In mobile robotics, the exploration task consists of navigating through an unknown environment and building a representation of it. The mobile robot community has developed many approaches to solve this problem. These methods are mainly based on two key ideas. The first one is the selection of promising regions to explore and the second is the minimization of a cost function involving the distance traveled by the robots, the time it takes for them to finish the exploration, and others. An option to solve the exploration problem is the use of multiple robots to reduce the time needed for the task and to add fault tolerance to the system. We propose a new method to explore unknown areas, by using a scene partitioning scheme and assigning weights to the frontiers between explored and unknown areas. Energy consumption is always a concern during the exploration, for this reason our method is a distributed algorithm, which helps to reduce the number of communications between robots. By using this approach, we also effectively reduce the time needed to explore unknown regions and the distance traveled by each robot. We performed comparisons of our approach with state-of-the-art methods, obtaining a visible advantage over other works.

Training through Multi-modal Collaborative Virtual Laboratory (MMCVL) aims at developing or improving skills of students without the need of them being physically present. MMCVL addresses the problems faced by the current education system such as lack of resources and safe use of expensive laboratory equipment. It also provides a means for easy collaboration between students and teachers from different universities and schools. Multimedia data in terms of 3D mesh, skeleton, audio and virtual object physics interaction are incorporated in MMCVL to provide a 3D Tele-Immersion environment. The system uses low-cost RGB-D cameras such as Microsoft Kinect V2 to capture and generate 3D model of the person by extracting him/her from the entire captured data and immersing it in different interactive virtual environments. Different lab environments can be virtually created to provide for and replace the real laboratories. Object interactions allow for users to interact with the virtual objects present in the scene similar to real lab setup. Recording module of the toolkit allows future reference for training and testing of the student. The system also facilitates virtual feedback by giving the correct measurements, video demonstrations as well as audio communication with the collaborating teacher. Two different Chemistry experiments were performed to evaluate the user experience and usability aspects of MMCVL. Results obtained from the user study analysis prove the system to be fun and realistic, and at the same time engaging and motivating for learning laboratory experiments.

Color image segmentation largely depends on the color space chosen. Furthermore, spaces that show perceptual uniformity seem to outperform others due to their emulation of the human perception of color. We evaluate three perceptual color spaces, CIELAB, CIELUV, and RLAB, in order to determine their contribution to natural image segmentation and to identify the space that obtains the best results over a test set of images. The nonperceptual color space RGB is also included for reference purposes. In order to quantify the quality of resulting segmentations, an empirical discrepancy evaluation methodology is discussed. The Berkeley Segmentation Dataset and Benchmark is used in test series, and two approaches are taken to perform the experiments: supervised pixelwise classification using reference colors, and unsupervised clustering using k-means. A majority filter is used as a postprocessing stage, in order to determine its contribution to the result. Furthermore, a comparison of elapsed times taken by the required transformations is included. The main finding of our study is that the CIELUV color space outperforms the other color spaces in both discriminatory performance and computational speed, for the average case.