Da Genealogia da mais-valia à realização da crítica da economia política

XX Encontro Nacional de Economia Política: desenvolvimento Latino-Americano, Integração e Inserção Internacional - UNILA, Foz do Iguaçu, 26 a 29 de maio de 2015Este artigo pretende demonstrar a singularidade da crítica da economia política realizada por Marx como superação da crítica fi losófi ca na qual foi formado, pela afi rmação da centralidade das determinações materiais da vida social. Nesse processo, foi central a reconfi guração da dialética hegeliana empreendida por Marx, sintetizada na descoberta da categoria mais-valia. A genealogia desta categoria será sumariamente reconstituída mediante o exame do itinerário teórico de Marx, desde os anos como jornalista na Gazeta Renana até o momento de sua descoberta nos Grundrisse. A mais-valia é entendida, pois, como ponto fulcral de um longo processo de investigações movido tanto por uma insatisfação com a fi losofi a de seu tempo, quanto pela motivação político-ideológica de transformação socialista do mundo, representando a categoria-síntese, o núcleo fundamental da crítica da economia política, a partir do qual a essência da sociedade capitalista pôde ser reveladaBanco Nacional de Desenvolvimento Econômico e Social (BNDES); Usina Hidrelétrica de Itaipu (ITAIPU); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) e Universidade Federal da Integração Latino-Americana (UNILA

Neural Network Detection of Fatigue Crack Growth in Riveted Joints Using Acoustic Emission

The purpose of this research was to demonstrate the capability of neural networks to discriminate between individual acoustic emission (AE) signals originating from crack growth and rivet rubbing (fretting) in aluminum lap joints. AE waveforms were recorded during tensile fatigue cycling of six notched and riveted 7075-T6 specimens using a broadband piezoelectric transducer and a computer interfaced oscilloscope. The source of 1,311 signals was identified based on triggering logic, amplitude relationships, and time of arrival data collected from the broad-band transducer and three additional 300 Hz resonant transducers bonded to the specimens. The power spectrum of each waveform was calculated and normalized to correct for variable specimen geometry and wave propagation effects. In order to determine the variation between individual signals of the same class, the normalized spectra were clustered onto a two-dimensional feature space using a Kohonen self organizing map (SOM). Then 132 crack growth and 137 rivet rubbing spectra were used to train a back-propagation neural network to provide automatic pattern classification. Although there was some overlap between the clusters mapped in the Kohonen feature space, the trained back-propagation neural network was able to classify the remaining 463 crack growth signals with a 94% accuracy and the 367 rivet rubbing signals with a 99% accuracy

Desenvolvimento de equipamento de manipulação de objectos deformáveis e a sua interacção com uma máquina de injecção de plásticos

In this project, our objective was to thoroughly investigate the feasibility of automating a process at Ficocables by integrating a robotic arm. Specifically, we focused on automating the joining of two separate processes while eliminating the need for manual intervention in the second operation. The equipment involved in the process includes a Roboco Zamak injection machine and a Babyplast polymer injection machine. With well-defined project requirements, we explored various solutions and sought guidance from Fluidotronica, a renowned expert in this domain. With their support, we identified the collaborative robot JAKA Zu 3s, equipped with a long-finger gripper, as the optimal solution for our needs. To assess the financial viability, we conducted a meticulous financial analysis using methods like NPV and payback period, both of which demonstrated promising results. Although the implementation of the robotic arm is still pending, the outcomes of our study highlight its remarkable versatility for future applications within Ficocables. This project exemplifies the potential advantages of automation and offers valuable insights for forthcoming initiatives in this field.Neste projeto, o objetivo era investigar exaustivamente a viabilidade de automatizar um processo na Ficocables através da integração de um braço robótico. Especificamente, concentrámo-nos em automatizar a junção de dois processos separados, eliminando a necessidade de intervenção manual na segunda operação. O equipamento envolvido no processo inclui uma máquina de injeção de Zamak, denominada Robocop e uma máquina de injeção de polímero denominada Babyplast. Com os requisitos de projeto bem definidos, explorámos várias soluções e procurámos orientação junto da Fluidotronica, um especialista de renome neste domínio. Com o seu apoio, identificámos o robô colaborativo JAKA Zu 3s, equipado com uma pinça de dedos longos como a solução ideal para as necessidades deste projeto. Para avaliar a viabilidade financeira, efetuou-se uma análise financeira meticulosa utilizando métodos como o NPV e o período de retorno do investimento, tendo ambos demonstrado resultados promissores. Embora a implementação do braço robótico ainda esteja pendente, os resultados do nosso estudo destacam a sua notável versatilidade para futuras aplicações na Ficocables. Este projeto exemplifica as vantagens potenciais da automatização e oferece uma visão valiosa para iniciativas futuras neste domínio

