共查询到20条相似文献，搜索用时 31 毫秒
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Schematic maps have been popularly used for the representation of metro (or underground) lines and nowadays have also been used for the representation of other network maps. This paper presents a strategy for automated generation of schematic network maps for different display sizes, based on a redistribution of line density. This strategy consists of three steps: (a) estimation of spatial density of the network maps, (b) automated redistribution of line density in order to improve map clarity, for different display sizes, and (c) automated generation of schematic representations. An experimental evaluation has been carried out by using two sets of real-life network data. The results indicate that this strategy is able to generate schematic maps with much improved clarity for different display sizes and well-preserved map recognition. 相似文献
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当前示意性地图表达主要针对公共交通网络,缺乏对道路地图示意性表达可用性评估研究。本文选取景区和街道两个典型道路场景,采用最新的自动示意化方法生成示意地图,以主观问卷调查结合客观眼动试验的方式,评估道路地图示意性表达的可用性。试验结果表明:①示意性表达能够提升道路地图的简化度、清晰度及用户满意度,尤其对于原始道路形状较为复杂的情况;②示意地图中路径形状简化会造成不同路径感知长度差异的改变,从而影响到人们路径抉择行为;③对于路径示意性结果增加了道路网密集程度的情况,会降低示意地图认知效率。本文研究成果有助于道路地图自动示意性表达规则完善和方法优化,能够进一步提升地图示意性表达的实用性。 相似文献
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移动电子地图中伪3D可视化设计 总被引：1，自引：0，他引：1
定义了移动电子地图中伪3D可视化概念,提出伪3D可视化模型,并设计了快速的三维投影变换算法。进行了移动电子地图的伪3D可视化实验设计,并给出了可视化性能测试结果。 相似文献
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Zhilin Li 《The Cartographic journal》2013,50(4):356-360
Usually, a street map contains various types of detailed information and appears to be crowded. As a result, to many users, a street map looks complicated and is not easy to read and follow. In fact, to a certain degree, too much detail makes the map uninformative and noisy. The London tube map, called a schematic or topological map in some literature, has often been cited as an excellent example of a simplified map. Algorithms have been developed by researchers to automate the generation of schematic maps for road networks. However, it is found that there is still a lack of defined general principles and here four general principles have been formulated for schematisation – the Principle of the Preservation of the Topological Relationship; the Principle of the Preservation of the Main Structure of the Line Network; the Principle of Relativity in Position; and the Principle of Relativity in Length. The first two are the principles of preservation: these two should never be violated. The last two are principles of relativity: it is very desirable to keep these two intact unless there is an absolute need to violate them. 相似文献
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《制图学和地理信息科学》2013,40(4):285-301
How to effectively represent spatial information on handheld mobile devices is a key question, given the increasing use of personal digital assistants (PDAs) and cell phones concurrent with the development of location-based services. The mobile use of digital maps on small displays presents new capabilities and challenges that differ from using paper maps in a mobile setting or viewing digital maps on a desktop computer. This research addresses these issues through a study that evaluated maps on a mobile device used for a field-based navigation task. Map representations at two levels of generalization were compared by analyzing subject performance in a pedestrian route-following task, in which a handheld computer was used as a navigation aid. Subject time and accuracy as well as interaction with the mobile device during the task were measured. The results carry implications for map design for small, mobile displays and identify factors that affect the use of maps while moving. Maps are and will increasingly be used on small displays in mobile contexts for a variety of purposes and in many different environments. The requirements and preferences of mobile users, as well as how these maps are used in different contexts, must be understood in order to inform more effective designs. 相似文献
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从整体到局部相互协调是示意性网络地图的关键所在,已有方法多是单纯地将线段作为示意基本单元,当空间要素分布不均衡时,容易产生示意结果全局表达不一致以及局部要素过于紧凑而变形的现象。考虑网络连通与网络闭合这两个性质,提出了一种化简分割生成方法,核心思想是根据连通化简网络,进而依据闭合构建网眼与线段两种基本示意单元。首先,对网络节点化简以及方向、长度调整,形成整体一致的化简网络;其次,将化简网络分割为网眼集合与线段集合;第三,建立从网眼至线段的示意化过程,通过网眼局部控制以避免要素过于紧凑。实验讨论了本文方法在不同示意约束规则之下的表现效果,与经典迭代寻优方法的对比分析表明,在网络整体形态保持与局部要素布置方面具有一定的优势。 相似文献
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空间数据的压缩对于空间数据无线移动网络以及提高整个移动GIS系统的效率来说是一项很重要的工作。文章针对移动GIS系统中的矢量数据压缩问题进行了总结与综述。首先分析了矢量地图数据压缩的原因并给出了其定义;然后对传统的矢量数据压缩方法作了简单的介绍;最后对经典的Douglas—Peucker方法的改进方法,小波技术压缩方法和第二代小波压缩方法进行了详细的分析。 相似文献
