Results 81 to 90 of about 9,385 (270)

Preconditioning for active set and projected gradient methods as\ud semi-smooth Newton methods for PDE-constrained optimization\ud with control constraints [PDF]

, 2009
Optimal control problems with partial differential equations play an important role in many applications. The inclusion of bound constraints for the control poses a significant additional challenge for optimization methods.
Stoll, Martin, Wathen, A. J.
core   +1 more source

Block Locally Optimal Preconditioned Eigenvalue Xolvers (BLOPEX) in hypre and PETSc

, 2007
We describe our software package Block Locally Optimal Preconditioned Eigenvalue Xolvers (BLOPEX) publicly released recently. BLOPEX is available as a stand-alone serial library, as an external package to PETSc (``Portable, Extensible Toolkit for ...
Argentati, M.E., Argentati, M.E., Knyazev, A.V., Knyazev, A.V., Lashuk, I., Lashuk, I., Ovtchinnikov, E., Ovtchinnikov, E.   +7 more
core   +1 more source

Local Polynomial Regression and Filtering for a Versatile Mesh‐Free PDE Solver

International Journal for Numerical Methods in Fluids, EarlyView.
A high‐order, mesh‐free finite difference method for solving differential equations is presented. Both derivative approximation and scheme stabilisation is carried out by parametric or non‐parametric local polynomial regression, making the resulting numerical method accurate, simple and versatile. Numerous numerical benchmark tests are investigated for
Alberto M. Gambaruto
wiley   +1 more source

New preconditioners for stationary iterative methods

, 2020
75
openaire   +1 more source

Fast Calculation for the Flow and Heat Transfer of Tempered Fractional Maxwell Viscoelastic Fluid

International Journal for Numerical Methods in Fluids, EarlyView.
This study develops a tempered fractional Maxwell model to simulate unsteady thermal flow in viscoelastic fluids, capturing key rheological behaviors. A fast SOE‐based algorithm is proposed to improve the computational efficiency of the numerical scheme. Results reveal how key parameters influence fluid motion and heat transfer, demonstrating the model'
Yi Liu, Mochen Jiang, Libo Feng
wiley   +1 more source

Using constraint preconditioners with regularized saddle-point problems [PDF]

, 2005
The problem of finding good preconditioners for the numerical solution of a certain important class of indefinite linear systems is considered. These systems are of a 2 by 2 block (KKT) structure in which the (2,2) block (denoted by -C) is assumed to be ...
Dollar, H. Sue, Gould, Nicholas I. M., Schilders, W. H. A., Wathen, A. J.   +3 more
core   +2 more sources

New Generalised Semi‐Analytical Approach for the Multidimensional Nonlinear Collisional Fragmentation Equations

International Journal for Numerical Methods in Fluids, EarlyView.
This work aims to develop a generalised and efficient semi‐analytical method that combines the Laplace decomposition method with Pade approximation (LDMPA) to solve multidimensional nonlinear integro‐partial differential equation. For a one‐dimension case, explicit (closed‐form) solutions for the number density functions are derived for the first time.
Somveer Keshav, Ashok Das, Sukhjit Singh, Randhir Singh, Mehakpreet Singh   +4 more
wiley   +1 more source

Preconditioned progressive-iterative approximation for cubic B-spline fitting(三次B样条拟合的预处理渐进迭代逼近法)

Zhejiang Daxue xuebao. Lixue ban
To improve the convergence efficiency of progressive-iterative approximation for large-scale data fitting, we introduce a class of Jacobi preconditioners and develop two preconditioned methods: preconditioned LSPIA and preconditioned PmLSPIA.
LIU Chengzhi(刘成志), WU Nianci(吴念慈), LI Juncheng(李军成), HU Lijuan(胡丽娟)   +3 more
doaj   +1 more source

An Efficient Block Circulant Preconditioner For Simulating Fracture Using Large Fuse Networks

, 2005
{\it Critical slowing down} associated with the iterative solvers close to the critical point often hinders large-scale numerical simulation of fracture using discrete lattice networks.
Batrouni G G, Chakrabarti B K, Chan R, Chan R H, Chan R H, Chan T, de Arcangelis L, Duxbury P M, Golub G H, Hansen A, Herrmann H J, Nukala P K V V, Phani Kumar V V Nukala, Sahimi M, Srdan Simunovic, Tyrtyshnikov E   +15 more
core   +1 more source

Corticosterone and Mitochondrial Efficiency Are Associated With Changes in DNA Oxidative Damage During an Acute Stress Response in Leach's Storm‐Petrels (Hydrobates leucorhous)

Journal of Experimental Zoology Part A: Ecological and Integrative Physiology, EarlyView.
ABSTRACT The ability of organisms to effectively respond to challenges is critical for survival. We investigated how an acute stressor affected corticosterone, mitochondrial function, and DNA oxidative damage in a wild population of Leach's storm‐petrels (Hydrobates leucorhous).
Kayla E. Lichtner, Jack K. Dziubek, Nicole A. Joseph, Sarah E. Chapman, Tori J. Chace, Dongxiao Sun, Zachary T. Bitzer, Antoine Stier, Robert A. Mauck, Patricia L. Jones, Mark F. Haussmann   +10 more
wiley   +1 more source