Tonnage tax: is it working?

The introduction of the tonnage tax for shipping companies has been a response to the declining fleets in many European countries. There are strategic and commercial reasons why a maritime presence is desirable, not least of which is to maintain an important skill base. Although regimes have differed they all offer some form of preferential rates of tax for those ships on the register. In certain cases this tax subsidy has been linked to a requirement to train seafarers, notably in the UK. This article analyses the impact of the tonnage tax system and its success in achieving its objectives of fleet expansion and employment with particular reference to the UK.     

Biologically induced modification of seawater viscosity in the Eastern English Channel during a Phaeocystis globosa spring bloom

To identify the potential relationship between Pheaocystis globosa bloom conditions and seawater properties, a hydrobiological survey was performed in the inshore waters of the Eastern English Channel over the course of the phytoplankton spring bloom. Chlorophyll concentration, auto- and hetero/mixotrophic composition of protists and standing stock, and seawater viscosity were measured weekly from March to June 2004. The decline of the bloom is characterized by a massive foam formation in the turbulent surf zone. Before foam formation, seawater viscosity significantly increased, showing a significant positive correlation with chlorophyll concentration. In contrast, after foam formation this correlation was negative, seawater viscosity kept increasing despite a sharp decrease in chlorophyll concentrations. No significant correlation has been found between seawater viscosity and the composition of the phytoplankton assemblages observed during the survey. However, significant positive correlations have been found between seawater viscosity and both the size and the abundance of P. globosa colonies. From the correlation patterns observed between chlorophyll concentration and seawater viscosity, we suggest that the rheological properties of seawater are mainly driven by extracellular materials associated with colony formation and maintenance rather than by cell composition and standing stock.     

Systematic variability in repetitious travel

The focus of this paper is the degree to which day-to-day variability in the individual's travel pattern has a systematic, or nonrandom, component. We first review the different sources of variability in travel, emphasizing the difference between between-individual and within-individual variation and the implications of this difference for travel analysis. After discussing the impact of measurement (i.e. the way in which travel behavior is measured) on the study of repetition and variability, we use the Uppsala data to examine the level of systematic variability in an individual's longitudinal travel record. The analysis focuses on two questions:

- How well does observation over one week capture longer-term (five-week) travel behavior; in other words, is behavior highly repetitive from week to week?

- How systematic is within-individual variability; in other words, are certain stops distributed over the five-week record in a nonrandom, that is either regular or clustered, fashion?

Using measures of travel that include more than one stop attribute (e.g. activity, mode, time of day, and location), we found that:

- A seven-day record of travel does not capture most of the separate behaviors exhibited by the individual over a five-week period, but it does capture, for most people, a good sampling of the person's different typical daily travel patterns.

- Whereas a considerable portion of intraindividual variability is systematic (nonrandom), clustering is a more important source of nonrandom variation than is regularity.

The results suggest that behavior does not follow a weekly cycle closely enough for a one-week travel record to measure the longer-term frequency with which the individual makes certain stops or to assess the level of day-to-day variation present in the individual's record. Because these results are likely to reflect the particular measures of behavior we used, one conclusion of this study is the need for other studies that replicate the aims of this one but use a variety of other travel measures. Only through such additional work can we truly assess the sensitivity of our findings to measurement techniques.     

State estimation in roll dynamics for commercial vehicles

Accurate lateral load transfer estimation plays an important role in improving the performance of the active rollover prevention system equipped in commercial vehicles. This estimation depends on the accurate prediction of roll angles for both the sprung and the unsprung subsystems. This paper proposes a novel computational method for roll-angle estimation in commercial vehicles employing sensors which are already used in a vehicle dynamic control system without additional expensive measurement units. The estimation strategy integrates two blocks. The first block contains a sliding-mode observer which is responsible for calculating the lateral tyre forces, while in the second block, the Kalman filter estimates the roll angles of the sprung mass and those of axles in the truck. The validation is conducted through MATLAB/TruckSim co-simulation. Based on the comparison between the estimated results and the simulation results from TruckSim, it can be concluded that the proposed estimation method has a promising tracking performance with low computational cost and high convergence speed. This approach enables a low-cost solution for the rollover prevention in commercial vehicles.     

Transport decision-makers speak: the Seaport Development in the European Communities Research Project†—Part II

This paper, in two parts, reports on the Seaport Development in the European Communities Research Project wherein forty interviews with decision-makers were held in European seaports, and another forty were held with shipowning organizations. This part of the paper reports on analysis of the open-ended tape-recorded responses of the interviewees to six separate sets of propositions they were shown. The first major conclusion is that decision-makers in the ports and shipping industries have a great deal to offer in helping to shape future EC policies about seaports. The second is that these decision-makers on the whole agree with students of the subject, but outside the industries, that a step-by-step approach is possible towards a Common Seaports Policy. Indeed, without prompting, some respondents even confirmed a previously published suggestion for the first stage of this process—the necessity for an agreed standard basis for ports' accounts. It is believed that a small secretariat within the Brussels Commission could weld representatives of the industries into a working group which could make real progress by consulting their colleagues through interviews similar to those successfully conducted for this project.     

The passenger vessel services act and America's cruise tourism industry

The Passenger Vessel Services Act (PVSA) of 1886, a cabotage law, attempts to shield U.S. maritime shipping from foreign competition. It also applies to the U.S. cruise ship industry. The PVSA requires foreign cruise ships that carry passengers between U.S. ports to also stop at foreign ports. Norwegian Cruise Line America (NCLA), which operates one U.S. flagged cruise ship in Hawaii, wants the U.S. Customs and Border Protection to require foreign cruise ships offering Hawaii itineraries from the U.S. west coast to spend more time in foreign ports. We analyze the merits of NCLA's proposal. We argue that rather than making the PVSA even more protectionist, the law should be repealed.     

The Impact of Recreation on Barrier Islands: A Case Study on Masonboro Island

Since 1992, coastal researchers at the University of North Carolina at Wilmington have been documenting the impacts of human recreational use on Masonboro Island, a component of the North Carolina National Estuarine Research Reserve, and the subsequent natural processes that mitigate these impacts. Both short-term and long-term natural mitigational processes were identified. The effects of these processes were found to be much more rapid than similar impacts on typical terrestrial settings. However, careful examination of the data suggests that both physical location of the impact site and natural variability of weather patterns and events play a role. Management implications of these findings are proposed.