Ranking of factors contributing to higher performance in the ocean transportation industry: a multi-attribute utility theory approach

Ocean transportation has been mainly studied from an economic and strategic point of view. This paper adopts an operations management approach aiming at the identification of the value-adding attributes that characterize the ocean transportation industry. This is achieved by using Johansson et al.'s 1 four value metrics—service, quality, cost, time—which are used for the identification of the contribution that different factors make to the total created value. In this paper, multi-attribute utility theory (MAUT) has been used to measure and compare the value of different processes of various sectors of the ocean transportation industry. The application of MAUT methodology is illustrated with an example from the four sectors of the industry: liner, dry bulk, liquid bulk and specialized. Results suggest that there is strong emphasis placed by ocean transportation companies on quality and that there is differentiating importance put on service and cost by different sectors. Time is seen as the lowest value contributor by all four sectors of the surveyed companies.     

A new era for airport regulators through capacity investments

Private and public airports’ optimal actions may not coincide. While private airports usually pursue profit maximization, publicly owned airports look for maximum social welfare. Thus, the prices charged by private airports may differ from the socially optimal charges and public intervention may be needed. In this paper, we analyze airport charges when an increase in frequency produces positive or negative externalities and carriers have market power. We use the methodology of game theory to show that there may exist a level of capacity for which private and social objectives coincide, so no price regulation is needed. Thus, the usual role of regulators and planners could be modified in order to decide the appropriate capacity investments for which airport regulation is no longer necessary.     

Hydroelastic responses and interactions of floating fuel storage modules placed side-by-side with floating breakwaters

This paper is concerned with the hydroelastic responses and hydrodynamic interactions of two large floating fuel storage modules placed side-by-side with the presence of floating breakwaters. These modules and breakwaters form the floating fuel storage facility (FFSF). The floating storage modules and breakwaters are modeled as plates and the linear wave theory is used to model the water waves in the numerical model. The numerical model is verified with existing numerical results and validated with experimental test. Numerical simulations are performed to determine the hydroelastic behavior and hydrodynamic interactions of floating storage modules placed adjacent to each other and enclosed by floating breakwaters under various incident wave angles. The effects of breakwaters, drafts, channel spacing formed by the two adjacent modules and water depth on the hydroelastic responses of the modules are investigated. The wave induced responses of multiple floating storage modules enclosed by floating breakwaters are also examined.     

Assessment of hub status among Asian ports from a network perspective

This paper proposes a novel network-based hub port assessment (NHPA) model through explicit formulations of connectivity and cooperation indices. Such a model is useful for port operators and policy makers to evaluate the relative influences of various quality characteristics from which carriers base their port choices on and identify port partners. Key insights can be obtained for port authorities to improve their port infrastructures and operations to achieve a competitive and sustainable hub port status. Three comprehensive case studies are conducted to assess the current standings and potentials of major Asian ports within networks of major carriers.     

Concept for a risk based Navigation Decision Assistant

A concept for a risk based decision support system for navigation of ships that face degrading weather conditions and dangers of damages to a ship at its cargo is outlined. Similar systems exist in various forms, mostly as prototypes, and are based on different ideas of how decision parameters should be communicated to a master as improved basis for decision making. The paper advocates that it is possible to develop a system that systematically is built on risk assessment approaches with the intention of being applicable for a specific ship with a specific loading situation in a real-time environment. The concept is based on modern reliability methodology and relies on state-of-the-art hydrodynamics software and information sources relating to the environment. Based on the various consequences that may occur, the study suggests a selection of limit states and shows how they can be integrated in the decision support system described. The paper presents the risk based concept only while testing of the concept is still in progress.     

Fatigue analysis of butt welded AH36 steel joints: Thermographic Method and design S–N curve

The traditional methods of fatigue assessment of welded joints have some limitations, and are extremely time consuming. In order to overcome these difficulties, the Thermographic Method (TM), based on thermographic analyses, has been applied to predict the fatigue behaviour of butt welded joints, made of AH36 steel, largely used in shipbuilding. Experimental tests have been carried out to assess the fatigue capability in terms of S–N curves and fatigue limits. The predictions of the fatigue capability obtained resorting to the Thermographic Method show a good agreement with those derived from the traditional procedure. Moreover, the fatigue design recommendations were compared to the experimental data in order to analyse the reliability of the codes.     

