Results 111 to 120 of about 285,691 (282)

Estimating covariance matrices II

Journal of Multivariate Analysis, 1991
AbstractLet S1 and S2 be two independent p × p Wishart matrices with S1 ∼ Wp(Σ1, n1) and S2 ∼ Wp(Σ2, n2). We wish to estimate ζ = Σ2Σ1−1 under the loss function L1 = tr(ζ − ζ)′ Σ2−1(ζ − ζ) Σ1tr ζ. By extending the techniques of Berger, Haff, and Stein for the one sample problem, alternative estimators to the usual estimators for ζ are obtained. However,
openaire   +1 more source

His‐MMDM: Multi‐Domain and Multi‐Omics Translation of Histopathological Images with Diffusion Models

Advanced Science, EarlyView.
His‐MMDM is a diffusion model‐based framework for scalable multi‐domain and multi‐omics translation of histopathological images, enabling tasks from virtual staining, cross‐tumor knowledge transfer, and omics‐guided image editing. ABSTRACT Generative AI (GenAI) has advanced computational pathology through various image translation models.
Zhongxiao Li, Tianqi Su, Bin Zhang, Wenkai Han, Sibin Zhang, Guiyin Sun, Yuwei Cong, Xin Chen, Jiping Qi, Yujie Wang, Shiguang Zhao, Hongxue Meng, Peng Liang, Xin Gao   +13 more
wiley   +1 more source

Constrained Covariance Matrices With a Biologically Realistic Structure: Comparison of Methods for Generating High-Dimensional Gaussian Graphical Models

Frontiers in Applied Mathematics and Statistics, 2019
High-dimensional data from molecular biology possess an intricate correlation structure that is imposed by the molecular interactions between genes and their products forming various different types of gene networks.
Frank Emmert-Streib, Frank Emmert-Streib, Shailesh Tripathi, Shailesh Tripathi, Matthias Dehmer, Matthias Dehmer, Matthias Dehmer   +6 more
doaj   +1 more source

Cognitive Trajectories from Preclinical Alzheimer's Disease to Dementia

Advanced Science, EarlyView.
A continuous, multi‐domain characterization of cognitive decline across the Alzheimer's disease spectrum identifies when individual cognitive measures become abnormal. Episodic memory declines first, followed by executive function, language, processing speed, and visuospatial abilities, supporting improved clinical interpretation and optimized endpoint
Fredrik Öhman, Lars Lau Raket, Michael Schöll, for the Alzheimer's Disease Neuroimaging Initiative†   +3 more
wiley   +1 more source

An Expectation-Maximization Algorithm for Combining a Sample of Partially Overlapping Covariance Matrices. [PDF]

Axioms, 2023
Akdemir D, Somo M, Isidro-Sanchéz J.
europepmc   +1 more source

Long‐Tea‐CLIP: An Expert‐Level Multimodal AI Framework for Fine‐Grained Green Tea Grading Across Five Sensory Dimensions

Advanced Science, EarlyView.
Long‐Tea‐CLIP (Contrastive Language‐Image Pre‐training) presents a multimodal AI framework that integrates visual, metabolomic, and sensory knowledge to grade green tea across appearance, soup color, aroma, taste, and infused leaf. By combining expert‐guided modeling with CLIP‐supervised learning, the system delivers fine‐grained quality evaluation and
Yanqun Xu, Zhengfang Xue, Qing Luo, Xu Liu, Yongquan Xu, Huang Jing, Xingcai Zhang, Xinyuan Zhang, Zhonghua Liu, Zisheng Luo   +9 more
wiley   +1 more source

On Information Rank Deficiency in Phenotypic Covariance Matrices. [PDF]

Syst Biol, 2022
O'Keefe FR, Meachen JA, Polly PD.
europepmc   +1 more source

A Bottom‐Up Design Framework for Multifunctional Lattice Metamaterials

Advanced Science, EarlyView.
This study introduces a generative AI framework for designing multifunctional lattice metamaterials. The method combines 3D Gaussian voxel generation with deep learning, enabling greater design freedom and structural performance. The optimized lattice metamaterials achieve enhanced energy absorption by 40–200% compared to conventional structures and ...
Zongxin Hu, Quanqing Tao, Junhao Ding, Shuo Qu, Haitao Ye, Jun Wei Chua, Tianxiao Niu, Rui Li, Winston Wai Shing Ma, Haoming Mo, Hui Liu, Wei Zhai, Xinwei Li, Xu Song   +13 more
wiley   +1 more source

Shrinkage estimators of large covariance matrices with Toeplitz targets in array signal processing. [PDF]

Sci Rep, 2022
Zhang B, Yuan S.
europepmc   +1 more source

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

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, James Trevarthen, Igor Dolbnya, Wadwan Singhapong, Nicholas Pilato, Richard Butler, Jiraphant Srisuriyachot, Alexander J. G. Lunt   +7 more
wiley   +1 more source