Bus arrival time prediction at bus stop with multiple routes

Provision of accurate bus arrival information is vital to passengers for reducing their anxieties and waiting times at bus stop. This paper proposes models to predict bus arrival times at the same bus stop but with different routes. In the proposed models, bus running times of multiple routes are used for predicting the bus arrival time of each of these bus routes. Several methods, which include support vector machine (SVM), artificial neural network (ANN), k nearest neighbours algorithm (k-NN) and linear regression (LR), are adopted for the bus arrival time prediction. Observation surveys are conducted to collect bus running and arrival time data for validation of the proposed models. The results show that the proposed models are more accurate than the models based on the bus running times of single route. Moreover, it is found that the SVM model performs the best among the four proposed models for predicting the bus arrival times at bus stop with multiple routes.     

Autonomous vehicle control systems for safe crossroads

This article presents a cooperative manoeuvre among three dual mode cars – vehicles equipped with sensors and actuators, and that can be driven either manually or autonomously. One vehicle is driven autonomously and the other two are driven manually. The main objective is to test two decision algorithms for priority conflict resolution at intersections so that a vehicle autonomously driven can take their own decision about crossing an intersection mingling with manually driven cars without the need for infrastructure modifications. To do this, the system needs the position, speeds, and turning intentions of the rest of the cars involved in the manoeuvre. This information is acquired via communications, but other methods are also viable, such as artificial vision. The idea of the experiments was to adjust the speed of the manually driven vehicles to force a situation where all three vehicles arrive at an intersection at the same time.     

Mesozooplankton species distribution in the NW and N Iberian shelf during spring 2004: Relationship with frontal structures

We have analysed the mesozooplankton community structure in the southern Bay of Biscay shelf and its relationship with the hydrographic conditions during spring 2004. According to thermohaline characteristics, we observed two frontal zones of distinct origin along the shelf (around 7° and 3°W), that allowed us to differentiate three different hydrographic domains. The westernmost part of the shelf (WC), defined by the presence of relatively warm and salty water related to the presence of the Iberian Poleward Current (IPC), the easternmost region (EC), characterized by colder and fresher water and subject to the influence of freshwater inputs from the Adour river in the French coast, and a region in the Central Cantabrian Sea (CC), where thermohaline characteristics were intermediate between these two extremes. The mixing layer depth (MLD) regime in these areas was also different: the WC region was characterized by a mixed water column, whereas in the EC region the river discharges produces stratification of the upper meters of the water column (< 10 m); in the CC region, we found a distinct vertical mixing regime that separated coastal (stratification) from shelf (mixed water column) stations, giving rise to a notorious across-shelf front. We found a good match between the aforesaid hydrographic regions and the distribution of mesozooplankton species composition and community assemblages: the Mantel correlation between physical variables and mesozooplankton distribution was highly significant (n = 63, r = 0.70, α < 0.001). In the WC region, the community was dominated by Paracalanus parvus, Oithona helgolandica, Acartia clausi and Clausocalanus pergens, while in the EC region the most dominant species were Noctiluca scintillans, Oncaea media and Temora longicornis. The CC region showed similar composition of copepods than the WC region, but larvaceans (Oikopleura spp. and Fritillaria spp.) were more abundant in the CC region than in the WC region. Within each zone, the relative abundances of the dominant species differed between coastal and shelf locations.     

Competing Visions for Marine Tenure and Co-Management: Genesis of a Marine Management Area System in Chile

Chile has been attempting to establish a Management Area (MA) system that melds the use of marine protected areas with marine tenure. The process has brought to the fore the competing interests of various user groups: artisanal fishermen, marine science professionals, government managers, tourist developers, and the Navy. We explore the core relationships among fishermen and the ecologists and biologists whose work is essential for establishing and maintaining a MA. The MA system's creation and implementation raise the key question of whether a marine tenure system can work under the conditions imposed by the Chilean government. There is a need to recognize and reconcile contradictions in a government management model that strives simultaneously to be a conservation zone and a financially profitable co-management zone. This article examines the MA management system's fault lines in the context of Chile's political economy, and the intimate interaction of management with fishermen's cultural survival strategies.     

