Results 121 to 130 of about 1,227,664 (287)
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
On analysis error covariances in variational data assimilation [PDF]
, 2008 The problem of variational data assimilation for a nonlinear evolution model is formulated as an optimal control problem to find the initial condition function (analysis).
Shutyaev, V. +2 more
core +2 more sources
On the Second Boundary Value Problem for a Class of Modified-Hessian Equations
, 2016 In this paper a new class of modified-Hessian equations, closely related to the Optimal Transportation Equation, will be introduced and studied. In particular, the existence of globally smooth, classical solutions of these equations satisfying the ...
Von Nessi, Gregory
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
The continuous subsolution problem for complex Hessian equations
Indiana University Mathematics JournalThis is the final version accepted for publication in IUMJ.
Charabati, Mohamad, Zeriahi, Ahmed
openaire +3 more sources
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 +3 more
wiley +1 more source
Two-Dimensional Einstein Manifolds in Geometrothermodynamics
Advances in High Energy Physics, 2013 We present a class of thermodynamic systems with constant thermodynamic curvature which, within the context of geometric approaches of thermodynamics, can be interpreted as constant thermodynamic interaction among their components.
Antonio C. Gutiérrez-Piñeres +2 more
doaj +1 more source
On the Symmetry of Solutions to a k-Hessian Type Equation
Advanced Nonlinear Studies, 2013 Abstract In this note we prove that if u is a negative solution to a nonlinear elliptic equation involving a Hessian operator, and u is zero on the boundary of a ball, then u is radially symmetric and increasing along the radii.
openaire +4 more sources
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
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 +11 more
wiley +1 more source