Flexible Spatial Multilevel Modeling of Neighborhood Satisfaction in Beijing     

Jing Ma  Yu Chen  Guanpeng Dong 《The Professional geographer》2018,70(1):11-21

This article develops an innovative and flexible Bayesian spatial multilevel model to examine the sociospatial variations in perceived neighborhood satisfaction, using a large-scale household satisfaction survey in Beijing. In particular, we investigate the impact of a variety of housing tenure types on neighborhood satisfaction, controlling for household and individual sociodemographic attributes and geographical contextual effects. The proposed methodology offers a flexible framework for modeling spatially clustered survey data widely used in social science research by explicitly accounting for spatial dependence and heterogeneity effects. The results show that neighborhood satisfaction is influenced by individual, locational, and contextual factors. Homeowners, except those of resettlement housing, tend to be more satisfied with their neighborhood environment than renters. Moreover, the impacts of housing tenure types on satisfaction vary significantly in different neighborhood contexts and spatial locations.  相似文献   

一种基于邻域数组的区域合并新方法     

刘大伟  韩玲 《测绘科学》2016,41(6):113-116,139

针对图像分割中的过分割问题,该文提出了一种区域合并方法。该方法在区域合并时采用邻域数组的数据结构来维护区域间的邻接关系,该数据结构相对传统的邻接图具有更高的效率。为了能够综合利用分割对象的各种特征,兼顾区域合并的精度与效率,将合并过程分为两个步骤进行:第一步以区域面积阈值作为合并终止条件,在合并准则中只考虑灰度信息;第二步将灰度阈值作为合并终止条件,并在合并准则中加入了纹理信息。实验结果表明,该方法能够对初分割图像进行高效且精确的合并。  相似文献   

多层权重的灰色斜率关联度分析──临涣矿井综采地质条件评价     

高文华 《煤田地质与勘探》1995,23(2):32-36

提出了一种新的多层次下各权重的确定方法──灰色斜率关联度分析法。在临涣井田实际应用表明,由该方法所求得的理论权重与实际十分吻合。   相似文献   

Lightning Nowcasting with an Algorithm of Thunderstorm Tracking Based on Lightning Location Data over the Beijing Area     

Abhay SRIVASTAVA  Dongxia LIU  Chen XU  Shanfeng YUAN  Dongfang WANG  Ogunsua BABALOLA  Zhuling SUN  Zhixiong CHEN  Hongbo ZHANG 《大气科学进展》2022,39(1):178-188

A thunderstorm tracking algorithm is proposed to nowcast the possibility of lightning activity over an area of concern by using the total lightning data and neighborhood technique.The lightning radiation sources observed from the Beijing Lightning Network(BLNET)were used to obtain information about the thunderstorm cells,which are significantly valuable in real-time.The boundaries of thunderstorm cells were obtained through the neighborhood technique.After smoothing,these boundaries were used to track the movement of thunderstorms and then extrapolated to nowcast the lightning approaching in an area of concern.The algorithm can deliver creditable results prior to a thunderstorm arriving at the area of concern,with accuracies of 63%,80%,and 91%for lead times of 30,15,and 5 minutes,respectively.The real-time observations of total lightning appear to be significant for thunderstorm tracking and lightning nowcasting,as total lightning tracking could help to fill the observational gaps in radar reflectivity due to the attenuation by hills or other obstacles.The lightning data used in the algorithm performs well in tracking the active thunderstorm cells associated with lightning activities.  相似文献   

一种基于局部分布的空间聚类算法   总被引：1，自引：1，他引：0  

刘启亮  李光强  邓敏 《武汉大学学报(信息科学版)》2010,(3)

设计了一种度量邻近域内空间实体局部分布的新指标——中值角度,在此基础上,提出了一种基于空间实体局部分布的空间聚类算法。该方法递归搜索空间实体集中所有局部分布度量值相近且非离群的点,并将其聚为一类。通过模拟数据和实际数据进行实验发现,所提出的算法比DBSCAN算法的聚类结果更合理,具有很好的抗噪性,能发现任意形状的聚类。  相似文献   

