轨道交通站点开发利益影响范围研究

利用零售力法则计算轨道站点被城市各中心吸引的概率,并利用可达性指标计算各站点在单中心影响情况下的轨道站点影响范围,结合以上两模型确定轨道站点开发利益影响范围计算模型。该模型能够用于城市多中心情况下轨道站点开发利益影响范围及相邻站点间影响范围分界线的计算,并能为轨道沿线土地利用开发、交通接驳设施设计以及轨道交通开发利益还原提供技术支持。     

冲击碾压补强技术在公路高液限土路基填筑中的应用

在公路建设的过程中,如何有效地降低工后沉降、控制路基总沉降量一直是施工中的重点.为此,三边形冲击压路机因具有很多优势而得以广泛应用.以某高速公路为例,对公路高液限土路基填筑中冲击碾压补强技术的特点及施工方法进行了探讨,以促进该技术的推广应用.     

基于贝叶斯网络的交通事件持续时间预测

随着数据采集手段的不断提高和相关研究技术的发展,基于数据挖掘的模型逐渐成为交通事件持续时间研究的主要方向。根据荷兰交通部门提供的交通事件采集数据,进行分类和预处理,观察事件持续时间的频数图,并根据相关的研究按照事件典型的类别把采集的数据进行分类。使用主成分分析和逐步回归提取出显著性的影响因子,利用数据挖掘软件WEKA建立贝叶斯网络模型,用数据集中80%的数据进行学习建模,20%的数据作为测试集来检测模型的预测效果,并做出性能评价。实验结果表明,与同类数据集的其他预测方法相比,贝叶斯网络模型对于变数众多,随机性特别大的交通事件,预测精度较高,证明贝叶斯网络模型的算法是具有一定优越性和实用价值。     

Jointly optimizing cost, service, and environmental performance in demand-responsive transit scheduling

In certain fleet systems, the environmental impacts of operation are, to some extent, a controllable function of vehicle routing and scheduling decisions. However, little prior work has considered environmental impacts in fleet vehicle routing and scheduling optimization, in particular, where the impacts were assessed systematically utilizing life-cycle impact assessment methodologies such as those described by the Society of Environmental Chemistry and Toxicology. Here a methodology is presented for the joint optimization of cost, service, and life-cycle environmental consequences in vehicle routing and scheduling, which we develop for a demand-responsive (paratransit or dial-a-ride) transit system. We demonstrate through simulation that, as a result of our methodology, it is possible to reduce environmental impacts substantially, while increasing operating costs and service delays only slightly.     

Assessment of economic impacts from unexpected events with an interregional commodity flow and multimodal transportation network model

Loss and damage caused by unscheduled events, especially earthquakes, have sudden and significant impacts not only on the region’s economy where the event occurs but also on other regions. The New Madrid Seismic Zone, located in the center of the United States, could have great impacts on economic activities related to this area, if a major earthquake occurred. Based on the 1993 US Commodity Flow Survey [US Commodity Flow Survey, 1993. Available from: <http://www.bts.gov/ntda/cfs/prod.html>], more than 42% of total commodity flows in the US are related to the greater Midwest, which includes the New Madrid Seismic Zone. If a catastrophic earthquake occurred in this area, the indirect damages could spread far beyond the region, and could have sizable impacts on other regions. A model of interregional commodity flows, incorporating regional input–output relationships, and the corresponding transportation network flows, was applied to assess the economic impacts of such an unexpected event. The economic impacts from the event are described for three hypothetical scenarios, analyzing the magnitude and the extent of the direct and indirect impacts. These analytical results may be used to propose strategic management of the recovery and reconstruction efforts after the event.     

Д形圆柱体大角度撞水载荷计算及缓冲问题的研究

一种Д形圆柱体底部金属结构在大角度高速入水时遭受破坏,解决该问题对某工程活动具有重要意义。根据KornhauserM提出的数学模型,对该圆柱体入水载荷进行预报计算并对缓冲问题进行分析,提出了在不改变Д形圆柱体结构的情况下,使用硬质聚胺酯泡沫塑料(RPUF)作缓冲层的方案,解决了工程中遇到的难题。     

摩擦桩竖向承载力计算方法研究

研究目的：解决现行桩基竖向承载力计算方法与桩-土体系的竖向变形相互独立的问题。 研究方法：首先，通过分析桩-土体系的变形机理得出合适的荷载传递函数模型；其次，根据桩-土体系的变形协调原则对桩基础的竖向承载力进行分析研究。 研究结果：针对现行桩基竖向承载力计算方法的不足，提出了一种与桩-土体系竖向变形相协调的计算方法。 研究结论：以变形协调原则与荷载传递法为基础推导的桩基承载力计算方法，能够解决桩基竖向承载力与竖向位移计算各自独立这一矛盾，满足工程设计要求。     

舰艇电磁兼容性和电磁干扰抑制技术

对电磁兼容性的一般概念进行了讨论,分析了电磁兼容的三个因素,并对舰艇电磁兼容性设计提出了初步的思路,解决舰艇电磁干扰问题的最好办法进行电磁兼容性设计和采取确当的电磁干扰抑制技术。     

港口建设项目环境影响经济评价流程的建立

从法律和理论层面分析了建立港口建设项目环境影响经济评价流程的必要性,确定了需要进行环境影响评价的港口的时空边界;给出了上述边界内水环境影响因子、大气环境影响因子、声环境影响因子和土壤环境影响因子的具体项目;在此基础上构建了港口建设项目环境影响经济评价流程。所得结果将有助于形成绿色GDP核算体系下的港口建设项目国民经济评价。     

冲击式水轮机水电站大波动过渡过程研究

针对单喷嘴冲击式水轮机,在已成熟的混流式水轮机水电站过渡过程计算理论的基础上,引入折向器的调节因素,提出了依据出力求解大波动过渡过程求解的方法,并以一个工程实例为依托,通过计算验证了折向器方程及两种大波动计算方法的合理可靠性。