Previsão do índice bovespa por meio de redes neurais artificiais: uma análise comparada aos métodos tradicionais de séries de tempo

Forecast is the basis for making strategic, tactical and operational business decisions. In financial economics, several techniques have been used to predict the behavior of assets over the past decades.Thus, there are several methods to assist in the task of time series forecasting, however, conventional modeling techniques such as statistical models and those based on theoretical mathematical models have produced unsatisfactory predictions, increasing the number of studies in more advanced methods of prediction. Among these, the Artificial Neural Networks (ANN) are a relatively new and promising method for predicting business that shows a technique that has caused much interest in the financial environment and has been used successfully in a wide variety of financial modeling systems applications, in many cases proving its superiority over the statistical models ARIMA-GARCH. In this context, this study aimed to examine whether the ANNs are a more appropriate method for predicting the behavior of Indices in Capital Markets than the traditional methods of time series analysis. For this purpose we developed an quantitative study, from financial economic indices, and developed two models of RNA-type feedfoward supervised learning, whose structures consisted of 20 data in the input layer, 90 neurons in one hidden layer and one given as the output layer (Ibovespa). These models used backpropagation, an input activation function based on the tangent sigmoid and a linear output function. Since the aim of analyzing the adherence of the Method of Artificial Neural Networks to carry out predictions of the Ibovespa, we chose to perform this analysis by comparing results between this and Time Series Predictive Model GARCH, developing a GARCH model (1.1).Once applied both methods (ANN and GARCH) we conducted the results' analysis by comparing the results of the forecast with the historical data and by studying the forecast errors by the MSE, RMSE, MAE, Standard Deviation, the Theil's U and forecasting encompassing tests. It was found that the models developed by means of ANNs had lower MSE, RMSE and MAE than the GARCH (1,1) model and Theil U test indicated that the three models have smaller errors than those of a naïve forecast. Although the ANN based on returns have lower precision indicator values than those of ANN based on prices, the forecast encompassing test rejected the hypothesis that this model is better than that, indicating that the ANN models have a similar level of accuracy . It was concluded that for the data series studied the ANN models show a more appropriate Ibovespa forecasting than the traditional models of time series, represented by the GARCH model

Comunidades tradicionais em áreas protegidas: convergências e lacunas da Política Urbana e Ambiental na Reserva de Desenvolvimento Sustentável Estadual Ponta do Tubarão/RN

This work presents a reflection on possibilities and boundaries of consolidation and expansion of human settlements characterized as traditional communities that are located within protected areas, using as study reference the State Sustainable Development Reserve Ponta do Tubarão, at Rio Grande do Norte state. The main topics highlight the conflict between the right to housing and the prevalence of fundamental rights of traditional populations, opposed to the diffuse right to environment, according to the regulatory framework of the Brazilian Urban and Environmental Policies. At the same time that these settlements, historically built, are substantiated by the principles of recognition of rights to traditional populations, they are in a condition of complexity to the resolution of conflicts in its urban dimension and lead to an impairment of natural sites. This work questions how the instruments of land use and occupation are defined and relate to environmental planning, especially considering that the settlements are located in Permanent Preservation Areas (APP). It aims to further the discussion of the urban dimension in settlements, characterizing its formation and growth process, to identify the gaps and convergences between the Urban and Environmental Policy, under the foundations of a socio-environmental approach. The results spotlights the conflicts between occupation and natural areas, inferring that the definition of Urban Policies instruments and its integration with Environmental Policies instruments account for essential and priority actions to the achievement to the rights to a sustainable city, as determined in the Cities Statute and environmental protection goals, defined for the Conservation Units

Mercado de trabalho, ocupações e rendimentos: a Região Metropolitana de Natal na década de 1990

The aim of this study is the labour market at Natal Metropolitan Region with emphasis in occupations and incomes that took place at the nineties. The definition of its chronological boundaries passed by verification of existence of evident socio-spatial impacts for output, occupation and income in national economy, with rebounds in all national territory, conditioned by institutional and socio-economical transformations which marked Brazilian insertion to capital flows and commodities globalization movement that took place at the cited decade. It has been shown that such impacts did not distributed themselves equally between diverse spatial levels (great regions, federate unities, municipalities) because of historical specificities in each place in terms of output structures and organization of distinct social agents. Having as its basis the Marxist perspective, it tackled theoretically occupations and incomes, transformations in labour universe occurred at world level, mainly in most urbanized areas, and following that to focus changes occurred in Brazilian society related to the search for competitive insertion in global economy during the period regarded. Special attention was gave to Natal Metropolitan Region, because it was historically a concentration area for investments, productive structure, people, occupations and incomes generated/appropriated in Rio Grande do Norte State. The basic data sources for research were the demographic Census (micro data) made by the Instituto Brasileiro de Geografia e Estatística (IBGE) intending to present the structure and the labour market dynamics, having as basis: 1) traditional indicators about labour market; 2) sectors of economic activities and 3) social positions and classes segments. One of the purposes is the demonstration that occupations and incomes keep relation with the restructuring which occurred in each specific sector during the period. Other purpose is to make explicit the factors which bear the participation of distinct segments in production or service execution that make possible the different participation in income distribution. Results are revealing the increasin precariousness in labour market, enlargement of occupations in tertiary sector and greater concentration of average incomes in the social segments which were owners of the greatest capital allowances between residents in Natal Metropolitan Region during the nineties

