Results 41 to 50 of about 62,351 (294)
Clustering Algorithm Reveals Dopamine‐Motor Mismatch in Cognitively Preserved Parkinson's Disease
Annals of Clinical and Translational Neurology, EarlyView.ABSTRACT Objective To explore the relationship between dopaminergic denervation and motor impairment in two de novo Parkinson's disease (PD) cohorts. Methods n = 249 PD patients from Parkinson's Progression Markers Initiative (PPMI) and n = 84 from an external clinical cohort.
Rachele Malito +14 more
wiley +1 more source
On stratified ranked set sampling for the quest of an optimal class of estimators
Alexandria Engineering JournalIn the sample survey theory, the crux of survey practitioners is to provide “accurate” estimators of the parameter of choice. The conventional theory depends on the regression/difference estimators as they correspond to the best linear unbiased (BLU ...
Shashi Bhushan +5 more
doaj +1 more source
Comparing Sampling and Estimation Strategies in Establishment Populations
Survey Research Methods, 2009 Population structure is a key determinant of the efficiency of sampling plans and estimators. Variables in many establishment populations have structures that can be described by simple linear models with a single auxiliary variable and a variance ...
Kimberly A Henry, Richard Valliant
doaj +1 more source
Forest Ecosystems, 2020 Background Large area forest inventories often use regular grids (with a single random start) of sample locations to ensure a uniform sampling intensity across the space of the surveyed populations.
Steen Magnussen +6 more
doaj +1 more source
Statistica, 2023 Ranked set sampling (RSS) is an efficient technique for estimating parameters and is applicable whenever ranking on a set of sampling units can be done easily by a judgment method or based on an auxiliary variable.
Kirtee Kiran Kamalja, Rohan Dilip Koshti
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Moment properties of estimators for an extreme value regression model with type 2 censoring [PDF]
, 1986 An extreme value regression model for grouped data with type 2 censoring is considered. The response variable is taken to have a type 1 ext reme va lue d i s t r i b u t i on for sma l l e s t v a l ue s a nd a s tandar d linear regression model is ...
Haddow, AA, Young, DH
core
On the non-existence of unbiased estimators in constrained estimation problems [PDF]
, 2017 We address the problem of existence of unbiased constrained parameter estimators. We show that if the constrained set of parameters is compact and the hypothesized distributions are absolutely continuous with respect to one another, then there exists no ...
Leshem, Amir +2 more
core +1 more source
Annals of Clinical and Translational Neurology, EarlyView.ABSTRACT Objective Cognitive decline is a disabling and variable feature of Parkinson disease (PD). While cholinergic system degeneration is linked to cognitive impairments in PD, most prior research reported cross‐sectional associations. We aimed to fill this gap by investigating whether baseline regional cerebral vesicular acetylcholine transporter ...
Taylor Brown +6 more
wiley +1 more source
On decompositions of estimators under a general linear model with partial parameter restrictions
Open Mathematics, 2017 A general linear model can be given in certain multiple partitioned forms, and there exist submodels associated with the given full model. In this situation, we can make statistical inferences from the full model and submodels, respectively.
Jiang Bo, Tian Yongge, Zhang Xuan
doaj +1 more source
Improved robust Bayes estimators of the error variance in linear models
, 2013 We consider the problem of estimating the error variance in a general linear model when the error distribution is assumed to be spherically symmetric, but not necessary Gaussian.
Maruyama, Yuzo, Strawderman, William E.
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