Abstract-Analysis and recognition of objects in complex scenes is a demanding task for a computer. There is a selection mechanism, named visual attention, that optimizes the visual system, in which only the important parts of the scene are considered at a time. In this work, an object-based visual attention model with both bottom-up and top-down modulation is applied to the humanoid robot NAO to allow a new attention procedure to the robot. This means that the robot, by using its cameras, can recognize geometric figures even with the competition for the attention of all the objects in the image in real time. The proposed method is validated through some tests with 13 to 14 year old kids interacting with the robot NAO that provides some tips (such as the perimeter and area calculation formulas) and recognizes the figure showed by these children. The results are very promissor and show that the proposed approach can contribute for inserting robotics in the educacional context.
In nature, we can find spectacular optical phenomena exhibited by some material when interacting with light. Complex nanostructures that have evolved to perform specific functions, such as camouflage and preservation of such materials. These structures are so sophisticated that we are, until the present time, looking for the fundamentals of those unique and interesting natural phenomena exhibited by them. Therefore, to understand all the effects related to those structures, it is necessary to combine knowledge from different scientific areas. In this report, we study the structural color observed on the wing samples of Quesada gigas, Greta oto, and Morpho cypris; three native species from South America. The optical effect observed on their wings is due to the particular photonic structure arrays present on their composition. Our interest is mainly to understand how the structural disorder influences the light interaction and consequences. For this purpose, we performed interferometric measurements, used spatiotemporal measurement that can indicate localization of light, and computational methods based on Maxwell-Bloch equations, transfer matrix and Kronig-Penney model. Here we present the results of our measurements and calculations. These results come up with promissory evidence that it is possible to measure the peculiar response of the photonic systems when the light interacts with the presence of disorder introduced in the structure on samples of natural origin. Therefore, in this work we suggest one way to detect Anderson localization in natural photonic structures. Those results allowed us to establish a correlation for similar behavior observed in electronic systems by Anderson and apply it in photonic crystals known as the light semiconductors.
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