12,390 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
Comparação da partida de reatores com atividade anammox com diferentes concentrações de inóculo.
Projeto: 02.07.06.007
Detrended Fluctuation Analysis of Systolic Blood Pressure Control Loop
We use detrended fluctuation analysis (DFA) to study the dynamics of blood
pressure oscillations and its feedback control in rats by analyzing systolic
pressure time series before and after a surgical procedure that interrupts its
control loop. We found, for each situation, a crossover between two scaling
regions characterized by exponents that reflect the nature of the feedback
control and its range of operation. In addition, we found evidences of
adaptation in the dynamics of blood pressure regulation a few days after
surgical disruption of its main feedback circuit. Based on the paradigm of
antagonistic, bipartite (vagal and sympathetic) action of the central nerve
system, we propose a simple model for pressure homeostasis as the balance
between two nonlinear opposing forces, successfully reproducing the crossover
observed in the DFA of actual pressure signals
Rotation intrinsic spin coupling--the parallelism description
For the Dirac particle in the rotational system, the rotation induced inertia
effect is analogously treated as the modification of the "spin connection" on
the Dirac equation in the flat spacetime, which is determined by the equivalent
tetrad. From the point of view of parallelism description of spacetime, the
obtained torsion axial-vector is just the rotational angular velocity, which is
included in the "spin connection". Furthermore the axial-vector spin coupling
induced spin precession is just the rotation-spin(1/2) interaction predicted by
Mashhoon. Our derivation treatment is straightforward and simplified in the
geometrical meaning and physical conception, however the obtained conclusions
are consistent with that of the other previous work.Comment: 10 pages, no figur
Progressão de carga em um reator de bancada com atividade anammox.
Projeto/Plano de Ação: 02.07.60700-03
Uniformidade de distribuicao de agua na superficie e no perfil do solo, irrigado com o microaspersor Rain-Bird QN-14.
Foi avaliado, em condições, o Co eficiente de Uniformidade de Christiansen (CUC) das lâminas de água aplicadas na superfície e distribuídas no perfil do solo, nas profundidade de 0-0,20; 0,20-0,40 e 0,40-0,60 m tendo sido obtido, os coeficientes de 42,61; 64,90; 79,04 e 84,06 %, respectivamente. Observou-se também que o Coeficiente de Uniformidade de Christiansen (CUC) da redistribuição d a lâmina de água no perfil do solo aumentou com a profundidade d as camadas
Influência da concentração de nitrogênio em reatores com atividade anammox durante o start-up do sistema.
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