基于空间句法的城市道路结构与地价关系研究

本文通过阐述土地价格的特殊性,在分析影响城市土地价格的主要因素的基础上,提出城市道路结构与城市地价关系密切,可据此进行城市地价评估预测。本文将进行城市形态分析的方法———空间句法,集成于GIS体系中,在Arcview平台下运行Axwoman模型,计算出各形态变量分析道路结构,寻求与地价之间的具体关系,并以济南为例,验证中心城区主干道与地价之间的关系,并对空间句法中不够完善的地方进行了改进。     

利用可视引导的Agent模拟城市人流运动

以视域引导行为准则为理论基础,以智能体（Agent）模拟为技术,在城市开空间中计算各点的视域参数,智能体根据视域参数选择运动方向,形成城市人流运动系统,来描述、模拟和预测城市空间中的人流运动及其相应的设施分布。     

车载激光点云道路场景可视域快速计算与应用

传统的可视域分析方法需借助高精度三维模型,而目前三维模型构建的自动化水平、精度和完整度等很难满足道路环境可视域分析的要求。车载激光扫描系统可以高速度、高密度、高精度地获取道路及两侧地物的位置和属性信息(如反射强度、回波波形等),为大规模道路场景可视域计算与分析提供了一种全新的技术手段。借助深度缓存算法,提出了一种基于三维激光点云数据的可视域快速、稳健计算方法。该方法在典型道路地物要素提取的基础上,动态构建视场空间索引,实现了道路场景中任意位置可视域的快速、稳健估计,可广泛应用于交通标志牌遮挡分析、路灯有效照明区域计算和建筑物可视绿地面积估计等,为基础设施科学安置及运行健康状况监测、城市形态分析与城市规划等提供科学的辅助决策。     

无障碍设施空间布局核密度热点探测和空间自相关分析——以北京市核心区室外公共空间为例

城市无障碍设施在区域空间中往往呈现聚集分布的特征，通常利用核密度估计方法分析总体空间分布形态，研究区域空间分布的数量差异，探测分布热点；同时通过分析无障碍设施空间自相关性特征，反映无障碍设施服务的聚集特点。将空间分析方法引入到无障碍环境评估当中，可以优化无障碍环境发展空间。结果表明，北京市核心区无障碍设施总体呈现出“多核分布”的态势。无障碍设施的总体分布存在空间差异性，局部无障碍设施空间分布存在聚集特性。     

城市因素对COVID-19疫情的影响——以武汉市为例

新型冠状病毒肺炎(coronavirus disease 2019,COVID-19)疫情是一次重大的突发公共卫生事件,深入研究城市空间因素对疫情发展的影响对于未来城市安全具有重要意义。武汉市是遭受COVID-19疫情影响最为严重的城市,以武汉市三环内的中心城区作为研究区域,基于COVID-19疫情的新浪微博求助数据,揭示了COVID-19疫情在城市中的空间分布格局及其对不同区域的影响。在此基础上,根据疫情的主要传播途径及相关影响因素,选取社会人口、城市形态、城市设施、城市功能4项指标进行了验证。通过将研究区域进行网格化处理,运用地理加权回归模型对这些因素的效应、空间异质性以及影响范围进行分析,解释并反演出疫情在武汉城市空间中发生、传播、扩散的实际情况和作用机制。结果显示,三甲医院密度、商业密度、地铁站点密度、建设规模、老龄化、土地混合使用对疫情有显著影响。对城市空间因素的分析和验证有利于在未来的突发性公共安全危机中采取有效的城市规划和建筑设计应对,帮助城市决策者制定科学合理的防治策略,提前规避或减小对脆弱性区域和群体的冲击。     

地籍学

OU0051103基于空间句法的城市道路结构与地价关系 研究=N止F比妞肠佣OFT触OTYR倪目别”叼比代.阅THE L』旧州二BA，目..THES，CE匀旧加/段瑞兰，郑新奇(山 东师范大学人口资源与环境学院)//测绘科学一2004，29 (5).一76~79 通过阐述土地价格的特殊性，在分析影响城市土地价 格的主要因素的基础上，提出城市道路结构与城市地价关 系密切，可据此进行城市地价评估预测。将进行城市形态 分析的方法—空间句法，集成于GIS体系中，在ARC- VIEW平台下运行AXWOMAN模型，计算出各形态变量分析 道路结构，寻求与地价之间的具体关系，…     

六盘山地区医疗设施空间分布及可达性研究

针对医疗设施的分布情况会直接影响就医的便捷程度问题,该文以六盘山地区医疗设施为研究对象,采用核密度函数分析法和最短距离计算法,对六盘山地区的医疗设施空间分布特征及可达性进行剖析,并分析其影响因素.结果表明区域内不同级别的医疗设施多集聚分布在兰州市区和西宁市区,在临夏市、定西市、白银市、固原市、庆阳市、天水市等城市主城区形成次级集聚中心.区域内医疗设施可达性水平差异显著,存在城市主城区相对边界地区医疗设施可达性较好的特点.     

