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1.
ABSTRACT

The increasing popularity of Location-Based Social Networks (LBSNs) and the semantic enrichment of mobility data in several contexts in the last years has led to the generation of large volumes of trajectory data. In contrast to GPS-based trajectories, LBSN and context-aware trajectories are more complex data, having several semantic textual dimensions besides space and time, which may reveal interesting mobility patterns. For instance, people may visit different places or perform different activities depending on the weather conditions. These new semantically rich data, known as multiple-aspect trajectories, pose new challenges in trajectory classification, which is the problem that we address in this paper. Existing methods for trajectory classification cannot deal with the complexity of heterogeneous data dimensions or the sequential aspect that characterizes movement. In this paper we propose MARC, an approach based on attribute embedding and Recurrent Neural Networks (RNNs) for classifying multiple-aspect trajectories, that tackles all trajectory properties: space, time, semantics, and sequence. We highlight that MARC exhibits good performance especially when trajectories are described by several textual/categorical attributes. Experiments performed over four publicly available datasets considering the Trajectory-User Linking (TUL) problem show that MARC outperformed all competitors, with respect to accuracy, precision, recall, and F1-score.  相似文献   

2.
了解城市人群移动行为和空间结构对城市规划、交通管理、应急响应等具有重要的意义。近年来,随着信息技术(ICT)的快速发展,采集大规模、长时间序列的人群移动定位大数据变得容易,为人群移动行为研究带来了新的机遇和挑战。本文首先介绍了目前用于城市人群移动行为和空间结构研究的主要数据源及其特征,并分别从人群移动行为、城市空间结构2个方面对近3年国内外相关研究进行归纳总结。目前的研究主要从移动定位大数据中挖掘人群移动模式,理解人群移动时空规律,进一步透视城市的空间结构特征;而对城市空间结构与人群移动行为影响的研究较少。未来可通过融合多源时空数据,综合研究人群移动行为与城市空间结构之间的相互作用,发展大规模群体移动行为时空分析理论和模型,进一步深入理解人群移动行为与城市空间结构的耦合关系。  相似文献   

3.
In recent years urban geographers have devoted considerable attention to the dynamics of policy mobility. After reviewing the progress achieved in this literature, in this article I offer two distinctive contributions. First, I draw on the “argumentative turn” in policy studies and related fields in order to develop an alternative conceptualization of urban policy mobility that pays greater attention to its discursive and argumentative aspects. I thus reassert the significance of democratic processes in the negotiation of urban policy. Second, I outline an alternative methodology for the study of urban policy mobility, focusing on the analysis of argumentation. I apply this methodology to historical instances of urban policy mobilities arising from a recent research project that aimed to historicize the phenomenon of the “model city,” defined as the local deployment of another city’s experience as an argumentative resource supporting particular policy claims.  相似文献   

4.
江颂  彭建  董建权  程雪雁  丹宇卓 《地理学报》2022,77(9):2249-2265
明晰城市热岛（UHI）效应相关概念内涵、厘清其定量刻画方法是有效开展UHI效应研究的重要基础。全球城市化进程使UHI效应越发普遍,相关研究数量迅速增长并出现了UHI效应的多样认知,尤其对具有空间异质性表征优势的地表城市热岛（SUHI）效应开发了多样的定量刻画方法,但目前尚缺乏对其定量刻画方法的系统梳理。因此,本文对城市热岛、城市热岛效应、地表温度和城市热环境等易混淆概念进行了辨析,总结了各类UHI典型空间位置和尺度范围。在SUHI效应定量刻画中,将SUHI范围识别方法归结为城乡温度阈值、温度等级阈值、高斯拟合参数、温度衰减突变四大类,指出当前SUHI范围识别研究侧重于对SUHI影响规模的认知。研究同时对各类范围识别方法所对应的SUHI强度表征指标进行了梳理,认为理解指标本质内涵是掌握指标间潜在差异的前提。未来研究应整合多维度数据以突破单一SUHI监测途径,发展大尺度SUHI定量刻画方法以拓展定量研究的广度,认知连通化SUHI空间形态以挖掘范围识别研究的深度。  相似文献   

