Results 121 to 130 of about 1,481 (288)

Simultaneous T2, T2*, and R2′ Mapping for Multiple Sclerosis Using Nonlinear Model‐Based Reconstruction of Undersampled Radial RARE‐EPI MRI

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To demonstrate the synergy of undersampled radial 2in1‐RARE‐EPI acquisition and nonlinear model‐based reconstruction for accelerated and simultaneous T2, T2*, and R2′ mapping in brains of patients with multiple sclerosis (MS). Methods 2in1‐RARE‐EPI combines a RARE module with an EPI module to capture T2 and T2* information.
Jose Raul Velasquez Vides, Carl J. J. Herrmann, Thomas Gladytz, Hoby P. Hetherington, Hendrik Mattern, Xiaoqing Wang, Jason M. Millward, Shahriar Shalikar, Igor Fabian Tellez Ceja, Beate Endemann, Sonia Waiczies, Joseph Kuchling, Friedemann Paul, Georg Rose, Min‐Chi Ku, Franz Schmitt, Thoralf Niendorf   +16 more
wiley   +1 more source

Arc‐ZTE: Continuously‐Slewed Zero‐TE Imaging With Incoherent Temporal Sampling for Near‐Silent Dynamic MRI

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To enable flexible dynamic and DCE MRI with low acoustic noise and high spatiotemporal resolution using zero echo time (ZTE) imaging. Methods This work proposes Arc‐ZTE, a technique in which the readout gradients of ZTE are continuously‐slewed to form arcs in k‐space that are sequentially rotated to yield an incoherent trajectory ...
Shreya Ramachandran, Tobias C. Wood, Gavin Zhang, Ali B. Syed, Shreyas S. Vasanawala, Michael Lustig   +5 more
wiley   +1 more source

Preconditioned iterative solution methods for linear systems arising in PDE-constrained optimization

, 2019
This chapter is devoted to the preconditioned iterative solution of a particular type of linear systems, mainly involving matrices of a two-by-two block form with square matrix blocks.
Neytcheva, Maya,, Axelsson, Owe,, Karátson, János,   +2 more
core  

A theory of secant preconditioners

, 1993
In this paper we analyze the use of structured quasi-Newton formulae as preconditioners of iterative linear methods when the inexact-Newton approach is employed for solving nonlinear systems of equations. We prove that superlinear convergence and bounded
José Mario Martínez
core   +1 more source

A Machine Learning Approach to Predict Functional Performance From Measurable Protein Structural Characteristics: A Screening Tool for Protein Ingredient Quality

Proteins: Structure, Function, and Bioinformatics, EarlyView.
ABSTRACT The food industry is witnessing the emergence of specialized protein‐based functional ingredients for the use as gelling, thickening, and/or emulsifying agents in various food applications. Different sources of protein including species and cultivars, as well as variable processing conditions affect the protein's structural characteristics ...
Ronit Mandal, Sara Malvar, Ranveer Chandra, Baraem P. Ismail   +3 more
wiley   +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

An Empirical Analysis of the Performance of Preconditioners for SPD Systems

, 2012
Preconditioned iterative solvers have the potential to solve very large sparse linear systems with a fraction of the memory used by direct methods. However, the effectiveness and performance of most preconditioners is not only problem dependent, but also
Gupta, Anshul, George, Thomas, Sarin, Vivek   +2 more
core   +1 more source

Lagrangian analysis of two flavours of Central European heatwaves: Formation under omega blocking versus initiation by subtropical ridges

Quarterly Journal of the Royal Meteorological Society, EarlyView.
We investigate whether Central European heatwaves (HWs) forming under omega blocking differ from those enabled by subtropical ridges, in terms of both air‐mass origin and processes warming air parcels along their way. Using ERA5‐based backward trajectories and a Lagrangian temperature anomaly decomposition, we identify significant differences in the ...
Alexander Lemburg, Andreas H. Fink, Miguel M. Lima, Joaquim G. Pinto   +3 more
wiley   +1 more source

Element-by-Element Preconditioners for Large Partially Separable Optimization Problems

, 1997
International audienceWe study the solution of large-scale nonlinear optimization problems by methods which aim to exploit their inherent structure. In particular, we consider the property of partial separability, first studied by Griewank and Toint ...
L'Excellent, Jean-Yves, Gould, Nicholas, I. M., Daydé, Michel   +2 more
core  

Preconditioned iterative methods for weighted toeplitz least squares problems

, 2006
We consider the iterative solution of weighted Toeplitz least squares problems. Our approach is based on an augmented system formulation. We focus our attention on two types of preconditioners: a variant of constraint preconditioning, and the Hermitian ...
Benzi, Michele, Michael K. Ng, Michele Benzi, Ng, Michael K.   +3 more
core   +1 more source