共查询到20条相似文献，搜索用时 21 毫秒
1.
面向交通地理信息时空特征描述的Spatial-UML研究 总被引：1，自引：1，他引：0
空间信息系统建模的多样性、主流信息技术的高度集成性以及逐渐变复杂的系统体系都使得软件和数据库设计者向可视化建模的主流方向发展。分析面向地理信息时空特征描述而建立的空间可视化语言插件(SpatialPVLs),并基于可视化建模技术标准,应用统一建模语言(UML)内置的扩展机制实现了针对地理信息时空特征描述的扩展。UML和SpatialPVLs的集成过程定义了面向地理信息时空特征描述的可视化建模语言,即Spatial-UML。最后,以城市交通模拟地理信息系统(GIS)数据概念模型设计为实例,验证Spatial-UML的适用性和扩展性,建立一个可以满足不同领域用户访问和理解的互协作建模架构,实现交通地理对象的空间、时态和时空特征的可视化标准描述和表达。 相似文献
2.
Rémy Thibaud Géraldine Del Mondo Thierry Garlan Ariane Mascret Christophe Carpentier 《Transactions in GIS》2013,17(5):742-762
Defining a model for the representation and the analysis of spatio‐temporal dynamics remains an open domain in geographical information sciences. In this article we investigate a spatio‐temporal graph‐based model dedicated to managing and extracting sets of geographical entities related in space and time. The approach is based on spatial and temporal local relations between neighboring entities during consecutive times. The model allows us to extract sets of connected entities distant in time and space over long periods and large spaces. From GIS concepts and qualitative reasoning on space and time, we combine the graph model with a dedicated spatial database. It includes information on geometry and geomorphometric parameters, and on spatial and temporal relations. This allows us to extend classical measurements of spatial parameters, with comparisons of entities linked by complex relations in space and time. As a case study, we show how the model suggests an efficient representation of dunes dynamics on a nautical chart for safe navigation. 相似文献
3.
A spatial panel ordered-response model with application to the analysis of urban land-use development intensity patterns 总被引：1，自引：0，他引：1
This paper proposes and estimates a spatial panel ordered-response probit model with temporal autoregressive error terms to analyze changes in urban land development intensity levels over time. Such a model structure maintains a close linkage between the land owner’s decision (unobserved to the analyst) and the land development intensity level (observed by the analyst) and accommodates spatial interactions between land owners that lead to spatial spillover effects. In addition, the model structure incorporates spatial heterogeneity as well as spatial heteroscedasticity. The resulting model is estimated using a composite marginal likelihood (CML) approach that does not require any simulation machinery and that can be applied to data sets of any size. A simulation exercise indicates that the CML approach recovers the model parameters very well, even in the presence of high spatial and temporal dependence. In addition, the simulation results demonstrate that ignoring spatial dependency and spatial heterogeneity when both are actually present will lead to bias in parameter estimation. A demonstration exercise applies the proposed model to examine urban land development intensity levels using parcel-level data from Austin, Texas. 相似文献
4.
In the integrated framework presented in this article, a geographical information system serves as a shell to integrate spatial, dynamic and stochastic perspectives of biological invasions in a coherent workflow. A decision tree model stratifies the landscape with respect to spatial susceptibility and builds the spatial biophysical structure for the simulation of species invasion. A dynamic diffusion model evaluates the temporal changes of species to provide the dynamic parameters for the simulation. A simulation model derived from percolation theory simulates species invasion by combining spatial and dynamic information, and explicitly representing spatio‐temporal patterns of invasions within the GIS‐percolation environment. The simulation illustrates the great influence of spatial structure and connectivity of landscape on the diffusion of the species. 相似文献
5.
传统地形TIN离散、独立的三角形结构限制了空间实体、空间关系的表达能力,分析和操作也比较困难,应用大多限制在可视化、渲染和光照分析等方面。由于不可能通过简单地扩展和改进现有模型来满足TIN中对空间实体关系表达的需求,从面向对象的角度出发,利用单纯剖分理论对TIN进行了实体划分和拓扑建模,使TIN具有了地理对象结构从而能够进行地理实体的表达与分析,建立了对象化不规则三角网(OTIN)与Euler示性数方向模型(EDM),使得TIN不但可以较好地表达地形起伏信息,还具有实体性和对象性,便于进行空间查询与分析。 相似文献
6.
