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1.
Levels of spatial segregation in Western European cities are persistent over space and time. To demonstrate the degree or appearance of spatial segregation, most studies on urban residential patterns still rely on fixed spatial units, aspatial measures and single scales. However, a spatial or temporal comparison of patterns and levels of segregation based on such units or metrics is not without problems. To that end, this paper takes an explicit geographic approach and considers individualized neighborhoods using EquiPop-software, allowing various scales. Using the k-nearest neighbors for all individuals increases international comparability and facilitates interpretation, so far often hampered in segregation research. This multiscalar, multigroup comparative approach on ethnic urban geographies – using Belgium as a case study – provides an empirical illustration of a valuable method and tool applicable in segregation research, thereby furthering the comprehension of the increasingly diverse urban geographies and building on emerging work in the US, Europe and beyond. 相似文献
2.
One feature discovered in the study of complex networks is community structure, in which vertices are gathered into several groups where more edges exist within groups than between groups. Many approaches have been developed for identifying communities; these approaches essentially segment networks based on topological structure or the attribute similarity of vertices, while few approaches consider the spatial character of the networks. Many complex networks are spatially constrained such that the vertices and edges are embedded in space. In geographical space, nearer objects are more related than distant objects. Thus, the relations among vertices are defined not only by the links connecting them but also by the distance between them. In this article, we propose a geo-distance-based method of detecting communities in spatially constrained networks to identify communities that are both highly topologically connected and spatially clustered. The algorithm is based on the fast modularity maximisation (CNM) algorithm. First, we modify the modularity to geo-modularity Qgeo by introducing an edge weight that is the inverse of the geographic distance to the power of n. Then, we propose the concept of a spatial clustering coefficient as a measure of clustering of the network to determine the power value n of the distance. The algorithm is tested with China air transport network and BrightKite social network data-sets. The segmentation of the China air transport network is similar to the seven economic regions of China. The segmentation of the BrightKite social network shows the regionality of social groups and identifies the dynamic social groups that reflect users’ location changes. The algorithm is useful in exploring the interaction and clustering properties of geographical phenomena and providing timely location-based services for a group of people. 相似文献
3.
Integrating social network data into GISystems 总被引：1，自引：0，他引：1
Clio Andris 《International journal of geographical information science》2016,30(10):2009-2031
Today, online social media outlets provide new and plentiful sources of data on social networks (SNs) and location-based social networks (LBSNs), i.e., geolocated evidence of connections between individuals. While SNs have been used to show how the magnitude of social connectivity decreases with distance, there are few examples of how to include SNs as layers in a GISystem. If SNs, and thus, interpersonal relationships, could be analyzed in a geographic information system (GIS) setting, we could better model how humans socialize, share information, and form social groups within the complex geographic landscape.
Our goal is to facilitate a guide for analyzing SNs (as derived from online social media, telecommunications, surveys, etc.) within geographic space by combining the mature fields of social network analysis (SNA) and GISystems. First, we describe why modeling socialization in geographic space is essential for understanding human behavior. We then outline best practices and techniques for embedding SN nodes and edges in GISystems by introducing terms like ‘social flow’ and ‘anthrospace’, and categorizations for data and spatial aggregation types. Finally, we explore case study vignettes of SNA within GISystems from diverse regions located in Bolivia, China, Côte d’Ivoire, Singapore, the United Kingdom, and the United States, using concepts such as geolocated dyads, ego–alter relationships, node feature roles, modularity, and network transitivity. 相似文献
4.
Luliang Tang Xia Zhang Fei Sun Xue Yang Qingquan Li 《International journal of geographical information science》2016,30(9):1717-1737
ABSTRACTKernel Density Estimation (KDE) is an important approach to analyse spatial distribution of point features and linear features over 2-D planar space. Some network-based KDE methods have been developed in recent years, which focus on estimating density distribution of point events over 1-D network space. However, the existing KDE methods are not appropriate for analysing the distribution characteristics of certain kind of features or events, such as traffic jams, queue at intersections and taxi carrying passenger events. These events occur and distribute in 1-D road network space, and present a continuous linear distribution along network. This paper presents a novel Network Kernel Density Estimation method for Linear features (NKDE-L) to analyse the space–time distribution characteristics of linear features over 1-D network space. We first analyse the density distribution of each linear feature along networks, then estimate the density distribution for the whole network space in terms of the network distance and network topology. In the case study, we apply the NKDE-L to analyse the space–time dynamics of taxis’ pick-up events, with real road network and taxi trace data in Wuhan. Taxis’ pick-up events are defined and extracted as linear events (LE) in this paper. We first conduct a space–time statistics of pick-up LE in different temporal granularities. Then we analyse the space–time density distribution of the pick-up events in the road network using the NKDE-L, and uncover some dynamic patterns of people’s activities and traffic condition. In addition, we compare the NKDE-L with quadrat method and planar KDE. The comparison results prove the advantages of the NKDE-L in analysing spatial distribution patterns of linear features in network space. 相似文献
5.
