Some aspects of cruise ships

Historically there have been only two groups involved in the conflict that has engulfed the US maritime industry for the past fifty years maritime labour unions and shipping companies. The configuration of these groups at different times in this struggle, has led to distinct periods of conflict in the industry. This paper analyses the basis and continuation of the problem.     

Book reviews

R. S. Farrow, with J. M. Broadus, T. A. Grigalunas, P. Hoagland III, and J. J. Opaluch. 1990. Managing the Outer Continental Shelf Lands: Oceans of Controversy. New York: Taylor & Francis New York, 168 pp., paper.

Richard A. Kenchington. 1990. Managing Marine Environments. New York: Taylor & Francis, 248 pp.     

The Asian economic crisis and the aviation industry: Impacts and response strategies

Most airlines across Asia are struggling to cope with an unprecedented economic crisis which they have very little control over, and the survival of some remains in doubt. The continuing uncertainty generated by the crisis has accelerated the process of change in the aviation industry and has highlighted the need for adaptability, and its effects have been deeper and longer lasting than previously anticipated. After a year-long slump in the Asian travel market, airlines are now considering a range of options and rehabilitation programmes including a series of cost-cutting measures. There appears to be a trend towards the extension and consolidation of strategic alliances, structural and operational reorganization, and the application of new technologies. The success of these measures will become apparent over time, but action is necessary to minimize the adverse consequences of the crisis which has dominated the region since 1997.     

Surface intersection in geometric modeling of ship hulls

In this work a methodology is presented for the computation of the intersection of parametric surfaces, namely Non Uniform Rational B-Splines (NURBS), with special attention to some specific requirements for applications to ship hull modeling. The algorithm adopted and the steps of the proposed method are described, namely checking whether the surfaces intersect, preprocessing of linear surfaces with strong discontinuities, computation of starting points, marching along intersection curves, and approximation of the intersections with NURBS curves. Finally, the results of some intersection tests are presented and discussed. The results are validated by comparison with results of commercial codes.     

Who switches to hybrids? A study of a fuel conversion program in Colombia

Air pollution from mobile sources is an important environmental problem in larger cities. In 2001, a program was implemented to encourage the use of natural gas in vehicles in the Aburrá Valley in Colombia, with incentives to convert small cars from gasoline and diesel to hybrid engines with natural gas, most notably a cash subsidy. Using a survey administered to both commercial and private car owners we study the determinants of conversion under this fuel conversion program. We thus obtain information about the reasons for adoption of new technologies in vehicles. This allows us to discuss the possible outcomes of this type of policy. Results show that a large part of owners who switched would have done it anyway without the subsidy. Based on the findings, commercial vehicles are most likely to be converted to natural gas vehicles.     

Assessing the long term benefit of banning the use of hand-held wireless devices while driving

An increasing number of legislative efforts have been undertaken to prohibit the use of hand-held wireless devices while driving. As of July 2012, ten states and the District of Columbia enforce laws banning the use of hand-held cell phones while driving. Thirty-nine states and the District of Columbia have banned text messaging while driving. Recent studies of driver behavior suggest that hand-held wireless device usage negatively impacts driver performance. However few studies at the aggregate level address the plausible link between the use of hand-held wireless devices while driving, increased risk of automobile accidents, and government legislative efforts to reduce such risk. This paper analyzes data at the aggregate level and builds a regression model to estimate the long term accident rate reduction due to a hand-held ban. This model differs from previous studies, which consider short term accident rate reduction, by considering time trends in the accident rate due to the ban. Additionally, counties considered in this analysis are placed into groups based on driver density, defined by the number of licensed drivers per centerline mile of roadway, and a separate analysis is performed within these groups. This approach allows one to better quantify the effect of hand-held bans in counties of different driver densities. Results from this paper suggest that bans on hand-held wireless device use while driving reduce the rate of personal injury accidents in counties with high levels of driver density, but may increase accident rates in counties with low driver density levels. These results can inform transportation policymakers interested in reducing automobile-accident-risk attributable to the use of hand-held wireless devices while driving.     

Approach to assess a fast welding simulation in an industrial environment — Application for an automotive welded part

Fusion welding processes are widely used for joining metal structures, such as pipes, ships, and cars. In general, these joining processes offer a very good compromise between reliability, safety, cost and maintenance which are important issues in the current economical context. The negative heat effects of welding, i.e. distortions and residual stresses of the welded parts, are well known and many researches in this field have already been done in the last decades in order to minimize them. On the experimental side, many sophisticated procedures have become state of the art to deal with this problem. On the computational side, the improvement of the simulation algorithms and the computing power enables the simulations of many physical phenomena occurring during the welding process. The implementation of welding simulation techniques is nevertheless not an easy task and often associated with expert knowledge which hinders their global application in an industrial environment. This paper is focused on the industrial requirements of a welding simulation software with special respect to the needs of the automotive industry. The necessary information to run a welding simulation and the expectations of a weld specialist without deep knowledge in numerical methods are investigated. These expectations are tested on an automotive welded assembly with a commercially available welding simulation software designed especially for the needs of the automotive industry. A welding experiment is done and the measured temperature distributions and distortions serve as reference to validate the simulation results. The result quality of the simulations of temperature fields and distortions is in best agreement with experimental data. The workflow is well adapted for the considered industrial requirements and the time-tosolution as well as the computational costs are acceptable, whereas the efficient calibration of the heat input model is still a point which will be further investigated in current and future research works.     

Federal consistency and state expectations

Abstract

The requirement in the Coastal Zone Management Act of 1972 that federal projects be consistent with approved state coastal zone management programs is an important incentive for states to complete their programs. As a condition of program approval, states must first consult with the federal agencies concerned and provide opportunities for comment, with the hope of avoiding conflicts. The consistency requirement is also subject to various exceptions whose scope remains to be determined. One such exception of uncertain extent is the exclusion from the coastal zone of federal lands “the use of which is subject solely to the sole discretion ... of the Federal Government....”; Despite these uncertainties, however, the consistency provision represents a major change in federal policy, which has traditionally allowed federal agencies to operate largely without concern for state land or water use requirements.     

Institutional structure of New Zealand licensed road freight carriers

Road freight transport in New Zealand has operated under government regulations since 1936, primarily to protect the freight revenue of the New Zealand Railways. In 1983 an Act was passed to deregulate the freight transport industry and to switch over to a qualitative licensing system. This is expected to have some impact on competition within the road freight industry as well as between road and rail. This paper analyses the institutional structure of the road freight industry at the pre‐deregulation phase. The trend over the last few years, shows that the number of single vehicle owners (mostly owner‐drivers) and their share in the industry is growing at a faster rate than others. The vehicle authority distribution varies widely from one region to another in the country. Economic factors like employment, population, urbanization etc. could not explain this variation. The segregation of demand by existing government regulations appears to be the main reason for such diversity in vehicle authority distribution. Apparently there is no monopoly trend in the aggregate nor in the regional distribution. However, many owner drivers work closely with large firms, which may change the concentration observed in the distribution of vehicle authorities.

Productivity is relatively high for one person operations, i.e., mainly owner drivers. It then goes down and then rises to a certain limit. This gives an indication of the possibility of economies of scale, the single vehicle firms being an exception.