Identifying the early adopters of alternative fuel vehicles: A case study of Birmingham,United Kingdom

The transport sector has been identified as a significant contributor to greenhouse gas emissions. As part of its emissions reduction strategy, the United Kingdom Government is demonstrating support for new vehicle technologies, paying attention, in particular, to electric vehicles.Cluster analysis was applied to Census data in order to identify potential alternative fuel vehicle drivers in the city of Birmingham, United Kingdom. The clustering was undertaken based on characteristics of age, income, car ownership, home ownership, socio-economic status and education. Almost 60% of areas that most closely fitted the profile of an alternative fuel vehicle driver were found to be located across four wards furthest from Birmingham city centre, while the areas with the poorest fit were located towards the centre of Birmingham. The paper demonstrates how Census data can be used in the initial stages of identifying potential early adopters of alternative vehicle drivers. It also shows how such research can provide scope for infrastructure planning and policy development for local and national authorities, while also providing useful marketing information to car manufacturers.     

Port system evolution – the emergence of second-tier hubs

Some evidence has emerged of second-tier hubs inserting themselves between hubs and feeder ports, producing a new hierarchy of port networks. This article aims to establish the dynamics of this process based on illustrative cases in Asia, South America, and Europe. Findings reveal spatial factors to include a cluster of small ports with minimal sailing distance within a given range, suitable channel and berth depth, and ideally high capacity inland links. From the economic perspective, demand-side factors include a local captive market and aggregated demand to be captured from other ports, while supply-side factors include diseconomies of scale at traditional hubs, an increase in direct services, an increase in large feeder vessels calling from first-tier hubs which are then transhipped to smaller feeders for serving local ports, and an increase in overland servicing of local smaller ports. From a strategic perspective, vertical and horizontal integration in the shipping sector has produced extensive network economies, whereby shipping lines look to create group-specific port hierarchies, enhanced in the presence of aggressive management strategies and supportive policies. This finding suggests that proactive port stakeholders can in certain circumstances seize the opportunity to capture this role within their port range.     

钢结构空心截面连接杆件有效长度系数的初步研究

介绍了在钢桥连接系采用空心截面杆件时,连接系与主梁的连接问题中,偏心连接板有效长度系数的分析和确定.有效长度系数对于这种连接的设计起关键作用.在分析过程中,运用了NASTRAN有限元分析平台对实际问题进行了建模计算,并对结果进行了比较分析.从结果中,我们发现,连接板尺寸的变化可以得出不同的破坏荷载,从而推导出不同的有效长度系数.使用较长的连接板可以得出较小的有效长度系数.板厚的增大使有效长度系数明显增大.通过本文的几个模型分析结果,我们发现,有效长度系数取值在1.0～2.0之间.     

Rigor and Representativeness in Marine Protected Area Design

Virtually all marine conservation planning and management models in place or proposed have in common the need for improved scientific rigor in identifying and characterizing the marine habitats and processes encompassed. An emerging central theme in the last few years has been the concept of representativeness, or representative systems of marine protected areas (MPAs). Representativeness and similar terms are used in two distinct senses in current literature, leading to considerable confusion. Definitions of these terms as they are currently used are provided. The habitat classification and mapping needed to incorporate considerations of representativeness into MPA planning must logically be carried out at the same scale at which management occurs. Management of highly protected areas is found to occur almost exclusively at local scales or finer, independent of the reservation model or philosophy employed. Current techniques for cost-effective surveying of marine areas are discussed. The emerging field of remote videography, in some cases linked with acoustic discrimination sensors, can provide quantitative data on real biological distributions. Such data lend themselves well to robust multivariate analysis in deriving habitat maps at scales relevant to managers, as a basis for assessing and planning for representation in MPA design.     

Marina inventory and berthing supply projections: Mississippi's Gulf Coast

Abstract

The location as well as pace of marina development is a major issue in current coastal zone management. The supply and demand for marinas providing certain services in specific locations are growing and must be met. At the same time the environmental integrity of the coastal zone must be maintained against the many possible impacts of marina development. Compounding these problems from the view of both the developer and coastal zone manager is the absence of necessary data and accepted methodologies for estimating future supply needs for marine berthing. This paper describes a multi‐focii approach to the establishment of an information base and marina supply projections for the Mississippi Gulf Coast. Data on existing marina types, services, and facilities are obtained via fieldwork; future marina slip supply needs are estimated using a combination of several techniques and data sources. The study serves two purposes. First, it initiates the basis for improved management of marina development on Mississippi's Gulf Coast. Second, on a more theoretical level, it stimulates research toward developing and validating supply and demand projection techniques for marinas.     

Port-centric logistics,dry ports and offshore logistics hubs: strategies to overcome double peripherality?

Scotland's low accessibility is reflected in the limited share of Scottish unitised freight traffic coming through Scottish ports. This paper will discuss site development strategies to overcome Scotland's double peripherality (i.e. both physically and institutionally) by restructuring transport chains of large shippers through new corridors. Three competing logistics concepts will be discussed, beginning with the existing load centre terminal that provides direct access to the distant main ports. Second, port-centric logistics based at Scottish ports, and finally, offshore port-centric logistics utilising maritime links to a port-based distribution centre in Zeebrugge. The paper has two interlinked aims. First, to provide a firm theoretical grounding for recent maritime transport geography concepts, which has been lacking in the literature. This will be achieved by examining peripherality and responses to this by states at different scales, thus exploring how the three concepts in this paper can be viewed as attempts at spatial fixes of mobile capital. The second aim develops out of the first, and will explore how the perspective of space is treated in maritime geography as compared with other areas of geography. As a result, the paper pursues a cross-disciplinary approach by utilising theory from economic geography and political geography.     

盘点保时捷对大众控股的深远意义

控股大众的现实意义2005年9月保时捷宣布收购大众的18．5%股权。从而宣布两家公司的关系回到了费迪南德先生开发大众甲壳虫车的30年代。围绕Ferdinand Piech(费迪南德·保时捷的孙子)的角色问题,这一控股行动倍受股东和金融机构的质疑。     

A Comparison of Adaptive LQG and Nonlinear Controllers for Vehicle Suspension Systems

A design feature of many computer-controlled suspension systems, is their ability to adapt control law parameters to suit prevailing road conditions. Here, for systems employing high bandwidth actuators and state variable feedback control, the benefits of such adaptation are shown to be at best marginal. An optimal adaptive LQG system is compared with a fixed structure nonlinear feedback controller in the context of a simple quarter-vehicle suspension model. Performance comparisons are made, and trends considered under more realistic conditions. In consequence the overall usefulness of this type of adaptation is called into question.     

Travel mode choice and travel satisfaction: bridging the gap between decision utility and experienced utility

Over the past decades research on travel mode choice has evolved from work that is informed by utility theory, examining the effects of objective determinants, to studies incorporating more subjective variables such as habits and attitudes. Recently, the way people perceive their travel has been analyzed with transportation-oriented scales of subjective well-being, and particularly the satisfaction with travel scale. However, studies analyzing the link between travel mode choice (i.e., decision utility) and travel satisfaction (i.e., experienced utility) are limited. In this paper we will focus on the relation between mode choice and travel satisfaction for leisure trips (with travel-related attitudes and the built environment as explanatory variables) of study participants in urban and suburban neighborhoods in the city of Ghent, Belgium. It is shown that the built environment and travel-related attitudes—both important explanatory variables of travel mode choice—and mode choice itself affect travel satisfaction. Public transit users perceive their travel most negatively, while active travel results in the highest levels of travel satisfaction. Surprisingly, suburban dwellers perceive their travel more positively than urban dwellers, for all travel modes.