Abstract
Virtual Reality environments are able to other natural interaction metaphors. However, it is dicult to accurately place virtual objects in the desired position and orientation using gestures in mid-air. Previous research concluded that the separation of degrees-of-freedom (DOF) can lead to beer results, but these benets come with an increase in time when performing complex tasks, due to the additional number of transformations required. In this work, we assess whether custom transformation axes can be used to achieve the accuracy of DOF separation without sacricing completion time. For this, we developed a new manipulation technique, MAiOR, which oers translation and rotation separation, supporting both 3-DOF and 1-DOF manipulations, using personalized axes for the laer. Additionally, it also has direct 6-DOF manipulation for coarse transformations, and scaled object translation for increased placement. We compared MAiOR against an exclusively 6-DOF approach and a widget-based approach with explicit DOF separation. Results show that, contrary to previous research suggestions, single DOF manipulations are not appealing to users. Instead, users favored 3-DOF manipulations above all, while keeping translation and rotation independent. © 2017 Copyright held by the owner/author(s).

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.

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.

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.

Abstract

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.