Bin Jiang 《International journal of geographical information science》2013,27(7):823-837
A city can be topologically represented as a connectivity graph, consisting of nodes representing individual spaces and links if the corresponding spaces are intersected. It turns out in the space syntax literature that some defined topological metrics can capture human movement rates in individual spaces. In other words, the topological metrics are significantly correlated to human movement rates, and individual spaces can be ranked by the metrics for predicting human movement. However, this correlation has never been well justified. In this paper, we study the same issue by applying the weighted PageRank algorithm to the connectivity graph or space–space topology for ranking the individual spaces, and find surprisingly that: (1) the PageRank scores are better correlated to human movement rates than the space syntax metrics, and (2) the underlying space–space topology demonstrates small world and scale free properties. The findings provide a novel justification as to why space syntax, or topological analysis in general, can be used to predict human movement. We further conjecture that this kind of analysis is no more than predicting a drunkard's walking on a small world and scale free network. 相似文献
6.
基于世界城市网络研究路径和沿海湾区经济发展背景,以浙江省县市（区）级行政单位为研究对象,将19家国内银行在各行政单元的数量和级别分布作为基础数据,使用链锁模型、社会网络分析等研究方法,对浙江省城镇网络空间的结构特征进行分析。研究表明：一是浙江省金融机构分布层级明显,与城市行政等级及经济地位密切相关;二是除杭州金融中心作用凸显之外,宁波、台州和温州等沿海城市也成为金融机构网络中的重要空间节点;三是研究区域内的政府干预、金融需求、经济协作关系以及文化差异对金融联系下的城市网络的扩张有显著的影响,金融业比重、人均GDP和行政边界则并无显著作用。 相似文献
7.
多元交通流视角下的空间级联系统比较与地理空间约束 总被引：10，自引：3，他引：7
交通运输联系是区域空间级联系统与城市体系结构研究的重要视角之一,而不同交通运输方式表达的级联体系结构亦存在一定的差异。为综合研究交通运输体系刻画的空间级联系统及克服单一交通方式的局限性,基于长途汽车、高铁和航班时刻表数据,比较分析了多元交通网络的空间级联体系结构及其表达的城市网络组织体系,并进一步揭示了地理空间的约束作用。研究发现：① 每种交通运输方式适合在一定的空间尺度和行政范围内刻画和表达城市网络体系结构与城市联系,公路客运受省域行政范围约束,高铁联系具有廊道影响效应,航空运输体现全国和区域尺度较高层次的社会经济联系。② 从旅客直达视角分析,长途汽车与高铁的城际运输市场重叠最大,近年来长途汽车的运输市场受高铁影响明显。③ 地理空间是影响陆路交通运输和组织的重要约束因子,距离衰减效应明显;结合设施空间、行政空间和管理体制的作用,长途汽车和高铁运输在空间上形成分异的社区结构;航空运输由于具有超空间连接特性,既不遵循距离衰减规律,社区结构也并不明显。 相似文献
8.
An exploration of spatial dispersion, pattern, and association of socio-economic functional units in an urban system 总被引：2，自引：0，他引：2
Hypotheses based on a set of socio-economic, cultural, and political functional units are examined. The geographic techniques employed in the study include spatial mean, standard distance, standard deviational ellipse, nearest neighbor analysis, and spatial analysis on a network: cross K function and network cross K function. The study not only explores the spatial pattern, distribution, and association of key socio-economic, cultural, and political units which could reveal internal structures and activities of an urban system, but also demonstrates a number of operational procedures that permit applications of traditional and advanced spatial analysis approaches in the study of real urban systems. 相似文献
9.
中国入境游客多城市旅游空间网络结构 总被引：5，自引：4，他引：1
借鉴社会网络分析技术和方法,综合运用GIS空间分析和数理统计等方法,分析了中国入境游客多城市旅游卒闻网络结构特征。结果显示：①入境游客多城市旅游空间网络共有46个节点,节点分布呈现“东南密、西北疏”的空间格局;②旅游网络中每个城市节点平均与2．96个节点具有旅游流联系,节点体系共分4个等级,等级越高,节点数量越小,传统热点城市和区域中心城市在中心性和结构洞指标方面表现好,在旅游网络中占有重要地位;③整体旅游网络密度很低,网络功能发育不完善,且均在较大的不均衡性,网络核心节点对边缘节点的入境旅游辐射效应很弱;④旅游网络共存在9个派系,区位交通、旅游资源、经济联系是派系形成的重要驱动力,城市空间距离对派系形成影响作用极小。基于旅游流联系的角度,构建以城市为节点的大尺度入境旅游空间网络结构并进行深入分析,具有理论意义和实践指导意义。 相似文献
10.
