Results 31 to 40 of about 688 (217)
Stochastic Gradient Descent in High Dimensions for Multi‐Spiked Tensor PCA
Communications 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
Compact Manifolds With Unbounded Nilpotent Fundamental Groups and Positive Ricci Curvature
Communications on Pure and Applied Mathematics, EarlyView.ABSTRACT It follows from the work of Kapovitch and Wilking that a closed manifold with nonnegative Ricci curvature has a uniformly almost nilpotent fundamental group. Leftover questions and conjectures, have asked if in this context the fundamental group is actually uniformly almost abelian. The main goal of this work is to construct examples (Mk9,gk)$(
Elia Bruè, Aaron Naber, Daniele Semola
wiley +1 more source
Kinetic Contribution to the Arbitrary Order Odd Frequency Moments of the Dynamic Structure Factor
Contributions to Plasma Physics, EarlyView.ABSTRACT An exact expression is derived for the kinetic contribution to the odd (arbitrary order) frequency moments of the dynamic structure factor via a finite summation that features averages of even (all lower orders) powers of the momentum over the exact momentum distribution.
Panagiotis Tolias +2 more
wiley +1 more source
Review and prospects of shear test of bolted rock joints
Deep Underground Science and Engineering, EarlyView.The laboratory shear test equipment, test method, and numerical simulation of bolted rock joints were summarized. The shortcomings and limitations of the current research were analyzed, and the research prospects were proposed. Abstract Rock bolting is a critical approach in geotechnical engineering for supporting weak rocks.
Shulin Ren +4 more
wiley +1 more source
ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.A physics‐informed machine learning approach successfully decodes the complex catalytic activity of high‐entropy alloys for ammonia oxidation. By revealing a synergistic mechanism involving lattice and electronic couplings, the study identifies a superior “isolated‐surrounded” platinum motif.
Shangfeng Jiang +5 more
wiley +1 more source
International Journal for Numerical Methods in Fluids, EarlyView.This article provides important geometric formulas for node‐centered, edge‐based schemes in any number of dimensions. These formulas are noteworthy, as they do not require the explicit formation of dual regions. We prove several key geometric results, with a particular focus on the four‐dimensional case, due to potential space‐time applications ...
Nicholas Tufillaro +2 more
wiley +1 more source
Subspace Acceleration for Efficient Nonlinear Water Wave Simulation
International Journal for Numerical Methods in Fluids, EarlyView.We introduce an exponentially weighted subspace acceleration technique to reduce GMRES iterations for solving the Poisson equation with time‐dependent coefficients in nonlinear, dispersive free‐surface flows governed by the incompressible Navier‐Stokes equations. The method significantly reduces memory requirements and computational complexity compared
Rasmus Kleist Hørlyck Sørensen +3 more
wiley +1 more source
International Journal for Numerical Methods in Fluids, EarlyView.Employing the moving least‐squares aided finite element method (MLS‐FEM) allows detailed thermal analysis in complex porous structures, such as polymeric foams, where the conductive heat transfer mechanism governs in the solid matrix and the convective mechanism dominates within the gas‐filled voids.
Mehdi Mostafaiyan +2 more
wiley +1 more source
Immersed Boundary Projection Method for Boundaries With Slip Velocities
International Journal for Numerical Methods in Fluids, EarlyView.A formulation of the immersed boundary method for incompressible flow over arbitrarily‐shaped bodies with surface slip described by the Navier boundary condition is presented. The wall slip velocity and the boundary force are determined implicitly through a projection to satisfy both the boundary condition and the divergence‐free condition of the ...
Takehiro Fujii, Takeshi Omori
wiley +1 more source
A Multi‐Objective Periodic Vehicle Routing Model for Sustainable Healthcare Waste Collection
The International Journal of Health Planning and Management, EarlyView.ABSTRACT The collection of infectious waste from healthcare facilities (HCF) constitutes a recurring operational challenge. Indeed, despite the inherent health risks posed by the storage and the transportation of infectious materials, most of the existing waste collection systems tends to prioritise cost optimization and to underaddress the safety ...
Hajer Ben‐Romdhane
wiley +1 more source