Spatial Object Aggregation Based on Data Structure,Local Triangulation and Hierarchical Analyzing Method     

LIUYaolin  MartienMolenaar 《地球空间信息科学学报》2002,5(1):44-54

This paper focuses on the methods and process of spatial aggregation based on semantic and geometric characteristics of spatial objects and relations among the objects with the help of spatial data structure (Formal Data Structure),the Local Constrained Delaunay Triangulations and semantic hierarchy.The adjacent relation among connected objects and unconnected objects has been studied through constrained triangle as elementary processing unit in aggregation operation.The hierarchical semantic analytical matrix is given for analyzing the similarity between objects types and between objects.Several different cases of aggregation have been presented in this paper.  相似文献   

Multi—scale Representation of Building Feature in Urban GIS     

AITinghua  WANGHong 《地球空间信息科学学报》2002,5(2):37-44

This paper aims at multiscale representation of urban GIS,presenting a model to dynamically generalize the building on the basis of Delaunay triangulation model.Considering the constraints of position accuracy,statistical area balance and orthogonal characteristics in building cluster generalization,this paper gives a progressive algorithm of building cluster aggregation,including conflict detection (where),object(who) displacement,and geometrical combination operation(how).The algorithm has been realized in an interactive generalization system and some experiment illustrations are provided.  相似文献   

基于主成分变换模型的DEM格网聚合及其误差分析     

黄泽纯  张倩宁  徐柱  洪安东  张瑞芳 《测绘学报》2017,46(3):389-397

利用主成分分析揭示变量之间关系的特性,进而提出一种既能保证较高精度又能较好地保持地形形态特征的DEM格网聚合方法。首先根据主成分变换模型推导DEM格网聚合数学公式,构建主成分聚合模型;然后以30m分辨率DEM转换为90m分辨率DEM为例,根据格网点属性间的权重关系聚合重构DEM。在此基础上,以均值聚合和双线性重采样聚合方法为比较对象,从聚合前后的检查点高程偏差的统计描述、空间分布与自相关性、地形形态保持程度方面分析3种聚合策略下重构DEM的误差特性。最后运用描述统计、半变异分析和等高线套合方法,定量评价主成分聚合重构DEM的质量效果。试验分析结果表明,同均值聚合和重采样聚合相比较,该方法重构的DEM既能保持较高精度,又能很好地保持地形形态特征。  相似文献   

基于SMCS的多源空间数据集成应用   总被引：1，自引：0，他引：1  

付迎春  袁修孝 《测绘科学》2008,33(4)

为解决多源空间数据特别是不同参考基准数据实时集成困难的问题,通过分析空间元数据间关系,定义并利用元数据知识来实现空间元数据的动态聚合和目录服务SMCS的构建。实验结果表明顾及空间关系的SMCS提高了对空间信息的动态获取、处理和发布的能力和效率,为网格环境下多源数据的高效集成应用服务提供技术支持。  相似文献   

大连红黏土形成期研究     

林世文  兰荣旺 《岩土工程技术》2008,22(2):105-108,F0003

从大连红黏土被第四系松散层所覆盖的现象出发,分析了大连地区沿海岸附近冰碛残丘的特征与形成过程。论证了大连地区陆地和海湾的红黏土都具有聚合沉积的特征,并且确定了大连红黏土形成期是在第四系冰川期之前。此外论证了大连红黏土是大连地区古地理古气候的标志性地层之一。  相似文献   

河南省高速交通网通达性时空特征及演化规律     

张开广  巴明廷  孟红玲  孙艳敏 《测绘科学》2017,42(6)

针对河南省高速公路建设对城市通达性影响问题,该文通过定义时间阈值,设计了基于人口加权时间距离倒数的通达性指数,在4个时间断面上,研究河南省高速交通网络中通达性时空特征及演化规律,时间距离倒数有效减小了多路径时间距离对分析结果的数字影响。结果表明,随着河南高速交通网络的拓展,城市通达性水平得到了显著的提升,空间收敛显著,边缘城市的提升始终高于中心区域城市;高速公路通车里程增长率与通达性水平的改善存在非协调现象;城市通达性的空间聚集现象震荡走弱,聚集区域减少;城市通达性空间分布变化规律和城市化人口变化规律逐渐趋于协调。  相似文献   