5.
It is challenging to find relevant data for research and development purposes in the geospatial big data era. One long-standing problem in data discovery is locating, assimilating and utilizing the semantic context for a given query. Most research in the geospatial domain has approached this problem in one of two ways: building a domain-specific ontology manually or discovering automatically, semantic relationships using metadata and machine learning techniques. The former relies on rich expert knowledge but is static, costly and labor intensive, whereas the second is automatic and prone to noise. An emerging trend in information science takes advantage of large-scale user search histories, which are dynamic but subject to user- and crawler-generated noise. Leveraging the benefits of these three approaches and avoiding their weaknesses, a novel methodology is proposed to (1) discover vocabulary-based semantic relationships from user search histories and clickstreams, (2) refine the similarity calculation methods from existing ontologies and (3) integrate the results of ontology, metadata, user search history and clickstream analysis to better determine their semantic relationships. An accuracy assessment by domain experts for the similarity values indicates an 83% overall accuracy for the top 10 related terms over randomly selected sample queries. This research functions as an example for building vocabulary-based semantic relationships for different geographical domains to improve various aspects of data discovery, including the accuracy of the vocabulary relationships of commonly used search terms.  相似文献   

6.
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7.
城市用地与人口的异速增长和相关经验研究   总被引：16，自引：5，他引：16  
梁进社  王旻 《地理科学》2002,22(6):649-654
由于城市土地利用变化涉及的因素多，使获取动态研究研究所需的资料十分困难，所以，用少数几个主要因素定量地表达其变化就显得十分重要。从前人的成果，即以人口表示的城市位序-规模法则和建成区面积表示的位序-规模法则出发，绽绎出城市的用地规模和人口数量呈异速增长。这意味着，如果把整个城市看成是一个生命有机体，那么作为反映城市特征的城市用地规模和城市人口这两个重要变量，就是城市这个有机体的两个器官，他们的增长率是成比例的。还通过这个关系建立了城市建成区面积与市场人口和经济发展水平的数学模式。对我国部分城市的经验研究在一定程度上分别证明了这两经验关系。  相似文献   

8.
系统开展城市扩张研究，是防治城市蔓延、促进城市精明增长的重要基础。利用文献研究法总结国内外城市扩张内涵与度量的研究进展，并对发展趋势进行评述。研究表明：城市扩张度量研究备受关注，成果产出呈逐年增长之势。从代表性论文发表情况来看，“刊源集中”、“稿源集中”特征明显，中、美两国城市扩张研究成果产出量大，国内学者仍需在提升成果影响力上持续发力。城市扩张内涵界定百家争鸣，但国内外学者已形成一定的共识，即城市扩张是对特定城市发展模式下城市形态的“现实性”描述。尽管已形成了“城市用地扩张”和“城市蔓延”两大代表性研究框架，城市扩张概念内涵仍需进一步完善。城市扩张度量研究成果丰硕，但已有指标和模型多从单一的“时间”或“空间”维度表征城市扩张时序演化规律或空间格局，新数据、新理论及新方法应用有望促进城市扩张度量“时空统计模型”研究。城市扩张度量实证涉及全球、国家、流域、城市群、城市、街道等多个尺度，中国成为城市扩张度量研究的热点区域。研究呼吁重视在充分顾及区域制度与社会经济状况及城市管理需求差异前提下的城市扩张内涵界定，强化城市扩张度量时空统计模型研究，积极推进微观尺度城市扩张度量及成果应用。  相似文献   

