The past,present, and future of urban cable propelled people movers

The evolution of urban cable propelled people mover technology from the early 1800′s through the 1990′s is reviewed, with emphasis on systems developed since 1980. Technologies can be classified by the means of vehicle support and the type of service provided. The simplest systems serve as shuttles moving back-and-forth between a pair of terminal stations; more complex systems feature vehicles which are launched continuously at short headways. Advances have occurred in the design and aesthetics of guideways, vehicle operating speed, the spectrum of capacities available, and automated features. The characteristics of the individual systems in urban environments throughout the world are described.     

Intersection traffic energy management system (ITEMS): formulation and validation

Urban transportation and traffic face significant challenges as cities continue to grow. Traffic intersections present unique challenges for city planners. Several studies have proposed diverse approaches to managing intersection traffic. However, these typically fail to reduce both energy and trip time for all vehicles involved. This paper proposes the intersection traffic energy management system (ITEMS). By using speed regulation of two vehicles approaching an intersection on crossroads, ITEMS is able to resolve intersection conflicts. This obviates the need for either vehicle to stop. Two-vehicle and four-vehicle scenarios were simulated. It was found that ITEMS reduced the total energy about 22% and the trip time across the intersection by almost 16% for every scenario compared to a traditional fixed-timed traffic light intersection. ITEMS was also found to be superior than always giving a green light to urban transit vehicles. Furthermore, with ITEMS, the energy and trip time of each vehicle in the scenario was reduced when compared to other strategies.     

A New Method for Accurately Estimating the Weight of Moving Vehicles Using Piezoelectric Sensors and Adaptive-footprint Tire Model

Summary This paper presents new methods for estimating the axle weight of a moving vehicle, using two piezoelectric sensors and adaptive-footprint tire model. It is more difficult to weigh vehicles in motion accurately than to weigh standing vehicles. The difficulties in weighing moving vehicles result from sensor limitations as well as dynamic loading effects induced by vehicle/pavement interactions. For example, two identical vehicles with the same weight will generate sensor signals that differ in the shape and the peak value, depending the tire pressure, vehicle speed, road roughness, and sensor characteristics. This paper develops a method that is much less sensitive to these variable factors in determining the axle weight of a moving vehicle. In the developed method, first the piezoelectric sensor signal is reconstructed using the inverse dynamics of a high-pass filter representing the piezoelectric sensor. Then, the reconstructed signal, is normalized, using the nominal road/tire contact length obtained using an adaptive-footprint tire model, and then integrated. Experiments are performed with 3 vehicles of known weight ranging from 1,400 kg to 28,040 kg. The developed method is compared to two other algorithms. Results show that the developed method is most consistent and accurate.     

Maritime security in the European Union—empirical findings on financial implications for port facilities

To address the maritime security issue, the IMO Diplomatic Conference adopted in December 2002 the International Ship and Port Facility Security (ISPS) Code. The European Union fully agreed with its contents; Regulation (EC) No. 725/2004 transposes in Community Law the associated rules, which came into force on 1 July 2004. Interesting questions from an EU-policy point of view are then: What are the additional costs associated with the implementation of security regulations by port facilities (here in particular terminals) in EU-member states? Moreover, how are these additional costs being recovered by port facilities? Another inter-related question is: are there any subsidies involved in the cost recovery? The present paper addresses these questions with the presentation of the main results of an explorative empirical study on maritime security-related costs and their financing in EU-member states. Furthermore, a number of topics are recommended for further study on maritime security costs and financing and associated (EU) regulations.     

On the feasibility of the optical steering wheel sensor: Modeling and control

This paper discusses the development of a system model for the wireless steering wheel angle sensor and steering wheel system for the evaluation of the steer by wire system in a vehicle dynamic system. The steering wheel sensor is a wireless, contact-less sensor utilizing an optical medium for angle detection. The optical medium is operated based on a photodiode and photo-detector head. A reflecting disc or code-wheel, working similar to a compact disc, is used to reflect the light from the photodiode back to the photo-detector. The beam is reflected based on the content in the reflective disc to measure the relative angle through a micro-controller. The proposed wireless steering sensor and steer by wire system is modeled using the Matlab/Simulink and their performance is investigated to evaluate the steering response, vehicle dynamics, and steering feel of the system. Finally, the feasibility of the proposed system is discussed based on the developed model and simulation results.     

