904 resultados para Quad-Tree decomposition
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Methods for the extraction of features from physiological datasets are growing needs as clinical investigations of Alzheimer’s disease (AD) in large and heterogeneous population increase. General tools allowing diagnostic regardless of recording sites, such as different hospitals, are essential and if combined to inexpensive non-invasive methods could critically improve mass screening of subjects with AD. In this study, we applied three state of the art multiway array decomposition (MAD) methods to extract features from electroencephalograms (EEGs) of AD patients obtained from multiple sites. In comparison to MAD, spectral-spatial average filter (SSFs) of control and AD subjects were used as well as a common blind source separation method, algorithm for multiple unknown signal extraction (AMUSE). We trained a feed-forward multilayer perceptron (MLP) to validate and optimize AD classification from two independent databases. Using a third EEG dataset, we demonstrated that features extracted from MAD outperformed features obtained from SSFs AMUSE in terms of root mean squared error (RMSE) and reaching up to 100% of accuracy in test condition. We propose that MAD maybe a useful tool to extract features for AD diagnosis offering great generalization across multi-site databases and opening doors to the discovery of new characterization of the disease.
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In this work we explore the multivariate empirical mode decomposition combined with a Neural Network classifier as technique for face recognition tasks. Images are simultaneously decomposed by means of EMD and then the distance between the modes of the image and the modes of the representative image of each class is calculated using three different distance measures. Then, a neural network is trained using 10- fold cross validation in order to derive a classifier. Preliminary results (over 98 % of classification rate) are satisfactory and will justify a deep investigation on how to apply mEMD for face recognition.
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Artifacts are present in most of the electroencephalography (EEG) recordings, making it difficult to interpret or analyze the data. In this paper a cleaning procedure based on a multivariate extension of empirical mode decomposition is used to improve the quality of the data. This is achieved by applying the cleaning method to raw EEG data. Then, a synchrony measure is applied on the raw and the clean data in order to compare the improvement of the classification rate. Two classifiers are used, linear discriminant analysis and neural networks. For both cases, the classification rate is improved about 20%.
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L’arbre, un dels símbols més universals i un element intrínsecament vinculat al desenvolupament de la nostra cultura, esdevé, en aquest llibre, el pretext idoni per donar a conèixer alguns dels interrogants que la vivència de l’art contemporani planteja. L’artista Àlex Nogué obre les portes del seu procés de creació per fer visible com es desencadena la gènesi d’una obra d’art i posa a la llum les incerteses, les intuïcions i les aspiracions que comporta la creació artística. Dibuixar un arbre tracta de les similituds entre l’emoció que produeix un plançó al mig d’un bosc i l’emoció de traslladar-lo fins a l’interior d’una presó. De les diferències de dibuixar un xiprer dret o abatut. Dels silencis i dels sorolls de les imatges. Del que una obra pretén i del que mai aconsegueix. Les imatges i els textos d’aquest llibre ens permeten transitar per l’interior de vuit processos de creació i ens mostren com els treballs artístics neixen i creixen. Per emmarcar l’experiència creativa en el context cultural contemporani, Dibuixar unarbre s’inicia amb cinc reflexions d’autors que han viscut amb empatia aquest recorregutcreatiu. Ells mateixos estan immersos de manera apassionada en la creació, producció,difusió o direcció de projectes creatius, i són: Eudald Camps, Xavier Franquesa, Rosa Pera, Víctor Sunyol i Àngels Viladomiu.
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This plan was developed to assist Alburnett with the management, budgeting and future planning of their urban forest. Across the state, forestry budgets continue to decrease with more and more of that money spent on tree removal. With the anticipated arrival of Emerald Ash Borer (EAB), an invasive pest that kills native ash trees, it is time to prepare for the increased costs of tree removal and replacement planting. With proper planning and management of the current canopy in Alburnett, these costs can be extended over years and public safety issues from dead and dying ash trees mitigated. Trees are an important component of Alburnett’s infrastructure and one of the greatest assets to the community. The benefits of trees are immense. Trees provide the community with improved air quality, stormwater runoff interception, energy conservation, lower traffic speeds, increased property values, reduced crime, improved mental health and create a desirable place to live, to name just a few benefits. It is essential that these benefits be maintained for the people of Alburnett and future generations through good urban forestry management. Good urban forestry management involves setting goals and developing management strategies to achieve these goals. An essential part of developing management strategies is a comprehensive public tree inventory. The inventory supplies information that will be used for maintenance, removal schedules, tree planting and budgeting. Basing actions on this information will help meet Alburnett’s urban forestry goals.
