Speed profile estimation using license plate recognition data

Vehicle speed profile is a fundamental data support for calculating vehicular emission using the micro-emission model. However, achieving accuracy and breadth for the speed profile estimation is difficult. This study proposes a new vehicle speed profile estimation model using license plate recognition (LPR) data. This model allows speed profile estimation of every individual vehicle between two consecutive intersections. A systematic LPR data-mending method is developed to infer the information of unmatched vehicles. Using the complete arrival and departure information as boundary conditions, a customized car-following model combined with dummy-overtaking hypothesis and boundary constraints is then applied to estimate the speed profile of vehicles. The proposed model is validated using ground truth speed information from a field experiment conducted in Langfang City in China. Results show that the model can fully capture the pattern of ground truth speed profile. A complementary model validation using the Next Generation Simulation dataset and a model application for calculating emissions are also conducted. The numerical results indicate the effectiveness of the proposed model in estimating vehicle speed profile and emissions.     

A scalable communication middleware for real-time data collection of dangerous goods vehicle activities

Recently, real-time monitoring of Dangerous Goods Transport has drawn a lot of attention, thanks to its capability to provide a better visibility on dynamically moving vehicles, particularly through a Web Mapping application. Yet, one of the challenges to be faced designing such a system is an effective architecture for real-time collection of telemetry and event data conveyed by the vehicle on-board system, such the Global Positioning System coordinates. In this paper, we have focused on optimizing the process for managing a large quantity of data transmitted via network sockets that use the Transmission Control Protocol. Then we prove the process efficiency through performance and scalability tests. The middleware is being implemented as a part of a project that aims to monitor the Italian petrochemical company Eni’s oil trucks shipment along Europe and USA territories.     

大榭第二大桥钢塔节段制造工艺及焊接变形控制技术

针对大榭第二大桥钢塔节段的结构特点,从制作工艺、焊接变形控制等方面介绍了控制钢塔精度的方法,为今后钢塔节段制造提供技术参考.     

连云港25万t级矿石码头工程北围堤建设关键技术

为建设25万t级矿石码头,连云港港将后方北围堤作为永久性驳岸.针对软土地基及周边限制条件,进行围堤地基处理方式、施工控制要点、运营期监控等研究.对围堤设计、施工、检测各阶段关键技术,进行全过程探讨.该工程的完成,为同类大型码头建设提供了有益的参考.     

A model and solution algorithm for dynamic deterministic user equilibrium assignment

Abstract

In this paper a route-based dynamic deterministic user equilibrium assignment model is presented. Some features of the linear travel time model are first investigated and then a divided linear travel time model is proposed for the estimation of link travel time: it addresses the limitations of the linear travel time model. For the application of the proposed model to general transportation networks, this paper provides thorough investigations on the computational issues in dynamic traffic assignment with many-to-many OD pairs and presents an efficient solution procedure. The numerical calculations demonstrate that the proposed model and solution algorithm produce satisfactory solutions for a network of substantial size with many-to-many OD pairs. Comparisons of assignment results are also made to show the impacts of incorporation of different link travel time models on the assignment results.     

乡镇船厂焊接工艺认可

结合广东省乡镇船厂实际，介绍钢板对接焊和角接焊的焊接工艺认可流程、技术标准和有关注意事项。     

浙赣线CTC运用探讨

结合浙赣线CTC系统的建设实际，针对繁忙干线轨道运用复杂的大型编组站或区段站，列车运行控制和调车运行控制之间的冲突，以及CTC区段与非CTC区段的衔接问题，提出了解决方案。     

我国城市轨道交通车辆的发展和实施车辆国产化的历程

我国城市轨道交通在上世纪90年代以后得到迅速发展,A、B型地铁车辆在各大城市得到了广泛应用,跨座式单轨交通车辆和低地板车辆也投入了运营.城市大力发展轨道交通,其车辆需求量剧增,车辆国产化意义重大.指出我国城轨车辆的平均国产化率在逐步提高,尤其在电传动及其控制系统和制动系统国产化方面取得了长足的进步.     

生产过程实时仿真系统

Network 90分布式过程控制系统是Elsag-Bailey集团八十年推出的产品，在我国许多企业生产过程自动控制中有着广泛的应用．但受产品生产年代的制约，N90上运行的许多管理软件运行在DOS环境下，已不能适应今天企业发展的需要．生产过程实时仿真系统将原N90系统中的MCS仿真软件移植到WindowS95／98环境下的网络工作站上，有效地解决了这一问题．本文详细地阐述了生产过程实时仿真系统的功能及结构．     

经营性高速公路建设程序与相关法律的研究

分析了经营性高速公路的经济特性,对我国现行的经营性高速公路的建设程序、投资体制和相关法律进行了研究,指出我国目前经营性高速公路的建设程序、投资体制不符合经营性高速公路的经济特性,不利于市场竞争,没有合理界定政府和投资人的职责。提出了相关的法律法规的修改意见,设计了符合市场竞争特性的建设程序。