13 citations · 34 across the 17 of their papers we have counts for
17 papers
Wavelet-based multilevel framework for -regularized image deblurring
Danyh Tolah, Malena I. Español, Misha E. Kilmer
Solving large-scale -regularized image deblurring problems efficiently while preserving sharp edges remains a significant computational challenge. We propose a wavelet-base…
Structure-Informed Bounds on the Kronecker Rank of Block-Structured Matrices
Allison Fuller, Malena Español, Misha Kilmer
We derive theoretical bounds on the Kronecker rank of block-structured matrices that possess both inner and outer structure. Building on the matrix-to-tensor and tensor-to-matrix f…
Qualitative reconstruction methods for imaging interior Robin interfaces in EIT from Robin-to-Dirichlet data
Rafael Ceja Ayala, Malena I. Español, Govanni Granados
We consider an inverse shape problem arising in electrical impedance tomography (EIT) for nondestructive testing, in which interior defects are modeled through Robin transmission c…
Variable Projection Methods for Solving Regularized Separable Inverse Problems with Applications to Semi-Blind Image Deblurring
Delfina B. Comerso Salzer, Malena I. Español, Gabriela Jeronimo
Separable nonlinear least squares problems appear in many inverse problems, including semi-blind image deblurring. The variable projection (VarPro) method provides an efficient app…
Efficient Decomposition-Based Algorithms for -Regularized Inverse Problems with Column-Orthogonal and Kronecker Product Matrices
Brian Sweeney, Malena I. Español, Rosemary Renaut
We consider an -regularized inverse problem where both the forward and regularization operators have a Kronecker product structure. By leveraging this structure, a joint de…
Parameter Selection by GCV and a test within Iterative Methods for -regularized Inverse Problems
Brian Sweeney, Rosemary Renaut, Malena Español
regularization is used to preserve edges or enforce sparsity in a solution to an inverse problem. We investigate the Split Bregman and the Majorization-Minimization iterat…
Convergence Analysis of a Variable Projection Method for Regularized Separable Nonlinear Inverse Problems
Malena I. Español, Gabriela Jeronimo
Variable projection methods prove highly efficient in solving separable nonlinear least squares problems by transforming them into a reduced nonlinear least squares problem, typica…
An Online Dynamic Amplitude-Correcting Gradient Estimation Technique to Align X-ray Focusing Optics
Sean Breckling, Leora E. Dresselhaus-Marais, Eric Machorro +15
High-brightness X-ray pulses, as generated at synchrotrons and X-ray free electron lasers (XFEL), are used in a variety of scientific experiments. Many experimental testbeds requir…
A Discrete-to-Continuum Model of Weakly Interacting Incommensurate Two-Dimensional Lattices: The hexagonal case
Malena I. Espanol, Dmitry Golovaty, J. Patrick Wilber
In this paper, we extend the discrete-to-continuum procedure we developed in our previous work to derive a continuum variational model for a hexagonal twisted bilayer material in w…
The Image Deblurring Problem: Matrices, Wavelets, and Multilevel Methods
David Austin, Malena I. Español, Mirjeta Pasha
The image deblurring problem consists of reconstructing images from blur and noise contaminated available data. In this AMS Notices article, we provide an overview of some well kno…
Aggregation Phenomena in Lyotropic Chromonic Liquid Crystals
Lidia Mrad, Longhua Zhao, Malena I. Español +2
We study the aggregation phenomenon in lyotropic chromonic liquid crystals as the molecular concentration changes and condensing agents are added into the system. Using properties…
Efficient edge-preserving methods for dynamic inverse problems
Mirjeta Pasha, Arvind K. Saibaba, Silvia Gazzola +2
We consider efficient methods for computing solutions to dynamic inverse problems, where both the quantities of interest and the forward operator (measurement process) may change a…
An Variable Projection Method for Large-Scale Separable Nonlinear Inverse Problems
Malena Espanol, Mirjeta Pasha
The variable projection (VarPro) method is an efficient method to solve separable nonlinear least squares problems. In this paper, we propose a modified VarPro for large-scale sepa…
A Discrete-to-Continuum Model of Weakly Interacting Incommensurate Two-Dimensional Lattices
Malena I. Español, Dmitry Golovaty, J. Patrick Wilber
In this paper we propose a continuum variational model for a two-dimensional deformable lattice of atoms interacting with a two-dimensional rigid lattice. The two lattices have sli…
A Discrete-to-Continuum Model of Weakly Interacting Incommensurate Chains
Malena Español, Dmitry Golovaty, J. Patrick Wilber
In this paper we use a formal discrete-to-continuum procedure to derive a continuum variational model for two chains of atoms with slightly incommensurate lattices. The chains repr…
Euler elastica as a -Limit of discrete bending energies of one-dimensional chains of atoms
Malena I. Espanol, Dmitry Golovaty, J. Patrick Wilber
This work is motivated by discrete-to-continuum modeling of the mechanics of a graphene sheet, which is a single-atom thick macromolecule of carbon atoms covalently bonded to form…
Optimal Regularization Parameters for General-Form Tikhonov Regularization
Julianne Chung, Malena I. Español, Tuan Nguyen
In this work we consider the problem of finding optimal regularization parameters for general-form Tikhonov regularization using training data. We formulate the general-form Tikhon…