In this paper we propose a new time difference delay of arrival technique based on the semblance multichannel coherency function for the problem of sound source localization. The proposed algorithm was tested on recordings from an Unmanned Aerial Vehicle (UAV) equipped with an array of 8 microphones, for estimating the azimuth and elevation angles of a speech based source. Our results shown that the semblance method has proven to have a good performance, obtaining good results regardless of the ego noise even in cases where the signalto-noise ratio (SNR) was very low.

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Several studies are focused on the study of code smells and many detection techniques have been proposed. In this scenario, the use of rules involving software-metrics has been widely used in refactoring tools as a mechanism to detect code smells automatically. However, actual approaches present two unsatisfactory aspects: they present a low agreement in its results and, they do not consider the developers' feedback. In this way, these approaches detect smells that are not relevant to the developers. In order to solve the above mentioned unsatisfactory aspects in the state-of theart of code smells detection, we propose the Smell Platform able to recognize code smells more relevant to developers by using its feedback. In this paper we present how such platform is able to detect four well known code smells. Finally, we evaluate the Smell Platform comparing its results with traditional detection techniques.

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Abstract:The silver oxide nanoparticles (AgONps) used in this study was obtained by laser ablation technique. On the other hand, graphene bilayers were obtained through micro mechanic exfoliation. Both techniques are considered clean, simple and they have economic viability. The analyses have showed a positive charge in nanoparticles and alteration in Raman spectra caused by doping in the bilayer observing the appearing of D band. The alterations in the Raman spectrums are related with the introduced defects in the crystalline chain after the nanoparticles incorporation on bilayers. However, we have been doing a systematic study about the Raman laser output in only graphene bilayer and in graphene bilayer doped with nanoparticles. These measurements have shown a clear difference to both cases. The distance between defects has been showing to be inversely proportional to the ratio I D /I G in the analyzed cases, increasing (up power) or lowering (down power) the incident laser output, with this it was possible to handle the defect distances in the case of AgO nanoparticles/graphene bilayers. Finally, we analyzed the ratio of the integrated area of D and G band, from these parameters are determined the defect density (N D ) and the defects density (L D ). Thus, we clearly find a tuning between the N D and L D as a function of laser power density Raman using to  = 532 nm.

Em uma ciência cada vez mais orientada a dados, o uso de métodos computacionais inteligentes é progressivamente indispensável. Neste contexto, torna-se importante expor os estudantes de graduação em física às metodologias de inteligência artificial e aprendizado de máquina. Neste trabalho propomos uma forma de utilizar tais métodos na física, resolvendo o problema didático do rolamento em um plano inclinado. Para tanto, introduzimos os principais conceitos das técnicas de aprendizado de máquina e realizamos medidas do tempo que diferentes objetos (aro, disco e esfera) levam para percorrer uma certa distância, de acordo com a altura inicial e o ângulo de inclinação do plano. Com estes dados, aplicamos métodos de classificação capazes de predizer o objeto que rolava sobre o plano com acurácia de 83%, e métodos de regressão capazes de prever a velocidade média do objeto com erro absoluto médio de 1.4 cm s−1. Mostramos também que este modelo didático é instrutivo pois possibilita uma comparação direta com modelos físicos tradicionais e serve como exemplo introdutório para a discussão do que significa ensinar física para o computador.

We built a magnetic stirrer to mix tea and honey and developed a method to determine the homogeneity of the mixture based on the variation of light intensity of a laser beam with time due to its scattering by the mixture. The addressed problem was that of mixing tea and honey as fast as possible with a power limitation of one single 1.5 V battery, following the statement of Problem 15 of the 9th International Physicists’ Tournament. The influence of temperature and honey concentration on the total time of mixing was studied through the performance of several experiments reported here. In the best configuration of parameters, the total mixture occurs in less than 2 s, while in the worst configuration, the time necessary reaches 10 s. Results validate the magnetic stirrer as a proper device for mixing tea with honey and light attenuation as an excellent physical property for investigating the homogeneity of the mixture of the honey in tea. Supplementary investigations were made exploring the influence of adding sugar and or a slice of lemon to the tea.