Abstract
We present the disparity map computation core of a hardware system for isolating foreground objects in stereoscopic video streams. The operation is based on the computation of dense disparity maps using block-matching algorithms and two well-known metrics: sum of absolute differences and Census transform. Two sets of disparity maps are computed by taking each of the images as reference so that a consistency check can be performed to identify occluded pixels and eliminate spurious foreground pixels. Taking advantage of parallelism, the proposed architecture is highly scalable and provides numerous degrees of adjustment to different application needs, performance levels and resource usage. A version of the system for 640 x 480 images and a maximum disparity of 135 pixels was implemented in a system based on a Xilinx Virtex II-Pro FPGA and two cameras with a frame rate of 25 fps (less than the maximum supported frame rate of 40 fps on this platform). Implementation of the same system on a Virtex-5 FPGA is estimated to achieve 80 fps, while a version with increased parallelism is estimated to run at 140 fps (which corresponds to the calculation of more than 5.9 x 10(9) disparity-pixels per second).

Abstract
Smart grids aim at ensuring a secure, reliable and efficient operation of power systems and for that purpose they need communications infrastructures capable of meeting different requirements. Current and emerging wireless multi-hop solutions based on standard technologies are strong candidates for communications networks associated and integrated with electric distribution grids but a suitable methodology to evaluate and deploy them is missing. This paper presents a holistic methodology supported by contextual information used to generate different scenarios of distribution grids and to evaluate and deploy wireless communications networks for smart grids. Simulation results show that the methodology is suitable for the evaluation of wireless multi-hop networks in the smart grid context and prove that the performance of such networks meets the expected requirements of different applications.

Abstract
Autonomous Underwater Vehicles and Remotely Operated Vehicles are useful in industries such as offshore Oil and Gas, deep sea mining, and aquaculture, where inspection missions are frequent. While underwater communications are mainly done using acoustic links, retrieving data from these devices to shore is still an open issue, especially when we consider the high cost of satellite communications. In this paper, using ns-3 simulations, we evaluate the ability of the communications solution being developed in the BLUECOM+ project to enable real-time marine data transfer at remote ocean areas. Through the usage of tethered balloons, TV white spaces frequencies, and multi-hop communications, the BLUECOM+ solution enables cost-effective, broadband connectivity to the Internet at remote ocean areas, using standard access technologies such as GPRS/UMTS/LTE and Wi-Fi. Simulation results show an expected range exceeding 100 km from shore using only two nodes at sea, with bitrates over 1 Mbit/s.

Abstract
In this paper we assess the influence of the conductivity of the medium on the radiation characteristics and input impedance of a loop antenna designed for underwater communications. The initial study is based on simulation of the antenna characteristics using FEKO electromagnetic (EM) software. Additionally, an equivalent circuit model of the antenna is also obtained and simulation of the input impedance on ADS software shows good agreement with the EM simulator. It is found that the radiation pattern, of the loop antenna changes significantly with the conductivity of the medium, from freshwater to seawater. The loop antennas were built with baluns and tested in freshwater, where the insertion loss between two identical antennas and the radiation pattern of one of them were also measured. The results show good agreement with the simulations.

Abstract
In this work we propose a method for maximization of the efficiency of an underwater wireless power transfer system that has to cope with load changes, quality factor and coupling coefficient deviations. By means of 3D electromagnetic simulation and numerical computation, parameter analysis is accomplished using different compensation methods, namely series-series, series-parallel and parallel-parallel. Moreover, a linear load profile is assessed as a proof of concept applicable to more complex load behaviours. For this linear load variation a maximum measured average efficiency of 82% was obtained throughout the entire battery state of charge. Electronics and full system considerations are also presented. Finally, a good agreement between theoretical predictions of the proposed method, simulation assessment and measurement results was verified.

Abstract
The radiation characteristics of a dipole antenna when immersed in both fresh and seawater are assessed through simulation and experimental work. Simulations show that the antenna's bandwidth and radiation pattern change with the properties of the medium where it is placed, namely the conductivity of the medium. Two dipoles antennas with current baluns were built and tested experimentally in freshwater. The tests included the measurement of the insertion loss between two identical dipole antennas and their radiation pattern. The results obtained show a good agreement between the simulation and experimental results.