On the Smarandache Paradox

The Smarandache Paradox is a very interesting paradox of logic because it has a background common sense. However, at the same time, it gets in a contradiction with itself. Although it may appear well cohesive, a careful look on the science definition and some logic can break down this paradox showing that it exist only when we are trying to mix two different universes, where in one we have two possibilities and in the other we have only one. When we try to understand the second possibility in the universe which has only one possibility, we end in the Smarandache Paradox

Correlation of inflation-produced magnetic fields with scalar fluctuations

If the conformal invariance of electromagnetism is broken during inflation, then primordial magnetic fields may be produced. If this symmetry breaking is generated by the coupling between electromagnetism and a scalar field---e.g. the inflaton, curvaton, or the Ricci scalar---then these magnetic fields may be correlated with primordial density perturbations, opening a new window to the study of non-gaussianity in cosmology. In order to illustrate, we couple electromagnetism to an auxiliary scalar field in a de Sitter background. We calculate the power spectra for scalar-field perturbations and magnetic fields, showing how a scale-free magnetic field spectrum with rms amplitude of ~nG at Mpc scales may be achieved. We explore the Fourier-space dependence of the cross-correlation between the scalar field and magnetic fields, showing that the dimensionless amplitude, measured in units of the power spectra, can grow as large as ~500 H_I/M, where H_I is the inflationary Hubble constant and M is the effective mass scale of the coupling.Comment: 11 pages, 3 pdf figure

Unsupervised Learning Applied to the Segmentation of Users of Online Gambling Platforms in Portugal - The effects of the Covid-19 Pandemic on User Behavior and Segmentation

Project Work presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Data ScienceOnline gambling has become an increasingly relevant activity in the last years and is now available through a wide variety of technologies and platforms. This can be seen as an important addition to the entertainment industry since it has the potential of generating great economic impacts. The phenomenon, however, is not free of concerns considering that, like in any other type of gambling activities, online gamblers are susceptible to developing behavioral addiction. This has become a reason of concern to many governmental bodies around the world which are studying this issue due to its social impacts on the population. In this context machine learning algorithms can be applied to understand the behavior of online gamblers and to identify the characteristics of gambling addiction. This work project has the objective of segmentizing users of online gambling platforms in Portugal according to the tendency of these users to have compulsive gambling behavior. It also intends to evaluate the impacts of the Covid-19 pandemic on online gambling addiction by analyzing changes in user segmentation during the initial periods of the pandemic. This will be done by applying unsupervised learning algorithms, specifically K-Means and Self-Organizing Maps and by comparing user clusters from the years 2019 and 2020