A Space‐Time Raster GIS Data Model for Spatiotemporal Analysis of Vegetation Responses to a Freeze Event 
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下载免费PDF全文 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
7.
A Hybrid Spatio-Temporal Data Model and Structure (HST-DMS) for Efficient Storage and Retrieval of Land Use Information 总被引：1，自引：0，他引：1
While the incorporation of geographical and environmental modeling with GIS requires software support for storage and retrieval of spatial information that changes over time, it continues to be an unresolved issue with modern GIS software. Two complementary approaches have been used to manage the spatial and temporal heterogeneity within datasets that use a field‐based representation of the world. Some researchers have proposed new data models that partition space into discrete elements on an as‐needed basis following each temporal event, while others have focused on eliminating duplication of repeated data elements present in spatio‐temporal information. It is proposed in this paper that both approaches have merit and can be combined to create a Hybrid Spatio‐Temporal Data Model and Structure (HST‐DMS) that efficiently supports spatio‐temporal data storage and querying. Specifically, Peuquet and Duan's (1995) Event‐based Spatio‐Temporal Data Model (ESTDM) and the Overlapping R‐tree (Guttman 1984, Tzourmanis et al. 2000) are utilized to create a prototype used to store information about urban expansion for the town of Carbondale, Illinois. 相似文献
8.
Design and implementation of a Space-Time Intelligence System for disease surveillance 总被引：2，自引：0，他引：2
Geoffrey M. Jacquez Dunrie A. Greiling Andrew M. Kaufmann 《Journal of Geographical Systems》2005,7(1):7-23
Modeling chronic and infectious diseases entails tracking and describing individuals and their attributes (such as disease status, date of diagnosis, risk factors and so on) as they move and change through space and time. Using Geographic Information Systems, researchers can model, visualize and query spatial data, but their ability to address time has been limited by the lack of temporal referencing in the underlying data structures. In this paper, we discuss issues in designing data structures, indexing, and queries for spatio-temporal data within the context of health surveillance. We describe a space-time object model that treats modeled individuals as a chain of linked observations comprised of an ID, space-time coordinate, and time-referenced attributes. Movement models for these modeled individuals are functions that may be simple (e.g. linear, using vector representation) or more complex. We present several spatial, temporal, spatio-temporal and epidemiological queries emergent from the data model. We demonstrate this approach in a representative application, a simulation of the spread of influenza in a hospital ward.This research was supported by grant R44ES010220 from the National Institute of Environmental Health Sciences (NIEHS) and by grants R01CA092669 and R01CA96002 from the National Cancer Institute (NCI). The content of this paper does not necessarily represent the official views of the NIEHS or the NCI. 相似文献
9.
Dynamic geospatial complex systems are inherently four‐dimensional (4D) processes and there is a need for spatio‐temporal models that are capable of realistic representation for improved understanding and analysis. Such systems include changes of geological structures, dune formation, landslides, pollutant propagation, forest fires, and urban densification. However, these phenomena are frequently analyzed and represented with modeling approaches that consider only two spatial dimensions and time. Consequently, the main objectives of this study are to design and develop a modeling framework for 4D agent‐based modeling, and to implement the approach to the 4D case study for forest‐fire smoke propagation. The study area is central and southern British Columbia and the western parts of Alberta, Canada for forest fires that occurred in the summer season of 2017. The simulation results produced realistic spatial patterns of the smoke propagation dynamics. 相似文献
10.
Misspecifications in interaction model distance decay relations: A spatial structure effect 总被引：1，自引：0，他引：1
M. Tiefelsdorf 《Journal of Geographical Systems》2003,5(1):25-50
An exclusively statistical approach is proposed to address the spatial structure effects of general interaction models. It is shown that the spatial heterogeneity in the estimated region-specific distance decay
parameters may in part be due to the combination of two factors: (a) a functional mis-specification of the global distance
decay relationship; and (b) the heterogeneity in the region-specific conditional distance distributions. A properly specified
global distance decay function allows controlling for these spatially induced biases in the local distance decay parameters.