9.
Existing urban boundaries are usually defined by government agencies for administrative, economic, and political purposes. However, it is not clear whether the boundaries truly reflect human interactions with urban space in intra- and interregional activities. Defining urban boundaries that consider socioeconomic relationships and citizen commute patterns is important for many aspects of urban and regional planning. In this paper, we describe a method to delineate urban boundaries based upon human interactions with physical space inferred from social media. Specifically, we depicted the urban boundaries of Great Britain using a mobility network of Twitter user spatial interactions, which was inferred from over 69 million geo-located tweets. We define the non-administrative anthropographic boundaries in a hierarchical fashion based on different physical movement ranges of users derived from the collective mobility patterns of Twitter users in Great Britain. The results of strongly connected urban regions in the form of communities in the network space yield geographically cohesive, nonoverlapping urban areas, which provide a clear delineation of the non-administrative anthropographic urban boundaries of Great Britain. The method was applied to both national (Great Britain) and municipal scales (the London metropolis). While our results corresponded well with the administrative boundaries, many unexpected and interesting boundaries were identified. Importantly, as the depicted urban boundaries exhibited a strong instance of spatial proximity, we employed a gravity model to understand the distance decay effects in shaping the delineated urban boundaries. The model explains how geographical distances found in the mobility patterns affect the interaction intensity among different non-administrative anthropographic urban areas, which provides new insights into human spatial interactions with urban space.  相似文献   

10.
Urban development charges (UDC) are considered relevant taxation instruments that can improve the economic sustainability of urban areas and the financial health of the respective local governments. The economic formulation and justification based on the ‘direct benefit principle,’ the ‘accountability principle,’ and the ‘proportionality principle’ requires a methodology that can be supported by a geographic information system (GIS) application. This article presents the research output of a real case study – the municipality of Aljezur, Portugal – and the fundamentals of the GIS tool that was designed. This GIS-based methodology comprises a multi-annual infrastructure capital plan and an accurate zoning map for spatial differentiation of values combining municipal-wide and site-specific approaches, following ‘pay as the urban areas grow’ perspective applied to urban development and new buildings. It requires data integration of the urban planning process with infrastructure and urban growth data in order to manage and monitor the computation of this charge over time, thereby increasing the accuracy, the objectivity and the clarity of the process. The results obtained show that this UDC-GIS application seems well adapted to small municipalities. Its possible replication and use in other contexts require adaptations derived from different urban and taxation policy options and from different legal, organizational, technological, and informational local systems.  相似文献   

11.
北京市居民居住—就业选择的协同性研究   总被引：4，自引：0，他引：4  
居民在住房市场上的迁居决策和劳动力市场上的工作迁移决策,是城市空间结构塑造和演化的重要微观因素。本文以2009 年北京市城市居住环境评价和偏好选择抽样调查问卷为基础,探讨了居民居住迁移和工作迁移决策的协同性及其异质性,结果发现：居民居住迁移决策和工作迁移决策是一个存在正向相互联系的协同决策过程,而非两个独立的决策过程;居住迁移和工作迁移决策的正向反馈强度随着微观主体住房产权、户籍和家庭就业结构等状况的不同而具有异质性,非北京市户籍、租房户和单职工家庭居民的居住迁移和工作迁移的正向相关关系要显著大于有北京市户籍、购房户和多职工家庭居民,并且不同社会经济属性的居民其居住迁移决策和工作迁移决策的影响因素也具有异质性。  相似文献   

12.
利用四期TM数据和GIS技术,分析了近20年南京城市边缘区城镇用地格局动态变化:城镇用地格局变化拐点在1994年和2000年,空间上表现出增长“热极”与“热带”;城镇用地格局变化阶段性是经济社会驱动过程演化阶段的反映,其空间特征是区域社会经济物质载体演化的体现,开发区是城镇用地增长首要来源,新市区与大学城是其增长核心和新形式,交通路网对其产生空间导向;但城镇用地增长相对处于规模扩张阶段,引致自然景观破碎化、社区“空壳”现象、大学城“圈地运动”耕地浪费严重。  相似文献   

