Results 71 to 80 of about 9,759 (265)

Information Geometry for Covariance Estimation in Heterogeneous Clutter with Total Bregman Divergence

open access: yesEntropy, 2018
This paper presents a covariance matrix estimation method based on information geometry in a heterogeneous clutter. In particular, the problem of covariance estimation is reformulated as the computation of geometric median for covariance matrices ...
Xiaoqiang Hua   +3 more
doaj   +1 more source

Canagliflozin Alleviates Diabetic Glomerular Endothelial Injury via Melibiose in a Microbiota‐Dependent Manner

open access: yesAdvanced Science, EarlyView.
Canagliflozin treatment reshapes the gut microbiota in DKD and elevates levels of melibiose, a metabolite derived from Roseburia intestinalis. Melibiose directly binds to and enhances the enzymatic activity of glyoxalase 1, leading to decreased methylglyoxal accumulation.
Wei Zhang   +32 more
wiley   +1 more source

Object-oriented Computation of Sandwich Estimators

open access: yesJournal of Statistical Software, 2006
Sandwich covariance matrix estimators are a popular tool in applied regression modeling for performing inference that is robust to certain types of model misspecification.
Achim Zeileis
doaj   +3 more sources

Microscale Mapping of Fiber Strain and Damage in Composite Wrinkled Laminates Using Computed Tomography Assisted Wide‐Angle X‐Ray Scattering

open access: yesAdvanced Science, EarlyView.
This study combines full‐field tomography with diffraction mapping to quantify radial (ε002$\varepsilon _{002}$) and axial (ε100$\varepsilon _{100}$) lattice strain in wrinkled carbon‐fiber specimens for the first time. Radial microstrain gradients (−14.5 µεMPa$\varepsilon \mathrm{MPa}$−1) are found to signal damage‐prone zones ahead of failure, which ...
Hoang Minh Luong   +7 more
wiley   +1 more source

Consistent Estimators of the Population Covariance Matrix and Its Reparameterizations

open access: yesMathematics
For the high-dimensional covariance estimation problem, when limn→∞p/n=c∈(0,1), the orthogonally equivariant estimator of the population covariance matrix proposed by Tsai and Tsai exhibits certain optimal properties.
Chia-Hsuan Tsai, Ming-Tien Tsai
doaj   +1 more source

Large‐Scale Genomics Reveals Three‐Source Ancestry and Layered Adaptation to High Altitude in Tibetan Chickens

open access: yesAdvanced Science, EarlyView.
Whole‐genome analysis of 1,054 chickens reveals three ancestral sources (NWC, SYA, and SHF) with distinct temporal entry patterns into the Tibetan Plateau. Route‐specific selection scans, calibrated against a demographic null, suggest complementary functional enrichments—vascular homeostasis (NWC), calcium signaling and cardiac adaptation (SYA), and ...
Zongyi Zhao   +7 more
wiley   +1 more source

Statistical Inference for Gompertz Distribution based on Progressive Type-II Censored Data with Binomial Removals

open access: yesStatistica, 2018
In this paper, the problem of estimation of parameters for a two-parameterGompertz distribution is considered based on a progressively type-II censored sample with binomial removals.
Manoj Chacko, Rakhi Mohan
doaj   +1 more source

Triple‐Mode Ferroelectric Thin‐Film Transistor for Hybrid Electrical–Optical Reservoir Computing

open access: yesAdvanced Science, EarlyView.
A triple‐mode ferroelectric thin‐film transistor is developed by integrating Si3N4/HZO/IGZO layers to realize three independent memory modes: electric long‐term, electric short‐term, and optical short‐term. This single‐device architecture functions as both a reservoir and readout layer, achieving 92.43% MNIST accuracy. It offers a fully hardware‐based,
Hyeonho Lee   +9 more
wiley   +1 more source

HOTELLING'S T2 CONTROL CHARTS BASED ON ROBUST ESTIMATORS

open access: yesDyna, 2010
Under the presence of multivariate outliers, in a Phase I analysis of historical set of data, the T 2 control chart based on the usual sample mean vector and sample variance covariance matrix performs poorly.
SERGIO YÁÑEZ   +2 more
doaj  

Performance of some estimators for the multicollinear logistic regression model: theory, simulation, and applications

open access: yesResearch in Statistics
This article proposes some new estimators, namely Stein’s estimators for ridge regression and Kibria and Lukman estimator and compares their performance with some existing estimators, namely maximum likelihood estimator (MLE), ridge regression estimator,
Md Ariful Hoque, B. M. Golam Kibria
doaj   +1 more source

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