Results 31 to 40 of about 413,861 (307)
A Learning-Based Method for Solving Ill-Posed Nonlinear Inverse Problems: A Simulation Study of Lung EIT [PDF]
SIAM Journal of Imaging Sciences, 2018 This paper proposes a new approach for solving ill-posed nonlinear inverse problems. For ease of explanation of the proposed approach, we use the example of lung electrical impedance tomography (EIT), which is known to be a nonlinear and ill-posed ...
J. Seo +4 more
semanticscholar +1 more source
Total Fractional-Order Variation-Based Constraint Image Deblurring Problem
Mathematics, 2023 When deblurring an image, ensuring that the restored intensities are strictly non-negative is crucial. However, current numerical techniques often fail to consistently produce favorable results, leading to negative intensities that contribute to ...
Shahid Saleem +2 more
doaj +1 more source
On the Convergence of Stochastic Gradient Descent for Nonlinear Ill-Posed Problems [PDF]
SIAM Journal on Optimization, 2019 In this work, we analyze the regularizing property of the stochastic gradient descent for the efficient numerical solution of a class of nonlinear ill-posed inverse problems in Hilbert spaces.
Bangti Jin, Zehui Zhou, J. Zou
semanticscholar +1 more source
ON THE DISCRETE LINEAR ILL‐POSED PROBLEMS
Mathematical Modelling and Analysis, 1999 An inverse problem of photo‐acoustic spectroscopy of semiconductors is investigated. The main problem is formulated as the integral equation of the first kind. Two different regularization methods are applied, the algorithms for defining regularization parameters are given.
openaire +4 more sources
Minimum Principles for Ill-Posed Problems [PDF]
SIAM Journal on Mathematical Analysis, 1978 Ill-posed problems $Ax = h$ are discussed in which A is Hermitian and postive definite; a bound $\| {Bx} \| \leqq \beta $ is prescribed. A minimum principle is given for an approximate solution $\hat x$. Comparisons are made with the least-squares solutions of K. Miller, A. Tikhonov, et al.
openaire +2 more sources
Numerical simulation of magnetic droplet dynamics in a rotating field
Mathematical Modelling and Analysis, 2013 Dynamics and hysteresis of an elongated droplet under the action of a rotating magnetic field is considered for mathematical modelling. The shape of droplet is found by regularization of the ill-posed initial–boundary value problem for nonlinear partial ...
Andrejs Cebers, Harijs Kalis
doaj +1 more source
Pediatric Blood &Cancer, EarlyView.ABSTRACT Pediatric supportive care clinical trials often involve multiple clinically important outcomes, complicating trial interpretation. Hierarchical composite endpoints (HCEs) provide a framework to integrate key outcomes according to clinical importance.
Willem H. Collier +11 more
wiley +1 more source
Nesterov’s accelerated gradient method for nonlinear ill-posed problems with a locally convex residual functional [PDF]
Inverse Problems, 2018 In this paper, we consider Nesterov’s accelerated gradient method for solving nonlinear inverse and ill-posed problems. Known to be a fast gradient-based iterative method for solving well-posed convex optimization problems, this method also leads to ...
Simon Hubmer, R. Ramlau
semanticscholar +1 more source
Design and analysis strategies for robust microbiome ageing research
FEBS Letters, EarlyView.The gut microbiome changes with age and associates with age‐related morbidity and mortality, establishing it as a potential biomarker and intervention target for ageing. Realising this potential requires methodological rigour, yet distinguishing biological signals from methodological artefacts remains challenging across cohorts. This review provides an
Mark Olenik +5 more
wiley +1 more source
Modelling and Simulation in Engineering, 2020 In many references, both the ill-posed and inverse boundary value problems are solved iteratively. The iterative procedures are based on firstly converting the problem into a well-posed one by assuming the missing boundary values.
Mohammed Hamaidi +3 more
doaj +1 more source