基于城市形态学原理的面状地物层次索引方法

城市形态取决于城市规模、地形、城市用地功能组织和道路网结构等因素,其基础骨架是交通轴线和水系轴线。本文基于城市形态学基本原理,依据道路、水系等自然要素将地图空间划分为Enclave、Block、Superblock和Neighbourhood四个层次,在此基础之上,提出了一种新的GIS空间层次索引方法,并扩展了现有空间索引分类框架。不难发现,基于自然网格的空间划分方式不仅符合人的认知,同时有效地避免了地物跨网格分布的情况,通过实验证明索引记录的冗余对查询速度具有直接而显著的影响。     

基于空间句法的广元市城市形态演变研究

以山地河谷背景下的广元市中心城区为研究对象,基于线段模型对3个时期的城市形态进行空间句法分析。研究表明,广元市中心城区各组团中心性的变化体现其空间发展方向,并向"带状的多中心组团式"布局模式演变;城市网络化特征先弱后强,前景网络"两横两纵"的结构特征明显。受破碎与分散的城市形态影响,城市空间的连续性不强,且西部组团长期缺乏活力。     

顾及属性特征的城市设施热点识别方法

研究城市设施的热点分布对把握当前城市形态具有重要意义。传统的设施热点识别方法容易忽略设施的特征尺度且多以区域识别为主,缺少精准化提取设施热点的方法体系。针对上述问题,本文提出了一种顾及属性特征的设施热点识别方法,并以北京市住宅设施为例进行了试验分析。首先将设施的属性值作为权重,进行加权核密度估计生成密度值表面,利用极值点探测模型提取极值点;然后采用Getis-Ord G_i^*统计进行空间自相关分析,生成具有显著统计学意义的热点区域,筛选极值点得到热点。结果表明,该方法能够准确有效地识别设施热点并进行合理的等级划分,为城市设施空间布局研究提供多样化视角。     

基于3DGIS的城市规划可视性分析模型研究

视觉效果是城市规划需要考虑的重要要素之一.基于3 DGIS的计算机技术可以用于定量分析城市三维景观空间的可视性.本文介绍了可视性分析应用于城市规划的流程,提出了针对地形和建筑物可视性分析的数学几何模型.在地形可视性分析模型中,采用了一种结合水平投影和高程插值计算的方法判断地形上两点之间的通视性;在建筑物可视性分析中,采...     

Overcoming challenges in developing more usable pedestrian navigation systems

This article presents an overview of a research project focusing on improving the usability of pedestrian navigation systems by following a User-Centered Design (UCD) approach. One of the main problems with those systems is how to adequately support and enhance the spatial interactions of a traveler to new urban areas, which is crucial for successful self-orienting and wayfinding. The methodology employed allows for conceptualizing, implementing and evaluating research prototypes that aim to satisfy the special user requirements. Outlined in this article are the techniques designed and integrated in the developed prototype, the methods used for their evaluation through field-based studies and the challenges encountered during this process. New techniques with a measurable impact on the effectiveness, efficiency and satisfaction of navigation were tested and found to dramatically enhance the sense of personal geo-identification in new places. Examples of those techniques are landmark visibility indication, multi-path routing based on time availability, multi-perspective landmark photos and reverse overview + detail maps. Overall, the outcomes of this research verify the capacity of UCD to help overcoming current usability issues with pedestrian navigation systems. By demonstrating an effective UCD methodology and discussing the lessons learned, we intend to aid the development of next generation navigation appliances.     

数学形态学在GIS空间分析中的应用

讨论了数学形态学在基于栅格数据结构的地理信息系统（ＧＩＳ）空间分析中的广泛应用。提出了基于形态变换的ＧＩＳ空间操作（图层叠置、缓冲区建立、邻城分析和图元量算）方法，网络最短路径的形态学算法，应用灰度级形态学解求通视图的新思路。     

Crowd sensing and spatiotemporal analysis in urban open space using multi-viewpoint geotagged videos

