Results 121 to 130 of about 4,500,411 (350)
Nonparametric estimation of covariance functions by model selection [PDF]
, 2009 We propose a model selection approach for covariance estimation of a stochastic process. Under very general assumptions, observing i.i.d replications of the process at fixed observation points, we construct an estimator of the covariance function by ...
Muniz Alvarez, Lilian +9 more
core +1 more source
Advanced Science, EarlyView.This study investigates how the internal structure of fiber‐reinforced ceramic composites affects their resistance to damage. By combining 3D X‐ray imaging with acoustic emission monitoring during mechanical testing, it reveals how silicon distribution influences crack formation.
Yang Chen +7 more
wiley +1 more source
Machine Learning Diagnosis and Local Shrinkage of Covariance-Level Pathologies in SEM
MathematicsNon-convergence in small-sample structural equation modeling (SEM) is frequently driven by localized pathologies in the sample covariance matrix—specific covariance patterns that, for a given model specification, substantially elevate the risk of non ...
Leonard Vanbrabant, Yves Rosseel
doaj +1 more source
Bootstrapping heteroskedasticity consistent covariance matrix estimator [PDF]
Recent results of Cribari-Neto and Zarkos (1999) show that bootstrap methods can be successfully used to estimate a heteroskedasticity robust covariance matrix estimator. In this paper, we show that the wild bootstrap estimator can be calculated directly,
Emmanuel Flachaire
core
Advanced 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
Selenium Nanoparticles Selectively Target KRAS G13D to Inhibit Colorectal Cancer
Advanced Science, EarlyView.The mechanisms of SeNPs therapy in cancer treatment, encompass three parallel actions: (1) seleno‐amino acids, key metabolites, upregulate GPX2 expression, thereby inhibiting tumor metastasis via the GPX2‐HIF1α‐VEGF signaling pathway; (2) selenite (SeO32−), an inorganic metabolite, forms hydrogen bonds with amino acid residues 13–17 of the KRAS G13D ...
Xiaoting Liu +13 more
wiley +1 more source
Advanced Science, EarlyView.Decoupling biological signals from unwanted variation in multi‑condition single‑cell RNA sequencing data remains challenging. CAPER disentangles condition‑associated biological effects from sample heterogeneity through matrix factorization, producing interpretable latent factors and a batch‑corrected expression matrix.
Ye Li +6 more
wiley +1 more source
Probing the covariance matrix [PDF]
AIP Conference Proceedings, 2006 By drawing an analogy between the logarithm of a probability distribution and a physical potential, it is natural to ask the question, “what is the effect of applying an external force on model parameters?” In Bayesian inference, parameters are frequently estimated as those that maximize the posterior, yielding the maximum a posteriori (MAP) solution ...
openaire +1 more source
Advanced Science, EarlyView.Multi‐trait genome‐wide association mapping identifies a central hub regulator, COLD AND CATECHINS REGULATOR 1 (CCR1), and its excellent natural allele variation, coordinately enhancing cold tolerance and promoting catechins biosyntheis. CsCCR1 interacts with CsCBF1/3 and is transcriptionally activated by CsLUX and CsKUA1 to promote catechins ...
Yanli Wang +10 more
wiley +1 more source
Testing of a Structures Covariance Matrix for Three-Level Repeated Measures Data. [PDF]
This paper considers the problem of estimating, and testing for, a Kronecker product covariance structure of three-level (multiple time points (p), multiple sites (u), and multiple response variables (q)) multivariate data.
Ricardo Leiva, Anuradha Roy
core