Habitat characteristics as determinant of the structure and spatial distribution of epibenthic and demersal communities of Le Danois Bank (Cantabrian Sea, N. Spain)

The purpose of this paper is to detect and describe general trends in the spatial distribution of epibenthic and demersal communities of Le Danois Bank (El Cachucho) in relation to the environmental variables that characterize their habitat by means of multivariate ordination. Data were derived from two multidisciplinary surveys carried out in October 2003 and April 2004 included in the ECOMARG project. The surveys were focused on the study of the physical scenario, including both geological (seabed characterization from bathymetry and backscatter data) and hydrographic features, and the different compartments of the benthic fauna (endobenthic, epibenthic, suprabenthic and demersal communities). For the present study, epibenthos and demersal species were sampled using two different gears, a 3.5 m beam trawl and a Porcupine 39/52 type baca otter trawl respectively. The total species richness combining both samplers ascended to 221, including 71 species of fishes, 65 crustaceans, 35 molluscs, 29 echinoderms, 10 cnidarians and 5 sponges.Multivariate methods were used for the study of the characteristics of communities and habitats. Hierarchical cluster analysis was applied to calculate and visualize similarities between samples in terms of species composition. To assess the amount of variation of faunal densities related to a set of eight environmental variables, a redundancy analysis (RDA) was used. The set of environmental variables used were: depth, near-bottom temperature and salinity, sedimentary typology (dry weight percentages of coarse sands, medium and fine sands, silt and organic matter) and seafloor reflectivity. Using the spatial distribution of the ranges of depth and seafloor reflectivity that characterize the habitats of the faunal assemblages we defined the spatial distribution of the different communities.The multivariate analysis of 18 beam-trawl samples and 15 otter trawl samples showed the existence of 4 main assemblages associated with the more characteristic habitats of the area. The Callogorgia–Chimaera community live mainly in the areas at the top of the Bank (425–550 m depth), where the sediment coverage is lower and there exists a high presence of rocky outcrops. The Gryphus–Galeus community were found in the areas at the top of the Bank covered by medium and fine sand sediments with low organic matter content. The Phormosoma–Trachyrincus community live on the sedimentary terraces that characterize the Bank break (550–800 m) and the Pheronema–Deania community occupy all the deeper (800–1050 m) sedimentary grounds of the inner basin.     

Différences de sexe et rôle de l’internalisation des règles sur la propension des enfants à prendre des risques à vélo

The objective of this study is to explore gender differences and effect of internalization of traffic rules on children’s propensity to take risks as cyclists. Risk perception, internalization of traffic rules, and self-reported risk-taking propensity as cyclist were measured in a questionnaire among 145 children (86 boys and 59 girls) aged 9 to 12. The results show gender differences in cycling rules internalization, risk perception, and risk-taking propensity as cyclist. Furthermore, the results show that internalizing traffic rules is a better predictor than biological sex of the propensity to take risks as cyclist.     

Multi‐criteria analysis for evaluating the impacts of intelligent speed adaptation

Road safety is a policy priority due to the high casualties and costs associated with road accidents. Since speed is a major cause of road accidents, in‐vehicle speed limiters or Intelligent Speed Adaptation (ISA), seems a promising solution. ISA implementation, however, is hindered by large uncertainties, for example about the impacts of ISA, the way users might respond to ISA, and the relationship between speed and accidents. Traditional Multi‐Criteria Analysis (MCA) has limitations in handling these uncertainties. We present an MCA approach based on exploratory modeling, which uses computational experiments to explore the multiple outcomes of ISA policies (safety, emissions, throughput, and cost) across a range of future demand scenarios, functional relationships for performance criteria, and user responses to ISA. As an illustration, by testing the impacts of different ISA penetration levels on two driver groups, we show that when compliance with ISA is expected to be low, a policy aimed only at novice drivers outperforms other ISA policies on safety improvement.     

Store-and-forward based methods for the signal control problem in large-scale congested urban road networks

The problem of designing network-wide traffic signal control strategies for large-scale congested urban road networks is considered. One known and two novel methodologies, all based on the store-and-forward modeling paradigm, are presented and compared. The known methodology is a linear multivariable feedback regulator derived through the formulation of a linear-quadratic optimal control problem. An alternative, novel methodology consists of an open-loop constrained quadratic optimal control problem, whose numerical solution is achieved via quadratic programming. Yet a different formulation leads to an open-loop constrained nonlinear optimal control problem, whose numerical solution is achieved by use of a feasible-direction algorithm. A preliminary simulation-based investigation of the signal control problem for a large-scale urban road network using these methodologies demonstrates the comparative efficiency and real-time feasibility of the developed signal control methods.