2017
Authors
Aboderin, O; Pessoa, LM; Salgado, HM;
Publication
OCEANS 2017 - ABERDEEN
Abstract
Transmission and reception of high-speed short range signal is important for successful underwater water communications between an Autonomous Underwater Vehicle (AUV) or Remote Operated Vehicles (ROVs) and a docking station or underwater sensor nodes during a survey mission. The need for this form of application is currently receiving global attention from scientific groups and industries. Hence, underwater antennas are therefore required to provide these links and achieve good data rates and propagation distances for these applications either in fresh or sea water scenario. In this paper, the performance of loop antenna placed at a specified distance and parallel to the ground plane is assessed through simulation for usage in fresh water and operating in the High Frequency (HF) band. Three variations of this antenna namely; the circular loop, the square loop and the delta loop antennas has been placed on two different ground plane shapes (circular and square) for analyses of their performances. These antennas were designed in FEKO, an electromagnetic simulation software and their performance is assessed in terms of bandwidth and directivity. The results obtained shows that the antennas exhibit wideband and high directivity with square loop antenna placed on a square ground plane having slight advantages over the other antennas with respect to their bandwidth and directivity. Experimental results added for the same antenna, confirmed its performance in terms of the measured parameters are in good agreement with simulation results.
2017
Authors
Lima, J; Pereira, AI; Costa, P; Pinto, A; Costa, P;
Publication
PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2016 (ICNAAM-2016)
Abstract
This paper describes an optimization procedure for a robot with 12 degrees of freedom avoiding the inverse kinematics problem, which is a hard task for this type of robot manipulator. This robot can be used to pick and place tasks in complex designs. Combining an accurate and fast direct kinematics model with optimization strategies, it is possible to achieve the joints angles for a desired end-effector position and orientation. The optimization methods stretched simulated annealing algorithm and genetic algorithm were used. The solutions found were validated using data originated by a real and by a simulated robot formed by 12 servomotors with a gripper.
2017
Authors
Roque, LAC; Fontes, DBMM; Fontes, FACC;
Publication
4TH INTERNATIONAL CONFERENCE ON ENERGY AND ENVIRONMENT RESEARCH, ICEER 2017
Abstract
The environmental concerns are having a significant impact on the operation of power systems. The traditional Unit Commitment problem (UCP), which minimizes the total production costs is inadequate when environmental emissions need to be considered in the operation of power plants. This paper proposes a metaheuristic approach combined with a non-dominated sorting procedure to find solutions for the multi-objective UCP. The metaheuristic proposed, a Biased Random Key Genetic Algorithm, is a variant of the random-key genetic algorithm, since bias is introduced in the parent selection procedure, as well as in the crossover strategy. (C) 2017 The Authors. Published by Elsevier Ltd.
2017
Authors
Nikolic, B; Pinho, LM;
Publication
REAL-TIME SYSTEMS
Abstract
2017
Authors
Pereira, R; Rodrigues, J; Martins, A; Dias, A; Almeida, J; Almeida, C; Silva, E;
Publication
2017 IEEE International Conference on Autonomous Robot Systems and Competitions, ICARSC 2017
Abstract
This paper presents the work performed in the implementation of an underwater simulation environment for the development of an autonomous underwater vehicle for the exploration of flooded underground tunnels. In particular, the implementation of a laser based structured light system, multibeam sonar and other robot details were addressed. The simulation was used as a relevant tool in order to study and specify the robot multiple sensors characteristics and placement in order to adequately survey a realistic environment. A detailed description of the research and development work is presented along with the analysis of obtained results and the benefits this work brings to the project. © 2017 IEEE.
2017
Authors
Moreira, MRA; Gherman, M; Sousa, PSA;
Publication
INNOVATION-MANAGEMENT POLICY & PRACTICE
Abstract
Innovation is a widely studied field. It is extremely important for any organization wishing to achieve and maintain a competitive advantage in the market, even though assessing the impacts of innovation represents a challenge due to the difficulty of isolating and measuring it. Furthermore, healthcare institutions are facing an increasing need for innovation in order to become competitive and offer new treatments for patients. Surprisingly, little is known about the nature of innovativeness in healthcare organizations and its relationship with performance. The aim of this research is to analyze whether the several types of innovation influence the relevant measures of performance in healthcare institutions, researching empirically the innovativeness-performance relationship. The study is based on a quantitative analysis on 34 Portuguese hospitals, collecting detailed information about the innovation portfolio of each one. Factor analysis and hypothesis testing were applied. Moreover, the hospitals were classified by type of property and geographical region they belong to, and statistical comparative tests were performed to test the existence of statistical differences. It was found that organizational innovation is correlated with process innovation and service innovation. Furthermore, service and process innovations influence operational performance. However, we cannot conclude that innovation in healthcare units has an overall impact on their financial performance. The results of this study may help hospital administrators to make better decisions with regard to their innovation policy design.
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