This work focuses on the characterization of indoor hybrid power line communication (PLC)-wireless channels in the frequency band between 1.7 and 100 MHz. These hybrid channels allow the simultaneous exploitation of the ubiquitous PLC channel and the mobility benefits offered by the wireless signals radiating from and being induced into power cables. A comprehensive study and analysis was conducted based on: (i) coherence time, (ii) additive noise power spectral density, (iii) coherence bandwidth, (iv) delay spread, (v) average channel gain, (vi) channel frequency response and (vii) channel capacity. Based on the reported analysis, the magnitude responses of hybrid PLC-wireless channels can be assumed to be symmetrical and significantly frequency selective. Also, we reveal that additive noise power spectral density and, consequently, channel capacity differ considerably in the PLC-to-wireless and wireless-to-PLC transmission directions. Finally, we show that the measured PLCwireless channels present a channel capacity of up to hundreds mega bits per second.

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This work aims at measuring, characterizing, and analyzing hybrid channels for mobile data communication with power line communication (PLC) technologies. These channels denote the concatenation of power line and wireless as only one channel. A measurement setup and OFDM-based technique for channel estimation were applied to carry out a measurement campaign of hybrid channels in the P LC → wireless and wireless → P LC directions. Preliminary results as well as analysis when estimates of the hybrid channels cover the frequency band between 1.7 up to 100 MHz are presented. The attained results reveals that these hybrid channels are very challenging ones. Also, they could be useful for data communication if more investigation concerning the PLC coupling device, the antenna geometry, and theoretical formulation for the signal propagation through the hybrid channel is deeply investigated.

RESUMOEste artigo trata de mecanismos sociais de decisões judiciais. O objetivo é explicar o processo de tomada de decisões que culminam na aplicação da medida de internação, no âmbito da justiça juvenil. A pesquisa consistiu em um desenho misto explicativo. Em um primeiro momento foram testadas as hipóteses da literatura com uma amostra representativa de adolescentes que passaram pela justiça entre 1990 e 2006. Em seguida, uma corte juvenil foi visitada, tendo sido observadas audiências e oitivas. Os resultados indicam que o mecanismo-padrão da justiça juvenil envolve decisões tomadas a partir dos relatos policiais, criando uma proporcionalidade entre gravidade da infração e severidade da medida aplicada; e que há situações em que a definição da situação é rompida, fazendo com que os operadores tomem medidas mais brandas para jovens brancos, não-usuários de drogas e que estudam ou trabalham. Palavras-chave: Sistema de justiça juvenil; Decisões judiciais; Desenho misto explicativo.