Increasing concern for urban public safety has motivated the deployment of a large number of surveillance cameras in open spaces such as city squares, stations, and shopping malls. The efficient detection of crowd dynamics in urban open spaces using multi-viewpoint surveillance videos continues to be a fundamental problem in the field of urban security. The use of existing methods for extracting features from video images has resulted in significant progress in single-camera image space. However, surveillance videos are geotagged videos with location information, and few studies have fully exploited the spatial semantics of these videos. In this study, multi-viewpoint videos in geographic space are used to fuse object trajectories for crowd sensing and spatiotemporal analysis. The YOLOv3-DeepSORT model is used to detect a pedestrian and extract the corresponding image coordinates, combine spatial semantics (such as the positions of the pedestrian in the field of view of the camera) to build a projection transformation matrix and map the object recorded by a single camera to geographic space. Trajectories from multi-viewpoint videos are fused based on the features of location, time, and directions to generate a complete pedestrian trajectory. Then, crowd spatial pattern analysis, density estimation, and motion trend analysis are performed. Experimental results demonstrate that the proposed method can be used to identify crowd dynamics and analyze the corresponding spatiotemporal pattern in an urban open space from a global perspective, providing a means of intelligent spatiotemporal analysis of geotagged videos.     

Geometric methods for estimating representative sidewalk widths applied to Vienna’s streetscape surfaces database

Space, and in particular public space for movement and leisure, is a valuable and scarce resource, especially in today’s growing urban centres. The distribution and absolute amount of urban space—especially the provision of sufficient pedestrian areas, such as sidewalks—is considered crucial for shaping living and mobility options as well as transport choices. Ubiquitous urban data collection and today’s IT capabilities offer new possibilities for providing a relation-preserving overview and for keeping track of infrastructure changes. This paper presents three novel methods for estimating representative sidewalk widths and applies them to the official Viennese streetscape surface database. The first two methods use individual pedestrian area polygons and their geometrical representations of minimum circumscribing and maximum inscribing circles to derive a representative width of these individual surfaces. The third method utilizes aggregated pedestrian areas within the buffered street axis and results in a representative width for the corresponding road axis segment. Results are displayed as city-wide means in a 500 by 500 m grid and spatial autocorrelation based on Moran’s I is studied. We also compare the results between methods as well as to previous research, existing databases and guideline requirements on sidewalk widths. Finally, we discuss possible applications of these methods for monitoring and regression analysis and suggest future methodological improvements for increased accuracy.     

Simulated impacts of 3D urban morphology on urban transportation in megacities: case study in Beijing

Urban morphology and morphology change and their impacts on urban transportation have been studied extensively in planar urban space. The essential feature of urban space, however, is its three-dimensionality (3D), and few studies have been conducted from a 3D perspective, overly limiting the accuracy of studies on the relationships between urban morphology and transportation. The aim of this paper is to simulate the impacts of 3D urban morphologies on urban transportation under the Digital Earth framework. On the basis of the principle that population distribution and movement are largely confined by 3D urban morphologies, which affect transportation, high spatial resolution remote sensing imagery and a thematic vector data-set were used to extract urban morphology and transportation-related variables. With a combination of three research methods – factor analysis, spatial regression analysis and Euclidean allocation – we provide an effective method to construct a simulation model. The paper indicates three general results. First, building capacity in the urban space has the most significant impact on traffic condition. Second, obvious urban space otherness, reflecting both use density characteristics and functional characteristics of urban space, mostly results in heavier traffic flow pressure. Third, no single morphology density indicator or single urban structure indicator can reflect its contribution to the pressure of traffic flow directly, but a combination of these different indicators has the ability to do so.     

一种用于三维城市建筑物的可视域分析算法

作为3DGIS的一种空间分析方法,可视域分析在城市规划、军事和考古等方面有着广泛的应用,其实现则主要基于点对点的通视分析。本文基于多数城市建筑物外形相对规则的特点,提取建筑物的最小矩形包围盒,基于视点位置得到每个模型的可视面角点和视点构成锥体,通过计算其他锥体底面在某一锥体底面所在平面上的投影区和该锥体底面多边形的差集得到每个模型的可视面,避免通过计算建筑物模型每个点的通视性得到建筑物的可视域,以减少计算量,提高计算效率,最后的实现效果证明了本文算法的可行性和有效性。     

Unpacking isovists: a framework for 3D spatial visibility analysis

This article explores the ways in which researchers conceptualize and visualize visibility in spatial research – using isovists and visualscapes. We review how visibility analyses have been used in spatial analysis and visualization. We dissect the geometric conceptualization of isovists, and geometric relationships between isovist origins and targets. From this, we develop an expanded typology of isovists based on geometries of visibility and the relationships between an observer and the observed. This typology differentiates panoptic isovists, constrained isovists, and targeted isovists. We apply these isovist examples to urban privacy and surveillance to ground the new conceptual framework. We conclude with a discussion surrounding future research and conceptual development needed to advance visualscapes and visibility analysis.