基于GPRS的远程LED显示屏控制器的研究

针对Luminary微处理芯片为控制器的点阵LED显示屏控制系统,采用GPRS/GSM通信标准,通过LM3S1138的串行接口接收无线模块的控制命令及显示数据,经处理后控制LED显示屏的扫描显示。本文给出了该系统的设计方案,以及软硬件的详细设计过程。     

GPS在现代公路勘测中的应用

公路建设工程日益增多,传统的测量方法已不能满足新的要求,因此,GPS以其高精度、快速度、低费用等优点在公路建设中得到了广泛的应用。     

Do modes of transportation and GPS affect cognitive maps of Londoners?

Legibility has long been recognized as an important factor in creating a good image of a city in individuals’ minds. This image is perceived to assist people in understanding the city, finding their way, and recalling the city. The quality of the image affects individuals’ abilities in way-finding. This is especially important for cosmopolitan and global cities such as London in order to preserve resources and time, manage travel costs, limit pollution (air or noise) and enhance these cities as places to live, work and visit. This research examines the cognitive maps of London drawn by a sample of its residents to discover how different modes of transportation and GPS usage could affect individuals’ urban images. Such research is useful for town planners, local government departments, and urban and transport planners because of the way it considers the legibility of London as and provides a tool to study individuals’ urban images. 101 participants were recruited with at least a two-year residency from both genders (38.6% females and 61.4% males) with the average age of 33.88 and S.D. = 10.63. The results suggest car use has a positive correlation with seeing London in city scale and GPS usage has a negative correlation. Whilst recent studies have shown that there are differences between active travel modes (e.g., walking, bicycle riding or driving a car) and passive modes (e.g., as a passenger taking a bus, train or taxi), this study indicates that GPS usage also influences cognitive maps, with a negative correlation found between GPS usage and drawing maps on a city scale. Other significant associations were found for the car drivers with a positive relation with the number of roads mentioned on the maps, seeing London in city scale and having a two-dimensional façade image of the city in mind.     

基于GAMIT高精度GPS基线数据方法

随着GNSS技术的不断向前发展,精密GPS数据越来越受到研究者重视。以目前应用广泛的GAMIT软件作为研究对象,论述GAMIT软件安装过程及文件配置过程,并在此基础上通过实验对部分影响GPS解算精度的控制参数进行分析,从而得出截止高度角在10°时为最佳条件,双频观测量相对于单频观测量可更精确解算处理长基线的结论。     

铁路货车及调车机跟踪管理系统的设计与实现

铁路货车及调车机跟踪管理系统采用基础数据层、业务逻辑处理层、数据展现和分析层三层结构设计。通过企业服务总线(ESB)整合现在车、行车日志、货运管理、车载计算机和GPS定位等现有应用系统,GPS实时定位调车机位置,完成调车计划执行的实时数据采集。     

基于VBA的公交上车刷卡人数统计方法

提出一种基于VBA宏命令,利用公交IC卡和GPS数据来实现各站点刷卡上车人数统计的方法.根据两种数据的特点,以Excel为主要工作平台,通过VBA程序快速地对两者数据进行筛选和利用,逐步实现各站点公交车到站时间的匹配和各站点上车人数的统计.最后利用此方法对丹东市公交线路的往返各站点上车人数进行统计.与传统的公交随车调查结果对比,通过该方法得到的各站点上车人数数据较为准确,可作为传统方法的替代.     

基于改进极限学习机的公交站点短时客流预测方法

以公交车IC 卡和GPS数据为基础，提出了一种基于改进粒子群算法优化极限学习机(IPSO-ELM)的公交站点短时客流预测模型.依托IC 卡和GPS 数据在站点的特征表现和内在联系，定义了站点间距，并分析了站间距和车辆到总站距离间的联系；提出了公交乘客上车站点确定方法，进而得到公交站点上车客流量；通过分析公交客流数据特征，确定ELM输入参数维度，并采用IPSO 算法找到ELM的最优隐含层节点参数；最后依托广州市19 路公交车客流数据仓库进行了方法验证.结果表明：所用优化后的ELM方法预测误差在10%以内，并与应用广泛的SVM、ARIMA和传统ELM模型进行对比分析，发现改进的ELM方法拥有更高的可靠性和泛化性能.     

The authors in this issue

This paper considers the main road-traffic parameters that determine air pollution, i.e. the total volume of traffic, road speeds and the composition of the vehicle fleet. Changes in the amounts of pollutants emitted, and the importance of each of the three parameters, have been computed by using a traffic assignment model, which also represents emission factors. The types of policies that may be implemented to reduce the environmental impact of transport are then considered. The study demonstrates, for example, that the impact of a deterioration in traffic conditions is limited in comparison with the effect of forecast increases in traffic and improvements in the environmental performance of vehicles. As a consequence, if cities and urban transport are to achieve sustainable development, urban expansion must take place in a controlled way.     

浅谈道路交通地理信息系统研究框架

针对地理信息系统在道路交通领域的应用 ,就研究发展方向谈了自己的认识和看法     

GSM短信技术在电力变压器监测系统中的应用

铁路沿线电力变压器的负荷检测及管理是供电段的主要工作之一,在线监测能够提高铁路沿线电力变压器的运行可靠性,并且根据检测结果管理部门还能对各容量的变压器进行有效配置,提高了其运行经济性。在线监测中,通信方式的选择是关键。在分析各种通信方式优缺点的基础上,着重介绍了GSM短信通信技术在配电变压器在线监测系统的实现及应用。