西部陆海新通道货运量预测研究

西部陆海新通道在区域协调发展格局中具有战略地位,对我国深化陆海双向开放、推进西部大开发形成新格局等具有重要意义.在分析西部陆海新通道总体规划及铁路网规划的基础上,结合西部陆海新通道功能定位,分析货运量影响因素,从区域间货运量、对外贸易货运量、分流沿江通道货运量3个方面进行运量预测.针对每部分货运量,在分析历年货运量的基...     

Utilization patterns of park and ride facilities among Kuala Lumpur commuters

A parking utilization survey was undertaken with the main objective of analyzing and comparing the daily workday utilization patterns of two main park and ride stations within the Kuala Lumpur conurbation. This study also aimed to gauge the level of usage of the park and ride facilities. The findings showed that the overall utilization pattern of the facilities was very high with a utilization rate of between 80 and 95%. The stations, however, recorded a contrasting accumulation pattern. The study further revealed that most of the rail-based suburban park and ride users were long term parkers. The results of this study are comparable to results of similar studies in Seoul, Calgary, Tyne and Wear and others. Since parking availability is an important factor that has influence on the behavior of a park and ride user, more accurate information relating to the supply and demand of the park and ride facility will assist in planning new transport infrastructure.

Accuracy of the Gothenburg congestion charges forecast

This paper explores the accuracy of the transport model forecast of the Gothenburg congestion charges, implemented in 2013. The design of the charging system implies that the path disutility cannot be computed as a sum of link attributes. The route choice model is therefore implemented as a hierarchical algorithm, applying a continuous value of travel time (VTT) distribution. The VTT distribution was estimated from stated choice (SC) data. However, based on experience of impact forecasting with a similar model and of impact outcome of congestion charges in Stockholm, the estimated VTT distribution had to be stretched to the right. We find that the forecast traffic reductions across the cordon and travel time gains were close to those observed in the peak. However, the reduction in traffic across the cordon was underpredicted off-peak. The necessity to make the adjustment indicates that the VTT inferred from SC data does not reveal the travellers’ preferences, or that there are factors determining route choice other than those included in the model: travel distance, travel time and congestion charge.     

海运法律中限制“合同自由”原则的历史变迁

1893年美国《哈特法》的制定标志着法律开始限制航运界的盛行已久的"合同自由"原则.此后不到一个世纪,《海牙规则》、《海牙-维斯比规则》和《汉堡规则》的相继出台,使得立法对海上货物运输合同的规制趋于严格,这引起了国际航运界普遍不满.2008年《鹿特丹规则》为适应航运市场新形势,赋予了批量合同较大的合同自由.     

LNG船液舱晃荡的数值模拟

随着海上液化天然气开采和卸载的发展，LNG船非充满舱的晃荡问题已成为一个重要的研究课题。基于流体体积（VOF）法描述晃荡流场的自由面，结合动网格技术，建立了适合不同几何形状的液舱晃荡数值模拟的计算方法。首先针对二维矩形舱和三维立方体舱及薄膜型舱进行了计算，并将相关的横向力、波高和压力曲线与试验结果作对比，吻合较好，验证了此法的可行性和有效性。然后，对三种不同类型的LNG液舱模型（球形舱、圆柱形舱和薄膜型舱）分别进行了系统的晃荡数值计算与分析，将三者的力、力矩、压力计算结果以及自由液面形状进行了比较分析。结果表明，三种液舱模型在晃荡过程中的结果和现象十分类似，通过对液舱在晃荡过程中的受力和舱室容积的综合衡量，作为一种LNG船的新型舱室，圆柱形舱室是很有发展前景的。     

Statistical characteristics of transitional queue conditions in signalized arterials

The performance of signalized arterials is related to queuing phenomena. The paper investigates the effect of transitional traffic flow conditions imposed by the formation and dissipation of queues. A cross-recurrence quantification analysis combined with Bayesian augmented networks are implemented to reveal the prevailing statistical characteristics of the short-term traffic flow patterns under the effect of transitional queue conditions. Results indicate that transitions between free-flow conditions, critical queue conditions that exceed the detector’s length, as well as the occurrence of spillovers impose a set of prevailing traffic flow patterns with different statistical characteristics with respect to determinism, nonlinearity, non-stationarity and laminarity. The complexity in critical queue conditions is further investigated by introducing two supplementary regions in the critical area before spillover occurrence. Results indicate that the supplementary information on the transitional conditions in the critical area increases the accuracy of the predictive relations between the statistical characteristics of traffic flow evolution and the occurrence of transitions.     

采用GTM方法设计的沥青混合料高温稳定性研究

针对现行的马歇尔方法不能设计出理想的沥青混合料这一问题,本文利用旋转试验机对5种不同的沥青混合料进行了优化,并对这5种不同级配类型、不同沥青用量所组成的沥青混合料进行车辙试验,分析了不同级配类型沥青混合料的车辙发展规律,以及沥青混合料动稳定度同密度和空隙率等之间的关系。试验结果表明:级配、体积参数等对沥青混合料的高温稳定性有重要影响。     

吹填淤泥自重固结性状研究

结合围海造陆软基处理工程项目,基于以界限孔隙比作为吹填淤泥落淤过程沉积与自重固结的分界点、考虑落淤后发生以自重固结为主的变形,推导吹填淤泥一维自重固结方程并编制有限差分法求解程序,进行初始压缩性、初始渗透性及初始体积分数对吹填淤泥自重固结性状的影响分析,结果表明:初始压缩性和初始渗透性的增加,明显加快颗粒体自重有效应力、体积分数的增长及孔隙比的减小,加速表面沉降及沉降速率的发展;吹填淤泥自身强度的增长、压密程度、孔隙特征和表面沉降对初始体积分数的变化极其敏感,初始体积分数的增加会减缓颗粒体自重有效应力、体积分数和孔隙比的变化,初始体积分数的减小会加速表面沉降与沉降速率的发展.     

铁路罐车容积计量比对分析

介绍铁路罐车容积计量比对方案、实施过程、比对结果,分析参比实验室的检定数据和结果。比对结果表明,各参比实验室归一化偏差的绝对值小于1,计量比对结论为满意。     

基于VB 6.0的CATIA二次开发在零件测量中的应用

针对汽车车身开发过程中重量管控,为改善单件重量手工测量统计的传统低效现象,给出单件重量的程序自动测量方法.在介绍VB编程语言及CATIA二次开发理论的基础上,给出程序自动测量的基本流程,利用VB6.0 Automation API调用内置函数GetMeasurable,实现零件的批量测量并写入EXCEL表格中为后续数据...