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A Space-Time GIS Approach to Exploring Large Individual-based Spatiotemporal Datasets 总被引:3,自引:0,他引:3
The increasing number of large individual-based spatiotemporal datasets in various research fields has challenged the GIS community to develop analysis tools that can efficiently help researchers explore the datasets in order to uncover useful information. Rooted in Hägerstrand's time geography, this study presents a generalized space-time path (GSTP) approach to facilitating visualization and exploration of spatiotemporal changes among individuals in a large dataset. The fundamental idea of this approach is to derive a small number of representative space-time paths (i.e. GSTPs) from the raw dataset by identifying spatial cluster centers of observed individuals at different time periods and connecting them according to their temporal sequence. A space-time GIS environment is developed to implement the GSTP concept. Different methods of handling temporal data aggregation and the creation of GSTPs are discussed in this article. Using a large individual-based migration history dataset, this study successfully develops an operational space-time GIS prototype in ESRI's ArcScene and ArcMap to provide a proof-of-concept study of this approach. This space-time GIS system demonstrates that the proposed GSTP approach can provide a useful exploratory analysis and geovisualization environment to help researchers effectively search for hidden patterns and trends in such datasets. 相似文献
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《International Journal of Digital Earth》2013,6(1):28-50
Abstract With the proposition of the Digital Earth (DE) concept, Virtual Geographic Information System (VGIS) has started to play the role of a Digital Earth prototype system. Many core problems involved in VGIS, such as out-of-core management and interactive rendering of very large scale terrain and image data, have been well studied in the past decades. However, the jitter problem, a common problem in VGIS that often causes annoying visual artefacts and deteriorates the output image quality, draws little attention. In this paper, after an intensive analysis of the jitter problem, a comprehensive framework is proposed to address such a problem while accounting for the characteristics of different data types in VGIS, such as terrain or ocean mesh data, vector data and 3-D model data. Specifically, this framework provides an improved dynamic local coordinate system (DLCS) method for terrain or ocean mesh data. For vector data, the framework provides a simple and effective multiple local coordinate systems (MLCS) method. The framework provides a MLCS method for 3-D model data making full use of the existing local coordinate system of the model. The advantages of the proposed methods over current approaches are analysed and highlighted through case studies involving large GIS datasets. 相似文献
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地质领域数据量大,且种类多样。实现高效的多源异构地质数据的融合与挖掘,是研究地质作用机理,展开地质考察研究的重要手段。然而目前普遍存在着数据条块分割,格式各异,难以实现有效的共享与互操作。为此,本文提出了一种基于Hadoop的地质大数据融合与挖掘技术框架,该框架包括统一的地质大数据采集与预处理方法,基于元数据索引的存储与管理平台,基于Map/Reduce的地质大数据并行化计算模式与系统,面向可重用的地质大数据挖掘服务,以及支持在线三维展示的地质大数据分析结果可视化系统。该框架具有良好的实用性与可扩展性。本文在5个节点的测试系统上实现了多元素关联性分析,并取得了相对应单台机器3部的加速可比性。 相似文献
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鲁英姿 《测绘与空间地理信息》2011,(6):140-142
数字测图日益成为GIS数据的重要来源,但是由于受到传统测图要求的影响,使得数字测图不能很好地满足GIS的要求。从介绍数字测图入手,通过分析数字测图的作业方式、绘制思想等方面的问题,并对常用的数字测图软件和GIS软件进行对比,指出两者存在的冲突。通过分析数字测图与GIS数据在各个方面的差异,提出GIS数据扩展模型的概念,... 相似文献
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地理信息服务质量(QoGIS):概念和研究框架 总被引:2,自引:0,他引:2
在探讨地理数据特点的基础上,提出了地理信息服务质量(QoGIS)的概念和研究框架,设计了一个体现地理信息服务质量的原型系统架构。 相似文献
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A Space‐Time Raster GIS Data Model for Spatiotemporal Analysis of Vegetation Responses to a Freeze Event
