The marine electronic highway in the Straits of Malacca and Singapore—an assessment of costs and key benefits

The Straits of Malacca and Singapore are an important trade route linking the Indian Ocean to the South China Sea and Pacific Ocean. They are also rich in resources and support a range of activities that benefit the economies of the littoral states (Indonesia, Malaysia and Singapore). This important shipping route is a very congested waterway and the authorities are keen to improve navigation facilities to promote ship safety and reduce the risk of groundings, collisions and accidents. This will also help to protect the marine environment from the effects of pollution and hence reduce its damaging impact on activities related to the Straits, e.g. fisheries and tourism. The Marine Electronic Highway (MEH) is an attempt to bring together maritime safety technologies and environmental management systems. The paper examines the costs of providing such a highway and considers some of the benefits which could accrue from its implementation. The analysis, conducted in the form of a cost-benefit study, clearly shows the economic viability of the scheme.     

Some errors in macroscopic traffic models based on car following models

The macroscopic traffic flow models developed from the car following models of Gazis et al. (1961) are shown to have a flaw in that they do not meet certain of the boundary conditions that researchers have said that they do. This does not affect many existing models but, nevertheless, should be cleared up.     

The influence of food quality on the nutritional acclimation of the copepod Acartia clausi

The influence of food quality on the nutritional metabolism of Acartia clausi was studied experimentally using four different diets: (1) diatom cells of Thalassiosira weissflogii, (2) detritus prepared from the same culture, (3) 50 : 50 mix on a protein basis of the two previous diets, and 4) dinoflagellate cells of Prorocentrum micans. For each trophic, ingestion, gut transit time, trypsin activity and K_m (half saturation constant) were measured at limiting and saturating concentration. Assimilation rates were also estimated for both pure diatoms and mixed live–detrital cell diets. Ingestion followed a Holling type 2 response for diets 1 and 4, a linear one for detritus and an intermediate response for diet 3. Gut transit time displayed different adaptive changes with food regime depending on protein concentration. Trypsin activity was lower for detrital food and trypsin K_m significantly decreased with increasing concentration of live diatoms. Assimilation rates were higher for live food than for mixed live–detrital food. Results illustrated that Acartia-type copepods optimize nitrogen or protein uptake. They suggest that besides chemoreception-mediated selectivity, internal controls by digestion and assimilation also regulate ingestion (feed-back).     

Application of Inverse Models to Vehicle Optimization Problems

This paper presents a nonlinear inverse model of a road vehicle which simulates combined steering and braking/driving. The inputs to the model are the lateral and longitudinal acceleration of the vehicle's sprung mass center. The simulation returns the steering wheel angle and brake/drive torques required to obtain the desired accelerations. An example is presented which demonstrates the utility of inverse models for optimization purposes.     

Experimental study on piston- and sloshing- mode moonpool resonances

An experimental study was performed on the piston- and sloshing-mode moonpool resonances of offshore structures. Two different geometries were considered to investigate the flow characteristics in a plain moonpool and a moonpool with a cofferdam. To examine the efficiency of a cofferdam for reducing the flow in a moonpool, three cofferdam geometries were tested. The plain moonpool presented violent flows as a result of the piston- and sloshing-mode resonances. However, the moonpool with the cofferdam introduced violent sloshing waves instead of the ascent and descent of the water column in the piston-mode moonpool resonance. Among three different cofferdam geometries, the model with a right triangle facing to the left on the top of the cofferdam was most effective in reducing the flow in the moonpool when compared with the other models.     

法国Z 21500 区间电动车组

介绍了法国Z 21500区间电动车组的结构、主要技术参数和设备.     

Scientists and Crew

This study reports on scientist/crew relations aboard research vessels at sea. It is a case study in a case study in a long-range project dealing with the relations of natural scientists in the U.S.A. to various segments of the lay population. An earlier paper dealt with the interaction of scientists and Government policy makers during the science-advisory process [1]. In that study we found that the frustration was reciprocal; scientists and policy makers were equally vocal on what was wrong with ‘ the other groups’. The present research, by comparison, focuses on scientists and members of ‘the working class’. Here we find the frustration rather one-sided, reflecting the differences in status and power of the two groups. On a research vessel, science and scientists control the lives and careers of the mariners. In the science-advising committee, members of both government and science meet as social equals.

In this paper elements of conflict between scientists and crew on a research vessel are described. It is suggested that conflict between these two groups is the inevitable result of extending the ‘intellectual’/‘worker’ class conflict of our society to a closed space at sea. The controlling mechanism of the conflict may be called ‘subcultural privacy’, a mechanism worked out by mariners to cope with the disrupting effects of a constant stream of strangers into their sea-going home. The mechanism takes the form of institutionalized ‘bitching’ and systematic physical separation of scientists and crew during critical periods of the day. It is suggested that attempts to create greater crew/scientist harmony by forcing by greater interaction (and thus a breakdown of subcultural privacy) will be counter productive.     

Traveled distance,stock and fuel efficiency of private vehicles in Canada: price elasticities and rebound effect

This paper presents estimates of the rebound effect and other elasticities for the Canadian light-duty vehicle fleet using panel data at the provincial level from 1990 to 2004. We estimate a simultaneous three-equation model of aggregate demand for vehicle kilometers traveled, vehicle stock and fuel efficiency. Price and income elasticities obtained are broadly consistent with those reported in the literature. Among other results, an increase in the fuel price of 10% would reduce driving by ~2% in the long term and by 1% the average fuel consumption rate. Estimates of the short- and long-term rebound effects are ~8 and 20%, respectively. We also find that an increase in the gross domestic product per capita of 10% would cause an increase in driving distance of 2–3% and an increase of up to 4% in vehicle stock per adult. In terms of policy implications, our results suggest that: (1) the effectiveness of new fuel efficiency standards will be somewhat mitigated by the rebound effect and (2) fuel price increases have limited impacts on gasoline demand.

Maintaining the maritime skills base: does the Government have a realistic strategy?

The UK has a requirement for people with seafaring expertise to fill a wide range of jobs in the maritime-related sector of the economy ashore. The pool of seagoing ships' officers has now reached the level where shore-based demand for such officers cannot be satisfied by natural wastage from this pool alone. This paper considers the implications of this for the Government's recently announced strategy for maintaining the maritime skills base. The paper concludes that it is inevitable that the Government's present strategy will fail, and suggests what measures need to be taken if the skills base is to be saved.