Period-Luminosity Relations for Classical Cepheids

BVIJHK period-luminosity relations for classical cepheids in the galaxy and magellanic clouds which pulsate in the fundamental mode are obtained on the basis of four samples. The period-luminosity relations for the BVI bands obtained here are more accurate than the analogous relations existing up to the present. Period-luminosity relations in terms of W functions are also obtained for these samples and have the same accuracy as the currently existing analogous relations.     

Deservedness, development, and the state: Geographic categorization in the US Agency for International Development’s Foreign Assistance Framework

The institutions, practices, and discourses of US development policy and foreign assistance are undergoing profound changes. Central to these has been the creation of a new framework for foreign aid, built around a complex taxonomy of developing states and governance issue areas, with geographic and governance categories predicated on notions of state stability and fragility, strategic geopolitical position, and development progress. Given its long-standing position as the primary federal agency responsible for development and foreign aid, the US Agency for International Development (USAID) has played an important role in these policy changes, even as its political status and standing have suffered in recent years. The new framework is beset by contradictions, stemming both from the problematic relationship between development, security, and liberalization in agency rhetoric and strategies, and from intensive restructuring processes affecting USAID’s internal character and external relations. This paper investigates the new framework for foreign aid, linking internal restructuring at USAID to broader trends in state development strategies. I argue that shifts in US development and aid policy - toward emphases on “transformational development” abroad and centralization over strategic decision making domestically, crystallized in the new framework - are based in contradictory understandings of aid deservedness that stem from the tensions between economic and geopolitical aims within the current security-focused US state project of neoliberalization. These contradictions and tensions are displaced onto USAID via the Foreign Assistance Framework.     

移动区域时空关系变化建模研究

针对二维欧氏空间内的移动区域对象在时空关系变化建模中存在的问题,该文提出了一种时空关系变化序列模型,并建立了时空关系变化概念邻域图。采取基于时间片的时空数据模型,通过分析移动区域间随时间变化的拓扑、距离和方位关系,解决时空关系变化的集成建模问题。该方法能有效刻画移动区域的动态时空特征。     

引入二维交细分类型的地表覆盖矢量数据增量更新

通过遥感影像与基准年数据对比获得变化信息是目前地表覆盖数据增量更新的主要变化数据来源,但现有方法不能直接更新地表覆盖矢量数据。本文设计了一种包含变化对象的空间位置和类型信息的地表覆盖增量数据模型,发展了一种引入面/面二维交细分类型的地表覆盖矢量数据增量更新方法。该方法首先采用基于目标整体交、差结果的欧拉数的E-WID层次拓扑关系模型区,分析了地表覆盖矢量数据更新中的14种二维交细分拓扑关系类型;然后根据这些二维交细分类型,设计了9条自动更新处理规则。最后开发了一套基于根据二维交细分类型处理规则的地表覆盖数据增量更新原型系统,并用实际数据验证了其正确性。     

Prelude to Brazil: Leo Waibel's American Career as a Displaced Scholar

Beyond Germany, Leo Waibel (1888–1951) built a distinguished reputation for his work in Africa and the Americas. Today he is remembered especially in Brazil, where he boosted the development of geography as a research discipline in the years 1946–1950. During his tenure of the chair in geography at Bonn (1929–1937), Waibel's main research preoccupation became the role of the tropics in the world economy. In early 1937, he sought research leave to make an extended field trip to Brazil. Stripped on political grounds in the same year of his chair, Waibel came to the United States, where he became the only geographer to receive help from the Emergency Committee in Aid of Displaced Foreign Scholars. He would eventually serve as one of the very limited core staff on President Franklin Roosevelt's “M” Project on migration and settlement. This paper reconstructs the context of his work in the United States, clarifying especially the nature of his collaborations with Isaiah Bowman, widely regarded at the time as the leading geographer within the United States. Waibel's correspondence from the United States, and later from Brazil, reveals an international career marked by contradictions.     

Spatial inequality of foreign direct investment in China: Institutional change,agglomeration economies,and market access

The spatial inequality of foreign direct investment (FDI) can intensify uneven economic development. As globalization and economic transition proceeds, foreign investors are changing their behaviors in FDI location, based on institutional change and agglomeration effects. In order to reduce the inequality, this research employs spatial statistics and analyses to examine the change in the spatial inequality of FDI among regions and among prefectural cities, and uses regression models and spatial regime analyses to investigate factors influencing the inequality from 1990 to 2010. The spatial diffusion of FDI clusters from the eastern/coastal region to the interior shows the trend of FDI convergence among regions. However, increasing numbers of FDI clusters and hot spots show the increasing divergence among cities within three regions. Agglomeration effects have replaced institutional factors to become one of the most significant factors influencing the FDI inequality among cities. Additionally, special economic zones, coastal open cities, provincial capital cities, and development zones lost their advantages in FDI as more reforms set in. The spatial regime analyses further indicate the significance of market size in FDI in prefecture-level cities and the significance of agglomeration economies in FDI in capitals and municipalities.     

多边形间空间关系查询的异构多核架构并行算法

目前在空间关系查询中常用的Plane Sweep算法是一种串行算法,在处理海量空间数据时效率较低,而已有的并行计算方法对于普通的计算机并不适用。本文针对这个问题,提出了一种多边形间空间关系查询的异构多核架构并行算法,该算法先利用STR树索引过滤掉不相交的多边形,然后将过滤后的多边形数据集合分解为点集合和边集合,并对其构建四叉树索引;在保证数据浮点运算精度符合要求的情况下,利用GPU强大的批量运算能力快速处理边与边的相交情况并据此逐步计算得到环间的拓扑关系,再根据环间拓扑关系计算得到多边形间的维度扩展九交模型(DE-9IM)参数值;根据DE-9IM参数值与空间关系查询条件相比对,输出查询结果。最后通过试验验证了算法的准确性与高效性。     

Causality and dispersion relations in electrical prospecting

The problem of causality in low-frequency electrical prospecting with artificial and natural sources is considered. We present numerical examples of the application of dispersion relations to transfer function spectra used in the induced polarization and controlled-source electromagnetic methods and to the components of telluric, horizontal magnetic, and other magnetotelluric tensors. Approaches to the processing and interpretation of spectra with violated dispersion relations are proposed.     

Theoretical investigation of the effects of consolidation on contaminant transport through clay barriers

Consolidation of clayey contaminant barriers such as landfill liners has been postulated as a cause of early breakthrough of contaminants. In this paper we theoretically investigate this proposition. For this purpose a sophisticated one‐dimensional, large‐deformation model of coupled mechanical consolidation and solute transport is employed. This new model is a generalization of existing coupled consolidation and solute transport models described in the literature. It takes into account both non‐linearities in geometry as well as constitutive relations. The latter relate the compressibility, hydraulic conductivity and coefficient of effective diffusivity to the deformation of the soil. The model is applied to a case study of a clay liner and geomembrane system. Results obtained from numerical solution of the model equations are compared with those from various simplified models, including a ‘diffusion only’ (i.e. a rigid soil) model traditionally used in contaminant barrier design. For barriers incorporating low compressibility soils (as for many well compacted clays), there is little difference between contaminant transit (i.e. breakthrough) times predicted by the two models. However, for contaminant barriers incorporating more compressible soils, consolidation is shown to significantly accelerate transport. These results indicate the potential importance of accounting for the effects of soil consolidation and highlight the limitations of existing models when modelling solute transport through composite barriers utilizing soft soils. Based on these limited results, we suggest a possible way of taking into account soil consolidation using simplified models. Copyright © 2008 John Wiley & Sons, Ltd.