However, inherent multicollinearities between the set of region specific distance decay parameters and other estimated model
parameters prevent an unambiguous interpretation. A key conclusion is that a proper model specification, in particular, the
specification of the global distance decay relationship, is of paramount importance in interaction modeling and for accessibility
studies.
Received: September 2002 / Accepted: January 2003 相似文献
11.
连续多尺度表达是当前地图制图领域中的热点问题之一,常规地图采用多级瓦片剖分、多版本存储技术实现空间多尺度表达,存在数据量冗余、跨级别不一致、瓦片间尺度跳跃大等问题。结合传统地图综合、多尺度表达数据结构和空间索引建立等多种策略,在目标数据模型中加入尺度维和操作信息,记录地图综合的过程和尺度变换,建立空间数据矢量金字塔模型。该模型离线综合获取多级基态尺度表达数据,确定每个目标的尺度表达空间范围,并通过面向对象建模技术将目标表达状态及其纵向关联关系、算子类型及控制参量等信息封装在多尺度目标中;同时,建立一端或两端控制的尺度变换结构。基于该模型可快速获取适应用户需求的连续尺度表达状态。 相似文献
12.
This paper integrates genetic algorithm and neural network techniques to build new temporal predicting analysis tools for
geographic information system (GIS). These new GIS tools can be readily applied in a practical and appropriate manner in spatial
and temporal research to patch the gaps in GIS data mining and knowledge discovery functions. The specific achievement here
is the integration of related artificial intelligent technologies into GIS software to establish a conceptual spatial and
temporal analysis framework. And, by using this framework to develop an artificial intelligent spatial and temporal information
analyst (ASIA) system which then is fully utilized in the existing GIS package. This study of air pollutants forecasting provides
a geographical practical case to prove the rationalization and justness of the conceptual temporal analysis framework. 相似文献
13.
针对雷达探测范围会受到复杂地形因素影响,单一地依靠电磁传播模型可视化雷达探测区域很难真实有效地展现电磁覆盖情况的问题,该文提出一种基于GeoSOT-3D空间剖分的雷达探测范围的计算与表达一体化的真三维模型。GeoSOT-3D剖分框架将上至地球50 000km,下至地心的全部地球空间划分成多层次、多尺度空间体元,体元可承载多源异构空间数据。依据GeoSOT-3D的剖分流程,将地形数据、雷达探测空间数据离散化。最后,开发了雷达探测范围可视化验证平台。实验结果表明,该建模方法对复杂的地形适应性强,可视化表现效果真实直观。 相似文献
14.
This paper integrates genetic algorithm and neural network techniques to build new temporal predicting analysis tools for geographic information system (GIS). These new GIS tools can be readily applied in a practical and appropriate manner in spatial and temporal research to patch the gaps in GIS data mining and knowledge discovery functions. The specific achievement here is the integration of related artificial intelligent technologies into GIS software to establish a conceptual spatial and temporal analysis framework. And, by using this framework to develop an artificial intelligent spatial and temporal information analyst (ASIA) system which then is fully utilized in the existing GIS package. This study of air pollutants forecasting provides a geographical practical case to prove the rationalization and justness of the conceptual temporal analysis framework. 相似文献
15.
This paper integrates genetic algorithm and neural network techniques to build new temporal predicting analysis tools for geographic information system (GIS). These new GIS tools can be readily applied in a practical and appropriate manner in spatial and temporal research to patch the gaps in GIS data mining and knowledge discovery functions. The specific achievement here is the integration of related artificial intelligent technologies into GIS software to establish a conceptual spatial and temporal analysis framework. And, by using this framework to develop an artificial intelligent spatial and temporal information analyst (ASIA) system which then is fully utilized in the existing GIS package. This study of air pollutants forecasting provides a geographical practical case to prove the rationalization and justness of the conceptual temporal analysis framework. 相似文献
16.