基于软约束模式的波阻抗反演   总被引：13，自引：12，他引：1       下载免费PDF全文

张宏兵  杨长春  尚作萍  杨青峰 《地球物理学进展》2006,21(3):837-844

通过在目标函数中增加先验知识约束,我们可以解决波阻抗反演的病态问题及带限问题.基于马尔柯夫随机域（MRF）的邻域系统及势函数构建一种软性约束模式,将井眼约束信息外推到井间,避免过往强制约束的不足.马尔柯夫随机域的一阶邻域偏好于常数值区域,而模型中常梯度值区域和常曲率值区域分别需要用到二阶和三阶邻域,综合使用三种类型的邻域可以改善反演效果.通过理论模型试算和实际资料处理,证明了本文提出的约束模式具有非强制性约束特点,实用性强.  相似文献   

Statistical technique to study the connection between large‐scale structures in the ISM and low‐mass star formation     

Z.T. Kiss 《Astronomische Nachrichten》2007,328(8):875-878

Applying a color index selection the Point Source Catalog of the Two Micron All Sky Survey (2MASS PSC) has been searched for Classical T Tauri (CTT) stars in the 2nd and 3rd Galactic quadrant based on their apparent K_S excess. The selection resulted in 3872 reliable CTT candidates. The obtained CTT sample is extended enough for statistical examination of the inhomogeneities in their distribution due to correlation with structures in the ISM, like infrared loops. A correlation was observed between the presence of dust loops and the CTT density. The latter shows an excess on loops with respect to that expected from random fluctuation in a homogeneous distribution matching with the observed overall distribution. Monte Carlo simulations were used to show the significance of the excess. The results imply that the formation of a fraction of CTTs was triggered during the loop formation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

风沙运动理论体系的创建与研究   总被引：6，自引：2，他引：4  

孙显科 《中国沙漠》2004,24(2):129-135

确定风、沙源、风沙流、下垫面和沙地地表形态是构成风沙运动体系的5个基本要素。确定风速的强弱、沙粒的走停、气流含沙量的盈亏、下垫面的扬抑作用和沙地地表的蚀积变化是这些基本要素各自参与风沙运动的主要表现特征。这些表现特征都能一分为二, 于是10个对立侧面的相互作用构成了风沙运动发展变化的总体。系统地研究这些侧面的组合关系、揭示它们相互促进相互制约的演变机理, 进而依其内在联系进行排序, 将其串联成一体, 并绘出图式, 这样便形成了名之曰"强、弱、扬、抑、走、停、盈、亏、蚀、积十纲辩证"的风沙运动理论体系。其中"强、弱、走、停、盈、亏、蚀、积八纲辩证"是本理论体系的核心。  相似文献   

THE FAILURE OF FEDERALISM IN CENTRAL AFRICA: A POLITICO-GEOGRAPHICAL POSTMORTEM     

《The Professional geographer》2013,65(3):224-228

Basic concepts of cultural historical geography have been applied to a variety of community issues in St. Paul, MN. Through the process a sense of place has been developed at several scales. This inclusive sense of place has provided a link among various factions and made possible several compromises in land use and economic development issues. Most of the work was done through undergraduate field seminars.  相似文献   

The Assassination of New York. Bob Fitch; From Redlining to Reinvestment: Community Responses to Urban Disinvestment. Gregory D. Squires,editor; At Road’s End Transportation and Land Use Choices for Communihs. Daniel Carlson et al.     

《Urban geography》2013,34(1):91-94

This study disentangles the relationship between income and real estate value development in Dutch urban neighborhoods. Within the literature on upgrading and downgrading, it is often assumed that neighborhood income and real estate value development are strongly linked. The results reported here—based on research in Amsterdam, The Hague, and Tilburg—indicate that income and real estate values develop simultaneously in only a relatively small number of neighborhoods, which are at the top and bottom of the housing market hierarchy. The majority reveal a more complex relationship: a number of neighborhoods show a time lag between the trends, whereas in other neighborhoods income and real estate values show partially diverging trends. Several tentative explanations are offered for the complex relationship, and stress the importance of place-specific knowledge. Three points of attention are suggested for further research: understanding the role of household dynamics, the position of neighborhoods within their urban system, and the role of the state and housing associations in neighborhood change.  相似文献