Results 91 to 100 of about 17,645 (222)
The c-numerical range of tridiagonal matrices
Linear Algebra and its Applications, 2001 The authors give several conditions for the \(c\)-numerical range \(W_c(A)\) of a tridiagonal matrix \(A\in M_n({\mathbb C})\) with \(0\) main diagonal to be an elliptic disc; \(W_c(A)=\{\sum c_jx_j^*Ax_j\): \(\{x_1,x_2,\dots,x_n\}\) is an orthonormal basis of~\({\mathbb C}^n\}\).
Chien, Mao-Ting, Nakazato, Hiroshi
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Quarterly Journal of the Royal Meteorological Society, Volume 151, Issue 772, October 2025 Part A.We study the impact of observation‐error correlations in data assimilation using both a simple idealised system and a more realistic configuration. A spectral analysis of data assimilation in the idealised system allows us to gain insights on the effect of observation‐error correlations, which are then validated using the realistic configuration.
Olivier Goux +4 more
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Journal of Advances in Modeling Earth Systems, Volume 17, Issue 10, October 2025.Abstract Global numerical modeling is advancing into the era of kilometer‐scale, non‐hydrostatic simulations, while heterogeneous computing emerges as a pivotal trend in high‐performance computing (HPC). As a strong candidate for next‐generation global kilometer‐scale general circulation models, the A‐grid dynamical core based on the Low Mach number ...
Weikang Zhang, Xi Chen
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Perturbation bounds of eigenvalues of Hermitian matrices with block structures
, 2010 We derive new perturbation bounds for eigenvalues of Hermitian matrices with block structures. The structures we consider range from a standard 2-by-2 block form to block tridiagonal and tridigaonal forms.
Nakatsukasa, Yuji
core
Inversion of tridiagonal matrices
Numerische Mathematik, 1982 This paper presents a simple algorithm for inverting nonsymmetric tridiagonal matrices that leads immediately to closed forms when they exist. Ukita's theorem is extended to characterize the class of matrices that have tridiagonal inverses.
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Journal of Advances in Modeling Earth Systems, Volume 17, Issue 10, October 2025.Abstract Simulation of turbulence in the atmospheric boundary layer (ABL) is challenging due to the wide range of turbulent scales in the flow. To leverage the currently available computational power for high‐resolution simulation of atmospheric turbulence, fluid solvers that scale well on large compute clusters are required.
L. Huusko +5 more
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Resolving Inhomogeneous Cloud Microphysics Through Cloud‐Top Observations of Blue Corona Discharges
Geophysical Research Letters, Volume 52, Issue 17, 16 September 2025.Abstract Understanding cloud‐top microphysics is essential for improving weather forecasting and convection monitoring. In this study, we propose a simplified cloud scattering light model to analyze the influence of inhomogeneities in the cloud microphysical properties on the observations of blue corona discharges (BLUEs) from Atmosphere‐Space ...
Dongshuai Li +7 more
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$\\mathcal O(n)$ working precision inverses for symmetric tridiagonal\n Toeplitz matrices with $\\mathcal O(1)$ floating point calculations [PDF]
, 2016 Manuel Radons
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GeoHealth, Volume 9, Issue 9, September 2025.Abstract Most of the United States (US) population resides in cities, where they are subjected to the urban heat island effect. In this study, we develop a method to estimate hourly air temperatures at 0.01°×0.01° $0.01{}^{\circ}\times 0.01{}^{\circ}$ resolution, improving exposure assessment of US population when compared to existing gridded products.
Eva Marquès, Kyle P. Messier
wiley +1 more source
New norm equalities and inequalities for operator matrices
Journal of Inequalities and Applications, 2016 We prove new inequalities for general 2 × 2 $2\times2$ operator matrices. These inequalities, which are based on classical convexity inequalities, generalize earlier inequalities for sums of operators. Some other related results are also presented. Also,
Feras Ali Bani-Ahmad, Watheq Bani-Domi
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