6,071 research outputs found
Empiricism and stochastics in cellular automaton modeling of urban land use dynamics
An increasing number of models for predicting land use change in regions of rapidurbanization are being proposed and built using ideas from cellular automata (CA)theory. Calibrating such models to real situations is highly problematic and to date,serious attention has not been focused on the estimation problem. In this paper, wepropose a structure for simulating urban change based on estimating land usetransitions using elementary probabilistic methods which draw their inspiration fromBayes' theory and the related ?weights of evidence? approach. These land use changeprobabilities drive a CA model ? DINAMICA ? conceived at the Center for RemoteSensing of the Federal University of Minas Gerais (CSR-UFMG). This is based on aneight cell Moore neighborhood approach implemented through empirical land useallocation algorithms. The model framework has been applied to a medium-size townin the west of São Paulo State, Bauru. We show how various socio-economic andinfrastructural factors can be combined using the weights of evidence approach whichenables us to predict the probability of changes between land use types in differentcells of the system. Different predictions for the town during the period 1979-1988were generated, and statistical validation was then conducted using a multipleresolution fitting procedure. These modeling experiments support the essential logicof adopting Bayesian empirical methods which synthesize various information aboutspatial infrastructure as the driver of urban land use change. This indicates therelevance of the approach for generating forecasts of growth for Brazilian citiesparticularly and for world-wide cities in general
Simulation of VUV electroluminescence in micropattern gaseous detectors: the case of GEM and MHSP
Electroluminescence produced during avalanche development in gaseous
avalanche detectors is an useful information for triggering, calorimetry and
tracking in gaseous detectors. Noble gases present high electroluminescence
yields, emitting mainly in the VUV region. The photons can provide signal
readout if appropriate photosensors are used. Micropattern gaseous detectors
are good candidates for signal amplification in high background and/or low rate
experiments due to their high electroluminescence yields and radiopurity. In
this work, the VUV light responses of the Gas Electron Multiplier and of the
Micro-Hole Strip Plate, working with pure xenon, are simulated and studied in
detail using a new and versatile C++ toolkit. It is shown that the solid angle
subtended by a photosensor placed below the microstructures depends on the
operating conditions. The obtained absolute EL yields, determined for different
gas pressures and as functions of the applied voltage, are compared with those
determined experimentally.Comment: Accepted for publication in Journal of Instrumentatio
Evaluation of end-of-line treatment alternatives for electronic waste by means of material characterization of mobile phones.
Distributing multipartite entanglement over noisy quantum networks
A quantum internet aims at harnessing networked quantum technologies, namely by distributing bipartite entanglement between distant nodes. However, multipartite entanglement between the nodes may empower the quantum internet for additional or better applications for communications, sensing, and computation. In this work, we present an algorithm for generating multipartite entanglement between different nodes of a quantum network with noisy quantum repeaters and imperfect quantum memories, where the links are entangled pairs. Our algorithm is optimal for GHZ states with 3 qubits, maximising simultaneously the final state fidelity and the rate of entanglement distribution. Furthermore, we determine the conditions yielding this simultaneous optimality for GHZ states with a higher number of qubits, and for other types of multipartite entanglement. Our algorithm is general also in the sense that it can optimize simultaneously arbitrary parameters. This work opens the way to optimally generate multipartite quantum correlations over noisy quantum networks, an important resource for distributed quantum technologies.info:eu-repo/semantics/publishedVersio
Growth of different fruit tree species in silvopastoral systems during the establishment phase.
EN-US: The benefits of integrating agricultural components into silvopastoral systems are widely known, but the limited knowledge about ecological processes in the establishment phase impedes the use of this technology. The objective of this study was to evaluate interactions between fruit tree species and the sward layer under canopies of trees in the establishment phase of silvopastoral systems in Mato Grosso, Brazil. The experiment was implemented in October 2013, with an evaluation period from January to July 2015. The systems were composed of eight fruit trees intercropped with Tifton 85 grass. A completely randomized block design was adopted, with two replications per area per treatment. We evaluated the agronomic performance of the fruit trees, the categories of the light environment, and the plant accumulation under the canopies. The acerola fruit trees of the variety Roxinha had higher Leaf area index (LAI) and Light interception (LI) values, showing a denser canopy with small porosity and the lowest light quality available to the plants beneath the canopy (lower red/far-red ratio), thereby decreasing plant accumulation under trees. The guava fruit trees showed higher growth rates than the other fruit trees, but lower LAI and LI values and a higher red/far-red ratio, allowing higher plant growth under the canopy. Cajá trees showed a similar behavior; however, this species is deciduous, which limits its potential use in integrated systems. Banana and coconut trees were highly dependent on irrigation during the dry season. The remaining species showed an adequate growth and potential to control plant species growth under their canopies. | PT-BR: Os benefícios de integrar os componentes agrícolas já são bastante conhecidos, porém o conhecimento sobre os processos ecológicos da competição das plantas ainda é uma barreira para essa tecnologia. O objetivo deste estudo foi avaliar a interação entre espécies fruteiras e a vegetação sob suas copas na fase de estabelecimento de sistemas silvipastoris no Mato Grosso, Brasil. O experimento foi implantado em 2013 e avaliado em 2015. Estes sistemas foram compostos por oito espécies de fruteiras consorciadas com Tifton-85. O delineamento experimental foi em blocos completos casualizados com duas repetições de área por tratamento. Foi avaliado o desempenho agronômico das espécies fruteiras, caracterização do ambiente luminoso e o acumulo de material vegetal sob as copas. A aceroleira Roxinha apresentou os maiores valores de índice de área foliar (IAF) e interceptação luminosa (IL) devido a um dossel mais denso com baixa porosidade e a menor qualidade de luz disponível sob as copas das árvores (menor relação vermelho/vermelho distante – V/Vd), condicionando a uma redução no acúmulo de material vegetal sob as copas. As goiabeiras cresceram mais do que as outras espécies, contudo apresentaram os menores valores de IAF e IL e alta relação V/Vd, permitindo a presença de mais plantas sob sua copa. Cajazeira demonstrou resposta similar, contudo esta espécie é decídua, podendo apresentar um potencial mais limitado em sistemas integrados. Bananeira e coqueiro mostraram uma grande dependência de irrigação durante a estação seca. As demais espécies apresentaram um crescimento adequado e potencial para controlar o crescimento das plantas sob suas copas
Esporulação e eficiência de infecção do míldio da videira em cenários de mudanças climáticas.
O objetivo deste trabalho foi avaliar o efeito das mudanças climáticas na favorabilidade à ocorrência de míldio (Plasmopara viticola) na região de Bento Gonçalves-RS no período de 2020 a 2050. Este trabalho teve como base modelos de eficiência de infecção (EI) e esporulação (S) que descrevem esses processos com base em temperatura, duração do molhamento e duração de períodos com alta umidade. Para simulações futuras, foram usados os dados de temperatura do modelo climático regional PRECIS nos cenários IPCC A2 e B2 para 2020, 30, 40 e 50. Os resultados indicam pequena diminuição na frequência de dias com EI "alta" (0,7 a 1,0), o que também se reflete em pequena redução nas médias de EI. Por outro lado, ocorre um aumento mais expressivo na S, mais que compensando a perda de EI, resultando em provável maior intensidade da doença no futuro próximo, mantidas as condições de temperatura mais elevada e umidade estável
Physico-chemical and biochemical parameters to highlight quality changes of 'rocha' pear during ca storage
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