Results 91 to 100 of about 108,134 (338)
Heuristically Adaptive Diffusion‐Model Evolutionary Strategy
Advanced Science, EarlyView.Building on the mathematical equivalence between diffusion models and evolutionary algorithms, researchers demonstrate unprecedented control over evolutionary optimization through conditional diffusion. By training diffusion models to associate parameters with specific traits, they can guide evolution toward solutions exhibiting desired behaviors ...
Benedikt Hartl +3 more
wiley +1 more source
Consistent Estimators of the Population Covariance Matrix and Its Reparameterizations
MathematicsFor 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
Statistica, 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
Improved estimation of the covariance matrix of stock returns with an application to portofolio selection [PDF]
This paper proposes to estimate the covariance matrix of stock returns by an optimally weighted average of two existing estimators: the sample covariance matrix and single-index covariance matrix.
Michael Wolf, Olivier Ledoit
core
Robust high-dimensional precision matrix estimation
, 2015 The dependency structure of multivariate data can be analyzed using the covariance matrix $\Sigma$. In many fields the precision matrix $\Sigma^{-1}$ is even more informative.
B. Bertsekas +24 more
core +1 more source
Consensus Formation and Change are Enhanced by Neutrality
Advanced Science, EarlyView.Neutral agents are shown to enhance both the formation and overturning of consensus in collective decision‐making. A general mathematical model and experiments with locusts and humans reveal that neutrality enables robust consensus via simple interactions and accelerates consensus change by reducing effective population size.
Andrei Sontag +3 more
wiley +1 more source
Selective Range Iterative Adaptive Approach for High-Resolution DOA Estimation
IEEE Access, 2019 In this paper, the problem of direction-of-arrival (DOA) estimation for a uniform linear array with single-snapshot observations is addressed. Two non-parametric DOA estimators are developed, which can be applied in any azimuth range with one snapshot ...
Yuan Chen +2 more
doaj +1 more source
"Selection of Variables in Multivariate Regression Models for Large Dimensions" [PDF]
The Akaike information criterion, AIC, and Mallows' Cp statistic have been proposed for selecting a smaller number of regressor variables in the multivariate regression models with fully unknown covariance matrix.
Muni S. Srivastava, Tatsuya Kubokawa
core
Stochastic Block Covariance Matrix Estimation
Motivated by a neuroscience application we study the problem of statistical estimation of a high-dimensional covariance matrix with a block structure. The block model embeds a structural assumption: the population of items (neurons) can be divided into latent sub-populations with shared associative covariation within blocks and shared associative or ...
Chen, Yunran +2 more
openaire +2 more sources
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