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1.
田江鹏  游雄  贾奋励  夏青 《测绘学报》2016,45(11):1352-1360
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   

2.
 Activity-based models consider travel as a derived demand from the activities households need to conduct in space and time. Over the last 15 years, computational or rule-based models of activity scheduling have gained increasing interest in time-geography and transportation research. This paper argues that a lack of techniques for deriving rules from empirical data hinders the further development of rule-based systems in this area. To overcome this problem, this paper develops and tests an algorithm for inductively deriving rules from activity-diary data. The decision table formalism is used to exhaustively represent the theoretically possible decision rules that individuals may use in sequencing a given set of activities. Actual activity patterns of individuals are supplied to the system as examples. In an incremental learning process, the system progressively improves on the selection of rules used for reproducing the examples. Computer experiments based on simulated data are performed to fine-tune rule selection and rule value update functions. The results suggest that the system is effective and fairly robust for parameter settings. It is concluded, therefore, that the proposed approach opens up possibilities to derive empirically tested rule-based models of activity scheduling. Follow-up research will be concerned with testing the system on empirical data. Received: 31 January 2001 / Accepted: 13 September 2001  相似文献   

3.
基于支持向量机的元胞自动机及土地利用变化模拟   总被引:11,自引:0,他引:11  
杨青生  黎夏 《遥感学报》2006,10(6):836-846
提出了利用遥感数据,并采用支持向量机来确定元胞自动机非线性转换规则的新方法。元胞自动机在模拟复杂地理现象时,需要采用非线性转换规则。目前元胞自动机主要采用线性方法来获取转换规则,在反映复杂的非线性地理现象时有一定的局限性。以城市扩张的模拟为例,将模拟城市系统的主要特征变量映射到Hilbert空间后,通过SVM建立最优分割超平面,分割超平面的分类决策函数由径向基核(Radial Basis Kernel)构造。利用历史遥感数据校正超平面的决策函数,确定城市元胞自动机的非线性转换规则,计算出城市发展概率。利用所提出的方法,对深圳市1988-2010年的城市发展进行了模拟,取得了较理想的模拟效果。研究结果表明,基于SVM-CA模型的模拟精度比传统MCE方法模拟精度高,MoranⅠ指数与实际更为接近。  相似文献   

4.
This paper presents a spatial autoregressive (SAR) method-based cellular automata (termed SAR-CA) model to simulate coastal land use change, by incorporating spatial autocorrelation into transition rules. The model captures the spatial relationships between explained and explanatory variables and then integrates them into CA transition rules. A conventional CA model (LogCA) based on logistic regression (LR) was studied as a comparison. These two CA models were applied to simulate urban land use change of coastal regions in Ningbo of China from 2000 to 2015. Compared to the LR method, the SAR model yielded smaller accumulated residuals that showed a random distribution in fitting the CA transition rules. The better-fitting SAR model performed well in simulating urban land use change and scored an overall accuracy of 85.3%, improving on the LogCA model by 3.6%. Landscape metrics showed that the pattern generated by the SAR-CA model has less difference with the observed pattern.  相似文献   

5.
 This paper reports the results of an empirical comparison of various types of competing risk models in predicting the timing and duration of activities. In particular, three types of models are compared: a non-competing risk model, an unconditional competing risk model, and a conditional competing risk model. The models are applied to an activity diary, collected in the Netherlands. The results of the comparison indicate that the conditional competing risk model performs best, indicating that the choice and timing of activities depends on the nature and duration of the activity conducted previously. The specific structure of these dependent transition probabilities are discussed in detail. Several socio-demographic variables are found to be significantly related to the transition probabilities. Received: 19 July 2001 / Accepted: 25 January 2002  相似文献   

6.
基于数据同化的元胞自动机   总被引:4,自引:2,他引:2  
提出基于集合卡尔曼滤波(EnKF)的元胞自动机(CA)模型。在CA模型中,由于不同的样本会训练出不同参数值 的转换规则,且获取的转换规则在整个模拟过程中不能改变等原因,误差在模拟过程中会不断累积。本文在CA模型中 引入集合卡尔曼滤波的数据同化方法,建立了基于集合卡尔曼滤波的数据同化CA模型,同化遥感观测数据,根据得出 的同化值修正模拟结果使之向真实情况逼近。利用该模型模拟了广东省东莞市的发展情景(1995年—2005年),实验表 明,与传统CA模型相比,基于集合卡尔曼滤波的CA模型能够融合遥感观测数据,并能更有效地模拟城市扩张过程,达 到良好的模拟效果。  相似文献   

