带岛区约束数据域的Delaunay三角剖分通用算法研究     

邓曙光  陈明  郑智华  唐敏 《测绘科学》2007,32(5):63-64

文章提出了一种可解决带岛区约束数据域的三角剖分通用算法,通过对岛区制图边界拓扑结构建立与分析,引入双联点和辅助约束边界概念对岛区外部划分子区(抽象出凸或凹多边形),再采用任意多边形内部三角剖分算法,实现了带岛区约束数据域的Delaunay三角剖分并应用于油气勘探设计等领域。  相似文献   

基于传输速度的中国城市节点间互联网信息联系通达性研究   总被引：2，自引：0，他引：2  

路紫  杨东  张秋娈  王文娟 《地理科学》2014,(11):1313-1319

通过对网站信息传输速度数据连续6个月的采集,编制出中国31个城市节点间信息传输速度矩阵。运用因子分析法计算出各城市节点对应的综合得分,并划分出等级,进而对最优等级/最差等级所涉及的城市节点进行频次统计,以分析信息联系通达性的等级特征。通过传输速度的等级划分,揭示高速连接线路和较高速连接线路的空间特征,最后对若干影响因素进行解释。研究发现:城市节点的输出和输入速度不一致,输出最优节点都处于主干网或与北京直接相连,输入最优节点与主干网关系不密切,输出和输入最差节点多处在网络末端;互联网信息联系通达性与传统城市等级间的正向对应关系发生偏转,传统等级靠前的城市节点信息传输通达性较弱;影响信息联系通达性的因素包括网络设置与网络组织、信息化建设与城市等级、网络服务运营商及其互通等,互联网服务商的供给和用户需求的对接有待改善。  相似文献   

图像匹配的物体空间关系推理表达     

李钦  游雄  李科  王玮琦 《测绘学报》2021,50(1):117-131

物体空间关系指的是物体在欧氏空间中的邻近关系,根据图像中包含物体的邻近关系解决图像匹配的问题。本文首先基于对比机制训练物体块特征提取网络,构建物体块深度特征,该特征可以有效匹配不同图像中的相同物体块;其次,基于已有的先验图像数据推理表达图像中物体的空间邻近关系,构建场景物体空间邻近图;进而基于该空间邻近图计算场景图像对的空间邻近度,完成图像空间关系匹配。试验表明不匹配图像间的空间邻近度一般为0,而匹配图像间的空间邻近度一般大于0,本文空间关系匹配涉及多个物体间的相互关系,具有更强的稳健性,其匹配效果明显优于对比试验中的其他方法,可以高效稳定地完成图像匹配任务。  相似文献   

丝绸之路经济带节点城市人文驱动因素对环境的影响   总被引：1，自引：0，他引：1  

虞文宝  宋晓谕  简富缋 《冰川冻土》2017,39(1):200-206

“一带一路”上升为国家战略,推进丝绸之路经济带建设使中国西北地区由过去发展的腹地转变为开放的前沿。通过引入STIRPAT模型,研究分析了丝绸之路经济带节点城市人文驱动因素对环境的影响,设定了三种情景分析节点城市未来低碳发展情况。结果表明：人文驱动因素对碳排放的影响程度较大,模型拟合优度达到95.2%,能源消耗强度（T）、富裕程度（A）和人口数量（P）的弹性系数分别为0.511、0.285和0.222,基准情景下二氧化碳排放总量呈现稳步上升态势,政策情景和低碳情景下碳排放存在“拐点”,预计碳排放峰值将在2025-2033年间出现,低碳情景峰值比政策情景提前8 a到达,峰值总量减少40.79×10⁴ t。最后针对分析结果就丝绸之路经济带节点城市人文驱动因素对环境的影响提出了相关建议,即控制人口数量、优化产业结构、强化污染治理。  相似文献   

Location characteristics and differentiation mechanism of logistics nodes and logistics enterprises based on points of interest (POI): A case study of Beijing   总被引：1，自引：0，他引：1  

Guoqi Li  Fengjun Jin  Yu Chen  Jinjuan Jiao  Sijing Liu 《地理学报(英文版)》2017,27(7):879-896

The logistics nodes and logistics enterprises are the core carriers and organizational subjects of the logistics space, and their location characteristics and differentiation strategies are of key importance to optimizing urban logistics spatial patterns and ensuring reasonable resource allocation. Based on Tencent Online Maps Platform from December 2014, 4396 logistics points of interest (POI) were collected in Beijing, China. By the methods of industrial concentration evaluation and kernel density analysis, the spatial distribution pattern of logistics in Beijing are explored, the interaction mechanism among the type difference, supply-demand side factors and location choice behavior are clarified, and the internal mechanism of spatial differentiation under the combined influence of transportation, land rent and assets are revealed. The following conclusions are drawn in the paper. (1) Logistics enterprises and logistics nodes exhibit the characteristic of both co-agglomeration and spatial separation in location, and logistics activities display the spatial pattern of "marginal area of downtown area, suburbs and exurban area", which have a weak coupling degree with logistics employment space. (2) The public logistics space, namely, logistics parks and logistics centers, is produced under the guidance of the government, and the terminal logistics space consisting of logistics distribution centers serving for the specific industries and terminal users is dominated by enterprises. The locational differentiation between the two modes of logistics space is significant. (3) In the formation of the logistics spatial location, the government can change the traffic condition by re-planning the transport routes and freight station locations, and control the land rent and availability of different areas by increasing or decreasing the land use of logistics, to impact the enterprise behavior and form different types of logistics space and function differentiation. In comparison, logistics enterprises meet the diverse demands of service objects through differentiation of asset allocation to promote the specialization of division and form the object differentiation of logistics space.  相似文献   

广东省自然保护区生态网络评价及其生态修复建议     

袁少雄  宫清华  陈军  王均  黄光庆  刘峰 《热带地理》2021,41(2):431-440

以广东省自然保护区作为生态源地,利用最小累积阻力模型,分析潜在生态廊道,通过增加河流与高速公路廊道形成综合生态网络(CEN),并利用α指数、β指数、γ指数和成本比对CEN进行评价,结果显示:由潜在生态廊道构成的基础生态网络(BEN),α、β、γ指数分别为0.54、2.02和0.70,说明其能使广东省自然保护区结构复杂化...  相似文献