Detectar pessoas em imagens digitais é uma tarefa recorrente para o desenvolvimento de várias aplicações. O presente trabalho tem o objetivo de propor um método para identificação de pessoas em imagens aéreas com a utilização de VANT para dar suporte ao produtor e aos órgãos especializados no combate ao abigeato. A solução proposta executa processos de criação de mosaicos georreferenciados e classificação de objetos. Para geração dos mosaicos foram testadas a ferramenta OpenDroneMap e o utilitário Web MapsMadeEasy. Também foi estudada a biblioteca open source GDAL. O treinamento dos descritores em cascata foi efetuado com a utilização de um software que apresenta os parâmetros implementados na biblioteca OpenCV em uma interface gráfica, facilitando assim a manipulação dos mesmos. O descritor HOG utilizado é disponibilizado na biblioteca OpenCV. Para fins de teste foram criados dois classificadores Haar e LBP com 8, 15 e 20 estágios, todos fazendo uso do mesmo conjunto de imagens negativas. No entanto, foram gerados classificadores Haar e LBP utilizando um primeiro conjunto de imagens positivos e posteriormente foram gerados outros classificadores Haar e LBP utilizando um segundo conjunto de imagens positivas. Dados os resultados pode-se concluir que as ferramentas de processamento de imagens aéreas geram resultados satisfatórios. Também notou-se que as cascatas de classificadores efetivamente detectam pessoas, porém também geram uma quantidade elevada de falsos positivos. Com os testes realizados, pode-se notar na prática que efetivamente classificadores Haar demandam mais tempo para treinamento, porém sua taxa de acerto é melhor. Também observou-se que a quantidade de estágios de uma cascata deve ser adequadamente dimensionada, já que classificadores com 20 estágios obtiveram resultados muito insatisfatórios, gerando apenas falsos positivos.

Os espaços virtuais proporcionados pela internet, nomeadamente as redes socias virtuais, possibilitam às pessoas estarem presentes virtualmente em tempos e espaços diferentes. Os alunos e os professores também estão inseridos nas redes sociais virtuais e facilmente criam laços de interação social. É importante o professor servir-se das potencialidades das redes sociais virtuais e estudar estratégias de interação entre os alunos nestes espaços de forma a potenciar o processo de ensino e aprendizagem em tempos e espaços diferentes. Neste estudo contextualizou-se o processo de ensino e aprendizagem da disciplina de Informática Aplicada do Instituto Superior de Ciências da Educação da Huíla em Angola. Propôs-se responder a seguinte questão de investigação: Os alunos da disciplina de Informática Aplicada, intensificam as suas interações de aprendizagem mediante um grupo virtual no Facebook na resolução e apresentação das atividades da aula. O objectivo geral deste estudo é descrevermos a intensificação das interações entre alunos por meio de um grupo virtual no Facebook para a resolução e apresentação das atividades da aula. Tratou-se de um estudo de caso. Os participantes do estudo foram os alunos do primeiro ano dos cursos de Química e Física no ano lectivo de 2018. O instrumento de recolha de dados utilizado foi o portfólio do grupo virtual e analisou-se os dados mediante a análise estrutural das redes sociais; Os resultados do estudo permitiu-nos compreender como acontece as interações entre os alunos no ensino e aprendizagem da disciplina de Informática Aplicada no grupo virtual do Facebook.

Although semiconductor devices have progressively replaced vacuum tubes in nearly all applications, vacuum-tube amplifiers are still in use by professional musicians due to their tonal characteristics.  Over the years, many different techniques have been proposed with the goal of reproducing the timbral characteristics of these circuits.  This paper presents a review on the methodologies  that have been used to emulate tube circuits  over the last 30 years for musical applications.  The first part of the paper introduces the basic principles of tube circuits, with a common cathode triode example.  The remainder of the paper reviews the tube sound simulation devices.  The first of these emulations used analog  operational amplifier circuits with the negative feedback designed to reproduce tube transfer. As DSP became more popular over the last decades for audio applications, efforts towards digital tube circuit simulation algorithms were initiated. Simulation of these devices are basically divided into linear models with digital filters that correspond to IIR analog filters and nonlinear digital models that corresponds to the tube circuit itself.  The simulation of the first is straightforward, normally accomplished by the use of FIR digital filters.  The last can be either accomplished approximation equations, that are known as digital waveshapers and their variants or by circuit derived techniques, such as the resolution of circuit ordinary differential equations solvers.  Wave digital filter models are also variants of circuit simulation techniques that are also treated in this paper.  The circuit derived techniques yield more precise simulations over the waveshapers but are always computationally more expensive so that a compromise between accuracy and  efficiency is needed for real-time simulation of these devices.

Information technology has become essential for a better management and competitiveness of organizations. Recently, the agricultural sector has excelled in the search for tools such as computer programs, geographic information systems, electronic data collecting systems, satellite navigation systems, among others. Along with these technologies, new models of temporal data analysis based on chaos theory came to support the nonlinear dynamic analysis of tillage operations such as chiseling and subsoiling. These operations demand high energy and consequently higher operating costs for farmers. Therefore, it is necessary a better evaluation and understanding of these operation dynamics. The objective of this work was to develop a computer program for processing soil mobilization force datum using temporal data analysis AREF (Autoregressive Error Distribution Function). For development of the computer program it was used the VBA (Visual Basic for Applications) language included into all Microsoft Office programs. Computer program enables charting, what permitted the identification of linear patterns in tillage forces as well as identify the parameters of AREF function α (y-axis intercept) and β (slope of the curve) which could subsequently be statistically analyzed. It was observed that the computer program has a simple interface for operation and can be used by agriculture professionals with basic computer knowledge.

A soundscape is the representation of an acoustic environment in a specific context and time. Soundscapes evolve over time according to the changes in social, cultural and political contexts, and they constitute a unique way of experiencing auditory memories of a specific period in history. Considering that the soundscape of a place is ever-changing and it can provide us with important information about a location’s context in time, the study and preservation of soundscapes, in particular historic soundscapes, has gained relevance in the cultural heritage protection and promotion process. Soundscapes enrich the history of places and contribute to enhance the visitors experience in tourism contexts. However, it is impossible to go back in time and record the acoustic experiences from centuries ago. For that reason, the closest we can get to experience an historic soundscape is by trying to recreate it. This can be done with the support of historic documentation and audio immersion technology. We created a solution that allows users to construct scenes that provide immersive auditory experiences. The immersive audio files generated are obtained by combining different current sound recordings, and by composing an immersive auditory scene that can be recorded by the user. Here, we propose Immerscape, a tool that non-expert users can easily use to create immersive historical soundscapes. This work was validated by a user study that evaluated the tool’s functionalities and its acceptance by users. The proposed work is a contribution to the PASEV project, whose main purpose is to preserve and promote Évora’s rich cultural heritage, in particular, their historic soundscapes corresponding to the period between 1540 and 1910.

Lab-based education plays an important role for students adopting science and technology-based careers. The sudden transition to a distance learning environment due to the COVID-19 pandemic and how teachers have tackled with providing lab-based teaching while trying to improve students’ engagement and motivation, is the focus of the presented works. A good diversification of teaching approaches such as PBL, teamwork, gamification or the integration of complementary resources is presented. Additionally, the VISIR+ project is also addressed in the context of a study on Brazil's Educational reality, related to Engineering Education. The VISIR remote lab is also presented as a versatile tool, to be used in several subject areas, other than electronic and electrical circuits.