Results 71 to 80 of about 1,656 (235)
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
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Quarterly Journal of the Royal Meteorological Society, EarlyView.An energy‐conserving discrete framework for the vertical discretisation of stratified ocean models is developed using internal gravity‐wave theory. A β$$ \beta $$‐indexed family of schemes is analysed through perturbation theory, revealing optimal parameter choices and grid designs that reduce truncation errors significantly.
Gabriel Derrida +3 more
wiley +1 more source
Quarterly Journal of the Royal Meteorological Society, EarlyView.Regional deep learning weather prediction (DLWP) models, such as Bris, offer high resolution forecasts comparable with traditional numerical weather prediction (NWP) models. We evaluated Bris against the operational MetCoOp Ensemble Prediction System (MEPS) during extratropical cyclone Poly (July 5, 2023).
Francesco Pasquini +4 more
wiley +1 more source
Some identities involving q-poly-tangent numbers and polynomials and distribution of their zeros
Advances in Difference Equations, 2017 In this paper we introduce the q-poly-tangent polynomials and numbers. We also give some properties, explicit formulas, several identities, a connection with poly-tangent numbers and polynomials, and some integral formulas.
CS Ryoo, RP Agarwal
doaj +1 more source
Optimal Gain Selection for the Arbitrary‐Order Homogeneous Differentiator
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT Differentiation of noisy signals is a relevant and challenging task. Widespread approaches are the linear high‐gain observer acting as a differentiator and Levant's robust exact differentiator with a discontinuous right‐hand side. We consider the family of arbitrary‐order homogeneous differentiators, which includes these special cases.
Benjamin Calmbach +2 more
wiley +1 more source
A Note on the 𝑞-Euler Numbers and Polynomials with Weak Weight 𝛼
Journal of Applied Mathematics, 2011 We construct a new type of 𝑞-Euler numbers and polynomials with weak weight 𝛼 : 𝐸(𝛼)𝑛,𝑞, 𝐸(𝛼)𝑛,𝑞(𝑥), respectively. Some interesting results and relationships are obtained.
H. Y. Lee, N. S. Jung, C. S. Ryoo
doaj +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
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, 2021 In this paper, we define a new form of Carlitz’s type degenerate twisted (p,q)-Euler numbers and polynomials by generalizing the degenerate Euler numbers and polynomials, Carlitz’s type degenerate q-Euler numbers and polynomials.
Cheon-Seoung Ryoo
core +1 more source
Exact Robust Filtering and Differentiation Based on Sliding Modes and Homogeneity
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT This article addresses the problem of online estimation of the derivatives of a signal corrupted by measurement noise. The measured signal is modeled as the sum of a smooth nominal component and a uniformly bounded noise term. A key objective is to attenuate the effect of high‐frequency noise.
Jaime A. Moreno, Arie Levant
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Spectral Submanifolds of Delay Systems: Control in Continuous and Discrete Time
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT This paper presents both continuous‐time and discretization‐based approaches for constructing spectral submanifolds (SSMs) for time delay systems. The continuous‐time approach built upon sun–star calculus, reformulates the governing delay differential equation (DDE) as an operator differential equation (OpDE).
Bence Szaksz +2 more
wiley +1 more source