Results 31 to 40 of about 641 (184)

A Flexible Extended Krylov Subspace Method for Approximating Markov Functions of Matrices

Mathematics, 2023
A flexible extended Krylov subspace method (F-EKSM) is considered for numerical approximation of the action of a matrix function f(A) to a vector b, where the function f is of Markov type.
Shengjie Xu, Fei Xue
doaj   +1 more source

Sparse Regularization Least-Squares Reverse Time Migration Based on the Krylov Subspace Method

Remote Sensing
Least-squares reverse time migration (LSRTM) is an advanced seismic imaging technique that reconstructs subsurface models by minimizing the residuals between simulated and observed data. Mathematically, the LSRTM inversion of the sub-surface reflectivity
Guangshuai Peng, Xiangbo Gong, Shuang Wang, Zhiyu Cao, Zhuo Xu   +4 more
doaj   +1 more source

A structurally localized ensemble Kalman filtering approach

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We derive an inherently localized ensemble Kalman filtering (EnKF) approach, avoiding the need for any auxiliary localization technique. The idea is to first use the variational Bayesian optimization to approximate the (continuous) state analysis probability density function (pdf) by a product of independent marginal pdfs corresponding to small ...
Boujemaa Ait‐El‐Fquih, Ibrahim Hoteit   +1 more
wiley   +1 more source

A Preconditioned Policy–Krylov Subspace Method for Fractional Partial Integro-Differential HJB Equations in Finance

Fractal and Fractional
To better simulate the prices of underlying assets and improve the accuracy of pricing financial derivatives, an increasing number of new models are being proposed.
Xu Chen, Xin-Xin Gong, Youfa Sun, Siu-Long Lei   +3 more
doaj   +1 more source

An Improved Fast Computational Method for Vibration Characteristic Analysis of Dry‐Type Iron Core Reactor

High Voltage, EarlyView.
ABSTRACT Structural mechanics field simulation plays a critical role in the vibration characteristic analysis of electrical equipment. Existing structural field analysis of equipment based on numerical simulation faces challenges such as convergence difficulties and prolonged computational time, failing to meet the demand for real‐time prediction of ...
Wanqing Wang, Caibo Liao, Bang Liu, Kai Li, Wenyu Liu, Zhaoguo Li, Xianfa Tian   +6 more
wiley   +1 more source

New Preconditioned Iteration Method Solving the Special Linear System from the PDE-Constrained Optimal Control Problem

Mathematics, 2021
In many fields of science and engineering, partial differential equation (PDE) constrained optimal control problems are widely used. We mainly solve the optimization problem constrained by the time-periodic eddy current equation in this paper. We propose
Yan-Ran Li, Xin-Hui Shao, Shi-Yu Li
doaj   +1 more source

Solid Mechanics Segregated Solver Acceleration With Jacobian‐Free Newton‐Krylov

International Journal for Numerical Methods in Engineering, Volume 127, Issue 11, 15 June 2026.
ABSTRACT The segregated algorithm is a common approach for finite volumes solvers in solid mechanics, providing a memory‐efficient and straightforward implementation. Due to the inter‐coupling of the components through the source terms, it suffers from a slow convergence behavior in specific scenarios, such as geometries with significantly uneven ...
Andry Monlon, Alessandro Scolaro, Philip Cardiff, Ivor Clifford, Oskari Pakari, Mathieu Hursin   +5 more
wiley   +1 more source

Stochastic estimation of nuclear level density in the nuclear shell model: An application to parity-dependent level density in 58Ni

Physics Letters B, 2016
We introduce a novel method to obtain level densities in large-scale shell-model calculations. Our method is a stochastic estimation of eigenvalue count based on a shifted Krylov-subspace method, which enables us to obtain level densities of huge ...
Noritaka Shimizu, Yutaka Utsuno, Yasunori Futamura, Tetsuya Sakurai, Takahiro Mizusaki, Takaharu Otsuka   +5 more
doaj   +1 more source

Coupled Clustering in Hierarchical Matrices for the Oseen Problem

International Journal for Numerical Methods in Fluids, Volume 98, Issue 6, Page 751-765, June 2026.
Fluid flow problems can be modelled by the Navier‐Stokes or, after linearization, by the Oseen equations. Their discretization results in linear systems in saddle point form which are typically very large and need to be solved iteratively. We propose a novel block structure for hierarchical matrices which is then used to build preconditioners for the ...
Jonas Grams, Sabine Le Borne
wiley   +1 more source

On Some Numerical Methods for Solving Large Differential Nonsymmetric Stein Matrix Equations

Mathematical and Computational Applications, 2022
In this paper, we propose a new numerical method based on the extended block Arnoldi algorithm for solving large-scale differential nonsymmetric Stein matrix equations with low-rank right-hand sides.
Lakhlifa Sadek, El Mostafa Sadek, Hamad Talibi Alaoui   +2 more
doaj   +1 more source