Spatial prediction is commonly used in social and environmental research to estimate values at unobserved locations using sampling data. However, most existing spatial prediction methods and software packages are based on the assumption of spatial autocorrelation (SAC), which may not apply when spatial dependence is weak or non-existent. In this article, we develop a modeling framework for spatial prediction based on spatial stratified heterogeneity (SSH), a common feature of geographical variables, as well as an R package called sandwichr that implements this framework. For populations that can be stratified into homogeneous strata, the proposed framework enables the estimation of values for user-defined reporting units (e.g., administrative units or grid cells) based on the mean of each stratum, even if SAC is weak or absent. The estimated values can be used to create predicted surfaces and mapping. The framework also includes procedures for selecting appropriate stratifications of the populations and assessing prediction uncertainty and model accuracy. The sandwichr package includes functions to implement each step of the framework, allowing users to implement SSH-based spatial prediction effectively and efficiently. Two case studies are provided to illustrate the effectiveness of the proposed framework and the sandwichr package. 相似文献
17.
交通是GIS技术最重要的应用领域之一,本文首先对城市交通网络空间数据模型进行了分类,然后介绍了近年来城市交通网络空间数据模型研究在导航数据库、时态数据处理、多模式交通网络表达等方面的主要进展。 相似文献
18.
植被遥感辐射传输建模中的异质性研究进展 总被引：1，自引：0，他引：1
遥感辐射传输建模是在研究电磁波与地物相互作用机理的基础上,建立遥感观测信号与地物属性、地物结构和观测几何等参量之间定量关系的模型,是理解遥感观测信号和反演地表参量的理论基础。近年来空间异质性问题引起了定量遥感领域的高度关注,高分辨率卫星及激光雷达等数据的日益丰富给研究空间异质性提供了有力支撑。在异质性植被场景遥感辐射传输建模过程中,像元内部的组分比例、3维结构、空间格局以及端元边界处的阴影效应与散射过程等方面是需要重点考虑的因素。本文在总结非均质地表空间异质性描述的基础上,分别总结了植被二向性反射与热红外辐射方向性建模研究的发展历程,以及非均质地表植被遥感建模研究的最新进展,并指出了地表遥感建模中研究异质性问题的发展方向。 相似文献
19.
The mixed pixel problem affects the extraction of land cover information from remotely sensed images. Super-resolution mapping (SRM) can produce land cover maps with a finer spatial resolution than the remotely sensed images, and reduce the mixed pixel problem to some extent. Traditional SRMs solely adopt a single coarse-resolution image as input. Uncertainty always exists in resultant fine-resolution land cover maps, due to the lack of information about detailed land cover spatial patterns. The development of remote sensing technology has enabled the storage of a great amount of fine spatial resolution remotely sensed images. These data can provide fine-resolution land cover spatial information and are promising in reducing the SRM uncertainty. This paper presents a spatial–temporal Hopfield neural network (STHNN) based SRM, by employing both a current coarse-resolution image and a previous fine-resolution land cover map as input. STHNN considers the spatial information, as well as the temporal information of sub-pixel pairs by distinguishing the unchanged, decreased and increased land cover fractions in each coarse-resolution pixel, and uses different rules in labeling these sub-pixels. The proposed STHNN method was tested using synthetic images with different class fraction errors and real Landsat images, by comparing with pixel-based classification method and several popular SRM methods including pixel-swapping algorithm, Hopfield neural network based method and sub-pixel land cover change mapping method. Results show that STHNN outperforms pixel-based classification method, pixel-swapping algorithm and Hopfield neural network based model in most cases. The weight parameters of different STHNN spatial constraints, temporal constraints and fraction constraint have important functions in the STHNN performance. The heterogeneity degree of the previous map and the fraction images errors affect the STHNN accuracy, and can be served as guidances of selecting the optimal STHNN weight parameters. 相似文献
20.
GIS时空分析系统的Clifford代数设计与实现 总被引：2，自引：0，他引：2
以Clifford代数为理论基础与数学工具,构建了时空分析原型系统：①在兼容多类常用GIS数据格式的基础上,根据Clifford代数空间构建的思想,对现有时空数据模型进行扩展,实现了时间、空间与属性的一体化表达;②定义了可支撑多维度时空分析的几何、度量等Clifford代数算子库;③基于插件的时空分析模型算法构建及集成框架,实现了高维邻域分析、网络分析以及时空栅格数据分析等地学分析算法。实验结果显示,根据Clifford代数所构建的时空分析系统可有效支撑多维时空分析。 相似文献