7.
阐述坐标转换的常用模型,分析线性化坐标转换模型的模型误差,给出这种误差对旋转参数限制的最大旋转角度。首次将同伦算法应用于坐标转换模型中,提出基于同伦算法的非线性坐标转换模型,避免线性化所带来的模型误差,解决在大角度旋转情况下线性化模型不能使用的问题。数据计算表明,文中提出的非线性坐标转换模型同伦方法是削弱坐标转换误差,高精度求解坐标转换参数的有效方法。  相似文献   

8.
The first development stages of the low cost, PC based, near real time photogrammetry system, PHOENICS, are discussed. Hardware and software components are described and planned system enhancement stages are sketched out. Concepts employed for target detection and analysis are briefly discussed. A target centre detection technique in which a combination of original and thresholded image is employed and a target design especially suited for thresholding techniques are presented. The introduction of parallel processing hardware into PHOENICS during the enhancement phase is explained. Accuracies achieved in first experiments with the prototype of PHOENICS are reported.  相似文献   

9.
空间目标的聚合模型   总被引:2,自引:0,他引:2  
李霖 《测绘学报》1997,26(4):337-343
本文定义了集合元素的聚合算子,简述其特性,以此聚合算子为基础,提出了空间目标的聚合模型。根据GIS空间目标的属性,分析了聚合算子的表现形式。由此模型的特点可以得出:聚合模型适合于GIS层次数据的组织,它能减少数据的冗余和维护数据的一致性。经概念及含义的比较,指出了面向对象的模型方法很适合此聚合模型的实施。  相似文献   

10.
Extraction of buildings from LIDAR data has been an active research field in recent years. A scheme for building detection and reconstruction from LIDAR data is presented with an object-oriented method which is based on the buildings' semantic rules. Two key steps are discussed: how to group the discrete LIDAR points into single objects and how to establish the buildings' semantic rules. In the end, the buildings are reconstructed in 3D form and three common parametric building models (flat, gabled, hipped) are implemented.  相似文献   

11.
12.
Successful implementation of an intelligent system for automated map generalization requires formalization of cartographic principles that are, in many cases, only intuitively understood. Formalizing these principles requires acquisition and re-expression in the form of semantic nets, frames, production rules, or similar formalization methods. The various techniques for cartographic knowledge acquisition have been discussed on a theoretical basis; however, little empirical research has been conducted. This paper reports on empirical acquisition of cartographic knowledge by reverse engineering; that is, on trying to recapitulate decisions made on published documents or maps. The work is based on a computer-assisted multi-scale inventory of the Austrian National Topographic Map Series. Queries of the relational database, within which inventory data are stored, lead to the formulation of prototype production rules for modifying map symbols during automatic scale changes. Components of map generalization expressed in such rules include the selection behavior of settlement, transportation, and hydrographic objects, and the degree of simplification of settlement domains and building clusters. The acquired cartographic knowledge reveals quantitative relations between map elements and the changes in these relations that occur with scale transition. These insights can guide subsequent knowledge refinement using other acquisition methods. This paper provides, in addition, a conceptual framework by which other topographic map series may be compared at multiple scales.  相似文献   

13.
在城市土地利用认知基础上,本文将ECA-GIS模型的时空数据模型应用于城市土地利用演变模拟中,论述了ECA-GIS模型在模拟土地利用时空演变上的规则,并设计了基于ECA-GIS模型的城市土地利用演化模型,研究了ECA-GIS模型在土地利用演变上的模拟方法和过程。  相似文献   

14.
将自然语言描述的知识规则应用于计算机处理时,需要将非结构化语言转换为结构化语言。对于面向特定领域的、具有空间关系的规则,还需要消除两种语言之间的空间信息语义障碍。本文以城市规划领域的知识规则为例,提出知识单元概念、构建具有空间关系的知识单元体系结构、提炼面向领域的知识单元组合模式。在此基础上,建立自然语言解析模型,实现将自然语言描述的领域规则转化为知识单元组合模式,进而解析成面向GIS查询、分析、操作的结构化的计算机语言。  相似文献   