随着当代社会表现出日益凸显的流动性特征,旅游流在旅游地域系统的要素关联和空间组织中发挥重要作用。旅游体验会对旅游者的空间行为造成影响,产生游中和游后差异性的旅游流网络,为区域旅游流网络结构的重组和优化提供了新的研究视角。以黄山市为研究案例地,运用社会网络分析方法,对游中和游后的旅游流网络结构进行比较研究。研究发现：（1）在旅游流网络结构方面,游中和游后的旅游流网络均存在明显的“核心-边缘”结构,游后的旅游流空间网络规模及范围较游中发生了显著变化,旅游者倾向于对更大空间范围内的邻近节点进行组合游览;（2）在旅游流节点功能方面,核心节点在游中和游后均发挥重要的辐射和集聚功能,游后旅游流节点功能整体提高,部分具有鲜明地方文化特色的节点成为游后旅游流网络的关键节点;（3）在空间组织重组和优化方面,进一步增强区域内部核心旅游节点的旅游流集散功能,并在更大空间范围内形成空间组织的良性互动与合作,是未来区域旅游流网络结构发展和调整的总体趋势。在此基础上,从理论和实践层面对相关结论展开讨论,并分别从空间格局、线路组织和交通体系三个方面,对黄山市旅游网络结构合理优化提出对策建议。 相似文献
11.
Binbin Lu Martin Charlton Paul Harris A. Stewart Fotheringham 《International journal of geographical information science》2014,28(4):660-681
Geographically weighted regression (GWR) is an important local technique for exploring spatial heterogeneity in data relationships. In fitting with Tobler’s first law of geography, each local regression of GWR is estimated with data whose influence decays with distance, distances that are commonly defined as straight line or Euclidean. However, the complexity of our real world ensures that the scope of possible distance metrics is far larger than the traditional Euclidean choice. Thus in this article, the GWR model is investigated by applying it with alternative, non-Euclidean distance (non-ED) metrics. Here we use as a case study, a London house price data set coupled with hedonic independent variables, where GWR models are calibrated with Euclidean distance (ED), road network distance and travel time metrics. The results indicate that GWR calibrated with a non-Euclidean metric can not only improve model fit, but also provide additional and useful insights into the nature of varying relationships within the house price data set. 相似文献
12.
基于中国高铁城市间列车流动数据构建高铁城市网络,利用脆弱性视角对中国高铁城市网络韧性进行研究,并探讨了新型冠状病毒肺炎疫情背景下武汉和湖北封城状态的网络韧性及城市响应,主要结论为：① 中国高铁城市网络发育程度有待提高,城市网络发展水平区域差异性和层级性特征明显。② 城市网络核心节点地位突出,控制能力强,关联效应显著,城市网络具有较强的适应和恢复能力,但网络韧性受关键节点影响显著。③ 蓄意攻击相比随机攻击能显著降低城市网络韧性,但在核心网络未遭受严重打击状态下,整体网络仍能保持较高的运转效率。④ 中国高铁城市核心网络保留了城市网络的主要运行特征,东高西低的网络发育特征明显,京广和京沪高铁是核心网络中交往最为频繁的通道。⑤ 武汉和湖北封城对中国高铁城市网络韧性总体影响较小,但对城市节点影响明显,总体上受到城市行政等级、交通运输干线和地理空间距离等因素影响,区域封锁状态下随着核心-边缘结构的调整,城市将提升自我核心度以弥补封锁区域核心地位的缺位。 相似文献
13.
网络演化是演化经济地理学研究的重要内容和新近热点之一。在当前的理论探讨中主要强调路径依赖和惯例对网络演化的强化作用,对于信任这个关键要素缺乏深入探讨。本文通过深度访谈和问卷调查相结合的方法,对比金融危机前后广东省纺织服装行业生产网络的空间结构,揭示信任与生产网络演化之间的互动机制。研究发现:信任是维系生产网络稳定性的基本要素之一,信任的强弱程度主要受合作类型(市场关系)、地理接近(空间关系)和社会文化接近根植性(社会关系)等因素影响。金融危机作为一种负面外部冲击,重构了广东省服装行业的生产网络。在这个过程中,较强信任关系的网络连结(潮汕地区)得以保留,并在危机过后进一步强化;而部分较弱信任关系的网络连结(珠三角地区)发生断裂,且在经济回暖之后被潮汕地区的网络所取代。 相似文献
14.
