Regional Differentiation and Classification for Carrying Constraints on the Resources and Environment of China

Research on the relationship between national resource constraint-region types and environmental carrying capacity is essential for the continued development of Chinese industrialization and urbanization. Thus, utilizing a series of key indexes including the per-capita potential of available land resources, the per-capita potential of available water resources, the degree of environmental stress, and the degree of ecological restriction, a step-by-step, integrated measuring method is presented here to understand the constrained carrying elements of water and land resources as well as environment and ecology. Spatial differences are analyzed and area types classified at the county level across China. Results reveal that: (1) Almost 90% of China is strongly constrained by both resources and the environment, while nearly 50% of national territory is strongly constrained by two elements, especially in areas of intensive population and industry to the east of the Helan-Longmen Mountain line; (2) Densely populated areas of eastern and central China, as well as on the Tibetan Plateau, are strongly constrained by a shortage of land resources, while North China, the northwest, northeast, the Sichuan basin, and some southern cities are experiencing strong constraints because of water shortages. In contrast, the North China plain, the Yangtze River delta, northern Jiangsu, Sichuan province, Chongqing municipality, Guizhou and Guangxi provinces, the northeast plain, and the northern Loess Plateau are constrained by high levels of environmental stress. Areas of China that are strongly ecologically constrained tend to be concentrated to the southwest of the Tianshan-Dabie Mountain line, as well as in the northeast on the Loess Plateau, in the Alashan of Inner Mongolia, in northeast China, and in the northern Jiangsu coastal area; (3) Constraints on national resources and environmental carrying capacity are diverse and cross-cut China, meanwhile, multi-element spatial distribution does reveal a degree of relative centralization. With the exception of the Tibetan Plateau which is resources-ecological constraint , other areas subject to cross constraints are mainly concentrated to the east of the Helan-Longmen Mountain line.     

The Internet, mobile phone and space-time constraints

While the implications of information and communication technologies (ICTs) for daily travel and activities have been studied extensively, there is only scant attention paid to the relations between ICTs and space-time constraints. This study therefore explores the extent to which the Internet and mobile phone increase the spatial and temporal flexibility of everyday activities through a review of the literature and empirical research with data from Columbus (Ohio, USA) and Utrecht (The Netherlands). The analysis suggests that the implications of the Internet and mobile phone are complex and dependent on the type of activity, persons involved, technologies and socio-physical context in which they are embedded. Various regularities can, however, be detected. For the study participants, the Internet and mobile phone relax temporal constraints to a stronger degree than they enhance spatial flexibility. There are also space-time constraints that seem to persist or have come about because of ICT adoption. Finally, it appears that the Internet and mobile phone at best consolidate differences between men and women in the space-time constraints associated with everyday activities.     

一种顾及空间关系约束的线化简算法

线要素化简在制图表达与综合领域一直是研究的热点和难点之一。然而,经典化简算法多针对单独线要素进行处理,缺乏对该线要素与周边线要素之间整体空间关系的考虑,并且,存在计算结果生硬(D-P算法)、局部极值点缺失,特别是在曲度较大之处出现相交异常(L-O算法)等问题。为此,本文提出一种顾及空间关系约束的线化简算法,建立线要素全局化简方法(LGSM)和矢量位移、面积位移等5类评价指标。采用等高线、河流和道路3类线要素实际数据进行了试验,充分检验了本文算法的优越性,其处理结果符合开方根模型规律,降低了曲线复杂度,在保证全局空间关系不变条件下,不仅更好地保持了曲线整体形状特征,而且光滑美观、精度高。     

空间管治视角下京津冀协同发展类型区划

京津冀协同发展的核心是基于问题导向和底线思维,打破行政区划,在更大区域尺度上优化资源配置,实现区域整体发展目标。因此,从优化空间规划体系的高度,开展京津冀区域协同发展的类型区划和类型区管理,实现分区施策的精细化管治极为重要。本文首先立足于京津冀区域发展差异,利用空间属性双聚类的方法将京津冀划分为中部核心功能引领区、东部沿海重点发展区、南部门户功能拓展区、西部和北部生态涵养保护区等四大区域;然后以区县为最小分析单元,从现状开发强度、用地增量预测和生态保护责任等三大维度构建类型划分指标体系,并利用三维空间坐标划分方法将京津冀划分为五大类型区,即：城镇优化发展区、城镇重点拓展区、现代农业发展区、适度建设发展区和严格生态保护区;最后,在空间管治视角下提出京津冀区域分区管治与区域协同管理的建议。     

基于物方空间几何约束最小二乘匹配的建筑物半自动提取方法

提出了一种从数字航空立体像对半自动提取建筑物的方法。操作员通过人机界面选择房屋的种类并输入初始位置，然后经过边缘检测、直线段提取和据此房屋几何模型的线段自动编组等处理得到各房屋角点的初始位置，最后，为了获得房屋的精确定位和符合物方严格几何约束的结果，基于物方空间几何约束的最小二乘匹配平差模型用于求取房屋直线边缘和物方几何模型的最优匹配，试验表明，该方法能提高建筑物的提取精度并可为半自动建筑物提取提供一个灵活的框架。     

太平洋地区海气系统年代际变率研究的若干进展

系统回顾了近年来太平洋地区海气系统年代变率的研究进展，涉及大气环流，海洋状况及汽气相互作用的年代际变化，以及产生这种年代际变率的主要机制，并简单讨论了目前该领域研究中存在的主要问题及研究前景。     

约束最小二乘问题的几个算法

讨论了具有线性等式与不等式最小二乘问题及等式约束带权最小二乘问题 ,运用矩阵Householder正交分解及有效约束集法等技巧 ,分别给出了几个有效实用的算法 ,最后进行了数值检验。     

一种利用单张影像进行规则物体三维重建的方法

提出了一种以单张影像为基础,基于灭点几何原理、共线条件方程及共面约束条件,进行规则物体三维重建的方法。该方法通过影像中的3条两两垂直的直线,利用灭点几何原理得到了影像的方位角元素;利用解算的角元素及共线方程得到了摄影中心坐标;最后,利用解算的影像外方位元素及共面约束条件得到规则物体的三维几何模型。     

1—3月欧亚大陆热力变化及其与中国降水的关系

利用1979—2011年NCEP/NCAR再分析资料、我国160个站降水和气温资料,分析欧亚大陆热力变化特征,其在冬季和春季的气候变率最明显,且南北区域呈反相差异。在此基础上, 探讨1—3月欧亚大陆热力差异与中国降水异常的关系,欧亚大陆正 (负) 热力差异年,1—3月华南、西南至河套西部地区降水偏多 (少) 明显,后期夏季多雨带位于长江中下游地区 (华南地区)。大气环流异常特征显示:1—3月欧亚大陆南北热力差异与同期北极涛动 (AO)、东亚大槽、东亚高空急流等大尺度大气环流,以及后期东亚高空急流、南亚高压、低层季风风系异常的密切相关是欧亚大陆热力变化与中国降水联系的可能途径。     

Estimating Population Attribute Values in a Table: “Get Me Started in” Iterative Proportional Fitting

Iterative proportional fitting (IPF) is a technique that can be used to adjust a distribution reported in one data set by totals reported in others. IPF is used to revise tables of data where the information is incomplete, inaccurate, outdated, or a sample. Although widely applied, the IPF methodology is rarely presented in a way that is accessible to nonexpert users. This article fills that gap through discussion of how to operationalize the method and argues that IPF is an accessible and transparent tool that can be applied to a range of data situations in population geography and demography. It offers three case study examples where IPF has been applied to geographical data problems; the data and algorithms are made available to users as supplementary material.