Geometria e simetria nas rendas de bilro: contribuições para matemática escolar

A tese tem como objetivo descrever e analisar características e princípios dos padrões das rendas de bilro de modo a estabelecer relações com a Matemática escolar, principalmente, no que se refere aos tópicos como Geometria, simetria, isometria, área, perímetro, entre outros. Desse modo, elaboramos atividades didáticas, com base na Matemática explorada nos padrões da criação da renda de bilro, visando concretizar um exercício investigatório nas aulas de Matemática, de modo que, sejam estabelecidas relações conceituais entre a prática investigada e os conteúdos da Matemática escolar. Para satisfazer esses objetivos, buscamos apoio metodológico na pesquisa bibliográfica, do tipo documental em catálogos como o da Professora Valdelice Girão (1984) e também o de Dawson (1984). Realizamos também a pesquisa empírica durante as visitas ao Museu do Ceará e ao Centro das Rendeiras na Prainha, em Aquiraz, no Ceará. Para realizar as atividades didáticas, apoiamo-nos em Mendes (2009). Consideramos relevante essa abordagem de ensino porque pressupõe a experiência direta do aprendiz com situações reais vivenciadas, nas quais a abordagem instrucional é centrada no aluno. Desse modo, concluímos que para o ensino de conteúdos como Geometria, simetria, isometria, relação entre perímetro e área, entre outros que são abordados na Educação Básica, os modelos decorrentes da criação renda de bilro e outros modelos já descritos na tradição cearense podem ser usados como artefato cultural na criação de atividades didáticas

Etnobotânica e percepção ambiental de pescadores e coletoras tradicionais submetidos à escassez de recursos vegetais silvestres

In our first chapter was recorded the perception of fishermen and gatherers of Patané about the absence of local forests, was collected a list of species considered locally as strategic use, the ethnoknowledge associated with those, and identify which of these plants are already perceived as scarce in the region. In the second chapter, was studied all species of plants known by the community, the associated knowledge and the various uses. Were used individual interviews, formal and semi-structured, that have been consecutively applied to sampled respondents not probabilistically by snowball. Were collected socioeconomic data of informants. A adequacy test was performed. Guided tours were conducted to gather photographs and samples witnesses of plants, all identified by the usual methods of botany. Excerpts of the interviews on perceptions appear by looking for consensual information. Some data were presented by descriptive statistics. Were mounted two lists of plants, one with the strategic use and one with all the species listed in the study. It was shown that knowledge about plants remains resilient despite the forest resources now no longer be available.

Etnobotânica e percepção ambiental de pescadores e coletoras tradicionais submetidos à escassez de recursos vegetais silvestres

In our first chapter was recorded the perception of fishermen and gatherers of Patané about the absence of local forests, was collected a list of species considered locally as strategic use, the ethnoknowledge associated with those, and identify which of these plants are already perceived as scarce in the region. In the second chapter, was studied all species of plants known by the community, the associated knowledge and the various uses. Were used individual interviews, formal and semi-structured, that have been consecutively applied to sampled respondents not probabilistically by snowball. Were collected socioeconomic data of informants. A adequacy test was performed. Guided tours were conducted to gather photographs and samples witnesses of plants, all identified by the usual methods of botany. Excerpts of the interviews on perceptions appear by looking for consensual information. Some data were presented by descriptive statistics. Were mounted two lists of plants, one with the strategic use and one with all the species listed in the study. It was shown that knowledge about plants remains resilient despite the forest resources now no longer be available.

Eficiência mastigatória e qualidade das próteses totais confeccionadas pelas técnicas tradicionais e simplificada: um ensaio clínico

Traditional methods for dentures fabrication require a wide clinical and laboratory procedures; however, there is no scientific evidence that these methods can produce better results when compared with simplified methods. Aim: To evaluate the effectiveness of a simplified methods for denture fabrication, comparing it to the traditional one through masticatory efficiency and prosthesis quality. Method: A randomized controlled trial was conducted with 50 patients, 25 rehabilitated with prosthesis produced by traditional technique and 25 rehabilitated by a simplified technique. The masticatory efficiency was evaluated by colorimetric method, using chewing capsules. The quality of prosthesis was obtained using a reliable and reproducible instrument. Statistical analysis of the masticatory efficiency and quality of the prosthesis was obtained by the Mann-Whitney test. Results: 39 patients completed the study, 18 on traditional group and 21 on simplified group. There was no difference between groups for the masticatory efficiency (p = 0.835) and the quality of the prosthesis (p = 0672). The evaluation of the overall quality of the prosthesis according to oral conditions, demonstrated significant difference on the height of the mandibular ridges (p = 0.010) and mandibular muscle attachments (p = 0.039). Conclusion: Complete dentures fabricated by simplified method were considered effective from the point of view of masticatory efficiency and quality of prosthetics, with results similar to those made by the traditional method.

