Modelo de Aprendizado Incremental Baseado em Uma Rede Neural com Arquitetura Adaptativa

Este trabalho apresenta uma abordagem baseada em Redes Neurais Artificiais para problemas de classificação multi-rotulada. Em particular, foi empregada uma versão modificada da Rede Neural Probabilística para tratar de tais problemas. Em experimentos realizados em várias bases de dados conhecidas na literatura, a Rede Neural Probabilística proposta apresentou um desempenho comparável, e algumas vezes até superior, a outros algoritmos especializados neste tipo de problema. Como o foco principal deste trabalho foi o estudo de estratégias para classificação automática de texto de atividades econômicas, foram realizados também experimentos utilizando uma base de dados de atividades econômicas. No entanto, diferente das bases de dados utilizadas anteriormente, esta base de dados apresenta um número extenso de categorias e poucas amostras de treino por categoria, o que aumenta o grau de dificuldade deste problema. Nos experimentos realizados foram utilizados a Rede Neural Probabilística proposta, o classificador k-Vizinhos mais Próximos Multi-rotulado, e um Algoritmo Genético para otimização dos parâmetros dos mesmos. Nas métricas utilizadas para avaliação de desempenho, a Rede Neural Probabilística mostrou resultados superiores e comparáveis aos resultados obtidos pelo k-Vizinhos mais Próximos Multi-rotulado, mostrando que a abordagem utilizada neste trabalho é promissora

Rede Neural Probabilística para a Classificação de Atividades Econômicas

Este trabalho apresenta uma abordagem baseada em Redes Neurais Artificiais para problemas de classificação multi-rotulada. Em particular, foi empregada uma versão modificada da Rede Neural Probabilística para tratar de tais problemas. Em experimentos realizados em várias bases de dados conhecidas na literatura, a Rede Neural Probabilística proposta apresentou um desempenho comparável, e algumas vezes até superior, a outros algoritmos especializados neste tipo de problema. Como o foco principal deste trabalho foi o estudo de estratégias para classificação automática de texto de atividades econômicas, foram realizados também experimentos utilizando uma base de dados de atividades econômicas. No entanto, diferente das bases de dados utilizadas anteriormente, esta base de dados apresenta um número extenso de categorias e poucas amostras de treino por categoria, o que aumenta o grau de dificuldade deste problema. Nos experimentos realizados foram utilizados a Rede Neural Probabilística proposta, o classificador k-Vizinhos mais Próximos Multi-rotulado, e um Algoritmo Genético para otimização dos parâmetros dos mesmos. Nas métricas utilizadas para avaliação de desempenho, a Rede Neural Probabilística mostrou resultados superiores e comparáveis aos resultados obtidos pelo k-Vizinhos mais Próximos Multi-rotulado, mostrando que a abordagem utilizada neste trabalho é promissora

Modelling winter organic aerosol at the European scale with CAMx : evaluation and source apportionment with a VBS parameterization based on novel wood burning smog chamber experiments

We evaluated a modified VBS (volatility basis set) scheme to treat biomass-burning-like organic aerosol (BBOA) implemented in CAMx (Comprehensive Air Quality Model with extensions). The updated scheme was parameterized with novel wood combustion smog chamber experiments using a hybrid VBS framework which accounts for a mixture of wood burning organic aerosol precursors and their further functionalization and fragmentation in the atmosphere. The new scheme was evaluated for one of the winter EMEP intensive campaigns (February March 2009) against aerosol mass spectrometer (AMS) measurements performed at 11 sites in Europe. We found a considerable improvement for the modelled organic aerosol (OA) mass compared to our previous model application with the mean fractional bias (MFB) reduced from 61 to 29 %. We performed model-based source apportionment studies and compared results against positive matrix factorization (PMF) analysis performed on OA AMS data. Both model and observations suggest that OA was mainly of secondary origin at almost all sites. Modelled secondary organic aerosol (SOA) contributions to total OA varied from 32 to 88 % (with an average contribution of 62 %) and absolute concentrations were generally under-predicted. Modelled primary hydrocarbon-like organic aerosol (HOA) and primary biomass-burning-like aerosol (BBPOA) fractions contributed to a lesser extent (HOA from 3 to 30 %, and BBPOA from 1 to 39 %) with average contributions of 13 and 25 %, respectively. Modelled BBPOA fractions were found to represent 12 to 64 % of the total residential-heating-related OA, with increasing contributions at stations located in the northern part of the domain. Source apportionment studies were performed to assess the contribution of residential and non-residential combustion precursors to the total SOA. Non-residential combustion and road transportation sector contributed about 30-40 % to SOA formation (with increasing contributions at urban and near industrialized sites), whereas residential combustion (mainly related to wood burning) contributed to a larger extent, around 60-70 %. Contributions to OA from residential combustion precursors in different volatility ranges were also assessed: our results indicate that residential combustion gas-phase precursors in the semivolatile range (SVOC) contributed from 6 to 30 %, with higher contributions predicted at stations located in the southern part of the domain On the other hand, the oxidation products of higher-volatility precursors (the sum of intermediate-volatility compounds (IVOCs) and volatile organic compounds (VOCs)) contribute from 15 to 38 % with no specific gradient among the stations. Although the new parameterization leads to a better agreement between model results and observations, it still under predicts the SOA fraction, suggesting that uncertainties in the new scheme and other sources and/or formation mechanisms remain to be elucidated. Moreover, a more detailed characterization of the semivolatile components of the emissions is needed.Peer reviewe

