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Autonomous robot path construction prototype using wireless sensor networks
Amaro, José Paulo; Caldeira, J.M.L.P.; Soares, V.N.G.J.; Dias, João A.The use of wireless sensor networks (WSN) can be a valuable contribution in disaster situations or life-threatening exploration. Using wireless mobile robots, it is possible to explore vast areas without human intervention. However, the wireless network coverage that can keep mobile robots connected to the base station / gateway is a major limitation. With this in mind it was created a prototype of an extensibl...
Network management and monitoring solutions for vehicular networks: a survey
Dias, João A.; Rodrigues, Joel; Soares, V.N.G.J.; Caldeira, J.M.L.P.; Korotaev, Valery; Proença, MárioVehicular networks are emerging as a promising technology that enables reliable and low-cost solutions for intelligent transport systems (ITSs), mainly due to their enormous potential to be considered for multiple purposes and scenarios. These networks are characterized by unique and challenging features such as packet fragmentation, low node density, short contact duration, and network disruption. These featur...
The ITRAX core scanner, a useful tool to distinguish anthropic vs. climatic inf...
Martins, Virgínia A.; Dias, João A.; Bernardes, Cristina; Rubio, Belén; Bernabeu, Ana; Rey, Daniel; Soares, António M.; Sobrinho, FredericoThe main goal of this work is to distinguish anthropic and climatic influences in sediments from the lagoon of Aveiro (Portugal). This study is based on a core (240-cm long) collected in Murtosa Channel. Optical and X-radiographic images and high-resolution elemental profiles were acquired with ITRAX micro-X-ray fluorescence (XRF) core scanner. Samples collected at each ≈3 cm along the core were analysed for gr...
Assessment of the health quality of Ria de Aveiro (Portugal): heavy metals and ...
Martins, Virgínia A.; Frontalini, Fabrizio; Tramonte, Keila M.; Figueira, Rubens C. L.; Miranda, Paulo; Sequeira, Cristina; Fernández-Fernández, SandraThis work analyses the distribution of heavy metals in the sediments of Ria de Aveiro (Portugal) assessed by total digestion and sequential chemical extraction of the sediments. The influence of environmental parameters on the living benthic foraminiferal assemblages was studied. The most polluted parts in the Ria de Aveiro are areas where the residence time is high and cohesive sediments are deposited. Organic...
Protocolos de encaminhamento para redes veiculares com ligações intermitentes
Soares, Vasco N. G. J.; Dias, João A.; Isento, João N.; Rodrigues, Joel J. P. C.As redes veiculares são constituídas por automóveis ou outros meios de transporte equipados com dispositivos de comunicação sem fios, que comunicam diretamente entre si ou com equipamentos de infraestrutura localizados junto às estradas. Nestas redes, o encaminhamento de dados é considerado um grande desafio tendo em conta as topologias de rede altamente dinâmicas, densidade variável, tempos de contacto reduzid...
Solutions for vehicular communications: a review
Soares, V.N.G.J.; Isento, João N.; Dias, João A.; Silva, Bruno M.; Rodrigues, JoelVehicular networks experience a number of unique challenges due to the high mobility of vehicles and highly dynamic network topology, short contact durations, disruption intermittent connectivity, significant loss rates, node density, and frequent network fragmentation. All these issues have a profound impact on routing strategies in these networks. This paper gives an insight about available solutions on relat...
Creation of a vehicular delay-tolerant network prototype
Dias, João A.; Isento, João N.; Silva, Bruno M.; Soares, V.N.G.J.; Ferreira, Paulo S.; Nogueira, António M.D.; Rodrigues, JoelVehicular Delay-Tolerant Network (VDTN) is a new disruptive network architecture where vehicles act as the communication infrastructure. VDTN follows a layered architecture based on control and data planes separation, and positioning the bundle layer under the network layer. VDTN furnishes low-cost asynchronous communications coping with intermittent and sparse connectivity, variable delays and even no end-to-e...
Influence of Aveiro Lagoon heavy metal contents in the adjacent continental she...
Abrantes, I.; Rocha, F.; Vidinha, J.; Dias, João A.A chemical analysis of Al, Ca, Fe, Mg, Cu, Pb, Zn, Cr, Co, Ni and Cd was carried out in 22 surface sediment samples of the continental shelf and upper slope between Espinho and Aveiro (Portugal). To reduce the disturbing effects of grain size, all samples were size-normalized by wet sieving (< 63 mu m). The fine fraction was digested with concentrated acids and analyzed by flame atomic absorption spectrometry. ...
Geochemical characterization of surficial sediments from the southwestern Iberi...
Machado, A.; Rocha, F.; Araujo, M. F.; Vitali, F.; Gomes, C.; Dias, João A.The impact of trace elements (Ba, Nb, Zr, Y, Sr, Rb, Pb, As, Zn, Cu, Ni, Co, Cr, V, La, Ce, Nd, Sm, Eu, Th, Yb and Lu) transported by the Guadiana, Tinto-Odiel and Guadalquivir rivers on sediments from the southwestern Iberian continental shelf has been studied. Shelf surficial sediments from three transects established right in front of the river estuaries were characterized by specific signatures relative to ...