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Several researches in the literature propose mechanisms for locating RFID tags using the RSSI indicator. However, the vast majority of these researches propose two-dimensional (2D) location solutions. In this work, we adopted a matrix composed of physical reference tags and virtual reference tags together with a mobile reader, to promote the localization of RFID tags in three-dimensional (3D) environment. In addition, our research differs from the others since we use mobile RFID reader, a feature that reduces deployment costs as a result of not having to use a set of fixed RFID readers. We developed the mechanism using the Matlab software and the performed experiments, demonstrated that our proposal obtained greater location accuracy, with gains of 46% when compared to the location error of other solutions.

[EN] Routing protocol for low-power and lossy networks is a routing solution specifically developed for wireless sensor networks, which does not quickly rebuild topology of mobile networks. In this article, we propose a mechanism based on mobility entropy and integrate it into the corona RPL (CoRPL) mechanism, which is an extension of the IPv6 routing protocol for low-power and lossy networks (RPL). We extensively evaluated our proposal with a simulator for Internet of Things and wireless sensor networks. The mobility entropy-based mechanism, called CoRPL+E, considers the displacement of nodes as a deciding factor to define the links through which nodes communicate. Simulation results show that the proposed mechanism, when compared to CoRPL mechanism, is effective in reducing packet loss and latency in simulated mobile routing protocol for low-power and lossy networks. From the simulation results, one can see that the CoRPL+E proposal mechanism provides a packet loss reduction rate of up to 50% and delays reduction by up to 25% when compared to CoRPL mechanism., The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was funded by SIDIA Institute of Science and Technology, by Coordenacao de Aperfeicxoamento de Pessoal de Nivel Superior (CAPES), by Fundacao de Amparo a Pesquisa do Estado do Amazonas (FAPEAM)-support programs (Programa Primeiros Projetos (PPP) and Programa de Tecnologia da Informacao na Amazonia (PROTI)-Amazonia-Mobilidade), by Camara Tecnica de Reconstrucao e Recuperacao de Infraestrutura (CT-INFRA) of Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes(MCTI)/Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), and by Secretaria de Estado de Ciencia, Tecnologia e Inovacao Amazonas (SECTI-AM) and Government of Amazon State, Brazil.

Production lines normally present a verification step, which is responsible for warning about defective devices. That step, in digital television (DTV) production lines, often includes a tuning and decoding check, which basically verifies if DTV devices are capable of presenting audio and video. However, poor signal conditions may cause unnecessary rejections, which happen due to very hostile environments. Based on that, the present paper proposes a verification methodology that reports poor signal conditions during tuning tests, with the goal of indicating that the associated check must be executed again. Tests, in a real environment, showed that the proposed approach is effective and efficient, while revealed that less than 40% of the obtained rejections, in a target production line, were indeed caused by hardware problems.