33 research outputs found

    Controle estatístico de processo na silvicultura : teoria e aplicação

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    Orientador: Márcio Pereira da RochaMonografia (especialização) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Departamento de Economia Rural e Extensão, Curso de Pós-Graduação em Gestão FlorestalResumo: Este estudo teve como objetivo aplicar a metodologia proposta por Wheeler aos dados silviculturais da Companhia do Vale do Araguaia (Araguaia), que iniciou seus plantios de teca na região de Água Boa, Mato Grosso em 2006. A imagem do banco de dados sob análise é composta por 2.151 registros, contemplando 13 atividades realizadas nos projetos 2006/2007, 2007/2008, 2008/2009, 2009/201 O e 2010/2011, até 08 de julho de 201 O. Os rendimentos de cada atividade foram avaliados através de gráficos de controle do tipo XmR. Grande parte das atividades avaliadas apresentou pontos fora da variação natural do processo ou critérios como tendência, sequência e periodicidade. Estas evidências de falta de controle indicam que o CEP aplicado às atividades silviculturais permitem uma melhora no processo silvicultura! da empresa.Abstract: This work objective was to apply the Wheeler methodology to silvicultura! data from Companhia do Vale do Araguaia, which has started his teak plantations in Água Boa region, since 2006. The image of data base analyzed had 2.151 registers, about 13 activities, developed in 5 different projects: 2006/2007, 200712008, 2008/2009, 2009/201 O and 2010/2011, until 08th July, 2010. The activities numbers was analyzed by XmR contrai charts. Many of them have presented points or characteristics that showed behavior out of contrai. This shows opportunities to improve the silvicultura! pracess using statistical pracess contrai techniques

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Controle estatístico de processo na silvicultura : teoria e aplicação

    No full text
    Orientador: Márcio Pereira da RochaMonografia (especialização) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Departamento de Economia Rural e Extensão, Curso de Pós-Graduação em Gestão FlorestalResumo: Este estudo teve como objetivo aplicar a metodologia proposta por Wheeler aos dados silviculturais da Companhia do Vale do Araguaia (Araguaia), que iniciou seus plantios de teca na região de Água Boa, Mato Grosso em 2006. A imagem do banco de dados sob análise é composta por 2.151 registros, contemplando 13 atividades realizadas nos projetos 2006/2007, 2007/2008, 2008/2009, 2009/201 O e 2010/2011, até 08 de julho de 201 O. Os rendimentos de cada atividade foram avaliados através de gráficos de controle do tipo XmR. Grande parte das atividades avaliadas apresentou pontos fora da variação natural do processo ou critérios como tendência, sequência e periodicidade. Estas evidências de falta de controle indicam que o CEP aplicado às atividades silviculturais permitem uma melhora no processo silvicultura! da empresa.Abstract: This work objective was to apply the Wheeler methodology to silvicultura! data from Companhia do Vale do Araguaia, which has started his teak plantations in Água Boa region, since 2006. The image of data base analyzed had 2.151 registers, about 13 activities, developed in 5 different projects: 2006/2007, 200712008, 2008/2009, 2009/201 O and 2010/2011, until 08th July, 2010. The activities numbers was analyzed by XmR contrai charts. Many of them have presented points or characteristics that showed behavior out of contrai. This shows opportunities to improve the silvicultura! pracess using statistical pracess contrai techniques

