WebGIS中三层结构技术的应用

为了寻找一种适合民航运输行业特点的GIS建设方案，在比较了几种GIS设计方案，分析了WebGIS的特点，对目前三种主要的WebGIS实现方法进行了研究，最终选择了三层结构的客户机／服务器模型作为实现民航运输地理信息系统的基本框架；从逻辑结构和功能结构两方面，对三层结构模型进行了详细介绍，并简要介绍了三层结构模型在民航运输地理信息系统中的具体实现。通过实践，尽管还存在一些缺点有待克服，但三层结构客户机／服务器模式的WebGIS所具有的维护少，操作简便，客户端要求低，可以较好平衡负载等特点，使它成为一种理想的、适合民航运输业用户分散、数量众多、数据量大等特点的地理信息系统建设方案。     

三维GIS在铁路勘测设计中的应用

传统的铁路勘测设计成果多为二维地图,三维表示则独立地以其他CAD系统实现,勘测设计无法集成到同一平台.而三维GIS应用于铁路勘测设计则可以实现数据获取、处理与应用的一体化、表示的多维化与动态化.具体技术包括数据获取和处理、数据集成管理、数据可视化等.     

GPS隧道控制网横向贯通精度估算

以GPS测量的基线向量为观测量，推导出适合GPS隧道控制网横向贯通精度的计算式．经实例验证，忽略观测量协方差的计算结果与严密计算结果非常接近；采用GPS接收机标称精度进行估算，其结果也满足隧道控制网的要求．这种估算横向贯通精度的方法完全适合GPS隧道控制网的测前设计．算例结果表明，影响隧道横向贯通精度的主要因素是两端洞口进洞基线方位角测量的相对精度．     

基于GIS的特殊人群进出场交通模拟系统的设计与开发

本文针对大型活动中的特殊人群进出场交通,设计和开发了基于GIS的交通模拟系统,用于帮助交通管理部门制定交通组织方案,解决大型活动举行期间城市道路上的交通拥挤问题。系统开发成功后被应用于十运会举行期间的交通管理,取得了良好的效果。     

GIS支持下的高速公路路灯监控管理系统设计

介绍了我国高速公路行车和路灯设施管理的特点,在对系统建设的必要性进行分析的基础上,提出了建立基于GIS的高速公路路灯监控管理系统的总体方案。并对系统体系结构和各子系统功能模块进行了详细的设计,最后阐述了系统数据处理流程。     

基于GIS的矿区地表移动监测数据管理系统

用Visual Basic语言作为开发工具,用ESRI MapObjects为GIS平台软件,设计并开发了矿区地表移动监测数据管理系统,解决了长期以来监测数据管理繁杂、手段落后、分散不集中以及不顺应信息化、自动化和无纸化办公趋势的问题,实现了地表移动监测数据存储、管理、查询和图形化输出的一体化.     

The cumulative effect of nuisances from road transportation in residential sectors on the Island of Montreal – Identification of the most exposed groups and areas

Air pollution and road traffic noise are considered to be the two most important nuisances that could negatively affect the quality of life. A prolonged exposure to high concentrations of these pollutants could conduct to various health problems. Studies in environmental equity have often considered these nuisances individually whenever it comes from the same source. The main objective of this paper is to determine if the 15 years of age, those aged 65 and over, visible minorities and low income individuals located in a portion of the Island of Montreal are overrepresented in city blocks characterized by having among the highest levels of transportation-related air pollutants (i.e., ambient concentrations of NO₂ and road traffic noise in decibels (dB(A)). The results show that low-income individuals and, to a lesser extent, visible minorities, are significantly overrepresented in city blocks characterized by the higher levels of NO₂ and road traffic noise in dB(A). Multinomial logistic regression analysis confirms these results, and also shows that young people under 15 years are under-represented in the most polluted areas. However, contrary to the previous bivariate results, people aged 65 and over are negatively and significantly associated with the likelihood of their living in a city block located in an advantaged area after controlling for the independent effects of the other explanatory variables. Moreover, visible minorities are significantly overrepresented in advantaged areas. Considering the observed results, some solutions are identified to reduce road traffic noise and air pollution in the city blocks localized near major traffic arteries.     

Spatial and temporal distribution of expressway and its relationships to land cover and population: A case study of Beijing,China

The interaction between urban transport, land cover change and the distribution of population is a typical manifestation of the urbanization process. As high-grade road, expressway plays a significant role in promoting resource circulation and economic development. Based on the road distribution, land cover and population census data, this study specifically probed the relationship between the expressways and the land cover and population of Beijing. The results show that: (1) as the distance from an expressway increases, the amount of built-up land gradually decreased, and the transfer of land cover near the expressway was more intensive and frequent when compared with that of the whole city; (2) In 2010, a district that was less than 3 km from both sides of the expressway and which occupies one-quarter of the entire city had concentrations of 42% industrial land, 58% of settlement land, and 76% transportation land of the entire city; (3) As for Beijing, the population density was positively correlated to road density, and population density declined with a corresponding increase in buffer distance; (4) The ring area between the Fifth and the Sixth Ring Road featured the greatest density of expressways and the most dramatic changes in both land cover and population. According to our study, there’s a positive interactive feedback relationship between the expressways, land cover and population of Beijing. Also, due to the concentration of population, industry and transport system around the expressways, special attention should be paid to environmental pollution and the inhabitants’ health in this area.     

浅谈GPS在高等级公路测量中的应用和发展前景

叙述GPS的组成,GPS系统在公路测量中与传统的测量设备对比的优点,GPS测量在高速公路中的应用及发展前景。     

Using smartphones as a very low-cost tool for road inventories

Road inventories are a key component in the planning of road networks as they allow for efficient management and a better return on the investment. Current techniques for carrying out road inventories are expensive and entail long planning processes and data postprocessing. Furthermore, these inventories are only useful to those parties interested in designing and building road networks. This study presents a new method for create road inventories based on the use of the latest generation cellular phones, also called smartphones. This paper describes the use of several mobile apps developed for this project that were implemented during the different stages of road inventory process. The results indicate that the data processing speed, its low cost, and the ease of implementation from any type of vehicle validate the proposed procedure as an invaluable tool (1) to do inventories of all types of road networks that are not accessible to cars; (2) to manage the routine maintenance of small road networks; and (3) as a basis for future research projects on road design and outline.