Distortion visualization techniques for 3D coherent sets: A case study of 3D building property units

In the fields of 3D cadastre and 3D property management system, numerous building property objects are adjacent as primary property units assemble into a 3D coherent set. During visualization process of the coherent set, occlusion, obscure, mazy spatial relationships and relative location relationships among the units of the coherent set cause difficulty in observing and understanding the set and its units. Common 3D objects viewing method, such as rotation and navigation obtaining desired visualization effects through adjusting the view angle and position of the camera's field of view, provides weak interactive experience and orientation control for the coherent set because of the neighbour relationships of the 3D objects inside the set. In this paper, a novel method is proposed to solve the prior problems with two basic distortion methods based on “focus + context” theory. The coherent set is first discretized into individual objects and changed them locations according to linear or orthogonal function, while keeping their relative location and dual topological relationships. To maintain both global context awareness (topology and locations) of 3D coherent set and highlight effect of the focus 3D building property object, three evaluation indexes are adopted to assess the corresponding distortion results. A case study based on the real clustered 3D property in Shenzhen was conducted to evaluate the performance of distortion functions, the result shows that the method proposed in this article can not only expand the visual area of focused object and create a clear line of sight (LOS) to the focal object previously obscured, but also maintain verticality and proximity in some degree to facilitate understand the spatial occupation and distribution of whole coherent objects.     

深圳市公交票价及财政政策研究

面对越来越严峻的城市交通形势,深圳政府已经认识到必须要加大对公交行业的投入,以建立可以与私人交通方式相竞争的公交体系。其中,公交票价和财政政策是非常重要的研究内容。鉴此就深圳目前面临的票价和财政问题,结合国外发达国家的相关经验,在对整个行业形势和交通政策进行深入研究的基础上,提出适合深圳发展的关于公交票价和财政政策方面的建议,使政府、公交公司、乘客三者之间能取得一个较好的平衡点。     

型钢混凝土结构异型箍筋施工技术

深圳国际商会中心，位于深圳市福田中心区，是一座超高层写字楼，为CBD商务中心区的标志性建筑。该工程地下3层，地上55层，建筑面积134081m^2，建筑高度214．5m，主楼为框筒结构，地下1层至地上19层柱墙为型钢混凝土组合结构，每层62根H形、十字形钢骨柱（图1），型钢总用钢量为2500t。     

诱导缝在地下室外墙防渗漏控制中的应用

为控制超长无缝地下室结构外墙开裂,通过在混凝土外墙中设置诱导缝,可以有效解决地下室外墙开裂而导致的渗漏问题,文中介绍其工作原理及优点、施工措施等,供设计及施工参考。     

渐变超高大悬挑结构施工的时变性研究

针对某口岸综合楼主体结构"逐层渐变、多层悬挑、超高"等特点,建立结构与支撑体系的统一模型,并利用有限元的"基于时间属性"技术,模拟了结构与支撑体系共同作用的时变过程,同时通过对比施工监测数据,揭示了支撑体系内力变化规律,解决了常规脚手架计算方法无法适用于本工程的技术难题,为现场的安全可靠施工提供了理论依据。     

双层砂井地基大变形固结方程差分解

基于砂井地基轴对称大变形固结控制方程,综合考虑双层砂井地基软土的压缩性与渗透性非线性幂函数变化、分级加荷、径向与竖向同时渗流排水、初始超静孔压几种分布模式等实际条件,采用交替方向隐式（ADI）差分法编程求解了建立的双层砂井地基大变形固结控制方程,通过算例分析验证了建立的方程与差分解法及编制程序的合理性。将本文方法应用于围海造陆工程吹填淤泥与海相沉积淤泥组成的双层砂井地基固结计算,预测的固结沉降过程较经典固结理论更接近于实测值,对双层砂井地基固结沉降过程预测进行了有益的探讨。     

深圳地区保障性住房屋面工程精品策划

保障性住房屋面工程防水层质量好坏直接影响到住宅的功能和居住环境,本文根据深圳地区的自然条件,对屋面防水设计、施工进行策划,使施工的屋面达到精品化的目标,且节约成本。     

The influence of data quality on urban heating demand modeling using 3D city models

3D city models are rich data sets for urban energy analyses, providing geometrical and semantic data required to estimate the energy demand of entire districts, cities and even regions. However, given the diverse availability, uncertainty and Level of Details of these data and the resources required to collect them, managing data quality is a common challenge of urban energy modeling. Knowing the influences of the different input data for different configurations and applications enables to control the result accuracy and recommend intelligent and adequate data collecting strategies, by assigning resources on the most important parameters. This paper investigates the influences of geometrical, meteorological, semantic and occupancy related data quality on the heating demand estimated by the urban energy simulation platform SimStadt, applied to the City of Ludwigsburg in Germany. A focus on a district with consumption data available at building block level allows for a critical comparison between estimated and measured energy demands. Although the quantified information presented in this paper is specific to a case study, the main trends and developed methods are transferrable to other urban energy analysis studies based on 3D city models.     

A two-level topological model for 3D features in CityGML

CityGML, as the standard for the representation and exchange of 3D city models, contains rich information in terms of geometry, semantics, topology and appearance. With respect to topology, CityGML adopts the XLink approach to represent topological relationships between different geometric aggregates or thematic features; however, it is limited to shared objects. This paper proposes a two-level model for representing 3D topological relationships in CityGML: high-level (semantic-level) topology between semantic features and low-level (geometric-level) topology between geometric primitives. Five topological relationships are adopted in this model: touch, in, equal, overlap and disjoint. The semantic-level topology is derived from the geometric-level topology on the basis of the shared geometric primitives. To maintain the 3D topology, topological consistency rules are presented. An Application Domain Extension, called TopoADE, is proposed for the implementation of the topological model. The TopoADE consists of three modules: Topology, Feature and Geometry. Finally, 3D city models with LoD1 to LoD4 are used to test this model. Experimentation on those data sets indicates a validation of the proposed topological model in CityGML.     

广东台山核电站内安全壳穹顶施工阶段受力性能及稳定性分析

以广东台山核电站工程为研究背景，建立安全壳穹顶的复杂实体有限元分析模型，合理简化边界条件，以整体模型能量误差评估网格精度。该工程穹顶跨度近50 m、内衬6 mm厚的钢板。针对施工时变结构特点，考虑混凝土弹性模量随龄期变化的影响，采用重叠单元和生死单元技术，分析大跨度穹顶在混凝土浇筑成形整个施工过程中的结构变形和应力，并考虑初始几何缺陷和材料弹塑性的影响，分析施工关键阶段结构在新浇筑混凝土自质量及施工活荷载作用下的稳定承载力。结果表明：施工时变全过程分析结果与整体一次成型建模分析的结果差异显著，前者分析的结构最大挠度为3.2 mm，而后者分析的仅为1.2 mm；施工过程中结构稳定安全系数不小于3.4，满足要求。