Abstract
This paper puts forth projections designs for compressive classification of Gaussian mixture models. In particular, we capitalize on the asymptotic characterization of the behavior of an (upper bound to the) misclassification probability associated with the optimal Maximum-A-Posteriori (MAP) classifier, which depends on quantities that are dual to the concepts of the diversity gain and coding gain in multi-antenna communications, to construct measurement designs that maximize the diversity-order of the measurement model. Numerical results demonstrate that the new measurement designs substantially outperform random measurements. Overall, the analysis and the designs cast geometrical insight about the mechanics of compressive classification problems.

Abstract

Abstract
The adoption of NAO humanoid robots in the RoboCup Standard Platform League (SPL) broguht a new set of challenges on this league on the computer vision area. This paper presents a new color indexing mode and a study of the impact of the reduction of the color spectrum, to be processed on the classification, segmentation and object detection, in a NAO robot, playing on the SPL league. The experiments were performed in the context of the Portuguese Team concluding that a 21 bit look-up table may replace the current 24 bit table used.

Abstract

Abstract
This PhD work has the goal to develop an inexpensive, easily deployable and widely compatible localization system for indoor use, suitable for pre-installed public address sound systems, avoiding costly installations or significant architectural changes in spaces. Using the audible sound range will allow the use of low cost off-the-shelf equipment suitable for keeping a low deployment cost. The state-of-the-art presented in this paper evidences a technological void in low-cost, reliable and precise localization systems and technologies. This necessity was also confirmed by the authors in a previous project (NAVMETRO (R)) where no suitable technological solution was found to exist to overcome the need to automatically localize people in a public space in a reliable and precise way. Although research work is in its first steps, it already provides a thorough view on the problem while discussing some possible approaches and predicting strategies to overcome the key difficulties. Some experiments were already conducted validating some initial premises and demonstrating how to measure the signal's time-of-flight necessary to infer on distance calculations.

Abstract
Phase-sensitive optical time domain reflectometry (phi OTDR) is a simple and effective tool that allows the distributed monitoring of vibrations along single-mode fibers. In this letter we study the effects of modulation instability (MI) in long-range phi OTDR over conventional optical fibers. We demonstrate both theoretically and experimentally that MI can induce a position-dependent signal fading which leads to a nearly complete visibility loss in the interference signal recorded at certain positions and therefore to a sensitivity loss at these positions. While this effect is detrimental in the context of distributed vibration analysis using phi OTDR, we also believe that the technique provides a clear and insightful way to evidence the Fermi-Pasta-Ulam (FPU) recurrence associated to the MI process.