Development of vessel traffic services: Legal considerations

Legislative measures, rather than further technological advances, are needed if there is to be any extensive development of Vessel Traffic Services. Reasons are given why this conclusion differs from that of the COST 301 Study with respect to legal liability of Vessel Traffic Services.     

Systematic training for maritime transport managers

Providing effective training for managers in the maritime and ports sector in developing countries has proven to be a daunting task. Initial attempts by the United Nations Conference on Trade and Development (UNCTAD) in the 1970s led to the development of senior port manager residence courses in Sweden. However, Given the vast numbers of managers needing training a more eficient method was required. Using the systematic training techniques pioneered by the International Telecommunications Union, UNCTAD, in the 1980s initiated two parallel programme: Trainmer (Training development in Maritime Transport); and IPP (Improving Port Performance). Both of these programmes demonstrated considerable success in terms of the numbers of maritime and port managers receiving training opportunities. Increased cooperation amoungst international agencies providing training programmes should result in improved transport management training in the 1990s, lrading to increased efficiences in port and related transport systems.     

Forecasting tanker freight rate using neural networks

Improvement in forecasting accuracy is a difficult task but critical for business success. This paper investigates the potential of neural networks for short- to long-term prediction of monthly tanker freight rates. Procedures are outlined for the development of the neural networks. The problem of under-training and over-training is addressed by controlling the number of iterations during the training process of neural networks. A comparative study of predictive performance between neural networks and ARMA time series models is conducted. Our evience shows that neural networks can significantly outperform time series models, especially for longer-term forecasting.     

Highly disaggregrated models of seaborne trade. An empirical model for bilateral dry-cargo trade flows in the World economy

The aim of this paper is to estimate an empirical model of bilateral dry-cargo seaborne import flows in the international economy. Seaborne trade elasticities are estimated for the first time, utilizing the Constant Ratio of Elasticities of Substitution Homogeneous/Homothetic (CRESH) function, a function very rarely used in the past. Highly disaggregated data on volumes of seaborne trade, published by the UN, distinguish between five types of cargo according to the type of ship used for its transportation, and 30 trading regions according to the major sea-lancs used by ships internationally. Multistage budgeting is employed to make the problem of estimation tractable. An empirical model for dry-bulk cargo is estimated based on the CRESH function. Estimation of bilateral export price elasticities enables comparison of the degree of competition in each import market over export regions, and amongst import markets themselves. Risk-averse ship owners may utilize such a comparison to operate in world shiplanes with low degree of competition.     

The egg morphology of 7 Acartiidae species: a preliminary survey of the ootaxonomy of calanoids

This is the first contribution to acartiid taxonomy based on egg morphology. Eggs laid under laboratory conditions by maintaining female specimens of Acartia adriatica, A. clausi, A. italica, A. margalefi, A. tonsa, Paracartia latisetosa and Pteriacartia josephinae were studied by S.E.M. Most species produced eggs with intraspecific variation in their external morphology. In spite of such variation, however, it was possible to separate three species groups.     

Passive Repulsive MagLev: Concept and Experimental Demonstration

A simple demonstrator for a magnetic levitation vehicle (MagLev) based on repulsive suspension forces generated by permanent magnets is presented. The lateral and yaw motions are stabilized using controlled electromagnets. A mathematical model, aimed mainly at defining the control strategy, has been developed and then experimentally validated using the demonstrator. Two different control strategies have been tested, namely a zero position error and a zero average current control strategy. Both proved to grant a stable behaviour and to effectively counteract external force disturbances. This demonstrator will be used in future research on MagLev vehicles but also on magnetic suspensions in general.     

Carrier selection in a RO/RO ferry trade Part 2. Conceptual framework for the decision process

The way that users select a shipping service from the range of available options is a complex and poorly understood process. It is difficult, if not impossible, to reduce all the attributes to a single dimesion—such as cost—and in reality no-one tries to do so. Using the results of a survey of shippers, a behavioural framework has been constructed to represent the stages in the decision process and the interaction of factors that influence the shipping manager. Previous models have tended to isolate and examine individual components of the process and have not linked these components together to form an integrated explanation. The proposed framework is a multi-stage process with elements of both compensatory and non-compensatory behaviour and a strong emphasis on risk avoidance.