Results 131 to 140 of about 403 (256)

Ensemble reliability and the signal‐to‐noise paradox in ECMWF subseasonal forecasts

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We derive a general expression for the ratio of predictable components (RPC) in terms of correlation, spread–error ratio, and total variance ratio. Physical constraints on the admissible solutions (i.e., real‐valued and non‐negative variances) provide a mechanism to identify statistically paradoxical sample combinations of reliability and correlation ...
Christopher D. Roberts, Frederic Vitart
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

Emerging trends in soft set theory and related topics. [PDF]

ScientificWorldJournal, 2015
Feng F, Cagman N, Leoreanu-Fotea V, Akram M.   +3 more
europepmc   +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, Benjamin Calmbach, Jaime A. Moreno, Johann Reger   +3 more
wiley   +1 more source

Quadratic Subproduct Systems, Free Products, and Their C*-Algebras. [PDF]

Integr Equ Oper Theory
Arici F, Ge Y.
europepmc   +1 more source

(Fuzzy) Ideals of BN-Algebras. [PDF]

ScientificWorldJournal, 2015
Dymek G, Walendziak A.
europepmc   +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

Group Structures and Derivations on  <i>PMS</i>-algebras. [PDF]

F1000Res
Melese Kassahun N, Assaye Alaba B, Gedamu Wondifraw Y, Teshome Wale Z.   +3 more
europepmc   +1 more source

The role of identification in data‐driven policy iteration: A system theoretic study

International Journal of Robust and Nonlinear Control, EarlyView.
Abstract The goal of this article is to study fundamental mechanisms behind so‐called indirect and direct data‐driven control for unknown systems. Specifically, we consider policy iteration applied to the linear quadratic regulator problem. Two iterative procedures, where data collected from the system are repeatedly used to compute new estimates of ...
Bowen Song, Andrea Iannelli
wiley   +1 more source

On <i>t</i>-derivations of PMS-algebras. [PDF]

F1000Res
Melese Kassahun N, Assaye Alaba B, Gedamu Wondifraw Y, Teshome Wale Z.   +3 more
europepmc   +1 more source