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This plan was developed to assist Avoca with the management, budgeting and future planning of their urban forest. Across the state, forestry budgets continue to decrease with more and more of that money spent on tree removal. With the anticipated arrival of Emerald Ash Borer (EAB), an invasive pest that kills native ash trees, it is time to prepare for the increased costs of tree removal and replacement planting. With proper planning and management of the current canopy in Avoca, these costs can be extended over years and public safety issues from dead and dying ash trees mitigated. Trees are an important component of Avoca’s infrastructure and one of the greatest assets to the community. The benefits of trees are immense. Trees provide the community with improved air quality, stormwater runoff interception, energy conservation, lower traffic speeds, increased property values, reduced crime, improved mental health and create a desirable place to live, to name just a few benefits. It is essential that these benefits be maintained for the people of Avoca and future generations through good urban forestry management. Good urban forestry management involves setting goals and developing management strategies to achieve these goals. An essential part of developing management strategies is a comprehensive public tree inventory. The inventory supplies information that will be used for maintenance, removal schedules, tree planting and budgeting. Basing actions on this information will help meet Avoca’s urban forestry goals.
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This plan was developed to assist Belle Plaine with the management, budgeting and future planning of their urban forest. Across the state, forestry budgets continue to decrease with more and more of that money spent on tree removal. With the anticipated arrival of Emerald Ash Borer (EAB), an invasive pest that kills native ash trees, it is time to prepare for the increased costs of tree removal and replacement planting. With proper planning and management of the current canopy in Belle Plaine, these costs can be extended over years and public safety issues from dead and dying ash trees mitigated. Trees are an important component of Belle Plaine’s infrastructure and one of the greatest assets to the community. The benefits of trees are immense. Trees provide the community with improved air quality, stormwater runoff interception, energy conservation, lower traffic speeds, increased property values, reduced crime, improved mental health and create a desirable place to live, to name just a few benefits. It is essential that these benefits be maintained for the people of Belle Plaine and future generations through good urban forestry management. Good urban forestry management involves setting goals and developing management strategies to achieve these goals. An essential part of developing management strategies is a comprehensive public tree inventory. The inventory supplies information that will be used for maintenance, removal schedules, tree planting and budgeting. Basing actions on this information will help meet Belle Plaine’s urban forestry goals.
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The objective of this study was to evaluate the mycorrhizal dependency of mangaba tree (Hancornia speciosa) plantlets, under increasing levels of phosphorus fertilization. The experimental design was completely randomized in a 4×5 factorial arrangement with three mycorrhizal fungi inocula - Gigaspora margarita, Glomus etunicatum, or a pool of native mycorrhizal fungi (Acaulospora longula, Glomus clarum, Gigaspora albida, Paraglomus sp.) -, and a nonmycorrhizal control, in combination with five levels of phosphorus applied to the substrate: 0, 25, 50, 75, and 100 mg kg-1. After 180 days of growth, plantlets with inoculation of native mycorrhizal pool produced more shoot and root dry biomass and had higher shoot phosphorus content and accumulation. The noninoculated control showed the lowest values, independently of the phosphorus level. The highest relative mycorrhizal dependency occurred with the inoculation of native mycorrhizal fungi. Plants with mycorrhizal fungi did not respond to phosphorus addition above 50 mg kg-1. Mangaba tree is highly dependent on mycorrhiza, but the degree of dependency varies according to phosphorus levels and fungal inocula. In general, mangaba tree is more responsive to mycorrhizal fungi inoculation than to phosphorus addition.
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Experimental research has identified many putative agents of amphibian decline, yet the population-level consequences of these agents remain unknown, owing to lack of information on compensatory density dependence in natural populations. Here, we investigate the relative importance of intrinsic (density-dependent) and extrinsic (climatic) factors impacting the dynamics of a tree frog (Hyla arborea) population over 22 years. A combination of log-linear density dependence and rainfall (with a 2-year time lag corresponding to development time) explain 75% of the variance in the rate of increase. Such fluctuations around a variable return point might be responsible for the seemingly erratic demography and disequilibrium dynamics of many amphibian populations.
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Ecosystems are complex systems and changing one of their components can alter their whole functioning. Decomposition and biodiversity are two factors that play a role in this stability, and it is vital to study how these two factors are interrelated and how other factors, whether of human origin or not, can affect them. This study has tested different hypotheses regarding the effects of pesticides and invasive species on the biodiversity of the soil fauna and litter decomposition rate. Decomposition was measured using the litterbags technique. Our results indicate that pesticides had a negative effect on decomposition whereas invasive species increased decomposition rate. At the same time, the diversity of the soil biota was unaffected by either factor. These results allow us to better understand the response of important ecosystem functions to human‐induced alterations, in order to mitigate harmful effects or restore them wherever necessary.
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