中国沿海三大城市群城市空间网络拓展分析——以综合交通信息网络为例 总被引：10，自引：7，他引：3
在以“空间流”为逻辑的区域空间组织下,借由城际交通与信息网络的全面发展改变着社会经济空间结构的深度与广度,由此产生的“时空压缩”效应大幅度增强城市信息联系,促使现代城市在“空间流”的作用下不断扩展城市网络空间。针对中国在城镇化发展过程中出现的沿海三大城市群：长三角、京津冀以及珠三角城市群,对其进行城市空间网络分析,结果表明：① 公路运输、普通列车、高速列车、信息网络在一定程度上把相互连接的城市转变成为城市空间对外拓展的网络节点,拉近节点城市与周边城市的时空距离,带动城市群区域信息“网络化”结构的形成;② 长三角城市群城市空间网络主要以上海（沪）、南京（宁）核心节点城市构成,北翼网络化程度较高于南翼线性联系程度,其区域联系密度以“沪-宁”“沪-杭”沿线向两侧递减;其城市群城市网络拓展流向主要是以上海→湖州、上海→宁波、上海→泰州、南京→扬州、南京→镇江、南京→无锡、南京→苏州、南京→上海、杭州→宁波等城市流向,呈现典型多中心结构;③ 京津冀城市群城市空间网络主要以北京、天津为核心向外辐射,形成了以廊坊、沧州、承德、张家口等次级城市网络连线。其城市群城市间网络的拓展流向主要是以北京→天津、北京→石家庄、北京→秦皇岛、北京→廊坊、天津→秦皇岛、天津→石家庄等城市流向,呈现典型的双核心结构,这些城市彼此之间呈现复杂网状联系特征,其中,北京-天津-石家庄围成度中心网络的核心圈层,度中心值较低的其他10个城市节点组成外围低密度圈层;④ 珠三角城市群城市空间网络主要以广州、深圳、珠海为核心向外辐射,形成了以佛山、惠州、江门等次级城市网络连线。其城市群城市网络拓展方向主要以广州→深圳、广州→肇庆、广州→东莞、深圳→广州、深圳→东莞、珠海→东莞等城市流向。其中,广东、深圳处于网络的绝对中心位置,广东-深圳-东莞-佛山围成度中心网络的核心圈层,度中心值较低的其他5个城市节点组成外围低密度圈层,多核心网络结构特征显著。 相似文献
15.
基于“流空间”视角研究电子商务快递物流网络,以中国智能物流骨干网络大数据作为物流“流”数据,综合社会网络分析法和GIS空间分析,以珠三角城市群为案例探究电商快递物流网络空间结构特征,并利用QAP回归方法探究影响网络形成的因素。结果表明:珠三角电商快递物流网络结构存在空间非均衡特征,联系方向偏中心指向,中东部县区间联系更为密切,形成“穗莞深”物流轴线。东莞市,广州市增城区、荔湾区、白云区,深圳市南山区、龙岗区等为主要的快递物流对外辐射节点;江门市新会区、台山市,惠州市惠城区、惠东县等为主要的快递物流接收节点。珠三角城市群电商快递物流网络形成主要受人均可支配收入和社会消费品零售总额影响,人口因素已不构成其发展优势;网络形成在一定程度上克服了距离因素的负作用力。 相似文献
16.
武汉都市圈城际联系通达性的测度与分析 总被引：9，自引：2，他引：7
空间- 距离- 通达性已经成为城市区域一体化联系与发展的先决条件。当前都市圈城际联 系发展与交通网络建设存在明显的不同步现象, 矛盾解决的关键是优化其路网通达性空间格局。 以武汉都市圈为实证对象, 构建最短距离矩阵, 引入时间、空间通达性模型, 建立高等级路网发育 评价指标体系, 从节点体系与网络体系两个角度, 定量分析武汉都市圈城际通达性变化及其空间 格局, 揭示出: 圈域城镇( 节点) 体系通达性空间差异明显, 与城市自身交通区位、经济发展水平密 切相关, 其空间格局与城镇等级规模呈共轭协同关系, 不同空间等级节点形成以武汉为中心的同 心圈层与“轴—辐”网络空间格局; 快速交通干道网络( 高速公路、铁路等) 是城市通达性空间演变 的重要推动力, 使其空间收敛减速, 形成显著的带状分异格局, 初步形成沪蓉东西向、京珠南北向 的两大城市经济联系交通走廊; 圈域城际交通干网发育程度偏低, 处于回路网络水平, 高等级路 网扩展潜力巨大。 相似文献
17.
