多模式智能路灯控制系统

使用AT89S52单片机作为主控芯片,设计了一种多模式智能路灯控制系统,该系统能够根据道路、巷口或定时应用3种情况进行工作模式选择,并根据环境光亮度决定是否启动所设定的工作模式.巷口工作模式时,系统通过红外传感器检测道路上有汽车或行人通过时,将识别信号送入单片机,由单片机控制交通灯开启;道路工作模式时,路灯处于开启状态,以保障行人畅行;定时模式时,通过DS1302定时模块,可以设定路灯的开关时间.此外,该系统还具有自动故障检测功能,功能全面,有较强的实用价值.     

耦合GF-2遥感影像与街景影像的广州市城中村识别

及时准确地获取城中村的空间分布及其环境质量信息对于优化城市空间、改善人居环境具有重要意义。本文以广州市越秀区为例,提出了耦合GF-2高分遥感影像和百度街景影像的城中村识别方法。首先,从街景影像中提取越秀区的街道空间品质特征;其次,在对高分遥感影像预处理并进行多尺度分割的基础上计算光谱、形状、纹理、场景特征和建筑结构5类共计23个特征;最后,融合两种影像的特征用于构建随机森林分类器进行城中村识别。结果表明,基于高分影像和基于街景影像的城中村识别整体精度分别为94.5%和85.7%,Kappa系数分别为0.58和0.31,而两者融合后的分类精度和Kappa系数为96.1%和0.67;其中基于街景影像获取的度量街道空间品质的5个指标贡献了31.6%的特征重要性。鸟瞰视野高分影像和人本视角街景影像提供的信息综合互补,构建了更有区分度的特征空间,减少了城中村的错分现象。本文证实了高分影像和街景影像在特征尺度的融合提升了城中村识别精度。街景影像中的信息可以融入到高分遥感影像等数据源中,辅助进行城中村等非正规居住空间的识别。     

基于网络形态的街道空间环境与“两抢一盗”犯罪的关系研究——以HS市原DP区为例

城市街道网络是承载人们日常行为的空间载体,街道网络及其中人的日常行为共同构成了主要的街道网络空间环境,并影响着犯罪行为的发生。既有研究表明街道空间中多发“两抢一盗”侵财类案件,并且街道网络形态和日常行为主体与犯罪存在联系,但对这一问题的深入探究较少。本文基于HS市原DP区的派出所辖区单元,使用路网数据、人口统计数据、手机信令数据等相关资料,采用空间分析和统计分析方法,对街道网络的几何形态和拓扑形态、动态人口和静态人口等因素与犯罪分布的关系展开分析,尝试探索街道网络空间环境对“两抢一盗”犯罪的影响。结果表明,街道网络空间环境中影响盗窃和两抢犯罪的要素存在较大差异。“X形单元”式街道网络、路网密度、低速交通的路网渗透性、静态人口密度和动态人口密度均对盗窃犯罪产生重要影响,与两抢犯罪相关的仅有“T形单元”式街道网络、静态人口中的实际居住户籍人员和外来人员密度,街道网络形态没有表现出与两抢犯罪的显著相关。最后提出,由于街道网络的通达性和危险性往往并存,如何通过调控或改善整体的街道网络空间环境来尽可能减少犯罪风险,是未来规划建设安全的街道网络空间需要思考的话题。     

基于TIP算法的街景漫游方法研究

街景地图是全景图与二维在线地图的结合,它以实景作为辅助传统地图抽象描述的表达手段,提高地图的空间认知功能。街景地图为用户提供固定视点的360°自由漫游与全景图点间漫游。街景地图中全景图布设呈线状分布,点间距离短、漫游频繁,因此,漫游需保持一定的空间连续与空间纵深。文中对街景地图这一全景图漫游技术应用环境的特点进行分析,引入能够从单张照片恢复一定深度信息的TIP算法,并将其运用渲染到纹理、着色器等技术,对TIP算法实现过程进行改进,在保证一定运行效率的前提下,提高街景地图的漫游效果。     

Context-aware abstraction and generalization of street networks: two cognitively engineered user-oriented approaches using network Voronoi diagrams

Generalization and spatial contextual awareness are prevalent concepts in geographic information systems. This study adopted a context-dependent user-centred network generalization method to create a sub-network for optimal route finding. The results show an increase in the number of preferred traversed edges. A route presentation approach is suggested that is based on cognitively engineered user-oriented abstraction of street network. Successive abstractions hierarchize the street network to create a hierarchical presentation structure. The route is projected onto one level in the structure. Then, instead of showing the exact route, the network Voronoi regions represented by the projected route are shown. Experience indicates that the suggested method is an efficient way of route presentation for a hierarchical regionalized structure of a human cognitive map.     

