一种公寓式建筑物三维产权群集自动构建方法

建筑物在不同视角下分为物理群集和产权群集,后者依附于前者.现有的群集对象构建方法可以自动地构建同一栋建筑物的物理群集和产权群集,但生成的两个群集相互独立.这不仅增加建模成本,也不利于后期模型数据的更新和维护.针对该问题,研究公寓式建筑物物理群集与产权群集的关系,发现连通边界的层级性决定了胞腔聚合的产权体,提出了一种将物...     

地形直接、间接影响的中央区棱柱模型

地形影响的积分算法在中央区存在奇异性,为避免奇异问题可将中央区地形近似为与计算点等高的圆柱体。基于此,提出使用更接近实际网格地形的棱柱模型计算地形影响,并通过推导给出了中央区直接、间接影响的棱柱模型算法公式。当地形网格较小时,棱柱模型与圆柱模型计算的中央区直接影响的差异为正;当地形网格较大时差异为负,但对于中央区间接影响,棱柱模型与圆柱模型计算结果的差异总为负值。当地形高分别取1 000、2 000和3 000 m时,棱柱模型与圆柱模型计算的直接影响差异的极值分别约为±0.3、±0.5和±0.8 m Gal,而间接影响差异的极值分别约为-0.02、-0.12和-0.27 cm。对于高精度的应用需求,当区域海拔较高时建议采用本文提出的更符合实际地形的棱柱模型计算中央区直接、间接影响。     

基于三棱柱的三维地质体建模及可视化研究

建立可视化的三维地质模型是地质信息可视化的一个研究重点,能够为各种地质现象描述提供科学依据。本文主要研究了基于三棱柱的模型构造,提出了三棱柱的改进数据结构和切割的构形以及算法,并且在VC6.0环境下,采用OpenGL作为图形开发工具,实现了三维地质体的可视化,解决了地质体剖切和基坑开挖等问题。     

基于三棱柱的地质体三维交互应用研究

三维交互应用研究是3DGM领域面向应用的研究重点,能够充分展示地质体的三维空间属性,具有重要的实践意义。本文以三棱柱作为基本体元进行建模,讨论了虚拟钻探、虚拟地质剖面、虚拟开挖、虚拟漫游四种在地质领域的应用算法,并且采用VC++和OpenGL作为开发平台模拟实现,解决了工程实践中的一些实际问题。     

一种三维建筑物模型与数据组织方法

针对施工图内容复杂多样,存在图形、文本、符号、表格等多种样式的数据形式,给基于施工图的三维建筑物模型重构带来较大困难的问题,该文分析了建筑施工图的数据内容及其关联性,提出了面向建筑物三维模型重建的数据组织方法,构建了面向数据提取的建筑物对象模型,设计了相应的数据结构和人机交互提取方法,为基于建筑施工图的信息提取提供了一整套可供借鉴的方法。提出了由框架参数、基本参数、扩展参数和语义参数构成的建筑施工图数据参数化分解方法,可以支持内容相对独立的分步参数提取方式,并设计了综合化的交互界面,简化了数据提取操作过程,试验表明有效提高了数据提取的效率和准确率。     

复合面状对象拓扑关系的表达模型

为表达复合面状对象间的细节拓扑关系,对经典9-交集模型进行了改进,给出两种基于分解思想的9-交集模型,其中分解成简单区域的9-交集模型方法相对简单,但表现形式繁琐;分解成点集的9-交集模型的表现形式符合经典9-交集模型,但计算较为复杂。通过示例比较了两种扩展9-交集模型及经典9-交集模型的表达能力。结果表明,两种扩展交集模型均能准确地表达出复合面状对象各子部分之间的拓扑关系的细节,扩充了9-交集模型的表达能力。     