构建层次分明、结构合理的科技合作网络对于推动京津冀协同创新具有非常重要的作用。本文从基于知识创新的科研合作网络和基于技术创新的技术合作网络的角度,使用合作论文和合作专利数据,采用社会网络分析法对2013—2018年京津冀地区地级及以上城市之间科技合作网络的演变特征进行了分析,并基于半参数估计和面板计量模型实证检验了影响京津冀78个城市对之间科技合作的主要因素。主要结论为：① 京津冀科研合作网络快速成长,呈现北京与天津双核引领,以京津为主轴、京保石为次轴的空间结构。② 京津冀逐渐形成了以北京为主中心,天津、石家庄为次中心,廊坊、保定、沧州为三级枢纽,其他城市为节点的技术合作网络结构。③ 空间距离越近的城市之间越容易产生科技合作,高铁开通带来的时空距离压缩可以减弱科技合作的空间衰减系数;相对于科研合作,技术合作对于空间距离更为敏感;技术邻近性是促进城市间科技合作的主要驱动因子,尤其是对技术合作的促进效应更为明显;经济发展差距越小的城市之间相对容易产生技术合作。 相似文献
18.
中国主体功能区空间结构的多尺度解析 总被引：1，自引：1，他引：0
The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of urbanization zones,agricultural development zones and ecological security zones as the basic parameter,this paper explores the spatial structures of major function zoning at different scales using spatial statistics,spatial modeling and landscape metrics methods.The results show:First,major function zones have spatial gradient structures,which are prominently represented by latitudinal and longitudinal gradients,a coastal distance gradient,and an eastern-central-western gradient.Second,the pole-axis system structure and core-periphery structure exist at provincial scales.The general principle of the pole-axis structure is that as one moves along the distance axis,the proportion of urbanization zones decreases and the proportion of ecological security zones increases.This also means that the proportion of different function zones has a ring-shaped spatial differentiation principle with distance from the core.Third,there is a spatial mosaic structure at the city and county scale.This spatial mosaic structure has features of both spatial heterogeneity,such as agglomeration and dispersion,as well as of mutual,adjacent topological correlation and spatial proximity.The results of this study contribute to scientific knowledge on major function zones and the principles of spatial organization,and it acts as an important reference for China’s integrated geographical zoning. 相似文献
19.
Giorgos Mountrakis 《International journal of geographical information science》2013,27(11):1389-1412
Moose–vehicle collisions (MVCs) pose a serious safety and environmental concern in many regions of Europe and North America. For example, in the state of Vermont, one‐third of all reported MVCs resulted in motorist injury or fatality while collisions have increased from two in 1982 to 164 in 2002. Our work used a MVC dataset from 1983 to 1999 in the Northeastern Highlands of Vermont (four major roads) to perform space, time and spatiotemporal analyses and guide future mitigation strategies. An adapted kernel density estimator was implemented for exploratory analyses to detect high density collision hotspots on roads. The kernel in space showed seven major density peaks which varied in magnitude and spread between roads. The kernel estimator in time for all roads showed an exponentially increasing trend with annual periodicity and a seasonal cyclic component, where the majority of collisions occurred from May to October. Spatiotemporal kernel estimation exhibited discontinuous density hotspots in time and space suggesting changing animal movement patterns across roads. We used an adapted Ripley's K‐function to test the hypothesis that MVCs clustering occurred at multiple scales in space, in time and in space–time combined. Statistically significant spatial clustering was evident on all roads at spatial scales from 2 to 10 km. A more consistent clustering in time occurred on all roads at a scale distance of 5 years. Similar to the kernel estimation, annual periodicity was also evident. Positive space–time clustering was present at small spatial (5 km) and temporal scales (2 years) indicating that where MVCs occur is also influenced by when they occur. In retrospect, using multiple road lengths, and the combined kernel estimation and Ripley's K‐function in time and space, provided a powerful methodology to study varying spatiotemporal patterns of wildlife collisions along roads. This can greatly assist transportation planners in identifying optimal mitigation strategies along specific roads, such as deciding on location and spatial length for permanent and expensive measures (e.g. crossing structures and associated fencing) versus less permanent and inexpensive structures (e.g. wildlife signage and reduced speed limits). 相似文献
20.
基于Ripley’s K函数的南京市ATM网点空间分布模式研究 总被引：1，自引：0，他引：1
运用Ripley’s K函数的相关理论,以南京市ATM网点为研究对象,分别从平面与网络空间两种视角,在中心城区范围与主城区范围两种空间尺度上,通过单变量