15.
 The solutions of the CODE Analysis Center submitted to the IGS, the International Global Position System (GPS) Service for Geodynamics, are based on three days of observation of about 80–100 stations of the IGS network. The Earth rotation parameters (ERPs) are assumed to vary linearly over the three days with respect to an a priori model. Continuity at the day boundaries as well as the continuity of the first derivatives are enforced by constraints. Since early April 1995 CODE has calculated a new ERP series with an increased time resolution of 2 hours. Again continuity is enforced at the 2-hours-interval boundaries. The analysis method is described, particularly how to deal with retrograde diurnal terms in the ERP series which may not be estimated with satellite geodetic methods. The results obtained from the first year of data covered by the time series (time interval from 4 April 1995 to 30 June 1996) are also discussed. The series is relatively homogeneous in the sense of the used orbit model and the a priori model for the ERPs. The largest source of excitation at daily and sub-daily periods is likely to be the effect of the ocean tides. There is good agreement between the present results and Topex/Poseidon ocean tide models, as well as with models based on Very Long Baseline Interferometry (VLBI) and Satellite Laser Ranging (SLR) data. Non-oceanic periodic variations are also observed in the series. Their origin is most probably a consequence of the GPS solution strategy; other possible sources are the atmospheric tides. Received: 13 July 1999 / Accepted: 21 March 2000  相似文献   

16.
IntroductionThanks to a large number of applications ,suchas map updating, urban planning or land useanalysis ,extraction of artificial objects ,such asbuildings ,roads fromthei mages has been an ac-tive research field for many years . Since build-ings ar…  相似文献   

17.
Recently a national 3D standard was established in the Netherlands as a CityGML Application Domain Extension (called IMGeo). In line with the Dutch practice of modeling geo‐information, the ADE is developed using a model driven approach. The classes are designed in UML and automatically mapped to GML schema. The current OGC CityGML specification does not provide rules or guidance on correctly modeling an ADE in UML. This article fills this gap by studying how CityGML can be extended for specific applications starting from the UML diagrams. Six alternatives for modeling ADEs in UML are introduced and compared. The optimal alternative is selected and applied to obtain the national 3D standard. The approach was extensively discussed with international experts, who were members of both SIG3D and other working groups. As a consequence the approach was adopted by the SIG3D, the Special Interest Group 3D which, among other things, work on the 3D standard CityGML in cooperation with OGC. Therefore the approach contains many issues that can be generalized and reused by future domain extensions of CityGML. To further support this, the article formulates a model‐driven framework to model CityGML ADEs. Open issues are described in the conclusions.  相似文献   

18.
The dynamic relationships between land use change and its driving forces vary spatially and can be identified by geographically weighted regression (GWR). We present a novel cellular automata (GWR-CA) model that incorporates GWR-derived spatially varying relationships to simulate land use change. Our GWR-CA model is characterized by spatially nonstationary transition rules that fully address local interactions in land use change. More importantly, each driving factor in our GWR model contains effects that both promote and resist land use change. We applied GWR-CA to simulate rapid land use change in Suzhou City on the Yangtze River Delta from 2000 to 2015. The GWR coefficients were visualized to highlight their spatial patterns and local variation, which are closely associated with their effects on land use change. The transition rules indicate low land conversion potential in the city’s center and outer suburbs, but higher land conversion potential in the inner near suburbs along the belt expressway. Residual statistics show that GWR fits the input data better than logistic regression (LR). Compared with an LR-based CA model, GWR-CA improves overall accuracy by 4.1% and captures 5.5% more urban growth, suggesting that GWR-CA may be superior in modeling land use change. Our results demonstrate that the GWR-CA model is effective in capturing spatially varying land transition rules to produce more realistic results, and is suitable for simulating land use change and urban expansion in rapidly urbanizing regions.  相似文献   

19.
在综述移动GIS研究发展现状的基础上,本文首先分析了C/S模式移动GIS和B/S模式GIS的优缺点,认为在移动环境的特点下,C/S模式更适合于当前移动GIS的开发。由此,探讨了基于C/S模式移动GIS模型的关键技术与实现,包括移动定位技术、嵌入式GIS开发技术以及数据通信技术等,并以城市导游导航为应用实例进行了说明,验证了本文提出方法的可行性和正确性。  相似文献   

20.
王圭  童小华陈鹏 《东北测绘》2007,30(6):51-55,58
在综述移动GIS研究发展现状的基础上,本文首先分析了C/S模式移动GIS和B/S模式GIS的优缺点.认为在移动环境的特点下,C/S模式更适合于当前移动G1S的开发。由此,探讨了基于C/S模式移动GIS模型的关键技术与实现,包括移动定位技术、嵌入式G1S开发技术以及数据通信技术等,并以城市导游导航为应用实例进行了说明,验证了本文提出方法的可行性和正确性。  相似文献   

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