Eficiência mastigatória e qualidade das próteses totais confeccionadas pelas técnicas tradicionais e simplificada: um ensaio clínico

Traditional methods for dentures fabrication require a wide clinical and laboratory procedures; however, there is no scientific evidence that these methods can produce better results when compared with simplified methods. Aim: To evaluate the effectiveness of a simplified methods for denture fabrication, comparing it to the traditional one through masticatory efficiency and prosthesis quality. Method: A randomized controlled trial was conducted with 50 patients, 25 rehabilitated with prosthesis produced by traditional technique and 25 rehabilitated by a simplified technique. The masticatory efficiency was evaluated by colorimetric method, using chewing capsules. The quality of prosthesis was obtained using a reliable and reproducible instrument. Statistical analysis of the masticatory efficiency and quality of the prosthesis was obtained by the Mann-Whitney test. Results: 39 patients completed the study, 18 on traditional group and 21 on simplified group. There was no difference between groups for the masticatory efficiency (p = 0.835) and the quality of the prosthesis (p = 0672). The evaluation of the overall quality of the prosthesis according to oral conditions, demonstrated significant difference on the height of the mandibular ridges (p = 0.010) and mandibular muscle attachments (p = 0.039). Conclusion: Complete dentures fabricated by simplified method were considered effective from the point of view of masticatory efficiency and quality of prosthetics, with results similar to those made by the traditional method.

Previsão do índice bovespa por meio de redes neurais artificiais: uma análise comparada aos métodos tradicionais de séries de tempo

Forecast is the basis for making strategic, tactical and operational business decisions. In financial economics, several techniques have been used to predict the behavior of assets over the past decades.Thus, there are several methods to assist in the task of time series forecasting, however, conventional modeling techniques such as statistical models and those based on theoretical mathematical models have produced unsatisfactory predictions, increasing the number of studies in more advanced methods of prediction. Among these, the Artificial Neural Networks (ANN) are a relatively new and promising method for predicting business that shows a technique that has caused much interest in the financial environment and has been used successfully in a wide variety of financial modeling systems applications, in many cases proving its superiority over the statistical models ARIMA-GARCH. In this context, this study aimed to examine whether the ANNs are a more appropriate method for predicting the behavior of Indices in Capital Markets than the traditional methods of time series analysis. For this purpose we developed an quantitative study, from financial economic indices, and developed two models of RNA-type feedfoward supervised learning, whose structures consisted of 20 data in the input layer, 90 neurons in one hidden layer and one given as the output layer (Ibovespa). These models used backpropagation, an input activation function based on the tangent sigmoid and a linear output function. Since the aim of analyzing the adherence of the Method of Artificial Neural Networks to carry out predictions of the Ibovespa, we chose to perform this analysis by comparing results between this and Time Series Predictive Model GARCH, developing a GARCH model (1.1).Once applied both methods (ANN and GARCH) we conducted the results' analysis by comparing the results of the forecast with the historical data and by studying the forecast errors by the MSE, RMSE, MAE, Standard Deviation, the Theil's U and forecasting encompassing tests. It was found that the models developed by means of ANNs had lower MSE, RMSE and MAE than the GARCH (1,1) model and Theil U test indicated that the three models have smaller errors than those of a naïve forecast. Although the ANN based on returns have lower precision indicator values than those of ANN based on prices, the forecast encompassing test rejected the hypothesis that this model is better than that, indicating that the ANN models have a similar level of accuracy . It was concluded that for the data series studied the ANN models show a more appropriate Ibovespa forecasting than the traditional models of time series, represented by the GARCH model

Comunidades tradicionais em áreas protegidas: convergências e lacunas da Política Urbana e Ambiental na Reserva de Desenvolvimento Sustentável Estadual Ponta do Tubarão/RN

This work presents a reflection on possibilities and boundaries of consolidation and expansion of human settlements characterized as traditional communities that are located within protected areas, using as study reference the State Sustainable Development Reserve Ponta do Tubarão, at Rio Grande do Norte state. The main topics highlight the conflict between the right to housing and the prevalence of fundamental rights of traditional populations, opposed to the diffuse right to environment, according to the regulatory framework of the Brazilian Urban and Environmental Policies. At the same time that these settlements, historically built, are substantiated by the principles of recognition of rights to traditional populations, they are in a condition of complexity to the resolution of conflicts in its urban dimension and lead to an impairment of natural sites. This work questions how the instruments of land use and occupation are defined and relate to environmental planning, especially considering that the settlements are located in Permanent Preservation Areas (APP). It aims to further the discussion of the urban dimension in settlements, characterizing its formation and growth process, to identify the gaps and convergences between the Urban and Environmental Policy, under the foundations of a socio-environmental approach. The results spotlights the conflicts between occupation and natural areas, inferring that the definition of Urban Policies instruments and its integration with Environmental Policies instruments account for essential and priority actions to the achievement to the rights to a sustainable city, as determined in the Cities Statute and environmental protection goals, defined for the Conservation Units