Consulta: subjectFacets:"Bayesian"
Registros recuperados: 15
Data/hora: 10/06/2024 01:19:44

Regresión espacial de precipitaciones extremas en el estado de Tabasco.
Provedor de dados: 32
Autores: Pérez Figueroa, Rebeca Alejandra.
Las precipitaciones extremas en el estado de Tabasco, México, causan pérdidas económicas y serios estragos a los ecosistemas cada año. Esta investigación se basa en el desarrollo de un análisis de eventos de precipitación extrema en Tabasco empleando la información en la base de datos MAYA que comprende observaciones de lluvia diarias para nodos-geográficamente equidistantes. El principal objetivo es proponer un modelo de regresión espacial para datos de precipitaciones extremas con el fin de estimar períodos de retorno vía un modelo jerárquico Bayesiano, y proveer de mapas de riesgo basados en el modelo ajustado así como en la distribución predictiva de precipitación extrema. Se encontró que la localización geográfica incrementa la exactitud en la...
Palavras-chave: Bayesiano; Regresión espacial; Lluvia extrema; Bayesian; Spatial regression; Extreme rainfall; Estadística; Maestría.
Ano: 2012
URL: http://hdl.handle.net/10521/782

Explaining dinophysis cf. acuminata abundance in Antifer (Normandy, France) using dynamic linear regression
Provedor de dados: 5
Autores: Soudant, Dominique; Beliaeff, Benoit; Thomas, G.
Classical regression analysis can be used to model time series. However, the assumption that model parameters are constant over time is not necessarily adapted to the data. In phytoplankton ecology, the relevance of time-varying parameter values has been shown using a dynamic linear regression model (DLRM). DLRMs, belonging to the class of Bayesian dynamic models, assume the existence of a non-observable time series of model parameters, which are estimated on-line, i.e. after each observation. The aim of this paper was to show how DLRM results could be used to explain variation of a time series of phytoplankton abundance. We applied DLRM to daily concentrations of Dinophysis cf. acuminata, determined in Antifer harbour (French coast of the English...
Tipo: Text
Palavras-chave: Phytoplankton; Dinophysis; Time series; Regression; Dynamic; Bayesian.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00337/44784/44490.pdf

Devising quality assurance procedures for assessment of legacy geochronological data relating to deglaciation of the last British-Irish Ice Sheet
Provedor de dados: 5
Autores: Small, David; Clark, Chris D.; Chiverrell, Richard C.; Smedley, Rachel K.; Bateman, Mark D.; Duller, Geoff A. T.; Ely, Jeremy C.; Fabel, Derek; Medialdea, Alicia; Moreton, Steven G.
This contribution documents the process of assessing the quality of data within a compilation of legacy geochronological data relating to the last British-Irish Ice Sheet, a task undertaken as part of a larger community-based project (BRITICE-CHRONO) that aims to improve understanding of the ice sheet's deglacial evolution. As accurate reconstructions depend on the quality of the available data, some form of assessment is needed of the reliability and suitability of each given age(s) in our dataset. We outline the background considerations that informed the quality assurance procedures devised given our specific research question. We describe criteria that have been used to make an objective assessment of the likelihood that an age is influenced by the...
Tipo: Text
Palavras-chave: British-Irish Ice Sheet; Deglaciation; Geochronology; Data compilations; Quality assurance; Bayesian.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00504/61598/65865.pdf

Estimating Synaphobranchus kaupii densities: Contribution of fish behaviour to differences between bait experiments and visual strip transects
Provedor de dados: 5
Autores: Trenkel, Verena; Lorance, Pascal.
Kaup's arrowtooth eel Synaphobranchus kaupii is a small-bodied fish and an abundant inhabitant of the European continental slope. To estimate its local density video information using the remotely operated vehicle (ROV) Victor 6000 were collected at three locations in the Bay of Biscay slope. Two methods for estimating local densities were tested: strip transect counts and bait experiments. For bait experiments three behaviour types were observed in about equal proportions for individuals arriving near the seafloor: moving up the current towards the ROV, moving across the current and drifting with the current. Visible attraction towards the bait was the highest for individuals swimming against the current (80%) and about equally low for the other two types...
Tipo: Text
Palavras-chave: Bayesian; Hierarchical model; Natural and reaction behaviour; Video; Deep-water.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00031/14198/11523.pdf

Update of the English Channel cuttlefish stock assessment with a Bayesian two-stage biomass model.
Provedor de dados: 5
Autores: Alemany, Juliette; Rivot, Etienne; Foucher, Eric; Vigneau, Joel; Robin, Jean-paul.
A two-stage biomass model is developed in the Bayesian framework that allows us to assimilate various sources of information. A method that makes use of ancillary length frequency data is developed to provide an informative prior distribution for the intrinsic biomass growth rate parameter and its annual variability. The new Bayesian model provides substantial improvement to the existing stock assessment method used by ICES. Considering a time-varying g parameter improves model fit and improves the ecological realisms of the model according to the sensitivity of the cuttlefish population dynamics to environmental fluctuations. We present results of the English Channel cuttlefish stock assessment updated with the new Bayesian model. The model also provides...
Tipo: Text
Palavras-chave: Stock assessment; Short-lived species; Data-limited; Cuttlefish; Sepia officinalis; English Channel; Two-stage biomass model; Bayesian.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00377/48775/49173.pdf

