Results 51 to 60 of about 1,170 (203)

A Stochastic Condensation Mechanism for Inducing Underdispersion in Count Models

, 2021
It is quite easy to stochastically distort an original count variable to obtain a new count variable with relatively more variability than in the original variable. Many popular overdispersion models (variance greater than mean) can indeed be obtained by mixtures, compounding or randomlystopped sums.
Chenangnon Frédéric Tovissodé, Romain Glele Kakai   +1 more
openaire   +2 more sources

Automated detection of over- and under-dispersion in baseline tables in randomised controlled trials [version 2; peer review: 2 approved]

F1000Research, 2023
Background: Papers describing the results of a randomised trial should include a baseline table that compares the characteristics of randomised groups.
Adrian Barnett
doaj   +1 more source

A structurally localized ensemble Kalman filtering approach

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We derive an inherently localized ensemble Kalman filtering (EnKF) approach, avoiding the need for any auxiliary localization technique. The idea is to first use the variational Bayesian optimization to approximate the (continuous) state analysis probability density function (pdf) by a product of independent marginal pdfs corresponding to small ...
Boujemaa Ait‐El‐Fquih, Ibrahim Hoteit   +1 more
wiley   +1 more source

NowPrecip 2: Precipitation nowcasting in the complex terrain of Switzerland. Part II: Verification

Quarterly Journal of the Royal Meteorological Society, EarlyView.
In this work we present the verification of the NowPrecip precipitation nowcasting systems (version 1 and version 2). Using 3.5 years of data over the period 2020–2023, their performance is compared with PySTEPS and the ICON numerical weather prediction ensemble by computing deterministic and probabilistic metrics.
A. Ntoumos, I. V. Sideris, A. Berne, A. Hering, P. Juda, M. Gabella, M. Boscacci, L. Clementi, U. Germann   +8 more
wiley   +1 more source

Underdispersion of anti-herbivore defence traits and phylogenetic structure of cerrado tree species at fine spatial scale

, 2015
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Question Do species phylogeny and herbivory-related ...
Batalha, MA, Loiola, PP, Silva, DM, Silva, IA   +3 more
core   +1 more source

Robustness of serial clustering of extratropical cyclones to the choice of tracking method

Tellus: Series A, Dynamic Meteorology and Oceanography, 2016
Cyclone clusters are a frequent synoptic feature in the Euro-Atlantic area. Recent studies have shown that serial clustering of cyclones generally occurs on both flanks and downstream regions of the North Atlantic storm track, while cyclones tend to ...
Joaquim G. Pinto, Sven Ulbrich, Theodoros Economou, David B. Stephenson, Melanie K. Karremann, Len C. Shaffrey   +5 more
doaj   +1 more source

Multivariate generalized linear mixed models for underdispersed count data

Journal of Statistical Computation and Simulation, 2023
Researchers are often interested in understanding the relationship between a set of covariates and a set of response variables. To achieve this goal, the use of regression analysis, either linear or generalized linear models, is largely applied. However, such models only allow users to model one response variable at a time. Moreover, it is not possible
Guilherme Parreira da Silva, Henrique Aparecido Laureano, Ricardo Rasmussen Petterle, Paulo Justiniano Ribeiro Jr, Wagner Hugo Bonat   +4 more
openaire   +2 more sources

Are we misdiagnosing ensemble forecast reliability? On the insufficiency of spread–error and rank‐based reliability metrics

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We demonstrate that the spread–error relationship, rank histogram, and continuous rank probability score reliability component can falsely indicate reliability under climatological variance biases, yielding ensemble members that are overly or insufficiently extreme.
Arlan Dirkson, Mark Buehner
wiley   +1 more source

The Touchard Process for Count Data with Dependent Increments

Mathematics
This paper introduces the Touchard process, a flexible two-parameter stochastic framework for modeling count data that depart from the classical Poisson assumptions.
Moisés Lima, Gladston Da Silva, Regina Da Fonseca, Raul Matsushita   +3 more
doaj   +1 more source

Ensemble reliability and the signal‐to‐noise paradox in ECMWF subseasonal forecasts

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We derive a general expression for the ratio of predictable components (RPC) in terms of correlation, spread–error ratio, and total variance ratio. Physical constraints on the admissible solutions (i.e., real‐valued and non‐negative variances) provide a mechanism to identify statistically paradoxical sample combinations of reliability and correlation ...
Christopher D. Roberts, Frederic Vitart
wiley   +1 more source