站在北美港口的角度 看跨太平洋集装箱班轮航线

2004年是温哥华港务局作为第一家北美的港口获准在中国正式建立办事处的第十个年头.     

Minimizing vehicle post impact path lateral deviation using optimized braking and steering sequences

This paper investigates the optimal control of a vehicle, after a light impact during a traffic accident. To reduce the risk of secondary events, the control target is set: to minimize the maximum lateral deviation from the initial path. In previous analysis path control was achieved by the active control of individual wheel braking. The present paper examines potential benefits from the additional control of front steering angles. Numerical optimization is used to determine optimal control sequences for both actuator configurations. It is found that steering provides significant control benefits, though not for all post-impact kinematics. For all cases considered, the optimal control operates at the boundary of the control domain of available forces and moments. This domain is expanded when steering is available, and there exists an expanded range of conditions for which coupled control of yaw moments and lateral forces is the most effective control strategy. The sensitivity of vehicle response to the individual actuator controls is studied; it reveals this sensitivity is related to the actuator bandwidth and the lack of any dynamic cost in the longitudinal direction. This motivates a further analysis which includes longitudinal and lateral dynamics in the cost function. This is broadly related to real-world crash risks. Further, different versions of such cost functions are compared as a basis for implementation in a closed-loop controller.     

Land use pressures on coastal estuaries in Atlantic Canada

Abstract

The management of estuarine areas in Canada has received little attention; this is specifically the case along the Atlantic coast. This article reviews the importance of estuaries as resources and analyzes the land‐use pressures which can affect them. Specific emphasis is placed on the results of a recent study of estuaries in Atlantic Canada. The incidence of the closures of shellfish areas is used as a measure of the impact of land development on estuaries.     

Application of Learning Automata to Controller Design in Slow-Active Automobile Suspensions

This study considers a new design methodology in the context of active vehicle suspension control. The approach combines concepts from Stochastic Optimal Control with those of Learning Automata. A learning automaton effectively learns optimal control on-line in the vehicle, in an appropriate stochastic “test-track” environment. For practical application, the overwhelming advantage of this approach is that no explicit modelling is required, and considerable time savings may be expected in system development. This simulation study considers the on-line learning of optimal control in a low-bandwidth active suspension system, where control feedback is confined to a body-mounted accelerometer at each corner of the vehicle. It is shown that learning can successfully take place under a range of conditions, including the case when there is substantial transducer noise. The performance of the resulting control system is shown to depend heavily on the nature of the learning environment.     

Automated driving and autonomous functions on road vehicles

In recent years, road vehicle automation has become an important and popular topic for research and development in both academic and industrial spheres. New developments have received extensive coverage in the popular press, and it may be said that the topic has captured the public imagination. Indeed, the topic has generated interest across a wide range of academic, industry and governmental communities, well beyond vehicle engineering; these include computer science, transportation, urban planning, legal, social science and psychology. While this follows a similar surge of interest – and subsequent hiatus – of Automated Highway Systems in the 1990s, the current level of interest is substantially greater, and current expectations are high. It is common to frame the new technologies under the banner of ‘self-driving cars’ – robotic systems potentially taking over the entire role of the human driver, a capability that does not fully exist at present. However, this single vision leads one to ignore the existing range of automated systems that are both feasible and useful. Recent developments are underpinned by substantial and long-term trends in ‘computerisation’ of the automobile, with developments in sensors, actuators and control technologies to spur the new developments in both industry and academia. In this paper, we review the evolution of the intelligent vehicle and the supporting technologies with a focus on the progress and key challenges for vehicle system dynamics. A number of relevant themes around driving automation are explored in this article, with special focus on those most relevant to the underlying vehicle system dynamics. One conclusion is that increased precision is needed in sensing and controlling vehicle motions, a trend that can mimic that of the aerospace industry, and similarly benefit from increased use of redundant by-wire actuators.     

印度对中国的畏惧蔓延至港口

印度对于与中国合作的重重顾虑——最初出于安全考虑，印度政府对中国公司在该国电信行业的影响倍感忧虑——如今这种安全忧虑已经蔓延到了港口运输业。Gordon Feller为您报道。[编按]     

Giving a direction to port regionalisation

As theoretical approaches to port development have advanced over the years, the role of the inland terminal has attracted increasing focus, particularly under the framework of port regionalisation. This paper will explore port regionalisation in different contexts through a greater focus on the drivers and direction of a number of inland terminal development strategies.The paper will build on previous work by combining inland terminal taxonomies and the theory of directional development with traditional port development models. Regionalisation strategies will be compared and contrasted through examples derived from field work undertaken in Europe and the USA. The results contribute towards a disaggregation of the process of port regionalisation, revealing different levels of integration and cooperation observed in different location splitting models. In this way, different strategies will be elucidated, enabling further exploration and more nuanced understanding of the institutional aspects of spatial development.     

Short-sea shipping potentials in Central America to bridge infrastructural gaps

This paper addresses the situation of transport infrastructure in Central America, which poses issues of insufficiency, high-costs and lack of an integrated vision in a geographic region that is exposed to vulnerabilities due to its geological, geomorphologic and climatic conditions. The major efforts for regional integration with joint infrastructure in place seem to meet the criteria of high prioritization on ground transport and non-diversification of risk. This paper features the characteristics of the area and the potentiality of short-sea shipping to cover infrastructure deficits and the need for a more integrated planning of transport infrastructure services with better conditions to improve the regional economy competitiveness and the economic growth.     

Restructuring land transport in New Zealand

Restructuring of governmental activities in New Zealand calls for public enterprises to operate in competitive environments. This has created problems for highways and urban passenger transport. Whereas the national airline has been privatized and railways corporatized, legislation for land transport has created a Crown agency that is expected to operate commercially within funding and policy constraints. The problems are assessed as Transit New Zealand attempts to allocate state funds between competing projects using commercial criteria. New roles have been legislated for regional agencies and local governments: they are expected to either privatize service delivery or create public corporations to maintain highways and operate passenger transport. Principles underlying restructuring are examined, and suggestions are made on how agencies might take advantage of opportunities.