Some Estimates of Farmers' Utility Functions
Provedor de dados: 31
Autores: Hildreth,   Clifford; Knowles,   Glenn J.
Utility functions for 13 Minnesota farmers are estimated from their responses to hypothetical decision problems under uncertainty.  The results furnish strong evidence of risk aversion and of decreasing absolute risk aversion as wealth increases.
Tipo: Report
Palavras-chave: Utility; Bayesian; Farmers; Uncertainty; Risk aversion; Decision theory; Cattle; Risk and Uncertainty.
Ano: 1982
URL: http://purl.umn.edu/54545

A Limited Information Bayesian Forecasting Model of the Cattle SubSector
Provedor de dados: 31
Autores: Abidoye,   Babatunde O.; Lawrence,   John D.
The first step towards forecasting the price and output of the cattle industry is understanding the dynamics of the livestock production process. This study follows up on the Weimar and Stillman (1990) paper by using data from 1970 to 2005 to estimate the parameters that characterizes the cattle output supply. The model is then used to estimate forecast values for the periods 2006 and 2007. Bayesian limited information likelihood method is used to estimate the parameters when endogeneity exists between these variables. The forecasting ability of the model for a two-step ahead forecast for majority of the variables are relatively good and test statistic of the forecast are reported.
Tipo: Conference Paper or Presentation
Palavras-chave: Cattle; Bayesian; Forecasting; Inventory; Slaughter; Agribusiness; Agricultural Finance; Financial Economics; Livestock Production/Industries; Marketing; Production Economics; Research Methods/ Statistical Methods.
Ano: 2009
URL: http://purl.umn.edu/53051

Precaution and Protectionism: GM Food and the WTO
Provedor de dados: 31
Autores: Rigby,   Dan; Burton,   Michael P.; Young,   Trevor.
The dispute between the US and EU over GM foods at the WTO is examined in terms of the issues it raises about protectionism and environmental protection and precaution. The issue of whether GM, GM Derived and Non-GM foods are equivalent to each other is examined using data from a national choice modelling study in the UK. These categories of food are critical since they underpin the EU's new food labelling regime which it hoped would defuse the WTO dispute. The results are analysed using a Bayesian mixed logit model which allows greater flexibility in the modelling of preference distributions. This is particularly crucial where, as in this case, bi-modal distributions are identified with some indifferent or mildly averse to GM foodtypes while others are...
Tipo: Conference Paper or Presentation
Palavras-chave: GM food; Mixed logit; WTP; Bayesian; WTO; International Relations/Trade; C11; C24; C25; D12; Q18.
Ano: 2005
URL: http://purl.umn.edu/24447

Precaution and Protectionism: 'Likeness' and GM Food at the WTO
Provedor de dados: 31
Autores: Rigby,   Dan; Burton,   Michael P.; Young,   Trevor.
The dispute between the US and EU over GM foods at the WTO is examined in terms of the issues it raises about protectionism, environmental protection and precaution. The issue of whether GM, GM Derived and Non-GM foods are equivalent to each other is examined using data from a national choice modelling study in the UK. These categories of food are critical since they underpin the EU's new food labelling regime which it hoped would defuse the WTO dispute. The results are analysed using a Bayesian mixed logit model which allows greater flexibility in the modelling of preference distributions than that allowed through classical estimation. The Bayesian approach allows the use of censored normal and Johnson's SB distributions which can accommodate a bounded...
Tipo: Conference Paper or Presentation
Palavras-chave: GM food; Mixed logit; WTP; Bayesian; WTO; International Relations/Trade; Q51; Q55; Q56; Q58.
Ano: 2006
URL: http://purl.umn.edu/25503

Input usage, output mix and industry deregulation: an analysis of the Australian dairy manufacturing industry
Provedor de dados: 31
Autores: Balcombe,   Kelvin George; Doucouliagos,   Hristos; Fraser,   Iain.
In this paper we estimate a Translog output distance function for a balanced panel of state level data for the Australian dairy processing sector. We estimate a fixed effects specification employing Bayesian methods, with and without the imposition of monotonicity and curvature restrictions. Our results indicate that Tasmania and Victoria are the most technically efficient states with New South Wales being the least efficient. The imposition of theoretical restrictions marginally affects the results especially with respect to estimates of technical change and industry deregulation. Importantly, our bias estimates show changes in both input use and output mix that result from deregulation. Specifically, we find that deregulation has positively biased the...
Tipo: Journal Article
Palavras-chave: Bayesian; Deregulation; Output distance function; Agribusiness.
Ano: 2007
URL: http://purl.umn.edu/118324

