水下爆炸气泡激起的船体鞭状运动

本文揭示了水下非接触爆炸产生的气泡脉冲缴起细长形船体鞭状响应运动的现象。考虑到了水下爆炸气泡的脉冲多次性,迁移和水面效应,计算结果与弹性船模试验结果进行了对比,符合程度令人满意。     

大连港大窑湾一期工程后六泊位工作船码头工程模型试验

介绍工作船码头采用轻型空心方块结构型式的断面模型试验方法、测试内容及试验结果,为设计提供依据。     

D-S证据理论在多传感器融合中的应用

详细介绍了Dempster-Shafer证据理论,介绍了它在多传感器融合(MSF)中的应用,并举了一个具体的例子,实验结果验证了其有效性。     

A two-phase model for dry port location with an application to the port of Dalian in China

This paper provides guidance for an optimal and reasonable dry port layout for the port of Dalian in China. We present a two-phase framework on the location of dry ports, which solves the selection of candidate inland cities and optimal dry port location choice, respectively. Fuzzy C-Means Clustering is applied to select alternative cities in the vast hinterland of the seaport of Dalian, with a view to identify evaluation factors that affect the location selection decision. A cost-minimisation linear programming solution is proposed, with the aid of a genetic algorithm, to choose the optimal location as well as capacity level among the candidate inland cities.     

The role of volume-delay functions in forecasting and evaluating congestion charging schemes: the Stockholm case

This paper uses observations from before and during the Stockkholm congestion charging trial in order to validate and improve a transportation model for Stockholm. The model overestimates the impact of the charges on traffic volumes while at the same time it substantially underestimates the impact on travel times. These forecast errors lead to considerable underestimation of economic benefits which are dominated by travel time savings. The source of error lies in the static assignment that is used in the model. Making the volume-delay functions (VDFs) steeper only marginally improves the quality of forecast but strongly impacts the result of benefit calculations. We therefore conclude that the dynamic assignment is crucial for an informed decision on introducing measures aimed at relieving congestion. However, in the absence of such a calibrated dynamic model for a city, we recommend that at least a sensitivity analysis with respect to the slope of VDFs is performed.     

An integrated framework for embedding large-scale dynamic traffic assignment models in advanced traveler information systems

In recent years, increasing attention has been drawn to the development of various applications of intelligent transportation systems (ITS), which are credited with the amelioration of traffic conditions in urban and regional environments. Advanced traveler information systems (ATIS) constitute an important element of ITS by providing potential travelers with information on the network's current performance both en-route and pre-trip. In order to tackle the complexity of such systems, derived from the difficulty of providing real-time estimations of current as well as forecasts of future traffic conditions, a series of models and algorithms have been initiated. This paper proposes the development of an integrated framework for real-time ATIS and presents its application on a large-scale network, that of Thessaloniki, Greece, concluding with a discussion on development and implementation challenges as well as on the advantages and limitations of such an effort.     

Instantaneous communication throughputs of vehicular ad hoc networks

Vehicular ad hoc networks (VANETs) formed by connected vehicles in a traffic stream could be applied to improve safety, mobility, and environmental impacts of a transportation system. In this paper, we present analytical models for the instantaneous communication throughputs of VANETs to measure the efficiency of information propagation under various traffic conditions at a time instant. In particular, we define broadcast and unicast communication throughputs by the wireless channel bandwith multiplied by the average probabilities that one vehicle is a successful receiver and sender in a VAENT, respectively. With a protocol communication model, we derive formulas to determine the probabilities for an equipped vehicle to be a successful broadcast receiver and a successful unicast receiver/sender, and obtain broadcast and unicast throughputs along discrete and continuous traffic streams. We further examine the impacts on communication throughputs of the transmission range and the interference range of dedicated short range communication devices as well as the market penetration rate of equipped vehicles and the percentage of senders. Finally, we investigate the influence of shock waves on communication throughputs.     

基于交通信息的电动汽车制动策略及仿真

为了提高滑行能量回收经济性和踏板制动安全性、舒适性,基于交通信息,提出了电动汽车(EV)制动协调策略。分析了滑行制动的经济性,由交通信息和汽车行驶状态确定滑行制动强度;由道路信息和前方车辆信息建立汽车安全距离模型和碰撞预警策略,利用预警信息对滑行制动和踏板制动强度进行协调。对本策略进行仿真验证。结果表明:利用交通信息的滑行策略,在通行良好工况下综合能耗减少1.1%,拥堵工况下减轻驾驶员的制动疲劳;预警和协调策略避免了频繁预警,减小了紧急避撞触发几率。因此,利用交通信息能够辅助驾驶员进行更加合理的制动。     

基于Halcon及VS的动车组制动闸片厚度自动识别模块

研究基于图像处理和模式识别的动车组闸片厚度自动识别模块,解决动车组制动时因闸片过薄而导致的车轮迅速升温,甚至引发不安全状态的问题.该模块可实现动车组通过时自动检测,即自动拼图、图像预处理、模型定位及制动闸片厚度计算,并对厚度小于一定数值的闸片进行自动报警.通过大量实验和测试表明,该模块可以有效地计算闸片的厚度,具有很好...     

考虑季节性温湿变化的混凝土桥梁徐变计算模型研究

为研究温湿变化对混凝土桥徐变效应的长期影响,建立考虑季节性温湿变化的混凝土桥徐变计算模型.该模型以卢志芳模型为基础,选取我国6个典型温湿度特征城市,基于徐变系数非减原则,建立温湿度时变函数,利用多项式累加和积改进卢志芳模型,得到改进徐变模型.将该模型应用于某预应力混凝土连续梁桥(假设该桥分别位于6个城市)10年徐变效应...