Hydrodynamic derivatives investigation of unconventionally arranged pusher-barge systems

Unconventional arrangements of pusher-barge systems were studied in this paper. Pusher-barge systems consisting of 4, 6, and 8 barges with one pusher were tested in various combinations. Captive model testing was performed on the various combinations at the Hiroshima University towing tank. Hydrodynamic derivatives of the systems were obtained from the model test data by using the least-square analysis method. For asymmetric conditions, the hydrodynamic derivatives and N′_ββ were added to the force and moment equations in order to obtain better fitting of the least-square curves. Motion equations were modified to cover the asymmetric cases of pusher-barge systems with lateral force and yaw moment due to the asymmetry arrangement. Turning simulations (with 20° sudden angle change) were carried out and a comparison of advance distance and tactical diameter made. An erratum to this article can be found at     

Development of and prospects for cruising in Europe

This paper evaluates the development of prospects for cruising in Europe. It examines this within the broad framework of economic theory and maritime economics. Initially, the market structures and relationships applicable to cruising are considered with particular attention being paid to the linkages between the shipping markets and tourism and leisure. This conceptual analysis suggests that whilst cruising has a strong shipping element it does not fall exclusively within the classic framework of maritime economics but draws from both shipping and tourism and leisure. For reasons of clarity, a number of definitions are also provided covering maritime tourism and leisure, cruising, and supply and demand, as it relates to cruising. Following this, an overview of the cruise industry is included. This focuses primarily on the growth in the demand both world wide and at regional level. In particular, the analysis places the development of cruising in Europe in market perspective. Subsequently, the development of cruising in the UK is examined as a case study. Initially, UK market growth is analysed and it can be seen that the UK is now the second largest cruise market in the world after North America. Projections of the growth in UK demand to 2003 are also provided. The growth in supply is also studied and the UK targeted fleet is identified. In addition, the question of ownership is addressed. The prospects of employment for UK seafarers within the cruise industry are also considered and results obtained from the analysis suggest that it should be possible to increase the participation of UK and other European seafarers within the cruise industry at all levels and in all departments. In the final section of the paper, the position of UK ports as terminals and destinations is evaluated. It is concluded that the fundamentals of the cruise business remain strong, and continued growth by the industry should be possible for the foreseeable future.     

Urban highway congestion

This article examines urban highway congestion pricing in the instance in which it is not possible to levy a congestion toll on a major portion of the urban road system. This case is pertinent because of technical and/or political constraints. The article uses economic theory and numerical examples to show that the optimum second-best toll can vary appreciably from the optimal tolls in a regime in which efficient tolls can be imposed on all routes.     

高速铁道车辆的主动稳定性系统

介绍了高速铁道车辆的主动稳定性控制系统.利用整车滚动试验台对稳定性控制器的性能进行了试验.     

ROAD KILL CARPET

这地毯血腥了点,其实它很有爱心。由于出品方是设计了树枝U盘(Wooden USB Stick)的荷兰Studio OOOMS,我很相信OOOMS这次又是在发挥对自然的热爱——地毯上那只血肉模糊的狐狸,是设定为被飞驰的汽车谋杀而死。那么你不妨将这地毯送给你粗心大意而又迷恋疾速驾驶的朋友,提示他以后通过野生动物栖息地的时候,将车速放慢些,眼睛睁大些。当然,如果他听取了意见,你也不必反对他拿狐狸尸体的那部分当做枕头,躺在这地毯上打盹。2009年春季上市,纯手工,纯羊毛制造。尺寸:165×240cm/65×94.5inch     

Workshop report - A successful contractual setting

Successful public transport service contracts can be judged against procedural and outcome criteria, located within an integrated strategic, tactical and operational level framework for planning and delivery. Clear goal setting at the strategic level sets the basis for supportive tactical system planning and for service delivery that meets goals. The workshop considers relevant success criteria and key matters that need to be resolved for their achievement. Market growth potential and the governmental attitude to supporting service growth are important issues shaping the contractual environment. The growing interest in negotiated performance-based contracts and the role of trust between the operator and the authority are also matters for particular attention.     

A hazard-based approach to modelling the effects of online shopping on intershopping duration

Despite growing prevalence of online shopping, its impacts on mobility are poorly understood. This partially results from the lack of sufficiently detailed data. In this paper we address this gap using consumer panel data, a new dataset for this context. We analyse one year long longitudinal grocery shopping purchase data from London shoppers to investigate the effects of online shopping on overall shopping activity patterns and personal trips. We characterise the temporal structure of shopping demand by means of the duration between shopping episodes using hazard-based duration models. These models have been used to study inter-shopping spells for traditional shopping in the literature, however effects of online shopping were not considered. Here, we differentiate between shopping events and shopping trips. The former refers to all types of shopping activity including both online and in-store, while the latter is restricted to physical shopping trips. Separate models were estimated for each and results suggest potential substitution effects between online and in-store in the context of grocery shopping. We find that having shopped online since the last shopping trip significantly reduces the likelihood of a physical shopping trip. We do not observe the same effect for inter-event durations. Hence, shopping online does not have a significant effect on overall shopping activity frequency, yet affects shopping trip rates. This is a key finding and suggests potential substitution between online shopping and physical trips to the store. Additional insights on which factors, including basket size and demographics, affect inter-shopping durations are also drawn.     

