HARD2006在公路设计中的应用

海地公路优化设计系统HARD2006是国内首个引入数字化地面模型（简称DTM）技术的公路设计系统,真正实现了三维设计,具有强大的公路平、纵、横断面设计能力,自动生成公路各种图表。本文介绍了HARD2006主要的功能,并以实例说明其在工程中的应用。     

舰用中频机组带整流负载的建模与仿真分析

根据整流桥的运行状态,建立起中频机组带整流桥负载的数学模型,利用matlab/simulink中的电力系统模块(PSB)搭建系统的仿真平台.验证了非线性负载对中频电网的影响同时分析了旋转变频机组的滤波作用,为舰用中频电网的分析提供了有效的分析工具和试验参考.     

一种新型轨道减振器的静态特性研究

介绍一种新型结构的压剪复合板式轨道减振器.详细分析了该结构的竖向双刚度、横向静刚度性能以及竖向预载对横向刚度的影响.研究表明,这种压剪复合板式结构,既能有效确保元件具有良好的稳定性及承载能力,又能使元件具有优良的隔振性能,特别适用于客流密度较大且隔振要求较高的地段.     

Relationships between characteristics of motorcycles and hydrocarbon emissions in Taiwan: A note

Taiwan’s inspection and maintenance (I/M) programs identifies high-emission motorcycles but, although these help reduce air pollution, they have been criticized for being cost-ineffective. This study examines the relationship between characteristics of motorcycles and hydrocarbon emissions in the Central Air Quality Basin of Taiwan. It is shown that engine size and type, age and manufacturer of a motorcycle significantly affect HC emissions. Larger-size engines emit smaller amounts of HCs; whereas older motorcycles emitted greater amounts. In addition, two-stroke-engine machines produced significantly higher HC emission levels than four-strokes. Variations in HC emissions testing are a result of various I/M testing locations and efficiency may be improved by modifying these.     

预应力混凝土连续刚构桥病害分析及加固技术

箱梁底板砼拉崩、横斜裂纹是连续刚构桥常见病害。文中根据对两座同种结构尺寸刚构桥产生病害的原因分析。分别采用钢横梁和横肋加固方案,取得了良好的效果,同时说明了对同类型桥梁在跨中增加横肋会起到一定的预防作用。所介绍的加固方案设计及实施过程对类似病害的处理具有一定的借鉴作用。     

箱形驳船底部砰击载荷及结构加强要求研究

针对箱形驳船,建立了三维水动力计算模型,对箱形驳船系列在设计海况下的船体与波浪之间的相对运动和相对速度做了短期预报。运用Ochi船舶砰击理论,分析了箱形驳船在不同吃水和拖航速度时船首砰击的发生概率和砰击压力极值等,并讨论了吃水、拖航速度等因素对箱形驳船底部砰击特性的影响。在此基础上,提出了箱形驳船首部砰击加强的临界航速建议,为箱形驳船规范中有关底部砰击载荷的修订提供参考和依据。     

上海A7高速公路掘石港大桥施工

该文详细介绍了跨径为45m＋70m＋45m三跨变截面连续梁的上海市A7高速公路掘石港大桥的施工方法,其中分别介绍了水深较深的水中墩施工技术及上部结构施工技术。     

Short-term prediction of vehicle waiting queue at ferry terminal based on machine learning method

Ferry service plays an important role in several cities with waterfront areas. Transportation authorities often need to forecast volumes of vehicular traffic in queues waiting to board ships at ferry terminals to ensure sufficient capacity and establish schedules that meet demand. Several previous studies have developed models for long-term vehicle queue length prediction at ferry terminals using terminal operation data. Few studies, however, have been undertaken for short-term vehicular queue length prediction. In this study, machine learning methods including the artificial neural network (ANN) and support vector machine (SVM) are applied to predict vehicle waiting queue lengths at ferry terminals. Through time series analysis, the existence of a periodic queue-length pattern is established. Hence, methodologies used in this study take into account periodic features of vehicle queue data at terminals for prediction. To further consider the cyclical characteristics of vehicle queue data at ferry terminals, a prediction approach is proposed to decompose vehicle waiting queue length into two components: a periodic part and a dynamic part. A trigonometric regression function is introduced to capture the periodic component, and the dynamic part is modeled by SVM and ANN models. Moreover, an assembly technique for combining SVM and ANN models is proposed to aggregate multiple prediction models and in turn achieve better results than could be attained from a lone predictive method. The prediction results suggest that for multi-step ahead vehicle queue length prediction at ferry terminals, the ensemble model outperforms the separate prediction models and the hybrid models, especially as prediction step size increases. This research has important practical significance to both traffic service management interests and the travelers in cities along waterfront areas.     

复合材料在海军舰艇上的国外应用现状及进展

随着军方努力降低舰艇的购置和维护成本、提高其结构和操作性能,自20世纪80年代中期以来,复合材料的应用日益增加。该文综述了近年来复合材料在海军舰艇上的国外应用现状及进展,包括在大型军舰如护卫舰、驱逐舰和航空母舰上的机械及其他装备,以及上层建筑、甲板、舰舱壁、先进的桅杆系统、螺旋桨、推进轴系、方向舵、管道、泵、阀等上的应用。     

地铁隧道底部探测技术及应用

地铁工程不仅要保证施工过程中的安全,而且要保障长期运营中的安全,因此隧道底部地质环境是地铁工程需重点考虑的特殊问题.文章介绍了地铁隧道底部地质探测的必要性,总结了国内外专家关于地铁隧道地质探测方法的研究成果;针对地铁工程的特殊性,提出了地铁隧道底部探测预报措施以地质法为基础、其它方法综合运用的原则,对探测技术的原理作了论述."武汉地铁二号线虎泉段隧道底部岩溶探测"项目的应用实践结果表明,该项探测技术能够基本满足地铁工程需要,探测准确度较高,值得在地铁工程中推广,有必要进行更深入的研究.