Results 121 to 130 of about 16,710 (257)

An Algorithm for Computing Geometric Mean of Two Hermitian Positive Definite Matrices via Matrix Sign

open access: yesAbstract and Applied Analysis, 2014
Using the relation between a principal matrix square root and its inverse with the geometric mean, we present a fast algorithm for computing the geometric mean of two Hermitian positive definite matrices.
F. Soleymani   +3 more
doaj   +1 more source

A partial envelope approach for modelling multivariate spatial‐temporal data

open access: yesCanadian Journal of Statistics, EarlyView.
Abstract In the new era of big data, modelling multivariate spatial‐temporal data is a challenging task due to both the high dimensionality of the features and complex associations among the responses across different locations and time points.
Reisa Widjaja   +3 more
wiley   +1 more source

Dynamic survival risk prediction with time‐varying high‐dimensional images

open access: yesCanadian Journal of Statistics, EarlyView.
Abstract Integrating longitudinal data with survival models is a prevalent strategy for dynamic survival risk prediction while accounting for subjects' longitudinally observed variables. However, existing methods primarily focus on scalar longitudinal data and seldom tackle the complexities associated with high‐dimensional longitudinal imaging data ...
Bingfan Liu   +7 more
wiley   +1 more source

Aggregating distributed energy resources for grid flexibility services: A distributed game theoretic approach

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView., 2023
Abstract We propose a hierarchical energy management scheme for aggregating Distributed Energy Resources (DERs) for grid flexibility services. To prevent a direct participation of numerous prosumers in the wholesale electricity market, aggregators, as self‐interest agents in our scheme, incentivize prosumers to provide flexibility. We firstly model the
Xiupeng Chen   +3 more
wiley   +1 more source

Pdmatrix" -- Progams To Make Matrices Positive Definite [PDF]

open access: yes, 2007
INTRODUCTION Quantitative genetic theory for continuous traits under the infinitesimal model assumes a multivariate normal distribution with positive (semi-) definite covariance matrix. In estimating such matrices, however, we frequently obtain matrices
Karin Meyer   +2 more
core  

Nonlinear permuted Granger causality

open access: yesCanadian Journal of Statistics, EarlyView.
Abstract Granger causality is an established, contentious method that seeks causal temporal connections via association and precedence. While not true causal inference, it assists in mapping networks of information flow that may warrant further study.
Noah D. Gade, Jordan Rodu
wiley   +1 more source

Positive Sub-Definite Matrices Over a Proper Cone Completeness of Rank One Matrix [PDF]

open access: yes, 2014
The purpose of this paper is to check rank one matrix thoroughly and identify the existence of positive sub-definite matrices, generalize positive sub-definite matrices, weakly generalized positive sub-definite matrices and copositive matrices on it ...
Tanjena S. Khan, A. Hassouni, A. Lahlou
core  

Stochastic Gradient Descent in High Dimensions for Multi‐Spiked Tensor PCA

open access: yesCommunications on Pure and Applied Mathematics, EarlyView.
ABSTRACT We study the high‐dimensional dynamics of online stochastic gradient descent (SGD) for the multi‐spiked tensor model. This multi‐index model arises from the tensor principal component analysis (PCA) problem with multiple spikes, where the goal is to estimate the unknown signal vectors within the N$N$‐dimensional unit sphere through maximum ...
Gérard Ben Arous   +2 more
wiley   +1 more source

The in‐hospital administration of sacubitril/valsartan in acute myocardial infarction: A meta‐analysis

open access: yesESC Heart Failure, Volume 12, Issue 2, Page 998-1012, April 2025.
In patients with Acute Myocardial Infarction related heart failure, the in‐hospital administration of ARNIs was associated with a reduced risk of MACEs and re‐hospitalizations for heart failure, as well as cardiac remodeling, compared to standard therapy.
Gianluca Di Pietro   +15 more
wiley   +1 more source

Concept, Tests, and Optimum Design of Novel Negative Stiffness Friction Dampers for Seismic Protection of Long‐Span Bridges

open access: yesEarthquake Engineering &Structural Dynamics, EarlyView.
ABSTRACT Viscous dampers (VDs) are widely used to mitigate the excessive responses of long‐span bridges. However, VDs face some intricate challenges in engineering practices, including high damping coefficient requirement, potential base shear amplification and tremendous damping force under high velocity. To address these issues, this study develops a
Ruisheng Ma   +5 more
wiley   +1 more source

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