Student Satisfaction in Polytechnic Higher Education: Assessment Model Based on the ECSI Index

The assessment of student satisfaction is an integral part of the concerns of those responsible for Higher Education Institutions. Therefore, the main objective of this study is to identify the determinants of students' satisfaction in Polytechnic Higher Education. The study was based on ECSI (European Customer Satisfac-tion Index). The methodology was based on the application of a survey with a sample of 361 Polytechnic students, in order to understand which attributes stu-dents most value in a higher education institution. The results show that the at-tributes that most contribute to the students' satisfaction are, in order of im-portance, the expectations, the quality and perceived values and the image, all pre-senting statistically significant values. In turn, satisfaction is the variable that most influences loyalty, which is also influenced by image and complaint resolution. The levels of global satisfaction towards the Higher Education Institutions ana-lysed are significantly lower than the levels of other sectors, also studied in Por-tugal through this same methodology.info:eu-repo/semantics/publishedVersio

Literatura engajada em língua portuguesa: Cabo Verde, Brasil e Portugal no século XX

Este artigo objetiva traçar um perfil das produções engajadas das literaturas de Cabo Verde, Brasil e Portugal no século XX, destacando alguns de seus autores, bem como certos pontos de convergência, influência e confluência entre os três sistemas.

Study of age-related changes in postural control during quiet standing through Linear Discriminant Analysis

<p>Abstract</p> <p>Background</p> <p>The human body adopts a number of strategies to maintain an upright position. The analysis of the human balance allows for the understanding and identification of such strategies. The displacement of the centre of pressure (COP) is a measure that has been successfully employed in studies regarding the postural control. Most of these investigations are related to the analysis of individuals suffering from neuromuscular disorders. Recent studies have shown that the elderly population is growing very fast in many countries all over the world, and therefore, researches that try to understand changes in this group are required. In this context, this study proposes the analysis of the postural control, measured by the displacement of the COP, in groups of young and elderly adults.</p> <p>Methods</p> <p>In total 59 subjects participated of this study. They were divided into seven groups according to their age. The displacement of the COP was collected for each subject standing on a force plate. Two experimental conditions, of 30 seconds each, were investigated: opened eyes and closed eyes. Traditional and recent digital signal processing tools were employed for feature computation from the displacement of the COP. Statistical analyses were carried out in order to identify significant differences between the features computed from the distinct groups that could allow for their discrimination.</p> <p>Results</p> <p>Our results showed that Linear Discrimination Analysis (LDA), which is one of the most popular feature extraction and classifier design techniques, could be successfully employed as a linear transformation, based on the linear combination of standard features for COP analysis, capable of estimating a unique feature, so-called <it>LDA-value</it>, from which it was possible to discriminate the investigated groups and show a high correlation between this feature and age.</p> <p>Conclusion</p> <p>These results show that the analysis of features computed from the displacement of the COP are of great importance in studies trying to understand the ageing process. In particular, the <it>LDA-value </it>showed to be an adequate feature for assessment of changes in the postural control which can be related to functional changes that occur over the ageing.</p