13.
In this research, we match web-based activity diary data with daily mobility information recorded by GPS trackers for a sample of 709 residents in a 7-day survey in Beijing in 2012 to investigate activity satisfaction. Given the complications arising from the irregular time intervals of GPS-integrated diary data and the associated complex dependency structure, a direct application of standard (spatial) panel data econometric approaches is inappropriate. This study develops a multi-level temporal autoregressive modelling approach to analyse such data, which conceptualises time as continuous and examines sequential correlations via a time or space-time weights matrix. Moreover, we manage to simultaneously model individual heterogeneity through the inclusion of individual random effects, which can be treated flexibly either as independent or dependent. Bayesian Markov chain Monte Carlo (MCMC) algorithms are developed for model implementation. Positive sequential correlations and individual heterogeneity effects are both found to be statistically significant. Geographical contextual characteristics of sites where activities take place are significantly associated with daily activity satisfaction, controlling for a range of situational characteristics and individual socio-demographic attributes. Apart from the conceivable urban planning and development implications of our study, we demonstrate a novel statistical methodology for analysing semantic GPS trajectory data in general.  相似文献   

14.
Urban hierarchies are closely related to economic growth, urban planning and sustainable urban development. Due to the limited availability of reliable statistical data at fine scales, most existing studies on urban hierarchy characterization failed to capture the detailed urban spatial structure information. Previous studies have demonstrated that night time light data are correlated with many urban socio-economic indicators and hence can be used to characterize urban hierarchies. This paper presents a novel method for studying urban hierarchies from night time light data. Night time light data were first conceptualized as continuous mathematical surfaces, termed night time light surfaces. From the morphology of these surfaces the corresponding surface networks were derived. Hereafter, a night time light intensity (NTLI) graph was defined to describe the morphology of the surface network. Then, structural similarity between the night time light surfaces of any two different cities was calculated via a threshold-based maximum common induced graph searching algorithm. Finally, urban hierarchies were defined on the basis of the structural similarities between different cities. Using the 2015 annual NPP-VIIRS night time light data, the urban hierarchies of 32 major cities in China were successfully examined. The results are highly consistent with the reference urban hierarchies.  相似文献   

15.
张姗琪  甄峰  秦萧  唐佳 《地理研究》2020,39(7):1580-1591
科学准确地感知社区居民参与现状、诊断存在问题,及时广泛地了解社区居民需求与诉求,对于提升新形势下社区居民参与城市社区规划的能力与水平意义重大。借助网络和移动设备等技术手段,采取以人为主体的参与式感知方式获取数据,可实时感知和分析居民的情感、行为和所处的环境,进而提高社区居民参与的广泛性和时效性。国内外该领域的研究刚刚起步,对面向城市社区规划的参与式感知与计算尚缺乏系统深入的机理探索和方法研究。本文针对中国城市社区规划的实际需求,构建了面向城市社区规划的参与式感知与计算概念模型,提出实现参与式感知与计算的技术框架,并探讨其中涉及的具体技术研究内容。本研究将深化面向城市社区的参与式感知与计算的相关理论与方法研究,为城市社区规划的公众参与和科学评估提供新思路、新方法。  相似文献   

16.
复杂网络视角下的城市人流空间概念模型与研究框架   总被引：1，自引：0，他引：1  
罗桑扎西  甄峰  张姗琪 《地理研究》2021,40(4):1195-1208
城市内人流特征研究一直是城市地理学和城市空间研究的重要领域之一。针对已有相关研究存在仅侧重于从人口规模、密度视角分析空间分布及格局特征,而对隐藏于空间分布背后,因人流动而建立的空间交互关系关注不足的问题。本文以流空间理论、复杂网络理论、空间行为交互理论为理论基础,立足基于流、网络剖析城市内部空间中各要素间的相互作用及关系,选取人流为观测研究对象,将城市空间、人、设施、服务和地理环境等要素之间的互动关系抽象为网络,提出了基于复杂网络视角的城市人流空间概念模型。在此基础上,进一步构建了城市人流空间研究框架,即基于理论融合、数据支撑与研究方法的整合创新,以探究人流视角下的城市空间特征、功能结构、人流与建成环境时空耦合关系及流动的时空模拟预测为重点的研究内容体系,并探讨其在规划实践业务中的方法技术支撑与应用拓展。以期为未来开展实证研究提供指导,提升城市感知数据在城市空间规划及管理中的应用价值,丰富“以流定形”的理性城市规划方法体系。  相似文献   

