Results 91 to 100 of about 21,724 (205)

Bayesian Approach to Ionospheric Elementary Current Systems Using Differentiable Basis Functions

Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.
Abstract Spherical elementary current systems (SECS) have become a widely used tool to model vector fields on spherical surfaces in ionospheric data analysis. The systems were originally formulated using point sources for the divergence and curl of the fields. In this paper we present a flexible alternative formulation, showing how continuous functions
S. Käki, J. Norberg, K. Kauristie
wiley   +1 more source

Smoothing Approximations for Least Squares Minimization with L1-Norm Regularization Functional

International Journal of Analysis and Applications, 2021
The paper considers the problem of least squares minimization with L1-norm regularization functional. It investigates various smoothing approximations for the L1-norm functional. It considers Quadratic, Sigmoid and Cubic Hermite functionals.
Henrietta Nkansah, Francis Benyah, Henry Amankwah   +2 more
doaj  

Demonstration of a family of X‐ray dark‐field retrieval approaches on a common set of samples

Journal of Synchrotron Radiation, Volume 33, Issue 2, Page 437-447, March 2026.
This study aims to guide users of dark‐field imaging in selecting the most suitable technique for their imaging goals. To this end, we provide a summary table and highlight opportunities for future research into the sources of dark‐field contrast across emerging methods.There are various imaging setups capable of capturing dark‐field images, each with ...
Samantha J. Alloo, Ying Ying How, Jannis N. Ahlers, David M. Paganin, Michelle K. Croughan, Kaye S. Morgan   +5 more
wiley   +1 more source

A PROPOSAL FOR REGULARIZED INVERSION FOR AN ILL-CONDITIONED DECONVOLUTION OPERATOR

CT&F Ciencia, Tecnología & Futuro, 2013
From the inverse problem theory aspect, deconvolution can be understood as the linear inversion of an ill-posed and ill-conditioned problem. The ill-conditioned property of the deconvolution operator make the solution of inverse problem sensitive to ...
Herling Gonzalez, Sheryl Avendaño, German Camacho   +2 more
doaj  

X‐ray waveguide optics at GINIX/P10 PETRA III: recent progress and future directions

Journal of Synchrotron Radiation, Volume 33, Issue 2, Page 298-313, March 2026.
X‐ray waveguide optics enable spatial and coherence filtering of a nano‐focused synchrotron beam and provide tailored illumination wavefronts for holographic imaging. Progress in fabrication, characterization and advanced waveguide interferometers can enhance holographic imaging.Here we report on recent progress in X‐ray waveguide optics for full‐field
Tim Salditt, Paul Meyer, Leon Merten Lohse, Jens Lucht, Jakob Soltau, Neele Kozák, Mike Kanbach, Markus Osterhoff, Fabian Westermeier   +8 more
wiley   +1 more source

QUILPEN Provides Independent and Label‐Free Single‐Cell Quantification of Pigmentation Dynamics and Organelle Content

Pigment Cell &Melanoma Research, Volume 39, Issue 2, March 2026.
Pigment‐associated cellular features, such as melanin levels and organelles, can be quantified in live cells with label‐free multimodal imaging. Quantitative phase imaging (cyan) measures cell mass, scattering (yellow) reports organelle content, including melanosomes, and absorbance imaging (magenta) captures pigment such as melanin.
Rebecca G. Zitnay, Shukran Alizada, Tarek E. Moustafa, Devin Lange, Luke Schreiber, Alexander Lex, Robert L. Judson‐Torres, Thomas A. Zangle, Rachel L. Belote   +8 more
wiley   +1 more source

Generalized Tikhonov regularization method for an inverse boundary value problem of the fractional elliptic equation

Boundary Value Problems
This research studies the inverse boundary value problem for fractional elliptic equation of Tricomi–Gellerstedt–Keldysh type and obtains a condition stability result.
Xiao Zhang
doaj   +1 more source

A Modified Landweber Algorithm for Inversion of Particle Size Distribution Combined With Tikhonov Regularization Theory

IEEE Access, 2018
Particle size distribution (PSD) measurement based on the static light scattering method has been widely used in the environmental field and combustion diagnostics, such as PM2.5 measurement and combustion process monitoring.
Ming Kong, Lixia Cao, Liang Shan, Yao Yang   +3 more
doaj   +1 more source

Cut Finite Element 3D Acoustic Shape Optimization of a Compression Driver Taking Viscothermal Losses Into Account

International Journal for Numerical Methods in Engineering, Volume 127, Issue 4, 28 February 2026.
ABSTRACT Wave propagation effects such as resonance and interference effects complicate the design of many acoustic devices, particularly when the dimensions of the device are in the order of the operating wavelength. At the same time, these complications also offer an opportunity for numerical optimization schemes to outperform designs achieved using ...
Martin Berggren, Anders Bernland, André Massing, Daniel Noreland, Eddie Wadbro   +4 more
wiley   +1 more source

Reconstruction of a source term in a parabolic integro-differential equation from final data

Mathematical Modelling and Analysis, 2011
The identification of a source term in a parabolic integro-differential equation is considered. We study the existence of the quasi-solution to this problem, Tikhonov regularization and a related gradient method.
Kairi Kasemets, Jaan Janno
doaj   +1 more source