基于COM的3DGIS空间对象模型组件库的设计与实现

提出了一种新的基于3D矢量图形、数字高程模型与数字正射影像相结合的空间对象模型的设计思想,并将COM组件技术引入到该模型的实现中。     

三维城市模型中建筑物LOD模型研究

建筑物模型在三维城市模型(3DCM)中占有相当大的比重,建筑物模型多细节层次(LOD)的建立和表达直接关系到三维城市模型的整体显示效率和真实表现力,是三维城市模型的重要研究内容之一。本文从建筑物模型的纹理特征和几何结构出发,论述了建筑物LOD模型的建立原则,并从应用角度就建筑物各个细节层次模型的特点、应用范围与数据获取等方面进行了分析。     

基于三棱柱11剖分法的海洋温度场动态三维建模方法研究

海水的温度是海洋物理性质中最基本的要素之一,随着对地球研究的逐步深入,数字地球的建模范围也从陆地向海洋延伸,从静态向动态建模发展。由于海洋每时每刻都在变化,对海洋温度场的三维建模尤其是动态三维建模尤为困难。本文分析了海洋温度场数据获取的方法,并从动态温度场数据的特点出发,提出了基于三棱柱11剖分法的海洋温度场动态三维建模方法,提取对象中的等温面作为特征对三维温度场进行建模和表达。实验表明,本文提出的方法可以高效地对动态三维温度场进行建模和表达。     

时态对象结构的代数模型

论述引入元组、集合、序列和时态４个基本构造子来建立时态对象结构的代数模型,同时例证了各种传统时态关系模型向时态对象模型的转化。研究表明,时态对象模型在复杂结构时态语义建模方面比时态关系模型更具优势。     

基于Snake模型的建筑物群移位算法改进研究

在对Snake模型研究的基础上,结合建筑物群在移位中的特点,从2个方面对Snake模型进行改进:首先,在Snake模型中加强对齐排列建筑物群这一重要空间特征的识别,以便保持对齐排列建筑物群在移位前后不变;其次,针对传统Snake模型有时无法解决两个建筑物空间冲突的缺点,对街区中的建筑物群实行分层次移位,先将有冲突的两个建筑物作为整体,与剩余其它建筑物利用Snake模型一起移位,然后再根据文中提出的建筑物间相互冲突的4种受力模型,进行建筑物间空间冲突的移位。最后利用改进的Snake模型进行移位实验和分析。     

An improved direction relation detection model for spatial objects

Direction is a common spatial concept that is used in our daily life. It is frequently used as a selection condition in spatial queries. As a result, it is important for spatial databases to provide a mechanism for modeling and processing direction queries and reasoning. Depending on the direction relation matrix, an inverted direction relation matrix and the concept of direction pre- dominance are proposed to improve the detection of direction relation between objects. Direction predicates of spatial systems are also extended. These techniques can improve the veracity of direction queries and reasoning. Experiments show excellent efficiency and performance in view of direction queries.     

An improved direction relation detection model for spatial objects

Direction is a common spatial concept that is used in our daily life. It is frequently used as a selection condition in spatial queries. As a result, it is important for spatial databases to provide a mechanism for modeling and processing direction queries and reasoning. Depending on the direction relation matrix, an inverted direction relation matrix and the concept of direction pre- dominance are proposed to improve the detection of direction relation between objects. Direction predicates of spatial systems are also extended. These techniques can improve the veracity of direction queries and reasoning. Experiments show excellent efficiency and performance in view of direction queries.     

一种改进遗传神经网络的建筑基坑沉降预测模型

目前常见的沉降预测方法有灰色系统模型、时间序列分析法、BP神经网络及其改进算法等。针对BP神经网络容易出现过拟合和局部最优的缺点,部分学者利用遗传算法进行神经网络初始权值和阈值优化。但是遗传算法对于因监测数据质量问题而造成变形预测结果不佳的优化效果有限。因此引入自适应增强算法对遗传神经网络预测模型进行改进。并利用某高层建筑基坑实测50期监测数据进行仿真预测。实验结果表明,利用自适应增强算法改进之后的遗传神经网络预测模型在满足工程监测精度要求的前提下,在MAPE、MAE、MSE三项精度指标上分别提高80.57%、81.04%、70.83%。     