Modeling Censored Data Using Mixture Regression Models with an Application to Cattle Production Yields
Provedor de dados: 31
Autores: Belasco,   Eric J.; Ghosh,   Sujit K.
This research develops a mixture regression model that is shown to have advantages over the classical Tobit model in model fit and predictive tests when data are generated from a two step process. Additionally, the model is shown to allow for flexibility in distributional assumptions while nesting the classic Tobit model. A simulated data set is utilized to assess the potential loss in efficiency from model misspecification, assuming the Tobit and a zero-inflated log-normal distribution, which is derived from the generalized mixture model. Results from simulations key on the finding that the proposed zero-inflated log-normal model clearly outperforms the Tobit model when data are generated from a two step process. When data are generated from a Tobit...
Tipo: Conference Paper or Presentation
Palavras-chave: Censoring; Livestock production; Tobit; Zero-inflated; Bayesian; Livestock Production/Industries.
Ano: 2008
URL: http://purl.umn.edu/6341

Amenities and Rural Appalachia Economic Growth
Provedor de dados: 31
Autores: Deller,   Steven C.; Lledo,   Victor.
Patterns of economic growth in rural Appalachia are examined with a focus on natural and built amenities. While the literature is clear that rural areas endowed with scenic beauty, lakes, forests, and wildlife, among other natural amenities, and coupled with built amenities such as golf courses, are experiencing robust economic growth. It is not clear if these patterns extend to rural Appalachia. In this applied research study we use data for rural U.S. counties. We estimate an augmented Carlino-Mills growth model with specific attention to growth patterns of Appalachia. We also build on the empirical modeling by adopting a Bayesian Modeling Average (BMA) approach to address the problem of model specification. We find that while there are some...
Tipo: Journal Article
Palavras-chave: Amenities; Quality of life; Rural economic growth; Bayesian; Community/Rural/Urban Development.
Ano: 2007
URL: http://purl.umn.edu/10153

Single-trait bayesian analysis of some growth traits in japanese quail
Provedor de dados: 89
Autores: Karaman,E; Firat,MZ; Narinc,D.
The aim of this study was to estimate the heritability for some growth traits of Japanese quail through the estimation of variance components by Bayesian methodology. For this purpose, 340 progenies of 34 sires were used. Live weight (LW42) and absolute and relative growth rates at 42 days of age (AGR42 and RGR42, respectively) were submitted to single-trait analysis under a sire model. A software (package MCMCglmm) was used for the estimations, and a single chain with 65,000 rounds was run for each trait with a thinning interval of 50. Burn-in was set at 15,000 and inferences were built on posterior samples of 1,000 draws for each trait. All marginal posterior densities were unimodal and marginal posterior distributions of sire variance are slightly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Absolute growth rate; Bayesian; Heritability; Quail; Relative growth rate.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2014000200007

Bayesian Analysis for the Comparison of Nonlinear Regression Model Parameters: an Application to the Growth of Japanese Quail
Provedor de dados: 89
Autores: Firat,MZ; Karaman,E; Başar,EK; Narinc,D.
ABSTRACT This paper discusses the Bayesian approach as an alternative to the classical analysis of nonlinear models for growth curve data in Japanese quail. A Bayesian nonlinear modeling method is introduced and compared with the classical nonlinear least squares (NLS) method using three non-linear models that are widely used in modeling the growth data of poultry. The Gompertz, Richards and Logistic models were fitted to 499 Japanese quail weekly averaged body weight data. Normal prior was assumed for all growth curve parameters of the models with assuming Jeffreys' non-informative prior for residual variances. Models were compared based on the Bayesian measure of fit, deviance information criterion (DIC), and our results indicated the better fit of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gompertz; Logistic; Richards; Non-linear; Bayesian.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2016000500019

Estimation of genetic parameters for growth traits in Tabapuã cattle using a multi-trait model
Provedor de dados: 96
Autores: Menezes,Gilberto Romeiro de Oliveira; Torres,Robledo de Almeida; Torres Júnior,Roberto Augusto de Almeida; Silva,Luiz Otávio Campos da; Gondo,Andrea; Euclydes,Ricardo Frederico.
To provide information that can contribute to the genetic evaluation and selection in Tabapuã cattle, genetic parameters were estimated for growth traits using a multi-trait animal model. (Co)variance components were estimated by a Bayesian approach using the Gibbs Sampler. Moderate and similar responses to selection are expected when selecting for weights at the four ages evaluated, since the direct heritability estimates were similar and of average magnitude (0.18 to 0.19). The direct and maternal additive genetic correlations between all pairs of weights were higher than 0.70, indicating a high degree of association between the four traits. This suggests that using any of them as selection criteria will result in correlated response in the others and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bayesian; Beef cattle; (co)variance components; Genetic evaluation; Selection.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000800006