The hermite scheme: an application to the n-body problem

In the past century, computational methods have been being applied more and more to physical systems, in special to systems which are chaotic in nature or don’t have an analytical solution, or both, such as is the case for systems that obey the N-body problem. To solve such systems, it is necessary to select the most suitable numerical method, one that takes into account both the necessary time and computational resources available to the researcher, and in order to be able to do so, one must have a good set of tools available. In this work we present a numerical method known as the Hermite Scheme, a fourth-order predictor-corrector integrator which makes use of an Individual Time Step structure, making it capable of processing multi-scale systems. We test its accuracy and study its applicability to the N-body problem, extending the result to chaotic systems in general. We then proceed to check its performance for a N-body system, and compare it to the performance of another fourth-order integrator, the Runge-Kutta. Lastly we verify its performance to multi-scale systems by reproducing some real-life results. Our results show that the Hermite Scheme has a good applicability to N-body systems, with an overall performance better than the fourth order Runge-Kutta. It also shows a good performance when applied to multi-scale systems, with no harm to its overall time performance, which can be applied to other multi-scale systems other than the N-body problem. With this verification, we intend to further apply this method to collision processes and apply the final result on the study of planet formation. The method also shows great potential applicability to Condensed Matter Physics, and we intend to test-apply to known systems in the future.No último século, métodos computacionais vem sendo aplicados mais e mais a problemas físicos, em especial àqueles que ou são caóticos ou não possuem solução analítica, ou ambos, como é o caso de sistemas que obedecem ao problema de N-corpos. Para resolver tais problemas, é necessário selecionar o método numérico mais adequado, um que leve em consideração ambos o tempo necessário e os recursos computacionais disponíveis ao pesquisador responsável; e para que ele seja capaz de fazê-lo, é necessário que ele tenha uma ampla gama de ferramentas disponíveis. Neste trabalho, mostraremos um método numérico conhecido como o Esquema de Hermite, um integrador de quarta ordem preditor- corretor que faz uso de uma estrutura de Passo de Tempo Individual, tornando-o capaz de processar sistemas em multiescalas. Nós testamos sua precisão e estudamos sua aplicação ao problema de N-corpos, estendendo o resultado a sistemas caóticos em geral. Em seguida, verificamos seu desempenho para um sistema de N-corpos e comparamos o resultado com o desempenho de outro integrador de quarta ordem, o Runge-Kutta. Por último nós reproduzimos resultados reais para verificamos seu desempenho em sistemas multiescala. Nossos resultados mostram que o Esquema de Hermite possui uma boa aplicabilidade para sistemas de N-corpos, com um desempenho ao todo melhor do que um Runge-Kutta de quarta ordem. Ele também apresenta um bom desempenho quando aplicado a sistemas multiescala, com nenhum prejuízo à sua performance temporal total, demonstrando que pode ser aplicado a sistemas multiescala que não somente o problema de N-corpos. Com estas verificações, pretendemos no futuro aplicar este método a sistemas com processos de colisão, e aplicar o resultado final no estudo de formação planetária. O método também apresenta grande potencial para aplicação em sistemas de Física da Matéria Condensada, nos quais pretendemos testar a aplicação do método em sistemas conhecidos no futuro.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Correlation of Inflation-Produced Magnetic Fields with Scalar Fluctuations

If the conformal invariance of electromagnetism is broken during inflation, then primordial magnetic fields may be produced. If this symmetry breaking is generated by the coupling between electromagnetism and a scalar field—e.g. the inflaton, curvaton, or Ricci scalar—then these magnetic fields may be correlated with primordial density perturbations, opening a new window to the study of non-Gaussianity in cosmology. In order to illustrate, we couple electromagnetism to an auxiliary scalar field in a de Sitter background. We calculate the power spectra for scalar-field perturbations and magnetic fields, showing how a scale-free magnetic-field spectrum with rms amplitude of ∼nG at Mpc scales may be achieved. We explore the Fourier-space dependence of the cross correlation between the scalar field and magnetic fields, showing that the dimensionless amplitude, measured in units of the power spectra, can grow as large as ∼500HI/M, where HI is the inflationary Hubble constant and M is the effective mass scale of the coupling

Body education and school hygiene in Rio de Janeiro press (1930 - 1939)

In the 1930s in Rio de Janeiro, there was an effective presence of intellectuals in government positions, which could ensure the implementation of a number of strategies aimed at the construction of a wider reform of a society guided by modernity, which lay in the reform of habits, such as hygiene and body education. Rio de Janeiro was the administrative center of the republic, so there was a need for coordinating government policy on education and health, especially in that city. This study has aimed to evaluate the influence and impact of hygienist strategies on the daily life of schools. Its sources were mainly O Paiz and Jornal do Brazil newspapers in the 1930s. The document corpus consisted of 37 newspaper articles, of which 21 were analyzed in this research, because they involved the following specific categories: school medicine, school hygiene and health education. The hypothesis pointed to the limited influence of intellectuals, with a gap between what was thought and what was executed. However, findings allow us to consider approaching the educational discourses and practices influenced by the actual participation of intellectuals such as Fernando de Azevedo and Anísio Teixeira in the organization of education in Rio de Janeiro, particularly in the early 1930s.No Rio de Janeiro, na década de 1930, uma presença mais efetiva de intelectuais em cargos governamentais poderia garantir a efetivação de uma série de estratégias que visava à construção de uma reforma mais ampla da sociedade pautada pela modernidade, que residia também nas reformas de hábitos, como a higiene e a educação do corpo. Sendo o Rio de Janeiro, o centro administrativo da República, haveria a necessidade de articulação entre as políticas governamentais no âmbito da educação e saúde sobretudo naquela cidade. Na análise desse contexto, este estudo teve como objetivo avaliar a influência e o impacto de estratégias higienistas sobre o cotidiano das escolas. O estudo teve como fontes, principalmente, os jornais O Paiz e o Jornal do Brasil no período de 1930 a 1939. O corpo documental foi composto por 37 artigos de jornal, sendo que 21 foram analisados nesta pesquisa, pois envolviam as categorias específicas medicina escolar , higiene escolar e educação higiênica . A hipótese versava sobre uma influência limitada dos intelectuais, havendo uma distância entre o que era pensado e o que era executado. Contudo, os resultados obtidos permitem considerar uma aproximação entre os discursos e as práticas pedagógicas influenciada pela participação efetiva de intelectuais como Fernando de Azevedo e Anísio Teixeira, por exemplo, na organização da educação no Rio de Janeiro, sobretudo no início da década de 1930.42241142