An efficient solution for building polygonal objects

Polygonal object is a fundamental type of geometric data in vector GIS. The key step of cleaning topological relationship after data collection of polygonal layer is to build polygonal objects from digital arcs. The raw digital arcs may intersect with each other. The algorithm for building polygonal objects after the raw arcs have been split at all intersections is presented. The build-up of polygonal objects in this paper is designed to be implemented by two steps. The first step is to extract all the polygons needed for build-up of polygonal objects from arcs. The second step is to organize polygonal objects from these polygons. For the first step, a tracing algorithm is proposed. The algorithm merely extracts the polygons needed for the build-up of polygonal objects, which is a subset of all the possible polygons that can be induced from the arcs. For the second step, an algorithm based on a specially designed order of polygons is advanced. All the topological relationships among the polygons are sho     

An efficient solution for building polygonal objects

Polygonal object is a fundamental type of geometric data in vector GIS. The key step cleaning topological relationship after data collection of polygonal layer is to build polygonal objects from digital arcs. The raw digital arcs may intersect with each other. The algorithm for building polygonal objects after the raw arcs have been split at all intersections is presented. The build-up of polygonal objects in this paper is designed to be implemented by two steps. The first step is to extract all the polygons needed for build-up of polygonal objects from arcs. The second step is to organize polygonal objects from these polygons. For the first step, a tracing algorithm is proposed. The algorithm merely extracts the polygons needed for the build-up of polygonal objects, which is a subset of all the possible polygons that can be induced from the arcs. For the second step, an algorithm based on a specially designed order of polygons is advanced. All the topological relationships among the polygons are shown in a single scan. Experiments show that the two algorithms together offer a robust and efficient solution for building polygonal objects from intersected arcs.     

免棱镜全站仪在建筑物倾斜监测中应用与分析

随着科学技术的发展,现代高层建筑物日益呈现出结构的复杂性和风格的多样性,对高层建筑物的倾斜监测精度和方法也提出了新的要求.免棱镜全站仪具有对空间目标"所瞄即所测"快捷、高效的特性,应用于高层建筑物的倾斜监测,并经实际工程测试与分析,得出有益的结论.     

Displacement of building cluster using field analysis method

This paper presents a field based method to deal with the displacement of building cluster, which is driven by the street widening. The compress of street boundary results in the force to push the building moving inside and the force propagation is a decay process. To describe the phenomenon above, the field theory is introduced with the representation model of isoline. On the basis of the skeleton of Delaunay triangulation, the displacement field is built in which the propagation force is related to the adjacency degree with respect to the street boundary. The study offers the computation of displacement direction and offset distance for the building displacement. The vector operation is performed on the basis of grade and other field concepts.     

Displacement of building cluster using field analysis method

This paper presents a field based method to deal with the displacement of building cluster, which is driven by the street widening. The compress of street boundary results in the force to push the build-ing moving inside and the force propagation is a decay process.To describe the phenomenon above,the field theory is introduced with the representation model of isoline.On the basis of the skeleton of Delaunay triangulation.the displacement field is built in which the propagation force is related to the adjacency degree with respect to the street boundary.The study offers the computation of displacement direction and offset distance for the building displacement.The vector operation is performed on the basis of grade and other field concepts.     

利用结构面对象的高分遥感影像建筑物变化检测

根据建筑物具有丰富的角点和规则的外观形状的特点,本文提出了依据线段信息生成建筑物变化检测基本单元——结构面对象的建筑物变化检测方法.从高分遥感影像中提取出建筑物的边缘线及屋顶外形线条,生成结构面对象并提取其在两时相影像中相应的特征信息,通过监督分类获取变化建筑区域.试验结果表明,利用结构面对象进行建筑物变化检测能较完整...