Results 11 to 20 of about 34,245 (290)

Generalized ridge estimator shrinkage estimation based on particle swarm optimization algorithm [PDF]

open access: yesالمجلة العراقية للعلوم الاحصائية, 2020
It is well-known that in the presence of multicollinearity, the ridge estimator is an alternative to the ordinary least square (OLS) estimator. Generalized ridge estimator (GRE) is an generalization of the ridge estimator.
Qamar Abdul kareem, Zakariya Algamal
doaj   +1 more source

PROPOSED SHRINKAGE FUNCTION FOR A SINGLE OBSERVATION IN N(Θ,1) PROBLEM [PDF]

open access: yesمجلة جامعة الانبار للعلوم الصرفة, 2012
In this search, Shrinkage Function has been suggested for a Single Observation in N(θ,1) problem. We proved that there is a relationship between Shrinkage Estimator and Normal Bayes Estimator. properties of Proposed Estimator, optimal case, properties of
AMER FADHEL NASSAR
doaj   +1 more source

Cluster-seeking shrinkage estimators [PDF]

open access: yes2016 IEEE International Symposium on Information Theory (ISIT), 2016
This paper considers the problem of estimating a high-dimensional vector θ ∈ ℝn from a noisy one-time observation. The noise vector is assumed to be i.i.d. Gaussian with known variance. For the squared-error loss function, the James-Stein (JS) estimator is known to dominate the simple maximum-likelihood (ML) estimator when the dimension n exceeds two ...
Koteshwar Srinath, P, Venkataramanan, R
openaire   +1 more source

Shrinkage estimation of the regression parameters with multivariate normal errors [PDF]

open access: yesIranian Journal of Numerical Analysis and Optimization, 2008
In the linear model y=XB+e with the errors distributed as normal, we obtain generalized least square (GLS), restricted GLS (RGLS), preliminary test (PT), Stein-type shrinkage (S) and positive-rule shrinkage (PRS) estimators for regression vector ...
M. Arashi, S. M. M. Tabatabaey
doaj   +1 more source

Shrinkage Estimators for Covariance Matrices [PDF]

open access: yesBiometrics, 2001
Estimation of covariance matrices in small samples has been studied by many authors. Standard estimators, like the unstructured maximum likelihood estimator (ML) or restricted maximum likelihood (REML) estimator, can be very unstable with the smallest estimated eigenvalues being too small and the largest too big.
Daniels, Michael J., Kass, Robert E.
openaire   +3 more sources

Composition Estimation Via Shrinkage

open access: yesSSRN Electronic Journal, 2022
In this note, we explore a simple approach to composition estimation, using penalized likelihood density estimation on a nominal discrete domain. Practical issues such as smoothing parameter selection and the use of prior information are investigated in simulations, and a theoretical analysis is attempted. The method has been implemented in a pair of R
openaire   +2 more sources

Designing experiments toward shrinkage estimation

open access: yesElectronic Journal of Statistics, 2023
We consider how increasingly available observational data can be used to improve the design of randomized controlled trials (RCTs). We seek to design a prospective RCT, with the intent of using an Empirical Bayes estimator to shrink the causal estimates from our trial toward causal estimates obtained from an observational study.
Rosenman, Evan T. R., Miratrix, Luke
openaire   +3 more sources

On Some Classes of Estimators Derived from the Positive Part of James–Stein Estimator

open access: yesJournal of Mathematics, 2023
This work consists of developing shrinkage estimation strategies for the multivariate normal mean when the covariance matrix is diagonal and known. The domination of the positive part of James–Stein estimator (PPJSE) over James–Stein estimator (JSE ...
Abdenour Hamdaoui   +5 more
doaj   +1 more source

Generalized robust shrinkage estimator and its application to STAP detection problem [PDF]

open access: yes, 2014
Recently, in the context of covariance matrix estimation, in order to improve as well as to regularize the performance of the Tyler's estimator [1] also called the Fixed-Point Estimator (FPE) [2], a "shrinkage" fixed-point estimator has been introduced ...
Chitour, Yacine   +2 more
core   +2 more sources

Jeffreys-prior penalty, finiteness and shrinkage in binomial-response generalized linear models [PDF]

open access: yes, 2020
Penalization of the likelihood by Jeffreys' invariant prior, or by a positive power thereof, is shown to produce finite-valued maximum penalized likelihood estimates in a broad class of binomial generalized linear models.
Firth, David, Kosmidis, Ioannis
core   +2 more sources

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