馈能式磁流变减振器自供电特性研究

本文设计了集馈能与减振功能于一体的磁流变减振器,从能量传递的角度出发,分析了馈能式磁流变悬架系统能量流动路径,提出了馈能式磁流变减振器自供电准则。通过建立1/4馈能式悬架系统模型和基于广义回归神经网络的减振器控制器进行仿真分析,以确定所设计的磁流变减振器在不同路面激励下的自供电工作范围。     

Lightweight Occupancy Estimation on Freeways Using Extended Floating Car Data

Advanced traffic management systems rely heavily on technology to perform accurate estimations of the current state of the traffic as well as its short-term evolution. The objectives are improving traffic flow and enhancing road safety. Their success is based on accurate monitoring of two key variables, specifically speed and occupancy. The latter of the two has, to date, received significantly less attention from the scientific community. In this work we present a lightweight method to perform “on-line” occupancy estimation. We first propose three occupancy measurements calculated from data collected by a floating car: vehicle count, percentage of stop time, and headway. We then extend these discrete values to a continuous estimation of occupancy in space and time. The proposed estimators are based on a pairwise linear regression of each of the previously calculated measurements over certain references obtained from other floating cars or magnetic loop detectors. The method has been calibrated and validated under real traffic conditions and data. Despite the ease of implementation, the method is able to reproduce the occupancy values generated by the actual loop detectors, achieving promising results, with estimation errors down to 6.52%, even before multivehicle systems are considered.     

双体船的静水阻力估算

根据Fr＜0．38的9条具有对称片体的双体船的阻力试验资料，探讨了船型对剩余阻力系数CR的影响，应用归纳方法得到CR的峰、谷值及时应的傅汝德数的表达式．所有估算表达式均以参数：相对片体间距k／b、宽度吃水比b／T、棱形系数CP和排水体积长度系数CV的函数形式表示．按本文提出的双体船阻力估算方法所得结果与模型试验的吻合比较满意．     

10CrNi3MoV船用钢屈服强度检验异常结果的界定

应用数理统计方法对10CrNi3MoV船用钢的屈服强度和化学成分的试验数据进行回归分析,获得两者间的回归方程;并结合该钢的检验标准,确定其屈服强度检验结果的异常界限。     

基于乘客满意度的公交车站立乘客面积研究

公交车内站立乘客面积是影响公共交通乘车阶段乘客满意度的关键指标.将使乘客感受由不满意转变为满意的公交车站立乘客面积的临界值定义为临界站立乘客面积.本文旨在提出临界站立乘客面积的建议值.首先,在呼和浩特市开展了客流调查及问卷调查;然后,基于调查所获数据,采用有序 Logistic回归建立了乘客满意度与站立乘客面积的模型;最后,通过对所建模型的图形化分析,提出临界站立乘客面积(即保证乘客满意的最小站立乘客面积)的建议值为 0.25 m2/人.本文研究成果为公共交通乘车阶段的乘客满意度评价、舒适性评价提供量化依据,为公交车额定载客量的核定提供新思路.     

基于支持向量回归机的道路交通事故预测模型研究

针对道路交通事故预测具有随机波动性较大、信息量较少和非线性数据序列预测的特点,引入支持向量回归机（SVR）,建立基于SVR的道路交通事故预测模型。通过实例计算,证明基于SVR的道路交通事故预测模型具备非线性、所需数据资料较少、建模简单和计算快捷等优点,同时与RBF神经网络预测模型相比,该模型的预测精度高、泛化能力强,更适用于道路交通事故预测。     

大城市合理客运交通出行结构研究

通过考察国际大都市公共交通结构的主要特征,总结出大城市合理客运交通结构的发展趋势。基于对10个国际大城市的相关指标回归分析,探讨了大城市合理公交出行结构预测模型;最后,以杭州为例,应用预测模型,在分析杭州客运交通结构与国际知名大都市客运交通结构的差异以及产生差距原因的基础上,确定了杭州市在地铁建成后的合理客运交通结构。     

基于GA-LSSVR模型的路网短时交通流预测研究

目前,很多短时交通流预测方法仅利用某一路段历史数据的时间相关性或者道路上下游路段的时空相关性进行交通流预测,未充分考虑路网所有路段之间的时空相关性.提出了一种基于稀疏混合遗传算法优化的最小二乘支持向量回归(LSSVR)模型,并应用于路网短时交通流预测.该预测模型不仅可以自动优化LSSVR模型参数,而且可以从高维路网交通流数据中选择有助于交通流预测的变量子集.实验结果表明,与LSSVR模型相比,所提方法具有更好的预测能力;而且,少量时空变量被选择出来构建预测模型,极大减少了信息冗余,改进了模型可解释性.     

LNG运输船船型浅析

简述了LNG船的沿革、液货舱的类型及典型结构、总布置特征、船舶要素特征以及具体防火要求，并根据大量的实船资料，通过回归统计分析的方法得出船舶主尺度与总吨位间的系列关系曲线。     

Improvement in the estimation and back-extrapolation of CO2 emissions from the Irish road transport sector using a bottom-up data modelling approach

Road transport is a major source of CO₂ emissions in Ireland and accounts for almost 96% of the total CO₂ emissions from the transport sector. Following the recent adopted UNFCCC reporting guidelines on annual inventories [24/CP.19], this study applied the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (2006 IPCC GLs) tier 3 approach to estimate CO₂ emissions from road transport at the vehicle category level, for the first time in Ireland. For this, disaggregated datasets were prepared based on year of vehicle registration and mileage since registration of the vehicle. Such an approach provided a more realistic national scenario in comparison to the use of average mileage degradation in emission calculations. This investigation comprised a recalculation of previous emissions estimates (1990–2012) and an estimation of CO₂ emissions in 2013 using a previously unavailable level of data disaggregation for vehicle mileage as well as using vehicle class specific data and an improved bottom-up estimation methodology in COPERT. Historic vehicle fleet data were restructured, annual mileage data were estimated in relation to the fleet data and back extrapolated using a regression approach.The results showed that the mileage degradation was not only subject to fuel technology, engine size, and age but also the emissions class and vehicle category. It was also observed that the disaggregated level of data provided a different CO₂ emissions split among the vehicle categories than that of previous estimations which were based on an aggregated level of data. Previous emissions inventories (1990–2012) were shown to have underestimated the share from diesel fuelled passenger cars by more than 56% in 2012. Diesel fuelled passenger cars were also found to account for the majority of CO₂ emissions from road transport activities in Ireland in 2013. The level and trend assessment showed that emissions from Euro-II and Euro-III classed vehicles especially for passenger cars, which have a significant contribution to the total emission in 2013 have caused an increase in fleet level emissions in Ireland. In addition, the results also showed that the emissions share from Light Duty Vehicles and Heavy Duty Vehicles were overestimated by previous investigations. This paper highlights the importance of the resolution of data used in emissions inventory preparation which may impact upon future projections and policy formulation. The findings of this investigation are also discussed in relation their implications for road transport policy, including carbon taxation and future policy options aimed at achieving EU emissions target in 2020.