17.
Rates of geographical mobility vary greatly, and fairly predictably, across the life course. Our analysis of special county-to-county migration tabulations of Census 2000 data discloses that, when flows are disaggregated by age, radically different patterns of net population redistribution are taking place upward and downward within the national urban hierarchy. The movements at the late-career, empty-nester, and retirement stage are the most “demographically effective” or unidirectional. The elderly fleeing large metropolitan areas have been congregating in micropolitan and rural counties with special climatic and other natural amenities. The opposite net flow is found for younger adults, who have been flocking into megametropolitan conurbations. At the midcareer stage, the net movement is from larger to medium metropolitan areas. We detail the age articulation of county-to-county migration flows with novel graphical portrayals and statistical measures. We give some thoughts on the relationship between intergenerational dependency and migration trends, and we speculate about whether the current patterns of age-articulated movement up and down the urban hierarchy will continue as the baby boom retires and the echo cohorts come of age.  相似文献   

18.
谷志莲  柴彦威 《地理科学进展》2015,34(12):1617-1627
就地养老日益受到中国城市老年人的欢迎,其中个体移动性对老年人日常生活尤具重要意义。本文从微观个体的视角出发,运用质性研究方法,选取一对空巢的高龄老年夫妇作为典型案例,对其退休以来的移动性变化与日常生活历程进行叙事分析;以期揭示移动性对老年个体生活的重要意义、移动性的变化特征与日常生活的密切关联,从而为中国城市老年服务与宜老环境建设提供科学支持。结果表明,老年个体移动性具有日常活动空间向外拓展、逐渐向社区及周边收缩、局限于家及住所附近3个阶段;随年龄增长而不断下降的身体机能与健康状况,和家庭因素共同促使老年人移动性与日常生活发生阶段性演变;个人、家庭、所在社区的资源分别构成了各阶段的核心影响因素。个体的移动性空间应成为中国城市宜老社区与环境建设以及老年规划与服务的关键命题。  相似文献   

19.
谢涤湘  李华聪 《热带地理》2013,33(2):231-236
城市更新是城市发展的一种重要方式,其关键和难点在于平衡利益相关者之间的权益博弈。在城市化快速发展时期,我国便出现了大规模的城市更新,这使得我国城市更新中的权益博弈形成了独特的模式与特征,较之于西方发达国家也更加复杂。文章认为随着我国城市更新研究的不断深入,在权益博弈研究领域取得了一定的成果,但也存在一些问题与不足,如对博弈主体间的关系研究不足、对城市更新中的“社会运动”现象研究不够,未来的研究需要综合运用多学科理论,注重典型个案的深入研究,逐步构建出合乎中国国情的城市更新权益博弈理论。  相似文献   

20.
珠江三角洲城市热岛空间分布及热岛强度研究   总被引：5，自引：0，他引：5  
进入21世纪,我国珠江三角洲地区城市化规模越来越大,研究该地区的热岛效应具有重要的现实意义。研究区21世纪初自动气象站点运行趋于稳定,数据质量好,为城市气候研究提供了数据基础。利用2000—2003年的珠江三角洲城市群自动气象站温度数据进行空间分析,统计热岛和冷岛出现的频率,总结空间分布规律,并对照土地利用类型图分析热岛区域与地表覆被的对应关系。计算每月热岛强度值,通过热岛的月际变化曲线,总结热岛的年变化规律以及昼夜差异。研究结果表明,研究区城市热岛呈现"六区两带"的空间分布格局;全年中夏季白天的热岛强度最大,并且夏季的热岛强度出现昼强夜弱的现象。  相似文献   

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