English
Related papers

Related papers: Comparison of R1 Mapping Protocols: What are we me…

200 papers

Functional neuroimaging measures how the brain responds to complex stimuli. However, sample sizes are modest, noise is substantial, and stimuli are high dimensional. Hence, direct estimates are inherently imprecise and call for…

Applications · Statistics 2016-02-05 Leila Wehbe , Aaditya Ramdas , Rebecca C. Steorts , Cosma Rohilla Shalizi

The single relaxation time (SRT) and the revised matrix (RM) lattice Boltzmann models are compared for simulations of three dimensional forced isotropic turbulence with resolutions of 128^3 and 256^3, respectively. The forcing technique by…

Fluid Dynamics · Physics 2023-06-08 Waleed Abdel Kareem , Pietro Asinari , Sauro Succi , Seiichiro Izawa , Yu Fukunishi

Fast Field-Cycling Nuclear Magnetic Resonance relaxometry is a non-destructive technique to investigate molecular dynamics and structure of systems having a wide range of applications such as environment, biology, and food. Besides a…

Correlation matrices are widely used to analyze the interdependence of variables in various real-world scenarios. Often, a perturbation in a few variables leads to mild differences in many correlation coefficients associated with these…

Applications · Statistics 2023-03-07 Itamar Faran , Michael Peer , Shahar Arzy , Yuval Benjamini

Despite the common usage of a canonical, data-independent, hemodynamic response function (HRF), it is known that the shape of the HRF varies across brain regions and subjects. This suggests that a data-driven estimation of this function…

Computational Engineering, Finance, and Science · Computer Science 2014-11-10 Fabian Pedregosa , Michael Eickenberg , Philippe Ciuciu , Bertrand Thirion , Alexandre Gramfort

The spin-lattice relaxation rate $T_1^{-1}$ of $^1$H-NMR has been measured in (CH$_3$)$_2$CHNH$_3$Cu(Cl$_x$Br$_{1-x}$)$_3$ with $x=0$ and 0.35, in order to investigate the microscopic magnetism of systems. Previous macroscopic magnetization…

Statistical Mechanics · Physics 2009-03-20 A. Oosawa , T. Suzuki , K. Kanada , T. Goto , H. Manaka

The site-selective nuclear spin-lattice relaxation rate T1^{-1} is theoretically studied inside a vortex core in a chiral p-wave superconductor within the framework of the quasiclassical theory of superconductivity. It is found that T1^{-1}…

Superconductivity · Physics 2009-11-07 Nobuhiko Hayashi , Yusuke Kato

The temperature dependences of spin-lattice relaxation time $T_1$ of $^{133}$Cs in CsFeCl$_3$ and $^{87}$Rb in RbFeCl$_3$ were measured in the temperature range between 1.5 K and 22 K, at various fields up to 7 T applied parallel (or…

Materials Science · Physics 2009-11-07 Mitsuru Toda , Takao Goto , Meiro Chiba , Naoshi Suzuki

We present a first-principles approach for computing the phonon-limited $T_1$ spin relaxation time due to the Elliot-Yafet mechanism. Our scheme combines fully-relativistic spin-flip electron-phonon interactions with an approach to compute…

Materials Science · Physics 2020-01-22 Jinsoo Park , Jin-Jian Zhou , Marco Bernardi

Psychiatric neuroscience is increasingly aware of the need to define psychopathology in terms of abnormal neural computation. The central tool in this endeavour is the fitting of computational models to behavioural data. The most prominent…

Quantitative Methods · Quantitative Biology 2018-03-28 Abraham Nunes , Alexander Rudiuk

The $R$-ratio is a phenomenological observable of great relevance, both in itself and in applications such as the dispersive approach to the muon anomalous magnetic moment. It can be investigated from first-principles with controlled…

The local number variance associated with a spherical sampling window of radius $R$ enables a classification of many-particle systems in $d$-dimensional Euclidean space according to the degree to which large-scale density fluctuations are…

Statistical Mechanics · Physics 2021-05-12 Salvatore Torquato , Jaeuk Kim , Michael A. Klatt

Accurate simulations of the flow in the human airway are essential for advancing diagnostic methods. Many existing computational studies rely on simplified geometries or turbulence models, limiting their simulation's ability to resolve flow…

Spin relaxometry using solid-state spin defects, such as the diamond nitrogen-vacancy (NV) center, probes dynamical processes by measuring how environmental fluctuations enhance the spin relaxation rate. In the weak-coupling limit,…

Mesoscale and Nanoscale Physics · Physics 2026-02-03 Ruotian Gong , Alex L. Melendez , Guanghui He , Zhongyuan Liu , Chong Zu , Huan Zhao

Reinforcement learning (RL) training is inherently unstable due to factors such as moving targets and high gradient variance. Reinforcement Learning from Human Feedback (RLHF) and Reinforcement Learning from AI Feedback (RLAIF) can…

Machine Learning · Computer Science 2025-06-24 Ju-Seung Byun , Andrew Perrault

Purpose: To address the systematic bias in whole-brain dual flip angle (DFA) T1-mapping at 7T by optimizing the flip angle pair and carefully selecting RF pulse shape and duration. Theory and Methods: Spoiled gradient echoes can be used to…

Medical Physics · Physics 2020-01-28 H. Olsson , M. Andersen , R. Wirestam , J. Lätt , G. Helms

We present an experimental and theoretical study of the longitudinal electron spin relaxation ($T_1$) of shallow donors in the direct band-gap semiconductor ZnO. $T_1$ is measured via resonant excitation of the Ga donor-bound exciton. $T_1$…

A recent interest in resting state functional magnetic resonance imaging (rsfMRI) lies in subdividing the human brain into anatomically and functionally distinct regions of interest. For example, brain parcellation is often used for…

Random features (RFs) are a popular technique to scale up kernel methods in machine learning, replacing exact kernel evaluations with stochastic Monte Carlo estimates. They underpin models as diverse as efficient transformers (by…

Machine Learning · Statistics 2024-10-04 Isaac Reid , Stratis Markou , Krzysztof Choromanski , Richard E. Turner , Adrian Weller

We measure the relaxation rate $W \equiv T_{1}^{-1}$ of a single electron spin in a quantum dot at magnetic fields from 7 T down to 1.75 T, much lower than previously measured. At 1.75 T we find that $T_{1}$ is 170 ms. We find good…

Mesoscale and Nanoscale Physics · Physics 2009-09-29 S. Amasha , K. MacLean , Iuliana Radu , D. M. Zumbuhl , M. A. Kastner , M. P. Hanson , A. C. Gossard