Results 61 to 70 of about 112,001 (232)

Unbiased fully nonlinear data assimilation. Part 1: The stochastic particle flow filter

Quarterly Journal of the Royal Meteorological Society, EarlyView.
While the existing deterministic particle flow filter (PFF) has been applied successfully to nonlinear high‐dimensional systems, it tends to underestimate ensemble spread when using a small number of particles. We introduce the stochastic particle flow filter (SPFF), which incorporates an additional Gaussian noise term into the particle flow dynamics ...
Hao‐Lun Yeh, Peter Jan van Leeuwen
wiley   +1 more source

Norden structures of Hessian type

, 2014
In this paper, we show that Kahler (para-Kahler) manifolds admit a Norden-Hessian metric h = del(2) f if the function f is holomorphic (para-holomorphic), and we further consider the existence condition of para-Kahler structures for Norden-Hessian ...
SALIMOV, Arif, GEZER, Aydın, Gezer, Aydin   +2 more
core   +1 more source

Unbiased fully nonlinear data assimilation. Part 2: The stochastic particle flow smoother

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Building on the stochastic particle flow filter (SPFF) introduced in Part 1, we introduce a new smoother—the stochastic particle flow smoother (SPFS)—for high‐dimensional, nonlinear data assimilation. We examine two backward‐propagation strategies for the smoother, including an exact adjoint model, which allows particles to capture multimodal ...
Hao‐Lun Yeh, Peter Jan van Leeuwen
wiley   +1 more source

Zeroth-Order Riemannian Adaptive Regularized Proximal Quasi-Newton Optimization Method

Axioms
Recently, the adaptive regularized proximal quasi-Newton (ARPQN) method has demonstrated a strong performance in solving composite optimization problems over the Stiefel manifold.
Yinpu Ma, Cunlin Li, Zhichao Wang, Qian Li   +3 more
doaj   +1 more source

The Pontryagin Forms of Hessian Manifolds [PDF]

, 2016
We show that Hessian manifolds of dimensions 4 and above must have vanishing Pontryagin forms. This gives a topological obstruction to the existence of Hessian metrics. We find an additional explicit curvature identity for Hessian 4-manifolds. By contrast, we show that all analytic Riemannian 2-manifolds are Hessian.
Armstrong, J.; id_orcid 0000-0002-4232-9555, Amari, S.   +1 more
openaire  

Gradient‐ and Newton‐Based Unit Vector Extremum Seeking Control

International Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This paper proposes new methods for stable and efficient convergence in multivariable extremum seeking control (ESC) using sliding mode techniques. Inspired by classical sliding modes and finite‐time control, the approach integrates these ideas into gradient‐ and Newton‐based ESC schemes with sinusoidal perturbations.
Roberto Luo, Victor Hugo Pereira Rodrigues, Tiago Roux Oliveira, Miroslav Krstic   +3 more
wiley   +1 more source

Quasi-Kahler manifolds with trivial Chern holonomy [PDF]

, 2011
We study quasi-kahler manifolds with trivial Chern ...
Antonio J. Di Scala, Luigi Vezzoni, Vezzoni, L., Vezzoni, Luigi, Di Scala, Antonio Jose'   +4 more
core   +1 more source

Material Heterogeneity and Waste‐Trade Networks in EU‐27 Circular‐Economy Convergence

Sustainable Development, EarlyView.
ABSTRACT EU monitoring summarizes circular‐economy progress with aggregate indicators, although material‐specific adjustment and cross‐border secondary‐resource links may follow different paths. This study examines convergence across the EU‐27, heterogeneity among biomass, metal ores, non‐metallic minerals, and fossil‐energy materials, and network ...
Pan Jiang, Shuaiyi Lu, Lianghan Cong
wiley   +1 more source

An Optimal Transport Approach to Monge–Amp\ue8re Equations on Compact Hessian Manifolds [PDF]

, 2018
In this paper we consider Monge–Amp\ue8re equations on compact Hessian manifolds, or equivalently Monge–Amp\ue8re equations on certain unbounded convex domains in Euclidean space, with a periodicity constraint given by the action of an affine group.
Önnheim, Magnus, Hultgren, Jakob, 6nnheim, Magnus, Hultgren, Jakob,, Önnheim, Magnus,   +4 more
core   +1 more source

3D Reconstruction of Nanoparticle Distribution in Tumor Spheroids With Volume Electron Microscopy

Small, EarlyView.
Understanding where nanomaterials accumulate within cells is essential for revealing their biological fate and activity. We present a quantitative imaging framework to map nanomaterials and cellular structures in three dimensions. Applied to nanoparticle‐containing tumor spheroids, the approach reveals substantial cell‐to‐cell differences in uptake ...
Davide Bottone, Lukas R. H. Gerken, Sebastian Habermann, José María Mateos, Miriam S. Lucas, Johannes Riemann, Melanie Fachet, Ute Resch‐Genger, Vera M. Kissling, Matthias Rösslein, Alexander Gogos, Inge K. Herrmann   +11 more
wiley   +1 more source