Path-planning algorithm for ships in close-range encounters

Efficient maritime navigation through obstructions at close range is still one of the many problems faced by mariners. The increasing traffic densities and average cruise speed of ships also impede the collision avoidance process by reducing the time available for decision making. This study develops a path-planning algorithm that determines an optimal navigation path for ships in close-range encounters, using known and predicted data about the traffic and environment. An improved ship dynamic model has also been developed to better approximate the ship movement under external influences, and the algorithm was evaluated with a set of test cases simulating various traffic scenarios typically encountered at close range. Since the method is based on evolutionary algorithm, the algorithm behaviours were evaluated statistically, where properties such as consistency and practicality of the algorithm outputs are discussed.     

Can agents measure up? A comparative study of an agent-based and on-line optimization approach for a drayage problem with uncertainty

Experiments studying the behavior of agent-based methods over varying levels of uncertainty in comparison to traditional optimization methods are generally absent from the literature. In this paper we apply two structurally distinct solution approaches, an on-line optimization and an agent-based approach, to a drayage problem with time windows under two types of uncertainty. Both solution approaches are able to respond to dynamic events. The on-line optimization approach utilizes a mixed integer program to obtain a feasible route at 30-s intervals. The second solution approach deploys agents that engage in auctions to satisfy their own objectives based on the information they perceive and maintain locally. Our results reveal that the agent-based system can outperform the on-line optimization when service time duration is highly uncertain. The on-line optimization approach, on the other hand, performs competitively with the agent-based system under conditions of job-arrival uncertainty. When both moderate service time and job-arrival uncertainties are combined, the agent system outperforms the on-line optimization; however, in the case of extremely high combined uncertainty, the on-line optimization outperforms the agent-based approach.     

Do maritime passengers’ subsidies in Europe affect prices?

Some European governments subsidize their residents when they travel at sea. This paper seeks to analyze the impact on prices of maritime passengers’ subsidies in Europe. Following a review of the scarce academic literature on this topic and the subsidy scheme in Europe, a sample of firms’ prices and other characteristics of 40 European routes for 2016 are analyzed. Both an estimation of a price equation and a matching approach are applied and reach the same conclusion: prices per kilometer are around 40 per cent higher on those subsidized routes due to subsidies. This outcome reduces the potential subsidy gain to consumers.     

Propeller torque load and propeller shaft torque response correlation during ice-propeller interaction

Ships use propulsion machinery systems to create directional thrust. Sailing in ice-covered waters involves the breaking of ice pieces and their submergence as the ship hull advances. Sometimes, submerged ice pieces interact with the propeller and cause irregular fluctuations of the torque load. As a result, the propeller and engine dynamics become imbalanced, and energy propagates through the propulsion machinery system until equilibrium is reached. In such imbalanced situations, the measured propeller shaft torque response is not equal to the propeller torque. Therefore, in this work, the overall system response is simulated under the ice-related torque load using the Bond graph model. The energy difference between the propeller and propeller shaft is estimated and related to their corresponding mechanical energy. Additionally, the mechanical energy is distributed among modes. Based on the distribution, kinetic and potential energy are important for the correlation between propeller torque and propeller shaft response.     

Port choice in container market: a literature review

As a result of the intense changes occurring in port environment over the last decades, new models of competitiveness have been developed, where port authorities try to increase their attractiveness. In this context, one of the most debated issues in this area of research is still the role played by port authorities in defining port competitiveness. The aim of this paper is to provide a review of port choice literature enabling to identify the main port choice’s criteria in order to define the role played by Port Authorities and to point out future lines of research that should be undertaken to fully incorporate current ports’ environment and performance. The results show that although some studies point out the importance of geographical factors in port choice, a larger number of studies defend the increasing role played by port authorities in determining the competitiveness through investing in port infrastructure, improving port efficiency or hinterland accessibility. Despite the existing models contributing on this topic, there are still some gaps in terms of measuring the port performance, including port strategies and studying the port choice for specific industries.