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Paper maps and mobile electronic devices have complementary strengths and shortcomings in outdoor use. In many scenarios, like small craft sailing or cross-country trekking, a complete replacement of maps is neither useful nor desirable. Paper maps are fail-safe, relatively cheap, offer superior resolution and provide large scale overview. In uses like open-water sailing it is therefore mandatory to carry adequate maps/charts. GPS based mobile devices, on the other hand, offer useful features like automatic positioning and plotting, real-time information update and dynamic adaptation to user requirements. While paper maps are now commonly used in combination with mobile GPS devices, there is no meaningful integration between the two, and the combined use leads to a number of interaction problems and potential safety issues. In this paper we explore the design space of augmented paper maps in which maps are augmented with additional functionality through a mobile device to achieve a meaningful integration between device and map that combines their respective strengths. 相似文献
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以城市轨道交通示意图为对象,利用AHP方法构建了一个注记质量评价模型。在考虑可辨阈限、注记-要素压盖度、优先级、注记-要素关联性4个独立指标的基础上,补充了单位面积注记量和偏移量两个修正指标。选取上海、伦敦、莫斯科、米兰和圣保罗5个城市的轨道交通示意图进行实例验证,结果显示两个修正指标的提出具有合理性,可为注记配置的自动化提供基本参考。 相似文献
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采用形式语言的方法,研究了移动地图制图的句法模型。剖析了移动地图制图的过程,将句法模型定位在制图的逻辑演算层面;结合地图表达的层次性和递归性特征,将移动地图制图的句法结构抽象为"制图词汇+句法规则"的最简形式。在制图词汇方面,建立了制图词汇的分类体系,并重点对空间关系谓词系统进行了建模;在句法规则方面,描述了句法操作规则和不同层次的句法单位描述规则。探讨了句法模型的编译流程和关键技术,并通过试验对移动地图制图句法模型的可行性进行了验证。句法模型的本质是一种使用有限规则和词汇动态生成不同地图表达形式的形式语言语法,可作为一种高阶的人机交互制图接口。 相似文献
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Terrestrial mobile laser scanning systems provide rapid and cost effective 3D point cloud data which can be used for extracting features such as the road edge along a route corridor. This information can assist road authorities in carrying out safety risk assessment studies along road networks. The knowledge of the road edge is also a prerequisite for the automatic estimation of most other road features. In this paper, we present an algorithm which has been developed for extracting left and right road edges from terrestrial mobile LiDAR data. The algorithm is based on a novel combination of two modified versions of the parametric active contour or snake model. The parameters involved in the algorithm are selected empirically and are fixed for all the road sections. We have developed a novel way of initialising the snake model based on the navigation information obtained from the mobile mapping vehicle. We tested our algorithm on different types of road sections representing rural, urban and national primary road sections. The successful extraction of road edges from these multiple road section environments validates our algorithm. These findings and knowledge provide valuable insights as well as a prototype road edge extraction tool-set, for both national road authorities and survey companies. 相似文献
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地图所要表达的空间结构通常通过空间关系来建构和描述,包括距离关系、方向关系和拓扑关系。本文基于空间关系认知,从定名量表、顺序量表、间隔量表、比率量表4个量表分析了传统地图与新模式地图的空间关系分辨率的变化过程,并以路网架构图为例,对比了传统地图与新模式地图的认知效果,提出在制图中要重视认知效率和表现对象的细节程度。 相似文献
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本文概述了神经网络计算机的基本特点、神经网络的形式化描述、目前国际上神经网络计算机的现况以及在遥感图像处理中应用的潜力和展望。 相似文献
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CHRISTOPHER J BROOKES 《Transactions in GIS》1997,2(3):201-212
Locating optimal sites on raster suitability maps is a complex problem when the size of the sites is larger than the cell size. There are a number of techniques for generating suitability maps, but these maps are not solutions to the site location problem. Feasible solutions are clusters of contiguous cells which meet spatial criteria concerning the size and shape of the clusters. Locaring optimal sites involves a trade-off between the intrinsic suitability of individual cells and the spatial configuration of cells. This paper describes a genetic algorithm which searches for optimal clusters and thereby locates optimal sites. The genetic algorithm uses a parameterized regiongrowing program to translate numeric strings into regions on a raster and employs raster GIS functions to evaluate utility scores. In a range of simulated problems, comparisons with an exhaustive search show that the genetic algorithm is efficient and robust. The results indicate that the genetic algorithm can find good solutions to real problems when exhaustive search methods are impractical. 相似文献
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Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a concrete experiment while maintaining topological consistency of the road network between the original and the schematic map. 相似文献