Results 91 to 100 of about 3,430 (271)

Power spectral density and the brain

Canadian Journal of Statistics, EarlyView.
Abstract Time series from M/EEG (magneto/electroencephalography) and ECoG (electrocorticography) recordings are common sources of information about brain function. The power spectral density (PSD) preserves much of this information, up to second order. In the current decade, a burst of brain diagnostics using the slope of log(PSD) has appeared.
Priscilla E. Greenwood, Sveinung Erland, Lawrence M. Ward   +2 more
wiley   +1 more source

Front Propagation Through a Perforated Wall

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT We consider a bistable reaction– diffusion equation ut=Δu+f(u)$u_t=\Delta u +f(u)$ on RN${\mathbb {R}}^N$ in the presence of an obstacle K$K$, which is a wall of infinite span with many holes. More precisely, K$K$ is a closed subset of RN${\mathbb {R}}^N$ with smooth boundary such that its projection onto the x1$x_1$‐axis is bounded and that ...
Henri Berestycki, François Hamel, Hiroshi Matano   +2 more
wiley   +1 more source

A Geometric Characterization of Steady Laminar Flow

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT We study the steady states of the Euler equations on the periodic channel or annulus. We show that if these flows are laminar (layered by closed non‐contractible streamlines which foliate the domain), then they must be either parallel or circular flows.
Theodore D. Drivas, Marc Nualart
wiley   +1 more source

Convergence results for piecewise linear quadratures for Cauchy principal value integrals [PDF]

, 1988
Conditions on k and f are given for the pointwise and uniform convergence to the Cauchy principal value integral \[ ∫ k ( x ) f (
Philip Rabinowitz
core   +1 more source

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, Cédric Gerbelot, Vanessa Piccolo   +2 more
wiley   +1 more source

Noninterpolatory integration rules for Cauchy principal value integrals [PDF]

, 1989
Let w ( x ) w(x) be an admissible weight on [ − 1 , 1 ] [ - 1,1] and let { p n
P. Rabinowitz, D. S. Lubinsky
core   +1 more source

Modeling proppant transport and settling in a 3D propagating fracture

Deep Underground Science and Engineering, EarlyView.
A versatile multiphysics tool is presented for simulating the complex processes involved in hydraulic fracturing treatments. The model couples fracture opening and propagation, variable‐density slurry flow, and proppant particle transport within the multiphysics object‐oriented simulation environment framework, based on two‐phase mixture equations and ...
Robert Egert, Aimé Fournier, Wencheng Jin   +2 more
wiley   +1 more source

Boundary behavior and estimates for solutions of equations containing the $p$-laplacian

Electronic Journal of Differential Equations, 1999
We use ``Hardy-type'' inequalities to derive $L^q$ estimates for solutions of equations containing the $p$-Laplacian with $p>1$. We begin by deriving some inequalities using elementary ideas from an early article [B3] which has been largely overlooked ...
Jacqueline Fleckinger, Evans M. Harrell II, Francois De Thelin   +2 more
doaj  

Cobalt Single‐Atom Sites Engineered in Poly(Heptazine Imide) Photocathodes as Benchmark for Alkaline Hydrogen Evolution: A Comparative Transition Metal Study

ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Cobalt single‐atoms in poly(heptazine imide) photocathodes maximize active‐site availability and outperform Fe, Cu, and Na in alkaline hydrogen evolution. Atomic precision (not bulk loading) proves predominance, establishing a design principle for the next generation of solar fuel devices.
Izadora F. Reis, Gabriel A. A. Diab, Sachin Nenaniya, Marcos A. R. da Silva, Rayse M. Ferreira, Heer Shah, Geraldo M. G. da Silva, Andreas Hutzler, Mark Isaacs, Christian W. Lopes, Ivo F. Teixeira, Pablo Jiménez‐Calvo   +11 more
wiley   +1 more source

Stability Evaluation and Parametric Optimization of Coal‐Concrete Composite Bearing Systems Under Mine‐Water‐Induced Deterioration: Experiments and FEINN Analysis

Energy Science &Engineering, EarlyView.
Mine‐water immersion tests reveal pronounced coal weakening (vs. minor concrete degradation), identifying coal pillars as the stability‐limiting component in composite dams. A coupled FEINN framework quantifies extreme‐pressure stability and ranks multi‐parameter designs via a normalized multi‐indicator scheme, enabling optimized dam configuration for ...
He Wen, Hongchuan Dai, Guixin Zhang, Pengzhe Li, Tong Yang, Cang Gong, Renbo Gao   +6 more
wiley   +1 more source