Ultrahigh-frequency (UHF) sensing is one of the most promising techniques for assessing the quality of power transformer insulation systems due to its capability to identify failures like partial discharges (PDs) by detecting the emitted UHF signals. However, there are still uncertainties regarding the frequency range that should be evaluated in measurements. For example, most publications have stated that UHF emissions range up to 3 GHz. However, a Cigré brochure revealed that the optimal spectrum is between 100 MHz and 1 GHz, and more recently, a study indicated that the optimal frequency range is between 400 MHz and 900 MHz. Since different faults require different maintenance actions, both science and industry have been developing systems that allow for failure-type identification. Hence, it is important to note that bandwidth reduction may impair classification systems, especially those that are frequency-based. This article combines three operational conditions of a power transformer (healthy state, electric arc failure, and partial discharges on bushing) with three different self-organized maps to carry out failure classification: the chromatic technique (CT), principal component analysis (PCA), and the shape analysis clustering technique (SACT). For each case, the frequency content of UHF signals was selected at three frequency bands: the full spectrum, Cigré brochure range, and between 400 MHz and 900 MHz. Therefore, the contributions of this work are to assess how spectrum band limitation may alter failure classification and to evaluate the effectiveness of signal processing methodologies based on the frequency content of UHF signals. Additionally, an advantage of this work is that it does not rely on training as is the case for some machine learning-based methods. The results indicate that the reduced frequency range was not a limiting factor for classifying the state of the operation condition of the power transformer. Therefore, there is the possibility of using lower frequency ranges, such as from 400 MHz to 900 MHz, contributing to the development of less costly data acquisition systems. Additionally, PCA was found to be the most promising technique despite the reduction in frequency band information.

Humanoid robots are an extremely complex interdisciplinary research field. Particularly, the development of high size humanoid robots usually requires joint efforts and skills from groups that are in many different research centers around the world. However, there are serious constraints in this kind of collaborative development. Some efforts have been made in order to propose new software frameworks that can allow distributed development with also some degree of hardware abstraction, allowing software reuse in successive projects. However, computation represents only one of the dimensions in robotics tasks, and the need for reuse and exchange of full robot modules between groups are growing. Large advances could be reached if physical parts of a robot could be reused in a different robot constructed with other technologies by other researcher or group. This paper proposes a new robot framework, from now on called TORP (The Open Robot Project), that aims to provide a standard architecture in all dimensions (electrical, mechanical and computational) for this collaborative development. This methodology also represents an open project that is fully shared. In this paper, the first robot constructed following the TORP specification set is presented as well as the advances proposed for its improvement.

This paper presents research and development results of a prototype portable system designed for monitoring and recording HPP (Hydroelectric Power Plant) workplace environment data (noise, vibration, pressure, temperature, gas concentration and light level), related to working health conditions observing the requirements from current national and international standards. This has been achieved by using a series of dedicated sensors connected via wireless network to a portable intelligent computing platform in order to diagnosis the risks which workers are subjected to and also for improving the quality of life at work. The main contributions of this work are highlighted by technological innovation in state of the art of hardware and software components used (sensors, microcontrollers, computer, operating system, etc.), simultaneous multivariate acquisition and recording of environment workplace data, a novel methodology able to measure, record, analyze and diagnose risks, automatic generation of technical reports and risk maps, and creation of an innovative database for planning and following preventive and corrective maintenance actions over workplace conditions. The final product may be used by any company of electricity generation, especially HPP. Furthermore, this system will be of great value to the whole electric power industry, particularly power generation, as it will allow an integrated real-time and continuous monitoring of occupational risks, helping work-related injury and illness preventive actions as a permanent preventive occupational safety and health program, thus resulting in an increasing of quality and reliability aimed for excellence. The research and development prototype was successfully designed, produced and tested through P&D funding from a HPP company at Sao Paulo.

Este artigo descreve um simulador de um processador hipotético simples para a introdução de conceitos de linguagem de montagem em alunos do ensino médio e nível superior. O simulador, desenvolvido para ser utilizado como uma ferramenta didática, oferece ao aluno, em uma interface gráfica, um modelo do funcionamento de um computador do ponto de vista da programação de baixo nível. Nesta ferramenta, o usuário carrega o seu programa em linguagem de máquina e visualiza as mudanças decorrentes da sua execução na memória e nos registradores. Considerando a importância do entendimento da diferença entre linguagem de montagem e linguagem de máquina, o aluno é orientado a escrever seu código em linguagem de montagem e em seguida, fazer a montagem para obter a linguagem de máquina. No início, este procedimento é de forma manual e posteriormente através de um programa montador. A montagem manual esclarece alguns conceitos, relacionados à geração de código executável, escondidos nos ambientes de desenvolvimento integrados. Apesar da ferramenta simular um processador hipotético simplificado, ela foi construída seguindo a sintaxe de instruções usada na arquitetura Intel de 32 bits (IA-32), permitindo que o aluno utilize os conceitos absorvidos quase diretamente no entendimento de outras linguagens de montagem em computadores reais. Esta ferramenta é utilizada introdutoriamente na disciplina Linguagem de Montagem do Curso de Ciência da Computação na Universidade Estadual Paulista em Bauru com significativo aumento da taxa de aprovação dos alunos, a qual pode ser confirmada a partir dos dados apresentados sobre oito anos lecionados, sendo quatro deles com o uso do simulador.