Results 201 to 210 of about 140,463 (248)
Supervised Protein Structure Classification Using Topological Persistence With DeltaFold
Proteins: Structure, Function, and Bioinformatics, EarlyView.ABSTRACT Recent advances in protein structure prediction have considerably increased the number of available structures, underscoring the need for scalable and accurate methods to compare and classify this huge amount of data. Current approaches based on sequence alignment or structural superposition often lack sensitivity and/or are computationally ...
Joseph Nardin‐Gennequin +3 more
wiley +1 more source
New views of some invariants associated with the Cartesian 2D velocity gradient tensor
Quarterly Journal of the Royal Meteorological Society, EarlyView.Vorticity and divergence of horizontal flow are fundamental quantities in meteorology; both are linear functions of the four elements of the 2D velocity gradient tensor and both are formally unchanged under coordinate rotation. We explore four quadratic functions of the elements that are geometrically invariant in this sense, finding some novel ...
I. Roulstone, S. A. Clough, A. A. White
wiley +1 more source
Low‐order system for eddy growth in the storm track
Quarterly Journal of the Royal Meteorological Society, EarlyView.Reanalysis data for the North Atlantic storm track are used to construct a low‐order model that optimally fits the observed interaction between the mean flow and baroclinic eddies. The resulting model is a certain type of predator–prey model. It explains various properties of the storm track, including why eddies grow linearly with the Eady growth rate,
Maarten H. P. Ambaum, Thomas H. A. Frame
wiley +1 more source
Data‐driven emulation of flow‐dependent background‐error variance in variational data assimilation
Quarterly Journal of the Royal Meteorological Society, EarlyView.A machine‐learning approach is developed to emulate flow‐dependent background‐error variance within a variational data assimilation framework. The method reproduces uncertainty information that would normally require a 50‐member ensemble using only five members, while maintaining comparable observation fit and forecast performance.
Wei Pan +3 more
wiley +1 more source
Optimal Homogeneous ℒp$$ {\boldsymbol{\mathcal{L}}}_{\boldsymbol{p}} $$‐Gain Controller
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT Nonlinear ℋ∞$$ {\mathscr{H}}_{\infty } $$‐controllers are designed for arbitrarily weighted, continuous homogeneous systems with a focus on systems affine in the control input. Based on the homogeneous ℒp$$ {\mathcal{L}}_p $$‐norm, the input–output behavior is quantified in terms of the homogeneous ℒp$$ {\mathcal{L}}_p $$‐gain as a ...
Daipeng Zhang +3 more
wiley +1 more source
Sliding Mode Control in Aerospace Applications: A Survey
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT Sliding mode control (SMC) enjoys robustness to matched and unmatched (in the case of minimum phase input‐output dynamics) bounded perturbations, and finite time convergence. Second‐order and higher‐order sliding mode control systems (2‐SMC/HOSMC) retain all the advantages of sliding mode control, but in addition can be applied to systems of ...
Yuri Shtessel, Christopher Edwards
wiley +1 more source
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT This paper establishes an implementation‐aware framework for Barrier Function Adaptation (BFA) and shows that discrete‐time realizations fundamentally alter the logic of final‐set adjustment. In particular, sufficient conditions are derived to preserve the key benefits of BFA (predefined performance, gain adaptation with uncertain perturbation
Luis Ovalle +3 more
wiley +1 more source
Sliding Motions on Non‐Euclidean State Spaces: A Differential‐Geometric Perspective
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT This paper extends sliding‐mode control theory to nonlinear systems evolving on smooth manifolds. Building on differential geometric methods, we reformulate Filippov's notion of solutions, characterize well‐defined vector fields on quotient spaces, and provide a consistent geometric definition of higher‐order sliding modes.
Fernando Castaños
wiley +1 more source