Foot Bone in Vivo: Its Center of Mass and Centroid of Shape

This paper studies foot bone geometrical shape and its mass distribution and establishes an assessment method of bone strength. Using spiral CT scanning, with an accuracy of sub-millimeter, we analyze the data of 384 pieces of foot bones in vivo and investigate the relationship between the bone's external shape and internal structure. This analysis is explored on the bases of the bone's center of mass and its centroid of shape. We observe the phenomenon of superposition of center of mass and centroid of shape fairly precisely, indicating a possible appearance of biomechanical organism. We investigate two aspects of the geometrical shape, (i) distance between compact bone's centroid of shape and that of the bone and (ii) the mean radius of the same density bone issue relative to the bone's centroid of shape. These quantities are used to interpret the influence of different physical exercises imposed on bone strength, thereby contributing to an alternate assessment technique to bone strength.Comment: 9 pages, 4 figure

Comportamento de cafeeiros (Coffea arabica L. cv. mundo novo) oriundos de ecossistemas diversos, sob condições uniformes

It was studied the behavior of coffee plants (Coffea arabica L. cv. Mundo Novo) originated from different environment conditions (shade, half shaded, unshaded and greenhouse) when submited to field conditions. It was realized evaluations on morphology, development, and biological productivity of coffee plants. It was verified nutrient levels, attack of insects and unfavourable effects of sun radiation on leaves. Plants originated from greenhouse and half shaded conditions showed higher growth. Higher number of branches were observed in plants from clarity conditions, and plants from more shaded conditions showed higher number of leaves by branch. Plants originated from shaded conditions showed a tendency of recuperation in field conditions. Coffee plants from half shaded conditions presented higher leaf dry weight tham plants originated from greenhouse. Both presented good adaptation in field conditions after 75 days. Stems and roots dry weith where heigher in coffee plants originated from greenhouse conditions. It was determined higher N levels in leaves of plants from unshaded conditions, and higher P and Ca levels in plants from half shaded conditions. Half shaded conditions promoted accumulation of Zn In coffee plants. Stems presented nutrient levels higher tham leaves, except for Zn and Cu. Plants originated from unshaded conditions showed higher Ca and S levels. Roots presented nutrient levels higher tham leaves except for Cu, Zn, and Mn. Data of infestation of leaves with Perileucoptera coffeella have pointed out a higher incidence in greenhouse conditions, cof fee plants in more shaded conditions showed lower incidence of the insect. Infestation of Coccus viridis presented higher incidence on plants originated from half shaded conditions. Coffee plants from unshaded and greenhouse conditions did not present sunburn spots on leaves, however plants from half shaded and shaded conditions where considerably danified. Shade affected the growth of coffee plants in function of its intensity and interaction with other biotics and abiotics factors of ecossistem.Estudou-se o desempenho de cafeeiros (Coffea arabica L. cv. Mundo Novo) originários de quatro ecossistemas diferentes (sombra, meia sombra, pleno sol e casa de vegetação), quando submetidos a condições de campo. Realizaram-se avaliações da morfologia, desenvolvimento e produtividade biológica do cafeeiro. Efetuaram-se também determinações da nutrição mineral, infestação de pragas e solarização. O crescimento em altura revelou-se superior nas plantas originárias de casa de vegetação e meia sombra. O número de ramos mostrou-se mais elevado em cafeeiros provenientes de locais mais ensolarados, sendo que plantas originárias de locais mais sombreados apresentaram maior número de folhas por ramo. Nestes três parâmetros notou-se uma tendência de recuperação nas condições de campo em cafeeiros provenientes de sombra. O peso da matéria seca foliar revelou-se mais elevado em plantas oriundas de meia sombra e mais baixo naquelas provenientes de casa de vegetação, sendo que nos dois ocorreu adaptação às condições de campo num período de 75 dias. O peso da matéria seca do caule e das raízes mostrou-se mais alto nos cafeeiros originários de casa de vegetação, sendo que a melhor adaptação às condições uniformes também ocorreu com as plantas oriundas da sombra. Quanto ao aspecto nutricional, determinaram-se teores mais elevados de N foliar em plantas oriundas de pleno sol e níveis mais altos de P e Ca em cafeeiros originários de meia sombra. Esse tratamento promoveu também acúmulo de Zn no cafeeiro. O caule dos cafeeiros mostrou teores de nutrientes inferiores às folhas, exceto o nível mais alto de Zn e os níveis semelhantes de Cu. Plantas originárias de pleno sol apresentaram teores mais elevados de Ca e S. As raízes mostraram níveis de nutrientes superiores ao caule e inferiores às folhas, exceto no caso do Cu, Zn e Mn, que se revelaram mais altos no sistema radicular. O nível de infestação de Perileucoptera coffeclla mostrou-se mais elevado nas plantas provenientes de casa de vegetação, sendo que cafeeiros originários de locais sombreados revelaram-se pouco afetados. A infestação de Coccus viridis revelou-se sempre mais elevada em plantas provenientes de meia sombra. Cafeeiros oriundos de pleno sol e ca sa de vegetação não sofreram solarização, sendo que aqueles provenientes de meia sombra e sombra sofreram danos crescentes nas folhas. Sombreamento afetou o desenvolvimento dos cafeeiros em função de sua intensidade e interação com outros fatores bióticos e abióticos do ecossistema

