Consulta: subjectFacets:"Censored data"
Registros recuperados: 5
Data/hora: 16/06/2024 09:03:13

A Bayesian state-space model to estimate population biomass with catch and limited survey data: application to the thornback ray (Raja clavata) in the Bay of Biscay
Provedor de dados: 5
Autores: Marandel, Florianne; Lorance, Pascal; Trenkel, Verena M.
The thornback ray (Raja clavata) in the Bay of Biscay is presumed to have declined during the 20th Century. To evaluate this decline and estimate biomass trajectories, a hypothetical catch time series was created for the period 1903-2013. A Bayesian state-space biomass production model with a Schaefer production function was fitted to the hypothetical catch time series and to a shorter research vessel Catch Per Unit Eeffort (CPUE) time series (1973-2013, with missing years). A censored likelihood made it possible to obtain biomass estimates without a CPUE time series or only with an estimate of biomass depletion. A simulation-estimation approach showed a high sensitivity of results to the prior for the intrinsic growth rate. The model provided biomass...
Tipo: Text
Palavras-chave: Population dynamics; Stock assessment; Data poor; Censored data; Bayes; Thornback ray; State-space model.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00359/47032/46947.pdf

Censored catch data in fisheries stock assessment
Provedor de dados: 5
Autores: Hammond, T; Trenkel, Verena.
Landings statistics can be lower than true catches because many fish are discarded or landed illegally. Since many discards do not survive, treating landings as true catches can lead to biased stock assessments. This paper proposes treating catch as censored by bounding it below by the landings, L, and above by cL (for scalar c &gt; 1), We demonstrate the approach with a simulation study, using a Schaefer surplus production model. Parameters were estimated in a Bayesian framework with BUGS software using two sets of priors. Both the traditional true-catch method and a survey-and-effort method (which was landings free) performed worse on average than the censored approach, as measured by the Bayes risk associated with estimates of maximum sustainable yield...
Tipo: Text
Palavras-chave: Stock assessment; Misreporting; Discarding; Censored data.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-641.pdf

OLS and Tobit Estimates: When is Substitution Defensible Operationally?
Provedor de dados: 31
Autores: Wilson,   Clevo; Tisdell,   Clement A.
Field data are used to illustrate that, other things constant, regression results using Ordinary Least Squares (OLS) converge to Tobit estimates as the number of zeros in the regressand decrease. Tobit estimates are theoretically superior to OLS estimates when using censored data. However, if little difference exists between OLS and Tobit estimates, OLS may be operationally acceptable. OLS may even be optimal in a bounded rationality sense because the extra cost of using Tobit analysis may be less than the extra benefits from a very slight increase in accuracy.
Tipo: Working or Discussion Paper
Palavras-chave: Bounded rationality; Censored data; Ordinary Least Squares; Tobit; Regressand; Willingness to pay studies.; Public Economics.
Ano: 2002
URL: http://purl.umn.edu/90519

Stings in the tails: Detecting and dealing with censored data
Provedor de dados: 31
Autores: Conroy,   Ronan M.
Variables often show evidence of clustering at extreme values and of graininess, that is, of a limited number of distinct values. Scores on two subscales of a quality-of-life measure, traditionally analyzed with OLS regression or ANOVA models, provide examples. Ignoring or failing to detect such features of the data will result in poor estimates of effect size.
Tipo: Journal Article
Palavras-chave: Censored data; Diagnostic plots; Intreg; Research Methods/ Statistical Methods.
Ano: 2005
URL: http://purl.umn.edu/117528

Improved Bayes estimators and prediction for the Wilson-Hilferty distribution
Provedor de dados: 42
Autores: RAMOS,PEDRO L.; ALMEIDA,MARCO P.; TOMAZELLA,VERA L.D.; LOUZADA,FRANCISCO.
Abstract: In this paper, we revisit the Wilson-Hilferty distribution and presented its mathematical properties such as the r-th moments and reliability properties. The parameters estimators are discussed using objective reference Bayesian analysis for both complete and censored data where the resulting marginal posterior intervals have accurate frequentist coverage. A simulation study is presented to compare the performance of the proposed estimators with the frequentist approach where it is observed a clear advantage for the Bayesian method. Finally, the proposed methodology is illustrated on three real datasets.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bayesian analysis; Bayesian prediction; Censored data; Objective prior; Wilson-Hilferty distribution.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000500202