大跨悬索桥MTMD抖振控制的参数优化

针对悬索桥抖振控制问题,建立有限元模型,应用神经网络和遗传算法对多重调频质量阻尼器(MTMD)进行双参数优化。以某大跨悬索桥为例,利用神经网络改进的谐波合成模拟方法(RBF-WAWS法)对脉动风速进行模拟,并换算成抖振力作用主梁上,通过时程分析及后处理获取主跨跨中横桥向响应值。将响应值的均方差作为优化目标函数,以MTMD总质量、个数及阻尼比作为优化变量和约束条件,采用神经网络拟合目标函数并应用改进的自适应遗传算法进行寻优。结果表明,优化后的MTMD能有效控制悬索桥在脉动风作用下的抖振响应,减振率达48%。提出的理论与计算方法对悬索桥中MTMD的设置及参数选取具有实际工程意义。     

船舶电子证书应用及监管思考

对于如何保证船舶证书和技术文件的完整可查,提出相应的船舶电子证书应用及监管思考。介绍船舶电子证书可进一步拓宽无纸化办公领域、提高检验过程的便利性、提高港口检查的高效性,并可大幅减少证书制作成本、缩短寄送时间,有效提升工作效率;同时,可促进相关部门船舶智能化管理的优化升级。     

一种内河船舶吃水检测系统设计

船舶在通过船闸和升船机等通航设施时因超吃水会导致安全事故,目前常见的船舶吃水检测方法均存在弊端,无法满足检测需求。结合超声波衍射原理,设计一种基于侧扫单波束阵列的吃水检测系统,详细介绍该系统的组成及功能,并在葛洲坝船闸进行安装和测试。结果表明,该系统具有水质适应性强、易于安装、维护方便等优点,能够有效检测船舶动态吃水,测量值与实际核实吃水值的标准差小于0. 086 m,对过闸船舶具有一定的预警作用。     

Developing an enhanced weight-based topological map-matching algorithm for intelligent transport systems

Map-matching (MM) algorithms integrate positioning data from a Global Positioning System (or a number of other positioning sensors) with a spatial road map with the aim of identifying the road segment on which a user (or a vehicle) is travelling and the location on that segment. Amongst the family of MM algorithms consisting of geometric, topological, probabilistic and advanced, topological MM (tMM) algorithms are relatively simple, easy and quick, enabling them to be implemented in real-time. Therefore, a tMM algorithm is used in many navigation devices manufactured by industry. However, existing tMM algorithms have a number of limitations which affect their performance relative to advanced MM algorithms. This paper demonstrates that it is possible by addressing these issues to significantly improve the performance of a tMM algorithm. This paper describes the development of an enhanced weight-based tMM algorithm in which the weights are determined from real-world field data using an optimisation technique. Two new weights for turn-restriction at junctions and link connectivity are introduced to improve the performance of matching, especially at junctions. A new procedure is developed for the initial map-matching process. Two consistency checks are introduced to minimise mismatches. The enhanced map-matching algorithm was tested using field data from dense urban areas and suburban areas. The algorithm identified 96.8% and 95.93% of the links correctly for positioning data collected in urban areas of central London and Washington, DC, respectively. In case of suburban area, in the west of London, the algorithm succeeded with 96.71% correct link identification with a horizontal accuracy of 9.81 m (2σ). This is superior to most existing topological MM algorithms and has the potential to support the navigation modules of many Intelligent Transport System (ITS) services.     

基于VRML的虚拟现实技术在数字管道中的应用

介绍了虚拟现实建模语言(VRML),将基于VRML的虚拟现实技术和HTML、 JavaScript相结合,并应用到数字管道中,构建了真实感强、交互性强的可视化虚拟石油管道场景和管道泄漏模型,实现了石油管道虚拟场景的漫游,以及用户与虚拟场景的交互,并及时、直观地反映管道泄漏.应用结果表明:将基于VRML的网络交互式虚拟现实技术应用到数字管道,促进了数字管道的信息共享,提高了数字管道的决策管理效率.     

Using on-board logging devices to study the longer-term impact of an eco-driving course

In this paper the long-term impact of an eco-driving training course is evaluated by monitoring driving behavior and fuel consumption for several months before and after the course. Cars were equipped with an on-board logging device that records the position and speed of the vehicle using GPS tracking as well as real time as electronic engine data extracted from the controller area network. The data includes mileage, number of revolutions per minute, position of the accelerator pedal, and instantaneous fuel consumption. It was gathered over a period of 10 months for 10 drivers during real-life conditions thus enabling an individual drive style analysis. The average fuel consumption four months after the course fell by 5.8%. Most drivers showed an immediate improvement in fuel consumption that was stable over time, but some tended to fall back into their original driving habits.     

一种基于独立成分分析和径向基神经网络的人脸识别新方法

提出了一种新的基于独立成分分析和径向基神经网络的人脸识别方法。独立成分分析可以从高阶上消除特征数据的相关性,改进了主成分分析方法只能从2阶上消除数据相关性的弱点;最终特征数据的分类由RBF神经网络来实现。在人脸数据库上的实验结果表明该新方法的识别性能较其他方法有了很大提高。     

人的可靠性分析方法及其在军事活动中的应用

回顾了人的可靠性分析发展的历史和现状,重点对现在已存在的人的可靠性分析方法进行了介绍分析,提出并简要介绍了两种在军事活动中适用的人的可靠性评估方法的基本原理：基于粗糙集的人的可靠性评估法和基于贝叶斯的人的可靠性评估法,最后分析了人的可靠性研究中存在的问题。     

基于BP-DS证据理论的航标状态识别模型研究

内河航标标示了可航行水域的边界,是保障内河船舶安全航行的重要前提.面向内河航标不同故障模式,构建一种基于BP-DS证据理论的航标状态识别模型.采用两个BP神经网络分别训练航标基础属性数据与环境因素数据,计算独立的证据值;通过DS证据理论实现航标运行状态识别结果的决策融合.结果表明,基于BP-DS证据理论的航标状态识别模...     

哈大高铁影响下东北城市群交通网络空间结构特征研究

哈大高铁的运行缩短了东北城市群之间的相对距离,优化了东北城市群城市交通网络空间结构.通过建立向心性分形模型以及相关性分形模型,以交通距离代替空间的实际距离来研究城市群之间分形特征,通过城市间高速铁路时间距离和高速公路时间距离进行对比,计算高铁开通前后东北城市群交通空间聚集维数和空间关联维数,分析东北城市群交通网络空间结...