Results 71 to 80 of about 4,516 (262)
Partial identification with categorical data and nonignorable missing outcomes
Canadian Journal of Statistics, EarlyView.Abstract Nonignorable missing outcomes are common in real‐world datasets and often require strong parametric assumptions to achieve identification. These assumptions can be implausible or untestable, and so we may wish to forgo them in favour of partially identified models that narrow the set of a priori possible values to an identification region.
Daniel Daly‐Grafstein, Paul Gustafson
wiley +1 more source
Canadian Journal of Statistics, EarlyView.Abstract Homogeneous normalized random measures with independent increments represent a broad class of Bayesian nonparametric priors and thus are widely used. In this article, we obtain the strong law of large numbers, the central limit theorem (CLT), and the functional central limit theorem (fCLT) of such measures when the concentration parameter a ...
Junxi Zhang, Shui Feng, Yaozhong Hu
wiley +1 more source
Symmetry theorems via the continuous steiner symmetrization
Electronic Journal of Differential Equations, 2000 Using a new approach due to F. Brock called the Steiner symmetrization, we show first that if $u$ is a solution of an overdetermined problem in the divergence form satisfying the Neumann and non-constant Dirichlet boundary conditions, then $Omega$ is an ...
L. Ragoub
doaj
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 +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
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Coupling Fluid Neutrals to Gyrokinetic Plasma Dynamics for Edge and SOL Turbulence Simulations
Contributions to Plasma Physics, EarlyView.ABSTRACT Accurate modeling of turbulent transport in magnetic confinement fusion devices requires extending first‐principles gyrokinetic simulations from the core to the edge and scrape‐off layer (SOL), where additional physics—particularly plasma–neutrals interactions—must be included.
Sabine Ogier‐Collin +3 more
wiley +1 more source
Edge Fluid Turbulence Simulations of Stellarators With GRILLIX
Contributions to Plasma Physics, EarlyView.ABSTRACT The edge fluid turbulence code GRILLIX has recently been extended from axisymmetric tokamak geometries to support 3D stellarator configurations. Following successful proof‐of‐principle simulations published in Stegmeir et al., we present here a comprehensive simulation of the Wendelstein 7‐AS stellarator.
Andreas Stegmeir +4 more
wiley +1 more source
The Nehari Manifold for p-Laplacian Equation with Dirichlet Boundary Condition
Nonlinear Analysis, 2007 The Nehari manifold for the equation −∆pu(x) = λu(x)|u(x)| p−2 + b(x)|u(x)| γ−2u(x) for x ∈ Ω together with Dirichlet boundary condition is investigated in the case where 0 < γ < p.
G. A. Afrouzi, S. Mahdavi, Z. Naghizadeh
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Towards a Mean‐Field Braginskii Model for Stellarators
Contributions to Plasma Physics, EarlyView.ABSTRACT Experiments in the stellarator Wendelstein 7‐X indicate that particle drifts have a significant impact on the plasma in the scrape‐off layer. However, drift effects have been absent in the mean‐field transport codes such as EMC3‐Eirene. For this reason, we present the first steps towards a mean‐field model that incorporates drifts. The code is
T. Tork +7 more
wiley +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 +2 more
wiley +1 more source