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由于地形图与GIS数据所依据的数据模型的差异,基于地形图建立的基础地理数据库系统往往不能同时满足地形图和GIS数据的服务要求。另外,直接面向图层的数据管理模式,割裂了地理要素之间的自然联系,给数据的管理应用带来了不便。针对以上问题,本文提出了面向对象的基础数据库系统的实现思路,阐述了相关设计及实际应用。 相似文献
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摘 要:建筑信息匮乏、缺乏图纸是村落建筑群火灾防控面临的首要问题。针对传统的现场测绘工作量大、费用高、获取数据信息不精确等问题,在现场勘察获取典型单体建筑详细建模数据的基础上,采用无人机倾斜摄影技术获取村落建筑群地理信息数据,并建立村落建筑群火灾蔓延分析模型。进一步采用简化分析方法确定建筑群不同建筑起火后的火灾蔓延情况及火灾蔓延损失。最后以云南省某村落为研究对象,建立了该村落的火灾蔓延模型并分析了火灾蔓延风险。结果表明:该方法能有效获取村落建筑群火灾蔓延模型的建模数据,并为后续的火灾蔓延风险分析提供数据支持。 相似文献
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文中介绍了机载毫米波InSAR地形测绘的原理与方法,并通过试验研究,分析了机载毫米波InSAR技术测制的3D(DEM、DOM、DLG)成果的平面精度和高程精度。讨论了影响DEM高程精度和DLG平面精度的因素。试验表明采用我国自主研发的机载毫米波InSAR系统测制的3D成果,满足1∶5000国家规范的精度要求。 相似文献
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Distributed Hash Tables (DHTs) are scalable, self‐organizing, and adaptive to underlying topology changes, thus being a promising infrastructure for hosting large‐scale distributed applications. The ever‐wider use of DHT infrastructures has found more and more applications that require support for range queries. Recently, a number of DHT‐based range query schemes have been proposed. However, most of them suffer from high query delay or imbalanced load distribution. To address these problems, in this paper we first present an efficient indexing structure called Balanced Kautz (BK) tree that uniformly maps the m‐dimensional data space onto DHT nodes, and then propose a BK tree‐based range query scheme called ERQ that processes range queries in a parallel fashion and guarantees to return the results in a bounded delay. In a DHT with N nodes, ERQ can answer any range of query in less than rmlog N(2loglog N + 1) hops in a load‐balanced manner, irrespective of the queried range, the whole space size, or the number of queried attributes. The effectiveness of our proposals is demonstrated through experiments. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Takashi Narihiro Shinichi Kaiya Hiroyuki Futamata Akira Hiraishi 《Journal of Bioscience and Bioengineering》2010,109(3):249-256
A semi-aerobic, mesophilic, fed-batch composting (FBC) reactor loaded with household garbage was used to remove polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs). The reactor was packed with woodchips as the solid matrix and PCDD/F-contaminated soil or flyash and then operated at a waste-loading rate of 0.5 kg (wet wt) day- 1. All congeners of PCDD/Fs (initial concentration, 200–830 pmol g- 1 [dry wt]) were totally reduced during the over period of operation, with a half reduction time of 4 months. Direct cell counting and respiratory quinone profiling showed that the reactors at the fully acclimated stage harbored a high population density of bacteria (1011 g- 1 [dry wt]) with members of the Actinobacteria predominating. Real-time quantitative PCR showed that the population of “Dehalococcoides” and its phylogenetic relatives of Chloroflexi as the possible dechlorinators varied between at the order of 107 to 108 g- 1 (dry wt). A “Dehalococcoides”-containing dechlorinating culture from the soil-treating reactor was successfully enriched with a model PCDD/F compound, fthalide. 16S rRNA gene-targeted PCR-denaturated gradient gel electrophoresis and clone library analyses showed that this culture comprised at least three major phylogenetic groups of bacteria, Acidaminobacter, “Dehalococcoides,” and Rhizobium. These results suggest that the semi-aerobic FBC process is applicable for the bioremediation of PCDD/Fs and possibly other haloorganic compounds with the biostimulation of “Dehalococcoides” and its relatives as the potent dechlorinators. 相似文献
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机载LiDAR是基础地理信息采集、更新的新型航测技术。本文采用机载LiDAR航测技术测制了从化市区域1 985 km2数字高程模型、数字正射影像、地形数据以及三维地形模型,基于EPS 2008开发了机载LiDAR测图系统,其创新点在于等高线生成、投影差改正,无立体像对的地理要素采集等方面。本文的技术方案作业效率高,实现了当年航摄当年生产,提供的测绘产品丰富且满足质量要求。 相似文献
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通过对Geoway DPS采编一体化数字摄影测量软件在广西1∶10000 DLG(全要素及核心要素)生产工作中的实践应用,对数据采集(更新)的生产技术、生产工艺等技术问题提出见解和实施方案,为保证广西1∶10000 DLG生产的顺利实施提供有效的技术手段和建设性意见。 相似文献