The curse of technological race: the red queen effect

Economic prosperity is tied to scientific development, i.e., there is a strong correlation between science, technology and the wealth of nations. We collected data from scientific and technological production of 183 countries of the last thirty years (1974 to 2003) and applied a super-paramagnetic clustering technique on them, finding nations divided in three regimes, distinguished by the interactions between the agents of their National Systems of Innovation (NSI). The identification of these groups allows us to define the dynamical behavior of the thresholds, that grow exponentially and whose growth rate we have calculated. We show that for the period 1974-2003 the threshold between the immature and the developed NSIs increases by an annual rate of 6.6% (per capita). We identify clearly a "Red Queen Effect". Finally we show that the transitions between the regimes are discontinuous, represented by a structural breakthrough. Therefore, the prerequisite to move from regime I to regime II, and then to regime III are structural changes within NSIs.national systems of innovation; super-paramagnetic clustering technique; moving thresholds

Matrices of science and technology interactions: implications for development

Scientific and other non-patent references (NPRs) in patents are important tools to analyze interactions between science and technology. This paper organizes a database with 514,894 USPTO patents granted globally in 1974, 1982, 1990, 1998 and 2006. There are 165,762 patents with at least one reference to science and engineering (S&E) literature, and there are 1,375,503 references. In 2006 there are 83 countries with USPTO patent citing S&E literature. Through a lexical analysis 71.1% of this S&E literature is classified by S&E fields. These data underscore the elaboration of global and national tri-dimensional matrices (by OST technological domains, ISI science and engineering fields and number of references). Descriptive statistics investigate how science and technology linkages differ over time across countries and across levels of development. This paper highlights how the existence (or not) of a pattern of structured growth differentiates mature and immature systems of innovation.science and technology linkages, stages of economic development, systems of innovation

Modeling economic growth fuelled by science and technology

This paper suggests a simulation model to investigate how science and technology fuel economic growth. This model is built upon a synthesis of technological capabilities represented by national innovation systems. This paper gathers data of papers and patents for 183 countries between 1999 and 2003, GDP and population for 2003. These data show a strong correlation between science, technology and income. Three simulation exercises are performed. Feeding our algorithm with data for population, patents and scientific papers, we obtain the world income distribution (R=0.99). These results support our conjecture on the role of science and technology as a source of the wealth of nations.simulation models; systems of innovation; economic growth

possibilidades literárias na produção visual: imbricações e apontamentos

O presente artigo aborda as etapas processuais e conceituais da minha pesquisa artística. Calcada nas relações entre imagem e texto, esta investigação objetiva delinear as potencialidades de uma visualidade construída com a participação da escrita literária, com foco nas possibilidades de seleção, montagem e ressignificação de textos. O acercamento dos diálogos entre o espaço visual e o literário é dado a partir do reconhecimento de referências artísticas imprescindíveis para esta pesquisa, valorizando também as proposições teóricas de diversos autores. &nbsp