Resilience and accessibility of Swedish and Dutch municipalities

Recent years have shown a rising popularity of the concept of resilience—both theoretically and empirically—in complex systems analysis. There is also a rising literature on resilience in the transport and spatial-economic field. The pluriform interpretation of resilience (e.g., engineering vs. ecological resilience) is related to methodological differences (e.g., stability in dynamics vs. evolutionary adaptivity). But in all cases the fundamental question is whether a complex system that is subjected to an external shock is able to recover, and if so, to which extent. The present paper [Based on presentation from cluster 6 (Accessibility) of the Nectar 2015 conference in Ann Arbour, USA.] aims to add a new dimension to resilience analysis in spatial systems, by addressing in particular the relationship between spatial accessibility at a municipality level and the resilience outcomes of the spatial system concerned. It does so by investigating to which extent accessibility of Swedish and Dutch municipalities has mitigated the local shock absorption from the recent economic recession. In our study the shock absorption capacity of municipal accessibility is estimated by analysing the relevant resilience indicators for the period concerned. In this context, conventional resilience indicators based on either multivariate complex data (in particular, the Foster Resilience Capacity Index) or employment data (in particular, the Martin Resilience-Employment Index) are confronted with spatial connectivity data based on local accessibility measures, so that geographical mobility may be regarded as one of the shock-mitigating factors. The empirical analysis is carried out for two countries which have both proven to be rather shock-resistant during the recent economic crisis, viz. Sweden and The Netherlands. Clearly, the geographical structure of these countries forms a sharp mutual contrast, viz. a spatially dispersed economy with a few distinct urban concentrations versus a spatially dense economy with one major metropolitan centre (the Randstad), respectively. Our experiments are carried out for the 290 municipalities in Sweden and 40 COROPs in The Netherlands. Our research findings show relevant and new insights into differences in the local recovery potential in Sweden and The Netherlands.     

Incorporating online shopping into travel demand modelling: challenges,progress, and opportunities

There is a large body of literature, spanning multiple disciplines, concerned with the relationship between traditional (physical) shopping and associated travel behaviour. However, despite the recent rapid growth of digital retailing and online shopping, the impact on travel behaviour remain poorly understood. Although the issue of the substitution and complementarity between conventional and virtual retail channels has been extensively explored, few attempts have been made to extend this work so as to incorporate virtual retail channels into modelling frameworks that can link shopping and mobility decisions. Here, we review the existing literature base with a focus on most relevant dimensions for personal mobility. How online activity can be incorporated into operational transport demand models and benefits of such effort are discussed. Existing frameworks of shopping demand are flexible and can, in principle, be extended to incorporate virtual shopping and the associated additional complexities. However, there are significant challenges associated with lack of standard ontologies for crucial concepts and insufficiencies in traditional data collection methods. Also, supply-side questions facing businesses and policy-makers are changing as retailing goes through a digital transformation. Opportunities and priorities need to be defined for future research directions for an assessment of existing tools and frameworks.     

I can’t believe your attitude: a joint estimation of best worst attitudes and electric vehicle choice

The number of conventionally fuelled motor vehicles in use is increasing worldwide despite warnings about finite fossil fuel and the detrimental impacts of burning such fuels. While electric vehicles, the subject of much research, generate far less emissions and offer the potential for power from renewable sources, they are yet to significantly penetrate the market. Tangible barriers such as price and vehicle range still exist, but consumer attitudes also drive behaviour. This paper examines attributes in a framework relatively new to transportation and energy policy; best–worst scaling. This method is widely considered an improvement over traditional methods of eliciting attitudes and beliefs, where respondents select attitudes they find best or worst from a set of attitudinal statements. To avoid potential endogeneity bias, we jointly model attitudes and choice for the first time with best–worst data. It is found that energy crisis, air quality and climate change concerns influence behaviour with respect to vehicle range and that travel behaviour change and forms of government incentives are needed influences on behaviour with respect to vehicle emissions. It is argued that correctly modelling attitudes reduces the error term of the vehicle choice model and provides policy makers with an improved lens for assessing behaviour. Additionally, the methods described within can easily be adapted to other policy scenarios.