Factors affecting space use by laying hens in a cage-free aviary system: effect of nest lighting at pullet housing and of curtain nest color during laying

At 17 wk of age, 1,800 Lohman brown hens were housed in 8 pens of an experimental aviary system, specifically set up for the purposes of the present study, and kept until 26 wk without or with nest lighting (lights inside the nest 1.5 h before the lighting of the installation) for training in the nest use. Then, at 27 wk, 4 combinations of nest curtains were adopted to evaluate the effects on hens’ distribution, that is, nests with red (RR) or yellow (YY) curtains at all tiers; nests with red and yellow curtains at the first and second tier, respectively (RY); or nests with yellow and red curtains at the first and second tier, respectively (YR). The use of enlightened compared to dark nests at housing increased the oviposition rate (P < 0.001) and decreased the rate of broken (P < 0.001) and dirty eggs (P < 0.05) from 27 to 45 wk, while increasing the rate of eggs laid inside the nests (P < 0.001). The presence of yellow nest curtains increased the rate of hens on the floor in pens YY and YR compared to pens RR and RY (35.3 and 35.5% vs. 34.1 and 33.3%, respectively; P = 0.05) and the rate of floor eggs in pens YR (2.23% vs. 1.63 and 1.65% in pens RR and RY; P < 0.05). In pens RY, a higher rate of eggs was always found on the second tier compared to the first one with the most inhomogeneous distribution compared to pens RR, YY, and YR (+10.8 vs. +3.4, +1.9, and +4.6 percentage points of eggs laid on the second tier compared to the first one, respectively). In conclusion, nest lighting at housing trained hens to the use of nests while improving egg production in terms of quantity and quality. The use of yellow curtains on nests moved hens between the different levels of the aviary but this was not associated with an increased nest use for laying

Effects of two different biogenic emission models on modelled ozone and aerosol concentrations in Europe