桥梁水毁研究综述

近年来，桥梁水毁日益频发，已成为桥梁倒塌失效的首要因素。从冲刷、洪水2类最主要的水文因素出发，充分结合历史数据，分析并对比其对桥梁水毁的影响程度与规律；并按2类水文因素所对应的不同桥梁倒塌失效模式，对桥梁水毁现有的研究工作和方法进行总结归纳；最后，聚焦实桥应用，对现有桥梁水毁监测和诊治手段进行全面梳理。综述可得以下结论：①冲刷是导致桥梁水毁的最主要因素，所致失效桥型以桁架桥、梁桥、拱桥为主，桥梁服役时间、结构安全状态、年平均径流量均与桥梁所受冲刷程度存在较强相关性；②冲刷坑空间形态数值仿真与试验结果仍有一定差距，其泥沙模型缺少考虑床沙级配的影响，经验公式法尚需突破计算维度的局限性，完善考虑时间因素和黏性土的冲刷深度预测；③现阶段洪水波流竖向升力计算公式较少考虑脉动压力，浪荷载水槽试验尚未完全探明波浪特性与作用力间的联系，桥梁可靠度研究多见以冲刷为主的多灾害下联合效应计算，仍缺少波流、浪力作用与地震动水作用等其他灾害联合作用的深入探讨；④桥梁抗水目前仍局限于流场与结构域的独立研究，未见不同水文因素下基于结构域-流场多场耦合的桥梁失效模式分析；⑤雷达、声波以及潜水员水下检测是现阶段桥梁冲刷主流监测方式，桥梁冲刷动力识别适用于复杂环境下大规模、区域性桥梁检测，但仍有待进一步的应用研究，而既有桥梁水毁诊治手段在具体实施时需因地制宜，避免反而加剧水文病害。     

Effects of Tank Shape on the Roll Dynamic Response of a Partly Filled Tank Vehicle

The directional response and roll stability characteristics of a partly filled tractor-semitrailer vehicle, equipped with various cross-section tanks, are investigated as functions of fill volume and steer inputs. The tank-vehicle combination is analytically modeled upon integrating a quasi-static roll plane model of a partly filled tank of generic cross-section with a three-dimensional directional dynamic model of a five-axle tractor-semitrailer vehicle, assuming constant forward speed. The vehicle model is analyzed for different cross-sections of partly filled tanks, including circular, modified-oval and two optimal cross-sections. The directional response characteristics of the vehicle are evaluated to study the influence of partial-fill condition, steering maneuver, and vehicle speed on the roll dynamic performance of the tank cross-section and the vehicle. A comparison of the response characteristics, in terms of variations in cargo c.g. shift and roll mass moment of inertia, roll angle, lateral acceleration and yaw rate of the trailer sprung mass, revealed that the optimal tank geometry yields considerably less variations in the cargo c.g. coordinates and can thus significantly enhance the directional response and roll stability characteristics of partly-filled tank vehicles.     

Prediction of steel plate deformation due to triangle heating using the inherent strain method

In a shipyard, line heating and triangle heating are two major processes carried out by skilled workers to form curved plates in various shapes under various heating conditions. There have been many studies on line heating, but triangle heating has rarely been studied owing to its complicated heating process with irregular multiheating paths and highly concentrated heat input. Triangle heating is the most labor-intensive job. Hence, it is essential for most shipyards to study the automation, as well as the improvement, of the triangle heating process in order to increase hull-forming productivity. In this study, a pioneering attempt to simulate triangle heating was made. A circular disk-spring model is proposed as an analysis model for the elastoplastic procedure of triangle heating, and the inherent strain method is also used to analyze the deformation of plates. The results of the simulation were compared with those of experiments and showed good agreement. It is shown that the present approach and the model used in this study are effective and efficient for simulating triangle heating for the steel plate forming process in shipbuilding.