Stable Distributions
Mostrando 1-12 de 76 artigos, teses e dissertações.
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1. Practical rules for summing the series of the Tweedie probability density function with high-precision arithmetic
Abstract: For some ranges of its parameters and arguments, the series for Tweedie probability density functions are sometimes exceedingly difficult to sum numerically. Existing numerical implementations utilizing inversion techniques and properties of stable distributions can cope with these problems, but no single one is successful in all cases. In this wor
An. Acad. Bras. Ciênc.. Publicado em: 02/12/2019
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2. SOME COMPUTATIONAL ASPECTS TO FIND ACCURATE ESTIMATES FOR THE PARAMETERS OF THE GENERALIZED GAMMA DISTRIBUTION
ABSTRACT In this paper, we discuss computational aspects to obtain accurate inferences for the parameters of the generalized gamma (GG) distribution. Usually, the solution of the maximum likelihood estimators (MLE) for the GG distribution have no stable behavior depending on large sample sizes and good initial values to be used in the iterative numerical alg
Pesqui. Oper.. Publicado em: 2017-08
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3. MOLECULAR THERMODYNAMICS OF MICELLIZATION: MICELLE SIZE DISTRIBUTIONS AND GEOMETRY TRANSITIONS
Abstract Surfactants are amphiphilic molecules that can spontaneously self-assemble in solution, forming structures known as micelles. Variations in temperature, pH, and electrolyte concentration imply changes in the interactions between surfactants and micelle stability conditions, including micelle size distribution and micelle shape. Here, molecular therm
Braz. J. Chem. Eng.. Publicado em: 2016-09
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4. A ‘Universal’ Bottom-up Sol-gel Based Synthesis of Pzt (1-x)/x Submicrometric Structures: 1. Dynamic Light Scattering Characterization of Precursor Stability and Aggregation Kinetics
This work proposes an extension of a sol-gel based synthesis route for obtaining highly hydrophobic, uniformly nanosized and stable precursor solutions of lead zirconate titanate [Pb(Zr1-xTix)O3 or PZT (1-x)/x] for any given (1-x)/x Zr:Ti ratio. Several representative PZT compositions were chosen and their precursors were studied by taking into account the t
Mat. Res.. Publicado em: 25/08/2015
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5. Particle size and cholesterol content of a mayonnaise formulated by OSA-modified potato starch
Egg yolk was partially replaced (0, 25, 50, 75, and 100%) with octenyl succinic anhydride (OSA)-modified potato starch in a reduced-fat mayonnaise formulation to curtail the problems associated with high cholesterol and induced allergic reactions. The physicochemical properties included parameters such as: pH, fat content, and emulsion stability of the formu
Food Sci. Technol. Publicado em: 2015-03
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6. Simulação de um alimentador Venturi em trecho ascendente no transporte pneumático de sólidos
The radial and axial distributions of coarse solids when fed directly in a riser are unknown, despite this type of feeding is very important for drying and preheating of solids during conveying. In this context, this thesis focused on studying the diluted conveying of coarse solids in a riser that was fed by a Venturi feeder in vertical orientation. Experime
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/08/2012
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7. Estimação indireta de modelos R-GARCH / Indirect inference of R-GARCH models
Linear processes do not capture the structure of financial data. There is a large variety of nonlinear models available in literature. The class of ARCH models (Autoregressive Conditional Heterokedastic) was introduced by Engle (1982) in order to estimate inflation\ s variance. The idea is that, in this class, returns are serially uncorrelated, but the volat
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/03/2012
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8. Comparação das distribuições α-estável, normal, t de student e Laplace assimétricas
As distribuições assimétricas tem experimentado grande desenvolvimento nos tempos recentes. Elas são utilizadas na modelagem de dados financeiros, médicos e genéticos entre outras aplicações. Dentre essas distribuições, a normal assimétrica (Azzalini, 1985) tem recebido mais atenção dos pesquisadores (Genton et al., (2001), Gupta et al., (2004)
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/01/2012
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9. Ion-polymer interaction analysis: an inversion of NMR spin echo experimental data
A methodology for ion-polymer interaction estimation is discussed in the present work. This method is based on the inversion of experimental spin echo NMR data using Hopfield neural network to retrieve transverse relaxation time distributions. The adopted model systems consist of aqueous solutions of poly (ethylene oxide), molar mass 1500, 4000 and 35000 γ
Brazilian Journal of Physics. Publicado em: 2010-12
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10. CARACTERIZAÇÃO TECNOLÓGICA DE UM SINTER FEED HEMATÍTICO CONTENDO DIFERENTES PROPORÇÕES E TIPOS DE SÍLICA NAS FRAÇÕES ADERENTES, INTERMEDIÁRIAS E NUCLEANTES
There are important Vale iron ore reserves located in the state of Minas Gerais. The hematite/itabirite relationship in the ROMs has been decreasing compared to the last decade. The beneficiation plants have been concentrating its efforts on reducing the silica content in the sinter feed in order to reach the quality levels demanded for the sintering process
Publicado em: 2010
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11. Study of the interaction of mass A=8 nuclei with carbon target and of the capture reaction 8Li(p,y)9Be of astrophysical interest / Estudo da interação de núcleos de massa A=8 com alvo de carbono e da reação de captura 8Li(p,)9Be de interesse astrofísico
The measurements of the angular distributions for the elastic scatterings 12C(Li,Li) and 12C(8B,8B) reported in this work have been done in two laboratories. Those corresponding to the angular distributions for the elastic scattering 12C(8Li,8Li) were performed at two ene&ies, 20.6 MeV and 23.9 MeV, at the Pelletron Laboratory of the University of São Paulo
Publicado em: 2009
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12. Ecologia e modelagem da distribuição dos sítios de nidificação do jacaré-açu (Melanosuchus niger) em uma área de várzea da Amazônia Central, Brasil
The black caiman, Melanosuchus niger, is primarily an Amazonian species, its largest populations are associated mainly with interior várzea areas, but its nesting ecology related with these hydrologic dynamic environments is still poorly understood. The objectives of this study were related to the generation of information on the nesting ecology of this spe
Publicado em: 2009