    O uso de tecnologia LiDAR para quantificação e qualificação da vegetação

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    The methodology to quantify vegetation from airborne laser scanning (or LiDAR - Light Detection And Ranging) is somehow consolidated, but some concerns are still in the checklist of the scientific community. This thesis aims to bring some of those concerns and try to contribute with some results and insights. Four aspects were studied along this thesis. In the first study, the effect of threshold heights (minimum height and height break) in the quality of the set of metrics was investigated aiming the volume estimation of a eucalyptus plantation. The results indicate that higher threshold height may return a better set of metrics. The impact of threshold height was more evident in young stands and for canopy density metrics. In the second study, the stability of the LiDAR metrics between different LiDAR surveys over the same area was analyzed. This study demonstrated how the selection of stable metrics contributed to generate reliable models between different data sets. According to our results, the height metrics provided the greatest stability when used in the models, specifically the higher percentiles (>50%) and the mode. The third study was designed to evaluate the use of machine learning tools to estimate wood volume of eucalyptus plantations from LiDAR metrics. Rather than being limited to a subset of LiDAR metrics in attempting explain as much variability in a dependent variable as possible, artificial intelligence tools explored the complete metrics set when looking for patterns between LiDAR metrics and stand volume. The fourth and last study has focused upon several highly important forest typologies, and shown that it is possible to differentiate the typologies through their vertical profiles as derived from airborne laser surveys. The size of the sampling cell does have an influence on the behavior observed in analyses of spatial dependence. Each typology has its own specific characteristics, which will need to be taken into consideration in projects targeting monitoring, inventory construction, and mapping based upon airborne laser surveys. The determination of a converged vertical profile could be achieved with data representing 10 % of the area for all typologies, while for some typologies 2 % coverage was sufficient.A metodologia para quantificar vegetação a partir de dados LiDAR (Light Detection And Ranging) está de certa forma consolidada, porém ainda existem pontos a serem esclarecidos que permanecem na lista da comunidade científica. Quatro aspectos foram estudos nesta tese. No primeiro estudo, foi investigado a influência das alturas de referência (altura mínima e altura de quebra) na qualidade do conjunto de métricas extraído visando estimação do volume de um plantio de eucalipto. Os resultados indicaram que valor mais altos de alturas de referência retornaram um conjunto de métricas melhor. O efeito das alturas de referência foi mais evidente em povoamentos jovens e para as métricas de densidade. No segundo estudo, avaliou-se a estabilidade de métricas LiDAR derivadas para uma mesma área sobrevoada com diferentes configurações de equipamentos e voo. Este estudo apresentou como a seleção de métricas estáveis pode contribuir para a geração de modelos compatíveis com diferentes bases de dados LiDAR. De acordo com os resultados, as métricas de altura foram mais estáveis que as métricas de densidade, com destaque para os percentis acima de 50% e a moda. O terceiro estudo avaliou o uso de máquinas de aprendizado para a estimação do volume em nível de povoamento de plantios de eucalipto a partir de métricas LiDAR. Ao invés de estarem limitados a um pequeno subconjunto de métricas na tentativa de explicar a maior parte possível da variabilidade total dos dados, as técnicas de inteligência artificial permitiram explorar todo o conjunto de dados e detectar padrões que estimaram o volume em nível de povoamento a partir do conjunto de métricas. O quarto e último estudo focou em sete áreas de diferentes tipologias florestais brasileiras, estudando os seus perfis verticais de dossel. O estudo mostrou que é possível diferenciar estas tipologias com base no perfil vertical derivado de levantamentos LiDAR. Foi observado também que o tamanho das parcelas possui diferentes níveis de dependência espacial. Cada tipologia possui características específicas que precisam ser levadas em considerações em projetos de monitoramento, inventário e mapeamento baseado em levantamentos LiDAR. O estudo mostrou que é possível determinar o perfil vertical de dossel a partir da cobertura de 10% da área, chegando a algumas tipologias em apenas 2% da área

    Estimating tree volume using artificial neural nets

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    As redes neurais artificiais (RNAs) consistem de uma rede de unidade de processamento interligada por pesos ajustáveis. Cada unidade possui uma função matemática que processa o somatório das entradas do respectivo neurônio, gerando um valor de saída. Este valor é então repassado a todos os neurônios seguintes. Essas redes são conhecidas como redes multicamadas ântero-alimentadas. As RNAs podem ser usadas para diversas aplicações, entre elas a aproximação de funções. A estimação de volume de árvores é comumente empregada nos inventários florestais para determinar o volume de árvores, sem que elas precisem ser abatidas. Utilizando dados de cubagem de diferentes empresas florestais, foram testadas algumas formas de préprocessamento dos dados e arquiteturas de RNAs. Algumas das redes obtidas apresentaram estimativas livres de bias, podendo ser utilizadas para estimação de volume de árvores.Artificial neural networks (ANNs) consist of a processing unit network interconnected by adjustable weights. Each unit has a mathematical function that processes the sum of inputs of the respective neuron, generating an output value. This value is then passed on to all the other neurons of the next layer. Such nets are known as multi-layer feed forward neural nets. ANNs can have several applications, such as function approximation. Tree volume estimate is commonly used in forest inventories to determine tree volume without the need to fell the trees. Some ANN data pre-processing forms and architecture were tested by using tree scaling from different forest enterprises. Some of the nets obtained presented unbiased estimates, and thus can be used for estimating tree volume.Conselho Nacional de Desenvolvimento Científico e Tecnológic
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