸湖盆区盐穗木、柽柳和碱蓬3种植物风影沙丘的形态参数进行野外了测定,应用统计学方法,分析对比了不同植物风影沙丘的形态特征及阻沙能力。结果表明：（1）风影沙丘处于由沙嘴向沙堆演化阶段,沙丘形态参数间相关性显著（P<0.01）,其中沙丘高度与水平尺度相关性较好,沙丘垂向发育速度快于水平扩展。（2）风影沙丘与植物形态参数间亦存在相关性,受植物生物特性的影响,不同植物的相关性差异较大,其中碱蓬呈高度正相关（R>0.85,沙丘背风坡坡度除外）,盐穗木次之,柽柳灌丛相关性微弱。（3）在相同的区域环境下,3种植物的单株阻沙能力呈柽柳 > 盐穗木 > 碱蓬,盐穗木、碱蓬积沙量受株高影响较大,两者呈二次函数关系;柽柳积沙量主要取决于灌丛迎风剖面的面积。  相似文献   

云南金沙江流域水土流失直接经济损失测算方法与区域特征分析   总被引：4，自引：0，他引：4  

李云辉  贺一梅  杨子生 《山地学报》2002,(Z1)

应用环境经济评价理论与方法,定量地测算了云南金沙江流域水土流失(包括坡面侵蚀和重力侵蚀2个方 面)的直接经济损失,包括养分流失损失、水分流失损失和泥沙流失损失3项内容,并分析了水土流失直接经济损失 的区域特征,为该流域水土流失防治提供了基础依据。  相似文献   

峨嵋宝光研究之一—-宝光机理的综合研究          下载免费PDF全文

王鹏飞 《大气科学学报》2002,25(2):180-185

通过对宝光形成思路的追索,否定“冰晶云不可能出现宝光”的看法,综合考虑了不同条件下出现的宝光应遵循不同的形成机理。指出水云和冰晶云都能出现宝光,而冰晶云上宝光的伴生光象不是主虹,而是对日晕。  相似文献   

利用云下阴影实现陆地上空气溶胶和地表反射率的同时反演—理论方法和模拟   总被引：3，自引：0，他引：3  

段民征  吕达仁  崔克俭  郝文强 《遥感学报》2002,6(5):321-327

卫星探测信号包含大气中分子和粒子的散射贡献以及地表反射的贡献,在陆地上空二者的贡献相当,并且陆地地表反射率在时间和空间上极度不均一,因此,很难区分二者的各自贡献从而定量提取大气气溶胶和地表反射率,陆地上空气溶胶的反演也一直是一个极具挑战性的课题.而高分辨率卫星资料如TM5的可见光通道能够很好地区分云和云下阴影,如果云是不透光的,在阴影上空,卫星信号仅包含大气散射贡献和地表漫反射贡献,而在邻近的非阴影区上空,卫星探测信号还包含地表直接反射的贡献,根据这个原理,利用辐射传输模式分析了阴影区和非阴影区上空卫星探测的辐射量差别与地表反射率和大气气溶胶的关系,提出一种利用云下阴影来同时提取阴影上空大气气溶胶和地表反射率的单波长反演方案,并对气溶胶单次散射反照率,散射相函数,测量精度以及地表反射率的不均一性进行了敏感性分析.  相似文献   

正射影像上阴影和遮蔽的信息处理方法研究   总被引：3，自引：1，他引：3  

王树根  李德仁  郭泽金  郑精灵 《测绘信息与工程》2004,29(4):1-4

分析了正射影像上阴影和遮蔽现象的利弊双重性特点 ,讨论了正射影像上阴影和遮蔽处理的原则 ,简单介绍了基于光照函数分析和基于色彩空间分析的彩色航空影像阴影信息增强方法以及基于整体变分模型和基于纹理匹配的影像缺损信息补偿方法。试验表明 ,所提出的正射影像上阴影和遮蔽的信息处理方法是有效的  相似文献   

卫星可见光云图上日食阴影的动态订正     

张乐坚  王振会  裴晓芳  张红 《气象科学》2006,26(6):633-637

分析了日食对可见光云图及其时间序列的影响规律,提出利用相关分析、均值和方差分析以及线性拟合和局部增强等技术进行日食阴影区订正的动态方法。这种方法可以有效地消除阴影,尤其是日全食区域的“黑核”,较好地恢复了云图上云的纹理结构及亮度。  相似文献   

Tectonically induced climate and its control on the distribution of depositional systems in a continental foreland basin, Cloverly and Lakota Formations (Lower Cretaceous) of Wyoming, U.S.A.   总被引：1，自引：0，他引：1  

William S. Elliott Jr.  Lee J. Suttner 《Sedimentary Geology》2007,202(4):730-753

Continental sediments of the Cloverly and Lakota Formations (Lower Cretaceous) in Wyoming are subdivided into three depositional systems: perennial to intermittent alluvial, intermittent to ephemeral alluvial, and playa. Chert-bearing sandstones, conglomerates, carbonaceous mudrocks, blocky mudrocks, and skeletal limestones were deposited by perennial to intermittent alluvial systems. Carbonaceous mudrocks contain abundant wood fragments, cuticle and cortical debris, and other vascular plant remains representing deposition in oxbow lakes, abandoned channels, and on floodplains under humid to seasonal conditions. Intraformational conglomerates, sandstones, bioturbated and blocky mudrocks with caliche nodules, and bioturbated limestones characterize deposition in intermittent to ephemeral alluvial systems. Bioturbated limestones are encased in bioturbated mudrocks with abundant pseudo-slickensides. The presence of caliche nodules in some of the blocky to bioturbated mudrocks is consistent with supersaturation and precipitation of calcium carbonate from groundwater under semi-arid conditions. Caliche nodules, pseudo-slickensides, and carbonate-rich floodplain sediments are interpreted to have been deposited by intermittent to ephemeral alluvial systems under seasonal to semi-arid climatic conditions. Laminated mudrocks, siltstones, vuggy carbonates, bedded to nodular evaporites, pebbly mudrocks, and diamictites were deposited in evaporative alkaline lakes or playas. Pebbly mudrocks and diamictites are interpreted to represent deposition from channelized and unchannelized hyperconcentrated flows on a playa, resulting from intense rain events within the basin.The areal abundance and distribution of these depositional systems change systematically across the overfilled portion of the Early Cretaceous Cordilleran foreland basin in Wyoming. The lower part (A-interval) of the Cloverly and Lakota Formations is characterized by deposits of perennial to intermittent rivers that existed 300 to 1000 km east of the Sevier fold-and-thrust belt. Proximal to the Sevier fold-and-thrust belt, the A-interval of the Cloverly Formation and upper Ephraim Formation of the Gannett Group are typified by deposits of intermittent to ephemeral rivers and their associated floodplains. In the middle part (B-interval) of the Cloverly Formation, intermittent to ephemeral alluvial systems expand to 600 km into the basin. The upper part (C-interval) of the Cloverly Formation is characterized by playa deposits in the Bighorn and Wind River Basins and intermittent to ephemeral alluvial deposits along the front of the ancestral Sevier Mountains. Deposits of perennial to intermittent alluvial systems in the C-interval of the Cloverly and Lakota Formations are restricted to the Black Hills region, almost 900 km to the east of the Sevier Mountains. The change in the areal distribution of depositional systems through time within this continental foreland basin may be attributed to the development of a rain shadow associated with the uplift of the Sevier Mountains in the Early Cretaceous.  相似文献