Biogenic volatile organic compound (BVOC) emissions are one of the essential inputs for chemical transport models (CTMs), but their estimates are associated with large uncertainties, leading to significant influence on air quality modelling. This study aims to investigate the effects of using different BVOC emission models on the performance of a CTM in simulating secondary pollutants, i.e. ozone, organic, and inorganic aerosols. European air quality was simulated for the year 2011 by the regional air quality model Comprehensive Air Quality Model with Extensions (CAMx) version 6.3, using BVOC emissions calculated by two emission models: the Paul Scherrer Institute (PSI) model and the Model of Emissions of Gases and Aerosol from Nature (MEGAN) version 2.1. Comparison of isoprene and monoterpene emissions from both models showed large differences in their general amounts, as well as their spatial distribution in both summer and winter. MEGAN produced more isoprene emissions by a factor of 3 while the PSI model generated 3 times the monoterpene emissions in summer, while there was negligible difference (∼4&thinsp;%) in sesquiterpene emissions associated with the two models. Despite the large differences in isoprene emissions (i.e. 3-fold), the resulting impact in predicted summertime ozone proved to be minor (&lt;10&thinsp;%; MEGAN O3 was higher than PSI O3 by ∼7&thinsp;ppb). Comparisons with measurements from the European air quality database (AirBase) indicated that PSI emissions might improve the model performance at low ozone concentrations but worsen performance at high ozone levels (&gt;60&thinsp;ppb). A much larger effect of the different BVOC emissions was found for the secondary organic aerosol (SOA) concentrations. The higher monoterpene emissions (a factor of ∼3) by the PSI model led to higher SOA by ∼110&thinsp;% on average in summer, compared to MEGAN, and lead to better agreement between modelled and measured organic aerosol (OA): the mean bias between modelled and measured OA at nine measurement stations using Aerodyne aerosol chemical speciation monitors (ACSMs) or Aerodyne aerosol mass spectrometers (AMSs) was reduced by 21&thinsp;%–83&thinsp;% at rural or remote stations. Effects on inorganic aerosols (particulate nitrate, sulfate, and ammonia) were relatively small (&lt;15&thinsp;%).</p

Solar “brightening” impact on summer surface ozone between 1990 and 2010 in Europe – a model sensitivity study of the influence of the aerosol–radiation interactions

Surface solar radiation (SSR) observations have indicated an increasing trend in Europe since the mid-1980s, referred to as solar brightening. In this study, we used the regional air quality model, CAMx (Comprehensive Air Quality Model with Extensions) to simulate and quantify, with various sensitivity runs (where the year 2010 served as the base case), the effects of increased radiation between 1990 and 2010 on photolysis rates (with the PHOT1, PHOT2 and PHOT3 scenarios, which represented the radiation in 1990) and biogenic volatile organic compound (BVOC) emissions (with the BIO scenario, which represented the biogenic emissions in 1990), and their consequent impacts on summer surface ozone concentrations over Europe between 1990 and 2010. The PHOT1 and PHOT2 scenarios examined the effect of doubling and tripling the anthropogenic PM2.5 concentrations, respectively, while the PHOT3 investigated the impact of an increase in just the sulfate concentrations by a factor of 3.4 (as in 1990), applied only to the calculation of photolysis rates. In the BIO scenario, we reduced the 2010 SSR by 3 % (keeping plant cover and temperature the same), recalculated the biogenic emissions and repeated the base case simulations with the new biogenic emissions. The impact on photolysis rates for all three scenarios was an increase (in 2010 compared to 1990) of 3–6 % which resulted in daytime (10:00–18:00 Local Mean Time – LMT) mean surface ozone differences of 0.2–0.7 ppb (0.5–1.5 %), with the largest hourly difference rising as high as 4–8 ppb (10–16 %). The effect of changes in BVOC emissions on daytime mean surface ozone was much smaller (up to 0.08 ppb,  ∼  0.2 %), as isoprene and terpene (monoterpene and sesquiterpene) emissions increased only by 2.5–3 and 0.7 %, respectively. Overall, the impact of the SSR changes on surface ozone was greater via the effects on photolysis rates compared to the effects on BVOC emissions, and the sensitivity test of their combined impact (the combination of PHOT3 and BIO is denoted as the COMBO scenario) showed nearly additive effects. In addition, all the sensitivity runs were repeated on a second base case with increased NOx emissions to account for any potential underestimation of modeled ozone production; the results did not change significantly in magnitude, but the spatial coverage of the effects was profoundly extended. Finally, the role of the aerosol–radiation interaction (ARI) changes in the European summer surface ozone trends was suggested to be more important when comparing to the order of magnitude of the ozone trends instead of the total ozone concentrations, indicating a potential partial damping of the effects of ozone precursor emissions' reduction.</p

Evaluation of European air quality modelled by CAMx including the volatility basis set scheme

