Results 51 to 60 of about 1,275 (248)

Nonsymmetric multigrid preconditioning for conjugate gradient methods

, 2012
We numerically analyze the possibility of turning off post-smoothing (relaxation) in geometric multigrid when used as a preconditioner in conjugate gradient linear and eigenvalue solvers for the 3D Laplacian. The geometric Semicoarsening Multigrid (SMG) method is provided by the hypre parallel software package.
Bouwmeester, Henricus, Dougherty, Andrew, Knyazev, Andrew V.   +2 more
openaire   +2 more sources

Flexible Chemiresistive Chitosan‐Glycerol Sensors on Laser‐Induced Graphene Electrodes for Room‐Temperature Ammonia Detection

Advanced Materials Technologies, EarlyView.
Flexible Chitosan‐glycerol sensor integrated with porous laser‐induced graphene (LIG) electrodes enable room‐temperature chemiresistive detection of ammonia (NH3) and proof‐of‐concept detection of fish spoilage. ABSTRACT We report a metal‐free sensor platform combining laser induced graphene (LIG) electrodes with drop‐deposited, glycerol‐plasticized ...
Mintesinot Tamiru Mengistu, Richard Murray, Cara‐Lena Nies, Cathal Larrigy, Martina Piletti, Jahidul Islam, Daniela Iacopino, Eileen Hurley, Michael Nolan, Aidan J. Quinn   +9 more
wiley   +1 more source

Conjugate-gradient preconditioning methods for shift-variant PET image reconstruction [PDF]

IEEE Transactions on Image Processing, 1999
Gradient-based iterative methods often converge slowly for tomographic image reconstruction and image restoration problems, but can be accelerated by suitable preconditioners. Diagonal preconditioners offer some improvement in convergence rate, but do not incorporate the structure of the Hessian matrices in imaging problems.
Fessler, Jeffrey A., Booth, Scott D.
openaire   +4 more sources

Endogenous “Time Bomb” – Mislocalized Phospholipase A2 as a Critical Mediator of Ultra‐Rapid Mortality in Sepsis and Acute Lung Injury

Advanced Science, EarlyView.
Phospholipase A2 (PLA2), a dormant enzyme, becomes lethal when activated—collapsing lungs in minutes. Our dual therapy (DOPS + varespladib) boosts survival from 0% to >90% in sepsis/ALI. A breakthrough for acute lung injury treatment. ABSTRACT This study reveals that phospholipase A2 (PLA2), normally stable and nontoxic, can be activated specifically ...
Jianyu Wang, Zhongxing Xu, Lin Wang, Xin Sui, Yuan Luo, Xiuli Zhao, Jun Yang, Yongan Wang   +7 more
wiley   +1 more source

The Numerical Solution of Singularly Perturbed Nonlinear Partial Differential Equations in Three Space Variables: The Adaptive Explicit Inverse Preconditioning Approach

Modelling and Simulation in Engineering, 2019
Critical comments on the complexity of computational systems and the basic singularly perturbed (SP) concepts are given. A class of several complex SP nonlinear elliptic equations arising in various branches of science, technology, and engineering is ...
Anastasia-Dimitra Lipitakis
doaj   +1 more source

Spatial‐Wavelength Multiplexing Error‐Controlled Photonic Analog Computing System

Advanced Science, EarlyView.
A novel photonic integrated circuit prototype implementing the concept of general‐purpose analog computing and demonstrate its capability in radio frequency applications. The chip features a multichannel architecture and performs fully optical analog computation with frequency‐domain parallel processing. An FPGA‐based error‐correction algorithm aims to
Tao Zhu, Bowen Zhu, Shicheng Zhang, Keren Li, Xianchen Wu, Yazhi Pi, Jie Yan, Daigao Chen, Bingli Guo, Xi Xiao, Lei Wang, Xiaochuan Xu, Xuwei Xue, Shanguo Huang, Zizheng Cao, Shaohua Yu   +15 more
wiley   +1 more source

Application of Exact Newton Optimisation to the Maximum Likelihood Ensemble Filter

Tellus: Series A, Dynamic Meteorology and Oceanography
The Newton method is used for optimisation in the maximum likelihood ensemble filter (MLEF) to improve analysis convergence and accuracy. The proposed method is compared against the original method using the conjugate gradient (CG) method preconditioned ...
Takeshi Enomoto, Saori Nakashita
doaj   +1 more source

Mechanostimulatory Cues Determine Intestinal Fibroblast Fate and Profibrotic Remodeling in a Physiodynamic Human Gut‐on‐a‐Chip

Advanced Science, EarlyView.
A healthy gut barrier shields underlying fibroblasts from luminal shear forces, illustrating that “good fences make good neighbors.” Barrier damage exposes fibroblasts to shear stress, inducing cell death and the emergence of stress‐adapted, profibrotic fibroblasts. Sustained shear exposure promotes the formation of stiff aggregates of mechanoadapative
Soyoun Min, Nam Than, Yong Cheol Shin, Elif G. Ertugral, Chandrasekhar R. Kothapalli, Olumuyiwa Awoniyi, Hyun Jung Kim   +6 more
wiley   +1 more source

A Projection Strategy for Improving the Preconditioner in the LOBPCG

International Journal of Applied Mathematics and Computer Science
The computational methods for solving the generalized eigenvalue problems of real symmetric matrices are crucial in fields such as structural dynamics analysis.
Ma Tailai, Sun Shuli, Zheng Fangyi, Chen Pu   +3 more
doaj   +1 more source

Pseudoinverse preconditioners and iterative methods for large dense linear least-squares problems [PDF]

Bulletin of Computational Applied Mathematics, 2013
We address the issue of approximating the pseudoinverse of the coefficient matrix for dynamically building preconditioning strategies for the numerical solution of large dense linear least-squares problems.
Oskar Cahueñas, Luis M. Hernández-Ramos, Marcos Raydan   +2 more
doaj