‘Big data’ for pedestrian volume: Exploring the use of Google Street View images for pedestrian counts

New sources of data such as ‘big data’ and computational analytics have stimulated innovative pedestrian oriented research. Current studies, however, are still limited and subjective with regard to the use of Google Street View and other online sources for environment audits or pedestrian counts because of the manual information extraction and compilation, especially for large areas. This study aims to provide future research an alternative method to conduct large scale data collection more consistently and objectively on pedestrian counts and possibly for environment audits and stimulate discussion of the use of ‘big data’ and recent computational advances for planning and design. We explore and report information needed to automatically download and assemble Google Street View images, as well as other image parameters for a wide range of analysis and visualization, and explore extracting pedestrian count data based on these images using machine vision and learning technology. The reliability tests results based on pedestrian information collected from over 200 street segments in Buffalo, NY, Washington, D.C., and Boston, MA respectively suggested that the image detection method used in this study are capable of determining the presence of pedestrian with a reasonable level of accuracy. The limitation and potential improvement of the proposed method is also discussed.     

After the 1997 financial crisis in Bangkok: The behaviour and implications of a new cohort of street vendors

After the 1997 financial crisis, many retrenched workers preferred not to return to provincial homes but remained in Bangkok to establish informal retail businesses in branded and other consumer products. In contrast to traditional street vendors, who specialized in food items primarily catering for low‐income customers, and focused on high volume, these ‘new generation’ street vendors also adopted more formal business practices. Given their greater sophistication and better education, we hypothesized that they would be more organized advocates of vendors' rights and thus more prone to conflicts with municipal authorities. Based on interviews, however, we found that new generation vendors are adaptive to location and business strategy, and prefer a low profile in dealing with officialdom. By contrast, traditional vendors remained more tied to particular spaces, are more likely to stand up for their rights to use public space and, because they expect more from government, are more prone to conflicts with municipal authorities. Our findings relate to ongoing discussion on the rights and needs of street vendors to access urban public space and the responsibilities of authorities to meet and provide for these informal sector livelihoods that make up a significant share of the national economy in Thailand, as elsewhere in the global South.     

对流云街激发的重力波和波动阻力

大气边界层中的对流活动,可以在其上部稳定层中激发出重力波,并引起垂直动量输送,影响到对流层和平流层中的动量平衡过程.从二层模式中大气波动方程的线性解出发,得出了对流云街激发的重力波波阻解析表达式,并讨论了大气条件对波阻的影响.这些分析可有助于大气环流模式(GCM)中此类重力波波阻参数化表达式的建立和改进.     

顾及时间效应的周围人口与视频监控对街头抢劫者作案地选择的影响研究

作案地选择是犯罪地理学的研究主题,但以往研究侧重考虑建成环境和社会环境的影响,缺乏研究周围人口与视频监控的作用。为弥补这一不足,论文以中国ZG市为例,利用离散空间选择模型,检验周围人口和视频监控对街头抢劫者作案地选择的影响,并尝试验证其时间效应。结果表明：① 周围人口与视频监控对街头抢劫者作案地选择均存在显著负影响,但两者的作用强度有所差异,即它们均能抑制街头抢劫的发生,但周围人口的监护作用大于视频监控的威慑作用;② 在周内日变化上,周围人口和视频监控的监护作用具有时间平稳性;但在日内时变化上,周围人口的影响呈现出时间波动性,而视频监控的影响却保持时间稳定特性。研究结果对警务防控和犯罪研究具有重要的参考意义,如：① 开展社会治安视频监控系统防控效果的实验评估,并对其布设位置进行动态优化与调整;② 在城市规划或城市更新时安排适量的混合功能用地,以在规划或管理上加强对周围人口的适度调节;③ 未来时间效应研究应重点关注日变化规律。     

流动商贩的空间分布特征及与正规商业的分布关系——基于距离测度方法的数量研究

有关非正规经济的空间分布特征始终缺乏宏观维度的定量研究。本文利用数字化城市管理系统中的流动商贩数据和工商局登记的正规商业数据,通过DO指数和M函数,分别探究流动商贩的空间特征及其与正规商业的分布关系。研究发现：① 绝大多数类型的流动商贩及其占地面积具有显著集聚的空间格局;其中,与居民需求较为密切的商贩类型,集聚程度相对较低。② 相较于正规商业,流动商贩在极小的空间尺度上更为强烈地集聚分布;但随着尺度扩大,集聚程度呈快速衰减态势。③ 经营内容相近的流动商贩与正规商业之间表现出显著的互斥关系,而非共栖关系;且两者的互斥程度在较小的空间尺度上尤为强烈。由此,本研究证明设立摊贩疏导区具有可行性和必要性,并就设置的类型及原则提出了初步建议。