Results 111 to 120 of about 246 (200)

Linear Toroidal‐Inertial Waves on A Differentially Rotating Sphere with Application to Helioseismology: Modeling, Forward and Inverse Problems

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT This paper develops a mathematical framework for interpreting observations of solar inertial waves in an idealized setting. Under the assumption of purely toroidal linear waves on the sphere, the stream function of the flow satisfies a fourth‐order scalar equation.
Tram Thi Ngoc Nguyen, Damien Fournier, Laurent Gizon, Thorsten Hohage   +3 more
wiley   +1 more source

Composition of Fractional Integral and Derivative Operators: Summarised in Tables

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT This paper compiles a complete, detailed list of composition properties for Riemann–Liouville fractional differintegrals, in all possible cases for orders anywhere in the complex plane, with the results presented clearly in a table for easy visual consumption.
Arran Fernandez
wiley   +1 more source

Remarks on the Maximal Regularity for Parabolic Boundary Value Problems With Inhomogeneous Data

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT Inspired by Ogawa‐Shimizu and Chen‐Liang‐Tsai on the second and first order derivative estimates of solutions of the heat equation in the upper half space with boundary data in homogeneous Besov spaces, we extend the estimates to any order of derivatives, including fractional derivatives.
Hui Chen, Su Liang, Tai‐Peng Tsai
wiley   +1 more source

Enhancing Optical Lattice Clock Coherence Times with Erasure Conversion

PRX Quantum
Increasing coherent interrogation times is central to advancing the precision of optical clocks. Synchronous differential optical clock comparisons have now demonstrated atomic coherence times that far exceed the coherence time of the clock laser.
Shuo Ma, Jonathan Dolde, Xin Zheng, Dhruva Ganapathy, Alexander Shtov, Jenny Chen, Anke Stöltzel, Bennett J. Christensen, Shimon Kolkowitz   +8 more
doaj   +1 more source

A Magnetic Resonance Fingerprinting Approach for Simultaneous T1$$ {T}_1 $$‐ and PRFS‐Based 3D MR‐Thermometry

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To evaluate a three dimensional dual echo magnetic resonance fingerprinting sequence for simultaneous proton resonance frequency shift (PRFS) and T1$$ {T}_1 $$ thermometry during microwave ablation with T1$$ {T}_1 $$ improving robustness near gas bubble induced susceptibility changes while PRFS provides high precision elsewhere ...
Moritz Gutt, Dominik Horstmann, Othmar Belker, Simon Schröer, Daniel Düx, Frank Wacker, Marcel Gutberlet, Bennet Hensen   +7 more
wiley   +1 more source

Fast and Robust Diffusion Posterior Sampling for MR Image Reconstruction Using the Preconditioned Unadjusted Langevin Algorithm

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose The Unadjusted Langevin Algorithm (ULA) in combination with diffusion models can generate high quality MRI reconstructions with uncertainty estimation from highly undersampled k‐space data. However, sampling methods such as diffusion posterior sampling (DPS) or likelihood annealing suffer from long reconstruction times and the need for
Moritz Blumenthal, Tina Holliber, Jonathan I. Tamir, Martin Uecker   +3 more
wiley   +1 more source

N-body problem in $R^n$: Necessary conditions for a constant configuration measure

Electronic Journal of Differential Equations, 2008
A formulation of the N-body problem is presented in which $m_{i}$ and $r_{i}in mathbb{R}^d$ are the mass and the position vector of the i-th body, $ x=(sqrt{m_{1}}r_{1},dots ,sqrt{m_{N}}r_{N})in mathbb{R}^n$ and $ n=dN$ ($d=1,2,3$).
Kal Zare
doaj  

Single‐Shot 2D Radial Echo Planar Imaging for Functional MRI

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To develop a novel single‐shot radial echo planar imaging (ss‐rEPI) technique for rapid, distortion‐free brain imaging in functional MRI experiments. Methods Radial multi‐gradient echo (radial mGRE) data were acquired on a 3T clinical scanner using a 2D ss‐rEPI readout with small golden‐angle rotations between echoes.
Christoph A. Rettenmeier, Zidan Yu, Krystalyn Edwards‐Calma, Kai Tobias Block, V. Andrew Stenger   +4 more
wiley   +1 more source

Active Electromagnetic Interference Suppression for MRI and Proton Resonance Frequency Shift Thermometry During MRI‐Guided Microwave Ablation

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To develop a software‐based active electromagnetic interference (EMI) suppression (AES) framework on whole‐body multi‐channel MRI systems for reliable MRI and MR thermometry during MRI‐guided microwave ablation (MWA). Methods In addition to primary imaging coils, an unloaded standard body array coil was positioned outside the imaging ...
Qing Dai, Jason Chiang, Shu‐Fu Shih, Wenqi Zhou, David S. K. Lu, Holden H. Wu   +5 more
wiley   +1 more source

Methods for Uncertainty Quantification in Dictionary Matching to Advance Reliability of Quantitative MRI

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Aims Purpose: Dictionary matching is a standard tool in quantitative MRI (qMRI), but typically lacks uncertainty quantification (UQ). This is critical when advanced reconstructions (e.g., compressed sensing, deep learning) introduce complex‐valued, spatially varying, and temporally correlated noise that violates standard assumptions of ...
Brian Toner, Ute Goerke, Eze Ahanonu, Kevin Johnson, Vibhas Deshpande, Holden H. Wu, Maria I. Altbach, Ali Bilgin   +7 more
wiley   +1 more source