FATORES ASSOCIADOS À AUTOPERCEPÇÃO NEGATIVA DE SAÚDE EM ESCOLARES

The study aimed to estimate the prevalence of negative self-perception of health and associated factors in schoolchildren. This is an epidemiological, cross-sectional study, part of a monitoring of health risk behaviors with high school students living in Jequié/BA, Brazil. The sample was random, proportional by clusters in two stages. The dependent variable was negative self-perception of health, and the independent variables were sociodemographic and lifestyle. A total of 1,170 schoolchildren participated in the study and the reported prevalence of negative health perception was 37.6% higher for females (n=261). After regression analysis, the variables that remained associated with negative health were: being female with a higher probability of the outcome for those with higher inadequate consumption of vegetables (1.5; 95%CI: 1.21-1.87; p=0.00). Among males, the increase in negative health perception is for those who are insufficiently active (1.41; 95%CI: 1.01-1.96; p=0.04) and who spend more than two hours in front of a computer/ video game (1.54; 95%CI: 1.14-2.1; p=0.00). Therefore, inadequate consumption of vegetables by girls and low levels of physical activity and screen time longer than two hours for boys are associated with a negative perception of health. These findings demonstrate the need to develop actions aimed at promoting healthy habits in the school environment.El estudio tuvo como objetivo estimar la prevalencia de autopercepción negativa de la salud y factores asociados en escolares. Se trata de un estudio epidemiológico, transversal, exclusivamente de seguimiento del comportamiento de riesgo medio para la salud escolar, residente en Jequié/BA, Brasil. La muestra fue aleatoria, proporcional a los conglomerados en dos años. La variable dependiente de la autopercepción negativa de la salud, y tan independiente como la sociodemográfica y el estilo de vida. Participaron del estudio 1.170 escolares y la prevalencia negativa de percepción de salud fue un 37,6% mayor para el sexo femenino (n=261). Análisis de consumo, como variables que se asociaron a la salud mayoritaria con mayor probabilidad de consumo fueron: Después del consumo 1.2111: 1.211; p=0,00). En el sexo masculino o en el aumento de la percepción negativa de la salud, es para aquellos que son excepcionalmente activos (1,41; IC95%: 1,01-1,96; p=0,04) y que pasan más de dos horas frente al ordenador/videojuego (1,54; IC95%: 1,14-2,1; p=0,00). Por lo tanto, el consumo inadecuado de vegetales por parte de las niñas y los bajos niveles de actividad física y tiempo de pantalla mayor a dos horas por parte de los niños se asocian con una percepción negativa de la salud. Estos hallazgos demuestran la necesidad de desarrollar acciones encaminadas a la promoción de hábitos saludables en el ámbito escolar.O estudo teve como objetivo estimar a prevalência de autopercepção negativa de saúde e os fatores associados em escolares. Trata-se de um estudo epidemiológico, transversal, integrante de um monitoramento de comportamentos de risco à saúde com escolares do ensino médio, residentes em Jequié-BA, Brasil. A amostra foi aleatória, proporcional por conglomerados em dois estágios. A variável dependente foi a autopercepção negativa de saúde, e as independentes as sociodemográficas e estilo de vida. Participaram do estudo 1.170 escolares e a prevalência relatada de percepção de saúde negativa foi 37,6% maior para o sexo feminino (n=261). Após análise de regressão, as variáveis que se mantiveram associadas à saúde negativa foram: ser do sexo feminino com maior probabilidade do desfecho para aquelas que apresentam maior consumo inadequado de verduras (1,5; IC95%: 1,21-1,87; p=0,00). Já no sexo masculino o aumento de percepção negativa de saúde é para aqueles insuficientemente ativos (1,41; IC95%: 1,01-1,96; p=0,04) e que passam mais de duas horas à frente de computador/videogame (1,54; IC95%: 1,14-2,1; p=0,00). Logo, a prevalência de autopercepção de saúde encontra-se entre os valores identificados na literatura, e os fatores associados foram o consumo inadequado de verduras pelas meninas e baixos níveis de atividade física e tempo de tela maior que duas horas para os meninos