Four periods of EMEP (European Monitoring and Evaluation Programme) intensive measurement campaigns (June 2006, January 2007, September-October 2008 and February-March 2009) were modelled using the regional air quality model CAMx with VBS (volatility basis set) approach for the first time in Europe within the framework of the EURODELTA-III model intercomparison exercise. More detailed analysis and sensitivity tests were performed for the period of February-March 2009 and June 2006 to investigate the uncertainties in emissions as well as to improve the modelling of organic aerosol (OA). Model performance for selected gas phase species and PM2.5 was evaluated using the European air quality database AirBase. Sulfur dioxide (SO2) and ozone (O-3) were found to be overestimated for all the four periods, with O-3 having the largest mean bias during June 2006 and January-February 2007 periods (8.9 pbb and 12.3 ppb mean biases respectively). In contrast, nitrogen dioxide (NO2) and carbon monoxide (CO) were found to be underestimated for all the four periods. CAMx reproduced both total concentrations and monthly variations of PM2.5 for all the four periods with average biases ranging from -2.1 to 1.0 mu g m(-3). Comparisons with AMS (aerosol mass spectrometer) measurements at different sites in Europe during February-March 2009 showed that in general the model overpredicts the inorganic aerosol fraction and underpredicts the organic one, such that the good agreement for PM2.5 is partly due to compensation of errors. The effect of the choice of VBS scheme on OA was investigated as well. Two sensitivity tests with volatility distributions based on previous chamber and ambient measurements data were performed. For February-March 2009 the chamber case reduced the total OA concentrations by about 42% on average. In contrast, a test based on ambient measurement data increased OA concentrations by about 42% for the same period bringing model and observations into better agreement. Comparison with the AMS data at the rural Swiss site Payerne in June 2006 shows no significant improvement in modelled OA concentration. Further sensitivity tests with increased biogenic and anthropogenic emissions suggest that OA in Payerne was affected by changes in emissions from residential heating during the February-March 2009 whereas it was more sensitive to biogenic precursors in June 2006.Peer reviewe

On the formation of biogenic secondary organic aerosol in chemical transport models: an evaluation of the WRF-CHIMERE (v2020r2) model with a focus over the Finnish boreal forest

We present an evaluation of the regional chemical transport model (CTM) WRF-CHIMERE (v2020r2) for the formation of biogenic secondary organic aerosol (BSOA) with a focus over the Finnish boreal forest. Formation processes of biogenic aerosols are still affected by different sources of uncertainties, and model predictions vary greatly depending on the levels of details of the adopted chemical and emissions schemes. In this study, air quality simulations were conducted for the summer of 2019 using different organic aerosol (OA) schemes (as currently available in the literature) to treat the formation of BSOA. First, we performed a set of simulations in the framework of the volatility basis set (VBS) scheme carrying different assumptions for the treatment of the aging processes of BSOA. The results of the model were compared against high-resolution (i.e., 1 h) organic aerosol mass and size distribution measurements performed at the Station for Measuring Ecosystem–Atmosphere Relations (SMEAR-II) site located in Hyytiälä, in addition to other gas-phase species such as ozone (O3), nitrogen oxides (NOx), and biogenic volatile organic compound (BVOC) measurements of isoprene (C5H10) and monoterpenes. We show that WRF-CHIMERE could reproduce well the diurnal variation of the measured OA concentrations for all the investigated scenarios (along with the standard meteorological parameters) as well as the increase in concentrations during specific heat wave episodes. However, the modeled OA concentrations varied greatly between the schemes used to describe the aging processes of BSOA, as also confirmed by an additional evaluation using organic carbon (OC) measurement data retrieved from the EBAS European databases. Comparisons with isoprene and monoterpene air concentrations revealed that the model captured the observed monoterpene concentrations, but isoprene was largely overestimated, a feature that was mainly attributed to the overstated biogenic emissions of isoprene. We investigated the potential consequences of such an overestimation by inhibiting isoprene emissions from the modeling system. Results indicated that the modeled BSOA concentrations increased in the northern regions of the domain (e.g., Finland) compared to southern European countries, possibly due to a shift in the reactions of monoterpene compounds against available radicals, as further suggested by the reduction in α-pinene modeled air concentrations. Finally, we briefly analyze the differences in the modeled cloud liquid water content (clwc) among the simulations carrying different chemical schemes for the treatment of the aging processes of BSOA. The results of the model indicated an increase in clwc values at the SMEAR-II site, for simulations with higher biogenic organic aerosol loads, most likely as a result of the increased number of biogenic aerosol particles capable of activating cloud droplets.</p