Transparent exopolymer particles (TEP) in aquatic environments   总被引：7，自引：0，他引：7  

U. Passow   《Progress in Oceanography》2002,55(3-4)

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Trends in cpue and related changes in spatial distribution of demersal fish species in the Kattegat and Skagerrak, eastern North Sea, between 1981 and 2003     

Casini  Michele; Cardinale  Massimiliano; Hjelm  Joakim; Vitale  Francesca 《ICES Journal of Marine Science》2005,62(4):671-682

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Relationship Between the Spatiotemporal Distribution of Dominant Small Pelagic Fishes and Environmental Factors in Mauritanian Waters     

Ebango Ngando  Narcisse  Song  Liming  Cui  Hongxing  Xu  Shuangquan 《中国海洋大学学报(英文版)》2020,19(2):393-408

The relationship between the spatiotemporal distribution of three dominant small pelagic fishes,including chub mackerel(Scomber japonicus),horse mackerel(Trachurus trecae)and round sardinella(Sardinella aurita),and the environmental factors in Mauritanian waters were analyzed by using 4 years of logbook data of commercial purse seine fisheries to improve the efficiency of fishery and management of sustainable exploitation.A Tweedie-generalized additive model(GAM)of 8-day average catches and the monthly geostatistical analysis of daily catches were used in this study to analyze the influence of environmental factors on catch per unit of effort(CPUEs)and to map the spatial distribution of three mixed dominant small pelagic fishes,respectively.A 10'×10' grid was used,and environmental factors were processed from remote sensing,including 8-day average sea surface temperature(SST),the nearest distance between SST fronts and CPUE position(Df),chlorophyll-a(Chl-a)concentration,salinity,and eddy kinetic energy.Results showed that 1)the distribution of three dominant small pelagic fishes might be related to the intensity of upwelling in Mauritanian waters;2)oceanic fronts might play a key role in the ecology of chub mackerel,horse mackerel,and round sardinella;3)Chl-a concentration might be associated with the feeding grounds of chub mackerel;4)the target species distribution appeared sensitive to gradient changes in the amount of salinity;5)three zones(northern,central,and southern)with variable abundances were delineated;and 6)a high concentration of the center of gravity in the central zone might be related to the strong upwelling of nutrient-rich waters.This study can provide new insights to enhance the fishery efficiency and sustainable exploitation management of purse seiners in certain area off Mauritania.  相似文献   

交通投资、经济空间集聚与多样化路径——空间面板回归与结构方程模型视角   总被引：2，自引：2，他引：0  

林雄斌  杨家文  陶卓霖  宋金平  任颋 《地理学报》2018,73(10):1970-1984

交通投资作为经济增长的加速器备受空间规划与发展政策的重视,其对经济增长的多样化影响一直是研究热点。然而,交通投资对经济的影响机理及路径仍存在争议,且较缺乏地理差异和空间关联的视角。为了全面理解交通投资对经济的空间集聚效应与多样化路径,首先基于1997-2015年中国交通投资与经济增长的省际数据,采用空间面板回归（Spatial Panel Regression）分析考虑空间关联的交通投资的经济影响,随后采用结构方程模型理解交通投资对经济增长的多样化路径。结果表明：① 无论是混合最小二乘回归（Pooled OLS）、固定效应面板模型还是空间面板回归,都显示了交通投资对经济增长的显著作用。空间面板回归结果指出交通投资有利于经济活动空间集聚,但考虑空间自相关影响后,对经济增长作用呈现降低;② 交通投资的经济影响具有地理差异与时滞效应,其对东部地区的经济作用明显高于中西部地区,且有利于空间集聚;随着时间的推移,交通投资的经济效应逐渐增强;当前投资和前期投资对经济增长均有促进作用,但前期投资效果更显著,并驱动经济活动的空间分散;③ 在影响路径上,交通投资对经济的直接效应低于间接效应,多样化影响路径主要通过增加关联产业投资、促进就业增长、推进城镇化等方式产生。  相似文献