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Many past space‐time GIS data models viewed the world mainly from a spatial perspective. They attached a time stamp to each state of an entity or the entire area of study. This approach is less efficient for certain spatio‐temporal analyses that focus on how locations change over time, which require researchers to view each location from a temporal perspective. In this article, we present a data model to organize multi‐temporal remote sensing datasets and track their changes at the individual pixel level. This data model can also integrate raster datasets from heterogeneous sources under a unified framework. The proposed data model consists of several object classes under a hierarchical structure. Each object class is associated with specific properties and behaviors to facilitate efficient spatio‐temporal analyses. We apply this data model to a case study of analyzing the impact of the 2007 freeze in Knoxville, Tennessee. The characteristics of different vegetation clusters before, during, and after the 2007 freeze event are compared. Our findings indicate that the majority of the study area is impacted by this freeze event, and different vegetation types show different response patterns to this freeze. 相似文献
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《制图学和地理信息科学》2013,40(3):123-144
Geographic information system (GIS) applications for risk evaluation concerning environmental and ecological health are appearing with greater frequency. In this paper, we devise a conceptual framework for risk evaluation that encompasses and synthesizes several component frameworks (including risk scoping, risk communication, risk assessment (risk analysis), risk management, and risk monitoring) concerning environmental health, and hence human and ecological impacts. The purpose of devising the framework was to understand better where, when, and how GIS might be used for risk evaluation, and to identify gaps in knowledge requiring further research. An examination of 40 publications shows that most of the research done on the use of GIS for risk evaluation concerned applications in risk assessment rather than risk scoping, management, and risk monitoring. A four-level risk assessment framework is proposed, and criteria for evaluating the work are used to clarify what has been accomplished overall and where research opportunities exist. Future directions for the application of GIS in risk evaluation are suggested. 相似文献
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面向图层处理单元的GIS数据模型、数据处理模式已不再适应大规模海量空间数据组织、处理以及网络分发的需要。文章提出以空间要素基元处理取代传统的面向图层处理的模式,并在对象-关系数据库(ORDBMS)统一框架下构筑、组织、存储、处理空间数据,最终形成基于ORDBMS的GIS应用。 相似文献
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提出一种稀疏自表达方法来研究高光谱影像分类中的波段选择问题。该方法利用字典矩阵等于测量矩阵的条件来改进多观测向量的稀疏表达模型,将波段子集看作高光谱影像波段集合中的代表子集。稀疏自表达方法将波段选择转换为寻求多观测向量中稀疏系数矩阵的非零行向量问题,通过引入混合范数来限定非零元素行向量的个数,利用快速交替方向乘子方法求解稀疏系数矩阵,并聚类非零行向量,实现波段的有效选择。基于两个公开高光谱影像数据集并对比其他4种波段选取方法来验稀疏自表达方法。实验结果证明,稀疏自表达方法能够在计算效率明显优于基于波段相关性的线性限制最小方差方法的同时,取得与该方法和非负稀疏矩阵分解方法相匹甚至略高的总体分类精度。 相似文献
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针对海洋中尺度涡现象,提出一种基于海平面高度异常数据(SLA)的中尺度涡泛克里金提取算法。该算法运用变差函数工具计算SLA变差场,定义为广义振幅场,再利用泛克里金插值消除数据虚警和噪声,借助广义振幅场与实际振幅的关系通过少数几条特征等值线实现涡旋及其属性的提取。选取北太平洋作为实验区,采用2012年4月的4期SLA进行了中尺度涡的定量提取、分析,共提取出841个中尺度涡(含3个多核涡),包含450个气旋涡和391个反气旋涡;与其他遥感提取方法的对比显示北太平洋中尺度涡的成功检测率接近90%,过度检测率小于20%。结果表明:(1)算法具有省时高效性,通过对SLA场的重构创建广义振幅场,避免了等值线筛选过程,相对于海面高度闭合等值线等其他遥感方法具有判据简单及提取速度快的特性;(2)可靠性好,能够通过推导得出的特征等值线确保稳定的提取准确度;算法建立在发展成熟的等值线提取方法之上,并且有变差函数与泛克里金法的理论支撑;(3)自适应性强,可以对任意海区进行实时的涡旋检测和提取,并且除振幅值统计资料及必要基础数据外无需依赖其他辅助性数据。 相似文献
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城市客户空间关系管理探讨 总被引:4,自引:1,他引:4
探讨了利用GIS的空间分析功能,并结合城市人口、社会经济数据,在空间概念上实现客户关系管理的必要性和可行性,提出了客户空间关系管理(CSRM)概念,论述了CSRM系统的基本技术框架和特点,分析了CSRM在企业管理和决策支持方面的主要功能,探索了一条GIS应用于商业分析的新思路。 相似文献
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为进一步分析并评定基于三角网提取的鄂尔多斯块体东北缘垂直形变速率等值线的精度,本文结合基于格网提取的同区域垂直形变速率等值线,分别从数字高程模型(Digital Elevation Model,简称DEM)建立与等值线提取两个角度对研究成果的精度进行对比分析,进而综合两个角度对两种方法提取的垂直形变速率等值线精度进行了差值比较。结果表明,在等值线基值与等值距都相同的条件下,研究区域垂直形变三角网的平均坡度较大,利用三角网提取的垂直形变速率等值线其精度相对较高。 相似文献
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KING GEORGE ISLAND SPATIAL DATA MODEL 总被引:2,自引:0,他引:2
CHEN Nengcheng GONG Jianya 《地球空间信息科学学报》2001,4(2):63-69
1 IntroductionSpatialdistributionisthenaturalfeatureofgeo graphicinformation .Inthepastyears,duetolimi tationoftechnology ,communicationandhardware ,spatialdatacapturedfromdifferentregionhastobesaved ,managedandprocessedinthecentralplace .Asaresult ,spatiald… 相似文献
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Glenn Johnstone 《地球空间信息科学学报》2001,4(2)
1 WhatisAGDI?AtXXIVSCARmeetinginCambridge,inAugust1 996,theWorkingGrouponGeodesyandGeo graphicInformation (WG_GGI)agreedtoanewgeographicdataproject,termed‘geographicdataintegration’ .Theinitialtaskwasto“developaSCAR proposalforthecollection ,integrationandpub… 相似文献
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