Consulta: subjectFacets:"Probability distributions"
Registros recuperados: 5
Data/hora: 27/07/2024 02:53:19

A UNIFIED APPROACH TO SENSITIVITY ANALYSIS IN EQUILIBRIUM DISPLACEMENT MODELS: COMMENT
Provedor de dados: Research in Agricultural & Applied Economics (AgEcon Searh)
Autores: Griffiths,   William E.; Zhao,   Xueyan.
It is pointed out that the Chebychev confidence intervals and maximum p-values advocated by Davis and Espinoza for sensitivity analysis of equilibrium displacement models are unnecessary. Desired probability intervals and probabilities can be accurately estimated without resorting to gross approximations.
Tipo: Working or Discussion Paper
Palavras-chave: Simulation; Probability distributions; Empirical quantiles; Research Methods/ Statistical Methods.
Ano: 1999
URL: http://purl.umn.edu/12950

Best distribution and plotting positions of daily maximum flood estimation at Ona River in Ogun-Oshun river basin, Nigeria
Provedor de dados: Agricultural Engineering International : The CIGR e-journal
Autores: Temitayo Abayomi EWEMOJE; Department of Agricultural and Environmental Engineering, University of Ibadan; O. S. Ewemooje; Department of Statistics, University of Ibadan.
The paper discusses how Normal, Lognormal, and log-Pearson type 3 distributions were investigated as distributions for modelling at-site annual maximum flood flows using the Hazen, Weibull, and California plotting positions at Ogun-Oshun river basin in Nigeria.  All the probability distributions when matched with Weibull plotting position gave similar values near the center of the distribution but varied considerably in the tails.  The Weibull plotting position when matched with Normal, Log-normal and Log Pearson Type III probability distributions gave the highest coefficient of determinations of 0.967, 0.987, and 0.986 respectively.  Hazen plotting position gave minimal errors with the RMSE of 6.988, 6.390, and 6.011 for Normal, Log-normal, and...
Palavras-chave: Probability distributions; Plotting positions; Maximum flood; Estimation; Statistical modelling; Nigeria.
Ano: 2011
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/1380

Point, alpha and beta diversity of carnivorous fish along a depth gradient
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Lorance, Pascal; Souissi, Sami; Uiblein, Franz.
The catch from bottom longline stations sampled from a series of research cruises around Lanzarote and Fuerteventura (Canary Islands, NE Atlantic) was analysed in terms of fish distribution, density and diversity. The distribution of the number of species and individuals caught per station appeared to fit well the Poisson and Exponential distribution function, respectively. In particular, the parameter of the Poisson's distribution appeared to provide an index of the point (at station scale) diversity, and its confidence interval, allowing for statistical comparisons. The relationships between point diversity, the alpha diversity (in the depth strata) and the beta diversity (along the depth gradient) were investigated. Around the islands, the density and...
Tipo: Text
Palavras-chave: Canary Islands; Probability distributions; Density; Diversity; Demersal fishes; Longline.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/2002/publication-566.pdf

Spatial distribution of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) in citrus orchards
Provedor de dados: Scientia Agricola
Autores: Costa,Marilia Gregolin; Barbosa,José Carlos; Yamamoto,Pedro Takao; Leal,Renata Moreira.
The psyllid Diaphorina citri Kuwayama is one of the most important pests of citrus, mainly because it is the vector of the bacterium that causes huanglongbing (HLB) or 'Greening' disease. To study the spatial distribution of nymphs and adults of this pest, an experiment was carried out in two 'Valencia' sweet orange orchards, four and 12 years of age, established in Matão, central area of São Paulo state, Brazil. The following dispersion indices were used to study pest aggregation in the citrus plants: variance/mean relationship (I), index of Morisita (Iδ), coefficient of Green (Cx), the &lt;img border=0 width=16 height=16 src="../../../../../img/revistas/sa/v67n5/a08form10.gif" align=absmiddle&gt;exponent of negative binomial distribution, common k...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus sinensis; Psyllid; Probability distributions; Negative binomial distribution.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162010000500008

The Economic Impact and the Distribution of Benefits and Risk from the Adoption of Insect Resistant (Bt)  Cotton in West Africa
Provedor de dados: Research in Agricultural & Applied Economics (AgEcon Searh)
Autores: Falck-Zepeda,   Jose Benjamin; Horna,   J. Daniela; Smale,   Melinda.
Cotton is the largest source of export receipts of several West African countries. Statistics however show a decreasing tendency in cotton yields and an increasing tendency in pesticide use. Under this circumstances there appear to be potential payoffs from the use of biotechnology products in the farming systems of the region. In this study we estimate different scenarios for the potential deployment of insect resistant cotton in selected countries in West Africa (WA). We use an economic surplus model augmented with a more rigorous sensitivity analysis of model parameters. Hypothetical scenarios of Bt cotton adoption in WA are simulated and single point values of model parameters are substituted with probability distributions. The scenarios include: no...
Tipo: Working or Discussion Paper
Palavras-chave: Bt cotton; West Africa; Economic surplus; Risk; Probability distributions; Impact assessment; Net benefits; Crop Production/Industries.
Ano: 2007
URL: http://purl.umn.edu/42395