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省情综合地图集使用专题地图对省域的资源禀赋和社会发展水平进行全面展示,是一项复杂的知识系统。通过对地图集中大量、复杂、非结构化的内容进行模式化重构,建立地图集的内容图谱,挖掘中国省情综合地图集的内容组织规律。首先,构建图集词汇向量和计算语义相似度,提取图集内容表达的标准主题词;然后,结合图集的“图组→图幅→指标”编排结构,对主题词进行语义层次聚类,构建图集内容表达的树型图谱;在此基础上,挖掘各省综合地图集内容图谱的频繁子图,形成图谱指纹,以此标识出中国省情综合地图集主题表达的共性特征。研究结果表明,中国省情综合地图集的主题内容具有层次化组织特点,可将指纹图谱作为框架,指导省情综合地图集的主题选择和内容组织。借助内容图谱和指纹图谱分析,还可进一步揭示出中国各省综合地图集在内容表达上具有明显的聚类特征和多样性特征。研究结果可为新编省情综合地图集设计提供依据。未来还可进一步探究不同类型地图集的内容图谱构成,丰富地图集设计与编制理论。 相似文献
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区域综合地图集是地图集中涉及学科最多、包含领域最广的地图集,其主题和内容结构设计直接决定了图集的内在特性和系统程度。首先分析了区域综合地图集的主题设计思路,然后从层次性、有序性等方面重点阐述了区域综合地图集的结构体系和主题内容,最后总结了区域综合地图集在编制方面的理论与实践经验。 相似文献
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地图集是地图的一种综合表现形式,其综合各类要素,根据一定的数学法则,采用特定符号与适当形式表达出来。文章对比省市级区域地图集,讨论区级村庄地图集设计的共性与个性。以增城区村庄地图集为例,立足于村庄规划与美丽乡村建设,从科学性、实用性角度展示地图集的内容设计、结构编排与信息表达,以期为今后的村庄地图集编制提供借鉴。 相似文献
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关于区域性综合地图集设计理念的思考 总被引：2，自引：0，他引：2
区域性综合地图集是地图集中涉及学科最多,包含领域最广的地图集。经过地图学界多年的研究与实践,已经形成了一定的模式,其主题与结构已比较程式化。本文力图通过作者本人在实际工作中的体验,就区域性综合地图集设计理念的创新作一探讨。 相似文献
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以《广州城市地图集》及其移动版增强现实(augmented reality,AR)互动电子地图的设计与研发为例,从城市地图集的内容选题、可视化表达和成果应用方面,探索城市地图集对城市文化的挖掘和表达,并介绍了AR技术、图像自动识别技术、矢量瓦片电子地图、HTML5动态网页、全景和三维电子地图在《广州城市地图集》移动版中的创新应用方式,可为其他城市地图集和综合地图集的编制提供借鉴和参考。 相似文献
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在数字制图环境下,尽管区域综合地图集的编制技术手段、制图工艺、产品形式、服务模式等方面都发生了巨大的变革,但地图的内容表达设计仍是图集编制中的核心任务。结合工作实践,对区域综合地图集的地理底图、基础地理信息以及专题信息等的内容表达进行了探讨,进一步阐述了图集实施中空间信息可视化的原则和方法。 相似文献
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《International Journal of Digital Earth》2013,6(1):80-87
Abstract Cultures throughout the world are associating with the rivers. People depend upon the rivers and their tributaries for food, water, transport, and many other aspects of their daily lives. Unfortunately, human beings have not calculated the accurate lengths for the great rivers even today. The lengths of the rivers are very different in popular textbooks, magazines, atlases and encyclopedias, etc. To accurately determine the lengths of the principal rivers of the world, the combination of satellite image analysis and field investigations to the source regions is proposed in this paper. The lengths of the Nile, Amazon, Yangtze, Mississippi, Yellow, Ob, Yenisey, Amur, Congo and Mekong, with lengths over or close to 5000 km, were calculated using the proposed method. The results may represent the most reliable and accurate lengths of the principal rivers of the world that are currently achievable. 相似文献
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软科学这一术语是70年代在国外提出的.然而30多年以来,它在国外不仅未得到普遍的承认,而且对软科学的定义也还未能达成大体上一致的共识.而在改革开放后的中国,出于决策科学化和民主化的需要,经过一些领导人的提倡和支持,特别是通过1986年召开的软科学座谈会及1994年召开的全国软科学工作会议,软科学事业得到了蓬勃的发展.据初步统计,截止1998年底全国共有软科学研究机构1224个,研究人员32655人,初步形成了一支较为强大的研究队伍,并取得了数百项覆盖多个领域的研究成果,为支持各级各类的决策发挥了一定的作用. 相似文献
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Tobias Nilsson Benedikt Soja Kyriakos Balidakis Maria Karbon Robert Heinkelmann Zhiguo Deng Harald Schuh 《Journal of Geodesy》2017,91(7):857-866
The very long baseline interferometry (VLBI) Intensive sessions are typically 1-h and single-baseline VLBI sessions, specifically designed to yield low-latency estimates of UT1-UTC. In this work, we investigate what accuracy is obtained from these sessions and how it can be improved. In particular, we study the modeling of the troposphere in the data analysis. The impact of including external information on the zenith wet delays (ZWD) and tropospheric gradients from GPS or numerical weather prediction models is studied. Additionally, we test estimating tropospheric gradients in the data analysis, which is normally not done. To evaluate the results, we compared the UT1-UTC values from the Intensives to those from simultaneous 24-h VLBI session. Furthermore, we calculated length of day (LOD) estimates using the UT1-UTC values from consecutive Intensives and compared these to the LOD estimated by GPS. We find that there is not much benefit in using external ZWD; however, including external information on the gradients improves the agreement with the reference data. If gradients are estimated in the data analysis, and appropriate constraints are applied, the WRMS difference w.r.t. UT1-UTC from 24-h sessions is reduced by 5% and the WRMS difference w.r.t. the LOD from GPS by up to 12%. The best agreement between Intensives and the reference time series is obtained when using both external gradients from GPS and additionally estimating gradients in the data analysis. 相似文献
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In this letter, we are trying to resolve the electromagnetic problem for the movements of the superconducting particles of the protoplanetary cloud in the magnetic field of Saturn. The force of levitation (Meissner-Ochsenfeld phenomenon) is introduced to the field of planetary science for the first time. It is shown from our theoretical analysis that rings of Saturn might have a superconducting origin, and rings might levitate within magnetic equator plane of the planet. 相似文献
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当目标面与像片平面不平行时,圆形标志的像将为椭圆,椭圆的中心与标志中心的像存在偏差。当标志较大时,此偏差将显著影响求解的精度。揭示了偏差的方向性,导出了求解偏差的方程,给出了偏差的解算步骤 相似文献