基于规则数据驱动的专题制图技术及其应用研究

地图制图自动化是地图学的重要目标之一,也是当前研究的热点问题之一,对地球空间信息科学的发展具有十分重要的意义。通过采用Representation技术,以昆明市入滇河道(管线)专题地图制图项目为例,研究探讨基于规则化数据驱动的计算机地图制图表达,部分解决了传统上必须通过大量人工编辑才能够完成的制图任务,特别是实现了传统上需要以破坏数据的GIS属性为代价才能够实现的地图制图效果,结果表明:基于规则驱动的计算机地图制图表达技术能够兼顾GIS和地图制图对数据的不同要求,可快速完成地图制作,并达到传统地图制图效果,节省大量的人力物力,具有广阔的推广和工程应用价值。     

基于PCI_GXL系统解决弱交会条件下卫星影像纠正方法的研究

介绍了在弱交会条件下利用PCI_GXL系统实现稀少控制点区域卫星影像的几何纠正方法。阐述了基本操作流程以及每个步骤的注意事项,突显出PCI_GXL系统的高效等特点,并对纠正后影像做出精度检测并给出分析评价。对多源数据的处理能力给影像数据生产带来了新的动力。     

Coverage optimization in continuous space facility siting

Facility placement and associated service coverage are major concerns in urban and regional planning. In this paper an approach is detailed for the problem of covering spatial demand for service, where potential facilities are located in the continuous plane. It is shown that weighted demand, represented as points, lines or polygons, can be optimally served by a finite number of potential facility locations, called the polygon intersection point set (PIPS). The developed approach is an extension of a point‐based abstraction of demand to more general representations (e.g. points, lines or polygons). An empirical analysis of warning siren siting in Ohio is carried out, highlighting the applicability of this approach.     

多尺度表达的地图设计模型

计算机技术引入地图学之后,引起地图制作与生产方式的极大变革。地图设计作为地图制作的核心,其内涵也发生了重要变化。以电子地图的多尺度表达为目标,探讨了地图设计在时空尺度上的扩展,提出了多尺度地图设计模型。为地图设计知识的抽象化、可视化以及设计知识向普通大众的传播提供了可借鉴的样本。     

Scale-Dependent Representations of Relief Based on Wavelet Analysis

Automatic generalization of geographic information is the core of multi-scale representation of spatial data,but the scale-depentation of spatial data but the scale-dependent generalization methods are far from abundant because of its extreme complicacy.This paperputs forward a new consistency model about scale-dependent representations of relief based on waveley analysis,and discusses the thresholds in the model so as to acquire the continual representations of relief with different details between scales.The model not only meets the need of automatic generalization but also is scale-dependent completely.Some practical examples are given.     

From 2D and 3D GIS for CyberCity

In order to understand the 3D landscape with many high buildings in a city, the 2D GIS has to be extended to 3D GIS. The further development of CyberCity has to include various applications of 3D scenes from the outdoor scenes to the indoor ones. In thispaper, some key techniques, such as data management method and dynamicalvisualization method for the outdoor and the indoor scenes, are discussed. The indoor scene is compared with the outdoor one. The idea of integratedrepresentation of the outdoor and the indoor scenes in CyberCity GIS is discussed. Funded by the open research fund program of LIESMARS (No. 010302).     

三维电阻率正演计算中的Lanczos迭代算法

在三维电阻率的正反演计算中,快速、准确的正演计算是反演的关键。而正演计算往往涉及到求解大型线性方程组Ax=b的问题,通过Lanczos迭代构造出对称三对角阵方程组,并采用正交分解法进行求解,与传统算法相比,此算法占用内存少、收敛速度快、且稳定;针对大型稀疏矩阵的特点,采用简单地记录矩阵的非零元素值及其所在行、列值的方法,来存储大型稀疏矩阵,可大大节省机器内存,提高运算速度。通过理论分析和点电源三维地电场计算实例,阐述该法是地电三维正演计算的有效方法。     

The Effects of Building Representation and Clustering in Large-Eddy Simulations of Flows in Urban Canopies

We perform large-eddy simulations of neutral atmospheric boundary-layer flow over a cluster of buildings surrounded by relatively flat terrain. The first investigated question is the effect of the level of building detail that can be included in the numerical model, a topic not yet addressed by any previous study. The simplest representation is found to give similar results to more refined representations for the mean flow, but not for turbulence. The wind direction on the other hand is found to be important for both mean and turbulent parameters. As many suburban areas are characterised by the clustering of buildings and homes into small areas separated by surfaces of lower roughness, we look at the adjustment of the atmospheric surface layer as it flows from the smoother terrain to the built-up area. This transition has unexpected impacts on the flow; mainly, a zone of global backscatter (energy transfer from the turbulent eddies to the mean flow) is found at the upstream edge of the built-up area.     

社会文化地理知识生产的表征与非表征维度

采用文献归纳和理论思辨法,对社会文化地理知识生产的表征和非表征表达、关系转换及权力政治等内容进行了系统分析。研究认为,表征的本质是作为替代品指代实物符号化的实践,非表征是动态性隐蔽对象显性化的实践。表征与非表征是社会文化地理知识生产的重要维度,两者具有同构性和互补性;出于差异化的逻辑抽象方式,两者又存在较大的表达区分。表征主要是对特殊意义"知识节点"的关注,具有共享性、社会性、说明性和稳定性;非表征主要是对非稳定性流动知识、活力性知识和关联性知识的关注,具有经验性和情境性、具身性和体验性、结构性和交互性;表征与非表征不仅具有内在关联性,也存在转换的必要性,这是人们积极应对社会文化地理知识认识论危机的一种可能方案,也是人们更加精确认识地理知识生产的前提和基础;随着后现代地理学语境的兴起,以及人们对话语、身份等要素的关注,社会文化地理知识生产的表征与非表征方式受到了权力政治因素的影响,这使表征和非表征实践具有了表达协商的意蕴,这一研究发现将创新并拓展对表征和非表征的传统理解。未来研究应多聚焦在表征和非表征的内涵解读、内容和方法呈现层面,这既有利于丰富社会文化地理知识生产的表达方式,也有利于...     

基于网络模型的等高线群拓扑关系表示

等高线群拓扑关系的提取和表示是基于等高线的空间推理和地形特征挖掘的关键。在顾及地形特征的基础上,本文提出了一种拓扑关系网络来组织地理目标之间的拓扑关系,并进而提出分区二叉树、增量等高线树、等高线拓扑关系网三种拓扑关系网络来组织含未封闭等高线的复杂等高线群的拓扑关系,从而从根本上解决了等高线群的侧向不连续性,使基于等高线的空间推理更加简便和准确。