Percorrer por autor "Guedes Soares, C."
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- AIS Based Shipping Routes Using the Dijkstra AlgorithmPublication . Silveira, P.; Teixeira, A.P.; Guedes Soares, C.This paper proposes an approach for identifying and characterizing shipping routes using information contained in Automatic Identification System messages broadcasted by ships and recorded by the coastal Vessel Traffic Service centre. The approach consists of using historical Automatic Identification System data to build a graph, where nodes are cells of a grid covering the geographical area being studied and the weights of directional edges are inversely related to ship movements between cells. Based on this graph, the Dijkstra algorithm is used to identify a potential safe route, assumed to be the most used route by ships between two locations. A second graph is created simultaneously, with the same nodes and edges, but with edge weights equal to the average speed of transitions between cells, thus allowing the determination of the average speed profile for any possible path within the graph. The proposed approach is applied to two scenarios: an approach to the port of Lisbon and the entry through the fairway to a RO-RO terminal in the port of Setubal in Portugal.
- Multipliers, linkages and influence fields among the sectors of the Portuguese maritime clusterPublication . Simões, A.; Salvador, R.; Guedes Soares, C.The main objective of this paper is to present the multiplier effects on the Portuguese economy of the main maritime sectors and their comparison with other economic sectors, in particular the key activities of which they are suppliers or buyers. One way of evaluating economic activities, which is adopted in this paper, is through the sectorial linkage indices and their interdependence, displaying their direct, indirect and induced effects, which can be quantified with the use of the Leontief (input-output) matrix. Based on the input-output matrix, one obtains the interconnection coefficients, the multiplying factors and the influence fields. Based on the values of the interdependence coefficients, the economic activities are analyzed and classified by its importance to the national economy. The paper identifies a broadly diversified productive structure, with several key sectors, which, if stimulated, can significantly boost the growth of other sectors and the overall economy.