An Economic Approach to Allocating River Water to Estuaries in South Africa

Estuaries are last in line as a recipient of river water and for this reason they are particularly vulnerable to negative environmental impacts due to water scarcity and pollution. They only receive the runoff that has not been abstracted or prevented from reaching rivers. When this runoff is substantially reduced their functionality is undermined and they often become less attractive for recreational use. This article explores some aspects entailed in efficiently managing the allocation of water to estuaries problem and some associated problems. It is shown that efficient management requires the marginal social costs of the inflows to be brought into equivalence with the marginal social values of the inflows, and these values may be estimated, but that there are the challenges in this estimation and in linking these estimates to the welfare of the people in whom the managers of river systems are (presumed to be) interested.     

Evaluating the service requirements of dedicated container terminals: a revised IPA model with fuzzy AHP

The purpose of this article is to evaluate the service requirements of dedicated container terminals (DCTs). In this article, the service attributes (SAs) of DCTs were first discussed. A fuzzy analytic hierarchy process model was then constructed to measure the users’ perceived importance and dissatisfaction for each of the SAs. Based on these two measurements, a revised importance-performance analysis model was proposed to identify the SAs that should be improved. To validate the model, the dedicated container terminal of Evergreen Marine Corp. (EMC DCT) at Kaohsiung Port and its users were empirically investigated. With respect to the empirical results, managerial implications of the findings in improving service quality for the EMC DCT are discussed.     

Numerical prediction of the modal response of flexible cylinders in cross-flow with a current dependent form of damping

A quadratic eigenvalue problem (QEP) was posed in order to study the dynamics of flexible cylinders in cross-flow, simulating slender offshore structures such as risers, catenaries or tendons. The Euler–Bernoulli equation was used to model the structure assuming a fluid loading model, and yielding a quadratic eigenvalue problem that included a form of damping dependent not only on the structural damping itself, but also on the free stream velocity and the fluid force coefficients. We solved the QEP using the finite element method. We also derived a simplified analytical solution in this work for comparison with the QEP, however this solution does not consider changes in tension along the length of the cylinder as the QEP does. In our study, the QEP solutions were first validated against the simplified analytical solution, and also against a well-known experimental dataset obtained in 2003, in which a flexible circular cylinder model was used to model the dynamics of a riser undergoing multi-mode vortex-induced vibrations.     

Full scale ice sea trials of Korean ice breaking research vessel ‘Araon’ on the big floes near Antarctica

A speed sea trial was performed in the Amundsen Sea in February and March of 2012. The Korean ice breaking research vessel “Araon” was used to check speed performance on the big floes. Two of ice trial cases were carried out. We describe the time history of location, the engine power, and the revolutions per minute during the ice trial, and the trajectory of the ship. Additionally, the measured ice properties are considered and discussed. The ice trial results were analyzed according to variation in ice thicknesses, ice strength, propulsion power, and the speed level of the ship. Our analysis results are compared to model test results and ice trial results. A correction to the target ice thickness was used to compare the power and speed relation in the same ice thickness because it is easy to know the relative speed performance of the ship. The Hamburgische Schiffbau-Versuchs Anstalt method was applied for the correction. The speed of Araon in big floes was higher than the speed in level ice. The speed after the correction at 10 MW of power and 103 cm of ice thickness was 5.4 knots based on analysis results.     

Advanced Driver Assistance Systems from Autonomous to Cooperative Approach

Abstract

Advanced Driver Assistance Systems (ADAS) have been one of the most active areas of ITS studies in the last two decades. ADAS aim to support drivers by either providing warning to reduce risk exposures, or automating some of the control tasks to relieve a driver from manual control of a vehicle. ADAS functions can be achieved through an autonomous approach with all instrumentation and intelligence on board the vehicle, or through a cooperative approach, where assistance is provided from roadways and/or from other vehicles. In this article, recent research and developments of longitudinal control assistance systems are reviewed including adaptive cruise control, forward collision warning and avoidance, and platooning assistants. The review focuses on comparing between autonomous systems and cooperative systems in terms of technologies used, system impacts and implementation. The main objective is to achieve common understanding on ADAS functional potentials and limitations and to identify research needs for further studies.     

Impact of Everyday Weather on Individual Daily Travel Behaviours in Perspective: A Literature Review

Despite the hundreds of billions of dollars being spent on infrastructure development -- from roads, rail and airports to energy extraction and power networks to the Internet -- surprisingly little reliable knowledge exists about the performance of these investments in terms of actual costs, benefits and risks. This paper presents results from the first statistically significant study of cost performance in transport infrastructure projects. The sample used is the largest of its kind, covering 258 projects in 20 nations worth approximately US$90 billion (constant 1995 prices). The paper shows with overwhelming statistical significance that in terms of costs transport infrastructure projects do not perform as promised. The conclusion is tested for different project types, different geographical regions and different historical periods. Substantial cost escalation is the rule rather than the exception. For rail, average cost escalation is 45% (SD=38), for fixed links (tunnels and bridges) it is 34% (62) and for roads 20% (30). Cost escalation appears a global phenomenon, existing across 20 nations on five continents. Cost estimates have not improved and cost escalation not decreased over the past 70 years. Cost estimates used in decision-making for transport infrastructure development are highly, systematically and significantly misleading. Large cost escalations combined with large standard deviations translate into large financial risks. However, such risks are typically ignored or underplayed in decision-making, to the detriment of social and economic welfare.     

Examining the Political and Practical Reality of Bus-based Real Time Passenger Information

Abstract

Enhancing the bus experience through improved information provision is a key element of UK Government transport policy. Real time passenger information (RTPI) is perceived to reassure waiting passengers, to benefit the bus operator through increased revenue and the local authority, by promoting social inclusion and achieving a modal shift. RTPI also provides an important tool for operators by allowing them to monitor services and refine their schedules.

The aim of this paper is to understand the reasons for implementing RTPI in the bus sector, and to determine the key issues impacting on the likely success of such a policy. A case study approach investigates the experiences of two provincial towns in the UK. The paper suggests that, whilst it is unclear whether RTPI has resulted in an increase in bus patronage, it is considered to be most effective when combined as part of a package of measures. It is intended that the findings from the two case studies will reveal lessons of relevance to authorities contemplating the introduction of RTPI.     

Determining strategies to increase response rates in transport surveys of small shop-based businesses

Increasing representation of small business perspectives in policy research would benefit from identifying strategies to increase response rates. Despite the significance of the issue, there is inconsistent reporting amongst small business research about issues such as sampling, recruitment and survey design. Reporting on such issues may help address the under-representation of small business respondents and help reduce wasting research resources on less effective strategies. For policy matters that have the potential to disrupt how small business owners run their business, this is of particular importance. This paper reports on a survey of small businesses about changes to the transport accessibility features of a town centre that have the potential to affect the supply of car parking. Based on a review of the available literature, strategies were adopted to reduce respondent burden and maximise engagement. The paper presents an analysis of recruitment approaches in the first wave of the survey and demonstrates how the refinements to the recruitment approach were successful in achieving an increase in response rate from 40% to 47%.